07> Vol. 6 No. 7 S E R V O MAGAZINEROBOTICS HISTORY • ENCODER MATCHING • BIG MAMA GEAR MOTOR • CES ROUNDUPJuly 2008 Cover.qxd 6/4/2008 7:36 PM Page 1 Let your geek shine. Meet Leah Buechley, developer of LilyPad—a sew-able microcontroller—and fellow geek. Leah used SparkFun products and services while she developed her LilyPad prototype. The tools are out there, from LEDs to conductive thread, tutorials to affordable PCB fabrication, and of course Leah’s LilyPad. Find the resources you need to let your geek shine too. ©2008 SparkFun Electronics, Inc. All rights reserved. »Sharing Ingenuity SPA R KF UN.COM Full Page.qxd 3/5/2008 4:10 PM Page 2 Free Book with Kit Full Page.qxd 6/2/2008 11:33 AM Page 3 Features 28 BUILD REPORT Apollyon 30 MANUFACTURING High-Performance Drill Motor Modification 32 PARTS IS PARTS Mag Motor Upgrades and Repairs Events 33 Results and Upcoming Competitions Robot Profile 31 Billy Bob 06 Mind/Iron 07 Bio-Feedback 22 Events Calendar 24 Robotics Showcase 26 New Products 70 Robo-Links 71 SERVO Webstore 81 Advertiser’s Index Columns 08 Robytes by Jeff Eckert Stimulating Robot Tidbits 12 GeerHead by David Geer Lewis, the Robot Photographer 16 Ask Mr. Roboto by Dennis Clark Your Problems Solved Here 58 Twin Tweaks by Bryce and Evan Woolley There’s a New Humanoid on the Block 64 Robotics Resources by Gordon McComb Stocking Up with Surplus Electronics 67 Different Bits by Heather Dewey-Hagborg Random Bits 74 Appetizer by Kym Graner Dusting Robots 77 Then and Now by Tom Carroll Robotics — A Historical Perspective PAGE 12 4 SERVO 07.2008 THE COMBAT ZONE . Departments TOC Jul08.qxd 6/4/2008 3:41 PM Page 4 07.2008 VOL. 6 NO. 7 SERVO 07.2008 5 34 CES 2008 Robot Roundup by Ted Larson The annual Consumer Electronics Show does not disappoint with its coverage of robotics in the Tech Zone. 39 Encoder Matching by Robert Doerr Scaling and inverting encoder values to fit your particular application. 44 Big Mama Gear Motors by Fred Eady Learn what it takes to design, build, and code a heavy duty DC motor driver module. 50 Loki Crosses the Pond — Part 2 by Alan Marconett This final installment examines the QwikFlash controller board and the software that runs Loki. 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 ADDITION- AL 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 PAGE 44 PAGE 39 PAGE 34 Features & Projects TOC Jul08.qxd 6/4/2008 3:42 PM Page 5 Published Monthly By T & L Publications, Inc. 430 Princeland Court 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 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 Dennis Clark R. Steven Rainwater Fred Eady Kevin Berry Robert Doerr Ted Larson Alan Marconett Kym Graner Bryce Woolley Evan Woolley Heather Dewey-Hagborg Nick Martin Mike Jeffries Bryan Ruddy 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. Small is Big When it comes to robot components, small is big. If you’ve followed the robotics news lately, you know that academic and military R&D communities are busy at work developing robots that mimic – in form and function – small crawling and flying insects. Need to locate survivors in the rubble of a collapsed building? Simply release a swarm of heat-seeking crawling robots that can squeeze through cracks without disrupting the rubble and endangering trapped victims. Need an up-close view of a hostage situation? A swarm of flying microbots with photosensors could provide police with a composite, real-time image of the victims and their captors. Despite ongoing advances in research laboratories, there are numerous challenges that must be overcome before practical autonomous insect swarms can become a reality. There are issues of how to provide communications between each insect-sized robot and their human masters, local computation, sensors, power, and of course, powerful, lightweight, controllable micromotors. And there’s the underlying issue of cost. A recent advance in the area of micromotors has been the commercial availability of linear micromotors from New Scale Technologies (www.newscaletech. com). Their series of Squiggle motors fills the void between the microscopic nanomotors and the miniature servos and electronic/pneumatic linear actuators popular among robotics enthusiasts. I had the opportunity to evaluate New Scale’s mid-sized offering — the Squiggle SQL-1.8-6 linear motor — shown in the photo. As the name suggests, the motor is a mere 1.8 mm in width. The rectangular motor body is 6 mm long, with a 12 mm axial screw running through its center. The 160 milligram SQL 1.8 is capable of handling a 30 g load when driven by a 400 mW, 40V, 171 kHz pulse. The even smaller SQL 1.5 linear motor can work with a 20 g load. As illustrated in the photo, the