PIDController - control speed vs distance - SetSetpoint

[bmfrc]

Originally Posted by gerthworm

Yah, as you probably are finding out, there are two independent ways to do PID in Java...

Originally Posted by AriMindell

On 1389, we reimplemented PIDController to fit our code design, so I don't have any direct experience with the WPILib...

Thank you guys, while reading the docs and implementing the code your answers really helping and we already implemented the pid controllers. It seems to work fine.

What is the best practice in enabling and disabling the pid controller.
Lets say i want to autonomously drive the robot to point X - SetSetpoint(distance_from_X).
When the robot reach the target and stops, should i disable the controller?
If so, what is the best way to trigger this event?

Thanks.

[gerthworm]

I've seen both done:

-Leaving the controller on will help keep you in the same position. This is often simpler too.
-Turning off the controller (and setting the drivetrain to zero) will assume the robot will stay in the same spot, and yield drivetrain power & computing resources for other tasks to use.

Regardless, the trigger condition I like to use for saying "We are now done using this controller" is:
--Error Magnititude is less than some threshold (say, 3 inches?) and stays that way for a certain time period (say, 0.25 seconds?)