Fuzzy fractional order force control of 6PUS-UPU redundantly actuated parallel robot based on inner model position control structure

Abstract

The 6PUS-UPU parallel robot is a kind of multi-input multi-output, coupled and highly nonlinear system. Conventional control methods are no longer effective for this complex 6PUS-UPU parallel robot. In this paper, the Inner Model Control (IMC) method in the position control loop and the Fractional Order Fuzzy Proportional–Integral Derivative (FOPID) control method in the force loop are investigated. To study the validness of the IMC method and the FOPID control method, their performance is compared with other published control methods under disturbance and noise, such as three-loop control method, PI control method and Fuzzy Proportional–Integral-Derivative control method. The simulation results clearly demonstrate that the robustness of IMC method and the FOPID control method outperform other methods.