electrical connection to the Squiggle motor is via a flex printed circuit strip. With a PC-based control application and USB-to-Squiggle interface, I was able to vary the travel rate from micrometers per second to millimeters per second, with an impressive 0.5 micrometer resolution. Although the relatively fragile motor was glued to a polycarbonate mount Mind / Iron by Bryan Bergeron, Editor Mind/Iron Continued 6 SERVO 07.2008 Piezoelectric Squiggle micro motor on polycarbonate mount shown next to a six-pin DIP for size comparison. Mind-Iron Jul08.qxd 6/4/2008 2:22 PM Page 6 for evaluation purposes, I could easily envision a spider-sized eight-legged walker, powered by 16 skeleton-mounted Squiggles. The size of the peripherals that accompanied the motor — a wall wart power supply, a USB driver card, and a three-foot USB cable — not to mention the desktop PC and software — explains why the robotics shops aren’t offering autonomous robots sporting Squiggle-based grippers and actuators. Even a six-pin DIP dwarfs the Squiggle, much less a PIC or BASIC Stamp. However, the control issue should be partially solved by the time you read this. New Scale has a miniature ASIC driver under development that could form the heart of a Squiggle spider robot. Power issue is another matter. The smallest battery packs that I’ve used are thin-film lithium-polymer cells designed for miniature indoor R/C aircraft. The thin, dime-sized cells power a single-motor aircraft for about five minutes. As such, an autonomous eight-legged Squiggle spider would likely have a lifespan measured in seconds with current battery technology. Even so, in some applications, 20-30 seconds of operation could be worth the cost of a swarm of insect-sized microbots. On the topic of microsensors, with the exception of Hall-effect devices, I haven’t seen any commercial sensor offerings that come close to the level of miniaturization required for an insect-sized microbot. I’d like to have an affordable ultrasonic or IR rangefinder comparable in relative size to the Squiggle. However, consider the challenge in creating a suitable IR rangefinder with standard components. A typical IR LED alone is about the size of an insect’s head. And the available ultrasound rangefinders require even more volume. Clearly, when it comes to microsensors for autonomous microbots, it’s time for a new generation of SMT devices. Although autonomous microbots made completely of commodity — read affordable and readily available — components may be a few years away, there are myriad applications of micromotors in other areas of robotics. The most obvious applications range from the manipulation of camera optics and R/C mini helicopter control surfaces, to control of microvalves in implantable drug delivery devices to surgical robots. Although I expect to see the first large-scale applications of micromotors in the consumer electronics industry, the medical applications will likely have the most profound effect on quality of life. Consider that current surgical robotics rely on standard-sized motors connected to scalpels and other instruments through cables. Although these robotic systems enable surgeons to operate with greater efficiency and effectiveness than traditional methods, because of the physical arrangement of cables and instruments, the working area is constrained to only a few inches across. The use of micromotors connected directly to instruments would allow for a much larger work area for tele-surgeons, as well as lighter, mechanically simpler surgical robots. Size and weight can be critical factors if the remote patient happens to be an astronaut on Mars, or a critically injured US soldier in a remote area of the world. SV SERVO 07.2008 7 Dear SERVO: The “analog” servo block diagram, Figure 5, of the Servo Buddy article in May 2008, is missing the velocity feedback path from the motor to the local pulse generator. Without this damping feedback, the servo will oscillate. After the stretched drive pulse has ended, the motor back EMF is used to modify the next local pulse. In servos that use the NE544 IC, this feedback is from pin 9 to pin 1 via a resistor. For the NJM2611 IC, from pin 11 to pin 15. It is interesting to note that years ago what is now called an analog servo was called a digital servo. Back then, an analog servo required an analog VOLTAGE input. — William J. Kuhnle RESPONSE: While I tried to keep the diagram simple, it might have been good to include that. Thanks for pointing it out. — Jim Stewart SchmartBoard Is Looking for Beta Testers New Website will be Social Network for Electronics Enthusiasts S chmartBoard is looking for people to beta-test a soon to be opened web space call Solder