VDAS: a virtual design and assembly system in a virtual reality environment

The paper presents a virtual design and assembly system (VDAS) developed in a virtual reality (VR) environment. The VDAS is a VR-based engineering application which allows engineers to design, modify and assemble mechanical products. As a prototype, this system has a knowledge-based library of standard mechanical fastening parts, so a great deal of work is reduced during the product modeling stage. Besides, product models can be directly inserted or modified with a friendly user interface in the immersive VR environment. In order to reach the target of virtual design and integrate VR and computer aided design, the system adopts the variational design approach, so a product model has not only the geometric information, but also variation information and even assembly match information. Finally, the VDAS has the function of assembly planning, and several interactive manipulations, such as part modification, assembly plan verification and modification, have been realized.