Design And Hydrodynamic Performance Research Of Multifunctional Underwater Vehicle

With the development of economy and the advancement of technology,robots are coming into use in all aspects of human life.As a useful tool for underwater exploration,deep-sea operation,underwater vehicles have also developed rapidly.Complex underwater environment and construction requirements promote the production of different types of underwater vehicles,there are small underwater vehicles that can do detection missions in shallow waters and be applied to entertainment,education and so on;there are medium to large underwater vehicles which can operate in the deep sea;there are also manned underwater vehicles that can carry people for scientific research in the ocean.Combined with my own ability and the project requirements of the research group,this article puts forward the concept of multifunctional small underwater vehicle after investigating the development status of underwater vehicles at home and abroad,it has the function of swimming in water and moving along the bottom and vertical wall surface,then the development of the whole machine and its hydrodynamic performance analysis were carried out.The structure is the skeleton of robot,good structure design is not only convenient for later processing and transformation,but also can improve the performance of underwater vehicle.Because the requirement of speed performance is not high,so the frame structure design was chosen.In the structural design,we have completed the selection of all parts,considerations of performance,determination of structure size and layout location.Then the overall structure design of underwater vehicle is completed by using the three-dimensional software CATIA.The control system is the core of the underwater vehicle,the multi-functional underwater vehicle system is divided into two parts.One is the control of ROV(Remotely Operated Vehicle),one is the control of tracked mobile chassis.The control of ROV selects a widely used drone control system.Then the paper has completed the selection of the performance and the determination of the quantity of the propeller.By comparing the effects of different arrangements on the mot ion performance of the underwater vehicle,the arrangement of four propeller in horizontal and vertical directions is determined.The control of tracked mobile chassis is simple.First,in order to select the appropriate motor,the basic parameters of the motor of the mobile chassis is determined according to the specific working conditions.Then two motors are controlled to realize the forward,backward,left and right functions of the underwater vehicle by independent programming.From the structure design to the system construction,the completed assembly of the prototype needs to verify the overall performance.Through the tests on shore and underwater trial experiments,it is shown that the performance of the multi-functional underwater vehicle has reached the initial design requirements and fully meets the underwater detection task of about 100 meters.At the same time,the multifunctional underwater vehicle experiment also provides help for the design of floating body.In the process of hydrodynamic research of multifunctional underwater vehicle,Fluent was used to analyze the surrounding flow field during the direct underwater navigation of the vehicle,and it was found that the shape design of the square floating body brought great resistance to the underwater vehicle,which greatly affected its motion performance and stability of control.By redesigning the shape of floating body and comparing the changes of the optimized flow field,it was found that the streamlined shape reduces the resistance of the vehicle,improves the flow field around the vehicle and athletic performance.