| Backstepping algorithm is studied in this paper and an adaptive robust nonlinear ship course controller based on Backstepping is also designed.In recent years, increasing importance has been attached to nonlinear control system. Especially nonlinear system geometrical theory came out, which created favourable conditions for the development of nonlinear control theory. Backstepping is an advanced nonlinear controller method based on Lyapunov. which is raised for the first time in 1991 by Kokotovic Backstepping has caused atttract attention in control field, at present it has been applied with adaptive control robust control PID control sliding mode variable structure control fuzzy neural network control and so on. Something about Lyapunov stability and the theorem of Backstepping design method are presented in this paper.As is well known, the model of ship course control system movement has the characteristic of nonlinear. In addition ,due to the variations of the state of load, the speed of ship,and the external diaturbances,there are two kinds of obvious uncertainties, model parameter uncertainties and external disturbance uncertainties. With the above problem,there are the requirements for developing advanced robust and adaptive autopilot. It is more important to apply some more effective control algorithm to the ship motion control field. For the convenience of ship course controller design, the uncertain mathematical model of nonlinear ship movement is presented in this paper, the basic knowledge and control principle of ship course control are also introduced in this paper.External disturbances may make the adaptive controller unstable without considering its robustness, so many new adaptive control methods came out, which make the system with robustness. This paper designs an adaptive robust control method for parametric strict feedback uncertain system. This method based Backstepping algorithm combine adaptive control with robust control. Introducing the new parameter... |
