3D Surface Presentations of Virtual Tilt Pad Using Moment Measurement for Pin-matrix Tactile Display

Although several actuator principles for tactile displays composed of many micro-actuators exist, current actuators do not produce sufficient stroke and force generation. In order to compensate their shortage ability, we developed a new pin-matrix tactile display in which pin-protrusion distribution synchronizes pitch and roll moments applied to the display. In the present study, we evaluated the versatility of a virtual tilt pad presentation that is a progression from our previous study. In the tilt pad presentation, the rotations around the x-axis and y-axis are managed by the centroid position of the operator's fingers. In the evaluation, the subjects tried to compare the size of two virtual spheres to evaluate the 3D-shape presentation capability of the display. Since the sensation thresholds for each subject were low enough, we proved that operators could appreciate a fine distinction of sphere radii generated by the proposed display. In the case of a relatively large sphere, which is the most difficult case because it has the smallest curvature, the discrimination tasks improved with slight tapping as compared to pressing and rubbing with the fingers. Consequently, the manner of presentation can compensate the shortage ability of micro-actuators.