Research And Implementation Of USV Navigation Controller

Unmanned surface vessel(Unmanned Surface Vessel,USV)as a kind of intelligent and autonomous marine equipment is the most important part of integrated information system for constructing trinity of sea,land and air dimension by our country in the future,similar to unmanned aerial vehicle and unmanned surface vehicle,which combines multiply high-techs.That is,USV plays an important role in the field of environment detection,hydrologic monitoring,marine charting,marine rights and enemy detection.When it confronts with unknown and complex ocean environment,to design a kind of stable and reliable autonomous navigation controller is one of the important contents of autonomous control.The paper based on "Lanxin"USV of Dalian Maritime University mainly completes the following research work,in order to deal with the problems of underactuation USV autonomous navigation under the circumstance of modeling uncertainty and external disturbance.1.The chapter mainly introduces some fundamental preliminaries including Lyapunov stability theory,backstepping and dynamic surface control(DSC)technology.According to vessel’s modeling,"Lanxin" USV maneuvering motionmathematic models have been made,who are three degree s-of-freedom motion model,maneuvering response model and sea state disturbance model,respectively,Meanwhile,simulation system of maneuvering motion are constructed.2.In the respect of USV’s autonomous heading control,utilizing the nonlinear disturbance observer(NDOB)with the capability of observing system’s uncertainty and external disturbance and introducing DSC to deal with compute explosion,a heading tracking controller has been proposed based on NDOB,which makes equivalent compensation in the process.Numerical simulation results demonstrate the effectiveness of proposed controller in the aspect of heading tracking and disturbance rejection.3.In the respect of USV’s autonomous trajectory tracking control,combining Line-of-sight(LOS)guidance algorithm and heading tracking control algorithm based on NDOB,an indirect trajectory tracking controller has been designed.Simulations are performed for tracking along both straight-line and circular-line.To improve the accuracy of trajectory tracking control,a direct trajectory tracking controller based on NDOB has been designed.Simulations are performed for tracking straight-line.In a word,numerical simulation results demonstrate the effectiveness of proposed controllers in the aspect of trajectory tracking.4.In order to verify the correctness of aforementioned controllers in the actual vessel’s application,an autonomous navigation control platform of "Lanxin" USV is constructed.Furthermore,the software and hardware system of USV heading and trajectory tracking is designed and realized.Experiments in real ocean environment demonstrate that proposed navigation controllers can track heading and trajectory well with great robustness under the complex sea state.