A 3-step set-point control algorithm for robot arms

Abstract

For robot arm set-point control, a novel PD based algorithm for the estimation and compensation of gravity force and static friction is proposed. Based on the linear-in-parameter property of the gravity force and the steady state feature of PD set-point control, the algorithm modifies the set-points according to the steady state position errors. Using the steady state equations near the given set-points the unknown static friction force and gravity force can be calculated online. This information can then be used to compensate the effects of gravity force and static friction to eliminate set-point errors.