Research On The Virtual Reality Techniques Of Gun

In order to improve the efficiency of gun design, this paper presents a virtual realitysystem of gun based on the theory of multi-body dynamics and the technique of virtualreality.The main contents include:①The 3-D solid modeling theory has been researched.According to the complex characteristic of gun structure and contour, the solid model of aself-propelled gun is built by use of NURBS theory.②A VR polygon model of gun is setup. Some converting ways from CAD model to VR polygon model are discussed; thedifferences between CAD model and VR polygon model are also compared. After this, aconverting method from CAD model to VR model is presented. The surface triangle meshis used to describe the CAD model of gun based on the STL format of rapid prototyping.Furthermore, the techniques of hierarchical modeling, LOD, and texture mapping areapplied to the system, which improve the modeling quality.③On the basis of themulti-body dynamic theory, a launching dynamic model of a self-propelled gun is set up.The following contacts are considered: projectile and rifling, barrel and cradle scaleboard,cradle toothed arc and elevating gear. Consequently the dynamic data is obtained. Thismodel can reflect the dynamic characteristics of the gun launching accurately.④In order tobuilt the vertical target dispersion model, some random factors are researched, and arandom number generator is designed. The co-simulation based on interior ballistic,multi-body dynamics, and exterior ballistic is achieved.⑤A complex virtual environmentbased on Delaunay triangulation mode, particle system and stereo sound theory is built, inwhich natural environment, human environment, and some other models for simulation areincluded. The whole virtual scene has good immersion, fidelity and friendly interactivecharacteristics, which can be applied to many areas.⑥A virtual reality system isconstructed. The API function is developed, and the degree of freedom of gun is defined.Under different climatic conditions, the VR model of self-propelled gun is driven in thevirtual environment according to the rules of gun firing. And the whole process of gunfiring is displayed, in which real-time display, fire, and stereo sounds are contained. As anexample, a vertical target test of self-propelled gun is implemented. Researchers cancontrol the gun model and experience the process of firing under different conditions.The simulation results show that this system clearly realizes the gun firing test process, and satisfies the real time requirement of system simulation, so that the costs andthe gun design cycle will be reduced. And researchers engaged in gun design can be donemore efficiently by use of virtual reality technique.