Quote:
Originally Posted by euhlmann
The operation (180 - angle) will fix the problem by changing the clockwise angles to counterclockwise ones, but OP probably doesn't want to do that because clockwise is the convention. Instead, it's a better idea to flip the output direction.
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Quote:
Originally Posted by ollien
Isn't that what negating the PID output would do?
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While the camera will drive to the same location with both of these changes, the reasons and behavior will be different.
By reversing the angle, the physical orientation will move to the correct location, but it will continue to oscillate around that new point, for reasons given in post #2 - Even if it were started right at that physical point at rest, the PID is 180 degrees off target, and will push it one way or the other, starting an oscillation.
If the PID output is negated (or the motor wires swapped), the motor will then be driven towards the desired set point, and the PID should (after a bit of tuning) function as desired, either approaching the set point asymptotically or slightly overshooting with a dampening oscillation.