Unmanned Surface Vehicle Modeling And Motion Simulation

The course and track control of unmanned surface vehicle (USV) is important to improve the observational effect of the recon reconnaissance equipment and the multi--mission operational capability. Because of the effects of wind, wave and flow, the unmanned surface vehicle will produce six degrees of freedom movement which has randomicity and nonlinearity. It is difficult of the course, track and attitude control of unmanned surface vehicle, so six degrees of freedom movement model is built for the better control of unmanned surface vehicle.According to the classic MMG’s separated modeling theory and the horizontal body axes system which was developed by Hamamoto, this thesis describes a six degrees of freedom motion equation of unmanned surface vehicle. Through analyzing the hydrodynamic force and moment, the fluid inertia force model, the fluid viscous force model, propeller thrust model and steering gear model are built respectively.Considering the influence of weather and sea conditions, it is analyzed of disturbing force rooting in wind and wave which is on the unmanned surface vehicle. Based on the assumption that the random wind on the sea is steady, the mathematical model of the wind force is given. Based on the hypothesis of Froude-Krylov, interference force on USV is studied in regular wave and wave model is established.Based on the mathematical model of the USV, simulation model is established by MATLAB/Simulink. Through doing the typical turning test in different sea condition for the simulation model, the test results are analyzed. At autonomous navigation of USV in different sea condition, the movement curves of USV’s speed and yaw angle are drawn. By summary and analysis, movement rule of USV is inferred in multiple sea condition and the rationality of the USV’s movement model is analyzed.