Study On Adaptive Control Of Ship Course Based On Backstepping

Based on the study of the method of backstepping, this paper designed a ship course adaptive controller,and then sinmulinked the controller when the model parameters was changed and the interference was added to the systerms.Ship course controller is an important research field of ship motion control issues. Many researchers at home and abroad have been make unremitting efforts to improve the maneuverability of the ship. At present, most ship course controller design is still used Nomoto linear model. However, the ship sailing in the speed, loading status, outside interference has always changed, and then there has been a serious problem of nonlinear hydrodynamics, making based on linear model design and the control performance worse. For this problem, the adaptive backstepping design method is applied to ship steering motion control in this paper, through experimental results we can see, the ship course controller designed can solve the problem.Firstly, the history of the development, research situation in present of autopilot at home and abroad were reviewed and summarized. Then, there was elaborated the principle of automatic control of the rudder and the ship motion mathematical model and the direction control for the mathematical model of wave interference, introduced the basic principles and the development of recent years of backstepping, deduced the process to design the controller by backstepping controller and used Lyapunov stability theory demonstrated. Through study heading control of ships, a ship steering control was designed by backstepping. In order to facilitate learning and research, firstly, a ship course controller known model parameters was designed. Then, a ship course controller for ship model that contains external disturbances and uncertain parameters was designed, on the basis of the simulation results obtained satisfactory result. In the design process, integrator was added in order to eliminate the constant static error. Sliding model control showed obvious advantages in dealing with uncertain system. In this paper, a ship course controller was designed based on backstepping and sliding mode control. In the design, in order to improve control accuracy, the steering gear performance was designed as part of the system. The controller has both advantages of two algorithms, and achieved a very good simulation results. It showed that the method of sliding mode control based on backstepping was effective in treating with mismatched uncertainties of nonlinear systems.The ship steering controller was simulated in Matlab's Simulink simulation environment. The simulation results show that the controller can follow the change of the ship course very well, control the rudder angle reasonable change and does not appear frequently operate the rudder. Especially when there is a big perturbation in the ship model, the simulation result is still very well in the case of the same controller parameters. It shows that the controller designed by this method has strong robustness. Then, it explains using backstepping deal with system's nonlinear and uncertainty is a successful exploration...