Proxy-Based Sliding Mode Control of a Manipulator Actuated by Pleated Pneumatic Artificial Muscles

Kikuuwe and Fujimoto have introduced proxy-based sliding mode control. It combines responsive and accurate tracking during normal operation with smooth, slow recovery from large position errors that can sometimes occur after abnormal events. The method can be seen as an extension to both conventional PID control and sliding mode control. In this paper, proxy-based sliding mode control is used to control a 2-DOF planar manipulator actuated by pleated pneumatic artificial muscles (PPAMs). The principal advantage of this control method is increased safety for people interacting with the manipulator. Two different forms of proxy-based sliding mode control were implemented on the system, and their performance was experimentally evaluated. Both forms performed very well with respect to safety. Good tracking was also obtained, especially with the second form.