What to do with autonomous

[MichalSkiba]

I've been living in a hole (my bedroom studing for exams) for the past week or so. First off, a question about the uber-accurate Wildstang Positioning System (WSP perhaps?):

1. How were you able to account for wheel slipping? This would occur when your robot would be pushed (while wheels were locked) or sliding down the ramp (for example). I'd immagine that such 'small' inaccuracies could addup to more then +/- 1-inch by the end of the match.

Back to our autonomous mode. I'm thinking (I'm the only programmer on our team) of using a IR seeking/dead reckoning hybrid. If at any point the beacon is blocked, dead (sorry, read 'ded.') reckoning would kickin. It would be adaptive, so the robot would continue in that direction until the beacon can be seen again. The dead/ded. reckoning system would rely on a counter to determine how much longer to go forward, not to overshoot the target.

I'm thinking of having a collision avoidance system; a set of sensors (sonar?) that would try to avoid obsticals (such as robots) by driving around them. It would also try to avoid the platform and the guard rail.

On a sidenote, herding balls will be interesting. I'd imagine that they'd go all over the place unless your robot has a neat device that would keep them under control

Nevertheless, I'd like to hear more on other team's autonomous ideas.

[Dave Scheck]

Originally Posted by MichalSkiba

First off, a question about the uber-accurate Wildstang Positioning System (WSP perhaps?):

It was WPS originally, but we ended up dubbing it StangPS

How were you able to account for wheel slipping?

Very good question. Our system had no slippage detection/correction. (read on...)

This would occur when your robot would be pushed (while wheels were locked) or sliding down the ramp (for example).

It was more of a problem on the ice (HDPE) and performing turns on the ramp.

Like Mike said in a previous post, we didn't need a whole lot of precision. If we wanted to ram a stack (whether freestanding or the group on the ramp), we just had to make sure that the stack ended up in front of our robot.

Our wheel slippage (in normal situations) was
* minimal on the carpet in normal situations
* slight climbing the ramp
* measurable on the ice (HDPE)
* negligable descending the ramp

Therefore, we didn't design programs that spent significant time on the ice. Our double-hit program (hit the left side of the stack, come back, hit the right side of the stack) consistently cleared a good portion of the bins, but was slightly inconsistent due to the slippage on the ramp.

In situations where we came head-to-head with another robot, there was a good chance that we deflected during the collision and recorrected our heading to squeeze past and continue on. If is was the type of collision that stopped us dead in our tracks, that was a different story. Luckilly, those types happened on the ice which allowed our wheels to slip and not burn motors.

I'd immagine that such 'small' inaccuracies could addup to more then +/- 1-inch by the end of the match.

You are correct in saying that the inaccuracies would add up, but after the 15 seconds were up, the knowing our position wasn't extremely important. Had it been, we would have probably considered determining the slippage and corrected.

[ESchneider]

We are working on a robot that hopefully will be able to do almost anything in autonomous mode. I have already put together the IR beacons and am working on the Banner Sensors. I do have a question about the banner sensors. Are you supposed to run it through the 5V digital output? We tried doing that and nothing happened. I think it needs 12V to run, but there seems to be no place to put it.

See here for details:

http://nrg.chaosnet.org/uploads/rts....ightsensor#rts