Backstepping Approach to Ship Steering Autopilot based on Fuzzy Adaptive Control

For the nonlinear Norbin ship model, this paper provides a new fuzzy adaptive control algorithm based on the backstepping approach and the approximation capability of the fuzzy system constructed by radial basis function (RBF). Employing the Taylor linearization technique, the algorithm can on-line tune all the parameters of RBF (connection weights, centers and widths), thereby the approximation error can be reduced greatly. Moreover, the robust controller is employed to dispel the effect of the approximation error. The asymptotical stability of the closed-loop control system is proved in the sense of Lyapunov function. At last, the simulating results show that the proposed algorithm has better adaptive ability than traditional PID control algorithm.