Assembly validation in virtual reality-a demonstrative case

Assembly validation is a key part of product design. Current methods, such as physical prototyping are time-consuming and do not offer immediate validation results. Assembly motion simulation systems have been proposed as a solution to this problem. However, widespread adoption of such systems is hindered due to their ties to proprietary computer aided design (CAD) software or expensive and often cumbersome hardware. Recently, virtual/augmented reality (VR/AR) technologies and simulation have been heralded as two of the key enabling factors of Industry 4.0. Collective interests in these technologies by industry and community have brought many low-cost software and hardware tools to the market, which opens a gateway to achieving assembly validation at a much lower cost. This paper presents an assembly validation system that is independent of CAD packages, interoperable and implemented using relatively low-cost and commercially available hardware and software tools. The system features intuitive bare-hand manipulation of part models through a virtual hand model that tracks the hands. Collision detection and physics modelling allow for hand-part and part-part interactions to be natural, thus validating assembly interactions. An assembly feature extraction algorithm has also been implemented to analyse the planar face features of the part models to detect possible mating assembly features between parts concerned. A constraint management system considers identified mating features and determines the allowable motion of parts once constraints are applied and removed. Pulling force is used to facilitate the removal of constraints.