Structure design and trajectory control on gait rehabilitation training robot system driven by pneumatic actuators

In this paper, a new type of gait rehabilitation training robot system driven by pneumatic actuators is designed, which can guide the patient legs to move in a preprogrammed gait pattern on the special treadmill. The hip and knee joints are actuated by cylinders which position is controlled by regulating high-speed ON/OFF valve´s duty with PWM. The ankle joint is powered by two pneumatic artificial muscles. The partial body weight supported device is also actuated by two cylinders in parallel and the supported force value is set by adjusting the supply pressure. The target gait trajectory is tracked by the coordinating movements of all joints. The gait tracking experiments are also tested with the special control strategies. The feasibility and effectiveness of the proposed gait rehabilitation robot system is confirmed by the experimental results.