Effective Output Patterns for Torque Display

In the previous paper in ICAT2002, we reported that a non-grounded palm-top torque display "GyroCube " was developed. Although it requires no grounding base for supporting the counter torque to the objective one, and consequently is suitable for mobile use, it generates superfluous negative resetting torque after presenting the objective one in terms of principle. When the control voltage is increased uniformly over the operation time to increase the magnitude of torque, the resetting torque becomes stronger as same as the objective torque becomes stronger. It is not clear whether the stronger resetting torque would weaken the effect of the objective torque, or it could strengthen the sensitivity of human palm because of the after-effect of the human sensing system. Therefore we conducted new experiments concerning the above issue. The results are as follows. There was no predominant difference between stronger resetting torque case and weaker one. The minimum torque stimulus the user could sense was approximately 200 [gfcm] in either hands. There was no significant difference in the ways of grasping the device “GyroCube”. One of the applications of such device would be, for example, a haptic navigation system for pedestrians. Key words: haptic sensation, virtual reality, torque feedback devic