Servo Magazine 09 - 2015

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09.2015 VOL. 13

NO. 9

Columns 07 Robytes by Jeff and Jenn Eckert

Stimulating Robot Tidbits • Drones Receive Section 333 Exemption • Automatic Solar Duster • Want $150,000? • Robo Roach Sets Speed Record • Give a Bird the Bird(bot)

10 GeerHead by David Geer

Six Widely Varied Robot Finalists in Innorobo Call for Startups Companies vie for opportunities with investors and market exposure in this unique competition.

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14 Ask Mr. Roboto by Dennis Clark

Your Problems Solved Here Recap of the annual SparkFun Autonomous Vehicle Competition.

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74 Then and Now by Tom Carroll

What We’ve Learned from the DARPA Robotics Challenge In reality, the DRC was a huge success, despite some set-backs and falls.

Departments 06 Mind/Iron Workshop Air Quality Sensors

20 New Products 23 Events Calendar 27 Showcase 66 SERVO Webstore 80 RoboLinks 80 Advertiser’s Index

24 Bots in Brief • • • • • • •

Exo-lent Walking Assistance Explosive Jumping — Literally Fall into the Vortex Little People Pleasers Evolution of a Mother Robot SLAM Dunk on Improvements Robot Surgery is a Hit and MIS

19 MaxRoboTech Comics Contests Inspire Innovation

SERVO Magazine (ISSN 1546-0592/CDN Pub Agree#40702530) is published monthly for $24.95 per year by T & L Publications, Inc., 430 Princeland Court, Corona, CA 92879. PERIODICALS POSTAGE PAID AT CORONA, CA AND AT ADDITIONAL ENTRY MAILING OFFICES. POSTMASTER: Send address changes to SERVO Magazine, P.O. Box 15277, North Hollywood, CA 91615 or Station A, P.O. Box 54, Windsor ON N9A 6J5; [email protected]

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In This Issue ... 43 BooBits: Three Ghoulish littleBits Projects by Dave Prochnow It’s time to add some tricks to those treats with these three fun projects to do with kids (of all ages!) that will also teach some basic electronics.

48 BASIC Bots & PICAXE Processors by Eric Ostendorff Ready to try a different microcontroller in your robot builds? Well, this new series will show you how to work with a PICAXE 08M2+.

54 NASA’s 6th Annual Robotic Mining Competition by Holden Berry Teams from all over the country meet up again to compete in another out-of-this-world mining matchup.

57 BattleBots 2015 — That’s a Wrap by Michael “Fuzzy” Mauldin Take a closer look at some of the details of how this classic event was run and who ultimately took home the Giant Nut.

62 Let’s Talk Bots by Chris and Tiffany Olin Team Wrecks and Team Witch Doctor and Shaman open up about their experiences with the recently televised BattleBots competition.

69 Animatronics for the Do-It-Yourselfer by Steve Koci Run Away! It’s ParkerBot! Spiderman’s got nothin’ on this robotic arachnid that will add a whole new dimension to this year’s Halloween displays. PAGE 43

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The Combat Zone 28 BUILD REPORT A New Weapon for Spanky 31 PARTS IS PARTS HobbyKing CAR-45A Brushless Reversible Speed Controller 33 BUILD REPORT Viper Fighter Mark-2a 36 BUILD REPORT Splatter: The Evolution of a Combat Robot 38 EVENT REPORT Clash of the Bots 2015

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Mind / Iron by Bryan Bergeron, Editor ª

Workshop Air Quality Sensors Working with robotics — whether it be finishing the legs of a crawler with epoxy paint, soldering a chip to a printed circuit board, or cleaning the metal gears in a servo with Acetone — can be a potentially hazardous operation. Volatile organic compounds (or VOCs) expelled into the air can be dangerous to your health. To avoid permanent neurological damage, I do my best to open the windows and wear an appropriate breathing mask when I work with cleaners and other VOC producing substances. However, I often cheat on the small five minute projects. Not a good practice. The breathing masks with cartridges specific for various compounds aren’t that expensive — starting at about $30 for a basic mask from 3M and $10 for a pair of cartridges — but I’m not sure how well they work. I can’t tell when the cartridges are used up. Part of the problem is that many VOCs are odorless. Others have a sweet, almost pleasant smell. As a result, I’ve moved to “low VOC” solvents and chemicals, but they’re not always available and often don’t perform as well as conventional versions. I’ve also added VOC sensors and alarms to my workspace. I’ve found it’s much easier to limit the release of VOCs in my workshop rather than trying to filter them out later with a mask or move them outside with a fan. Commercial room VOC monitors are relatively expensive. A good VOC detector unit for the home or shop starts at about $300 (Amazon). A much more affordable approach is to build your own. For example, I built an Arduinobased detector/alarm for my shop for about $50, including a $20 VOC sensor board from SeeedStudio. You can also purchase VOC sensors from the usual supply houses (such as Digi-Key and Mouser) for $10-$20. I haven’t calibrated my detector, but it’s sensitive enough to sound off as soon as I open a container of cleaning fluid. That’s when I’m reminded to open the windows and turn on the fans and air conditioner. I can no longer get away with the quick five minute projects. Instead, I’m immediately reminded to put on my mask and open the windows. Even if you’re not interested in monitoring room air for volatile organic compounds, gas sensors are worth looking into. Imagine a robot constantly searching for gas leaks, or a “wash me” detector that lets you know it’s time to change and launder that shirt — a task that clearly qualifies for one of the four applications robots are known for: dull, dangerous, boring, and dirty. Keep your workshop healthy by looking into VOC detectors today. SV

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FOR THE ROBOT INNOVATOR

ERVO

Published Monthly By T & L Publications, Inc. 430 Princeland Ct., Corona, CA 92879-1300 (951) 371-8497 FAX (951) 371-3052 Webstore Only 1-800-783-4624 www.servomagazine.com Subscriptions Toll Free 1-877-525-2539 Outside US 1-818-487-4545 P.O. Box 15277, N. Hollywood, CA 91615 PUBLISHER Larry Lemieux [email protected] ASSOCIATE PUBLISHER/ ADVERTISING SALES Robin Lemieux [email protected] EDITOR Bryan Bergeron [email protected] VP of OPERATIONS Vern Graner [email protected] CONTRIBUTING EDITORS Tom Carroll Kevin Berry Dennis Clark R. Steven Rainwater David Geer Jeff Eckert Jenn Eckert Holden Berry Eric Ostendorff Michael Mauldin Chris Olin Tiffany Olin Dave Prochnow Steve Koci Pete Smith Mike Jeffries Matthew Vasquez CIRCULATION DEPARTMENT [email protected] WEB CONTENT Michael Kaudze [email protected] WEBSTORE MARKETING Brian Kirkpatrick [email protected] WEBSTORE MANAGER Sean Lemieux ADMINISTRATIVE STAFF Debbie Stauffacher Re Gandara Copyright 2015 by T & L Publications, Inc. All Rights Reserved All advertising is subject to publisher’s approval. We are not responsible for mistakes, misprints, or typographical errors. SERVO Magazine assumes no responsibility for the availability or condition of advertised items or for the honesty of the advertiser. The publisher makes no claims for the legality of any item advertised in SERVO. This is the sole responsibility of the advertiser. Advertisers and their agencies agree to indemnify and protect the publisher from any and all claims, action, or expense arising from advertising placed in SERVO. Please send all editorial correspondence, UPS, overnight mail, and artwork to: 430 Princeland Court, Corona, CA 92879.

Robytes by Jeff and Jenn Eckert Drones Receive Section 333 Exemption The FAA is taking a sometimes frustratingly incremental approach to UAS integration into US airspace. In general, to obtain the required Special Airworthiness Certificate for civil operations, "applicants must be able to describe how their system is designed, constructed, and manufactured, including engineering processes, software development and control, configuration management, and quality assurance procedures used, along with how and where they intend to fly." (Rumors that you also need to promise them your first-born are unconfirmed.) However, there is also the Section 333 Exemption, providing fast-track approval for operations in low risk controlled environments, and one was recently granted to Sky-Futures USA, Inc. (www.sky-futures.com) to conduct oil and gas inspections. The company's Ascending Technologies Falcon 8 drone is already performing the task elsewhere for such oil and gas companies as Talisman, Chevron, Conoco Philips, Apache, and others, and reportedly has logged 8,500+ hours providing live flare, structural, and underdeck inspections onshore and offshore. Using collected HD video, stills, and thermal imagery data, technical reports are written by in-house experts. By eliminating the risks and costs of sending out rope-climbers to do the job, Sky-Futures claims to offer savings of more than $4 million for offshore inspections. Reducing oil spills and other disasters isn't a bad feature, either.

Sky-Futures' Falcon 8 drone in operation.

Automatic Solar Duster Another bot that is taking over a job that is difficult and expensive for human beings is the Ecoppia (www.ecoppia.com) E4 Water-Free Solar Panel Cleaning Robot. Each unit is selfpowered and uses a self-maintained, water-free microfiber and airflow system that removes a claimed 99 percent of dust accumulation — even in harsh desert solar parks. Operation is fully automated, and the system includes "comprehensive monitoring and management tools." The robots move along a rigid aluminum frame using polyurethane-coated wheels to provide smooth movement with no load on the solar panel’s surface. Each robot is powered by Ecoppia's E4 solar panel cleaning robot. five electric motors that provide horizontal, vertical, and rotational movement. To maintain smooth upward and downward movement, the E4 robot uses a winch system with two flexible coated silicon rubber wires that operate angularly from opposite sides of the winch cylinder to the center point of the microfiber cylinder frame. Cleaning is performed at a pace of 108 ft2 per minute and typically takes place during the early hours to avoid shading during electricity generation hours. There is, of course, a video. Just search "ecoppia" at YouTube.

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Want $150,000? The Defense Advanced Research Projects Agency (DARPA, www.darpa.mil) has about $3 billion in research and development money to spread around every year, and much of it goes into robotic research. In the past, most of the funding has flowed to big defense industry players, but that is changing via the agency's Robotics Fast Track (RFT) program. According to program manager, Mark Micire, "We spend too much time creating three to four year solutions for six month problems. We want this new generation of robotics innovators to see DARPA as a partner that can help them develop breakthrough technologies in the areas that personally interest A TechShop facility where you might turn your robotic innovations into a fat government contract. them, and help translate their ideas and know-how into game-changing capabilities. We're eager to pioneer this new approach which could lead to rapid, marked improvements in national security as a whole." In practical terms, that means you can apply for one of DARPA's $150,000 grants if you can come up with innovations that address military objectives or other national security issues. The agency is working with the Open Source Robotics Foundation (OSRF, www.osrfoundation.org) to link to smaller organizations that aren't used to dealing with the government. You say you don't have the tools and facilities to bring your ideas to fruition? No worries! DARPA is cooperating with the growing number of TechShop (www.techshop.ws) facilities, where members have access to a fabrication and prototype studio, CAD systems, sophisticated tools, and a wide range of instructional classes. Membership in the San Francisco, CA location, for example, will run you as little as $125/month or $1,395/year. (You don't have to be a member to take classes.) To apply for the RFT program, just log onto rft.osrfoundation.org/apply.html. You could be on your way to becoming a successful defense contractor.

Robo Roach Sets Speed Record

The X-2 VelociRoACH launches an H2Bird ornithopter.

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Okay, it looks pretty much like all the other roachbots out there and doesn't do very much, but you have to be impressed by the X2VelociRoACH developed at UC Berkeley (www.berkeley.edu). The developers say it's the world's fastest legged robot of its size, meaning that it can be trounced by things like Boston Dynamics' Cheetah, which speeds along at 28.3 mph (45.5 kph). Cheetah is huge and complicated, however, whereas the X2 weighs only 1.9 oz (54 g) and is only 4 in (10.4 cm) long, but still zips across the floor at 11 mph (17.6 kph). Given that the X2's stride length is fixed, the only way to increase its speed was to make its motors run faster. The current design has a stride frequency of 45 Hz (i.e., 45 stride cycles per second), which is currently its structural limit. To keep pieces from flying off at such a high rate, it was fitted with fiberglass legs (instead of rubber), ripstop nylon joints, and carbon fiber reinforcement where needed. We should note that it isn't completely useless; it has been modified for use as a launch pad for Berkeley's H2Bird ornithopter micro aerial vehicle which can't get off the ground unless you somehow get it up to a speed of 1.3 mps. To see that happen, just search "h2bird" at YouTube.

Go to www.servomagazine.com/index.php/magazine /article/september2015_Robytes to comment on these topics.

Male (left) and female sage grouse.

Give a Bird the Bird(bot) Anytime you can be paid to simultaneously play with robots and study sex secrets, it's bound to be an interesting gig — even if you're just studying birds. In the case of UC Davis (ucdavis.edu) biologist, Gail Patricelli, it was an investigation into why a greater sage grouse named Dick has been so successful with the ladies while a majority of seemingly equally desirable males just can't get no satisfaction. According to researchers, Dick once accomplished 30 copulations in a single morning — 23 of them in as many minutes. The sage grouse is famous for its "elaborate, vaguely obscene mating ritual" in which they swish their wings over their chests, gulp air into their esophaguses (thereby inflating dual air sacs on their breasts), and make a strange "pop-whistle-pop" sound. To fully understand the nuances, Patricelli decided to create a couple fembots that could interact with Dick and make videos of his hours-long dances. Dubbed Salt and Pepa, they consisted of electromechanical innards covered with real female skins salvaged from Fish and Game Department freezers. They look pretty real except for the four wheels, but that level of realism was probably not necessary as the males have been known to try mating with dried cow pies when nothing better was available. The only conclusions so far are that Dick and his ilk produce good sound, tend to have fewer scars on their air sacs, and tend to have lots of hens surrounding them. Research continues ... SV

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GEERHEAD

by David Geer [email protected]

Six Widely Varied Robot Finalists in Innorobo Call for Startups European Competition Tests Robot’s Metal (or plastic, as the case may be) Innorobo is a leading European contest/event for robotics startups that may be from just about anywhere globally. The yearly event offers support to the top five — this year, six — entrants. The prize: A free stand at the Innorobo 2015 event from July 1st through the 3rd in Lyon, France, where they can press the flesh and seek investment from audience members and, on July 2nd, to an international panel of investors. This year’s six finalist companies included Reach Robotics, OptoForce, Robotbase, Flyability SA, Empire Robotics, and MagnebotiX. Let’s take a look at these robotic entries. 10

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Reach Robotics/Mecha Monsters Reach Robotics’ Mecha Monsters (still in the prototyping phase) bring the game play of virtual sim worlds into the physical world with small fighting robots that duke it out in real life. This isn’t BattleBots™. This is robots acting out the same kind of game play you would engage in video games but with a physical component. One of the coolest things about Mecha Monsters is that you probably already own the RC device: It’s your Apple or Android smartphone or tablet. With the app (as yet unnamed and not available for download) from Reach Robotics and Bluetooth technology, game play is framed in a responsive, colorful, user-friendly interface.

Artist’s rendering of Mecha Monsters — the world’s first computer gaming robots which bring avatars out of the virtual world and into reality.

Monthly coverage of commercial, unique, and military robotics.

Post comments on this article at www.servomagazine.com/index.php/magazine/article/september2015_GeerHead.

Like so many modern robots, the Mecha Monsters leverage the science of inverse kinematics where roboticists calculate the joint angles that coincide with optimal end effector placements in a given space. Mecha Monsters achieve three degrees of freedom per each of four legs using micro servos. End-users in game play only concern themselves with high level moves and strategy, while the robot technology does the rest. Unlike 3D sim games played out in virtual reality, Mecha Monsters open up software development to the gamer to write new capabilities for their robots. Since gamers assemble their robots from parts that allow for customization, each robot can be as unique physically as it is in capabilities. Reach Robotics will save every user’s gaming experience with Mecha Monsters to their user account on Reach Robotics servers. Follow their progress toward completion and commercial production at www.reachrobotics.com.

OptoForce — a Maker of Force Sensors OptoForce creates force sensors that enable endeffectors to sense force feedback in the same precise manner as the human hand does. With an end game of drastically advancing the tactile sensation capabilities of robot hands for collaboration between men and robots, OptoForce is researching human tactile sensing in order to add those capabilities to robots. Current OptoForce products include a three-axis force sensor and a six-axis force torque sensor. According to OptoForce, the three-axis force sensor can measure gripping and touching forces, as well as any slippage of grip in order to give feedback to the system to compensate. End-effectors can safely overload the force sensor by up to 600 percent of the nominal value. Every force sensor has a range of forces (e.g., 0-100N) that it can reliably measure. This is usually called the nominal capacity, full scale, or as in the above, the nominal value — with nominal capacity being the most used expression. A 600 percent overload capability means that you can load a 100N sensor with up to 600N without causing any damage to the sensor, according to an OptoForce representative. The sensor is equipped with a silicone surface for quality sensory data intake, while maintaining a high resistance to heat, water, and acid. Rather than use strain-gauge based load cells for sensing, OptoForce applies robust transducers with deforming surfaces that are separate from the sensing element. OtpoForce uses infrared light to detect minute surface deformations and variegated optical grade elastomers to produce highly reliable results. OptoForce’s six-axis force torque sensor offers a wide range of measurement that can be overloaded without

An end-effector that uses OptoForce force sensors. assuming inaccuracies or failures. Peruse their offerings at http://optoforce.com.

Robotbase — Maker of Robotic Digital Assistants The personal robot or robotic digital assistant automatically links to and manages all in-home or in-office connected devices and smart home technologies such as fitness trackers, locks, switches, outlets, and thermostats. Using a layer of advanced AI algorithms on top of all the connected devices, the robotic digital assistant will keep the home or office extremely secure while saving on energy bills by automatically rotating personalized comfort zones in the milieu according to your current environment, preferences, and time of day. It manages other smart home settings, as well. The robot digital personal assistant can pay for dinner and automatically track caloric consumption. It can call a taxi cab as soon as the user leaves the office. It can take a picture immediately when the user strikes a pose. It can

Resources Innorobo — www.innorobo.com Reach Robotics — www.reachrobotics.com OptoForce — http://optoforce.com Robotbase — www.robotbase.com/robot Flyability SA — www.flyability.com Empire Robotics — www.empirerobotics.com MagnebotiX — www.magnebotix.com SERVO 09.2015

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The robot digital assistant — the one with the face on it — from Robotbase, in a smart home setting with the technologies it controls for you labeled. determine mood, and play the appropriate song accordingly. The artificial intelligence in the assistant recognizes your face and your mood. It can interpret what you say to determine what you are really trying to communicate. It grows in learned intelligence daily based on its interactions with you. Robotbase offers a good selection of different personal robotic assistants. Each robotic digital assistant has its own face, personality, and talents. You can use the assistant to control household devices with your voice. You can ask questions about weather, news, sports scores, and general information. The assistant can schedule meetings, set alarms and alerts, retrieve recipes, and hear and understand you from a distance using noise cancelling microphone array technologies and proprietary natural language interpreting algorithms. The assistant communicates with all your connected devices via Wireless Z-Wave Plus, Zigbee, BLE, and Wi-Fi. The robot speaks to you and moves around the house using mapping and navigation algorithms. The robotic digital assistant is your personal security guard, transferring real time video of every room in the house. The assistant enables video chat and other services. Check it out at www.robotbase.com/robot.

Gimball uses obstacles instead of avoiding them. There is no need to be a world-class pilot to get it to the most inaccessible places. “Gimball can use the obstacles to guide its course. For instance, it can follow a hallway by rolling on the ceiling without needing precise piloting. It can enter a building through a small opening by rolling on the walls until it reaches an open window,” says Patrick Thevoz, CEO, Flyability SA.Gimball operation is user-friendly and safe for everyday people. Due to its light weight and protective cage, a person can touch the robot in flight without risk of personal injury. When flying, the Gimball’s HD camera can detect features <0.2 mm. It has its own lighting system and can view in all directions. The flying robot maintains its stability even after colliding with objects. Its rotating protective frame — which is patented — together with its flight control algorithms enable it to navigate in new ways. The inner frame stabilizes flight using a coaxial motor, two control surfaces, the battery, an IMU, and control electronics. In case of collision, Gimball’s spherical protective frame prevents obstacles from touching the inner frame and can passively rotate thanks to its gimbal system. The flying robot maintains its center of mass and orientation regardless of outer frame collisions, according to the company. Go to www.flyability.com to find out more.

