Active Disturbance Rejection Control For Ship Path Following Based Terminal Sliding Mode

With the rapid development of large-scale,high-speed and intelligentized ship,the methods of tracking control for ship change with each passing day,meanwhile,ship safety and economic requirements are getting higher.In order to solve the problems on the systemic uncertainty of internal and external disturbances,control input saturation,and lateral drifting,etc.Terminal sliding mode and active disturbance rejection control(ADRC)theory have been combined in the paper to research tracking control of ship,main research contents include:1.The study on the design for path following control of ship:Building desired heading course function,which can ensure the error of ship track converging to zero,to obtain desired heading course,afterwards,desired heading course can be used as an input for heading controller,thus,a closed-loop system can be built to achieve the purpose of ship trajectory tracking control indirectly.The method is independent of ADRC on simulation structure,and complicated path following problem is transformed into a manageable heading stabilization problem,so it can achieve ship path following control.2.The study on algorithm of terminal sliding mode active disturbance rejection control:Optimizing nonlinear state error feedback of ADRC mainly.Considering the uncertainty of ship internal and external disturbances,extend state observer(ESO)in ADRC is used to estimate and compensate disturbances,nonsingular terminal sliding mode(NTSM)and exponential reaching law are combined to design control law,which can ensure the system be stable when enters into the sliding mode,decrease chattering;improve the convergence speed and steady-state tracking accuracy of the system,thus,it can improve control effect.In addition,fast terminal sliding mode(FTSM)switching surface,which combines the advantages of ordinary sliding mode and nonsingular terminal sliding mode to insure quick response when the system states are far from the balance point.Power exponential reaching law are combined to insure the system is globally asymptotically stable,thus further optimizes the control effect.3.Simulation experiments of ship straight and curve path following control rely on a nonlinear ship motion model,which is built under Matlab Simulink environment based on training ship "Yu Long" of Dalian Maritime University,the results verify the effectiveness of designed controller.