A real-time simulation grid for collaborative virtual assembly of complex products

Simulation of collaborative virtual assembly (CVA) processes is a helpful tool for product development. However, existing collaborative virtual assembly environments (CVAE) have many disadvantages with regard to computing capability, data security, stability, and scalability, and moreover it is difficult to create enterprise applications in these environments. To support large-scale CVAEs offering high fidelity and satisfactory interactive performance among various distributed clients, highly effective system architectures are needed. In this paper, a collaborative virtual assembly scheme based on grid technology is proposed. This scheme consists of two parts: one is a grid-based virtual assembly server (GVAS) which can support parallel computing, the other a set of light clients which can support real-time interaction. The complex and demanding computations required for simulation of virtual assembly (VA) operations, such as model rendering, image processing (fusion), and collision detection, are handled by the GVAS using network resources. Users at the light clients input operation commands that are transferred to the GVAS and receive the results of these operations (images or video streams) from the GVAS. Product data are managed independently by the GVAS using the concept of RBAC (role-based access control), which is secure enough for this application. The key related technologies are discussed, and a prototype system is developed based on the web services and VA components identified in the paper. A case study involving a car-assembly workstation simulation has been used to verify the scheme.