Design And Implementation Of Integrated Navigation System And State Observer For Unmanned Surface Vehicles

Ocean contains rich resources,and is considered as one of the decisive factors to establish national status and economic strength.The development of marine high-tech has become the strategic choice of maritime powers.Unmanned Surface Vehicle(USV)has the characteristics of small size,flexibility,high concealment and so on.It is an important tool for the development of marine high-tech,and has been widely used in military and civil fields.Navigation system can provide accurate and reliable real-time state information for ship maneuvering and control decision-making,which is the key to autonomous navigation of USVs.Therefore,this paper takes the USVs as the research object,and the Inertial Navigation System(INS)and the Global Positioning System(GPS)are used to design an integrated navigation system.The data fusion algorithm of multi-sensors is applied to obtain the real-time position and speed information of USVs,and the precision is improved than the single navigation system.Therefore,the research is practically valuable and significant.The main work of this paper is as follows:Firstly,the basic principles and research status of INS,GPS and integrated navigation system are introduced.The combination modes of integrated navigation system are compared and analyzed,and the appropriate combination mode is selected on the premise of considering economic performance and satisfying navigation precision.Secondly,the overall hardware scheme of integrated navigation system for an USV is designed.The hardware experiment platform is successfully built by using micro-electro-mechanical inertial measurement module,global positioning system module,wireless communication module and core controller module.The monitoring interface is designed,which has the functions of data acquisition,data fusion,data transmission and data display.Then,based on position,velocity and acceleration information,a nonlinear observer is designed to estimate the position and velocity information of USVs.The input state stability of the system with measurement noise is proved by Lyapunov stability theory.A simulation platform is built by MATLAB/Simulink to verify the effectiveness of the designed nonlinear observer.The hardware platform of integrated navigation system for an USV is built to verify the experiment.The experimental results show that the designed nonlinear observer can accurately estimate the state information of the USV.Finally,the difficulty in obtaining speed information of an USV is considered.Only based on position and acceleration measurement information,a nonlinear observer is designed to estimate the position and velocity information.The input state stability of the system with measurement noise is proved by Lyapunov stability theory.The simulation results and experimental results verify the effectiveness of the designed nonlinear observer in estimating state information of the USV.