Tạp chí Servo
Vol. 6 No. 1 SERVO MAGAZINEZENO•SUPER STEPPER DRIVER•SPACE ROBOTICS•NEW LIFE FOR ARTI ONE January 2008 Cover.qxd 12/6/2007 8:50 AM Page 1 Full Page.qxd 12/5/2007 3:20 PM Page 2 Full Page.qxd 12/5/2007 2:19 PM Page 3 4 SERVO 01.2008 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; cpcreturns@servomagazine.com Departments 06 Mind/Iron 21 Events Calendar 22 New Products 23 Robotics Showcase 66 Robo-Links 76 SERVO Webstore 82 Advertiser’s Index Columns 08 Robytes by Jeff Eckert Stimulating Robot Tidbits 10 GeerHead by David Geer Zeno — The First Complete Character Robot 14 Ask Mr. Roboto by Pete Miles Your Problems Solved Here 61 Twin Tweaks by Bryce and Evan Woolley More Than Meets the Eye — the Mighty Morphing V-Bot 67 Different Bits by Heather Dewey-Hagborg Neural Networks for the PIC Microcontroller Part 4: Self-Organizing Maps 71 Robotics Resources by Gordon McComb Small Brains for Your Bot 75 Appetizer by Gerard Fonte Terms of Endearment 79 Then and Now by Tom Carroll Robots Take to the Air PAGE 24 TOC Jan08.qxd 12/5/2007 11:16 AM Page 4 01.2008 VOL. 6 NO. 1 SERVO 01.2008 5 ENTER WITH CAUTION! 24 The Combat Zone MEET THE MIGHTY MORPHING V-BOT/pg 61 32 The Super Stepper Driver by Fred Eady Build an intelligent stepper motor controller from scratch that’s based on the Allegro MicroSystems A3979. 38 Compute Square Roots Fast by Tim Paterson Square roots have a number of possible applications in microcontroller systems. 42 GPS by Michael Simpson Part 4: A closer look at the interface needed for each of the GPS modules covered in this series. 49 Space Robotics by Fulvio Mastrogiovanni This article focuses on the entire control loop that’s used to allow a rover to safely navigate on Mars using information from Earth. 54 C Programming for Microcontrollers Made Easy by Sam Christy This new, no-cost online system can cut start-up time from hours to minutes. 56 Reviving a Showbot by Robert Doerr Give ARTI ONE a new lease on life. Features & Projects TOC Jan08.qxd 12/5/2007 11:16 AM Page 5 Published Monthly By T & L Publications, Inc. 430 Princeland Court Corona, CA 92879-1300 (951) 371-8497 FAX (951) 371-3052 Product Order Line 1-800-783-4624 www.servomagazine.com Subscriptions Inside US 1-877-525-2539 Outside US 1-818-487-4545 P.O. Box 15277 North Hollywood, CA 91615 PUBLISHER Larry Lemieux publisher@servomagazine.com ASSOCIATE PUBLISHER/ VP OF SALES/MARKETING Robin Lemieux display@servomagazine.com EDITOR Bryan Bergeron techedit-servo@yahoo.com CONTRIBUTING EDITORS Jeff Eckert Tom Carroll Gordon McComb David Geer Pete Miles R. Steven Rainwater Michael Simpson Kevin Berry Fred Eady Robert Doerr Sam Christy Tim Paterson Gerard Fonte James Baker Chad New Don Hebert Bryce Woolley Evan Woolley Heather Dewey-Hagborg Fulvio Mastrogiovanni CIRCULATION DIRECTOR Tracy Kerley subscribe@servomagazine.com MARKETING COORDINATOR WEBSTORE Brian Kirkpatrick sales@servomagazine.com WEB CONTENT Michael Kaudze website@servomagazine.com PRODUCTION/GRAPHICS Shannon Lemieux Joe Keungmanivong ADMINISTRATIVE ASSISTANT Debbie Stauffacher Copyright 2008 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. INFRASTRUCTURE A fundamental aspect of robotics is that the application domain can range from ocean beds and table tops to the nooks and crannies of extraterrestrial dunes. It’s no coincidence that the techniques and technologies described in the article featured in this issue of SERVO can be applied to virtually any application areas. However, if you have a particular interest in space exploration, then you’ll find Fulvio Mastrogiovanni’s article, “Space Robotics,” of particular note. Fulvio, a PhD candidate from the Mobile Robotics and Artificial Intelligence at the University of Genova, Italy, offers a focused consideration of control theory applied to the practical challenges presented by the NASA Mars Explorer Rover mission. The article also hints at an often ignored and poorly understood aspect of robotics — that of infrastructure. Space exploration and transport, together with development of more traditional military gear, are responsible for many of the innovations in sensors, software, and platform designs that trickle down to civilian robot developers. However, even if you have access to the components and algorithms used by NASA engineers, you’d probably find it impossible to develop a robot that even approximates the abilities of the impressive Martian rovers. The missing