Thermal Tactile Presentation Based on Prediction of Contact Temperature

The thermal sensation corresponding to the touching of an object is one of the most important factors in material recognition. In virtual reality or tele-operation systems, thermal display functions should be embedded in order to obtain satisfactory realism. Since our skin sensors are sensitive to rapid changes in temperature, thermal sensations are thought to arise mainly from the rapid temperature decrease that occurs at the moment of contact between our fingers and an object. Based on this consideration, the present paper proposes a new control method for thermal tactile display to simulate the temperature decrease at the moment of contact. The proposed method controls a thermal tactile display based on the prediction of contact temperature, so that the correct temperature decrease can be produced at the fingertip surface. In addition, we herein report an additional method by which to optimize the thermal rendering for individual subjects. In the optimization, the thermal property of each subject is estimated immediately prior to thermal presentation. The experimental results reveal that the tendency of material discrimination for the thermal tactile display is similar to that for real objects, indicating the validity of the proposed method.