Flyability SA/Gimball

Empire Robotics — Maker of End-Effectors

According to Flyability SA, Gimball operates using a gimbal system — a two thousand year old invention for decoupling two objects. Gimball is a collision-tolerant flying robot drone from Flyability SA that uses a shield to tolerate collisions while flying anywhere and everywhere. Gimball can explore chimneys, houses, collapsed buildings, and similar spaces without risking crashing into things.

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According to Empire Robotics, their Versaball endeffector system grips porous and delicate parts like no other end-effector design can. It can hold objects firmly and eliminates pinch points. It easily adjusts to variations in objects handled. The end-effector uses the jamming phase transition of granular materials to grip things.

This end-effector is already at work in collaborative robotics and agile manufacturing automation fields. The Versaball is filled with sand-like material. When air pumps into the ball, the ball softens. The robot then pushes the ball against the object it will grasp. Removing the air from the ball jams the material together, causing the ball to harden around the object. See http://empire robotics.com for additional details.

A close-up of MagnebotiX’s RodBot.

MagnebotiX — Maker of Nano Robots MagnebotiX develops magnetic manipulation systems, including magnetic field generators and micromagnetic agents. The MFG, or Magnetic Field Generating System, is capable of generating a wide variety of static or varying magnetic fields. Their RodBot is a wireless, mobile, rodshaped microrobot that is guided and powered by an externally applied magnetic field. Products such as the MFG100 use eight stationary electromagnets with ferromagnetic cores to produce arbitrary magnetic fields and field gradients at various frequencies. The MFG-100-I is easily incorporated into an inverted microscope system. Combined with high resolution optics,

the MFG-100-i enables the investigation of cellular mechanics, as well as 5-DOF dexterous manipulation at tiny scales, according to MagnebotiX. Learn more at www.magnebotix.com.

Conclusion These six impressive robots show promise for the future and demonstrate varied robotics expertise. SV

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ASK MR. ROBOTO

by Dennis Clark Our resident expert on all things robotic is merely an email away.

[email protected]

Tap into the sum of all human knowledge and get your questions answered here! From software algorithms to material selection, Mr. Roboto strives to meet you where you are — and what more would you expect from a complex service droid?

T

his year, I got the opportunity to visit the SparkFun facility at their annual Autonomous Vehicle Competition (AVC), which is just down the road from me in Boulder, CO. SparkFun has a new building from my last visit, so I really wanted to see what was different there as well as see another AVC. So, Mr. Roboto pinned his press badge to his hat and went to see what the excitement was all about. First impression: Wow! There were business booths, display booths, the robot course, an Ant and Beetleweight combat competition area, demonstrations, classes, workshops, the SparkFun store and, finally, the facilities tour (Figures 1 through 5). Their current place is much larger than their last, and the competition area was also expanded and easier to see. The whole course was in one place so you didn’t have to chase robots all around the building any more. In addition, there were third-party booths showing things that you

could buy, make, or work on. The theme here was obvious: “Learning Electronics is Fun.” This is pretty much the SparkFun mantra, and all of the booths were about learning, making, and having fun while doing it. There was no way I could capture everything going on at this event in one of my columns — even a one hour TV show would have trouble doing that in a way that gave viewers/readers a full understanding. So, rather than trying and failing, I will relay the highest points and show lots of pictures. I say highest points because everything was a

Figure 1.

Figure 2.

Figure 3.

Figure 4.

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Your robotic problems solved here.

Post comments on this article at www.servomagazine.com/ index.php/magazine/article/september2015_MrRoboto.

Figure 5.

Figure 6.

“high” point for me. I spent all day there, and went home tired and psyched!

Exhibits and Booths The first things that a gawker sees when entering the “gate” are the booths. The initial display I saw was the Hackster.io Hack to the Future Delorean. Hackster bills itself as a community of makers that arrange for everyone to show off and share their expertise and projects. The Hackster Delorean is basically a community project to see how many cool hacks can be stuffed into a car deliberately chosen as the hacker project of all hacker projects. The Delorean is a pop-culture icon to those who know the movies (You know who you are and what I am talking about!) ... remember the “flaming time travel tire tracks?” Well, the Hackster Delorean can do that! They have lots of other projects in the works, so go to the Hackster site to check things out (Figure 6). There were plenty of booths promoting learning toys and classes, so while being lost in a daze most of the time, I managed to take a few notes about some of the more interesting (to me) displays. In one booth, Lulzbot showed 3D printer outputs made from the plastic of recycled bottles called “Tglaze.” It was tough and flexible, and because it was recycled, doubly cool. The “Structobot” booth — makers of Kinetic Sand (available at educational toy stores now) — displayed their Structobot series of toys, which included some online open source parts to make robots that will be released soon (Figures 7 and 8).

Beetleweight belligerents and their arenas don’t take up much space. There were plenty of competitors from all over the USA there (Figure 9).

Battling Bots

Indoors

Combat bots are a crowd pleaser and these Ant and

Figure 7. Figure 8.

Inside were soldering classes, “Maker” workshops, the SERVO 09.2015

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Figure 10.

Figure 9.

Figure 11. SparkFun store, and the plant tours. I didn’t get my act together in time to get on a tour, so sorry — no insider shots of the manufacturing and classes housed in the SparkFun facility (maybe next year). SparkFun has the space in their new building to have an actual physical store. Talk about a toy store! Lots of kits, boards, and demonstrations were on display. The store was packed every time I went inside to get away from the heat (Figures 10 and 11).

The AVC Competition Oh yeah, there was also the Autonomous Vehicle Competition going on at the same time as everything else. There were over 70 entries this year that were divided into several classes, named: Doping, Micro/PBR, NonTraditional Locomotion, and Peloton. No one seemed to fully understand the differences, and no one appeared to really care. Check out the SparkFun site if you are interested

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in the details (https://avc.sparkfun.com/2015). Finally, there was the Student Class which could be combined with any other class for a team composed primarily of high school students. You could potentially win twice. There were no aerial classes this year. The new SparkFun site is too close to a highway, and while the six foot fence does a good job of keeping the ground vehicles in check, the flying vehicles can’t be stopped if they go rogue (and there is always at least one that does). My experience with the flying robots in the past is that they had gotten kind of boring, anyway. With the onset of truly excellent IMUs for single- or multi-rotor flyers, they have gotten so precise that they’re almost too predictable (in my perhaps not-so-humble opinion). It is also somewhat difficult to create an obstacle course for flying vehicles that will also be safe for spectators. A lot of ingenuity, engineering, and dedicated people are required to pull off such a large event like the AVC. In Figures 12 and 13, Toni is calling the heats and there’s a shot of the audio, video, staging, and recording consoles in constant use, as multiple heats of multiple types of robots are run and scored. I talked with Timm — SparkFun’s new director of Software and IT — about the AVC while roaming the pits. Please note that even though I was consuming a liter of water an hour here (SparkFun was handing out free bottled water all day), I was probably a little heat-dazed, or perhaps just dazed, so my quotes are really only paraphrased ... Not surprisingly, Timm’s comments were also in the educational theme: “We have this event and include a Student Class in

Figure 12. the competition to encourage high school age kids to participate and learn that technology can be fun as well as useful.” Here are some highlights from this competition. The first robot to successfully navigate the course was Auton made by Srinivas Raj (Figure 14). You can get extra points

Figure 13. if you don’t use a GPS to guide your robot. In fact, two robots — built by the brothers, Nathan and Richard Burnside — won their divisions by using dead reckoning on gyros that were sampled at a 1 kHz rate and integrated with a 32-bit value. Since their times were both around 20 seconds, the gyro drift was negligible (Figures 15 through 17).

Figure 14.

Figure 15.

Figure 16.

Figure 17. SERVO 09.2015

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Figure 18. They were the only robots to successfully negotiate the “discombobulator,” which was a spinning turntable with ramps on either side that allowed a competitor to cut the course in half if they survived the encounter. Sadly, none of the Non-Traditional Locomotion class of walkers and hovercraft made it much past the first corner. Maybe next year, guys! Rather than write down all of the standings, I included photos of the leader boards at the end of the event in Figures 18 and 19.

Figure 19.

Figure 20.

At the end of the day, we were treated to a live performance of a YouTube video from “Arduino Woman” Tenaya Hurst of Rogue Making (www.RogueMaking.com) who sells a line of wearable technology and promotes “making” for those that don’t build robots, but do like to make fashionable tech (Figure 20). I am exhausted all over again just reliving the event! If you can get to this competition, you should go. I’ll be back again next year — maybe I can even bring a robot! Well that’s it for another month. I hope you were inspired. Now, go out and make something new and fun for yourself! As usual, keep those questions coming to [email protected] and I’ll do my best to answer them. SV

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NEW PRODUCTS products. The 785 Gear Rack Kit is great for steering racks and other applications that require linear motion using a PWM signal. The HS-785HB servo rotates approximately 1.7 degrees/microsecond change in signal. To achieve full travel, a signal range from approximately 850-2150 µsec will be required (each HS-785HB servo responds to a signal slightly differently, so you may need to fine-tune this range in order to achieve full travel without hitting the stops at the ends). On a standard RC transmitter and receiver (assuming a 1050-1950 µsec range) the Gear Rack Kit will travel approximately 6.7”. It is priced at $89.99.

HS-785HB Channel Slider Kit

T

he HS-785HB Channel Slider Kit from ServoCity also provides an excellent way to create linear motion using a rotational servo. The unique Hitec HS-785HB servo (included in the kit) can rotate multiple turns while retaining positioning feedback which makes it perfect for this type of

HS-785HB Gear Rack Kit

T

he 785 Gear Rack Kit available from ServoCity is a simple way to create linear motion using a rotational servo. The kit comes with the multi-rotation Hitec HS-785HB servo which allows for up to 9.6” of travel when sending the proper PWM signal from a servo controller. The kit is constructed of 6061 T6 aluminum components and wearresistant Delrin plastic to create a durable yet lightweight assembly. The framework has several mounting options and integrates seamlessly with the rest of the Actobotics line of

application. The XL timing belt and XL pulleys offer a reliable way to transfer the rotation of the servo into a smooth linear motion down the 24” channel backbone. Total usable travel is approximately 19.25” and the rate of travel is .47”/second while running on 6V. Whether you’re building a replica, a pick-and-place machine, or a telescoping arm, this kit can help put your project in motion. The framework is constructed entirely of Actobotics parts which simplifies connecting additional components to it. Price is $169.99. For further information, please contact:

ServoCity

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www.servocity.com

Robot Controller Board

M

ikronauts — a manufacturer of add-on boards for the Raspberry Pi — has launched an affordable all-in-one educational robot controller for servos, PWM, and digital I/O, with analog inputs and dual H-bridge motor drivers for any model of the Raspberry Pi. Pi Droid Alpha is Mikronauts new robot controller board designed specifically for the educational and maker markets. Since the launch of their RoboPi advanced robot controller, Mikronauts has received a lot of feedback from teachers who loved RoboPi for advanced robots, but wished there was a controller for simpler robots. Specifically, they asked for: 1. Low cost (due to shrinking budgets) 2 An integrated motor driver 3. Something simpler to assemble (fewer components) Pi Droid Alpha addresses each of the points above, and is an ideal match for small robot chassis such as the Dagu Magician 2WD. A full kit of the Pi Droid Alpha is available in sample

Projected-Capacitive Touch Screen Controller

M

icrochip Technology, Inc., announced a new addition to its Human Interface Solutions portfolio with the MTCH6303: an innovative turnkey projected-capacitive touch controller for touch pads and screens. Touch sensors with up to 1,000 nodes and diagonals of up to 10” are supported. The MTCH6303 provides multi-touch coordinates as well as a ready-made multi-finger surface gesture suite

quantities from the company’s eBay page. Mikronauts welcomes distributor, reseller, and educational volume purchase inquiries at [email protected] For further information, please contact:

Mikronauts

www.mikronauts.com

noise-avoidance techniques and predictive tracking for 10 fingers at scan rates of up to 250 Hz with a minimum of 100 Hz each for five touches. It also combines with Microchip’s MTCH652 high voltage line driver to achieve a superior signal-to-noise ratio (SNR) for outstanding touch performance in noisy environments. When combined with the MGC3130, the MTCH6303 solution is capable of supporting 3D air gestures up to a 20 cm distance from the touch panel. Microchip’s MGC3130 Efield-based 3D tracking and gesture controller includes Microchip’s patented GestIC® technology, allowing user input via natural hand and finger movements in free space. This unique combination empowers designers to create interface-control possibilities in two and three dimensions. The MTCH6303 is supported by Microchip’s new MultiTouch Projected Capacitive Touch Screen Development Kit (part # DV102013, $149.99) which includes free downloadable software. For further information, please contact:

Microchip Technology, Inc.

that brings modern user interface (UI) elements — such as pinch and zoom, multi-finger scrolling, and swipes — to any embedded design with minimal host requirements. The MTCH6303’s advanced signal processing provides

www.microchip.com

WOMBAT Prototyping Board

A

nyone interested in creating their own Raspberry Pi projects should take a look at the Wombat prototyping board, recently released by Gooligum Electronics. It’s SERVO 09.2015

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SERVO 09.2015

designed to make it easy to prototype original circuits that connect to a Raspberry Pi — whether playing with ideas or designing a new product — freeing up time from the nitty gritty so the more challenging task of seeing a design come to fruition can be focused on. The newer Raspberry Pi models provide 40 GPIO pins which is great for experimenting and product development. However, connecting those pins to circuits can be messy and error-prone. The Wombat simplifies access to the Pi’s GPIO pins by breaking them out to a clearly labelled header alongside a large solderless breadboard (mounted on a sturdy base supported by rubber feet), which won’t limit users to building small projects. Although the Pi’s GPIO pins operate at 3.3V, its onboard 3.3V regulator is not intended to power external devices, so the Wombat includes a 3.3V regulator which can supply up to 500 mA — enough to power more complex projects. The Wombat also provides eight analog input pins (something the Raspberry Pi lacks) for use with analog sensors, along with a trimpot that can be deployed as a simple analog control. It includes a number of LEDs and pushbutton switches for use as digital outputs and inputs, or for testing. The analog inputs along with the LEDs and pushbuttons are all made available through a Python module. The functions are fully documented and clear examples are provided, making it easy to adapt them to a

project, using them in Python 2 or 3 programs. For those not using Python, the comprehensive documentation includes full schematics. The Wombat adds a USB serial console to the Raspberry Pi via a genuine FTDI serial-to-USB bridge, making it possible to set up a Pi or debug problems when the Pi is running headless and the network connection isn’t set up yet — such as when taking a Pi to a makerspace or jam. The Wombat’s micro USB connector can also be used instead of the Pi’s power connector to run both the project and the Pi. The Pi and project can be powered and controlled all through a single cable (as long as the laptop’s USB port supplies enough current; many can), making for a very clean uncluttered setup. A set of introductory projects featuring an RGB LED and light and temperature sensors is bundled with each board, including all the project components and a set of breadboard jumpers. Each project is fully documented with source code provided. The Wombat board retails for $50. Bulk purchase and educational discounts are available. For further information, please contact:

Gooligum www.gooligum.com Electronics

EVENTS Know of any robot competitions I’ve missed? Is your local school or robot group planning a contest? Send an email to [email protected] and tell me about it. Be sure to include the date and location of your contest. If you have a website with contest info, send along the URL as well, so we can tell everyone else about it. For last-minute updates and changes, you can always find the most recent version of the Robot Competition FAQ at Robots.net: http://robots.net/rcfaq.html. — R. Steven Rainwater

SEPTEMBER 29-30 4-7

DragonCon Robot Battles Atlanta, GA Autonomous and remote control robot battles in various weight ranges. www.dragoncon.org

5-6

European Rover Challenge Regional Science-Technology Centre, Podzamcze, Poland Student teams build rovers for a simulated Mars environment. www.roverchallenge.eu

5

Robotour Písek, Czech Republic Autonomous robots must navigate a park while carrying a 5L barrel of beer. www.robotika.cz

12

National Junior Robotics Competition Science Centre, Singapore Robots built by student teams in three age ranges compete in challenges. www.njrc.com.sg

15-18

International Micro Air Vehicle Competition Aachen, Germany Indoor and outdoor events for remote control and autonomous MAVs. www.imavs.org

17-25

euRathlon Piombino, Italy Autonomous robots compete in a simulated disaster response scenario. www.eurathlon.eu

25-27

RoboCup Junior Australia Adelaide, Australia Robots built by student teams compete in rescue and soccer challenges. www.robocupjunior.org.au

UAV Outback Challenge Australia Events include the UAV Airborne Delivery Challenge and the UAV Robotic Delivery Challenge. www.uavoutbackchallenge.com.au

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bots

IN BRIEF

EXO-LENT WALKING ASSISTANCE

T

he Personal 6.0 Exoskeleton from ReWalk Robotics is the company’s sixth generation product that is designed for people who suffer spinal cord injuries. This FDA-approved exoskeleton offers the fastest walking speed (up to 1.6 MPH) and the most precise fit of any ReWalk exoskeleton to date. The battery-powered system features a light,wearable exoskeleton with motors at the hip and knee joints. The ReWalker controls movement using subtle changes in the user’s center of gravity. A forward tilt of the upper body is sensed by the system, which initiates the first step. Repeated body shifting generates a sequence of steps that mimics a functional natural gait of the legs. The Personal 6.0 Exoskeleton is fitted to the user’s measurements and custom ordered for each individual. This precise fit enhances system function, safety, and alignment of the person’s joints. It also doesn’t have a backpack (like previous versions) to eliminate weight from the shoulders and give freedom for clothing choice and movement. The sleek redesign of the strapping and padding provides users with an easier and faster capacity to put the system on and take it off.

EXPLOSIVE JUMPING — LITERALLY

T

Image courtesy of Wyss Institute and Harvard School of Engineering and Applied Sciences.

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he Harvard Microrobotics Laboratory team in collaboration with UCSD researchers has completed a redesign of a robot that can jump and land upright. What’s especially cool is how they did it: with a multimaterial 3D printer that lets them fabricate a robot with the optimal combination of soft and rigid structures. It’s an actual butane-oxygen explosion that gets the bot off the ground. On top of the robot, there’s a core module with a custom circuit board, a high voltage power source, a battery, a miniature air compressor, a butane fuel cell, six solenoid valves, an oxygen cartridge and pressure regulator, and ducts to move the gas and stuff around as necessary. To jump, the robot first aims itself by selectively inflating one or more of its pneumatic legs to point its body in the direction that it wants to go. Then, it fills its body with a mixture of oxygen and butan and ignites itself — which rapidly expands the flexible bottom of the robot to launch it into the air. The robot can jump more than 20 times in a row, reaching 0.75 meters in height (six times its own height) and 0.15 meters laterally. Different parts of the robot grade over three orders of magnitude from stiff-like plastic to squishy-like rubber, through the use of nine different layers of 3D printed materials. For the main hemispherical chamber in the body of the robot (the bit that pops), for example, the top is stiffer to allow the core module to attach and to help transfer the energy of the explosion to the bottom of the hemisphere which is the bit that expands downward to launch the robot. Going too rigid would cause the robot to smash into tiny bits on impact, and too squishy would reduce the efficiency of the jumps.

bots

IN BRIEF FALL INTO THE VORTEX

V

ortex — a new robot from DFRobot — has joined the growing number of toys designed to teach children how to program. The robot — which can connect to iOS and Android devices — is designed for kids as young as six years old. The robot comes ready to play a number of games, including bumping fight, golf, driving, and soccer. All you have to do to get started with these games is add four AA batteries to Vortex and download the Vortexbot app from the App Store. The idea is that children will want to learn how to make Vortex do more with custom programming. To do so, the WhenDo app is downloaded from the App Store, and has a variety of tutorials so kids can practice programming basics and customize their games. DFRobot says WhenDo is intuitive with its drag-and-drop interface, however, parents might have to help kid(s) really master the app. Vortex will also come with pre-set courses to teach “students” how to make use of its built-in capabilities. Vortex — which is open source and compatible with Arduino and Scratch — can navigate obstacles, detect lines, and report back by using infrared, gray scale, and sound speakers. The wheeled robot features ground/line following sensors, proximity sensors, and encoders for speed control.

