Tạp chí Servo
Vol. 5 No. 12SERVOMAGAZINEHERO•SERVOS•SPARE THE ROD, SPOIL THE BOT•TASK PRIMITIVESDecember 2007 Cover.qxd 11/6/2007 3:46 PM Page 84 Order 24 hours a day, 7 days a week www.Jameco.com Or call 800-831-4242 anytime ©Jameco Electronics. *According to the line cards on their web sites on August 28, 2007. Trademarks are the property of their respective owners. OTHER JAMECO ADVANTAGES: More major brands of semis than any other catalog. 99% of catalog products ship the same day. Lowest prices guaranteed, or we pay 10%. Major brand names and generic equivalents for even greater cost savings. 5 10 15 20 We’re passive aggressive When it comes to passive products, we don’t pull any punches: we stock more major brands of passive components than any other major cata- log distributor.* So whatever brands you need— from AMP or AVX to Vishay or Wakefield— you’re more likely to find them all at Jameco. Check our “stats” below and see for yourself. It’s another Jameco advantage. 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CoverInside.qxd 11/1/2007 3:10 PM Page 2 SERVO 12.2007 3 Full Page.qxd 11/1/2007 3:16 PM Page 3 4 SERVO 12.2007 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 07 Bio-Feedback 18 Events Calendar 19 Robotics Showcase 20 New Products 66 Robo-Links 73 SERVO Webstore 82 Advertiser’s Index Columns 08 Robytes by Jeff Eckert Stimulating Robot Tidbits 10 GeerHead by David Geer Tortuga — From Isle of Pirates to Underwater Spy 14 Ask Mr. Roboto by Pete Miles Your Problems Solved Here 60 Lessons From The Lab by James Isom NXT Packbot: Part 2 68 Robotics Resources by Gordon McComb Using Lasers With Your Robots 76 Appetizer by Daniel Albert Transitioning Sequencer Using Static Frames for Biped Control 79 Then and Now by Tom Carroll Servos PAGE 79 TOC Dec07.qxd 11/5/2007 4:08 PM Page 4 12.2007 VOL. 5 NO. 12 SERVO 12.2007 5 ENTER WITH CAUTION! 22 The Combat Zone 31 Votrax SC-01 to SpeakJet Translator by Robert Doerr Break the language barrior with your HERO robot. 36 GPS by Michael Simpson Part 3: Parse positional data from the NEMA protocol. 43 Spare the Rod . Spoil the Bot by Karla Conn Rewards and punishments can serve as fundamental motivations for your robot to learn by. 46 Programming by Demonstrating Robots Task Primitives by Alexander Skoglung and Boyko Lliev Using imitation to teach robots isn’t as straightforward as you’d think, but it can be done. 51 Using FRAM for Non-Volatile Storage by Fred Eady If EEPROM densities are too small for your robotic application and you don’t want to design in a hard drive or battery-backed SRAM, then FRAM is your answer. Features & Projects PAGE 14 TOC Dec07.qxd 11/5/2007 4:08 PM 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 Alexander Skoglund Boyko Lliev Karla Conn Dan Albert James Baker Chad New Paul Ventimiglia James Isom 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 Michele Durant ADMINISTRATIVE ASSISTANT Debbie Stauffacher Copyright 2007 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. True Autonomy When roboticists talk of autonomy, it’s generally understood that this elusive goal will be achieved through advances in computational methods, such as artificial intelligence algorithms, more powerful processors, and increasingly powerful and affordable sensors. However, achieving truly autonomous robots will require more than simple computational evolution. It’s a misnomer to call a robot that can navigate a room without human assistance ‘autonomous’ when the duration of autonomy is limited to perhaps a half hour because of battery life. Other than simplistic stimulus-response BEAM robots (see Figure 1), the Mars rovers are perhaps the best examples of computationally and energetic autonomous robots. However, even the rovers are controlled remotely by scientists at NASA. The advances in battery technology, fuel cells, and power management chips haven’t kept pace with computational advances in energy management, such as behavior modification. Unfortunately, behavior tactics such as resting, altering speed or path to reflect remaining energy stores, and shutting down unnecessary sensors can only go so far in extending the operating time of a robot. New sources of energy must be identified and perfected. Although there is ample commercial pressure to develop higher capacity energy sources and more effective energy management devices, there are also significant incentives from the military. According to the DOD, soldiers of the near future are expected to be assisted by electronic devices ranging from audio, video, and data communications equipment, night vision gear, and wearable computers, to exoskeletons. And these devices will require an unprecedented amount of portable power. In response to this need, the Department of Defense Research and Mind / Iron by Bryan Bergeron, Editor Mind/Iron Continued 6 SERVO 12.2007 FIGURE 