Active Disturbance Rejection Control For Ship Course Keeping And Path Following Based On Sliding Mode

It is adopts the theory of fractional order sliding mode and the method of combining the immunity control theory,to control the ship course keeping and path tracking control is studied,and aims to solve the problem of the underactuated ship course control,and improve the course and track of ship controller in control precision,reduce the overshoot of system,improve the anti-interference ability of the system.1.Design of ship's course keeping controller:the Norrbin model,which can accurately describe the ship's motion performance and contains nonlinear terms,is used as the nonlinear dynamic control model of ship's course control.The fractional sliding mode surface is constructed by the fractional calculus operator in fractional calculus theory,which increases the stability of the system and speeds up the convergence rate.Considering the chattering problem in sliding mode variable structure control,the fractional exponential approach law is introduced to reduce the chattering phenomenon.Combining with the nonlinear dynamic control model of ship course control,the ship course maintenance control law of fractional sliding mode is designed.Internal instability and interference of the system,using the immunity control algorithm of linear extended state observer to estimate the total disturbance and compensation,and through the design of the linear immunity control algorithm of error feedback control law is implemented since the immunity control algorithm with the combination of sliding mode variable structure control algorithm is obtained based on the fractional order sliding mode since the immunity of ship course-keeping controller.2.Design of ship track tracking controller:for the tracking control problem of underactuated ship,the hyperbolic tangent function is used to establish the expected heading equation of the planned track,a course keeping controller is designed to track the expected heading,and the track tracking control problem is transformed into a course keeping control problem.In fractional order sliding mode,on the basis of the immunity heading controller according to the principle of deviation to improve the traditional linear extended state observer,improves the linear expansion of total internal and external disturbance observation precision,by building the expectations of the ship heading equation,the design of the modified since the immunity fractional order sliding path tracking control law,and its stability are verified through the lyapunov stability theory.3.Simulation verification:the 5446TEU container ship of COSCO group is the simulation object.The computer simulation experiments of course keeping control and track tracking control under different sea conditions were carried out by simulink.The fractional-sliding mode ADRC course keeping controller and the improved-fractional-sliding mode track tracking controller are compared with the traditional ones.