Command-filtered recursive sliding control of MIMO nonlinear systems with actuator saturation

We report an antiwindup command-filtered-based adaptive scheme for multi-input multi-output(MIMO) nonlinear systems with actuator saturation. Command-filtered based recursive sliding mode control(RSMC) is designed to achieve adaptive feedback control and command following, while a fuzzy system is employed to approximate uncertain functions of virtual signals in each error surface. To avoid windup caused by unknown input saturation, the fuzzy neural network(FSNN) compensator is added to perform as active disturbance rejection term in the feedforward path. Moreover, tracking differentiator(TD) is employed in RSMC controller to avoid “explosion of complexity” in traditional adaptive method. Simulation results of numeral examples indicates that the derived scheme effectively compensates for the disturbance caused by saturation nonlinearity in the presence of system uncertainty.