1. Solar powered light-seeking BEAM robot. Mind-Feed Dec07.qxd 11/5/2007 4:34 PM Page 6 Engineering Wearable Power Prize is offering $1M for the first place winner for the best wearable electric power system prototype. The competition — which is open to individual US citizens 21 or older — will be held in the fall of 2008. The grand prize goes to the developer of the technically superior power vest that weighs 4 kg or less, operates continuously for four days, and provides 20W average and 200W peak. See www.dod.mil/ddre/ prize/topic.html#7 for details on the competition. Even if you don't take part in the competition, consider the energy autonomy of your next robot design. While you probably don't have access to Sterling isotope thermal generators or other esoteric energy sources available to military robotics designers, there are numerous promising technologies that you are free to explore. One that I've followed for several years is illustrated by the predatory robot EcoBot II, developed by the University of the West of England in Bristol. The EcoBot II uses a microbial fuel cell to generate electricity from flies. Bacteria in the microbial fuel cells metabolize sugars in the flies, releasing electrons in the process. The robot isn't yet up to the capabilities of the Mr. Fusion Home Energy Reactor-equipped De Lorean featured in “Back to the Future” — top speed is 10 centimeters per hour. However, the EcoBot II can travel for five days on just eight flies. If you have an aversion to flies and other decaying organic matter, you can try your hand at extending the basic BEAM robots, available from several vendors featured in SERVO. SV Dear SERVO: In reference to the September ‘07 Robytes . Holy cow! $69 million for an RC airplane? Wow, where can I sign up? I think as a tax payer I should feel screwed! Who am I? I used to fly RC planes before I became a pilot. I’ve built a four seat airplane, and been president of an EAA (experimental aircraft association) chapter. I know a bit about what airplanes are, and what they cost. One of the members of our EAA chapter built a Lancair 4, which would be a 300 mile per hour airplane. He went top shelf on it, and spent about $400,000 on it. Sure, it only has half the payload of the MQ-9 (1,550 lbs), but it seems like for not a lot more, one could build it bigger, and get the payload. Looking at an Epic Dynasty, it has 3,300 lbs payload, and is priced under $2 million; it’s capable of 340 knots. The specs might be misleading with the empty and max takeoff weights but that is with an interior, and equipment for people. Strip all that out and you can have a UAV. Basically, the remote control is some extra wiring to the auto pilot servos. I am to believe that is worth 50 some million dollars? So, maybe someone might say I am comparing “toy” airplanes to some commercial aircraft. How about a Boeing 737? Well, right from Boeing, ready to fly, they list at $49 million. I guess a $20 million conversion would be reasonable (probably not). But this aircraft is capable of hauling over 30,000 lbs (about 10X the MQ-9). It can also cruise at over 500 mph. I am very sad to hear the way things are going in the UAV market. People claim the UAVs are supposed to be cheaper and safer, but it still takes a crew of two to fly this MQ-9, where an F-35A lightning II will only cost about $50 million and takes a crew of one. It’s capable of carrying 18,000 lbs and flying past mach 1 in a stealth mode carrying smart weapons. This manned aircraft is clearly a more useful aircraft. Tom Brusehaver Dallas,TX SERVO 12.2007 7 Resources • EcoBot II — Self-sustaining killer robot creates a stink. New Scientist , September 9, 2004. www.newscientist.com/article.ns?id=dn6366 • EcoBot II in action. www.youtube.com/watch?v=1Nuw654pFbU • BEAM Robots. www.solarbotics.net; www.solarbotics.com; www.geocities.com/SouthBeach/6897/beam2.html • How Fuel Cells Work . How Stuff Works . www.howstuffworks.com/fuel-cell.htm Mind-Feed Dec07.qxd 11/5/2007 4:35 PM Page 7 8 SERVO 12.2007 Fooling Virtual Robots A highly abstract but interesting concept has emerged from the University College London (www.ucl.ac.uk), where Dr. Beau Lotto and other researchers have been experimenting with “virtual robots” to understand why humans can be fooled by visual illusions. Some folks at the UCL Institute of Ophthalmology trained artificial neural networks (essentially, virtual toy robots with tiny virtual brains) to “see” correctly (i.e., as we do). They trained the virtual critters to predict surface reflectance in a variety of 3D scenes such as found in nature. When the bots examined a range of grey scale illusions, they often made the same mistakes that humans do. Among the study’s conclusions is that “it is likely that illusions must be experienced by all visual animals regard- less of their particular neural machin- ery.” For details