Team Robo Monster™

Monday, May 23, 2005

Roboteqs back in action!

Over the last week we made major progress from the site visit - we got our Roboteq motor controllers back online! At the site visit, a corrupted Flash memory in the Roboteqs prevented us from driving - the steering motor couldn't be controlled. The reason was an upgrade gone wrong - when we tried to upgrade the Roboteq software the system crashed and became useless.

Fortunately, the creator of the Roboteq, (Cosma), provided a custom-compiled program which recovered the Roboteqs from the dead and allowed them to be upgraded. We tested them last week and had great positioning of the steering brake motor.

Now, we're going to go back to the site visit area and try to run our GPS waypoint follower program.

Wednesday, May 18, 2005

Our Site Visit...

Well, it's been one week since the site visit for team Robo Monster, so I thought I would post a summary. Overall, there was a lot of great stuff, particularly for a team which started a mere 12 weeks ago. The DARPA reps were particularly interested in the custom-built vehicle, and talked to offroad racing engineer Brian Kirby for about an hour. They were impressed with his techniques for keeping his custom-built vehicle cool in hot environments, and his unique modular method of integrating robotic components with the base system.

The DARPA reps were also impressed with our "sensor-dense" system incorporating multiple IR and ultrasound detectors, developed by our microprocessor experts Michael Wilson and Kerstin Gilg. Working under deadlines, Michael and Kerstin created a custom board managing and processing information from 4 Sharp IR sensors plus one Devantech SRF04 ultrasonic sensor. Currently, these sensors are on the front bumper. We plan to expand the system to handle 8-15 sensors, and array the sensors in a grid on individual body panels of the vehicle, providing a sort of infra-red "touch" sense. We're in good company in this "sensor-dense" concept - NASA recently promoted a new system they are using to make robotic arms sensitive to touch in their environment using similar IR sensors. Check out the NASA project at this link.

Despite the successes, we had some areas which are more challenging. The biggest one was our motor controller, whose Flash memory became corrupted during an upgrade and could not be used to control our steering motor. As a result our site visit was 'static' - we demonstrated vehicle systems in place, and did not attempt to send the vehicle to our RDDF waypoints. The Flash memory became corrupted via a series of unlikely accidents. Two days before the visit, we discovered that our motor controller (Roboteq) would need the upgrade to properly position the steering. When the basic upgrade methods did not work, we called the developer in Switzerland and walked through a special upgrade - an upgrade which, unfortunately corrupted the Flash memory instead.

Fortunately, we've received a special program from the developer which will rescue or motor controller - so we plan on doing a demonstration of waypoint navigation in the next couple of weeks after re-installing the software.

Other projects - Taos, Inc. is sending us a special ambient light sensor for evaluation on our vehicle. We plan to use this special sensor, which has a response range comparable to the human eye (40,000:1) in developing our "sun sensor." This custom sensor will use the Taos chip to determine absolute lighting levels around the vehicles, and also, via a unique "sundial" arrangement, the relative contrast of shadows. Combined with another Taos sensor which measures overall color (we will use it to measure the "blueness" of the sky) we will have shadow contrast and direction information. This information in turn can be used by our vision processing algorithms to predict how deep the shadows should be around an object, as well as their location - improving Robo Monster's vision.

Tuesday, May 10, 2005

Making it happen

May 5
Good news today - our E-stop is fully functional! We've got compressed air that slams the brakes when the power is cut, and manual and electronic relays are installed. Computer integration has been a bit more of a challenge - yet another computer blew up on us onWednesday(!) But we're testing our home brew laser rangefinder on a variety of colors and textures - it will be lots of fun if this $100 instrument does the job. We've also hooked a "fail-safe" ultrasound unit from Sports Imports, Ltd. This system was designed for parking cars, but two of our programmers have now "hotwired" the system so we can connect it directly to our computers. Our robotic senses at the site visit will be primitive but functional. - Pete Markiewicz, Team Leader