INVESTIGATION ON VELOCITY PERFORMANCE DEVIATION OF SERIAL MANIPULATORS RESULTED FROM FABRICATION ERRORS

Abstract

Manipulators were adopted in industrial field decades ago, but uncertainty still exists in their performance because of errors produced during the fabrication processes. This uncertainty would deteriorate the performance of manipulators and causes these manipulators unable to meet what are required in their specifications. Although the performance of manipulators has been discussed in many researches, these studies all focused on the positioning accuracy or the kinematic performance over a specific trajectory with or without the influence of fabrication errors. However, manipulators always need to perform tasks with requirements on velocity over its workspace, and fabrication errors always have influence on it. It is not practical to define the performance of a manipulator only based on its positioning accuracy or kinematic performance over a specific trajectory with or without the influence of fabrication errors. To complement this insufficiency, this article utilizes the concept of force ellipsoid to conduct the maximum achievable and sustainable velocity of a non-redundant serial manipulator and evaluates the effect of fabrication errors on the velocity performance of the manipulator over its workspace.