Adaptive Fuzzy Prescribed Performance Control of Nonlinear Systems With Hysteretic Actuator Nonlinearity and Faults

An adaptive prescribed performance control method is presented through the use of command filter theory for a class of uncertain systems with actuator hysteretic nonlinearity and unknown failures. The maximum overshoot and convergence rate of the tracking error can be guaranteed by the prescribed performance theory, especially when the unknown actuator failures and backlash nonlinearity occur at the same time. In addition, command filters are introduced to the backstepping design to address a modification that obviates the requirement to compute virtual control derivatives, meanwhile the errors caused by dynamic surface control technique can be compensated. From the Lyapunov stability analysis, it turns out that the proposed control method can guarantee all the signals of the resulting closed-loop system are bounded and better tracking performance can be obtained by adjusting design parameters of prescribed performance in the presence of unknown actuator hysteresis and failures. The simulation results indicate the effectiveness of the proposed method.