and some entertaining illusions, visit www.lottolab.org. Concept Car Includes Companion Bot At the latest Tokyo Motor Show, Nissan (www.nissanusa.com) unveiled the Pivo 2 electric concept car, evolved from the original three-seater that first appeared in 2005. It is mechanically as strange as it looks, given that the wheels (each of which is powered by its own motor) can turn up to 90°, and the cabin can rotate 360°, so you can drive it for- ward, sideways, or backward and never need a reverse gear. It’s powered by lithi- um-ion batteries and uses “by-wire” con- trol technologies rather than mechanical systems for braking and steering. But possibly the strangest feature is the “Robotic Agent” that rides with you everywhere you go. It’s basically a bobbling head, located near the steering wheel, that communicates with you in either English or Japanese. Aimed at making “every journey less stressful,” the Agent speaks in a “cute electronic voice” and provides a link to everything from basic vehicle functions to searching for a parking spot. According to Nissan, the head can sense the driver’s mood by analyzing facial expressions (it has digital eyes and a microphone) and deliver prepro- grammed phrases that might include “Relax, don’t worry,” “You’ve dripped Big Mac sauce into your lap,” and “Put away that gun.” At this point, the car is fully functional but — alas — is still too expensive for the commercial market. Fortune Teller in a Bowl Also too expensive for the com- mercial market but there anyway, is the Swami Conversational Robot, avail- able from Neiman Marcus (www.nei manmarcus.com). This goes way beyond the old mechatronic gypsy for- tune teller machines of penny arcade fame, although, peeping out from his glass dome, he does bear some resem- blance to Zoltar. Under the control of a laptop running special AI software, this guy generates facial expressions using some 30 micromotors and can watch you via eye-mounted cameras. Apparently, you can teach him to recognize family members, have meaningful conversations with you, and answer questions intelligently. That’s probably more than the afore- mentioned family members can do, but the catch is that this thing costs more than my first house: $75,000. Give ‘em the Bird for Christmas On a level that will allow it to fit your Christmas budget is Squawkers In this image, it appears that the dark stripes on top are darker than the white stripes on the front of the object. But a mask placed over the image reveals that the “white” stripes in the foreground are exactly the same as the “grey” ones on top. Thanks to Beau Lotto/UCL. Nissan’s Pivo 2 concept car. Photo courtesy of Nissan Motor Company. The Swami Conversational Robot. Photo courtesy of Neiman Marcus. by Jeff Eckert Robytes Robytes.qxd 11/1/2007 11:16 AM Page 8 McCaw, recommended for children over 5 years and very lonely people of all ages. Widely available on the Internet for about $55, it talks, squawks, and is nearly as annoying as a real parrot. He can repeat any words spoken to him, give appropriate responses to prepro- grammed commands, and learn new responses. Put him in dance mode, and he will sashay to whatever music you play or even provide his own music. In terms of mechanics, Squawkers can move his head, flap his wings, eat a cracker, and even give you a smooch when you touch his beak. Probably the best feature is that he goes to sleep when his eyes are covered or the room gets dark. You can see him at www.has bro.com or in your local toy store. Robot Plays the Theremin As most readers will already know, the theremin — invented by Leon Theremin in 1919 — is one of the earliest completely electronic musical instruments and the first to require no physical contact with the “musician.” As far as I can verify, it was played only by human beings until about 2003, when Ranjit Bhatnagar built Lev specifically for that purpose. Lev, the product of a floor lamp, some metallic junk, and a few micro- processors, has been a solo act since then but is now accompanied by a few “thumpbots,” which provide a rhythmic background to the theremin’s notorious- ly unappealing sound. If you’re curious, a video of the band playing a tune that is said to be Gnarls Barkley’s “Crazy” (but sounds more like belly dance music) can be viewed at www.youtube.com/ watch?v=19RJEnNUg1I. Mini Chopper Fights Fires Most unmanned surveillance seems to be performed by fixed-wing aircraft these days, but the West Midlands Fire Service, over in Birmingham, U.K., is trying out a small chopper, which it has dubbed the Incident Support Imaging System (ISIS). The device doesn’t actually put out fires, but it does provide live video from above the incident scene and aids firefighters in planning an emergency response. Such incidents can also include general rescue operations, inspection of water supplies and gas cylinders, and so