Virtual building blocks using a 2.5D-display generating of tactile and force sensations

To develop new equipment for virtual reality, we study a combined display capable of stimulating the muscles and tendons of the forearms and tactile receptors in fingers to investigate tactile and force effects on simultaneous presentation. We arranged the handle of the display like a mouse so that anyone could comfortably use it without a priori knowledge. The present display is comprised of a master arm with a tactile display with a 4-by-12 array of stimulus pins driven by micro-actuators and an articulated manipulator to stimulate the muscles and tendons of the forearms and tactile receptors in fingers. Vertical movement of the virtual tactile pad in the virtual world is controlled in proportion to compressive force applied on the display pad, so that operators don´t get tired during manipulations in 3D-space because their hands are supported by the manipulator. The compressive force is measured by a pressure sensor installed under the actuator array. Operators can work in 3D-space in spite of their manipulations in 2.5D-space. Evaluation experiments are performed using the display to verify its presentation capability. In the experiments, subjects try to build up virtual blocks in a line using the display. A precise building task is impossible for the force-only display because of no relative motion between the hands and the blocks, while the building task is completed by the combined display of tactile and force sensations with higher precision.