Optimization of workspace through perturbation analysis of rehabilitation cable robot

Abstract

It is well known that planar robots may have singular configurations that can result in a loss of full control the mechanisms. In fact, the uncontrollable area is existed as close to singularity, although the robot is operated inside the analyzed workspace. According to the distance to singularity, this comes from the difference of the sensitivity of singular values to be changed easily through the disturbance. However, the conventional workspace analysis estimated by cable tensions has a difficulty giving you the information of singular value sensitivity. In this paper, we focus on the optimization of workspace through perturbation analysis, which estimates the quantity of linear independence for singular value sensitivity. Accordingly, we show the method of perturbation analysis for a 3-DOF cable-driven parallel robot, and then simulation results of optimized workspace to be made change by the acceptable quantity of perturbation.