Shunji Shimizu, Shuichi Ino, Takeshi Tsuruga, Tohru Ifukube Yuichi Wakisaka and Takashi Izumi

Abstract:
It is an important study subject today to develop the method of realizing harmonious sensation feedback to humans not only in the remote manipulation of robots but also in human interface in general. Many study reports on such sensation feedback are available in the fields of visual and acoustic senses, but very few are available in the fields of force and tactile senses. This paper reports on the design, experimental fabrication and evaluates the usefulness of a new force display using a metal hydride (MH) actuator. The actuator made by the MH alloys is one of a few actuators suitable for putting on human. At first, the differential limen for applied force in human was investigated to obtain the design indices of the force display. Then, two types of experiments were carried out to evaluate the availability of the display. The experiments verified that the experimentally fabricated force display is fully capable of displaying continuous force variations on the sensation levels of about 3.5-15.6dB [S.L.] of force. It also verified that the difference between the force that acted on an arm when the arm actually lifted a real object of 20N and the force that was displayed by the force display and sensed to be equivalent to the force of the real object was smaller than the differential limen, indicating that this force display is capable of giving approximately the same force information as real objects to human. As a result, it was verified that the force display using MH actuators is useful.

Keywords: Force display, Metal hydride actuator, Force sense, Elbow joint, Keinethesis