The Key Technology Research And Implementation Of Distributed Virtual Assembly Based On HLA

Virtual assembly technology is one of the most important applications in thedesign and manufacture. In recent years, the significance of theory and worth ofapplication are increasingly important in several areas. It is from the point of productassembly which aims to improving the whole lifecycle and quality of product. Virtualassembly technology is the weakest part in the virtual manufacture. The majorbottleneck of Virtual assembly technology being application is build a high efficiency,quality, and low cost of virtual manufacturing environment, and construct a perfectvirtual manufacture theory system.This paper designed a virtual assembly system based on HLA, it realized theHLA interface standard and set up distributed virtual assembly structure. User canparticipate in interactive assembly through multiple clients to realize the remotemodular assembly. The system can assemble product in time with three-dimensionalvirtual environment, it simulation the appearance, materials, spare parts and internalstructure of the products through rendering engine. It not only faultlessly simulatesthe appearance and function characteristics of the products, but also ensures thefeelings of interaction experience and elegant visual. System realized the integrationand collaborative use of HLA distributed communications technology, virtualassembly technology, the virtual reality technology and relational database. The maincontent of work and results are as follows:（1） The bottom network communication support system based on HLAIn light of the object-oriented point of HLA, the object model has been designedand accomplished in different levels, which could obtain the interoperability andreusability of the emulated parts in high level. This paper concerns the flexibility andexpandability of HLA, constructing one network communication structure based onHLA, which takes usage of CERTI as its operation supporting environment to control the whole products virtual assembly procedure through the uniform HLA orders.Different clients could carry the virtual assembly independently and interactively toassemble extremely complex equipment collaterally.（2） Construction of visualization rendering engine focused on complexproductsVisualization rendering engine is the core and foundation of VR, and thenecessary bottom module of virtual assembly system as well. This paper aims onestablishing3D render engine of complex products to organize, manage and arrangethe3D scene data. On the basis of OpenGL and GPU techniques, the details ofcomplex products and effective simulation could be achieved. Meanwhile, the renderengine could support diverse3D model software and data file formats, includingAutodesk3ds Max、MilkShape3D、Maya and so on.（3） Support of interaction between man and machine in multisensoryBeside the key board and mouse, other interactive tools are also employed,including data glove, position tracker and Kinect. Kinect is one3D camera based onbody feeling, using its functions of real-time capture and Influence identification,which is employed to control the assembly object in the virtual environment throughthe user’s gesture. Data glove is one of the common interactive tools, which also iscombined with position tracker to transmit the people’s hand gesture to the virtualenvironment to collar, move, load and unload the virtual objects.（4） Combination of constraint set and semantic identification on virtualassemblyConcerning on the geometric constraint assembly technique traditionally, thispaper adopts the method on the basis of task levels and semantic identification tocapture the user’s intention and calculate the assembly semanteme. To solve thecollision detection problem, this paper adopt one geometric face hierarchical collisiondetection method integrated with spatial index, which could noticeably enhance thecollision detection efficiency and afford the reference for constraint identificationduring the virtual assembly process.