ingredient is infrastructure — the robots, conventional tools, and processes used to develop the vehicles and robots destined for space. Consider the array of advanced robotics used in the construction and testing of the shuttle’s external tank. The shuttle’s external tank, which has a length of 55 feet and diameter of 28 feet, is fabricated at the Michoud Assembly Facility, near New Orleans. When I toured the facility, I was amazed at the robots and other automated equipment required to achieve the tolerances necessary for space flight. In particular, I witnessed a fully assembled fuel tank mounted horizontally on a motorized spindle in a way that enabled robots to apply insulating foam to the aluminum-lithium tank. I tried to imagine the control systems and motors necessary to rotate the 58,000 lb tank and maintain a precise coating depth. Although I haven’t seen it first hand, I assume that the robotic equipment used to create the multi-stage Boeing Delta II that transported the Martian rovers is just as impressive. Sam Christy’s article on programming for FIRST controllers and Tim Paterson’s article on square roots illustrate a key ‘invisible’ component of the infrastructure required to develop robots. If you’re like many roboticists, you probably have a drill press, soldering iron, a few boxes of spare parts, perhaps a library of reference texts, and a PC. To the uninitiated, the PC may be simply another artifact in your workshop. However, if you’re involved with developing control loops, machine vision, wireless communications, or other computational tasks, then your PC may be your primary development tool. In this regard, traditional tools and components often fail to capture the enormity of effort, planning, and time that goes into developing a robot. If you’re new to robotics, then you’re just beginning to appreciate the depth and breadth of your development infrastructure (or lack of it). Whether you’re primarily involved in developing pneumatic weapons for battle bots or vision recognition algorithms for a commercial robotic platform, you’ll soon discover that a development infrastructure is a prerequisite for efficient, unencumbered robot development. At the start of my robotics career, I invested almost a year of effort developing a flexible infrastructure. The major components include: • Drill Press and Bit Assortment • Vise • Work Bench • Dremel and Accessories • Dual-Trace Digital Oscilloscope • Multimeter • Regulated Power Supplies (3) • Lamp • Glue Gun • Heat Gun Mind / Iron by Bryan Bergeron, Editor Mind/Iron Continued 6 SERVO 01.2008 Mind-Feed Jan08.qxd 12/4/2007 2:39 PM Page 6 • Air Compressor • Hand Tools • Glues and Adhesives • Nut and Bolt Library • Clamps • Cables, Wire, and Shrink Tubing • Connectors and Pins • Soldering/Desoldering Station • R/C Unit • Nibbler Tool • PC • Software (Schematic generation, simulation, compilers) • Sensors (US, IR, motion, etc.) • Microcontrollers (STAMP, PICs, ATMEL) • Storage Bins • Breadboard System • Multi-drawer Tool Chest I’m still working on the infrastructure, but at a much lower level. So, how do you go about building an infrastructure? If you’re fortunate enough to be financially well positioned, then the anticipatory approach is a viable option. Assuming that you can accurately anticipate your upcoming needs, then you can assemble an infrastructure within a few weeks. Even with equipment in hand, you’ll need several weeks to learn how to operate and apply your new hardware and software. At the other extreme is the as-needed approach, which entails purchasing tools and test equipment on an as-needed basis. While easy on the pocket, this approach often results in a loss of momentum. Stopping a project midway to await delivery of a drill or torque wrench and then learning how to use the device can derail an otherwise focused project. There is also the defocusing associated with taking time to identify the best oscilloscope, drill press, or other item. The two approaches aren’t mutually exclusive. For example, I use a hybrid approach in which a few major purchases — drill press, multimeter, hand tools, and oscilloscope — are added to as needed. I’ve learned the hard way that when you build an infrastructure, buy the best that you can afford. Don’t be lured by an inexpensive hand tool or soldering iron that will satisfy your current project. Instead, try to anticipate what you’ll need over the next five years. It