AN LQG/H-INFINITY, CONTROLLER FOR A FLEXIBLE MANIPULATOR

An LQG/H-infinity controller synthesis is presented for a flexible one-link manipulator with noncolocated sensing, The challenge of the problem lies in the nonminimum phase characteristics and the ill-conditioned nature of the plant, The innerloop LQG controller provides adequate damping to the flexible modes and numerically conditions the system while the outerloop H-infinity controller provides stability in the face of unstructured perturbations. With only tip position sensing and using a fourth-order model, a controller is synthesized, It is tested with an eighth-order model of the plant and is found to satisfy both performance and stability requirements.