DECENTRALIZED SLIDING MODE CONTROL FOR FLEXIBLE LINK ROBOTS

A technique using augmented sliding mode control for robust, real-time control of flexible multiple link robots is presented. For the purpos e of controller design, the n-link, n-joint robot is subdivided into n single joint, single link subsystems. A sliding surface for each subs ystem is specified so as to be globally, asymptotically stable. Each s liding surface contains rigid-body angular velocity, angular displacem ent and flexible body generalized velocities. The flexible body genera lized accelerations are treated as disturbances during the controller design. This has the advantage of not requiring explicit equations for the flexible body motion. The result is n single input, single output controllers acting at the n joints of the robot, controlling rigid bo dy angular displacement and providing damping for flexible body modes. Furthermore, the n controllers can be operated in parallel so that co mpute speed is independent of the number of links, affording real-time , robust, control.