Optimal Point-to-Point Motion Control of Robots With Redundant Degrees of Freedom

Abstract

Control of a kinematically redundant robot arm requires an optimization procedure to determine the motion of the end effector. The criterion for optimization can be minimum motion time, minimum joint displacement increments or a combined merit function specified according to the requirements of the user. Three different methods may be used to perform the computations and obtain the joint coordinate increments for the point-to-point motion control of the robot. The methods are the “direct,” the “pseudoinverse” and the “generalized inverse” methods. These methods are described in detail in this paper, and results obtained with the three methods are compared on the basis of performing simulated tasks. It is concluded that the generalized inverse method is the most suitable, general method for point-to-point control of robots with more than six degrees-of-freedom.