costs more to buy a cheap tool and then a more expensive tool a few months later, than to buy the right tool to begin with. I’m a big fan of eBay where — if you’re patient enough — you can find good deals on equipment that might otherwise be out of your reach. Another option is to outsource your infrastructure by joining a well-stocked robotics club. For modest dues, you can have access to a supportive infrastructure that may prove invaluable to your success in robotics. A related approach is to extend your infrastructure with external services, such as laser cutting. I use Pololu Robotics and Electronics (www.Pololu.com) for laser cutting on large projects. Outsourcing can be expensive, but it allows you to focus on what you do best. As a word of warning, as you construct your infrastructure, remember that it’s tempting to use robotics as an excuse to amass a huge collection of fantastic tools and equipment. This is fine if your intent is to collect tools. However, if your goal is to produce functional robots, then do your best to avoid the seduction of gear. 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OSMC 6 6 6 6 Monster power! 14-50V 3.15 x4.5”x1.5” 3 wire interface 160A! ” www.robotpower.com Phone: 253-843-2504 sales@robotpower.com Scorpion HX 6 6 6 6 Dual (6A pk) H-bridges fwd-only channel 5V - 18V 1.6“ x 1.6” x 0.5” 2.5A 12APlus $79.99 Scorpion Mini 6 6 6 2.5A (6A pk) H-bridge 5V - 18V 1.25“ x 0.5” x 0.25” $119.99 Scorpion XL 6 6 6 Dual H-bridge 5V - 24V 2.7“ x 1.6” x 0.5” 13A 45A Peak! 6 6 6 6 6 6 6 14V - 50V - Dual H-bridges - 150 Adjustable current limiting Temperature limiting Three R/C inputs - serial option Many mixing options - Flipped Bot Input Rugged extruded Aluminum case 4.25" x 3.23" x 1.1” 80A A+ Peak! $29.99 $399 Introducing Dalf 6 6 6 6 6 6 6 Closed-loop control of two motors Full PID position/velocity loop Trapezoidal path generator PIC18F6722 CPU C source for routines provided See Giant Servo Mode! www.embeddedelectronics.net $250 MADE IN THE USA H-bridges: Use with Dalf or with your Micro/Stamp Simple-H 6 6 6 6 6-28V 25 2.25 x2.5 x0.5” 3 wire interface current & temp protection A! ”” $79 SERVO 01.2008 7 In re-reading my December 2007 Robotics Resources column, I spotted a small error regarding the light wavelength of the laser diodes used in DVD players. Most commercial DVD players use 650 nanometer (deep red) laser diodes, rather than the 780 nanometer (infrared) laser diodes common in CD players. Gordon McComb Robotics Resources Mind-Feed Jan08.qxd 12/4/2007 2:40 PM Page 7 8 SERVO 01.2008 Goodbye E-Harmony, Hello Bot-Harmony You may have noticed (or tried not to notice) that some robots are becom- ing a lot more lifelike and even alluring. One example is Dion, a Chinese babe who is said to mimic all sorts of human features, including facial expressions, skin temperature and elasticity, breath, and heartbeat. According to the manu- facturer, she can even be built to resem- ble the specific person of your choice. Another deliberately seductive mechanism is Actroid DER2, developed at the University of Osaka and manufac- tured by Kokoro Co. This one is designed “to play an active part for many occasions as a chairperson with fluent narrations and booth bunny.” You can even rent her for a five-day outing for $400,000 yen (about $3,500 US). I didn’t locate any specific infor- mation about how intimate these yum- bots are designed to be, but if you are presently settling for a partner who has to be inflated for each romantic encounter, you might be interested in a recent book by AI expert David Levy. The good news is that it someday will be common for people to marry and have sex with robots. The bad news is that Levy doesn’t expect it to be legal and acceptable until about 2050. He also predicted that Massachusetts will be the first to legalize it. If you want to follow that line of logic, pick up a copy of Love and Sex with Robots: The Evolution of Human-Robot Relationships, published late last year by HarperCollins (www. harpercollins.com). The hardcover edition will cost you $24.95, or you can get the e-book for $19.95. Arm Inspired by the Real Thing Ever since the Barrett Hand — a three-fingered manipulator used extensively by NASA — was introduced in 1997, mechanical arms have grown more dexterous and complex, but still haven’t looked or operated that much like the human counterpart. But an eerily lifelike one, even without any skin