The Use of Virtual Fixtures as Perceptual Overlays to Enhance Operator Performance in Remote Environments.

Abstract : This report introduces the notion of virtual fixtures for use in telepresence systems. Tools and fixtures in the real world (e.g., a ruler guiding a pencil) enhance human performance by guiding manual operations, providing localizing references, reducing mental workload, and increasing precision. Virtual fixtures are computer-generated percepts overlaid on top of the reflection of a remote workspace which can provide similar benefits. Because such perceptual overlays are virtual constructions they can be diverse in modality, abstract in form, and custom tailored to individual situations. This study investigates the potential of virtual fixtures by implementing simple combinations of haptic surfaces and auditory sensations as virtual perceptual aids in a standardized telemanipulation task. Subjects viewed the remote environment through a vision system while wearing an upper-body exoskeleton. Eight subjects controlled a slave robot arm to perform standard Fitts' law peg-insertion tasks with and without the aid of a variety of virtual fixtures. Fixtures composed of haptic and auditory perceptual overlays increased operator performance up to 70%. Simple fixtures devised from basic elements can be powerful perceptual aids; a workstation environment might be developed to allow a teleoperator to design and implement virtual fixtures interactively.