I'm trying to tune a low-friction actuator. This actuator is controlled via a 24peak amp drive.
I'm running into the problem where the system goes unstable prior to reaching good stiffness. I start off with the PID controller having P = 0, I = 0, D = 0 gains. Because this actuator is low friction, I provide a D gain of 1 to start such that energy is removed the system. I then start ramping up the proportional gain in hopes obtaining stiff control.
However, I keep running into the issue where the system seems to go unstable prior to reaching desired stiffness regardless of how much I increase D.
Essentially I need my P gain to grow such that the actuator resists external forces, yet this just causes the system to go unstable.
Does anyone have any tips as to what I'm doing wrong? I'm fairly confident my feedback signal is good (not too noisy) and I know that the drive is beefy enough to generate enough force to resist any attempts of pushing on the actuator.