Hello everybody! I'm mike, the student lead of programming and control systems for team 87. This year, we had an alarming amount of issues with our control system, and now it seems to me that is more than just coincidence.
First off, in the chesapeake regional, we would randomly lose communication between the robot and the FMS. And by randomly, I mean we wouldn't do anything like going over a bump, or crashing into another robot or wall, etc. We ended up using a gaming adaptor from spare parts, but that did not alleviate the problem either. We then were able to sort out all the errors in our code(mostly just references that ended up in autonomous and teleoperated that did not exist in begin.vi.) This persisted throughout both competitions.
In addition, sometimes our spike relays(ran off the relay outputs on the digital sidecar) would not work correctly. The air compressor relay was coded to switch between 0 and 1, yet sometimes it would switch to -1. Also, we had a two way solenoid set up with a diode so we could use it on one channel, which worked with -1, and 1, but not 0. We coded this way, yet sometimes instead of going to -1, it would just go to 0. We did make sure that we did not mix up the channels, as it would do this sometimes but not all the time, and when we reset the robot, the problem went away.
Also during that competition, our new digital sidecar went up in smoke. Just out of the blue. there was nothing around to short across the pins(although I believe they have some sort of protection anyway), and no metal shavings inside the unit. What we did find is a popped resistor right in the middle of the pc board. so we replace it, and on we go.
We arrived at the Philadelphia regional two weeks later, and had yet another problem. The robot would drive fine, but then slow to a crawl for 3 seconds or so, then speed back up. We ruled out the motors and transmissions right away. All 4 motors had the same amount of load on them(checked with an amp meter), and there was no binding in the drivetrain. chains were tight, but tight enough to where the chain wouldn't slip, not tight enough to bind. We checked all the connections, and replaced all circuit breakers with brand new ones. We also know it was not binding because our battery voltage would not change at all when the motors slowed down. not even .2 volts of a difference. We stumped even the brightest teams there with this dilemma, and with no NI representative at this competition, we just continued to play with this problem.
During the semi-finals is where the worst happened. We lost all communications during the middle of the match. When we check our system for loose wires, etc. we notice that no LEDs are lit on the cRIO. Uh oh... We confirmed the power adaptor works, which left us with a dead cRIO. We used our timeout to work on getting a second cRIO flashed and coded, and even the opposing alliance graciously used their time out to allow us enough time to finish.
After the competition, we opened up our cRIO to check for metal shavings, burnt traces, etc. and found absolutely nothing. As if the cRIO just came out of the kit of parts. And sure enough we plug it in and it lights right up again.
With all these issues, it is quite difficult to convince anyone that it is just coincidence. Is it possible for a faulty cRIO to cause all this mayhem? Any other ideas? If it is the cRIO, what can we do to rectify the situation? And if it has to be sent in, would it be covered under warranty? We did receive this in the 2009 KOP(Lunacy Year).
Any help would be greatly appreciated
