Quote:
Originally Posted by Kruuzr
We have our PIDController now up and running with either the z axis of a joystick or the x offset of a camera (same ranges) to give it its input (PIDSource). Last night, we had the turret tracking the ball pretty well. Time to tweak the PID constants 
If you don't have a turret position sensor device of some sort, you can still incorporate the limit switches into the PID controller setup. In your PIDSource object, check the limit switch for the direction you are turning toward. If closed, return a 0.0 to stop the motor. If you're still getting some 'jitter', you can set a flag for the direction you were travelling to keep the output 0 until you start trying to track toward the other direction. The problem with just limit switches is that you can't start slowing down before the end stops.
One more thing that just struck me... If you're trying to use Set statements for the same Jaguar that the PIDController is using, you will be fighting it. The PID loop runs every 50ms. You can set it to 0, but the PIDController will shortly overwrite it.
Steve C. |
We finally got our robot integrated Saturday and took it out for test runs and practice and it turned out my PID loops just did not work. I tried to fix it for several hours and never could get the turret to move towards the center of the camera view. I finally called it quits Saturday night, and Sunday morning just set the motor speed to be equal to the camera X-axis difference.
I put a speed cap on the turret and it now works good enough for our purposes. I had the same problem with the PID controller stuff on my turret when it was trying to goto a position stated by another potentiometer. I don't know if I just don't understand the language good enough to debug it, but this year's experience has tailored my expectations from now on. I'll probably still try to get PID stuff working on future robots (as I have for the last 3 years), but I'll always have a backup plan to fall back on like I did this year. Our turret is now driven by joystick and the camera routine works adequately enough to zero in on a target once the user gets it close.