Optimum Motion Control of a Redundant Robot with the Objective Function of Dexterity

Abstract

This paper describes an optimum motion control method for robotic serial manipulators with multiple redundant degrees of freedom. The manipulability measure, which is given by a function of the Jacobian matrix concerning the position and posture of the end effector of a serial manipulator, is proposed as the index to evaluate the dexterity of the manipulator, and it is defined as most dexterous when the manipulability measure takes the maximum value. New methods to drive serial manipulators most dexterously, namely the optimum CP control methods with and without consideration of the posture angle of the end effector, are proposed and experimentally examined for planar 3R-, 4R- and 5R-redundant manipulators. Consequently, a better result was obtained by the optimum CP control method with consideration of the posture angle than by the method without consideration of the posture angle : the manipulators were driven most dexterously over most of the driving range, and high response was obtained.