Disturbance Torque and Velocity Estimated Observer based Control System for Low-Stiffness Robot Manipulator.

Abstract

The aim of this paper is to clear characteristics of the obsever based robot motion controller, which observer estimates disturbance torque and velocity.Generally, because of perturbation for moment of inertia, gravity, friction, and low-stiffness by its kinematic structures, robot motion becomes worse. It is well-known that the disturbance observer based controller is robust for not only actually disturbance but unknown perturbation. But we have never full knowledge of that observer, today.This paper describes the phisical means of the disturbance torque and velocity estimated observer, at first. Next, it shows how the observer which is used as way of attenuation for additional disturbance, gives influence to not-nominal model. And, I will show the influence of observer and phase-shift for chaging moment of inertia. And for low stiffness manipulators, I will clear that the observer having not-optimal poles gives worse result for motion.