Experimental Results for Force Distribution in Cooperating Manipulator Systems Using Local Joint Control

Abstract

Local control schemes using only position and rate errors to generate control forces are widely used for control of open- chain, serial-link robotic mechanisms, When two or more such open chains interact, closed kinematic chain, redundantly actu ated mechanisms are formed. Recent work has shown that the vector of joint forces produced using a local proportional-plus- derivative feedback scheme for the control of a cooperating manipulator system results in a vector of joint torques with a minimum weighted Euclidean norm. The current work presents the derivation of this force distribution and experimental evi dence to corroborate the analytic results. The data presented are obtained from an experimental cooperating manipulator system developed specifically for use in the application of theo retical control approaches in cooperating hardware systems.