Force display system for manipulating thin flexible objects

Force display or haptic display is the process of applying forces to a user giving the feel of touching and interacting with real physical objects. A force display system consists of three main components, force display device, object model, and haptic rendering algorithm that in real time computes the forces to let the user feel. This paper describes a new haptic rendering algorithm applicable to the case that the virtual environment is deformed according to the interacting forces, which is a very thin wall with negligible thickness. Especially, it is addressed the issues in the force display of tool use, which shows a lot of interesting features different from the display associated with the rigid virtual environment. According to the deformation of the environment, the environmental constraints should be changed in real time and contact states should be checked to compute the force being displayed to the operator. The proposed algorithm copes with this situation successfully. Its effectiveness is experimentally verified using a force display system with a 3 DOF SCARA robot as a force display device