“Virtual fixtures”: perceptual overlays enhance operator performance in telepresence tasks

Abstract

Virtual Reality and Telepresence systems are human interface platforms which immerse users in environments other than the direct physical surroundings. Operator performance within such immersive environments is generally poor. The typical design strategy for improving the effectiveness of immersive systems has been to increase the physical accuracy of the representation. Most telepresence research has focused on increasing the fidelity of the link between the operator and the remote site. Most Virtual Reality research has focused on increasing the realism of the representation. Although enhanced physical accuracy can improve human activity in a simulated reality, such work often leads to ineffective or inefficient designs due to misunderstandings about the nature and content of reality. This dissertation takes a step back, asks basic questions about the nature of reality, and proceeds with an alternative approach to designing effective immersive systems. When developing immersive environments, designers often slip into naive realism in which they wrongfully equate reality with the physical properties of their surroundings. The design methodology introduced here, Design-for-Perception, proposes that reality is a perceptual rather than physical realm. It asks designers to maintain a strict separation in their thinking between the physical and perceptual worlds. Once designers accept that humans only have access to a highly abstract perceptual representation of their surroundings, they can produce more effective and efficient immersive environments by directly designing for perceptual reality. Application of the Design-for-Perception methodology has led to an innovative method of enhancing operator performance in telepresence environments. The traditional approach to improving teleoperator performance has been to increase the fidelity (physical accuracy) of the link between operator and remote environment. An alternative solution implied by Design-for-Perception is to enhance operator performance by directly embellishing the user's perceptual reality. Perceptual-Overlays are defined as abstract perceptual cues which are introduced into a user's perceptual reality as virtual constructs overlaid on top of the information reflected from the remote site. Because the notion of perceptual overlays is difficult to conceptualize, the Virtual Fixture metaphor was formulated to characterize these abstract percepts as concrete entities overlaid on the remote environment.