Design and simulation of self-tuning fractional order fuzzy PID controller for robotic manipulator

Two-link robotic manipulator system is completely nonlinear and time-varying multi-input-multiple output. In this research, the fractional order fuzzy PID (FOFPID) controller is proposed in order to control the robotic manipulator position. Since real control systems are generally nonlinear systems, therefore, better control of these systems requires the usage of an adaptive or nonlinear controller. So we applied a fuzzy system in order to determine the coefficients of a FOPID controller based on particle swarm optimization (PSO) algorithm. In definition of fitness function for this optimization, we considered integral of absolute error (IAE) and integral of absolute change in controller output (IACCO). Finally, in order to compare this controller with the FPID controller, numerical simulations were performed on the robotic manipulator. The results demonstrate that the overshoot of FOFPID controller is less than the FPID and proposed controller has less oscillations amplitude, totally, its performance is better than the FPID controller.