Tạp chí Servo
Get an HB-25 Two-pack (#29150) for only $79.95 and save $20! The Parallax HB-25 Motor Controller (#29144; $49.95) provides a simple and dependable motor control system for your motorized projects. With an efficiently integrated heat dissipation design, the HB-25 easily manages 12V motors drawing 25A of current! These are sizable motors, as shown in our two example robots which are both controlled by HB-25s. Motor Size: 0.5 HP Max - No Minimum Motor Supply: 6.0 vdc min - 16.0 vdc max Load Current: 25 A Continuous 35 A Surge (13.8 V) Standby Current: 50 mA @6 V 80 mA @13.8 V (fan on) PWM Frequency: 9.2 kHz Pulse Input: 1.0ms Full Reverse, 1.5ms Neutral (off), 2.0ms Full Forward # of Motors: 1 (or 2 in same direction) Protection Circuits: Over Voltage, Over Current, Over Temp. Indicators: Power (green), Fault (red) Cooling: Forced Air - Ball Bearing Fan Terminals: Screw Post with 35 A Rating Weight: 2.5 oz (71 grams) Size: 1.6” x 1.6” x 1.9” Mounting: (2) 6-32 screws on .800” centers Included: (1) 25 A Fuse Vol. 5 No. 3SERVOMAGAZINEiRobot CREATE•OPENCVPART 3•ROBOTIS AX-12•VEX IN EVERY SCHOOLMarch 2007 04 74470 58285 03> U.S. $5.50 CANADA $7.00 Cover.qxd 2/8/2007 9:44 PM Page 84 P e r f e c t p r o j e c t s f o r k i d s o f a l l a g e s ! P e r f e c t p r o j e c t s f o r k i d s o f a l l a g e s ! WWW.ROBOTSTORE.COM/SRD I-800-374-5764 WWW.ROBOTSTORE.COM/SRD I-800-374-5764 Enthusiasts, Start Dream ing . Gift Givers, Take Note . Engineers, We’ve Got It All! Enthusiasts, Start Dream ing . Gift Givers, Take Note . Engineers, We’ve Got It All! Robotic Kits and Components . The W orld’s M ost Complete Offering! CATALOG I62 I-800-374-5764 WWW.ROBOTSTORE.COM Call for your free catalog today! robotic kits chassis servos passives optos integrated circuits semiconductors muscle wires connectors motors test equipment software books Robotic Kits Components . Robotic Kits Components . .there’s something for everyone! Robotic kits help you and your child to experience and learn about perception and control using a variety of sensors and actuators. Challenge yourself with Jameco’s selection of fun and interactive kits! You or your child can assemble the kits and then enjoy endless hours of discovery. Check out our unique selection of robotic kits at www.RobotStore.com! . Robot Insects & Animals . Programmable Robots . Solar Robots . Educational Kits . Listening, Touching & Seeing Robots . Legged and Wheeled Platforms . Hackable Robots . OctoBot Survivor Kit At Jameco’s RobotStore you can get the world’s most complete robotic offering— all in one place! You’ll find kits for all ages and experience levels, along with gear boxes, servos and chassis, for those who are ready to take on the extreme. CoverInside.qxd 2/12/2007 9:36 AM Page 2 SERVO 03.2007 3 Full Page.qxd 2/6/2007 2:59 PM Page 3 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 4 SERVO 03.2007 36 Seeing With OpenCV by Robin Hewitt Part 3: Follow That Face! 41 Smart Servo: Understanding the AX-12 by Michael Simpson Overview of the Robotis’ AX-12 actuator and beginning the build of “AXbot.” 47 The Vex Challenge Coming to a School Near You by Bryce and Evan Woolley The statewide institutionalization of a FIRST education program into schools begins in Rhode Island. 50 Low Power Robot Communications — Part 2 by Peter Best Details of the PIC18LF4620 firmware. 55 Robot Simulation: Physics by Bryan Bergeron This month’s focus is on the tools and techniques available for modeling and simulating the physics of robots. 62 Beginner’s Robotics on $50 a Month by Eddy Wright and John Jellman Part 4: Servos, Sonar, and a Second Microcontroller: Seeing With Sound. 68 CES 2007 in Review by Ted Larson Coverage of the robotics zone at the recent Consumer Electronics Show held in Las Vegas, NV. 72 ROBOGames Prep by David Calkins This month: Balancing Bots. Features & Projects Page 68 TOC Mar07.qxd 2/8/2007 4:30 PM Page 4 Columns Departments 03.2007 VOL. 5 NO. 3 06 Mind/Iron 07 Bio-Feedback 24 New Products 35 Events Calendar 71 Robotics Showcase 80 SERVO Bookstore 88 Robo-Links 90 Advertiser’s Index 08 Robytes by Jeff Eckert Stimulating Robot Tidbits 10 Twin Tweaks by Bryce and Evan Woolley Hangin’ Around With Team 3310 16 GeerHead by David Geer Explorer I and Explorer Generation II 20 Ask Mr. Roboto by Pete Miles Your Problems Solved Here 75 Robotics Resources by Gordon McComb Bushings, Bearings, and Other Robotic Baubles 82 Robotic Trends by Dan Kara Demography is Destiny 85 Appetizer by Helen Greiner Robots 2.0 86 Then and Now by Tom Carroll Robotics Organizations SERVO 03.2007 5 ENTER WITH CAUTION! 