By Numbers™. The website, which is due to launch in late summer, will be a social network for electronics enthusiasts. SchmartBoard is looking for all levels of testers from professional engineers to novices who have an interest in electronics. They are looking for people from around the world. According to SchmartBoard’s VP of Sales & Marketing, Neal Greenberg, “SchmartBoard is not yet ready to reveal specific details about the website, except that it is web 2.0 for electronics enthusiasts. Solderbynumbers.com will be a place to design and build your electronic circuits while you create a worldwide network of peers. The site will be much more than a social network. It will be a place to collaborate, create, communicate, and learn.” To sign up to be a beta-tester, go to www.solder bynumbers.com. Mind-Iron Jul08.qxd 6/4/2008 2:23 PM Page 7 8 SERVO 07.2008 The Vulture Seldom Comes Home to Roost On a more celestial level, DARPA is also funding a competition to develop an unmanned aerial vehicle that will shatter endurance records. The bird will draw 5 kW of power, carry a 1,000 lb (450 kg) payload, stay aloft for at least five years, and remain in its assigned airspace 99 percent of the time while fighting winds encountered at operating altitudes, reportedly ranging from 60,000 to 90,000 ft (18,000 to 27,000 m). The goal is to provide long-term intelligence, surveillance, reconnaissance, and communication missions over locations of interest. Contractors for phase one are Aurora Flight Sciences (www.aurora. aero), Boeing (www.boeing.com), and Lockheed Martin (www.lock heedmartin.com). A variety of propulsion approaches — including solar and internal combustion — will be considered; however, nuclear and lighter-than-air designs have been ruled out. The winning design must comply with space — not aviation — industry standards, because only a “pseudo-satellite” will handle the demanding requirements. A supervi- sory engineer at NASA observed, “What you don’t want to build is a fragile, expensive pain in the butt.” The Aurora offering will be based on its “Odysseus” design, which uses solar power during daylight hours and stored energy at night. It combines three “constituent aircraft” in a 500 ft (150 m), intriguing Z-wing configuration. Boeing is expected to field a design based on the existing British-built Zephyr high-altitude, long-endurance UAV, from partner QinetiQ (www.qinetiq.com). Lockheed Martin is still mum on the subject. The competitors have 12 months to come up with their initial designs for DARPA review. Phase two will end with a three-month flight test of a subscale demonstrator, and the final phase will require a 12-month test of a full-scale vehicle. Mini Network Bots Also pulling down government funding — in this case, up to $3 million over three years from the Defense Advanced Research Projects Agency (www.darpa.gov) — is iRobot (www.irobot.com). Under the grant, the company will develop the LANdroid robot, a portable com- munications relay device. According to the contractor, “This robot will be small enough that a single dismounted warfighter can carry multiple robots, inexpensive to the point of being disposable, robust enough to allow the warfighter to drop and throw them into position, and smart enough to autonomously detect and avoid obstacles while navigating in the urban environment.” The objective is to enable networking in urban areas where buildings and other pesky objects can block wireless operations. In operation, each of the little guys will wander around until it finds a good spot to function as a node and then join the rest of the swarm to form the network. If one is destroyed, the others will adjust their positions to keep the system up and running. New Touch Technology One of the perennial problems in robotics is improving the machine’s Aurora’s Odysseus design: A possible configuration of the Vulture UAV. Photo courtesy of Aurora Flight Sciences. Sneak peak at what the LANdroid robot will look like. Photo courtesy of DARPA. by Jeff Eckert Robytes Robytes.qxd 5/29/2008 2:20 PM Page 8 sense of touch, and what could be a better way to solve it than to learn from our touchy-feely friend, the rat? Enter BIOTACT (BIOmimetic Technology for vibrissal ACtive Touch, www. biotact.org), a project funded by the European Union and involving nine research groups in seven countries. The goal is to emulate how such mammals as rats and Etruscan shrews can rapidly sweep their whiskers back and forth to gather information about their surroundings. Thus, a bot fitted with hundreds of whisker-like sensors may be able to seek, identify, and track fast-moving target objects, even in poorly lit places where machine vision doesn’t