The Virtual Reality Simulation Of The Underwater High-speed Navigation Bodys Motion Morphology

Supercavitation technology—a Sunday punch of the future naval battle. Research on supercavitation technology's extremely urgent at home now. But it has some disadvantages such as long development cycle, high test cost, complex theoretical study, poor reproducibility, big empirical risk, so its repeating physical experiment is not easy to realize. Virtual reality is becoming a focus of the computer field, standard 3D graphic interface based on OpenGL can realize the virtual reality simulation system of the high-speed underwater navigation body. The system not only can help to understand the real process of the supercavitating vehicle, even more important, it can help researchers to repeat the experiment on the computer platform, to check and screen experiment results, to meet the design requirements. The research is of far-reaching significance, and it can be the basic of virtual reality combat system.In the first part of the paper, there is an introduction of related theories about supercavity, including mechanisms of formation and maintenance, the model of supercavity under the steady state. And there are configuration simulations of supercavity around the supercavitating vehicle under the ideal condition or the condition considering various factors. Then the force analysis and dynamic model of the supercavitating vehicle is shown, considering the change of its dynamic characteristic caused by the cavitation.A controller for the stability of longitudinal motion is designed in the second part. First, a PID controller which system input is just the deflection angle of the cavitation device is proven by MATLAB simulation that it can be easily accomplished to make the longitudinal motion stable. The method using feedback linearization of combined control of cavitation device and empennage and synovial control algorithm are simulated by MATLAB to test control effects. The simulation of the PID feedback control algorithm by VC makes the observation of control effects more directviewing. The study of these algorithms is pioneering in domestic, and can be the foundation of the subsequent research. Its objective is to embody the motion morphology of navigation body veritably in the simulation system, not just to provide a simple animation effect.Next, the virtual reality technology and OpenGL are briefly introduced as the basic of the simulation system, including concepts, characteristics, the elementary rendering pipelines, and the system configuration of realizing OpenGL's virtual reality simulation system using VC. Development purpose, requirements analysis and design idea of the simulation platform are summarized as the guiding ideology of the whole system development with principles and methods of software engineering. And class diagrams are designed for the simulation system, as the premise of completing the software system.At last, according to above-mentioned requirements analysis, this paper finished the simulation system of the underwater supercavitating vehicle. The system's man-machine operation interface is friendly. Its main contents comprise rendering of sea, seafloor and sea surface, drawing of submarine obstacles, drawing, loading and display of the model of the supercavitating torpedo, drawing of the cavitation around the supercavitating vehicle, realization of empennage smoke, dynamic display of the longitudinal motion, view transformation function by keyboard control, and so on.