Research on Fractional Order Fuzzy PID Control of the Pneumatic-hydraulic Upper Limb Rehabilitation Training System Based on PSO

In this paper, a new type of pneumatic-hydraulic upper limb rehabilitation training system is designed, and the system modeling and control method are studied. The 2DOF fuzzy fractional PID controller is proposed, which provides a new reference for improving the control accuracy of two degrees of freedom pneumatic system. Due to the increase of the regulating parameters of the fractional order controller, a multi-objective particle swarm optimization algorithm is designed to determine the parameters of the control system and optimize the determination process of the parameters. In order to verify the effectiveness of the control method, an experimental study was carried out by building a pneumatic-hydraulic upper limb rehabilitation training system platform. Compared with PID controller, the overshoot of the system controlled by fractional order fuzzy PID controller is reduced by 17.3%. The peak time is shortened about 11.7%, and the delay time of sine tracking signal is reduced about 10.6%. The results show that the control performance of two degrees of freedom fractional order fuzzy PID controller is better than other controllers.