I'm implementing a force controller on a robotic arm, where the force input comes from torque sensors in the joints. I have calculated the cartesian force on the end-effector from the joint torques, and I can move the arm by setting cartesian velocities.
I'm trying to make a simple admittance controller to move the arm with as little resistance as possible. The controller can therefore be written most simply as a = 1/m * F. Where we want the virtual mass, m, to be as small as possible. The problem is that since F is derived from torque sensors in the arm, it is not completely independent from the acceleration. Therefore, the acceleration is amplified for each iteration and ends up oscillating wildly.
I have tried putting on a damper C*v on the controller, but it needs a lot of damping to decrease the oscillations, which makes the robot hard to move again.
Any tips on what could be done to get rid of these feedback oscillations?