bridge balancing

[mikemascot]

hey any one trying to get the end game. Team 316 is we are using labveiw 2011. Any tips?

[kinganu123]

use an accelerometer to auto balance

[dubiousSwain]

we have the robot automatically balancing. teaser coming soon

[mike1010100]

you would use the gyros for balancing more than you would use the accelerometers, as you would want the gyros to be at a 0 degree angle of rotation or within a certain range, instead of the feedback from the robots current rate of motion

also, as a side note, please post that teaser soon, i am also trying to figure out this in Labview and im stuck!

[plnyyanks]

Originally Posted by mike1010100

you would use the gyros for balancing...

But what about gyro drift? How do you handle that and get a foolproof angle? Don't worry - it's not too hard - we've got it figured out already, and we just need some fine tuning on our bridge balancing. I'm sure you can figure it without too much trouble.

Google is your friend.

[mike1010100]

we have two gyros on the robot, one in front and one in the back, and I have taken the absolute values of each of them then taken the difference, put them into an in range and coerce function ect. but I can only either get the robot to try and level itself by either moving backwards or forwards, but not both backwards and forwards until its level, its only going in one direction to do that

[plnyyanks]

How accurate is this combination? Remember that gyros generally give better rate information (as in, a better angular rate while your robot is in motion) and accelerometers give better absolute angles while stationary.

A couple days ago, I set up both a gyro and an accelerometer with LabVIEW front panel graphs and just watched the readings - you should do this too (or your C++/Java debug method of choice). You'll learn something: gyros drift over time. Sometimes it's a really big amount, and sometimes it's only a little. But it's always there. You'll have to find a good way to compensate for it in software and get a really precise angle out of it. I know a few ways to do it, but I'm not going to say. You'll learn it better if you figure it out for yourself.

[DonRotolo]

I'm not a programmer, but if this was my problems to solve, I wouldn't care about absolute gyro angle, just changes. That is, I'd have my driver press a button to "auto balance", and start the process from there.

Oh, wait: If the robot isn't on a bridge, then it might think that level = tilted.

OK, self-calibrate every 5 seconds, and take the average of the last 10 values or something.

Or just tell the driver to press 'calibrate' when the bot is level, within 20-30 seconds of getting onto the ramp.

Programmers: Am I close?