Putting Real Feeling Into Virtual Reality

SO FAR, WORKING THREE-DIMENSIONALLY ON A COMPUTER HAS BEEN MAINLY A TWO-SENSATION EXPERIENCE--images and sound. Only a few laboratory systems enable users to feel what's happening on the screen--and then from just a limited range of straight-line movements, such as forward and backward.

Now, researchers at Carnegie Mellon University's Robotics Institute have developed a prototype device that operates with six degrees of freedom, allowing more complicated movements. To provide a richer feel and a more realistic experience, CMU researchers Peter J. Berkelman and Ralph L. Hollis turned to magnetic levitation. The system's key component--something like a car's transmission--floats in magnetic fields. Unhampered by the mechanical pulleys and gears used in other sensory-feedback systems, Hollis' device can handle more complex movements and do so more sensitively.

With the control stick jutting from the top of a desk-top-high box holding the levitation system, a user can guide a virtual peg into a virtual hole and feel simulated forces, as well as friction, as it goes in. The technology could aid engineers in designing products. Hollis believes it will be especially valuable in training surgeons--letting them experience how it feels to cut into a body with a scalpel.