LITTLE PEOPLE PLEASERS

J

apanese robot maker, Vstone and telecom company, NTT announced plans to market little humanoids that can interact with people and also with devices around the house. In a recent press conference in Tokyo, the desktopsize robots — called CommU and Sota — held conversations with two lifelike female androids and a male android.

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EVOLUTION OF A MOTHER ROBOT

W

hen creating a brand new robot, it’s usually a good idea to design and test it in simulation first, to get a sense of how well the design will work. However, even a successful simulated robot will only provide limited insight into how it’s actually going to do once you build it. This fundamental disconnect between simulation and reality becomes especially problematic when you’re dealing with an area of robotics where it’s impractical to build physical versions of everything. Evolutionary robotics is a good example of this, where robot designs are artificially tested and iterated over hundreds (or thousands) of generations. It works great in simulation (if you have a fast computer), but is much harder to do in practice.

In a paper recently published in PLOS ONE, Luzius Brodbeck, Simon Hauser, and Fumiya Iida from the Institute of Robotics and Intelligent Systems at ETH Zurich took things one step farther by teaching a “mother robot” to autonomously build children robots out of component parts to see how well they move, doing all of the hard work of robot evolution without any simulation compromises. Once the evaluation is complete, the child robots are disassembled (manually, for now) by removing the hot glue, and the components are returned to the queue to make a new robot. Meanwhile, in software, the successful “elite” designs (the ones that were able to move the farthest in the least amount of time) are carried on to the next generation unchanged. The system also mutates or crossbreeds the elites to create the rest of the next generation. The basic idea behind evolutionary robotics is to build a whole bunch of simple robots, test them in some way, and then take a few of the most promising robots and use them in the design of the following generation. A UR5 arm is the “mother robot” which constructs the “child robot” out of a few standardized parts, including active cubes with one rotating face and smaller passive cubes made out of wood. The mother robot hot-glues active and passive cubes together and then transports them to a testing area, where they’re wirelessly activated and an overhead camera watches them wiggle around. Overall, “a fitness increase of more than 40 percent over 10 generations was observed in all experiments,” which is pretty good, but the impressive part is that it’s all physical. The robots have all been built and tested, so you know the elite designs really are elite, and will behave well in whatever application you come up with for a weird little robot made out of some cubes.

SLAM DUNK ON IMPROVEMENTS

J

ohn Leonard’s group in the MIT Department of Mechanical Engineering specializes in SLAM (simultaneous localization and mapping), which is the technique whereby mobile autonomous robots map their environments and determine their locations. At the recent Robotics Science and Systems Conference, members of Leonard’s group presented a new paper demonstrating how SLAM can be used to improve object-recognition systems, which will be a vital component of future robots that have to manipulate the objects around them in arbitrary ways. The system uses SLAM information to augment existing object-recognition algorithms. Its performance should thus continue to improve as computer-vision researchers develop better recognition software, and roboticists develop better SLAM software. Despite working with existing SLAM and object-recognition algorithms, however, and despite using only the output of an ordinary video camera, the system’s performance is already comparable to that of special-purpose robotic object-recognition systems that factor in depth measurements as well as visual information.

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Did You Know ...

ROBOT SURGERY IS A HIT AND MIS

I

n the largest multi-institutional study to date, patients diagnosed with bladder cancer and treated with robot-assisted surgery experienced similar results to those who underwent a traditional open operation, according to research led by scientists at Roswell Park Cancer Institute (RPCI). The study results were recently published in the journal of the European Association of Urology. “We found that robot-assisted radical cystectomy, an advanced surgical procedure used to treat bladder cancer that has spread to the bladder wall or recurred, despite local treatment in the bladder, provides similar early oncological outcomes while reducing operative blood loss,” says Khurshid Guru, MD, Director of Robotic Surgery in the Department of Urology at RPCI. The study is a retrospective review of long-term patient outcomes for cystectomies that currently populate the International Robotic Cystectomy Consortium, which represents 11 institutions in six countries. Data from 702 patients with clinically localized bladder cancer from 2003 to date were analyzed for five year recurrence-free survival (67%), cancer-specific survival (75%), and overall survival (50%). When compared with traditional open surgery, patients treated with robotassisted surgery experienced similar long-term survival outcomes. Robot-assisted surgery is a type of minimally invasive surgery (MIS) that uses surgical robotic equipment that imitates surgical movements. MIS procedures allow surgeons to operate through small ports rather than large incisions. For patients, robot-assisted surgery results in possible shorter recovery times and minimal blood loss.

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Post comments on this section and find any associated files and/or downloads at www. servomagazine.com/index.php /magazine/article/september2015 _CombatZone.

Featured This Month: 28 BUILD REPORT: A New Weapon for Spanky by Mike Jeffries

31 Parts is Parts: HobbyKing CAR-45A Brushless Reversible Speed Controller by Pete Smith

32 Cartoon 33 BUILD REPORT: Viper Fighter Mark-2a by Chris Olin

36 BUILD REPORT: Splatter: The Evolution of a Combat Robot by Matthew Vasquez

38 EVENT REPORT: Clash of the Bots 2015 by Pete Smith

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BUILD REPORT: A New Weapon for Spanky ● by Mike Jeffries

T

here are risks inherent in designing a robot to accommodate a modular weapon setup. Often, each weapon isn’t as good as it could be if the bot was designed around a specific weapon instead of a range of them. In this case, the real risk is that you’ll keep coming up with new interesting modules that you’ll then feel compelled to build. Spanky was originally conceived as an overhead thwackbot with swappable heads. It was the desire to allow Spanky to compete in the Sportsman class at Motorama that led to the creation of a pair of powered attachments — a circular saw and a chainsaw.These were developed during the initial design of the robot and as such the heaviest attachment put the robot very close to the 30 lb weight limit. That was good enough for a

while, but after Motorama earlier this year, my fiancé (and the driver of Spanky) decided that she wanted a new weapon. After some initial concept sketching, we moved the design into CAD and sorted out the basic geometry of the system. With the geometry figured out and a weapon motor selected (the Magnum775 from www.robot power.com), the next stage of the

The original concept with no real attention paid to weight. The first priority was dialing in the geometry to get the bite profile we wanted.

The finalized weapon design. It’s not underweight yet, but it’s close enough. Drilling the main attachment point for the assembly.

After pressing the tubing into the mount plate, it’s ready for welding.

The assembled front support bracket. Acme nut after being ground down.

design involved many hours of finding places in the mechanism where weight could be removed. This process resulted in a fairly skeletal appearance to the whole structure, while still maintaining a decent amount of strength and protection in key areas. While not light enough to make weight as-is, the design was finalized at this point and drawings were prepared for fabrication. With the knowledge that the bot wouldn’t be underweight as it was designed, a few changes were made to the main structure of Spanky. Among the changes were switching from 2” wide to 1.5” wide Colson wheels (along with the removal of some support ribs and the cutting of treads into the wheels), the removal of some excess chunks of steel in the main chassis design, and a switch from steel top and bottom armor to titanium of the same thickness. At this point, the steel part drawings were sent to www.discountsteel.com for laser

One of the shafts prior to the second weld pass.

cutting. The 7075 aluminum and 6AL4V titanium were also ordered from www.midweststeelsupply.com and www.amxinc.com, respectively. The titanium and aluminum parts were waterjet cut locally a few weeks after the stock was delivered. Once everything was on-hand, it was time for the on-site fabrication and assembly to begin. The weapon uses some 2x1” rectangular tubing as the mounting adapter. The tubing is cut to length, drilled with the mount pattern, then pressed and welded to the steel mount plate. The next step of construction was the modification of the acme nut. One corner of the nut had to be shaved down to ensure that it would clear the mounting adapter when installed. This modification was quickly handled with

an angle grinder and a 24 grit sanding wheel. The next step in the modification process was the welding of the 1/2” rods to the nut. As part of this process, the sides of the nut were slightly counter-bored on a mill to allow the shafts to slip partially into the profile of the nut. The point of this was to ensure a more robust joint between the components. Each shaft had two passes around the entire perimeter with a tig welder. The first pass joined the shaft to the nut with minimal filler material. The second pass included the use of filler material to further reinforce the connection. This resulted in some warping, but not enough to cause issues with the overall assembly. Following this, the front support bracket was assembled. This piece consists of two bushings, a 7075 aluminum plate, and two sections of large size nutstrip. This assembly slides over the motor shaft and leadscrew before being sandwiched between the two side plates. With the core components all SERVO 09.2015

29

Checking to see what does and does not line up properly.

The fully assembled weapon without the roller chain installed.

The Magnum775 stayed cool during testing and appears to be well-suited to the weapon.

Adding a hard stop to the end of the screw.

finished, it was time for a test fit. This check showed that the bushing on the front support plate needed to be shaved down to accommodate the tolerance stack-up across the assembly. After a few passes with an endmill, the bushing was the proper thickness to allow everything to spin smoothly, and the final mechanical assembly was able to be completed quickly. Running the chain was a bit difficult due to the close quarters, but after some effort it was fully routed. The whole assembly was then

installed and hooked up for testing. Initial tests consisted of cycling the weapon several times listening for rough spots and watching for binding. With no obvious issues, testing moved to the street where the weapon was cycled multiple times while driving the bot around and flipping it over repeatedly. At the completion of these tests, I noticed that the lead screw had shifted position. Some follow-up testing showed that the issue resulted from the weapon reaching a travel limit while the motor was still getting power. The Magnum775 continued to

The top view of the robot with the weapon motor hidden below the chassis.

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SERVO 09.2015

The quick connect setup allows easy weapon changes on Spanky.

A spring pin was added to positively attach the sprocket to the screw.

try to drive the screw, and the result was the sprocket spinning on the threaded shaft and causing the shaft to move. The first part of addressing the issue was the addition of a welded washer to the end of the screw to prevent the nut from being driven past the end of the screw. This at least allowed for further testing and final weight reductions, while the second part of the solution shipped. With the screw pinned and working as intended, all that remained for the weapon were a few photos of the completed system. SV When inverted, the weapon motor is fairly exposed above the robot. However, it can quickly flip over to minimize the chances of damage.

PARTS IS PARTS: HobbyKing CAR-45A Brushless Reversible Speed Controller ● by Pete Smith

I

have been using HobbyKing by a single plug. The power (www.hobbyking.com) brushless switch can be removed and speed controllers in my combat the pins shorted in the ON robots since 2007, when I used one in position as shown in Figure Surgical Strike to take first place in the 2. This is just added weight 12 lb weight class at RoboGames. I and bulk, and a possible then used a modified 35A reversible failure point if the switch was car type ESC (electronic speed shocked into the off position controller) to control the beater bar in in combat. my Beetleweight Weta kits. I then shortened the A bad batch of these ESCs (two other power and motor leads out of three smoked on power-up) and added connectors to prompted me to seek out an match those I use in Weta. alternative type of ESC as a back-up to The changes reduced the my dwindling supply of the older weight to 1.8 oz (51 g). design. I chose to try out the CARNext, I programmed the 45A (Figure 1) also from HobbyKing. ESC using the programming At the time of writing this article, card (Figure 3). It’s easy to the speed controller cost $20.95; its use and you can quickly try HKProg-card programming card was out the different settings to an additional $6.81; and both were find what works best in your available from their USA East bot. warehouse which reduced shipping Once I had it performing costs and time. as desired, I also shortened The existing ESC as used weighed the signal leads by cutting 1.5 oz (42.5 g) and the new one the connector off and weighs 2.2 oz (63 g) as delivered. soldering the leads directly to That weight includes a small fan, an external on/off switch, and excessively long power and signal wires. The fan was removed as they are easily damaged, relatively bulky, and not usually required in our application where run times are relatively short. It’s only held in place with four small screws and connected Figure 3. Programming the ESC.

Figure 1. CAR-45A ESC.

Figure 2. Shorted power-on pins.

Figure 4. Soldered signal leads.

SERVO 09.2015

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Figure 5. Completed ESC. Figure 6. Testing in Weta.

the pins, making sure to connect them correctly (Figure 4). The fully modified ESC can be seen in Figure 5. It’s a little bulkier than the old one. Those big capacitors add most of that, but since they add protection to the electronics it’s worth the space. The larger heatsink and higher amperage rating should also add a little more safety margin in use.

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Finally, I tested the new ESC in Weta (Figure 6), powering the beater bar with a 5,500 kv 2848 motor, giving it a full three minutes’ run with several stops and restarts in forward and reverse. It performed well. At the end of the test, it was only slightly warm. The ESC works well at 3S and should make a useful weapon ESC for Beetleweights.

Next month, I will modify and test the similar HobbyKing HK-SENS-35A. I will try both it and the CAR-45A for use in drive applications, and both with 4S and 5S LiPos (they are nominally 3S ESCs) to see if they cope with the higher voltage (many ESCs can). SV

BUILD REPORT: Viper Fighter Mark-2a ● by Chris Olin

A

fter back to back crushing defeats by Pretzel Robotics' Vile Ant and Low Blow, it became clear I needed a better Antweight robot. My previous Antweight, Viper Fighter MK-1 was built using a modified base plate from FingerTech Robotics. An original Viper kit was used as a top plate/wedge with a very thin polycarbonate bottom cover, Silver Sparks 1:35 motors, FingerTech tinyESCs (electronic speed controllers), and a custom lifter arm powered by a high torque servo. The thin aluminum Viper base plate was barely adequate and the servo powering the lift was far too exposed. For my next servo lifter, I needed a stronger chassis and better protection for the servo. The new Combat Viper kit from FingerTech Robotics (see Michael Jefferies review in SERVO May 2015) seemed to provide for both of those requirements. For Viper Fighter MK-2a, I decided to use the Combat Viper kit with lifter, but make a few upgrades: 1. Replace the stock HXT 12 kg servo with a XQ Power 4220 11V servo. 2. Replace the 9V Duracell battery with a 11.1V Thunder Power Pro Lite 250 mAh 11.1V LiPoly Pack. 3. Shock-mount the servo. 4. Reuse the soldered wire harness from the previous robot. 5. Replace #6-32 x 1/2 pivot screws Battery Weight Battery Voltage Servo Speed Servo Stall Torque Drive Speed (RPM) Drive Speed (feet/sec) Drive Speed (MPH)

Viper Fighter MK-1 and Vile Ant at HORD 2014. Viper Fighter MK-1.

FingerTech Robotics Combat Viper Chassis kit.

with partially threaded screws for better pivot action. 6. Cut off excess motor shaft.

Battery Upgrade and Wire Harness The base Combat Viper kit came with complete and well-worded instructions. It assembled quickly with no problems. The only real change I

Stock

Upgraded

1.60 oz (Duracell) 9V (Duracell) 60° in 0.09 sec (HXT 12 kg) 250 oz-in (HXT 12 kg) 405 3.98 2.71

0.90 oz (Pro Lite LiPo) 11.1V (Pro Lite LiPo) 60° in 0.11 sec (XQP-4220) 286 oz-in (XQP-4220) 499 4.90 3.34

Viper Fighter MK-2 wire harness and battery.

made to it was to reuse the wiring harness from my previous robot instead of the wiring kit and power switch that came with it. My existing main power harness consists of one female JST connector and three JST male connectors soldered together. The three male connectors attach to the female connectors added to the tinyESCs and the servo. The female connector goes directly to the 11.1V battery. Main power is activated and deactivated by connecting and disconnecting the battery connection. The servo and ESCs connect to the receiver in the same fashion as the standard kit. This arrangement is SERVO 09.2015

33

FingerTech Robotics Combat Viper lifter kit.

Upgraded pivot axes.

Lifter kit complete with pivot screws trimed.

Servo with grommets and eyelets installed.

Servo, mounting grommets, and eyelets.

slightly lighter and more compact than the standard wiring, but much more work.

Servo and Battery Upgrade Using the XQ Power 11V servo instead of the stock HXT servo gives me more torque on the arm, but less speed. More importantly, it allows me to run the whole robot using a 11.1V LiPo battery instead of 9V disposables (without the addition of a regulator). This gives my drive a theoretical speed increase of about 22%. Also, the 11.1V LiPo battery holds more power and weighs less.

Servo Shock Mounting The Viper lift kit instructions

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specify mounting the servo directly to the mounting bracket with #4-40s. I have been using servo lifter weapons in Ant and Beetleweight robots for many years, and my experience has been hard-mounting the servos increases the likelihood of the mounting ears (flanges) on the servo case breaking under the severe shock loads that are common in the combat arena. I prefer to use the rubber grommets and brass eyelets included with most servos to help reduce the shock load on the mounting ears. The grommets fit into the mounting ears and protect them from vibration and shock. The eyelets press into the grommets and prevent over-tightening of the mounting screw. The eyelets included with most servos are designed for 2.5 mm screws which are slightly larger than #4-40 screws which the FingerTech servo mounts are designed for. In order to use them, I had to drill out the #4-40 threads on the servo mounting bracket, then use four M2.5 x 0.45 x 20 mm LG screws and matching nuts to secure the servo to the brackets. This also shifted the

Cutting off excess motor shaft with Dremel.

position of the servo slightly, causing the arm to not line up with the slot in the top plate. I had to cut away a little material in order for the arm to work properly.

Arm Pivot Step 1 in the lift kit instructions states: "Attach the Mini Nutstrip pieces [to lifter arms] using two 6-32 x 1/2 screws with threadlock liquid applied to the threads. Leave just loose enough that they spin freely." This is a quick and dirty way to create a pivot axis. The threadlock liquid (similar to super glue) will keep the screw in place, but would make quick repairs in the pits difficult. This also means the polycarbonate arms are rotating on a threaded shaft which could dig into the plastic and cause the arm to not operate smoothly. Instead, I used a pair of partially threaded socket head cap screws. The non-threaded portion of the screws created a smooth bearing surface for the arms to rotate around, and

Viper Fighter MK-2 vs. Super Orange Glow at Clash of the Bots 2015.

Combat Report Viper Fighter MK-2 complete.

allowed the screw to be screwed tight to the nutstrip (thus removing the need for threadlock). The screws had about one inch of threads; I cut the extra length of the screws off with a Dremel tool.

Final Touches The motor shafts are about an inch longer than they need to be for this application; that extra length could make the shaft more vulnerable to a spinning weapon, so I trimmed the shafts with my Dremel tool to be flush with the wheel hub. The base plate still had open holes where the spinner weapon kit power key would go, and a few gaps in the wheel well. After a few fights, the arena can become littered with dust and debris which I would rather not have inside my robot. So, I covered the holes and gaps with Gorilla tape (similar to duck tape but stronger and hairier). With all modifications done and the robot completely assembled, it weighed in at 15.50 oz. I tested the robot on a concrete floor and found it to be quick and responsive. It drove very straight for a two-wheeled robot (which tend to pull to one side), and the flipper arm had enough power to pick up a 1 lb object. However, the shape of the steel "scoop" that came with the lifter kit made it hard to get under my test dummy to get a good flip in. The robot was able to self-right very easily from any orientation.

Viper Fighter MK-2a's first trial by fire was at Clash of the Bots 2015. The first fight was against Super Orange Glow by Team Browns Mountain Lab from Greeneville, TN. This robot featured a small vertical spinning disk and a four-wheel drive system. Viper dominated this match, consistently out-running and out-maneuvering the much slower Super Orange Glow. Viper was able to get in several lifts and a few flips, plus also push the other bot to the wall a few times. In contrast, Super Orange Glow's disk did only superficial damage. Viper Fighter's second opponent was Klazo by Near Chaos Robotics from Norcross, GA. Klazo featured a powerful spinning drum weapon and a two-wheel drive system. At the start of the match, Viper charged Klazo, met her head on, and tried to get a flip in, but did not get the scoop far enough under Klazo for an effective lift. Klazo quickly came back and clipped Viper's left side with her drum and easily took off a wheel. Viper tried to stay in the fight by "crabwalking" across the arena and got in one partial lift before Klazo took off the other wheel and ended the match in one minute. Total damage to Viper: two broken motor shafts; one lifter arm was bent and cracked at the cross bar joint; the right front corner of the chassis was bent upward; and there were several deep gouges in the front polycarbonate plate.

