Controller design and implementation for industrial robots with flexible joints

Abstract

A control strategy which consists of feedforward and feedback compensation loops is proposed to improve the performance of industrial robots. The feedforward loop is similar to the usual inverse-dynamics compensation. The feedback control loop uses a frequency-domain optimal controller. The design starts from the single-link case and is extended to the control of multilinkage flexible-joint robots. An experimental system consisting of a single-link robot is constructed for verifying the proposed control strategies. Experiments show good performance of the proposed control strategy in stiffening the flexible joint and in tracking desired polynomial-type trajectories.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>