covering, has been brought to us by Germany’s Festo Corp. (www.festo.com). The company is known primarily for its pneumatic and electromechanical systems, components, and industrial controls. But perhaps its most interesting accomplishment is the creation of Airic’s Arm. Based on the real thing, it even has metal versions of the radius and ulna, the metacarpals, and the shoulder and shoulder blade. One big difference, how- ever, is that it is powered by 30 of Festo’s “Fluidic Muscles,” which are tubes of elastomer reinforced with aramide fibers. When you fill one with compressed air, its diameter increases and its length shortens, thus creating movement. This actually gives Airic an advantage over the rest of us: When the arm contracts, it doesn’t require any additional power to stay contracted; that is, it can lift some- thing and hold it in place indefinitely. Festo intends to further develop the system by adding vision and tactic sensors and maybe even giving it a neck, a back, and a hip. A short video of the thing in action is presently at www.youtube.com/watch?v=tVg6 xKHJKY4. Feeding Robot for the Disabled On a more specialized level is the My Spoon feeding robot manufactured in Tokyo by SECOM Co., Ltd. Designed to allow victims of spinal cord injuries, muscular dystrophy, and other disabili- ties to feed themselves without a care- giver’s assistance, it offers interchange- able controllers and utensils, and a selection of operating modes to accom- modate different disability levels. It’s not quite up to the flexibility of a humanoid hand in that foods must be served from specific divisions of a meal tray, and they must be in bite-sized pieces. Both users and therapists seem to be praising its effectiveness, and it was even nominated as a finisher in the Top 10 Robots listed by Japan’s Ministry of Dion, from Beijing Yuanda Super Robot Technology Co., Ltd., and Actroid, from Kokoro Co., Ltd. Airic’s Arm, perhaps the most realistic robotic arm yet. Photo courtesy of Festo Corp. The My Spoon™ feeding apparatus. Photo courtesy of SECOM Co. by Jeff Eckert Robytes Robytes.qxd 11/30/2007 11:19 AM Page 8 Economy, Trade, and Industry. No price is given on the company’s website (www.secom.co.jp/english/index.ht ml), which probably indicates that it will run you a pretty nice chunk of change. But the main idea is to give the user a greater sense of independence, which is not a bad thing. And it could probably be fitted with a nice demitasse spoon, making it useful for a fair number of Hollywood actors and pop stars . Creeper Checks Structural Integrity Quite often, even creepy little robots on tracks can cost an amazing amount of money. For example, it was reported that the US Army recently ordered 40 PackBots from iRobot (www.irobot.com) at a cost of $8.8 million, or $220,000 each. It is therefore interesting that Sanyo appears ready to introduce a model that is rumored to be priced at a paltry one million yen (about $8,900). Sure, the military machines are more heavily equipped and hardened for rough duty and, sure, we’re comparing horses to ponies. But still, at about 1/25th of the cost . In any event, details are spotty, but Sanyo's new machine — so far, rather generically named the Underfloor Robot — is designed to scamper around underneath potentially crumbling office buildings, apartments, and other places that may be suffering from structural damage. It runs about two hours on a charge, performing visual inspections and beaming back video of whatever it finds. It is equipped with a zoom lens for getting down to details and will automatically create reports and measure the distance between objects. Other specs include dimensions (L, W, H) of 420 x 260 x 200 mm (16.5 x 10.2 x 7.9 in), base weight of 9.6 kg (21 lb), and the ability to traverse bumps up to 85 mm (3.4 in) in height. Power comes from a lithium-ion battery pack, as usual. More detailed data should be appearing at www. sanyo.com by the time you read this. Watch for Floating Objects Okay, they’re not the most complex self-operating devices you’ve ever seen, and all they basically do is bob up and down; measure tempera- ture, salinity, and velocity; and relay the information back home. But the amazing thing is that the International Argo Project (www.argo.net), with support from more than 40 countries, has launched more than 3,000 of the things since 2000, and they are scat- tered all over the globe. In the operational