Viper Fighter MK-2 vs. Super Orange Glow at Clash of the Bots 2015.

Viper Fighter MK-2 after fight with Klazo at Clash of the Bots 2015.

Klazo went on to take 2nd place, losing only to teammate, Algos. I chose to forfeit Viper's next match so I could focus on repairing my other robot.

Conclusions Upgrading the drive to 11.1V dramatically improves driving performance and helps get the flipper in position. The XQP-4220 servo at 11.1V performs very close to the HXT 12 kg at 9V. However, it should be noted the HXT 12 kg is only rated for 7.4V, whereas the XQP-4220 is rated for 11.1V (which should make the XQP-4220 more reliable). Viper took several major hits from Klazo's drum but suffered no internal damage. The servo was very well protected. Over all, Viper MK-2a preformed much better than Viper MK-1. For the next version (MK-2b), I would like to protect the motor shafts from side hits and modify the lifter scoop and arm in order to get under the opponent better. SV SERVO 09.2015

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BUILD REPORT: Splatter: The Evolution of a Combat Robot ● by Matthew Vasquez

F

or nearly my whole life, I have been involved in the world of combat robots. Although my first Antweight fight was at the age of six, I have only been seriously competing in the Insect classes for a few years. After working on robots in the larger classes for so long, I wanted to try out the smaller ones. I liked the more relaxed atmosphere, and that events were held more frequently. Splatter was my first Beetleweight combat robot. I originally created it to compete in the 2013 SoCal Mini Maker Faire “Robot Throwdown” competition. I decided on competing with a Beetleweight only a few days before the competition, so I thought I would build a simple under-cutter, using only leftover parts we had in our garage. The robot consisted of a seven inch saw-blade, direct driven to a 35

Splatter before the Mini Maker Faire.

Splatter version 3.

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mm brushless motor. The drive had four 50:1 Copal motors I found, hotglued to a 1/8” aluminum base. The robot was not my best work, but was enough to enter into the competition. I went into my first round against Squirty (a full body spinner), not knowing how my bot would hold up. Luckily, Squirty was not able to spin up to speed, so I was able to easily win the match, destroying one of my own drive motors in the process. Next, I fought the drum spinner called Jason’s Revenge. I really did not think I had a chance in this fight, but my undercutting saw-blade was low enough that the opponent’s drum hovered right over it, not able to catch on. I pushed him into the wall, causing his drum to hit the top of my robot launching him out of the arena, giving me a first place. I knew I would never get this lucky again with the setup I had on Splatter, so I made some changes. I replaced the hot glue mounted Copals with four FingerTech 33.3:1 Silver Spark motors, and FingerTech Lbracket motor mounts. The robot was still very successful, taking a second place at another Robot Throwdown event, and a first place at the Smashbotz 2014 Backyard Brawl. I was happy with the performance of the robot, although there were still more improvements I wanted to make. The robot had plenty of pushing power with the Silver Sparks, but the motors were not holding up in combat with the current setup. So, I decided to try out the Kitbots 1,000 RPM motors

with my own custom mounts. The next event was another Robot Throwdown competition with five Beetleweights entered. My first match was against Jason’s Revenge. I was doing pretty well getting behind him, cutting up his wheels in the beginning of the match. Eventually, he escaped, going straight at me weapon to weapon. The hit disabled my horizontal spinner, destroying the weapon motor. Jason’s Revenge went for one final hit, throwing me out of the arena. The drive was okay, but my weapon assembly was destroyed, forcing me to replace it with a Gorilla tape attached titanium wedge. Although I had no weapon, I managed to win all of the rest of my matches by sliding underneath my opponents, and easily dragging them into the push-out. I was very surprised by the success of the simple wedge, so I tried to think of a way to integrate it into a creative, yet destructive design. I eventually came to the conclusion that an overhead chop saw design was what I was looking for. I had seen some other successful overhead saw designs like SOB or Gloomy, but I didn’t want to build the traditional dust-pan design. I wanted to keep the four-wheeled drive platform I had done so well with. I drew up some simple designs on Google SketchUp and immediately started building for the next Sonoma Ant Wars competition that would take place the next week. I cut off the front of the 1/8” aluminum base where the original weapon motor was

Splatter ready for Sonoma Ant Wars 2014.

mounted and added 1/4” UHMW wall. I then cut out the arm from another 1/4” piece of UHMW. The saw would be powered by the same 35 mm NTM motor the original disk was. The arm was powered by a B62 gear motor. The robot again was not the best build in the world, but was enough to compete with. I went into my first match against the most feared bot in the competition: the deadly egg-beater of the Fighting 84th. We went straight at each other, where he was able to launch Splatter into the ceiling of the arena. The Fighting 84th landed upside-down where Splatter landed right next to it on its wheels. I brought down the saw going straight through the carbon fiber base of the Fighting 84th. I managed to take a bite out of his weapon motor, but he came back ripping off the saw blade and knocking out all four of my drive motors. Although Splatter was completely destroyed, it managed to win its next four fights by using a makeshift lifter attachment, but then lost again in the finals to the Fighting 84th. By the end of the competition, there was nothing left of Splatter. This meant I had to give Splatter a complete overhaul. I ditched the old chassis, and made a new one using all FingerTech titanium for a base and top plate instead of aluminum, and used 1/4" UHMW walls. I was able to salvage the arm and lifter motor. Another change I made was using the new Team Tiki gear motors for drive, and doubled up the Lite Flite wheels

The Fighting 84th’s weapon motor after fighting Splatter.

to protect the motor shaft from impacts. The robot did decently at the SoCal Maker Con, earning another second place losing to Jason’s Revenge, but was not able to pin anyone and bring the saw down with the current wedge attachment. So, instead of a standard wedge, I replaced it with a long flat 1 mm titanium spatula. At the next Smashbotz event, in my first match I went up against a standard four-wheeled wedge bot from UCLA. I was able to scoop it up and bring the saw down, easily cutting through the 1/8” Lexan lid, chopping one of the drive motors nearly in half. Unfortunately, once again when I reached the finals, I lost brutally to the drum spinner of Jason’s Revenge. So, for the next event (RoboGames 2015), I made some changes to Splatter. I switched out the titanium spatula with 1/4" UHMW to prevent it from bending, and added two 0.5 mm titanium arms to keep opposing robots from escaping. Splatter was in peak condition. Of course, my first match at RoboGames was going to be once again against my brother’s bot, Jason’s Revenge. Luckily, I was able to box-rush Jason’s Revenge and quickly bring the saw down. The saw went straight through the top plate, cutting through his weapon speed controller. This disabled his BEC, knocking out the robot.

The cut Splatter made in the Fighting 84th’s base plate.

The Team Tiki gear motor.

Splatter did well in the competition but had some weak points in the frame, and simply needed more room for weight. Maintaining such a complicated robot can be challenging, but I plan to stick with the current design and to keep perfecting it. My goal is to learn from my previous mistakes, and to hopefully take the Gold at next year’s RoboGames. The one thing I took away from the experience of working on Splatter is that you should never shy away from trying something crazy or untraditional in the world of combat robots. It’s all about being creative. SV

Splatter’s new design for Sonoma Ant Wars 2015.

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EVENT REPORT: Clash of the Bots 2015 ● by Pete Smith

C

arolina Combat Robots (www.carolinacombat.com) and the Schiele Museum in Gastonia, NC (www.schiele museum.org) held their sixth Clash of the Bots event on June 6, 2015. The event has been growing, and a good turnout of bots and a really first class venue makes it one of the best one-day events on the East coast. The museum provided a large space for the event, and a free lunch, soft drinks, snacks, and coffee for competitors. There was plenty of space for the pits, the Insect class arena, a 75” touchscreen TV for displaying the brackets (Figure 1), the Bot Hockey arena (Figure 2), an outdoor area for drilling and grinding (Figure 3), and even space for me to set up my photo light tent (Figure 4). Carolina Combat (Chuck Butler and his family) had set up the arenas the day before and the venue opened up for competitors at 8.00 am. The bots went through safety and fights got started around 10.30 am. Four different classes of bots were competing: the 150 g Fairyweights; 1 lb Antweights; 3 lb Beetleweights; and finally, the 15 lb Bot Hockey. Teams came in from as far as the West and Gulf coasts. The fights of the various weight classes were mixed up throughout the day, but for simplicity’s sake I’ll cover them one class at a time starting with the Fairyweights. There were only three entries this year, so they fought round robin style, with each robot fighting each of the other’s, and the bot with the best record winning. The three bots were Pissed off Unicorn (Figure 5); Krabby (Figure 6); and

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Figure 1. Arena and brackets display.

Figure 2. Bot Hockey arena.

Mini Stumpy (sorry no picture, but it was a 2WD wedge). Unicorn’s spinning weapon dominated the class, tearing Mini Stumpy apart in their match. However, Unicorn’s drive issues meant that all three bots had the same record after the initial round of fights. The winner was decided in a rumble where all three bots took part. At the start, Unicorn again dominated

but with the rumble lasting five minutes rather than the normal (for this event at least) two minutes, his batteries could not last and the judge’s decision went to the aggressive and still mobile Mini Stumpy. Eleven 1 lb Antweights competed and fought full double elimination brackets. In double elimination, each

Figure 3. Area for drilling and grinding.

bot has to lose twice before it is eliminated. There was a wide variety of designs: wedges like Short Stop (Figure 7) and Affluenza (Figure 8); flippers like Viper Fighter (Figure 9); and kinetic energy bots like Gallade (Figure 10); Klazo (Figure 11); last year’s champion Algos; the latest version of Saifu (Figure 12); and one

Figure 5. Fairyweight — Pissed Off Unicorn.

Figure 4. Photo light tent.

with an Erector Set vibe called Super Orange Glow (Figure 13). There was even a Twackbot made mostly of plumbing parts called Satan’s Segway (Figure 14). There was also an interesting new design — Praise Helix! — which combined a beater bar with a built-in motor with a long titanium clad

wedge. Sadly, due to issues with the right angled gears in the drivetrain, it did not compete. EXP was also included in the field of competitors. KE bots dominated from the start, with Klazo beating Short Stop in a judge’s decision, Saifu swiftly knocking out Satan’s Segway, and Algos (Figure 16) dominating

Figure 6. Fairyweight — Krabby. Figure 7. Antweight — Short Stop.

Figure 8. Antweight — Affluenza.

Figure 9. Antweight — Viper Fighter.

Figure 10. Antweight — Gallade.

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Figure 13. Antweight — Super Orange Glow. Figure 11. Antweight — Klazo. Figure 12. Antweight — Saifu.

Figure 14. Antweight — Satan’s Segway.

Figure 15. Antweight — Praise Helix!

Figure 16. Antweight — Algos.

Figure 18. Beetleweight — Kräftor.

Figure 17. Pulling teeth on Grande Tambor.

Affluenza. Only Viper Fighter and EXP (go to YouTube to see EXP in action) put up appreciable resistance. Viper Fighter had better speed and was tough enough to beat Super

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Orange Glow before getting outwedged by Affluenza. EXP had a good run in the loser’s brackets with toughness and a bit of luck (it won its fight against Saifu when the latter

Figure 19. Beetleweight — RMR with blade.

forgot to use a freshly charged battery) before running out of that luck, losing to Klazo. Teammates (Mike Jeffries with Algos and his fiancée, Julie with

Figure 21. Beetleweight — Project Terminus. Figure 20. Beetleweight — RMR with drum.

Figure 22. Beetleweight — Revenge of Dr. Super Brain.

Figure 23. Beetleweight — Unknown Avenger.

Klazo) faced off against each other in the winner’s bracket semi-finals. These two bots have fought before — usually with Algos winning — and it looked like that would happen again with Algos getting most of the good hits in. Then, Klazo got a bite on one of the exposed wheels on Algos, ripped it right off, and followed that up with the biggest hit of the match to get a

Results. Fairyweights Fairyweights Fairyweights

1st Place 2nd Place 3rd Place

Antweights Antweights Antweights

1st Place 2nd Place 3rd Place

Beetleweights Beetleweights Beetleweights

1st Place 2nd Place 3rd Place

Bot Hockey Bot Hockey Bot Hockey

1st Place 2nd Place 3rd Place

Figure 24. Grande Tambor vs. Revenge of Dr. Super Brain.

fairly easy judge’s decision. Algos dropped down to the loser’s brackets but made quick work of EXP, throwing it around the arena and removing one wheel. That left the teammates back in the finals, but Klazo could not repeat its earlier success and first place went to Algos. Last year’s runner-up, Grande Tambor was probably the favorite to win the Beetleweights this year. Its builder, Jeremy Butler did a last Mini Stumpy minute tune-up replacing Krabby its worn blunt teeth Pissed Off Unicorn (Figure 17) with nice Algos shiny sharp ones to help Klazo make that come true. EXP There were eight other Beetles trying to Grande Tambor spoil that plan. There Trilobite was a crusher Kraftör BOB (Figure 18); a clever Team Ice configurable O-ring Team Scotch Pies tracked spinner RMR Team Pneusance that could have an

Figure 25. Beetleweight — Trilobite after fighting Grande Tambor.

overhead blade (Figure 19) or be rebuilt as a drumbot (Figure 20); my wedge/brick Trilobite; another overhead spinner with wide UHMW skirts, Project Terminus (Figure 21); flippers The Revenge of Dr. Super Brain (Figure 22) and Unknown Avenger (Figure 23); a Nightmare style vertical sawblade spinner BOB, Big Old Blade (sadly, no picture); and a wedge called Business Casualty. Grande Tambor quickly ran through the field, with its new sharp teeth easily defeating Business Casualty and Trilobite, and wrecking the flipper mechanism of The Revenge of Dr. Super Brain, leaving him unable to selfright and immobile (Figure 24). BOB had a slow start narrowly beating Unknown Avenger, but with the weapon working and full mobility, it tore apart Project Terminus. However, it proved no match for Grande Tambor. After being treated SERVO 09.2015

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Figure 27. Hockey bot — Autodestruct.

proved more effective than the overhead spinner version, but Trilobite’s wedge got under the drum most of the time. Something then failed and RMR lost power to its drive and weapon, and was counted out. In the fight against Project Terminus, its opponent’s blade failed early and Trilobite spent the rest of the fight pushing it around for an easy judge’s decision. The next fight against The Revenge of Dr. Super Brain was a lot tougher. The flipper had lost its flip but it was still a fast well-driven wedge. Trilobite only got the win by a narrow judge’s decision. The loser’s brackets semifinal was Trilobite versus BOB. This was an exciting fight with Trilobite harrying

Figure 26. Hockey bot — Ply-able.

like a chew toy and then losing a drive wheel, it tapped out leaving Grande Tambor with a place in the finals. Trilobite had a longer run to the finals in the loser’s brackets. First, it fought the drum version of RMR. This

Figure 28. Bot Hockey.

Personal CNC Mills Shown here with optional stand and accessories.

Shown below is an articulated humanoid robot leg, built by researchers at the Drexel Autonomous System Lab (DASL) with a Tormach PCNC 1100 milling machine. DASL researcher Roy Gross estimates that somewhere between 300 and 400 components for “HUBO+” has been machined on their PCNC 1100.

PCNC 1100 Series 3 starting at:

$8480 (plus shipping)

www.tormach.com/servo

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BOB and BOB getting in some big hits, until BOB lost first one drive wheel then the other. The final then was Grande Tambor versus Trilobite. We tried a different wedge attachment and had more success — especially when running upside down. It was a close match, with perhaps Trilobite having the edge until we lost drive on one wheel. Grande Tambor took full advantage and got in several quick hits, leaving Trilobite hanging on the edge of the area. We tapped out to avoid any more damage (Figure 25), making Grande Tambor this year’s champion. The Bot Hockey at Clash of the Bots has slowly grown over the years, and this was the first year where we had enough hockey bots to form three full teams without borrowing bots from other teams. One of the newcomers was Ply-able (Figure 26), made largely from wood (though it looks more like clear pine than ply!); and Autodestruct (Figure 27) which had competed as a 12 lb combat robot about 10 years ago. The Bot Hockey was played round robin and was great fun (Figure 28) for both competitors and the audience. It made a few more converts since some builders will be adding to the numbers next year. The matches were fairly close — especially the one between Team Pneusance and Team Scotch Pies which saw numerous lead changes before Scotch Pies grabbed the victory at the last minute. Team Ice, however, won both their matches so took first place. Videos of all the fights can be found on Mike Jeffries’ YouTube channel at www.youtube.com/channel/ UCpNz2kKih2JTe3GKcpsGEbg. A quick presentation of the prizes (supplied by sponsors: FingerTech Robotics at www.fingertech robotics.com; Kitbots at www.kitbots.com; and SERVO Magazine at www.servo magazine.com) wound up the event in the late afternoon. SV

BooBits:

Three Ghoulish littleBits Projects By Dave Prochnow

We've all learned about littleBits (littlebits.cc) — the magneticallyattractive building modules — from past issues of SERVO Magazine (see November 2014, December 2014, February 2015, and June 2015). Now, it's time to put them to real work — for Halloween 2015!

A

t first glimpse, electronic “bits” that snap together under the power of magnets might not seem suitable for enduring the rigorous candygrabbing armies that invade a house during All Hallows’ Eve. However, with some careful planning (see Figure 1) and robust building techniques, you can assemble these three treats in one evening. They’re perfect for adding some excitement to your candy bowl.

Boo2U It’s time to add some twitch to your tricks. In this project, we’re going to animate a simple hand puppet. The puppet will come to “life” when children come near it. This effect is a great demonstration of four very basic littleBits modules. First of all, we need the ever-present power module (p1). This little beauty gives life to all of our littleBits creations. Just plug a 9V battery into the barrel jack found on the p1 module, and you have a sweet portable power supply — complete with an ON/OFF switch.

Figure 1. Tools of the trick trade for Halloween.

Once we’re juiced with the power module, we add a sound trigger (i20) module. This is an input module that is color-coded pink (or fuchsia, if you prefer).The sound trigger works by “listening” to sound levels which then transmits an ON signal to other connected modules when it “hears” something. The sensitivity of this module’s hearing is controlled by a small trimmer potentiometer (pot). When the sound trigger hears a group of children speaking nearby, it triggers our third module: timeout (i17). This is another input module. Rather than listening, this module is a “thinker.” The timeout module likes to think about turning ON and turning OFF during a specific time interval. Another trimmer pot controls the duration of this module’s thinking period. A separate toggle switch sets whether the timeout is ON then OFF, or OFF then ON. Regardless of the switch’s state, its thinking period will determine how long our fourth — and final — module remains active. Our hand puppet is controlled by a small DC motor SERVO 09.2015

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Go to www.servomagazine.com/index.php/magazine/article/september2015_Prochnow to comment on this article.

Figure 2. Four littleBits modules are used for Boo2U.

module (o5). The motor is an output module and is colorcoded green. Inside our hand puppet, this motor is either ON or OFF. While there is a switch on the module that can control the direction of the motor’s shaft rotation (e.g., LEFT or RIGHT), all we care about is using the ON signal from the timeout module to make the motor turn ON. Curiously, the DC motor module comes with a small attachment called motorMate (a10). This is an accessory for the motor that slips over the shaft and converts it into a LEGO building element cross-shaped axle receptacle. By using this accessory, we can easily incorporate a LEGO “arm” inside the puppet which will cause the puppet to move when someone yells into our sound trigger module. Figure 2 shows the complete littleBits project

Figure 3. Waiting for a victim, err, Halloween guest to speak up.

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assembled and ready for insertion inside our hand puppet. You must calibrate the listening sensitivity and the thinking timer function prior to insertion into the puppet. Don’t make the motor movement lengthy nor excessively move the entire puppet. I inserted the LEGO arm attached to the DC motor module inside one of the puppet’s arms. During operation, Boo2U will slowly move one hand for every loud noise. Figures 3 and 4 show the amount of hand movement with Boo2U.

