Study on Coupled Torques in Contouring Control of Articulated Robot Mechanism.

Abstract

Robot manipulators are coupled and non-linear systems which are difficult to control at high speed operation. So the dynamic modeling of robot manipulator is important from the view point of design of contouring control. This paper presents an influence of coupled torque on the trajectory error in the contouring control in open-loop robotic mechanism and closed-loop robotic mechanism. Especially, the contouring control in two kinds of trajectories is investigated. The one is trajectory of straight motion, the other is trajectory of right angled turn motion. In our study, first, the equations of torques are derived from the Lagrange's equations of motion with offset length between arms. Their equations are verified by the experiment of straight motion. As experimental results, the coupled torques of each mechanism are revealed. Next, the influences of their coupled torques on the trajectory error are revealed from the simulation of right angled turn motion. The design procedure are provided for obtaining the influence of coupled torques on contouring control by the simulation in each manipulators' configuration.