Abstract:

An adaptive fuzzy backstepping controller design method based on Lipschitz condition is developed to deal with the nonlinear system with input saturation and unknown control direction. Along the controller design process, the transformed style and Butterworth low pass filter are used to solve the problem of the unknown control direction. By using the fuzzy logic system to identify the uncertain nonlinear functions online. The hyperbolic tangent function and Nussbaum are used to handle the input saturation. The backstepping approach is combined with the dynamic surface control technique to solve the problem of “explosion of complexity”. It is shown with Lyapunov stability theorem that the proposed control method can guarantee that all the signals of the resulting closedloop system are semi-globally uniformly ultimately bounded (SGUUB) in probability. Finally, the method is applied for the control design of the attack angle of the hypersonic vehicle. Simulation results show the effectiveness of the presented method.