Research On Gait Rehabilitation Training Robot Driven By Pneumatic Actuators

As people's living standards improve, stroke patients are increasing year by year. Every year, the number of new stroke happened is 250 millions in our country, 70% -80% of patients have varying degrees of movement disorder limb, and lose the labor and self-care ability. Body weight supported treadmill training is an effective method for improving the recovery of walking ability. The effects of rehabilitation have been generally agreed by medical experts both at home and abroad. At present body weight supported treadmill training is done hand by hand by the physical therapist to reach the correct walking gait in most of hospitals, this is low efficiency and intensity of work. All of this constrains the efficiency of rehabilitation training and the improvement of rehabilitation methods.In this subject, the gait rehabilitation training robot driven by pneumatic actuators is a new type of device aimed at the existing shortage of body weight supported treadmill training at present. At first this paper summarizes the current research background of the rehabilitation robot, and the applications of the pneumatic system on the rehabilitation equipments and the rehabilitation robots, then put forward the design program of the gait rehabilitation training robot for body weight supported treadmill training. Based on the analysis of normal walking gait, the simulation model of the gait rehabilitation training robot system is set up by using of SimMechanics in the Matlab / Simulink simulation environment, an analytical study is carried out on this robot simulation model, the trajectories of the robot's three joints are obtained as the results. The prototype of the robot driven by pneumatic cylinders and pneumatic muscles is presented according to the trajectory of joints. The high-speed on-off valve is taken as the control element, and the pneumatic actuator's positions are controlled by regulating high-speed on-off valve's duty cycle in PWM mode, thus the robot can guide the patient's legs to move in a preprogrammed gait pattern on the special treadmill. According to the design plan, the prototype of robot's leg which has three joints is produced, and equipped with driven components and sensor components. In the meanwhile, a power driver board is produced; the experimental hardware platform is set up. According to the characteristics of pneumatic system controlled by high-speed on-off valve, the system-driven approach and control strategies are formulated. In the LabVIEW environment, the corresponding software of data acquisition and control is programmed. Based on the prototype platform, the experiments about tracking the target gait trajectory of both one joint and two joints are carried out by using the designed control strategies.Through preliminary experiments, the feasibility and effectiveness of the gait rehabilitation training robot are verified, and the robot has a better prospect for development. In the next step we will focus on perfecting the prototype, expanding and optimizing the function of the system, studying and assessing the effect of rehabilitation in the clinical trial and so on.