Research On Trajectory Tracking Control Of Unmanned Surface Ships System Based On RISE Method

Trajectory tracking of unmanned surface ships system is a research topic in the field of control.Due to the characteristics of the ships and environment,Inevitably there are model uncertainties,unknown disturbances,input saturation,input delay and so on.These factors will obviously reduce the dynamic and steady state performances of the unmanned surface ships system,which makes the trajectory tracking controller design of the unmanned surface ships system very challenging.Therefore,the research on trajectory tracking control of unmanned surface ships system has important theoretical significance and application value.This article mainly focuses on the full actuated unmanned surface ships system as the research object.Aiming at model uncertainties,unknown disturbances,input saturation,state and input delays,the robust integration of the signal of the error(RISE)method is combined with hyperbolic tangent function,partial differential equation(PDE)and optimal control to design trajectory tracking controllers of unmanned surface ships system.The main results include:1.Aiming at trajectory tracking of unmanned surface ships system with unknown environmental disturbances and input saturation.Based on the combination of RISE and integral backstepping,a new auxiliary filter structure is proposed by using hyperbolic tangent function,which can effectively compensate input saturation and suppress unknown disturbances.In order to deal with the discontinuous dynamics contained in the tracking error system,this paper uses Filippov solution and differential inclusion theory to yield the semi-global asymptotic tracking of the unmanned surface ships system under the designed continuous tracking controller.2.Aiming at trajectory tracking of unmanned surface ships system with unknown disturbances,model uncertainties,state and input delays.A trajectory tracking controller is designed by combining RISE and PDE to compensate the input and state delays and suppress unknown disturbances and model uncertainties.The Lyapunov-Krasovskii(LK)functional is constructed to analyze the stability of the closed-loop system and realize the uniform ultimate bounded of the trajectory tracking error.3.Aiming at trajectory tracking of unmanned surface ships system with unknown disturbances and model uncertainties.Firstly,all dynamic terms of the system are temporarily assumed to be known for feedback linearization,the controller is designed based on the Hamilton Jacobi Bellman(HJB)optimization method to minimize the given quadratic performance index.Secondly,there are parametric uncertainties and unknown disturbances in the system,the controller is modified to a RISE feedback controller which suppress the uncertainties and unknown disturbances.Finally,Lyapunov stability analysis is used to ensure that the controller asymptotically converges to the optimal controller,yields and optimizes the semi-global asymptotic tracking of the unmanned surface ships system.