On study of design and implementation of virtual fixtures

Virtual fixtures (VFs) can be defined as guiding constraints designed to enhance or assist human performance in a computer-controlled system by providing cues of haptic or audiovisual nature. In this paper we present a new characterization of VFs based on mechanics, and provide a set practical guidelines for the designers of such fixtures from a software architecture point of view. We propose an event-driven approach that facilitates the integration of these guiding constraints in a scene graphed-based environment. In this context some novel implementation of VFs are presented, where users may interact with a single or an assembled set of fixtures. We present two types of force attributes for VF and present their implications in a trajectory-following problem.