get you anywhere. The challenge is to develop new biomimetic computational methods and technologies that enable the technology. But the consortium has been granted four years and $11.6 million to do it, so the odds look good. Showcase of Robotenders It’s beginning to look like the Germanic tribes have a curious fetish about linking robotics with such ostensibly unrelated fields as sociology, philosophy, and art (see last month’s Robytes). In this vein, the upcoming 10th anniversary of the RoboExotica conference recently came to light. According to the event’s Vienna-based creator (www.robo exotica.com), “Until recently, no attempts had been made to publicly discuss the role of cocktail robotics as an index for the integration of technological innovations into the human Lebenswelt [environment], or to document the increasing occurrence of radical hedonism in man-machine communication.” Imagine that. But you can stop worrying, because “RoboExotica is an attempt to fill this vacuum.” RoboExotica generally consists of a series of events (exhibition, conference, workshops, music, and film presentations) held at various locations in Vienna. But this year, sometime after the December 4th kickoff in Austria, it will be presented in San Francisco, as well, “thus facilitating the already existing exchange of ideas between the West Coast’s very much alive technology/ art scene and the RoboExotica mother ship in Vienna.” Unfortunately, the US incarnation will not include the annual cocktail robot awards, where you can enter a machine in one of five categories: serving cocktails, mixing cocktails, bartending conversation, smoking culture, and other achievements in the sector of cocktail culture. To participate, you’ll have to show up at the Rote Bar/Volkstheater Wien (www.volkstheater.at/rotebar .html). The program is still under development, so check the website from time to time for details. Bot Assists Endoscopy This month’s device for taunting the squeamish is EndoAssist, a robotic endoscope manipulator offered by Prosurgics Ltd. Used in invasive thoracic and abdominal surgery, it is particularly useful for ardiothoracic, urological, bariatric, ob/gyn, and general surgery. Perhaps the most interesting feature is that the surgeon controls camera angles simply by moving his head. Glance left, and the camera moves left, and so on. You Robytes Artist’s concept of the “ScratchBot” employing the BIOTACT sensor. Photo courtesy of the BIOTACT project. The EndoAssist robotic manipulator. Photo courtesy of Prosurgics. A contestant from RoboExotica 2007. Photo courtesy of Roboexotica.com. SERVO 07.2008 9 Robytes.qxd 5/29/2008 2:23 PM Page 9 can also pan, zoom, or modify the view in any direction. For a video demonstration that may affect your ability to keep lunch down, visit www.prosurgics.com/prosurgics_ endoassist.htm. Uribot Tends Kobe Airport Finally, the strangest application of robotics of late would be Dasubee, a bot designed specifically to clean urinals. One is already operating in the Kobe, Japan airport. An astute observer will note that it resembles an elephant. Designer Susumu Kanai revealed that this design was inspired by the pachyderm’s trunk, which resembles the powerful water cannon employed by the bot. The ears are handles, the eyes are the start and stop buttons, and its little yellow hat is the filler cap for the 13 gal (50 l) tank. Reportedly, using specially developed antibacterial detergent, Dasubee can shine up a fouled privy in only 10 seconds. If you’re still reluctant to buy one, consider that Kanai has included “a vacuum function to breathe in a scraper and the water of the floor to be able to wash the dirt scattered to the floor together on the function side.” (Something may have been lost in the translation.) You can pick one up for only one million yen (about $9,500). SV Robytes 10 SERVO 07.2008 Dasubee, the urinal bot and its proud operator. Photo courtesy of Impress Watch Corp. P erform proportional speed, direction, and steering with only two Radio/Control channels for vehicles using two separate brush-type electric motors mounted right and left with our mixing RDFR dual speed control. Used in many successful competitive robots. Single joystick operation: up goes straight ahead, down is reverse. Pure right or left twirls vehicle as motors turn opposite directions. In between stick positions completely proportional. Plugs in like a servo to your Futaba, JR, Hitec, or similar radio. Compatible with gyro steering stabilization. Various volt and amp sizes available. The RDFR47E 55V 75A per motor unit pictured above. www.vantec.com STEER WINNING ROBOTS WITHOUT SERVOS! Order at (888) 929-5055 Robytes.qxd 5/29/2008 2:24 PM Page 10