Research On The Virtual Assembly Technology Based On Touch

The mid 90's in 20th century, the emergence of the virtual product development (VPD) technique caused the extensive concern of the researchers. The basic thought of VPD technique is that people simulate and predict the product feature, performance and manufacturability through the computer with the virtual model. During the development of the product, the person can conceive, design, manufacture, test and analyze the product to work out the existing problem of product under the virtual environment. VPD implementation requires a range of support tools, virtual assembly is one of the core technologies.The virtual assembly simulates the thtee-dimensional assembly process of the product realistically based on the shape features and precision features of the product design, and allows users to interactively control the three-dimensional assembly simulation process of the product and test the assemble-able of the product. This definition focuses on the simulation of the assembly process of the product.The Virtual assembly is an important part of virtual manufacturing. People can validate the correctness of the assembly design and assembly operation for early discovery of problems in the assembly process through the Virtual assembly. The Virtual assembly display assembly process through visual.This thesis studied several key technology of Virtual assembly. First, studied the open-source 3D graphics engine, Open Scene Graph(OSG), including graphics framework, scene graph technology for scene management, stereoscopic display principle, the principle of the virtual camera and how to use flexibly. Secondly, in order to display the computer-generated three-dimensional digital image in real-time on an ultra-large projection walls, so that spectators and participants can have an immersed sense. The system uses a multi-channel splicing technology. The thesis studied flat screen splicing technology and ring screen splicing technology. Thirdly, based on the analysis of a variety of collision detection algorithm, the thesis studied the Open Dynamic Engine (ODE) and described the combination of OSG and ODE. The system used OSG for rending and ODE for collision detection, and build ODE collision geometry through the geometric information extracted from the geometry model. In the simulation process, simulation step size can be adjusted to improve the accuracy of collision detection. Fourthly, in order to improve the interactivity, system used data glove and position tracker device, the thesis studied the interface development of 5DT data glove with 14 pairs of contact point, Fastrak and Patriot two kinds of location tracking device.The research result has been used in the multi-template virtual assembly system successfully. This system is suitable for any group of assembly model which meets the requirements, it uses multi-angle display and has the advantage of real-time, interactive convenient.