Coffin Cruiser Every robot builder loves using LEGO building elements in a project. Using the LEGO ecosystem is an easy way to get a robot up and moving in a short amount of time. Our Coffin Cruiser is no different. Again, we are going to use only four littleBits modules, but the results are going to be anything but little! In this case, we are going to make a remote controlled DC motor powered spook-mobile out of a stock LEGO Hot Rod building kit (Technic Kit #42022; available at LEGO, Amazon, Target, Sears, and eBay). Plus, to make this project even better, you’ll be able to use your TV remote control (any and every TV remote control should work with this

Figure 4. Just enough movement to catch the eye.

project) to drive the coffin around. You can see the layout of the four littleBits modules in Figure 5. There are four modules in the Coffin Cruiser project: power; remote trigger; long LED; and DC motor and motorMate. While two members of this cast of characters are already familiar to us, two others merit a brief introduction. The remote trigger (i7) is a pink colorcoded input module. This module is primarily responsible for all of the magic that happens with the Coffin Cruiser. The remote trigger enables you to use any TV Figure 5. Coffin remote control for turning the DC motor Cruiser is a ON and OFF. Just press any button on great RC bot, your TV remote and the DC motor turns using only four ON. Release the button, and the DC littleBits modules. motor turns OFF. This is a great module for converting a LEGO kit into a remote control robot. The second new littleBits member is the green color-coded output module long LED (o2). This is a bright white LED fixed to the end of a long stiff flexible wire. The long LED is, therefore, ideal for adding a touch of light at a considerable distance from the littleBits circuit. Figure 6. The actual conversion of the LEGO Attach the littleBits circuit hot rod kit into the Coffin Cruiser begins to the bottom at Step 22 of the building instructions. of the left rear Add the four-module littleBits circuit to axle. the underside of the left rear axle and secure it in place with two black four inch zip ties as in Figure 6. You will have to remove approximately seven previously installed LEGO building elements from this area. When you remove the beige LEGO axle (which you previously added in Step 15, part 1), insert this piece into the littleBits motorMate. Finally, snake the long LED up and into the dashboard area of the driver’s compartment. You may now complete the remainder of the LEGO kit by following the building instructions. In order to give the kit a scary “wobbly” drive, install one large kit tire on the motorMate axle and one of the smaller kit tires on the right rear axle. Likewise, flip this tire wobble arrangement for the front axle: small kit tire on the left front axle and larger kit tire on the right front axle. Furthermore, this wobbly configuration ensures that the working V6 engine (complete with moving piston heads) operates while the Coffin Cruiser is driving around the candy dish (see Figure 7). Just crank the front steering tires

into a tight turn and use the TV remote control to “secretly” maneuver the Coffin Cruiser in a scary drive of death (Figure 8).

The Hand of Fate Speaking of the candy dish, you can make sure that all of your visitors relish your treats by “handing” out candies with a talking hand. The Hand of Fate is our final littleBits project. SERVO 09.2015

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Figure 7. A working V6 engine moves with the Coffin Cruiser.

littleBits DIY PCB Hidden deep inside SparkFun Electronics' free Eagle Parts Master Library (github.com/sparkfun/SparkFun-Eagle-Libraries) are two curiously named schematic and printed circuit board (PCB) patterns: littleBits Male and littleBits Female. These parts are the input and output portions found on all of the littleBits modules. By incorporating these two parts into your SMD/SMT or through-hole schematic diagrams, you can create your own custom littleBits module PCB. In order to test this creation process, I designed a littleBits module for the Atmel ATtiny85 AVR eight-bit microcontroller. My "tinylittleBits" creation attempts to follow along with the littleBits Arduino module (w6). As shown in the schematic (Figure A, for tinylittleBits), this is a very simple layout that combines several SMD components with three through-hole headers: two of the headers enable access to six of the ATtiny85 analog pins, while the 2x3 ICSP header is used for programming the microcontroller. There is one big caveat with this tinylittleBits design, however. Rather than using the officially accepted or approved transient voltage suppressor (TVS) diodes found on the littleBits Arduino module, I made a substitute. Yeah, I'm not sure these two part substitutions are suitable for the design, yet. In point of fact, rather than using the ON Semiconductor ESD9B5-0ST5G diodes, I'm using Bourns SMAJ5.0CA diodes. Why? The reason that I made the substitution is due to the package size of the ON Semiconductor diodes. They are SOD-923! That is way too small of a package size for me to solder. Conversely, my Bourns substitutes are a whopping huge DO-214AC package size that I'm better equipped to solder. Luckily, my substitutes are bidirectional TVS diodes with ESD protection just like the littleBits ones, but there is a slight capacitance difference between the components. Also, sharp-eyed robot builders will notice in Figure A that the part package diagram for the Bourns SMAJ5.0CA diodes in my tinylittleBits schematic is not bidirectional. I wasn't able to quickly locate an Eagle bidirectional diode part in a DO-214AC package. Therefore, I used a generic Schottky diode outline instead. You can see this footprint error on the diode between the signal pin (SIG) and the ground pin (GND) of both littleBits male and littleBits female parts. You can compare the diode differences by studying the littleBits Arduino module schematic and board diagrams. These files are located in the Wire directory of the Open Source Hardware littleBits Eagle files respository

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Figure 8. A Robosapien watches over the Coffin Cruiser. (github.com/littlebitselectronics/eagle-files). The proof of this substitution will be in the fabricating of a tinylittleBits PCB like the one in Figure B. I'm holding off on this step until I can locate a better substitute diode. If a better TVS diode can't be found, then I'll test my design with a small three-PCB test run. When complete, the PCB will need two gray bitSnap connectors. These connectors attach to those SparkFun littleBits male and littleBits female parts that were included in the schematic design and subsequently added to the PCB. You can find 12 bitSnap connectors inside the littleBits Hardware Development Kit (HDK), or you can purchase 12 bitSnaps separately. When you test and finalize your littleBits PCB design, tell the good folks at littleBits about your efforts. If they accept your design for production, you just might get a little bit of fame and a little bit of fortune.

Figure A. My tinylittleBits schematic diagram.

Figure B. The tinylittleBits PCB made with Eagle.

There are two major circuits for the Hand of Fate: the transmitter and receiver. The modules used for these two circuits are shown in Figure 9. The transmitter is the simpler of the two circuits. In it, there are the following modules: power; microphone; and IR LED. While the pink color-coded input microphone module (i21) accepts either voice or sound/music input, the green color-coded output IR LED module (o7) converts the microphone’s audio into light waves. These light waves are then received and decoded by the pink Figure 9. The Hand of Fate requires two color-coded light sensor module littleBits circuits: the transmitter (upper) (i13) that has been switched into and receiver (lower). “light” mode on the receiver. The complete receiver circuit consists of five modules: power; light sensor; speaker; light wire; and servo. As previously noted, the light sensor receives the IR LED light waves and converts them into electrical pulses. These pulses are output through the green color-coded speaker module (o22) as sound. We can further “piggyback” on these pulses with the green color-coded light wire output module (o16) and the similarly green color-coded servo module (o11). In the case of the light wire module, we can wrap the electroluminescent (EL) wire around the candy dish for a pulsing green/blue glow. Likewise, the servo module uses its “turn” mode for moving with the pulses. You will need a couple of extra supplies like those in Figure 10 for completing the Hand of Fate project. A latex Figure 10. A "spork" on a servo moves a Hand of Fate finger. glove (or any other flexible glove) and a craft stick (or a piece of your finest home plastic cutlery, like a “spork”). Attach the craft stick to the screw hub of the servo module. Insert the stick assembly into a finger of choice in the glove. Now, lay the glove on the candy, wrap the candy dish with the EL wire, and secretly hide the entire receiver circuit beside the candy dish. Carefully align the IR LED from the transmitter circuit with the light sensor of the receiver. In a darkened room, you should be able to separate the two circuits by a distance of two feet. Now, speak into the microphone and watch the Hand of Fate spring into life with an accompanying sound and light show (Figure 11). TIP: It helps to speak very closely to the microphone! That’s it. Your Halloween is ready for ghosts and goblins. Finally, to get you in the goblin mood, here’s a joke for you: What kinds of streets do ghosts live on? Dead ends! SV

Figure 11. "Would you like a candy?” asks the Hand of Fate.

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BASIC Bots & PICAXE Processors By Eric Ostendorff

Post comments on this section and find any associated files and/or downloads at www.servomagazine.com/index.php/magazine/article/september2015_Ostendorff.

There's no doubt about it, Arduino is everywhere. It's popular, it's modular, it's open source, it's readily available, and it's cheap. This well-proven soldier has won many battles in the microcontroller war. There are a variety of shields, sketches, and libraries to help people do what they want. In many cases, people don't even have to (learn to) program if they can find a sketch (a program) to do exactly what they want. The Arduino programs in its own version of C/C++ which is powerful and popular, but not the easiest for beginners to learn. There are brackets and voids and spaces and indents — all which must be just so. The sketch/program doesn't read very intuitively until you understand each command. Writing a program from scratch can be fairly daunting to beginners. ’ve been a toy designer for over 30 years. In the toy world, the KISS principle rules: Keep It Simple, Stupid. I have taught numerous programming classes at Mattel Toys and Otis College of Art & Design over the last 15 years to toy designers. Typically, my students are artists and creative types who are quite talented in visual design, but in

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many cases they don’t have much technical background; they do not aspire to become programmers. They rely on the company programmers and EEs who sit “over yonder” in a different group. I’ve always thought it was silly that blinking an LED was black magic to most designers. I’m convinced that a little bit of knowledge about electronics and computer chips is helpful for most people, so I put together an ‘Intro to Programming’ class. In two-hour sessions at Mattel, I had people flashing LEDs, moving servos, beeping speakers, and reading switches. At Otis, the students had harder assignments. They flashed LEDs to strobe their initials in a POV (persistence of vision) display, programmed a Simon-like game, and programmed a simple robot with bump switches. In all cases, people learned a lot and they got hands-on experience making interactive products. Also in all cases, the language they learned to program in was BASIC. That’s the acronym for Beginners All-purpose Symbolic Instruction Code. From my experience, it’s still the easiest and most forgiving language for beginners to learn. The PICAXE is my favorite chip for teaching and controlling the small robots Figure 1. shown in Figure 1. All those bots use the

PICAXE 08M2+ discussed here. PICAXE has a relatively small following stateside; it’s more popular in France and the UK, where it is made by Revolution Education. Although it’s slower than an Arduino and its program memory of 2,048 bytes is tiny, I have found it to be more than enough for most robot projects. It’s a standalone chip (not a board like Arduino), so it must be plugged into a breadboard or circuit to function. This is the first in a series of articles based on a course I teach using the 08M2+ in a small breadboard. The main difference is that you’ll need to build your own hardware, obtaining parts from a few different sources. Think of it as a treasure hunt, with possibilities like these as the treasure: One-Servo Wheeled Robot: www.youtube.com/watch?v=Hf665y_FN3I One-Servo Turtle Bot: www.youtube.com/watch?v=yEUgA33Sdo0 Ball Bot: www.youtube.com/watch?v=xTwfryBBoTs Trike Bot Figure 8: www.youtube.com/watch?v=MPAkAzuY0Bc Trike Bot Line Follower: www.youtube.com/watch?v=4irMxnefgeA Robot Arm does Towers of Hanoi: www.youtube.com/watch?v=Og0JPJ5HQ4s Reading a Servo Position: www.youtube.com/watch?v=hZQx_d902uk A PICAXE has built-in functions to control servos, generate PWM (pulse width modulation) signals for DC motor speed control, and read IR signals from a TV remote, touch pads, and ultrasonic distance sensors. It has built-in ADCs (analog-to-digital converters) for reading simple analog sensors like photocells and thermistors. It also has I2C communications for more sophisticated I/O. It offers pseudomultitasking, where (within limits) several different programs run simultaneously. It can run at several different frequencies up to 32 MHz, although most robotics commands work best at the default speed of 4 MHz (where it is executing several thousand instructions per second). Future articles in this series will get into these functions. A PICAXE can be reprogrammed over 100,000 times. It always retains the last program, which starts running as soon as it is switched on. A program can record data (numbers) in permanent memory

Figure 2.

if desired. It is connected to a PC (via a USB-to-serial adapter) for programming or sending/receiving data, but may be disconnected from the PC otherwise.

➤ PICAXE General PICAXE is a family of microcontrollers which can be programmed using a PC and USB-serial adapter. Programs are written in PICAXE BASIC, using the free PICAXE Editor software. There’s a newer 6.0 editor in Beta, but we’ll use the 5.5 editor for simplicity. We’ll use the smallest and most popular PICAXE: the 08M2+. The tiny (~1/2” square) 08M2+ and support circuitry plug into the pocket-sized battery-powered breadboard module shown in Figure 2. A diagram for this minimum-parts configuration to power and program the 08M2 is shown in Figure 3, which includes two capacitors and two resistors. Figure 3.

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The 08M2+ has four I/O (input/output) pins we can connect to. One is an input only; the other three can be input or output. With some extra work, we can also use two other pins: one input and one output. Larger PICAXE chips (the 14M2 and 20M2) have similar pin connections and can be used and programmed in the same breadboard. They have more I/O pins which consume more space on the breadboard, leaving less room for external circuitry. The USB-serial adapter plugs into three holes on the top right of the breadboard for programming and sending data to/from the PC.

➤ Breadboard The solderless breadboard provides a quick and easy way to make electrical connections for experimenting. The breadboard has a grid of holes 10 across and 17 high. Per Figure 3, each horizontal row of five adjacent holes are internally connected to join parts together electrically. Parts and wires simply plug in to connect. The PICAXE 08M2 and its required components and wires occupy the top five rows, leaving 12 rows open for connecting other components and jumper wires. The system allows great flexibility; there are several “right” ways to locate and connect parts together, plus many WRONG ways (we’ll discuss this next). Any vacant rows can be used, provided all the proper connections are made via the internal five row conductors. In general, some planning and creative bending on component leads allows a neater layout with fewer jumper wires. Three AA alkaline batteries provide 4.5 volts to power the PICAXE, circuitry, and servos. The battery box has an on/off slide switch which should be turned off after use to save battery power. The PICAXE, circuitry, and servos will slowly drain the batteries. The small digital voltmeter module is helpful to display the battery condition and can also be used to monitor some other voltages. CAUTION: The breadboard’s flexibility also allows wiring mistakes to be made. Some mistakes simply prevent a circuit from working and can be corrected. Other mistakes may instantly damage (“release the magic smoke”) the PICAXE or other component. When connecting parts and wires, always turn the power off. Work carefully. Those tiny breadboard holes are very close together. Use a variety of jumper wire colors to keep track of your connections. Red is generally used for battery +, black for battery - (a.k.a., ground), and other colors for signals to/from sensors and servos. A few components (resistors, photocells, thermistors, some capacitors) don’t have any polarity and can be installed in either direction. Other components are polarity sensitive. Some are marked or coded. Electrolytic capacitors and diodes have a stripe to mark their negative side. LEDs have a long positive (+) lead.

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Other polarity-sensitive components have unmarked and unique pin configurations that must be determined from a datasheet. Check and double-check all connections before applying power. It’s possible to create a short circuit in the breadboard. NEVER connect the battery + and - connections directly together. If you ever see a tiny spark or feel parts, wires, or batteries getting warm, turn the power switch off immediately and find the problem. Just a few seconds of shorting the battery leads together can kill the batteries, requiring replacement. Definitely get a multimeter. You can spend a lot or a little. Harbor Freight’s $5 multimeter is a great first purchase. It has more functions than you initially need. A multimeter can measure voltage, current, and resistance, and is invaluable in finding problems like bad batteries, low voltage, bad connections, wrong resistance, etc. The HF multimeter has a one-shot fuse in it, so it can be zapped with high voltage. However, in the PICAXE world of five volts and less, even a cheap multimeter is fairly forgiving and should last a long time. Swap meets and hamfests can also be great places to find multimeters and other electrical tools and parts. (The TRW swap meet near Los Angeles, CA is a goldmine on the last Saturday of each month.)

➤ Building the Breadboard The 3xAA switched battery box and 170-hole breadboard can be bought from various suppliers; the breadboard has a peel-off adhesive back. Assemble as shown in Figure 2, leaving room for the voltmeter module above. Plug a two-conductor 90 degree header into the top left of the breadboard. The three-wire 0V-30V voltmeter sells on eBay for under $2. Use hot glue or CA glue to hold it in place, making sure the switch is accessible. Solder the black battery and voltmeter wires to the top header pin and the red battery and voltmeter wires to the lower header pin. Leave the white voltmeter wire longer so it can be repositioned and soldered to a single 90 degree header pin. For now, plug it in beside the red wire to measure battery voltage. After testing that with batteries, turn the switch off and plug in the PICAXE, two resistors, two capacitors, and jumper wire in the holes shown in Figure 3.

➤ USB/Serial Adapter We need an adapter to connect the PC to our PICAXE breadboard. PICAXE’s own AXE027 and USB010 cables work fine as does Parallax’s FTDI-based adapter. You can

Where to buy PICAXE chips: RobotMesh.com • phanderson.com RobotShop.com • SparkFun.com

buy those for $15-$20, but you’ll still have to hack their connectors into a three-pin male to plug into the breadboard. For a bit more hacking, you can make your own and save some bucks. Silicon Lab’s CP210x (also CH340) adapters are widely available for a dollar or two and work great with Windows 8, but they need their signals inverted. Avoid Prolific’s 2303 adapter — a no-go for Win8 and later. PICAXE forum member, Goeytex shows how to add a 74HC14 inverter in the schematic in Figure 4. Having made many of these, I can say the quickest one to wire up is the white CP2102 board shown in Figure 2 using the chip-centric diagram in Figure 5. Three CP2102 connections line up perfectly with the 74HC14, making for a simple solder job on a small perfboard scrap. End up with three male pins pointing down per Figure 5. These pins fit into the breadboard. I glue a small plastic strip on the back of the perfboard as a polarizer to help align the pins with the top edge of the breadboard. You can also use a servo extension cable if desired to connect the USB adapter to the breadboard some distance away. Download CP2102/CP210x VCP drivers from www.silabs.com/products/ mcu/Pages/USBtoUARTBridge VCPDrivers.aspx and use the Device Manager to verify operation and COM port number. Download the PICAXE Editor v5.5 from www.picaxe.com/ Software/ PICAXE/PICAXEProgramming-Editor. Run the Editor and watch for the OPTIONS dialog box (click the OPTIONS button on top if necessary); see Figure 6. Click Serial Port, select your adapter’s COM port number 1-15, and click APPLY.

Figure 4.

Figure 5.

➤ Moment of Truth Now, plug the USB adapter into your breadboard (watch those pins!) with the power switch off. Still in the OPTIONS dialog box, click MODE, select 08M2, and click “Check Firmware Version.” Immediately turn on the power switch; if all goes well, you’ll get a FIRMWARE dialog box. (If you get a five second delay and an ERROR dialog

Figure 6.

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box, you’ll need to find and correct the problem.) Close the FIRMWARE and OPTIONS boxes to return to the Editor. If your PICAXE is brand new, you should see the SERIAL TERMINAL window displaying a nonstop stream of “Hello, I am your PICAXE-08M2” messages, which is the factoryloaded test program. Your first program will overwrite it. If you don’t see anything, press F8 to open the SERIAL TERMINAL window. Now, close the Terminal window and type in the classic first program: do sertxd (“hello world”,13,10) loop

Click the PROGRAM button to download and run the program. If you now see “hello world” messages in the Serial Terminal window, you’re a programmer and a hardware whiz too. Fairly obviously, you could change “hello world” to any message you’d like. The 13 is the return character, and 10 is the line feed character. SERTXD is the command for Serial Transmit Data. Memorize it. You’ll use that command a lot. Have some fun programming before hooking up any circuits. You can’t permanently damage the PICAXE by programming errors alone. The worst you might be able to do is disconnect it when a hard reset is required. (Simpler than it sounds.) If things ever get stuck or you can’t download a program, just turn the PICAXE power off. Click “PROGRAM” first, then turn on the power. Done.

