Ship Course And Track Integral Sliding Mode Keeping Control Based On Auto Disturbance Rejection Control

In order to improve the safety and economy of sailing ships,this paper adopts a compound control algorithm combining auto disturbance rejection control(ADRC)and integral sliding mode control(ISMC)to design the ship course and track keeping controller respectively for the problem of course and track keeping control in ship intelligent control.Specific contents are as follows:1.The design of ship course keeping ISMC-ADRC controller:second-order nonlinear KT equation,which can describe the dynamic performance of ships accurately,is used as mathematical model of ship motion control.The tracking-differentiator(TD)and the nonlinear states errors feedback(NLSEF)in ADRC are redesigned.The third-order tracking-differentiator is established by using the sign function to extract the ship target course and its differential accurately;The linear extended states observer(LESO)can estimate and compensate the actual course and the total internal or external disturbances on-line;During the design of the nonlinear states errors feedback control law,the integral sliding mode surface function can eliminate the static error and accelerate the convergence rate of the control system;Exponential reaching law can weaken chattering caused by ISMC;The Hurwitz criterion can realize the parameterization of the integral sliding surface function and the linear extended state observer and reduce the parameters of ship course keeping controller.2.The design of ship track keeping ISMC-ADRC controller:to solve the problem of underactuated surface ship track keeping control,an indirect control method is introduced to establish the expected ship bow equation for the target path by hyperbolic tangent function,which convert the ship track control to the problem of the ship course stabilization.During the design of the expected ship course controller,the entire integral sliding mode control algorithm is introduced to shorten the stabilization time and eliminate the overshoot of the control system with large initial error.3.Simulation experiments:ship "Marine" is the simulation object,and the simulation experiments of the ship course and track(line track and curve track)keeping control under different sea conditions are carried out respectively by Matlab.The simulation results of ISMC-ADRC controller and ADRC controller are compared,which show that the ISMC-ADRC controller can follow the target course and track with no static difference quickly and accurately and has some robustness to external disturbances.