Robust Control in Bending and Torsional Coupled Vibrations of a Flexible Robot Arm

This paper address that the vibration control system design for a flexible arm which possesses bending and torsional coupled vibrations. First, an experimental flexible arm is made which has a rotational shaft driven by a servomotor in one end, and an auxiliary mass connected to the other end so that the center of the stiffness of the arm may not exist on the direction of motion of the auxiliary mass which denotes payload. Three degree-of-freedom (DOF) reduced order model is identified according to Seto’s procedure. Based on the obtained model, robust control design procedure utilizing H-infinity control theory is applied. In the controller design procedure, the uncertainty associated with neglecting high frequency modes is represented by unstructured uncertainty. Computer simulations are carried out and it is clarified that the obtained controller achieved a good performance. The effectiveness of presented modeling method and controller design procedure are verified through control experiments.Copyright © 2003 by ASME