Race day (or so close, yet so far)

Jim and Richard had left when I woke up at 7am so Maribeth (Richard’s wife) and I drove to the speedway where the opening ceremony was about to begin.

All the robots were lined up and the press was there mingling among the teams and everyone was inspecting everyone else’s robot. There was a surprising amount of designs, from full custom vehicles, to converted SUVs, and some converted ATVs. Very few of them had what our team considers a feature, complete driveability.

The opening ceremony was your standard boring affair, with a flag presentation, a singing of the national anthem, a speech from the head of DARPA, and the introduction of the team leaders.

After that we went back to the garage, pondered schedules, and headed out for a test run around the parking lot.

Right before we headed out, though, we hooked up the e-stop “pause” signal so that the car could come to a stop but then could continue on its way when unpaused. We hooked it up to an input on our microcontroller but it turns out the line we hooked it to was a signal to the build in loader code to not run our firmware. It took us almost 2 hours of backtracking and comparing with a known good board before we figured that out though. When it was done I was very stressed.

So then we finally got to do some practice driving. Jim had inverted a term that we suspected was wrong last night and when we tested it, it started working correctly! So we started actually letting the car steer itself around the parking lot while we tweaked controller constants and tried to get it not to over or under correct too much. After about an hour or so we got the go ahead to go over to the practice run and try our code out.

To get around to the practice run we exited through the pit area got to drive on the actual racetrack till we got to the other side! It was very cool. Mike took some pictures. I hope some came out ok!

When we got to the practice area we found out that it wasn’t for maybe practicing fully autonomous mode, it was exclusively for practicing fully autonomous mode. As in we weren’t allowed to drive along in the car! This was bad because until then our controllers had always had a running start. We couldn’t just go from stopped state to 10 mph. We could go from 10 to 20, or from 20 to 10, or hold 10 indefinitely, but not starting from zero. Not onl that but the pause functionality had to work before we could go and we had only just hooked up the signal that morning! It turns out Jim (with me looking over his shoulder and helping and also trying not to let Josh inerrupt him too much) got all the code written in about 45 minutes. And then we were ready.

So I set up the computer like I normally do, but this time engaging everything, which we have never done. I make sure we get paused and that the brake is completely engaged. Then Jim puts the car into park… To me this feels like we just wound up some Giant catapult and disengaged the safety. At any moment the car may spring to life and go nuts. Or just calmly navigate through the waypoints (which we were hoping was the outcome).

So we go back behind the barrier (the whole field is surrounded by huge concrete barriers to help protect against giant runaway robots) and we signal the guy in charge to unpause the car…

… And nothing happens.


So we trudge back on the field and try to figur out what has gone wrong. It turns out the servo that drives the engine throttle has burnt out (something strange happened that morning and had left the servo going full bore against an object that it couldn’t budge). We decide the test run is over and leave back around the track again (which is still very cool!) and head back to the trailer.

At this point Jim and Richard go off looking for hobby shops to buy a replacement servo while Josh and I smuggle my parents into the pits using his tinted windows and leveraging the “only look in the front seat” mentality of the security guards (parents in the back, us up front waving wristbanded arms.

Eventually I take a 1 hour nap while Jim and Richard return with a new servo. We miss our first qualifying run (it was supposed to be at 4:30pm that day) but we get it rescheduled for Tuesday at 9:30am. The servo gets installed, Olive Garden gets our patronage, and Richard, Jim and I go back to the hotel and crash.

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Last Modified on: Dec 31, 2014 18:59pm