Peripersonal Space Tele-Operation in Virtual Reality: The Role of Tactile - Force Feedback

In tele-operated human-robot collaboration, a human operator typically engages with a distant physical environment through a robotic system equipped with multiple sensors and actuators, allowing for haptic-based precise manipulation. Although these technical systems have been in use for years, the connection between multisensory perception and action in peripersonal space during tele-operations remains less understood. To delve deeper into this relationship, we examined distance perception in virtual peripersonal space. Participants wore an HTC Vive head-mounted display (HMD) featuring integrated eye-tracking (SMI) and moved a comparison object (a yellow ball) towards a target object (a blue ball) using a Geomagic Touch haptic device stylus, receiving either force feedback ('closed-loop') or no force feedback ('open loop') during the operation. They were instructed to focus on fixation points while performing the task, with SMI eye-tracking monitoring their gaze. The spatial positions of the comparison and target objects were arranged in four layouts: (i) center-to-center, (ii) centerto-peripheral (20 degrees in visual eccentricity), (iii) peripheral-to-center, and (iv) peripheral-to-peripheral. We employed seven distance levels between the objects in Experiment 1 and five distance levels in Experiment 2, using consistent methods of stimuli presentation. The findings revealed that estimation errors were significantly influenced by force feedback, spatial arrangement, and distance. Crucially, the visibility of themovement trajectory enhanced the effectiveness of tactile force feedback. Overall, this study proposes a potential guideline for human-computer ergonomic design, emphasizing the importance of force feedback for accurate targeting.