Haptic display of contact states

During manual assembly or manipulation of objects, different contact states between the object held by the human operator and other objects in the environment should result in different kinds of haptic sensations to the operator. In this paper, we address haptic rendering by taking into account the type of contact state and the effects of friction and gravity. We present a method to model the haptic force and moment caused by a principal contact between a virtually "held" polyhedral solid and another virtual polyhedral solid. We further describe how to identify a contact state between the virtual objects in real time, which is essential for the corresponding haptic rendering. The feasibility of our methods are verified by experiments.