Output feedback control for pneumatic muscle joint system with saturation input

Abstract

Pneumatic muscle as a relatively new pneumatic component is often applied to some precise and flexible control systems. The precise control accuracy puts forward higher requirements for the controller design of the pneumatic muscle system. To guarantee good performance, unknown input saturation which seems inevitable must be fully considered in the controller design. In this paper, such a control problem is investigated for a pneumatic muscle joint system with input saturation and external disturbance. The auxiliary signals are introduced to compensate for the effect caused by unknown saturation. Furthermore, a filter is constructed to estimate unmeasured system states. Then an output feedback control scheme has been proposed by these auxiliary signals and states filter. Finally, simulation studies are used to verify the effectiveness of the proposed control scheme.