TOWARD UNIFICATION OF CONSTRAINED MECHANICS AND VIRTUAL FIXTURES IN HAPTIC RENDERING

Virtual Fixtures (VF) are defined as haptic or visual aids in assisting users of virtual and tele-operation environments during various tasks. They have been mostly defined similar to physical fixtures which are used in performing daily tasks such as holding-on to the railing when climbing the stairs or using a ruler to draw straight lines. Such analogous definitions can be even extended to the case of learning certain manual tasks under supervision, e.g. when one holds the child's hand in order to teach the association between the mouse movements and positions of cursor on the screen. This paper presents how notions from the computational mechanics for solving constrained dynamical systems can be extended for stable implementation of a class of VF in a haptic rendered environment. It is shown that some of the solution methodologies from computational mechanics can have direct implication in haptic rendering of stiff-constrained environment. Examples of such implementations are also presented using a haptic device interacting with a class of VF.