Evaluation of Haptic Collision Feedback and Haptic Guidance for Robotic Teleoperation

Abstract

Introduction: Haptic shared control approaches have been associated with increased performance, while avoiding well-known drawbacks of high automation levels (e.g. out-of-theloop phenomena), as both the human and the automated system can exert forces on the control interface, enabling a continuous interaction between the automated system and the operator. However, little is currently known about the influence of haptic guidance on performance and user experience, especially under varying cognitive load conditions. Method: 26 participants completed an obstacle avoidance-, and a peg-in-hole task in a virtual environment using a seven degrees of freedom haptic device. It was differentiated between three different haptic guidance types and three distinct degrees of guidance stiffness. Moreover, cognitive load was manipulated using a secondary task paradigm. Results: The results indicated that haptic constraints do indeed improve performance by reducing the duration of the task and the distance from the ideal trajectory. Additionally, for the obstacle avoidance task, fewer collisions and lower collision forces could be demonstrated. The best results were obtained with a medium or high degree of stiffness. Whereas especially guidance aiding the user with the positioning of the peg was performance-enhancing with regard to the obstacle avoidance task. Yet for the peg-in-hole task, aiding the operator with the orientation of the peg was most beneficial. Even though haptic constraints remained effective when additional cognitive load was imposed on the user, they generally did not significantly reduced the resulting performance degrading effects. However, haptic guidance was associated with a workload reduction and higher usefulness ratings than manual control. Overall, high enjoyment ratings were evident for all conditions. Yet, a partial trade-off could be observed between the performance-enhancing effects of haptic guidance and feelings of control and responsibility