Research On The Underwater Simulation Of Remotely Operated Vehicle Based On Hydraulic Driving

Presently ROV simulator has been widely used in driver's operational technical training,scheme demonstration of underwater repair work and many other fields. In recent years, with the land resources exhausted, people have turned their attention to the deep sea. Because of the underwater environment is filled with complexity and uncertainty,it becomes difficult for drivers to operate ROV,moreover the impact of drivers' psychological factors will also increase the probabilities of job failure which may easily lead to an immeasurable loss. So people build ROV simulation model to simulate parameters change when ROV works underwater in order to provide the drivers with experience, improve operational level,increase the success rate of the job. Based on this objective, this paper sets up the ROV's main drive system-hydraulic system model and does simulation combined with ROV dynamics model to analysis the changes of ROV operating characteristics when working underwater and provide drivers with technical parameters. This paper studies the following aspects:Firstly, the characteristics and the basic working principle of ROV hydraulic system have been analysized. The parameters of key components will be given. Then the mathematical model of hydraulic motor controlled by servo valve has been built based on power bond. After that building the dynamics model of propeller by studying the ship quadrant map and the propeller test which provided by SMD company. At last estimating the load capacity of five-function manipulater.Secondly, ROV hydraulic system simulation models based on AMESim software have been built. The working principle of the key components has been analysised.By using the method of measuring,calculating and dealing with the batch parameters of the single variables to analysis the response characteristics,the key components' optimal parameters can be achieved. Based on the theoretical analysis and comparison with samples, the models of pump, single propeller, pressure compensation tank, pressure reducing valve and directional valve can be verified to meet the requirement of system.Thirdly, the dynamics model of ROV has been built. By synthesizing the thrust of hydraulic-propulsion, the total thrust of 5 DOF motion can be calculated. After that the motion equations can be established based on hydrodynamic experiments. By decomposing the speed in the motion axis, the speed of each thruster will be get.Lastly, by combining the hydraulic system model with dynamics model, the co-simulation model can be built. By analyzing the conditions of ROV motion and manipulator works under the different signals of valve, the co-simulation model will be proved to be correct. In the end using the methods of changing parameters to analysis how the oil fluid bulk modulus, oil absolute viscosity, the inertia of hydraulic motor and the hydraulic lines impact to the working characteristic of system based on the co-simulation model.