Application of nonlinear friction compensation to robot arm control

This paper deals with a design of a digital servo controller for a robot manipulator with mechanical nonlinearities. The experimental system is a D.C. motor driven manipulator arm. A model to predict the nonlinear behavior exhibited by the experimental system and a nonlinear controller with Coulomb friction compensator are developed and tested. The effectiveness of the nonlinear controller is certified by designing a linear tracking controller based on this scheme. Experimental and simulated responses are given.