Research on High Fidelity Haptic Interface Based on Biofeedback

In this paper, we propose a high fidelity haptic interface based on biofeedback. When we interact with a very stiff virtual object in the virtual world by a haptic interface, the haptic interface frequently becomes unstable. We cannot feel the virtual object stably. On the other hand, when we interact with a real object in the real world, the dynamics of our fingers and arm always change and adjust to the appropriate value for the real object. We can feel the real object stably. By using the adaptation, we aimed for achieving the high fidelity haptic interface. In this study, the proposed system measured the grasping force generated by the user interacting with a virtual object by the haptic interface. The system also controlled the coupling impedance between the virtual object and the haptic interface by using the grasping force as biofeedback. In order to measure the grasping force, we developed a new end effector for a string based impedance haptic device SPIDAR-G. We conducted evaluation experiments about the proposed system. The experimental results indicate that the proposed system improved the maximum stiffness of the virtual coupling, and achieved both stability and fidelity by using biofeedback.