EXPERIMENTS USING MULTIMODAL VIRTUAL ENVIRONMENTS IN DESIGN FOR ASSEMBLY ANALYSIS

The goal of this work is to investigate whether estimates of ease of p art handling and part insertion can be provided by multimodal simulati on using virtual environment (VE) technology, The long-term goal is to use this data to extend computer-aided design (CAD) systems in order to evaluate and compare alternate designs using design for assembly an alysis. A unified, physically-based model has been developed for model ling dynamic interactions and has been built into a multimodal VE syst em called the Virtual Environment for Design for Assembly (VEDA), The designer sees a visual representation of objects, hears collision soun ds when objects hit each other and can feel and manipulate the objects through haptic interface devices with force feedback Currently these models are 2D in order to preserve interactive update rates, Experimen ts were conducted with human subjects using a two-dimensional peg-in-h ole apparatus and a VEDA simulation of the same apparatus, The simulat ion duplicated as well as possible the weight, shape, size, peg-hole c learance, and frictional characteristics of-the physical apparatus. Th e experiments showed that the multimodal VE is able to replicate exper imental results in which increased task completion times correlated wi th increasing task difficulty (measured as increased friction, increas ed handling distance, and decreased peg-hole clearance), However, the multimodal VE task completion times are approximately twice those of t he physical apparatus completion process, A number of possible factors have been identified, but the effect of these factors has not been qu antified.