Ensuring Stable and Transparent High Stiffness Haptic Interaction Using Successive Force Augmention with Time Domain Passivity Approach

Abstract

Even though a lot of work has been done to improve the stability of haptic interfaces, increasing the impedance range and enhancing the rate-hardness still remains a challenging task. The Successive Force Augmentation approach was proposed to improve the impedance range and rate-hardness of haptic interfaces by introducing an adaptive feed-forward offset to the feedback force, while maintaining the desired stiffness value. In this paper, we modify the Successive Force Augmentation approach to eliminate the push backs resulting from high stiffness haptic contacts and guarantee stability by implementing the Time Domain Passivity Approach in series with the modified Successive Force Augmentation approach. In order to validate the proposed controller, high stiffness haptic interaction and teleoperation with high stiffness virtual fixture experiments on two different devices are carried out.