Control of a teleoperation system actuated by low-cost pneumatic on/off valves

For a pneumatic teleoperation system, sliding-mode control laws ensuring both transparency and low switching (open/close) activity of the valves are developed. Each pneumatic actuator has four on/off valves, thus sixteen possible combinations (“operating modes”) for the valves exist but only seven of them are both functional and unique. While previous works have focused on three-mode sliding-based position control of one pneumatic actuator, this paper develops seven-mode sliding-based bilateral control of a teleoperation system comprising a pair of pneumatic actuators. The proposed bilateral sliding control scheme is experimentally validated on a pair of actuators arranged in a force-position teleoperation architecture. The results demonstrate that leveraging the additional modes of operation leads to more efficient and smooth control of the system.