The Research Of Underwater Vehicle Used On Marine Ranching

With the gradual decrease of global lands and the deterioration of environment,coupled with the increasing population of the world, every country around the worldturns their focus of economic development into the ocean. The exploitation of marineresources and the development of marine economy have become the important pillars ofthe national economy of coastal countries. As a new type of large artificial fishinggrounds, the mode of marine ranching that development and governance can proceedsimultaneously gets more and more recognition and praise from all over the world.During the development of the marine ranching, the monitoring equipment which isspecialized for marine ranching is becoming more and more important. Although thereare many different kinds of underwater vehicle at present, due to the environme ntalcharacteristics and narrow space of the marine ranching, they are not suitable for themarine ranching.A vehicle which is targeted and flexible is redesigned according to the complexenvironment of marine ranching. In this paper, the propulsion syste m of commonvehicle is improved. And a new kind of steering system and ups-downs system areproposed and designed in this paper. On the basis of the analysis of the advantages anddisadvantages of typical underwater vehicle at home and abroad, combined with thecomplicated environment of marine ranching, the propulsion system, steering systemand ups-downs system of the vehicle are redesigned, so that it can adapt to the complexenvironment and narrow space of the marine ranching.First the overall design of the vehicle is devised. a new kind of steering system isproposed and designed, whichcansteering onthe spot so that the vehicle don’t need toomuchspace while it’s steering. This new kind of steering system turns the three freedomdegree of the common underwater vehicle into two freedom degree, which simplifiesthe model of the underwater vehicle. The piston system is used in ups-downs system, which can keep the underwater vehicle horizontally suspended in the water withoutdriving force. At the same time it can lower the center of gravity of the vehicle, increasethe vehicle’s stability. Most underwater vehicles are driven by two propellers and thepropellers are driven by two different motors, but the propellers of the vehicle in thispaper are driven by one single motor, which can guarantee straight advance of theunderwater vehicle. At the same time the driving force and the resistance are analyzedin detail. The speed, acceleration and displacement formula are deduced.On the basis of the analysis of the effect of external forces and torque, thekinematics and kinetic models are deduced; the analysis of kinematics and dynamics aredone. The simulation structure is designed according to its kinematics and kinetic model.The transfer function of the vehicle is deduced, and then the closed-loop transferfunction of the whole system is deduced. The simulation structure is designed accordingto the closed-loop transfer function. Through the simulation, the effective PID controlparameters are concluded. According to the simulation results, the feasibility of thekinematics model was verified.The FLUENT dynamic analysis is done to the basic movement of the underwatervehicle. The stress nephogram, velocity nephogram, the velocity vector, the resistanceand resistance coefficient is deduced. Combined with the forces analysis of theunderwater vehicle, an analysis is done to the result of the FLUENT dynamic analysis,and the conclusion of analysis is given. According to the result of the FLUENT dynamicanalysis, the further optimization design of the vehicle is put forward.