Providing force feedback in virtual environments

An integral part of successfully manipulating objects is the sensation of touch or force. Experiments with telerobots (robots controlled at a distance) show that the sensation of force and contact improves the efficiency and accuracy of such tasks. Many believe that the same can be said of tasks in a virtual environment. Unfortunately, it is not possible to actually grasp a virtual object in the same manner as you would a real object because virtual objects are defined in the computer, while the user exists in the real world. Thus, there must be some intermediate device that provides the user with the effects of touch, either through the virtual environment itself or in a physical model of the object, which then communicates information to the virtual environment and displays the virtual object to the user. At the University of Tokyo, we are experimenting with surface display, a method that allows users to directly manipulate an object in a virtual environment by touching a physical model of the object´s surface as presented by an intermediate device outside the computer. We have created a prototype of such a device that measures the force exerted on the surface. We have also implemented control and calculation methods, and have evaluated both the device and the methods in experiments with users. These experiments have validated the concepts underlying our work, and we are continuing to investigate implementation issues