The Research And Realization Of Underwater High-speed Vehicle

Underwater vehicle with supercavitating technology which is wrapped by cavity and the drag is reduced greatly gets high-speed. Many countries have invested largely in supercavitating drag reduction technology. There are many difficult challenges to develop controllable, maneuvering supercavitating vehicles, such as the unstable dynamic of supercavitating vehicles, the inherently nonlinear interaction forces between vehicle and cavity. The depth control program of based on DSP of underwater high-speed vehicle is presented in this paper. The problems of the modle and design of depth control system of underwater high-speed vehicle are researched thoroughly in this paper. The main works done in this paper are the follows:Firstly, the working principle of underwater high-speed vehicle is introduced, based on the characters of underwater high-speed vehicle, the ways of supercavitating vehicle's control and the configuration of supercavitating vehicle are talked. The depth control system is designed with cavitator as actuator. The function of modules of the depth control system is described. The measuring ways of vehicle's depth and actuator's angle are given.Secondly, according to the domestic and overseas references published, the appropriate coordinate system is selected, the parameters of underwater vehicle is defined, forces acting on underwater vehicle are analyzed. On this basis, using Newton's law and the relevant kinetic theories, underwater high-speed vehicle'nonlinear mathematical model is established, mathematical model is linearized based on small disturbance theory.Thirdly, Based on the linear mathematical model, the open-loop characteristics of underwater high-speed vehicle are analyed. Combining with the advantages of fuzzy control's strong adaptability and PID control's small steady-state error, this paper presents the system for the fuzzy self-adaptive PID control algorithm. The error of real-time depth between target depth of vehicle and the rate of error get a reasonable classification. Using fuzzy self-adaptive PID controller to improve the control performance and get better of the dynamic and static response. The results of simulation show that the controller based on fuzzy self-adaptive PID and traditional PID can meet system's requirements.Comparing the fuzzy self-adaptive PID controller with PID controller, the fuzzy self-adaptive PID controller has stronger robustness when system with uncertainty.Finally, the software and hardware design of the depth conrrol system are designed. In the part of hardware design, the main circuit designs such as DSP control circuit, steering engine drive circuit, logic control circuit, power supply circult are given. In the part of software design, the overall program design of depth control system and the main flow chart are given as well. Then, fuzzy self-adaptive PID control arithmetic module, data traffic module, data acquisition module, steering gear control arithmetic module are discussed in detail. From testing, the response speed and high precision of the electric actuator satisfied system design requirements.