Analyze On Hydrodynamic Response To Multiple DOF Control Of A Remotely Operated Underwater Vehicle Base On Multiple Sliding Mesh

The Remotely Operated Underwater Vehicle(ROV) discussed in this thesis is a complex structure system which consists of cable, robot main body and propeller thrusters. Firstly, a three-dimensional hydrodynamic mathematic model of the ROV in the water is proposed. In the model, the governing equations of umbilical cable are derived from the balance of forces, these equations are established by introducing the boundary conditions at the lower conjunction point between lower end of cable and robot main body and the upper conjunction point between upper end of cable and work ship,then a hydrodynamic mathematic model of the ROV is established.Secondly, Proportion Integral Derivative(PID) control which is applied to design the trajectory and attitude controller on the basis of the hydrodynamic model proposed above. To achieve controlled movement of the robot body, according to the planned trajectory and attitude demands the solving controller will output a corresponding propeller thrust and translate thrust into a propeller speed for hydrodynamic numerical calculation.Thirdly, using Fluent multiple sliding interface to analyze the characteristics of thruster under the coupling flow field of main body moving and propeller rotating, thus we can easily calculate the propeller thrust operated at the robot body influence and other characteristics of the flow field.Therefore it is more accurately to grasp the rules of propeller propulsion in the ROV system.Finally, the combination of Fluent, PID, and Fortran into a control simulation is applied to exchange and share data. We construct the hydrodynamic numerical calculation model by using multiple sliding interface on the simulation platform, and then simulation experiments of the ROV are carried out to analyse the hydrodynamic responses of the ROV, so the numerical calculation method is effective for the ROV hydrodynamic calculation.