A Suboptimal Reference Generation Technique for Robotic Manipulators Following Specified Paths

Abstract

The optimal reference generation problem deals with finding a tracking velocity versus time profile which will move the end effector of a multiple degree of freedom robotic manipulator through a general spatial curve in minimum time subject to hard actuator torque limits. While reference generation techniques exist which solve this problem, they are typically computationally intensive, limiting their usefulness in practical situations. In this technical brief, a modification is made to the formulation of the optimal reference generation problem, resulting in a slightly suboptimal solution which is numerically simpler than optimal methods. The method is applied to a computer simulation of a two link SCARA type manipulator following a circular path in joint space. Performance comparisons are made with an optimized constant velocity profile as with the true optimal solution.