Performance Analysis of a Haptic Telemanipulation Task under Time Delay

There is ample research on the effect of haptic teleoperation under delayed communication channels in terms of stability and system performance. Little attention, however, has been paid to the effect of delayed force feedback on users’ task performance and whether force feedback is beneficial under significant communication delays. This paper investigates whether force feedback improves user’s task performance in delayed teleoperation. We study peg-in-the-hole insertion/retraction, dexterous manipulation tasks involving high degrees of freedom and high forces at certain points during task execution. A user study involving unilateral (without force feedback), bilateral (with force feedback) and graphical feedback teleoperation under various delays is presented. We observed that for all feedback modalities, task completion times increase as delay increases. Haptic feedback helps reduce contact forces and the occurrence of large robot/environment forces. Furthermore, graphical feedback helps users maintain the lowest range of forces at the cost of higher task completion times. With users mindful of minimizing contact forces, haptic/graphical feedback causes the task to take more time than unilateral control. Therefore, when short completion times are crucial given a tolerance for larger forces, force feedback only serves to increase the time required to perform the task; thus, unilateral control may be sufficient. © Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2011