➤ Programming Writing programs is a numbers game, no doubt about it. If you’re just starting out, some of this next material may seem totally Greek, but as you play around it will become clearer. Keep at it! PICAXE chips use integer math only — no decimals, no negatives. Fractions and remainders are dropped/truncated. Three types of general-purpose variables are used to store numbers in a program. All GP variables are initialized to zero at power-up/reset. BYTE variables B0-B27 are mainly used. These can store a positive number from 0-255. Note that 255 + 1 = 0 since numbers wrap around; 250 + 10 = 4; 2 - 3 = 255; etc. Know it, embrace it! BIT variables bit 0-bit 15 have a value of either 0 or 1, and are often used as simple flags in programs. BYTE variable B0 is made from and overwrites bit 0-bit 7, and vice versa. Changing B0 will change one or more of bit 0-bit 7 and vice versa. Likewise, BYTE variable B1 is made from and overwrites bit 8-bit 15: B0=bit7:bit6:bit5:bit4:bit3:bit2:bit1:bit0 B1=bit15:bit14:bit13:bit13:bit12:bit11:bit10:bit9 :bit8

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WORD variables W0-W13 are made of two BYTE variables, and can have a value from 0-65535. Likewise, 65535 + 1 = 0, 2 - 3 = 65535, etc. Also, W0 is made from and overwrites BYTE variables B0 and B1, and vice versa. Changing B0 or B1 changes W0. Adjusting W0 changes either (or both) B0 and B1 and vice versa. Likewise, W1 is made from B2 and B3, W2 is made from B4 and B5, etc.: W0=B1:B0 W4=B7:B6...

W2=B3:B2 W12=B25:B24

W3=B5:B4 W13=B27:B26

You can give a variable a text name: symbol COUNTER = B0 defines “COUNTER” as variable B0. Math functions include: + (add) / (divide)

- (subtract) *(multiply) // (remainder after division)

plus AND OR and more, in the PICAXE Editor (see Help/Manual 2). The word “LET” is optional but implied in commands such as: LET B2=4*B1+B3/7

which is identical to

B2=4*B1+B3/7

The expression is evaluated simply left to right; there is no hierarchy of operations. In the equation above, if B1 = 10 and B3 = 13, then B2 will be calculated as 7. That is: 4*10=40

+13=53

/7=7

53/7=7.57

(Using integer math, the fraction is dropped.) Although, LET will be required in operations like: IF B1>10 THEN LET B4=0

B0 = B0/4 is a valid command, meaning the new value of B0 is the old value divided by four. SERIAL TERMINAL. As we saw with “hello world,” the Serial Terminal window (F8) allows the PICAXE and PC to send messages and data through the programming cable. Remember that the PICAXE is doing all the math, and your PC is just a display. Variable values can be displayed using the Serial Terminal too: SERTXD (“The value of B0 is “,#B0, 13,10)

Anything in quotes is a text string, printed just as typed. #B0 shows the value of B0; again, 13 is the return character, and 10 is the line feed character. Here are three different looping programs to type in and modify to learn about manipulating numbers. Play around and see what happens. Ignore comments after the apostrophes:

main:

‘ create a location/marker ‘ called ‘main’ sertxd(#b0,13,10) ‘ display the value of ‘ variable b0 in the serial ‘ terminal b0=b0+5 ‘ add five to the old value of b0 pause 200 ‘ wait 200 milliseconds for ‘ display purposes goto main ‘ jump back to location ‘main’ ‘ and repeat

Whatever you do, don’t start blinking any LEDs without me. Those HIGH, LOW, and TOGGLE commands can be really tricky. (I’m kidding, of course.) Manual 1 (located under the HELP tab in the PICAXE Programming Editor) shows how to blink LEDs under “Quick Start.” Also check out BASIC Simulation, and visit www.picaxe.com for the manuals, as well. You can program a PICAXE using simulation even if you don’t have one. Have fun learning until next time. SV

do ‘ start a DO loop sertxd(#b1,13,10) ‘ display the value of ‘ variable b1 in the serial ‘ terminal inc b1 ‘ increment variable b1 (add one ‘ to the previous value) pause 200 ‘ wait 200 milliseconds for ‘ display purposes loop ‘ loop back to do which started ‘ this loop for b7=99 to 0 step -3 ‘ start a for/next loop, b7 starts at 99 ‘ and gets reduced by 3 each loop sertxd(#b7,13,10) ‘ display the value of variable b7 in the ‘ serial terminal pause 200 ‘ wait 200 milliseconds for ‘ display purposes next ‘ loop back to ‘for’

➤ Learning Resources There is an online command listing at the PICAXE Editor which contains three PDF manuals under the HELP menu with lots more info than I can ever present here. Next time, we’ll get into some hardware, so you should order these parts now if you want to play along: 1. Servos: Our 08M2+ can control three servos. The alkaline batteries are the limiter here. Get three mini “9 gram” servos. You may want to modify one for continuous rotation. Google it! 2. Ultrasonic sensor: HC-SR04 sensors cost less than a soda now. Order two! 3. LEDs: Any size and color, and get a 220 ohm resistor for each. 4. IR remote control: Get a 38 kHz IR receiver module (many types under $1 each) and a universal IR remote control which is set up to control SONY televisions. The best remote with the most usable buttons is $2 on eBay; search for TV-139F. 5. Analog sensors: 10K potentiometer, thermistor, photocell, and a Sharp IR analog distance sensor

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www.robotmesh.com/picaxe SERVO 09.2015

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Teams file in from around the country to compete in another NASA robotic mining matchup.

NASA’s 6th Annual Robotic Mining Competition By Holden Berry

In the blistering Florida May heat, 49 teams gathered under an air conditioned tent in the NASA Visitor Center. The sound of mechanical work and the rumble of a crowd was penetrating the hot air and escaping outside where another huge tent — this one housing an arena and bleachers — could be seen. Another year, another NASA sponsored Robotic Mining Competition.

NASA

has put on this event for six years now, starting with only about 13 teams. Every year, the competition has grown in size, innovation, and difficulty. NASA created this competition for university-level students in order to assist them with a very real and practical issue: mining in space. With the idea of space exploration quickly turning into space habitation, humans are going to need certain things

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Go to www.servomagazine.com/index.php/magazine /article/september2015_Berry to comment on this article.

while living on a new planet. Access to raw natural materials is among the most important aspects of living in space, right up there with access to oxygen and water. NASA wanted help with their creative and innovative process, and in 2010 enlisted the help of university students all over the country. Teams from over 20 different schools came to Cape Canaveral to check out the visitor complex and more importantly, compete. Montana State University came out on top that year winning the grand prize. The competition has only grown since that inaugural 2010 year, with over twice the amount of teams entering this year. So, what all is there to this competition? Well, teams are doing more than sending a robot out to collect dirt. A special material called Black Point-1 (BP-1) is used to simulate the regolith on the Moon, and is extremely fine and often difficult for wheels to maneuver in. Participating teams must navigate the arena using either wireless controls or autonomous programming. The person controlling the robot must sit in NASA’s mobile mission control cars, which could realistically be used in space some day in order to simulate an actual mission occurring on another world. The robots must then collect a minimum of 10 Kg of regolith in their two separate runs, and deposit the mined substance in a collection bin. Although the mining portion of the competition is the one that gets the most focus, there are many other aspects of this event that must also be taken care of by the participants. Teams must do an outreach program and write a report on it. This could be anything from presenting their robot at a local elementary school to doing a small demonstration at a local library — anything that benefits the community and brings more awareness to STEM (Science,

Technology, Engineering, and Mathematics) education. Teams must also write up a systems engineering paper — a common task in the engineering career world. It is a document that states how the team will design, test, build, and operate their system. It gives teams practical real world experience in the career field they will likely go into. Other competition aspects include an optional slide presentation and team spirit. Every area of the competition has an award and prizes. A team could win the spirit section and be awarded a $500 team scholarship, win the mining competition and receive a $3,000 team scholarship, or take home the grand prize of the Joe Kosmo Award for Excellence and get $5,000 for the team. The Joe Kosmo trophy can be gained by being awarded the most points at the end of the competition with the spirit, slide presentation, mining, systems engineering paper, and outreach project report all being worth a certain amount of points. Teams controlled their robots while isolated in the NASA The great part about this competition is that teams mobile command center. have been constantly pushed for innovation, because every exuded confidence. “We’re one of the teams to be here year NASA changes up the rules slightly in response to every year of the event since 2010,” the sponsor told me. increasingly better performances from the teams. These “We’ve been competitive every year.” In addition to this tweaks force teams to change up their designs and develop year’s and their 2012 victories, Alabama took home third new ideas that drive new technological breakthroughs. This year, they included the idea of mining ice, and place in 2014, and second the year before that, so mimicked ice by including specifically sized gravel in the competitive is a bit of an understatement. regolith, with the gravel simulating the actual consistency and How has this team managed to stay so successful weight of ice. Teams are responding to these changes with throughout the tournament? Well, the answer comes in new perspectives, and continually strive for the best results. multiple parts. An obvious answer is that they have been at The first year of the competition only one team’s robot this competition every year so far, so they have years of managed to successfully mine the BP-1. The very next year experience over some of the rookie teams. Each year, almost half the teams were successful because they were they’ve had a successful robot, and then been able to build able to build off the previous team’s progress. This year, on top of that success. This explains how they were so many of the robots were autonomous and were able to successful with the autonomy system, since they’ve had mine without needing a person wirelessly controlling it. NASA loves this competition because they receive new innovations and ideas for real future issues from some of the brightest engineering minds in the country. So, how did teams fair this year in competing? Last year, we saw the West Virginia Mountaineer team take home the Joe Kosmo trophy, winning both the onsite mining challenge and the outreach project report. However, the Mountaineers did not return to reclaim their trophy. Instead, Alabama University in collaboration with Shelton State repeated their 2012 grand prize victory. Alabama took first place in the mining segment and the slide show presentation, and also managed to nab second in the outreach program and systems engineering paper. In addition to the Joe Kosmo Award for Excellence, the Alabama and Shelton State team won the Autonomy Award and the Efficient Use of Communications Power Award. I had a chance to talk The University of Central to a teacher sponsor and a few students on the A UCF team member runs Florida (UCF) robot runs in maintenance on their robot. Alabama team, and one thing is for sure, they all the practice pit. SERVO 09.2015

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A team shows off their robot on the open viewing day. years to perfect the mechanics and nuances of driving and mining, and were now able to focus on the programming. “We have a full 24 x 12 ft pit full of masonry sand” stated the sponsor. A pit of their own is actually more than many teams had. The UCF team who were in their first year of the competition used a local beach volleyball court to practice. Although UCF didn’t place this year, they’re encouraged for next year, when they’ll be able to perfect their auger method. Being a rookie team in this competition is very challenging, but the teams that have returned come back with a full year’s work and knowledge with them. Alabama’s practice pit is state-of-the-art, and although they couldn’t fill it with BP-1 — which is actually synthesized moon dirt — they did fill it with pure masonry sand, “which is actually finer than the BP-1 material,” stated an Alabama University student. “We have more traction here than we do back home. If we can drive there, then we can drive here.” Alabama boasted the added benefit of having students in nearly every scientific discipline you could think of: engineering majors, math majors, aerospace, physics, and the list goes on. In addition to those students, the program

A team poses with their robot before a mining run. is backed by dedicated professors who are passionate about the success of their robots and — more importantly — their students. So, another year of innovation has come and gone at NASA. This year was certainly eventful and useful. Before going and seeing the competition, I really had no idea what to expect. When I got there, I was surprised by the sheer volume of people, rows and rows of robots, and teams repairing them. A tent filled with machinery noise, saws ripping through metal, people trying to talk over those saws, then more people trying to talk over those people trying to talk over the saws. However, I didn’t need to hear anyone to see what this competition was all about. I didn’t need to hear the almost rehearsed sounding answers to “How long have you been practicing, oh and how’s your mining method doing, and how are your wheels holding up?” to understand the importance of this competition. Not only is NASA gaining new ideas and solutions to problems they may face in space and seeing firsthand trials of potential technologies, but they’re also bringing out the best in a huge group of some of the smartest young adults in the country. They’re letting these students express their ideas and exercise their critical and analytical thinking skills through real life practical situations, and then rewarding them for it. I personally look forward to seeing how ingenious these robots become over the next few years. SV

Fans watch teams run their robots in the BP-1 sand pits.

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BattleBots 2015 That’s a Wrap By Michael "Fuzzy" Mauldin, Team Toad Photos by Michael "Fuzzy" Mauldin and BattleBots, Inc.

Post comments on this article at www.servomagazine.com/index.php/ magazine/article/september2015_Mauldin.

Over the course of three days, two dozen robots came together to fight for BattleBots’ coveted Giant Nut. Now that the tournament is over, let’s take a closer look at some of the details of how the event was run.

Who’s the Best Robot? The most important thing to remember is that BattleBots is a single-elimination tournament with one champion. In addition to the Giant Nut trophy, the winning team received a $60,500 cash prize. For this first season on ABC, veteran robot teams from the United States and the United Kingdom were invited to submit design applications for a 250 pound fighting robot. Twenty-four teams were chosen as competitors, with six more alternate teams selected to ensure a complete event with 27 fights.

Rock, Paper, Scissors The second most important thing to remember about BattleBots is that it is entertainment that must survive on network television. In the past, the game was “spinner, flipper, wedge.” The most pejorative phrase you could utter about someone’s robot was that it’s a “boring wedge,” and there were a few fights between slow moving wedge-bots that were painful to watch. The fact remained that the easiest way to beat a powerful spinner was to use a low angled wedge to deflect its energy. Figure 1 shows three archetypal robots from the 2015 BattleBots event. At the left is Captain Shrederator, a full-body spinner with the largest rotating mass in the tournament. At the upper right is Bronco, the most powerful flipper at the event. At the lower right is Stinger the Killer Bee, a “wedgy” lifter which knocked out Shrederator and, in turn, was knocked out by Bronco. Bronco was done in by another spinner. To increase the audience appeal for this new show on ABC, BattleBots instituted an active weapon requirement, to wit:

24 had a spinning weapon. The less obvious effect is to reduce the number of flippers. Only two robots had lifting weapons with sufficient velocity to launch an opponent off the ground. That left eight robots that are best described as lifting wedges or clamping lifters, and a few with flamethrowers for added excitement.

Missed Opportunity One of the most exciting robots I had hoped to see fight was Beta from the United Kingdom. Beta is a hammer-bot, with a very heavy metal cylinder that comes down with enough force to lift the body of the robot completely off the ground. Every robot that goes into the BattleBox should be built to withstand blows from the “pulverizers” — driver-controlled hammers in each corner of the arena. A hammer bot must be very powerful to be effective, and in testing, Beta hit much harder than the pulverizers. Unfortunately, on the trans-Atlantic flight from England to San Francisco, CA the airline lost the bag containing their Figure 1.

The first obvious effect of this rule is to increase the number of spinners; over half of the initial field of SERVO 09.2015

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Figure 2.

custom electronics and chargers. In spite of valiant efforts to fashion a work-around the week of the event, the team was unable to get the robot to function well enough to compete. Beta was replaced in the tournament by Counter Revolution, a double vertical spinner.

Spinners In my preview article in July’s issue, I showed the guts of an unnamed robot (page 54). It was HyperShock driven by Will Bales (Figure 2, top left). Also shown clockwise from HyperShock are Wrecks and Plan X; HyperShock being dismantled by IceWave during a grudge match; Warhead flying like a bird; Nightmare and its team; Tombstone being tested in the pits; Sweet Revenge spinning against the hammer bot Radioactive; the dual vertical spinner, Counter Revolution; and Witch Doctor, a colorful vertical drum spinner.

Clampy Lifters and Lifting Clampers: On Fire! Figure 3 shows some of the non-spinners. Clockwise from top left are: Overhaul and LockJaw; Mohawk with flames; Bite Force; Ghost Raptor vs. Complete Control; Razorback; and Chomp vs. Overdrive. Each of these had a movable appendage that could either lift the opponent off the ground or clamp onto the opponent.

Figure 3.

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Bite Force may have been the most versatile robot in the event, fighting with a removable clamping arm and two different wedge attachments — one of which was actually assembled the week of the event.

Tournament Structure, Prelims, and Seeding Although it might be fun to think about it, you can’t just throw two dozen robots into the arena and give the trophy to the last one moving. (Well, you could, but it would be hard to film and make a six-episode season.) The task of organizing the event into a tournament of one-on-one fights falls to the Tournament Selection Committee (TSC), which is a small group comprised of BattleBots founders, former BattleBot contestants, and executive producers of the show itself. Membership in this group had to be the hardest job at BattleBots, because each night after the action was over and the audience left, the committee members were tasked with evaluating the robots and deciding what would happen the next day. After the 24 robots passed safety inspection, each TSC member and each safety inspector scored each robot in four categories: Aggression: How mean and fast the robot seems Control: A measure of the skill of the robot’s driver Weapons: How destructive the weapon appears Defense: A measure of the robot’s durability Figure 4 shows the statistics given for the final match between Tombstone and Bite Force. The numbers you see on the televised graphics are averages of the individual scores. The result is much like the BCS poll numbers you see each week during college football season (BCS is Bowl Championship Series). You can argue endlessly about how accurate the numbers are, but someone has to sit down and reduce a slew of information down to a single number you can use to decide who fights who. The 2015 tournament was split into two parts. First, there were 12 preliminary matches to

Figure 4.

Figure 5.

winnow the 24 competitors down to 12. Then, four wildcards were awarded to robots that lost their first fight, but showed promise. Twelve winners and four wildcards gave 16 robots to fit into a standard seeded bracket. The purpose of “seeding” a tournament is to use the best information available about the competitors to arrange the bracket so that the best players meet as late as possible in the tournament. Once the prelims were over, the committee chose the four wildcards and assigned seeds based on the performance of each robot up to that point, as well as its entertainment value and appearance. One specific question I did ask was about the re-match between LockJaw and Overhaul. In the preliminary round, LockJaw won a split-decision against Overhaul. After the seedings were assigned, it was totally coincidental that these two robots met again.

The Hazards One familiar feature of the BattleBox is the presence of hazards: actively destructive machinery to ensnare and damage unwary robots. As mentioned earlier, the pulverizers are four large hammers — one in each corner of the box. As in the college-level BattleBotsIQ events, the pulverizers are now controlled by the teams themselves. The red team controls two hammers and the blue team controls the other two. Colored circular targets painted on the BattleBox floor show where the hammers will strike, but it is up to the team member pressing the button to make a hit. The killsaws were not active for the preliminary fights, but in later rounds, were randomly activated by a computer. That meant the killsaws were not much of a factor in any of the fights. The most destructive weapon in the entire tournament had to be the screw hazards. In past events, they have been located near the corners, but for the 2015 ABC event they were moved to the middle of each wall. They also seemed more powerful this year. More robots were knocked out by being pushed into the screws and dragged to their demise than any other cause of “death.”

The Brackets Figure 5 shows the brackets through to the quarter-

Figure 6.

finals. The most energetic fight of the entire tournament was Tombstone versus Witch Doctor — the only spinner-vsspinner fight in the elimination rounds (there were three spinner-vs-spinner fights in the prelims, but you didn’t see the two spinning weapons hit each other in any of those fights). Team Hardcore has several different weapon bars that they can attach to Tombstone for different fights. Against Witch Doctor, they used a shorter S7 tool steel bar that had previously seen action in super heavyweight fights back in Season 5 of the Comedy Central show. It has also been used on their heavyweight robot, Last Rites in the intervening decade. Ray Billings told me this bar had been used in about 25 matches. In this fight, the blade broke completely in half — probably because of stress fractures that had been created in those previous events. Figure 6 shows Tombstone’s broken blade, along with Bronco’s busted flipper. One of my favorite matches of the entire tournament was the quarterfinal matchup between the flipper, Bronco and the lifter, Stinger the Killer Bee. Stinger is a slightly heavier version of the heavyweight, Sewer Snake that has been a ComBots and RoboGames champion. In addition to a modular lifting weapon attachment, Stinger has a flame thrower. Figure 7 shows driver, Matt Maxham giving us a sneak peak at the special weapon attachment he used in the quarterfinal match. Bronco was able to throw Stinger into the air several times, flipping the yellow bot end-over-end while the flame thrower made flaming spirals in the air. Bronco scored a knockout by flipping Stinger over the arena bumpers and SERVO 09.2015

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Figure 7.

