Producing rigid contacts in cable-driven haptic interfaces using impact generating reels

This paper presents a design for a cable reel that allows a cable-driven haptic interface to produce rigid impacts with virtual objects in a virtual reality setting. The haptic interface studied in this article has three degrees of freedom (3 DOF) and acts as a sword-fighting simulator. In order to obtain sharp impacts with this interface, an impact generating reel is proposed to transmit forces across the cables to a user holding the end-effector (sword). A prototype is presented in order to demonstrate the concept. As a method of quantifying the credibility of these impacts, an accelerometer was mounted on the end-effector, where the cables are attached in order to measure the vibrations caused by these impacts. These vibrations are compared with the vibrations caused by an impact with a rigid material such as steel in order to classify the stiffness of the impacts generated by the mechanism.