cycle, each float spends 10 hours at the surface, descends to its drifting depth of 1,000 m (3,281 ft), and stays there for eight to 10 days, drops to the profiling depth of 2,000 m (6,562 ft), then makes its measurements during a 10 hour ascent. The objective is to allow the world, for the first time, to take the pulse of the oceans on a continuous basis and relay the information to whoever needs it within hours of its collection. And “whoever” includes you. For the beginner’s guide to accessing Argo data, log onto www. argo.ucsd.edu/Frbeginnersguide. html. You’ll be giving speeches on climatology in no time. SV Robytes Diagram of an Argo Active Float. Photo courtesy of the Argo Information Centre. iRobot’s PackBot Explorer and Sanyo’s upcoming underfloor robot. Photos courtesy of iRobot and Sanyo Electric Co. Ltd. SERVO 01.2008 9 Robytes.qxd 11/30/2007 11:19 AM Page 9 10 SERVO 01.2008 Z eno — due on the market as a toy in 2009 — is the closest thing to human that a robot has become. Its facial expressions are a story all to themselves, enabling the most complete robot personality and human-to-robot emotive interactivity to date. Want some proof? Read on! Zeno is a 16-inch, six-pound, interactive robot boy developed by Hanson Robotics with help from a number of vendors including RoboGarage and roboticist Tomotaka Takahashi, of Japan, who is responsible for creating Zeno’s body. The body prototype uses 18 servos, enabling the robot to walk, run, balance on one foot, lie down and get up, and gesture, as in non-verbal communication, according to Dr. David Hanson, PhD, who worked with Takahashi to produce the combined robot, Zeno. Zeno is Born Only recently completed (September 2007), Zeno, the boy robot, offers every human facial response. Zeno (animation software from Massive Software and Maya software) is the world’s first “complete character robot,” according to Dr. Hanson. Complete character means Zeno has facial expressions, walking and ges- turing expressions, and conversational capabilities like a complete human being would have. Zeno smiles, frowns, and gets angry. He looks sad, surprised, and afraid. He can present confusion or concentration as well, according to Dr. Hanson. The mouth moves when Zeno is speaking, the eyelids each work inde- pendent of the other, and the eyeballs turn side-to-side, and look up and down. “In the toy, we intend for the ears to wriggle,” says Dr. Hanson. Zeno can nod, turn, and tilt its head. “These motions can be used expressively, as well as to affect eye contact with people and otherwise look around the robot’s environment,” Dr. Hanson says. Zeno — like other Hanson character robots — interacts with people with a full range of robotically orchestrated facial expressions and conversation enabled by Hanson’s Artificial Intelligence software and carried out by Hanson’s patented robot mechanics and materials. Thanks to a company called Sensory, Zeno recognizes and understands human speech, according to Dr. Hanson. Zeno can respond with substantial verbal exchanges. Not short on words, Zeno’s vocabu- lary is what scientists like Dr. Hanson call “arbitrarily large” in size, meaning it is more than big enough for the job at hand. “As people talk with the robot, the robot listens especially for words and phrases most pertinent to the recent conversation,” says Dr. Hanson. Zeno analyzes human speech to get the intent of the conversation. While the robot makes errors in speech recognition 10-20 percent of the time, it can still respond to human commentary, staying on topic, according to Dr. Hanson. This mirrors human exchanges, in which people generally stay on topic but allow conversation to flow and take Contact the author at geercom@alltel.net by David Geer Zeno — The First Complete Character Robot Human interaction is its main attraction . Photos are courtesy of Thomas Riccio unless otherwise noted. Even from the start, Zeno’s head was more than a hat rack. Here is a shell of Zeno’s head with notes and numbers; a part of the design process. A clay mock-up of Zeno from the design phase. Geerhead.qxd 11/30/2007 11:29 AM Page 10 . control of the servo. Unlike the 0xEB command which locks the servo position, the 0xEF command will allow the servo to be moved by hand. Servo positions. Kerley subscribe@servomagazine.com MARKETING COORDINATOR WEBSTORE Brian Kirkpatrick sales@servomagazine.com WEB CONTENT Michael Kaudze website@servomagazine.com