Figure 8.

Semi-Finals

into the space between the bumpers and the exit doors. The biggest upset of the tournament had to be the quarter-final match between the #2 seeded IceWave and the #10 seeded Ghost Raptor. IceWave uses a gasoline engine to power a 47 pound spinning bar, and had previously made quick work of RazorBack and Chomp. Chuck Pitzer made good use of the Lincoln Welders professionals to craft a “keep away stick” that bolted onto the lifter of Ghost Raptor. It was labelled “De-Icer.” The large engine pod on top of IceWave made it vulnerable to this attachment. Ghost Raptor was able to grab the engine pod and push IceWave backwards; this caused the spinning bar to score only glancing blows on the front armor of Ghost Raptor. A final half-hearted hit to the side of Ghost Raptor flipped IceWave upside-down, and it was counted out.

Figure 9.

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By the semi-final matches, there was only one spinner left in the tournament: Tombstone. As the graph in Figure 8 shows, spinners tend to die a little faster than lifters and flippers or — as in the case of Ghost Raptor — they lose their spinners and become lifters. The pivotal match of the tournament was the #1 seed Tombstone versus the #4 seed Bronco. This fight produced the most sparks because Tombstone has a vicious spinning weapon, and Bronco used a lot of titanium, giving showers of white sparks on every hit. After ripping off the right wheel guard of Bronco, Tombstone also removed Bronco’s right front tire. Bronco was unable to drive and the referee started counting him out. According to Ray Billings, whenever the count got close to zero, Bronco would fire his flipper, and the referee would stop counting. The enormous power of Bronco’s weapon can be seen in Figure 9, showing Bronco throwing itself over five feet in the air. At this point, Tombstone has won the match. All he had to do was head back to his starting square and wait for the clock to run out. However, you never want to leave the outcome to the judges. So, Ray lined up for one last hit, which probably cost him the tournament. Tombstone was upside down and when the blade struck Bronco, it caused Tombstone’s body to flex, shearing the bolts securing its top plate that, in turn, holds the batteries in place. As Tombstone cartwheeled to a stop in the middle of the arena, his A123 battery packs spilled out onto the floor. Ray won the fight, but the damage would haunt him in the finals. The other semi-final match was the #10 seeded bracket-busting Ghost Raptor, which had previously beaten the #7 seed, Warrior Clan and the #2 seed, IceWave. Having lost its spinner, Ghost Raptor was now just a lifter, and was out-controlled by the clamping ability of Bite Force. Bite Force was able to grasp its opponent and feed the screws their last victim. This was one of only two times Bite Force fought in its standard configuration with the lifter and the clamper attached.

Figure 10.

Finals After the semi-finals, both victors headed to the pits and the Lincoln Welders tent for repairs. Tombstone got some welding done on the frame that holds the spinning weapon, and Bite Force got its wedge trimmed a little so it wouldn’t drag on the arena floor. I said earlier that the last hit by Tombstone in the semis cost Ray the tournament. More specifically, because the main battery packs he’d been using the whole tournament had spilled out of the robot, Ray was concerned that the packs may have been damaged. So, he directed his team to switch to a backup set of battery packs for the finals. These had tested out fine at home, but had not seen any combat up to this point. Tombstone uses four A123 packs for the weapon motor: two strings of two packs, or “2S2P.” As soon as the finals started, Ray noticed that Tombstone was not spinning up as quickly as it had previously. This gave Bite Force a chance to take a couple of slightly less vicious hits. Ray theorized that one of the four packs was faulty, meaning that all of the current had to flow through the other pack. After the first couple of hits, that battery pack caught fire and Tombstone started smoking. Eventually, the weapon blade stopped turning all together. The match and the tournament went to Bite Force.

Luck of the Draw The lesson here is that to win the Giant Nut, you have to win five fights in a row. It’s not enough to be the most destructive robot. You have to have the toughness and pit skills to keep your robot working through all of the fights. Plus, you might need to resist the crowd yelling “Finish him!” Some really good destructive robots like Captain Shrederator and WarHead had unlucky draws. Stinger and Bite Force are really good wedges. These spinners might

have gone much farther if they’d had other clamp bots or spinners as their initial opponents. As for the finals, I’ve spoken to both drivers, and they both agree that if Tombstone didn’t take the last hit against Bronco and had his main batteries at full strength, the outcome of that match might have been different. One lucky (or unlucky) hit and a robot can be out. I would have liked to have seen that fight.

Awards Figure 10 (top left) shows Team Aptyx and Bite Force with the Giant Nut. From left to right are team members Teena Liu, Cory McBride, Travis Covington, and Paul’s parents, Joan and Anthony Ventimiglia (not pictured: Jeremiah Jinno). In addition to the Championship trophy, there were two “Giant Bolt” trophies awarded. The middle photo shows Ray Billings with the “Most Destructive Robot” trophy (not pictured are team members Justin Billings and Rick Russ). Warhead won “Best Designer,” shown at right: Simon Scott, James Cooper, and Ian Lewis (not pictured: Gillian Blood Lewis). Each award also came with a $25,000 prize. It was announced at the awards ceremony that the Giant Nut and the Giant Bolt trophies are the same thread size, so they can be screwed together. You can bet that Ray Billings is already planning upgrades to Tombstone to verify that fact next year.

Next? As this issue of SERVO goes to press, we do not yet know whether ABC will renew BattleBots for a second season. To receive the latest information, sign up for the BattleBots email mailing list at BattleBots.com. SV

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Let’s Talk Bots This year's BattleBots were bigger and more powerful than ever, featuring technology and innovative designs never before seen on television. One of the more inventive and imaginative designs from this year's field of 24 competitors was the gyroscopic walker, Wrecks built by six veteran robot builders from the Berkeley, CA area: Micah "Chewy" Leibowitz, Dan Chatterton, Joe Sena, James Arluck, Orion Beach, and Adrian “Bunny” Dorsey. Together they are Team Wrecks.

Team Wrecks’ logo. Adrian "Bunny" Dorsey, Micah "Chewy" Leibowitz, Dan Chatterton, Orion Beach, Joe Sena, and James Arluck.

Wrecks' frame made of formed and welded steel.

Dan Chatterton was gracious enough to take some time to talk with me about the creation of Wrecks and his team's experience on BattleBots. Dan is a CNC machinist by trade, but likes to think of himself as a "professional tinkerer." He is extremely interested in how things work and enjoys figuring out how to build just about anything out of components scavenged from garage sales, surplus stores, or from dumpster diving. SERVO: How did you get started in competitive robotics? Chatterton: As I started high school, BattleBots became a huge TV success, and I aspired to build a bot and be on the show. It was over before I had the chance, though, and my opportunity didn't return until college when I met Zachary Lytle (check out his SERVO articles in October 2012 and April 2013). He ran a robotics club where we built smaller fighting robots. I started small, helped with some larger ones, and eventually teamed up

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with Orion Beach to build our 2012 Robolympics (RoboGames) silver medalist 220 pound Heavyweight bot, The Electric Boogaloo. SERVO: Tell me about your robot, its weapon, and how you designed and built it. Chatterton: Wrecks was designed after two other bots. One was my Antweight, Gyrobot which is the original gyroscopic walker. What that means is that it uses the spinning blade as a gyroscope, then tilts that gyroscope side to side to cause the entire bot to take steps forward. Without the blade spinning, it just rocks back and forth and doesn't go anywhere. Once the blade is spun up, though, gyroscopic precession causes the bot to move forward as it is tilted. The other bot it is designed after is one that Orion and I built a few years ago, The Electric Boogaloo. We copied several of the strong points in terms of frame and weapon design, and implemented those into Wrecks. The gyroscopic walker design originated from watching

by Chris and Tiffany Olin

Post comments on this article at www.servomagazine.com/index.php /magazine/article/september2015_Olin.

many vertical spinner robots struggle with turning. Sleeping in one Saturday morning daydreaming about bot designs, it hit me that I could actually use the gyroscopic force of the spinning blade to move the entire bot. The first prototype was about three-quarters of a pound, a bunch of Wrecks' 28" 35 pound blade. With parts taped to an aluminum plate, the motor at full speed, this blade and a motor on a tilty piece that spun spins over 250 miles per hour! a small scooter wheel. As afraid as I Micah “Chewy” Leibowitz milling a frame component. was of the rubber on the wheel flying purposes, so we shortened off as I spun it up, it actually worked right off the bat. the name to Wrecks. Gyrobot took another half year to come together. SERVO: What did you Improvements and some re-designs later, I have a pretty learn from your BattleBots good idea of how to make this arrangement effective. experience? One thing we knew we were not going to receive with Chatterton: The Wrecks was any kind of weight bonus. Many competitions technical act of building allow a weight bonus for walking bots, though what types yields several technical skills. of walking designs get that bonus are up to the Event A lot of it is applying skills I Organizer. With that said, BattleBots said nothing of the already have. Some people sort this time around, so we built it to the normal limit of say that it's just pointless 250 pounds. What they really wanted people to bring, destruction. However, there however, was something new, innovative, cool, surprising, is a whole aspect of it that exciting ... things that would capture the audience James Arluck grinding away at AR400 steel. many people overlook. Yeah, (figuratively, not literally). We also had something to prove; it's a lot of fun, and I thoroughly enjoy fighting robots. that anybody could come out with something totally unlike What I care about more than winning, though, is the any other bot done before and rock. We didn't win, but I audience. I want the audience to enjoy it because when a would certainly say we rocked. In that aspect, we totally bunch of kids see cool fighting bots, they often want to won. We proved that it is a viable design. SERVO: Did it live up to your expectations? learn more about it. With that comes all kinds of interest in Chatterton: It didn't quite live up to them. It's okay science, math, physics, etc. I've already learned a lot, and though; we learned a lot and now know what needs to there are always little things I'm picking up here and there. happen for Wrecks to — as I like to put it — stomp face. The The real treasure is how much other people are inspired to control was wonky, the blade was a bit slow, and it had a learn. I'm a huge proponent of education, and if just one hard time self-righting. All three of those things we're kid sees one of my bots and is inspired to learn, then in my already working on the improvement for. Also, we'll have a eyes the design is effective. bit more time to add to the "intimidation factor." When it returns, it will be fearsome and ruthless. SERVO: How did you pick your robot/team name? Chatterton: Our robot’s name was actually suggested In this year's BattleBots tournament, Team Busted Nuts by Orion's girlfriend, Addy. Gyroscopic walkers (including Robotics put the whammy on their competition with their both Gyrobot and Wrecks) lumber around in a very multi-bot Witch Doctor and Shaman. tyrannosaurus-rex fashion, so she suggested the name Busted Nuts Robotics is made up of four talented robot Blade-o-saurus-rex. Unfortunately, this was a bit long for TV

Team Witch Doctor and Shaman

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during the freshman open house, and it was the coolest thing I had ever seen! I had to get involved. Then, I joined Starbot where I had the chance to work with hundreds of kids that were all building robots. I was hooked! SERVO: How did you get selected to be on BattleBots? Team Busted Nuts Robotics in the Suarez: We had to go through an Witch Doctor and Shaman. pits (L to R: Mike Gellatly, Paul Grata, Jennifer Villa). extended application process that included CAD models, video interviews, and many emails and phone calls. We had been waiting on that final decision for weeks. When I finally got the call from Greg Munson, he briefly congratulated us and then slipped right into the legal information, Witch Doctor without the cover plate and front wedge. timing, stipends, and contracts. That Witch Doctor's Shaman without the was our first glimpse into the asymmetric disk. cover plate. whirlwind we were about to enter. builders: Andrea Suarez, Mike Gellatly, Paul Grata, and SERVO: Tell me about your robot and its weapon. Jennifer Villa. They started off competing on opposing Suarez: Our robot is a multi-bot called Witch Doctor teams, and eventually joined forces. They have become and Shaman. Witch Doctor is based loosely on our great friends, and often travel together to fight robots. Due middleweight by the same name. Its new vertical to job opportunities, the team is now split between Florida, asymmetric disk — shaped like a human skull — is capable of North Carolina, and Texas. Collectively, they have over 45 spinning at over 4,000 RPM. Shaman weighs in at less than years of tournament experience in combat robotics since 40 lbs and has a flamethrower that rivals those on any of 2001. They have competed mostly in the Middleweight the full-size bots. SERVO: How did you pick your robot's name? (120 lb) division, but in the last few years have been very Suarez: Like I mentioned, we have a middleweight active in the Insect weight (150 g to 3 lbs) divisions. named Witch Doctor that we've competed with for years. Here’s what Andrea had to say about her team and We decided to keep the same name since this new robot is their amazing robots. SERVO: What is your profession(s) and does it help you loosely based on the original. Many of our Insect weight when designing and building your robots? robots — Ting Tang, Walla Walla, Voodoo Magic, DeJa Suarez: I am a research and development engineer at Voodoo — also follow this theme. SERVO: How did you design and build it? Biomet Orthopedics, a medical device company. I work on Suarez: During our very limited design period for this developing new implants to help patients that have build, we had planned a trip up to North Carolina to play in sustained a complex fracture as a result of a trauma. Both the snow with our teammate, Paul who had recently moved my job and my hobby require building things that can't there. Late one night, the team took a dip in the hot tub of break under the ultimate test. SERVO: How did you get started in competitive the cabin we had rented and brainstormed all the different robotics? concepts that we wanted to try over the next few hours. Suarez: I was first introduced to robotics at Carrollton We knew we had to keep the design fairly simple since we School of the Sacred Heart when I was 14 years old. The only had a five week build period, but we also wanted it to team of girls had a BattleBots demonstration in the hallway be effective and differentiated. Maybe it was the -12°F

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degree weather combined with the 104°F water, or perhaps it was the adrenaline and the physical exhaustion of our day of hiking and skiing, combined with the notion that we had a chance to be part of something spectacular. The robot design kept evolving exponentially until we knew we had our answer. Once we got back home, we designed many iterations — steel tube frames, welded aluminum frames, different weapon systems — before settling on the final design. Ultimately, it came down to ease of manufacturing. Our team is split up among three states, and we had no personal CNC access. We designed the robot to fit the skills of our two sponsors: Kalamazoo Waterjet and Revolutionary Machine & Design. Kalamazoo Waterjet made our solid S7 Tool Steel weapon and many waterjet components, while Revolutionary Machine & Design did the CNC work on Witch Doctor's frame. We did all the work we could separately, and then our team flew down to meet in Miami to crank out all the finish machining, welding, assembly, wiring, and testing — in just two weekends! It was the most exhausting, intense, and rewarding build I have ever taken part in. SERVO: Multi-bots are not common in most combat events. What led you to choose this configuration? Suarez: We chose a multi-bot design because we were pushing ourselves to try something different. We wanted Shaman to be much more than just a nuisance bot. We wanted it to drive into clamping/lifting robots so they couldn't catch Witch Doctor. We wanted it to create a huge ball of flame around the opponent so Witch Doctor could come in and get its hit. Shaman is all about distraction, manipulation, and fire.

In the arena (L to R: Jennifer Villa, Paul Grata, Andrea Suarez, Mike Gellatly).

Witch Doctor entering the arena (L to R: Paul Grata, just off frame; Andrea Suarez; Mike Gellatly; Jennifer Villa).

SERVO: What did you learn from your BattleBots experience? Suarez: We were initially a bit concerned that the prizes and television crews would affect the behavior of the builders at the competition. It was immediately obvious that the level of support and encouragement between the teams was only heightened by this experience. As always, the BattleBots community is incredible. I can't wait to see what BattleBots does next! SV

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SERVO 09.2015

DIY Animatronics Run Away! It’s ParkerBot! By Steve Koci

The big night is finally here and all your preparations are complete. A light fog smelling of decay drifts through the dimly lit neighborhood as a group of boisterous teenagers descends upon your haunt. Suddenly, out of the darkness charges a creature from their worst nightmares! A huge, hissing spider emerges from its hiding place to attack, sending them screaming and running in fear!

D

oes this sound like a scene straight from a horror movie? It quite possibly does, but it could also be a reality for your Halloween display. Having the ability to control a prop that can directly interact with your guests can provide many exciting scare opportunities. This month, we are going to explore the use of a wireless radio controller to communicate with a remote controlled vehicle. This setup cannot only be used as a Halloween prop, but could provide locomotion for a variety of different characters where direct interaction with guests is desirable. This project has been on my to-do list for quite some time. Others have used a remote control car to deliver a scare, but I wanted to put my own twist to it. My haunt already utilizes several spider scares including a lunging spitting spider, as well as one that attacks from its overhead perch atop my front porch. Being able to deploy one more at just the right time that could actually chase my intended scare victims would be epic! Some of you already have experience working with R/C vehicles and may have many of the components necessary to put this type of project together. This was my first foray into this field, so I had to come up with all the pieces to put the puzzle together. There is a wide variety of controllers available, but I chose to go with a fairly simple model. It did all that was required for this application so I didn’t feel there was any reason to go with a more complicated and expensive

device. The model I chose was the four-channel Tactic TTX410 system from ServoCity (see Resources). It comes with a receiver and is priced under $80. It was the perfect fit for me. Since I was starting from scratch on this build, I could choose a platform that would be just right. I found what I was looking for in one of the new robot chassis also put out by ServoCity. When I saw the robot kits, I was convinced that I could find one which would satisfy all of my requirements. They offered large platforms that would accept the Actobotics components I wanted to add, and the supplied motors and tires gave them great performance over a variety of terrain. If having a large spider chase you down the street wasn’t enough, I also wanted to be able to raise its head. In order to accomplish this, I needed to have something that was both controllable and provided the necessary torque to lift the head of the spider. Although a servo would give me the control I wanted, it lacked the necessary torque to lift the spider I had planned on using for this project. This led me to the decision to go with a linear servo — something I have wanted to try since first discovering them. I also wanted to add moving pincers to its mouth. Once again, I found just what I needed from ServoCity as they have several different models of grippers to choose from that would be perfect for my needs. These use a standard servo and can also be activated using the wireless controller. SERVO 09.2015

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DIY Animatronics Post comments on this section and find any associated files and/or downloads at www.servomagazine.com/index.php/magazine/article/september2015_Koci.

This is How We Roll

Figure 1. The fun begins with the chassis parts from ServoCity.

The base platform I selected for this project was the new Scout robot kit from ServoCity. Although it does come unassembled with many parts (Figure 1), the build was quick and smooth thanks to the thorough online instructional video. A complete tool set isn’t required as it only takes a couple of hex keys to assemble. After a constructive conversation with Kyle — one of the fine ServoCity techs — we decided to use Pololu motor controllers (Figure 2). Two were needed: one for the right side motors, and another for the left side motors. I also installed the gearmotor input power boards to the motors. These make the swapping of motors and changing of polarity (if necessary) a simple task. Everything else was linked together using a variety of wire connectors and extensions.

Figure 2. Pololu motor controllers and receiver added to chassis.

I’ll Have My People Call Your People Normally, I would not consider incorporating a wireless controller into one of my designs. However, having the ability to control a character in real time has its advantages. I would be able to choose my intended target and focus on those that I felt could handle the extra scare attention. I do have plenty of young children that visit my haunt and I feel this type of prop may be too intense for some of them. Now, I could keep the spider in hiding until a more suitable victim came along. The controller was easy to set up using the Simple Motor Controller program provided by Pololu. I just had to go in and change the default setting from serial/USB to RC, and then go through the Quick Input setup. As soon as that was completed, it was off to the races! Once I had the frame built and the motors running with the controller, it was time to take it for a spin. I rushed outside and quickly had it speeding up and down the sidewalk. I was excited to see that it performed exactly as I had

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DIY Animatronics

Figure 3. Head lifter and gripper mechanisms are complete.

planned. Of course, I still needed to add the lift and gripper mechanisms and the spider body. I made a quick calculation of the combined weight of the yet-to-be-added components and loaded down the chassis with the equivalent in lead. It was now time to test it again to confirm that all was still on track. I pushed the throttle forward expecting it to speed down the sidewalk once again, but was sorely disappointed! It moved, but even a toddler could outrun it now! It was time to return to the drawing board and attempt to resolve the speed issue. I was so pleased with the speed and agility of the bare platform that I didn’t want to sacrifice it. Something had to give.