26 The Combat Zone Page 10 TOC Mar07.qxd 2/8/2007 10:23 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 CONTRIBUTING EDITORS Jeff Eckert Tom Carroll Gordon McComb David Geer Pete Miles R. Steven Rainwater Ted Larson Bryan Bergeron David Calkins Kevin Berry Bryce Woolley Robin Hewitt Peter Best Evan Woolley Eddy Wright John Jellman Michael Simpson Helen Greiner John Koepke Russ Barrow Chad New Christopher Gilleski Tim Wolter Robert Wilburn Dan Kara Paul Reese CIRCULATION DIRECTOR Tracy Kerley subscribe@servomagazine.com WEB CONTENT/STORE Michael Kaudze sales@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. Acting as a chaperone for my oldest son during one of his field trips in eighth grade, I had come upon the LEGO Mindstorm System. The Chicago Museum of Science and Industry was hosting a seminar on robotics using this, then new, LEGO Mindstorm System. I was immediately captivated with the genius of this robotic system. A couple of years later, I made a career change to teaching at Joliet Junior College where I immediately employed the LEGO Mindstorm System to teach digital electronics and hold summer seminars for junior high and high school students. I began to reflect back on some of the competitions I had participated in years earlier regarding robotics and thought these robotic kits would provide a great platform for such a competition. My initial desire was to ensure high schools participating in the competition would not have to purchase these LEGO kits or software in order to participate in the event. Nor did I want teams to have an advantage over others through differences in sponsorship or school funding levels. Teams would arrive with nothing more than something to write with and a calculator. I have been fortunate that Joliet Junior College has supported these goals, as well. Now in our seventh year, The Robotic Engineering Challenge is still free of an entry fee. The main goal of the Robotic Engineering Challenge (REC) series is to expose students to the engineering and technical fields. REC provides students with real time, hands-on experience acting in the role of an engineer or technician. The LEGO ROBOLAB™ system provided the framework to bring the engineering experience to each student. Each LEGO ROBOLAB system contains a microprocessor-based smart brick that uses sensor information to complete assigned tasks. The competing student teams must find the right balance between hardware and software interfacing. We can view the software as 'how we want the robot to react' to its changing environment; how it is to think. The software is basically the 'brains' of the robot. The hardware makes up the framework for executing the demands of the program. Much like how our body reacts to our thoughts. The robots that the students build to meet the most challenges are autonomous, that is, the robots think for themselves; no human in the control loop once the run button is pressed. There are two levels of competition: Expert and Novice. The Novice group receives their challenges in sequence. Their faculty sponsor may assist them. The Expert group performs without the help of their faculty advisor. They receive all challenge tasking at once and need to decide which challenge to tackle first. Both groups are under time constraints to complete as many challenges as possible during the competition period. The expert and novice challenges are shown below. Each challenge also requires the students to answer a set of math, physics, or science questions related to a particular challenge. EXPERT: 1) Square Route: Follow a square path. 2) Land Navigation: Move across a bridge and return back to the start position. 3) Search-and-Rescue Robot: Deliver a medical supply payload across a vertical barrier. 4) Bomb Disposal Robot: Pick and place a simulated bomb into a bomb dumpster. 5) Hazmat Robot: Clear a building of a simulated hazardous waste container. Mind / Iron by John Koepke Mind/Iron Continued 6 SERVO 03.2007 Mind-FeedMar07.qxd 2/8/2007 9:54 PM Page 6 NOVICE: 1). Binary 500: Complete one lap around a small track. 2). Move through a small maze. 3). Sumo-Bot: Survive against the house robot. 4) Pool Table: The student robot acts as a cue ball clearing the pool table of balls. 5) H ouse Navigation: Seek and find point-valued cones placed throughout a scaled-down house layout. During the Jan. 2007 competition, we had 31 high school teams (over 130 students) participate. Hopefully, competitions like the REC will interest students in engineering. I feel students are not going into the engineering field because many may feel "over- challenged" by the math requirement. Mathematics is the language of technology and seeing a practical application of the subject makes it more understandable. Most likely, however, students are not exposed to the engineering or technical subject areas until later in the educational process, if at all. It is hard to make a career choice regarding an area that you may know very little about. It is easier to select a career by relying on your daily experiences and impressions of certain jobs. For instance, most people have some impression of the field of nursing because of their interaction with a nurse when visiting the doctor or hospital. Typically, we don't have daily exposure to engineers (directly that is). However, everything around us is a product of the design work of an engineer. I hope in some way that students will gain some insight into the field of engineering from this competition and spark an interest to study this subject area. I was told this competition is a form of 'engaged learning' — I want students to get excited about engineering, math, and science. When I watch the students