Sunday, May 13, 2012

2.007 = Wide-open spaces for tinyKart and Kramnikopter!

Oh yeah, there's also the whole robot contest thing:

It's like mini-FIRST.
For the past four years, I've been a teaching assistant for 2.007: Design and Manufacturing I, a sophomore-year mechanical engineering design class where students each create a small (16"x16"x12") robot to compete in an annual competition. This class, formerly numbered 2.70, is the origin of the FIRST Robotics high school level competition. If you don't believe me, here's Woodie Flowers with a giant camera octopus:

Just like in FIRST, there's a new challenge every year, and this year's game was Tech County Fair. Robots scored points for collecting arcade tickets, filling a balloon, hitting a high-striker, and spinning a scale Ferris wheel. During the competition, my main job is running the scoring computers. Here's a view from my desk down on field level:

This year, only about 76 robots (out of a class of ~140) entered the final contest, which is optional and doesn't count toward their grade. On one hand, I would like to have seen more of the robots finished. But, having fewer robots in the event means that the ones that do compete tend to be very good and the matches are more exciting. Here's a picture of the winning robot pair:

The bot with hammers on top of it would hit the high-striker (not with the hammers, those were just ballast). The smaller crab-looking bot would pinch the Ferris wheel and spin it, as shown in the picture. Both robots could autonomously find their targets and start their tasks, a huge advantage in the final rounds.

Two other really cool entries that unfortunately did not make it to the final rounds were the Whitelaw Prize (design award) winners:

The bot on the left had several unique features that I've never seen on 2.007 robots before. Instead of striking the lever, it would lift the high-striker mass with a tape measure-like constant force spring that extends from a roll inside the robot chassis. The green Banebots wheels look cool and provide tons of traction. (Are they even kit-legal?) But the real surprise was that the wheels could be steered much the same way as Twitch, having a 0º, 45º, and 90º orientation. The steering was accomplished with crossed-over belts instead of linkages. Also, the whole thing was controlled using DTFM tones from a telephone, just because.

The bot on the right has a more conventional but very well-built 2WD drivetrain. Its showpiece is a custom-made steel flywheel that spins up to a few hundred RPM. It released its stored energy into the high-striker lever so effectively that this robot damaged pretty much all of the practice levers and they all had to be replaced for the contest. It could also spin the Ferris wheel using rubber-coated rollers on the back.

You can watch the two-night competition at the following links:

At the intermission of the Finals (1:55:20 in the second video), you'll get to see the other reason why I enjoy the 2.007 final contest: three days of access to a huge venue with high ceilings. I brought 4pcb and Kramnikopter to the event and while I was testing out the $35 HD Wing Cam I just got for Kramnikopter, the AV crew asked if it could lift their GoPro. It turns out that the Talon frame is pretty much a perfect match for the GoPro, and I got to do some flyover videos of the contest field. Here's some comparison video between the cheap but lower-quality HD Wing Cam and the GoPro:

The HD Wing Cam shoots in 720p and really needs good lighting to work well. But it's small and cheap. The GoPro shoots full 1080p and has much better color balance and image stabilization, but it's $300. It really seems like the way to go for this size quad. They didn't let me keep it, though, so a few days later I went out with my HD Wing Cam and did some more outdoor testing:

You can catch a few glimpses of the giant hexrotor, which flew for a bit too!

Another new 2.007 event this year was an official Electric Vehicle Section final contest. We've had an EV Section (optional, for people who are bored with robots and like EVs) for a few years now, but there hasn't been a separate final event specifically for the vehicles. This year we ran a 50-meter drag race and a unique urban hill climb in a parking garage. (Both time trials, no actual racing for safety reasons.) You can see a full summary of the event on Charles' site. I'll just include the video highlights:

tinyKart, Chibikart, and Pneu Scooter also did some timed runs, since the instructors should be allowed to have some fun also. tinyKart did a 6.52s run on the 50m drag race, about what I would have predicted. It also did a 53.9s run up the garage with a peak power draw of 4.1kW from the batteries. I intend to finally convert tinyKart to running my DirectDrive controllers, so it's possible it will get a performance upgrade soon. (Or there will be a lot of DirectFET smoke.)

Coming soon: FFv1.1, dynamometer, Gen. 1 sensorless write-up.


  1. I'm pretty sure I can do better than a 53.9s or 49s run on tinykart. =P

  2. Needs more grip. 49s was the old layout where the finish was at the end of the 7th ramp. Now, with the finish at the start of the 8th ramp, getting under 50s would be very hard.