We Need More Power, Captain! I concluded that I had a couple of options open to me. Either add larger and more powerful motors or significantly lighten the load. My unrealistic expectations regarding the ability of my chosen RC platform to carry all the extra weight proved I still had plenty to learn when working with this new base. I now have even more respect for the BattleBot designers that can include all that steel and weaponry and manage to have a quick robot! I still believed that the Scout robot was up to the task, but I would need to greatly reduce my design in order to control the amount of weight I expected it to carry. It was time to scale back and cut out all the spider’s fat! The original plan was to use one of the many spiders I had on hand in order to save some money and speed up the build process. The spider I chose was very large and menacing looking, which provided the effect I was after. However, it included some steel reinforcements which added considerable weight. It also had a soft foam body

Figure 4. Primed and painted black awaiting a body.

which would make it difficult to install around the mechanics without interfering with their operation. I then conducted an extensive and fruitless Internet search to try and find a suitable replacement. When I came up empty, I decided to try and recruit my wife to help me construct a custom model. This turned out to be the perfect solution to my problem! Before we started the construction of the spider, I took another look at my plan to use a linear servo to lift the front of the arachnid. If I was going to go with a lighter one, was there another option? I’ve had great success using the servo powered gearboxes from the Actobotics line at ServoCity for my articulated bodies. I figured it would have the necessary torque to raise the body, now that I’d replaced my original spider with a much lighter one. I mounted it up, attached some weight to the lifting arm, and gave it a test. It handled the load like a champ, with the added bonus of requiring much less juice — allowing my batteries to last significantly longer. It was now time to build a framework to attach the channel to which the gearbox and gripper would be affixed. I started with two pieces of 12 inch channel and cut them down until I was happy with the proportions. These were simply connected with a hinge, giving it a very wide range of motion. Connecting the servo horn on the gearbox to the upper channel was easy once I had the mounting point selected by using 6/32 threaded rod and ball linkages. I then built a protective structure around the servo to allow the body to be attached without interfering with the mechanism. The gripper kit was a snap to assemble (again, thanks to the easy-to-follow video instructions). After only a few minutes, it was ready to pinch away (Figures 3 and 4). SERVO 09.2015

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DIY Animatronics

Figure 5. Foam body with cutout for the lift mechanism.

The lift and gripper servos were controlled by the left joystick on the controller, while the wheels were directed with the right joystick. I then took some white Styrofoam and shaped a head and body to fit the exact dimensions required. The interior of the body (Figures 5 and 6) needed to have a large cavity carved out to allow it to fit down over the head lifting mechanism. I cut some chain link stretching wire for the legs and secured them to the channel with ProPoxy 20. My wife then fashioned the fur to cover the body and wire legs which gave it just the right look. The addition of a couple of red LED eyes gave it a sinister stare and greatly enhanced the overall effect. I also

Figure 6. It looks like a snowman! I need some fur!

added a pair of green LEDs to the pincers so their motion could be seen, and another pair of red LEDs underneath the chassis for a spooky glow. I simply tied into the battery pack for the wireless receiver leaving me with one less thing to worry about. Keep it as simple as possible and there are less chances of something going wrong (Figure 7).

I Can’t Hear You

SPIDER PARTS Quantity 1 2 2 1 1 1 2 1 1 1 1 1 1 3 2 2 1 1 1 3 4 2 4 2 2 1 1

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Description Scout Motor controller 9.6V battery Wireless controller HS-485HB servo Hinge 12” channel HS-5685MH servo & gearbox 6/32 threaded rod Gripper Battery adapter Battery charger Servo linkages Screw plate Servo leads Servo extensions Clamping hub Servo lead Screws Channel mount Input boards JST extensions JST extensions JST leads Channel bracket A Aluminum beam (package of 2) Y harness

SERVO 09.2015

ServoCity Part # 637138 605060 HCAM6367 TACJ2410 33485S 585644 585454 SPG5685A-CM 98847A007 637094 FBL-TAM 44165 585432 585430 MM2204S SE2218S 545352 FSL-2206S 632108 545360 605118 607016 607010 JST-22M 585484 585416 SY2424S

No self-respecting spider would be running around in silence! The final step was to take it up one more notch by adding an audio track. Now, I know that spiders don’t really make many sounds, but Hollywood has already primed the public to expect it and I wanted to deliver! I was able to find a variety of insect sounds from a free “web” download site (see Resources) that

RESOURCES ServoCity — www.servocity.com Electronics123 Audio Board — http://tinyurl.com/pbdjmy6 Pololu Simple Motor Controller — http://tinyurl.com/osmoz67 Sound Downloads — http://tinyurl.com/puavabc Audacity Audio Editor Download — http://tinyurl.com/qmn3q My website — www.halstaff.com

DIY Animatronics Figure 7. Fur and LEDs installed and ready to go hunting!

allowed me to select several different sounds and combine them to make the track. I used a simple recorder (Figure 8) from Electronics123 (see Resources) which includes a speaker, triggers, and a battery pack. It was then a simple process to load the completed track which I’d prepared in Audacity (see Resources). In order to save weight, I decided to stick with the tiny onboard speaker that came with the player instead of adding a set of speakers. The sound quality is not great but for my purposes, it works. This player includes a repeat function, so I just trigger it and away it goes.

It is Alive! I had a great time bringing this guy to life (Figure 9). (The link to the completed video can be found at the article link or on my website.) Although not an overly complex project, it satisfied my goal which was to explore the technology to determine how useful it would be for our purposes. It allowed me to try out some new techniques and play with some cool previously overlooked toys. I became familiar with the electronics and now have a better understanding on how to best put a system together. Ultimately, we’ll be using the wireless controller to do some live puppeteering of a character — just like they do when filming movies. Another project I’d love to try is to affix a gripper attachment to an articulated arm. I would then control it with the wireless transmitter to hand out candy. Combine that with a microphone that controls the jaw of the character and I could talk to the trick or treaters as I hand out the Halloween candy. Now, that would be an interactive character! After playing with this, I can understand how building fighting robots can become so addicting. It’s a whole lot of fun! SV

Figure 8. Basic audio player from Electronics123.

Figure 9. Looking spooky and on the prowl.

SERVO 09.2015

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a n d

g{xÇ Now

by Tom Carroll [email protected]

What We've Learned from the DARPA Robotics Challenge On June 5-6, 2015, the DARPA Robotics Challenge (DRC) Finals were held at the Los Angeles County Fair Fairplex in Pomona, CA. Thomas Messerschmidt wrote an excellent article about the competition in the August issue of SERVO. I covered some of the pre-DRC information back in the March issue, with a bit of emphasis on the history of DARPA's challenges. The rules have since been changed and the DARPA Robotics Challenge is now — as they say — history. read with great interest the many media postings and reports about this latest DARPA competition. There were some very amazing accomplishments made by the many robot entrants, and there were some unfortunate failures that occurred during the many competitions. The event was amazing for robotics professionals, as well as the public. Many interesting robotics

I

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exhibits from schools and robot manufacturers around the complex helped make the event a unique experience for everyone attending. The DRC Finals made more media headlines than any other technical subject in June — both in a positive and negative way. It was the negative slant in many of the articles and newscasts that disappointed me the most. Yes, most of the robots fell over while getting out of the vehicles and/or while traversing simulated rubble. I read that one man described the walking robots as “sure footed as toddlers.” At least a dozen of the contestants fell over — some more than once — but after repairs, most were able to continue in the competition. They and their teams were all amazing in their performances, despite the few problems. The press also jumped on the tragic incident where a robot installer was accidentally killed in Germany at a VW plant. Does the public — and even the media — truly understand just how complex both the robots and the challenges were? Or the progress that is being accomplished in robotics technology? The US Defense Advanced Research Projects Agency (DARPA) formed the idea of the DRC in 2012, after their successes with the autonomous vehicles in the earlier Grand Challenges. The Robotics Challenge was inspired by the Fukushima Daiichi nuclear disaster in Japan back in 2011. The idea was to develop robots that can aid emergency responders in disaster recovery efforts where areas

are unsafe for humans to enter. Robots were used in the early days of the Fukushima disaster recovery process, but it became obvious to the various recovery teams that there had to be a better robotic solution to the clean-up process.

Earlier DARPA Grand Challenges Before I delve into this latest DRC competition, let us remember our earliest space endeavors in the late ‘50s and early ‘60s. Even after Kennedy announced our intent to go to the moon by the end of the ‘60s, rockets still blew up on the launch pads. Would you want to ride into space on the top of a converted missile after watching an identical rocket explode a few months earlier? Even after the Mercury and Gemini programs had been successfully completed, Apollo 8 astronaut, Bill Anders later revealed to me just how dangerous his first manned Saturn V/Apollo flight in 1968 to the moon really was. Many knowledgeable NASA personnel had doubts that the three men would come back alive, but this was a ‘show off’ flight to impress the Russians. So, the US had to try it. In the very next year, we landed two Americans on the moon — a technical achievement that has not been repeated since the last lunar flights 43 years ago in 1972. Progress marches forward. Let’s look back at the earliest DARPA Grand Challenge. In March 2004, DARPA set up a 150 mile off-

Advances in robots and robotics over the years.

Post comments on this article at www.servomagazine.com/index.php/magazine/article/september2015_ThenNow.

Figure 2. Stanford’s entrant won first place in the 2005 DARPA Grand Challenge.

Figure 1. Carnegie Mellon’s Red Team covered the greatest distance in the DARPA 2004 Challenge.

road course near Barstow, CA and invited 15 teams to attempt to autonomously drive the course with driverless vehicles. A $1 million prize was offered for the winner, but the farthest any vehicle managed to travel was 7.32 miles. Carnegie Mellon University’s Red Team’s entry shown in Figure 1 made it the farthest, however, no prize was offered and some considered the event a failure. Fortunately, DARPA’s Figure 3. Carnegie Mellon’s Tartan Racing won the 2007 Urban Challenge. powers-that-be convinced the government to allow them to Base in Victorville, CA. The entrants continue with competitions and the had to complete the course in less next event in October 2005 had five than six hours — all while obeying finishers on a 132 mile course near normal traffic rules and regulations, the California/Nevada border. dodging obstacles and other vehicles The fifth finisher — a huge truck randomly merging onto the course. called the TerraMax from Oshkosh Carnegie Mellon’s Tartan racer Truck Corporation — spent the night shown in Figure 3 won this contest parked and finished in 12 hours — with a time of four hours and 10 over the allowed time limit. The minutes utilizing a modified Chevy winning Stanford University team’s Tahoe. vehicle shown in Figure 2 finished in Going from a handful of vehicles six hours and 54 minutes. that ran into fences and fell off the Now, that is progress over the courses in the early contests to first contest! We learned quite a bit supremely polished vehicles that about autonomous cars from these successfully traversed a simulated DARPA Challenges. urban road environment is another Jumping ahead two years in great leap of progress! November 2007, DARPA’s third These early DARPA Challenges challenge was on a 60 mile closed prove that the old adage “Try and try course at the former George Air Force

again” can result in some amazing developments.

The DARPA Robotics Challenge is Only a First Step The DARPA series of challenges — from autonomous cars that I mentioned earlier to robots — was a very smart approach for a government agency. Rather than paying bidding companies a lot of money to possibly develop a needed technology solution, DARPA’s approach was to specify what technological challenge they needed figured out and allow highly competent groups to solve the challenge with a contest. The winner would ‘walk away’ with several million dollars and DARPA would own the rights to a very nice piece of technology. It was a win–win scenario for all. With the Japanese reactor damage and resulting environmental mess mentioned earlier clearly in mind, DARPA set forth to develop the DRC in hopes that talented groups around the world would enter into a friendly competition to develop a robot that could enter and assist with the cleanup of disaster areas such as SERVO 09.2015

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Figure 4. Team Trooper’s Atlas driving in the passenger seat. Photo courtesy of the IEEE Spectrum site.

Figure 6. KAIST’s HUBO at the door on Day 2. Note the wheels on the knees and feet.

people, and 488,000 people were temporarily or permanently displaced from their homes. Yes, there was a large loss of life and many homeless survivors. However, it was the damage to the nearby nuclear power plant that caused the most difficult cleanup and recovery process. Reactor cooling pumps failed, ocean water overflowed barriers and damaged standby power generators, and extreme radiation prevented humans from entering many locations. My article last June about the unique situations that created this unmanageable scenario only touched on a small part of the overall disaster.

Figure 5. Carnegie Mellon's Warner had to slide through the door sideways.

the Fukushima site.

Fukushima Daiichi Nuclear Disaster Let’s look back at the 2011 earthquake disaster that spurred DARPA’s decision to have this latest challenge. On March 11, 2011, one of the most powerful and damaging earthquakes on record hit the east coast of Japan. There is not a country on earth that is more primed for earthquake and tsunami disasters than Japan, but this powerful shaker caught them unprepared. At 2:46 in the afternoon, the Prefecture of Fukushima was struck with an earthquake that measured 9.0 on the Richter scale. The quake and resulting tsunami killed over 18,500

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The DRC Rules and Tasks for the Robot Competitors DARPA pretty much drove most

of the competing robots to be bipedal humanoids for a good reason. Most humanly built areas that might be in a disaster area are designed to be used by two-legged folks. Mobile vehicles, stairs, doorways, door handles, valve handles, power switches, handheld portable power tools, and similar things are designed around standard human configurations and manipulative capabilities. The following eight tasks below were what these robots faced in the 2015 competition. Each task was scored as one point: 1. Get in and drive a vehicle over a short course. The vehicle in Figure 4 is the same Polaris Ranger ATV that was used in the Trials, though the roll-bar roof was removed to accommodate the taller robots. Some robot teams decided to have their entrants walk the course rather than drive it.

2. Egress from a vehicle (get out of the vehicle). This was far more difficult for some of the robots. 3. Open the door of a building and travel through the opening. The door opened inward (away from the robot). The door did not include a threshold. Once fully opened, the door remained open. Some of the robots had to go through sideways as in Figure 5 because they were too wide with their arms and body. There were originally three types of doors. 4. Open a valve (similar to one of the three valves in the Trials). DARPA used a circular valve handle with a diameter of about eight inches (20 cm). The valve rotated counterclockwise. 5. Use a rotary-blade ‘drill’ to cut a hole in drywall. A circle was drawn on the wall, approximately eight inches (20 cm) in diameter. The cutting operation had to entirely remove all wall material from the small circle, but within a larger designated circle. 6. There was a surprise manipulation task that was not disclosed until the Finals. The task required manipulation and no mobility. The ‘surprise’ was pulling out a plug and putting it back into another socket. This is not as easy as it might seem. The plug had to be oriented correctly and aimed into the receptacle — a task even us humans sometimes have difficulty with. 7. Traverse rubble. Either cross a debris field by moving the debris (pipes and boards) or walk across a random pile of cement blocks, similar to the Trials. Many robots tripped up on the uneven and rock surfaces of the blocks. The original seventh task was to

Figure 7. The KAIST-4 lower legs showing the powered wheels and swivel caster arrangement.

mate a hose to a spigot. 8. Climb a short set of stairs (fewer steps and less steep than in the Trials). The stairway had a handrail on the left side and no rail on the right. Penalties assessed in the competition included a 10 minute forfeiture if the robot fell and had to be righted by its team. The robot could right itself and continue on, but most falls required human assistance. A 10 minute penalty was also assessed if a robot could not complete a task and had to be ‘reset’ to the beginning of it. I dare say that most healthy human adults faced by an identical disaster scenario might have completed these tasks in a few minutes, but that was not the point of this challenge. Toss in high radiation, volatile chemicals, high temperatures, escaping steam, and other hazards — let’s send in the robots! Some tracked robotic vehicles loaned to the Fukushima Daiichi nuclear disaster site by the US and other countries were partially successful, as well as quickly developed robots made in Japan shortly after the disaster. However, many officials felt that the disaster scene really needed humanoids with dexterous arms and hands connected to bodies that could quickly climb and traverse the rubble at the site.

Figure 8. KAIST HUBO opens a valve during the competition.

The DRC Contestants The charts shown on pages 78-79 illustrate the wide variety and designs of robot contestants that were prepared for the DRC. Six of the teams used the pre-made million-dollar plus Atlas supplied by DARPA for their entries. The original Atlas robots used a tether for external power. The reason: Large robots suck power — lots of power — and the tethers also served as emergency suspension cables to save the robots from accidentally crashing to the floor in tests. The DRC competitors had heavy internal power battery packs — a disadvantage when it came to balancing when walking. Built by the noteworthy Boston Dynamics — builder of the amazing Big Dog and other walking robots designed to be used by the military — these six foot, 330-400 pound robots with 28 hydraulically powered joints were derived from the earlier PETMAN. MIT’s Computer Science and Artificial Intelligence Lab heavily influenced the Atlas software design, and their sixth place finish Atlas had 650,000 lines of code in their robot. Boston Dynamics technology has long been the world leader in the dynamic stability and control of walking robots. Other entries were custom designed by their respective team members, such as the HUBO KAIST shown in Figure 6 entering the SERVO 09.2015

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Figure 11. Team Tartan Rescue’s CHIMP attempting the drill and drywall task. Figure 10. The Team IHMC Running Man robot steps out of the Polaris. It eventually took second place.

doorway, which — by the way — was the winner of the $2 million first prize with a time of 44:28 and eight points. Note the excellent design feature in Figure 7 that used wheels on the knees and feet to roll about rather than walking. Figure 8 shows the KAIST HUBO manipulating the valve handle. No, it is not double-jointed at the knees but rather swivels at the waist. At an inch shorter than six feet and 176 pounds, it is fairly close to a typical human being in size and weight. KAIST’s humanoid bipedal robot expertise arises from the development of HUBO shown in Figure 9 — not quite as well known

Figure 9. Highly successful HUBO humanoid.

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as Honda’s Asimo, but every bit as capable.

The Team IHMC robot — Running Man shown in Figure 10 — came in

second place with a time of 50:26 and the full eight points. The Atlas style robot was a crowd pleaser and happened to stumble and fall on the concrete blocks. The third place winner with a time of 55:15 and eight points — the CHIMP (CMU Highly Intelligent Mobile Platform) from Team Tartan Rescue — is shown in Figure 11 and reminds me of a red chimpanzee with belt sanders on its elbows and feet. Actually, the robot from Carnegie Mellon University is an incredibly well designed robotic platform that is perfectly suited for rescue work. CMU has always been at the forefront of robotics research and was a winner at the original DARPA Grand Challenges. Like the KAIST HUBO, the use of wheels made for a very stable competitor. The Team NIMBRO Rescue from Germany shown in Figure 12 is a wheeled robot that was a bit on the light side at 130 pounds, but quite capable in maneuvering about a disaster site and climbing stairs. It was a good example of a DRC robot that was not a bipedal humanoid.

Figure 12. Team NIMBRO Rescue’s robot from Germany at the ‘surprise’ task.

worked years in the perfection of these entries. Failure is the requirement for success. As Thomas Edison is quoted on his many attempts to find a durable filament for his light bulb: “I have not failed 10,000 times. I have not failed once. I have succeeded in proving that those 10,000 ways will

not work. When I have eliminated the ways that will not work, I will find the way that will work.” His statement emphasizes just how difficult it is to attain ultimate progress. This applies to robot design, as well as light bulbs. Progress might be slow but it is inevitable for those who strive for improvement. SV

DRC Robot Contestant Guide courtesy of the IEEE Spectrum site.

Final Thoughts Let us not direct all of our thoughts and conclusions on the pitfalls and missteps of the very capable DRC robotic contestants, but rather look at the competition as a key step in the development of a useful robot to assist humans in the difficult and unpredictable cleanup scenario of a natural or manmade disaster. Think about the amazing progress we have made in the development of autonomous cars for our highways in the last decade. Having designed and worked on robots to assist space borne operations, I can sympathize with the team’s embarrassing falls, and at the same time, applaud their stunning accomplishments. I did not show any photos of the fallen robots on purpose; why embarrass team members who SERVO 09.2015

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