Novel haptic mouse system for holistic haptic display and potential of vibrotactile stimulation

This paper describes a novel haptic mouse system which conveys kinesthetic and tactile information simultaneously in virtual environments. The haptic mouse system can provide 2-DOF translational force feedback, vibration, normal pressure, skin stretch and thermal feedback, all of which are important physical quantities of sensing object´s shape, stiffness and surface properties. The system can simulate small scale shapes and roughness of surface textures using cutaneous cues generated by individual drives of a 6×8 pin array. Since thermal differences among surfaces of virtual objects is one of dominant factors in perceiving texture, a thermal feedback unit composed of a heat conduction plate and a temperature sensor is also embedded into the tactile display system. The developed system can be used as a testbed in psychophysical study on tactile perception. We have investigated the influence of the frequency variation on perceived roughness using the haptic mouse system since vibrotaction has been considered as a key factor affecting perception of fine textures by physiology researchers. In order to find out the relation of roughness and vibration, two psychophysical experiments have been performed. The correlation between the vibration frequency and the texture shows that there are certain transitions of perceived roughness. The experimental results yield that the vibrating stimulus is more effective for displaying a fine surface than static displacement display, and it shows a possibility to display finer texture, exceeding the physical limitation of the device.