Improvement of Pneumatic Robot Control Using Disturbance Observer.

Abstract

The low stiffness due to air compressibilty makes it difficult to control a pneumatic robot accurately. In order to improve its control performance, we propose a robust control scheme using the disturbance observer comprising the plant reference model. The disturbance observer estimates both the variations of plant parameters and disturbances based on the control input and the joint angular velocity. The proposed control scheme can decrease the influence of disturbances by means of the feedback of estimated disturbance. Its availability is investigated through simulations and experiments for the robot arms with two joints.