What is wrong with my Vision to Gyro code?!

[ollien]

Originally Posted by pblankenbaker

You indicated that your PID loop would rotate the robot to 125 degrees instead of the target of -56 degrees. Given that the robot then oscillates around 125 degrees, this sounds like a condition where you need to invert (negate) the output value produced by the PID before applying it to your motors.

When we run across this issue, we typically observe the following:

• Robot rotates away from target because we are applying power in the opposite direction required to reduce the error.
• As the robot rotates away from the target, the error increases and the power output increases (it typically speeds up as it "runs away" from the target).
• Because the PID set to continuous mode, 180 degrees is the farthest away from the target that you can get (so once it goes past that, the PID probably inverts the error on you and you bounce back hard in the other direction).

Try negating the power before applying it to your motors to see if that fixes the problem.

It might also be useful to add a command that rotates the robot 90 degrees every time you press a button (to make sure you get the rotation PID figured out before adding the camera code).

My team ran into a similar issue when trying to use PID and a NavX to make our robot drive straight. What I was confused about (and still am, quite frankly) is as to how we would get a steady state error 180 degrees from the target. You said in your post that

Because the PID set to continuous mode, 180 degrees is the farthest away from the target that you can get...

If the error is still such a huge value, why wouldn't the PID loop account for that?