Design, Development, and Evaluation of a Pinch-Grasp Haptic Interface

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch-grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human-computer interaction, this novel interface is designed for high-resolution contact forces, while centered around a lightweight structure. This functionality renders the device scalable and adaptable to a wide range of haptic interface structures and force level requirements. We present an optimal configuration for a pinch-grasp interface, which produces bidirectional forces to an operator's fingers and a rotational force to the wrist through a cable drive system. The device is characterized for use on a commercial haptic interface through demonstration of sustained peak performance and also workspace utilization. The dynamic performance of the pinch-grasp interface is experimentally determined, and the frequency response is identified to illustrate its contact force resolution.