on. ISIS is actually a modified MD4-200 vertical takeoff and landing (VTOL) micro aerial vehicle (MAV) built by Microdrones GmbH (www.micro drones.com) over in Germany. The composite shell provides lower weight and EMI shielding and houses instruments that can include a GPS, accelerometers, gyroscopes, a magne- tometer, a still or video camera, and pres- sure, temperature, and humidity sensors. The unit weighs only about 2 lbs (900 g) and carries up to nearly 0.5 lbs (200 g). Depending on the payload, the four battery-powered rotors can keep it aloft for up to 20 min. In spite of the $60,000 price tag, Microdrones has sold 250 of them 16 months after their introduction. Biped Bot Responds to PS2 Controller Closer to home, Dallas-based KumoTek (www.kumotek.com) is a builder of custom and standard bots for education, research, entertainment, and some industrial applications. (Kumo, in case you were wondering, is Japanese for “spider.”) The news there is the introduc- tion of the model KT-X, billed as the first low-cost bipedal root platform that can be controlled via a wireless PS2 controller. The 13-in, 2.9-lb robot can walk, run, do somersaults, and stand up from a face-up or face-down position. KT-X has 17 degrees of freedom, is driven by a 60 MHz HV processor, and comes with 75+ preprogrammed motions. As of this writing, the unit is still under develop- ment, but it should be commercially available “within a few months.” SV Robytes Squawkers McCaw, the latest in the Furreal Friends lineup. Photo courtesy of Hasbro. Lev the musical robot now performs with “thumpbot” friends. Shown with a Moog Etherwave instrument. Photo courtesy of www.moonmilk.com A special version of the MD4-200 is being evaluated for fire and rescue operations. Photo courtesy of Microdrones GmbH. SERVO 12.2007 9 The new KT-X. Robytes.qxd 11/1/2007 11:17 AM Page 9 10 SERVO 12.2007 T he competition is sponsored by the Office of Naval Research (ONR), as well as by AUVSI, according to a Robotics@Maryland aca- demic paper, “Tortuga: Autonomous Underwater Vehicle,” authored by several club members and advisors. The competition “tasks” each robot with six challenges: • Maintain a straight course and head- ing through the starting gate. • Locate the flashing “start” buoy. • Ram that buoy “to free it.” • Locate the first “orange pipeline segment.” • Follow the orange pipeline until it meets a second flashing buoy, which it must also ram. • Follow two more pipelines, locate a sonar beacon, and follow it to the “treasure octagon.” Team members based the robot’s design and construction on the best possible completion of these tasks. Tortuga Design and Construction A serviceable aluminum chassis surrounds and supports Tortuga’s mechanics, as well as an 18.5” long by 8” diameter clear acrylic tube, which houses the watertight components. The team members selected the chassis design for ease of access to the robot’s functional parts, electronics, and other “innards” and attachments. The robot uses an inertial navigation system (INS) to establish its location and maintain its heading. The system is comprised of sensors, processors, and software. These enable the vehicle to establish and change location by adjusting its velocity. The INS includes the following hardware and software: 1) Three magnetometers (to measure the Earth’s magnetic field). 2) Three gyroscopes (to measure angu- lar acceleration). 3) Three accelerometers (to measure Contact the author at geercom@alltel.net by David Geer Tortuga — From Isle of Pirates to Underwater Spy The Isle of Tortuga, Haiti — once a haven for pirates — lives on as the namesake for the University of Maryland Robotics Club’s submer sible competition robot. Tortuga — the Club’s entry in the Association for Unmanned Vehicles and Systems International’s (AUVSI’s) annual Autonomous Underwater Vehicle (AUV) competition — first appeared in the yearly event in Autumn 2007. Tortuga was the first robot that the University of Maryland entered into the Association for Unmanned Vehicles and Systems International’s (AUVSI’s) annual Autonomous Underwater Vehicle (AUV) competition, according to Scott Watson, a University of Maryland student and Robotics Club member. This is a close-up, aft (tail, stern) angle view of Tortuga. The AUV is equipped with four Seabotix thrusters (three of four are visible) to control depth, pitch, yaw, and horizontal translation, according to students who crafted the submersible robot. Roll is statically stabilized with a careful distribution of foam, small weights, and putting heavy electronics (such as the batteries) at the bottom of the pressure hull, Watson notes. The AUV uses a MacMini to interface with all its sensors and motor controllers through USB ports. Photos are courtesy of Scott Watson, University of Maryland student and Robotics Club member. Geerhead.qxd 11/4/2007 6:32 PM Page 10