Tuning PID Constants Over a Range

[Jared Russell]

Originally Posted by thatprogrammer

Am I correct in my assumption that, given that the equation of the arm's torque (thanks to Austin Schuh for providing this equation!) is: torque = J * d^2 (theta) /dt^2 + F_gravity * r * cos(theta), that can be subtracted when going down to account for that fact that your motors are not fighting the force of gravity being applied on the arm? In other words, when going up, you need to add to account for gravity pushing down on your arm, but you can rely on this force to assist in pushing your arm down when your motors are working to lower the arm?

Yep, that's usually how gravity works