Minutes of the PARTS meeting on March 1st, 2003

President Pete Skeggs opened the meeting by showing a video of activities that occurred during the ORTOP FIRST LEGO League state tournament at Clackamas High School in January. Several PARTS members volunteered to help conduct that (and previous) competitions.

Pete also read a letter from Dr. James Morris, chairman of the Portland State University Department of Electrical and Computer Engineering. Dr. Morris thanked PARTS for the $250 scholarship, and announced that the recipient of the scholarship for this year is Mikhail Pivtoraiko, a PARTS member who has helped maintain many of the robotics lab activities while Dr. Marek Perkowski is on his sabbatical.

Pete announced that PDXBOT.03 will be held May 25th (Sunday of Memorial Day weekend) at the Smith Center Ballroom on the PSU campus. Use of the room may cost PARTS $780, but we’re hoping that a portion (or all) of the cost may be waived by PSU based on involvement by RAS, the PSU Robotics and Automation Society student chapter of the IEEE.

Pete showed his proposed PDXBOT.03 poster, and encouraged other submissions from PARTS members. Pete also passed the PDXBOT.03 press release around the room and invited suggestions for changes. PDXBOT.03 will feature a legged walker race (a new event this year), line following (beginner and advanced), sumo (micro, mini and Japan classes), robot talent show, tech demos, and vendor displays and sales.

Larry Geib is the PDXBOT.03 event coordinator; he announced that the next PDXBOT.03 planning meeting would be held the next day (March 2nd) at 2:00 pm at "the lab" (the Lucky Labrador Brew Pub, 915 SE Hawthorne.) Larry said that judges are needed for our competition, and asked for volunteers who would like to be trained by Bill Harrison sometime within the next two months.

Larry said that rules for all competitions would be posted on the PARTS website as soon as possible. Larry reported that PARTS member Stu Caruk had cut out a flat steel five-foot diameter ring for the Japan-class sumo competition. Stu had to buy sheet steel (in addition to the original steel which turns out to have been coiled and was not flat) in order to produce a flat surface. Stu’s company, Innovative Economical Solutions, is a de facto sponsor of PDXBOT.03.

Larry showed his tape color test board on which he tested various colors of vinyl tapes to find colors that were detectable by IR sensors. Larry reported that all colors he tested other than black were essentially invisible to IR sensors. Larry said that if he could find a tape color that would be sensed as "gray", he might include a gray shortcut in the line following course.

Larry described the legged walker competition. The course will be made of thin white melamine, three feet by seven feet, with black stripes along the sides, with a black turnaround area and wall at the far end of the course. Larry said the robot must start completely within the starting region at the near end of the course, thus limiting the robot size to less than 1 foot by three feet. Handicapping of robots will be based on Alexander’s Formula to ensure that the robot with the most efficient gait wins. Larry said that the robot body can touch the surface of the course.

The Show and Tell session started with Daryl Sandberg demonstrating his moon rover MR2. MR2 features four-wheel drive and four-wheel proportional steering with independent suspension. Daryl has mounted his X-10 wireless video camera on MR2, and fed the output from the receiver into the video projector. He drove MR2 to the back of the room, up the ramp, out the door, down the hall and into the parking garage before the video signal was lost.

Tim Weaver reported that he has finished the mechanical part of his new mini-sumo robot, and has been using Eagle circuit board layout software to design his board. He proposed a PARTS library of device layouts to make board design go faster. Tim Rohaly said that other sites have Eagle component libraries, and that there are symbol converters to convert from Eagle to other companies’ software products.

"Viscious" showed an in-progress wooden three-lobed infinite loop that he is carving out of wood.

Eric Stewart said that Supercircuits has a fairly high resolution video camera for $109.

Paul Burkey showed a brochure for a two-ounce color Robo-Cam designed for use in model aircraft and model trains. (The brochure didn’t make it completely around the room, so I don’t have the manufacturer name or website information. A Google search turned up numerous suppliers of miniature cameras with rf transmitters.)

Dana Weesner brought a copy of Radio Control Car Action magazine and reported that it is full of neat model car suspension components that might be applied to robots. Dana also reported that the Japan-class sumo competition is scheduled for Tuesday, March 18th in Seattle. THIS JUST IN: THE EVENT HAS BEEN CANCELLED

Robert Pearson asked about video resolution of the cameras typically used for robotics. Daryl responded that the low cost of the X-10 system means that the cameras used are really cheap. Video resolution is usually a function of camera cost.

Mark Medonis showed a silicone rubber mold used to produce a plaster head. The head was sculpted by local sculptor Joseph Highfill, who then produced the silicone rubber mold. Mark suggested that PARTS members interested in sculpture should check out the Pacific Northwest Sculptors website. Mark plans to make face pieces to give Maxwell a more lifelike appearance; he plans to start with a vacuum-formed plastic skin. Mark also showed a copy of Cinefex magazine that details how motion picture special effects are done.

Steve Davee showed his new micro sumo with an internal rechargeable battery pack, and also showed a BEAM micro-sumo robot.

Monty Goodson reported that he has been working with CAD to design his micro-sumo robot and micro controller board. His board will be one inch square and will include an Atmel processor, a voltage regulator, and h-bridge drivers for his motors. Monty uses Pro/Desktop Express (a free download) for CAD designing; a library of common mechanical parts is available at http://www.thomasregister.com/af/cadtitles41/.

Dylan reported that a friend has used a SuperCam in an R/C helicopter, then in a large sailplane. The camera system is really sensitive to vibration (which is why it was removed from the helicopter).

Ben Schaeffer is a programmer who is interested in BEAM robotic technology.

Jonathon Spiva and Rob Belcher (builders of "the robot with no name") brought in their completed Rick Farmer PIC evaluation board onto which they had assembled sensors for their wheel encoders.

Todd Reser made the trip from Walla Walla and brought his latest creation, a robot that follows him around. The robot tracks his position with an IR sensor that seeks an IR source clipped to his belt, and sonar sensors are designed to keep the robot from approaching too closely. Following the meeting Todd’s robot followed him around the parking garage. Todd used Devantech motor speed controllers that he bought from Acroname.

John Hurley showed a radio-controlled scale model of a Freightliner tractor-trailer that he repaired for an uncle. This was a custom-made model, and has some unique features. The truck has only one motor that is connected to several differential drives with universal joints, proportional steering and independent suspension. It has several digitized sounds, such as motor starting, air brake release, and horn.

Two PSU instructors (sorry guys, I didn’t get your names) are teaching a robotics course during Marek Perkowski’s sabbatical. They are using the Mark III mini-sumo kit, and wanted to borrow a mini-sumo ring. Larry Geib said that he’d make sure they had a ring to use if they contacted him following the meeting.

Pete Skeggs showed the schematic for his second-generation micro-sumo controller board. He also described how he used a clear polyurethane adhesive Bumpon as a lens to reduce the field of view and increase the sensitivity of Sharp IR sensors. He described how IR sensor sensitivity can be reduced by driving the sensor at other than the nominal 40 kHz frequency. Pete’s new micro controller board has a Dallas Semiconductor DS 1085 scalable divisor for generating clock frequencies, so "pulling" the frequency of the IR sensors is fairly easy to accomplish.

The next PARTS meeting will be Saturday, April 5th, 2003.