Design, Control and Experimental test of Pneumatic Leg Rehabilitation Device for Isokinetic Exercise

In this paper design and manufacture of an experimental setup of rehabilitation device for isokinetic exercises, using pneumatic actuator, is presented. In isokinetic exercises, limb’s movement must be provided at a constant speed. For this type of movements, the actuator should provide an accommodating resistance against patient effort. Therefor the main challenge is speed controller design for actuator in the presence of disturbances logged by patient. This goal is achieved by using electrical actuators at the commercial levels. But beside the high cost of this instruments, low softness of electrical actuators is the main problem of using them in rehabilitation devices. Using pneumatic actuators decrease the final price and benefits the system by pneumatic advantages such softness and high power to weight ratio. This requires overcoming speed control problems in presence of the considered challenges. In this research modeling and speed control of pneumatic actuator has been studied for contraction and expansion mode of muscle. Experimental results take advantages of servo pneumatic actuator for providing isokinetic trainings in leg rehabilitation as well.