Numerical Simulation Of Course-keeping For Autonomous Underwater Vehicle Under Current Disturbance

High-precision Autonomous Underwater Vehicle play an increasingly important role in pipeline detection,search and rescue,recovery and docking.The ability of anti-current interference is one of the important indexes to evaluate the navigation performance of AUV,and the problem of AUV course keeping is the main bottleneck to improve the anti-interference ability of AUV.The interference of the AUV in the actual work mainly comes from the ocean current in all directions in the complex ocean environment.Therefore,this paper focuses on the motion of AUV under the ocean current and the problem of course keeping under ocean current.Firstly,the numerical simulation of AUV drift motion under the interference of Ocean current is studied.The full appendage geometric model and current model of AUV,propeller and rudder are established.Multi-block Hybrid Mesh Method is applied to mesh generation of the model.Based on CFD and six-degree-of-freedom motion equations,the current model is loaded to simulate the drift motion of AUV.The AUV was tested by direct navigation,and the reliability of the simulation results was verified by comparing the experimental data.The drift data of AUV show that the AUV's attitude angle and trajectory have large deviation under the disturbance of ocean current.If the 0.2 m/s lateral flow affects the AUV's heading angle at 7.8 s,the deviation of 12 degrees can be achieved.Secondly,the numerical simulation of course changing operation for AUV is studied.Based on the rudder motion mechanism and the actual rudder deflection angular velocity,the rudder motion module is set up.On the basis of direct navigation,load the rudder motion module and the rudder UDF to complete the numerical simulation of AUV's course changing operation.The simulation results are compared with the experimental data to verify the validity and accuracy of the numerical simulation.The results show that when the AUV is moving to 8s,the AUV can rotate 13 degrees,rotate 17 degrees per second and reach 0.45 m/s.It can provide data reference for rudder anti-current simulation.Finally,Numerical Simulation of Course-keeping for Autonomous Underwater Vehicle under Current disturbance.Based on the drift simulation and control simulation analysis,the AUV is loaded with the rudder motion module and current model,and the rudder is simulated to resist the interference of 0.2 m/s,0.5m/s lateral current and 0.5 m/s Vertical current.The comparison between the simulation data and drift simulation data shows that the deviation of 0.2 m/s lateral current to AUV's Yaw angle can be quickly offset when the rudder is deflected to 17.8 degrees with 0.2 rad/s,and the AUV's Yaw can be kept It can resist the deviation of 0.5 m/s Vertical current to the AUV's inclination angle,and the deviation of 0.5 m/s lateral current to the AUV can not resist the deviation of the AUV's Yaw Angle.The innovations of this paper are as follows:(1)A set of Dynamic Mesh model is developed to simulate the relative motion of AUV,propeller and rudder.(2)The current model is added into AUV with propeller and rudder to simulate the drift of AUV and its appendages(3)The numerical simulation of keeping the AUV heading with rudder under the action of current.