Implementation of PID Controller with PSO Tuning for FES-Assisted Exercise

This paper describes the implementation of PID control strategy for a functional electrical stimulation (FES) in specific rehabilitation exercise known as elliptical stepping exercise. The PID controller is used to regulate the FES in controlling the knee joint torque of the paretic and non-paretic legs of the hemiplegic stroke patient during the exercise. The cadence speed error is used as the control variable and input to the PID controller. The Particle Swarm Optimization (PSO) technique is used to optimize the PID control parameters and the performance is compared to that of the manual tuning. The result shows that the system has good interaction with PID controller in completing the exercise. The result also shows that PSO is an efficient technique in optimizing the control parameters compared to manual tuning. Further investigation of the control and optimization technique will be considered in the future in order to improve the efficiency of the FES-assisted elliptical stepping exercise.