Multivariable Root Loci of Control Systems of Robot Manipulators with Flexible Driving Systems* : Distortion Feedback

Abstract

Flexibility of driving systems produces robot arm vibration. Since vibration decreases the operation efficiency and quality, the prevention of such vibration becomed an important consideration in robot arm control. High-gain feedback of disortion in driving systems at each joint improves the oscillatory behavior of the robot system. By using a theory of multivariable root loci, we present two propositions on the behavior of the closed-loop eigenvalues when the high-gain feedback of distortion is implemented.