competing, I would agreed that they are totally engaged in learning and problem solving. SV Dear SERVO: In the January 2007 OpenCV article, there may be an error in the source code listing in Figure 3, page 64. I haven't built the OpenCV library yet, so I am not positive, but line 14 may not be correct. As presented in the article, the cvLoadImage() function is called without assigning the pointer to the returned value. The following test will always be true in this case and the program will always return an error message. It should probably read: pInpImg = cvLoadImage("my_image.jpg", CV_LOAD_IMAGE_UNCHANGED); Other than that minor problem, the article is very informative. I'd run across OpenCV before, but had been intimidated by the scope of it. The article has convinced me to download it and give it a shot. I'm looking forward to the next installment. Robert Wood You're right! Thank you for pointing that out. It's great to hear that the January article motivated you to try out OpenCV. — Robin Hewitt SERVO 03.2007 7 Mind-FeedMar07.qxd 2/8/2007 9:54 PM Page 7 8 SERVO 03.2007 ROV Explores Antarctic Floor By the time you read this, the Isis explorer — operated by the UK’s Deep Submergence ROV Facility — will have completed one of four scheduled plunges to the Antarctic sea bed in an effort to gather information about the effects of glaciers on the ocean floor and to prod whatever animals live there. While there’s nothing revolutionary about ROVs, this is reportedly the first time one has been sent into this environment, and it carries an impressive slew of lights, cameras, sonars, and robotic arms for collecting samples and implanting instruments. Based on the Jason ROV designed at our own Woods Hole Oceanographic Institution (www. whoi.edu), the Isis dangles from the mother ship by 10 km (Wow! - ed.) of cable so scientists can control and communicate with the vehicle in real time. It can travel under its own power, being fitted with six 3.7 kW thrusters, but its 1.5 knot velocity is not exactly breathtaking. On the other hand, any movement at all is pretty good for something that weighs 3,250 kg (7,165 lb) and has the aerodynam- ic qualities of a punch press. For updated information, drop in at www.noc.soton.ac.uk/OED/ROV. Bug Joins NATO Even though it doesn’t look like much, the CyberBug™ from Cyber Defense Systems (www.cduav. com) is a pretty useful little UAV that is designed for military, law enforce- ment, and commercial applications. (It would be fun to have one for personal pleasures such as buzzing the neighbors’ backyard barbecues, but the $10,000 base price makes that a little impractical.) According to the company, the birds can be assembled in just a few minutes and launched right away to provide aerial surveillance. They can fly for up to an hour while sending video and other data to the ground sta- tion, and common tasks include monitoring hazardous events, search and rescue, traffic monitoring, bor- der patrol, and so on. Late last year, three of them were employed to support navigation war- fare scenarios during Trial “Spartan Hammer,” a 12 nation NATO collabo- rative effort conducted in western Greece. A variety of sensor payload configurations were used to collect information used to support signals intelligence and electronic warfare campaigns. Reportedly, a total of 22 sorties were flown with a 100% mis- sion completion rate. Three sizes are available: the micro (2.5 lb), medium (8.5 lb), and large (14.5 lb). A 42 lb version is under development that will fly with a 12 lb payload for up to two hours, or up to eight hours without the baggage. A Real Mean Machine In case you haven’t noticed, Asimov’s Laws of Robotics have become pretty antiquated, and no more so than in the case of the TALON® robot from Foster-Miller (www.foster-miller.com). The com- pany builds mobile platforms for mili- tary, HAZMAT, and SWAT applications, and this model can be configured for different sizes and functions, including stealthy reconnaissance, intruder The Isis ROV, hanging from its launch and recovery system. Photo courtesy of UK Deep Submergence ROV Facility. The CyberBug UAV recently participated in NATO and other military exercises. Photo courtesy of Cyber Defense Systems, Inc. The TALON robot comes in various lethal versions. Photo courtesy of Foster-Miller, Inc. by Jeff Eckert Robytes A re you an avid Internet surfer who came across something cool that we all need to see? Are you on an interesting R&D group and want to share what you’re developing? Then send me an email! To submit related press releases and news items, please visit www.jkeckert.com — Jeff Eckert Robytes.qxd 2/8/2007 9:57 AM Page 8 attack, underwater surveillance, and remote sensing/monitoring.The basic unit is designed to be compatible with a range of hardware, weapons, and sensor systems. More than 80 different payloads have been developed or adapted and mounted on it, including smoke and grenade dropping modules, anti-tank launch- ers, a 40 mm grenade launcher, and a 12 gauge shotgun. You can also get mounts for remotely-controlled weapons including the M240 and M249 machine guns, the M16 rifle, and the M82A1 .50 