Improving the usability of a virtual assembly environment with the integration of multi-sensory feedback

Virtual assembly environment (VAE) technology has the great potential for benefiting the manufacturing applications in industry. Usability is an important aspect of VAE. This paper presents the evaluation of the usability of our developed multi-sensory VAE. The usability evaluation is in terms of its three attributes: (a) efficiency of use; (b) user's satisfaction; and (c) reliability in use. These are addressed by using task completion times (TCTs), questionnaires, and human performance error rates (HPERs), respectively. A peg-in-a-hole and a Sener electronic box assembly task cases have been used to perform the experiments, using sixteen subjects. The outcomes showed that the introduction of 3D auditory and/or visual feedback did improve the usability. They also indicated that the integrated feedback (visual plus auditory) offered better usability than either feedback used in isolation. Most subjects preferred the integrated feedback to either feedback (visual or auditory) or no feedback. The subjects' comments demonstrated that non-realistic or inappropriate feedback had negative effects on the usability, and easily made them feel frustrated. The possible reasons behind the outcomes are also analysed.