cal. anti-tank/anti-material rifle. A smaller version is available for stealthy reconnaissance operations, and there is even an underwater model. At present, this is the only mobile platform certified by the Department of Defense for remotely-controlled live firing of lethal weapons, so you proba- bly won’t encounter anything meaner. This One Will Touch Your Heart Possibly more disturbing to contemplate than the TALON — for entirely different reasons — is the Sensei™ Robotic Catheter System from Hansen Medical, Inc. (www.hansenmedical.com). The company recently completed a 20-patient trial as part of 510(k) premarket submission to the US Food & Drug Administration. The trial was an observational study that used the Sensei system to guide catheters into the heart for mapping heart anatomy. The system is designed to provide accurate and stable control of catheter movement in 3D during cardiac elec- trophysiology procedures. Currently, these procedures are performed using a manual technique that requires physicians to perform complex manip- ulations at one end of the catheter with inadequate assurance that the inserted tip of the catheter will respond as desired. The Sensei system consists of three components: the physician workstation, the “instinctive motion controller,” and the robotic catheter manipulator (see photo). The gear may look a bit scary, but Hansen says it will “enhance the ease of use and stability of catheter-based procedures by offering physicians better control over catheter placement, as well as potentially decrease procedure times and radiation exposure.” Solenoid Features Quiet Operation Returning now to an item that readers might actually find to be of practical use, Saia-Burgess, Inc. (www. saia-burgess. com), has introduced the MagShift® line of solenoids to provide actuation in a variety of applications. It is designed to eliminate impact among its moving parts, which results in a noise measurement below 40 dBA, including the end-of-travel stop. There is no impact force at the end-of-travel position, so vibration and noise are minimized. As a result of the elimina- tion of internal components, the MagShift design eliminates residual magnetism and can be configured for either push or pull operation. SV Robytes The Sensei Robotic Catheter Manipulator. Photo courtesy of Hansen Medical. SERVO 03.2007 9 The MagShift solenoids provide power-on noise levels <40 dBA. Photo courtesy of Saia-Burgess. Robytes.qxd 2/8/2007 9:58 AM Page 9 10 SERVO 03.2007 T he FIRST (For Inspiration and Recognition of Science and Technology) organization founded by Dean Kamen offers robotics competi- tions for budding roboticists of all ages and skill levels. Elementary school stu- dents can take their first steps into the arenas of science and technology with the Junior FIRST LEGO League. Middle school students can make forays into the exciting world of robotics with the FLL, the FIRST LEGO League. High school students are faced with the challenge of the FIRST Robotics Competition (FRC). But jumping into the FRC is a huge step. Students go from robots they can hold in their hands to robots that are as big as they are. This can be quite an intimi- dating step up, especially because many teams do not even have the benefit of the FLL as a stepping stone. That’s where the Vex Challenge comes in. The Vex Challenge The Vex Robotics Design System made its debut a few short years ago, and late 2006 witnessed the first official full-scale Vex Challenge competition. A pilot tournament of the Vex Challenge was held at the 2006 FRC Championships, but the 2006-2007 sea- son witnessed an expansion into a com- plete competition with regional events and a championship. Regional events across the nation are being held from December 2007 until spring 2007, and the championship is to coincide with the FRC National Championship in April 2007. The Vex Challenge is a robotics com- petition that aims to inspire and prepare teams for the big robots of the FRC. The Vex robots, arguably closer to “real” robots than the LEGO Mindstorms kit used in the FLL, are intended as stepping stones for FLL alumni or absolute rookies that feel they need a little more experi- ence before tackling the huge commit- ments and challenges of a FIRST team. The Vex Challenge is similar to the FRC in that the game emphasizes cooper- ation and task completion. Vex Challenge teams also get a kit of parts to work with — as you might have guessed, the Vex kit itself. Teams can buy more than one kit, but they are limited to a certain number of motors and controllers, and they can only add non-Vex parts to their robot if they are exact substi- tutes of the part in question (like if you needed more collars but didn’t want to buy another whole kit to get them). There is no weight restriction for the robots, but the stringent dimensional limit of having to fit into a cube 18 inches to a side ensured a challenge. One of the most apparent diver- gences that the Vex Challenge has THIS MONTH: Hangin’ Around With Team 3310 T HE C OMPETITION . FVC IN A CTION . Photo courtesy of Trey Amador. Photo courtesy of Trey Amador. TwinTweaks.qxd 2/8/2007 4:40 PM Page 10