Contributing Factors in Human-Robot Handshake: Compliance, Hand Grip, and Synchrony
Adnan Saood, Adriana Tapus
AI summary
Problem
Most prior research examines robotic handshake factors like compliance, grip, and synchrony in isolation, leaving their combined impact on human perception unexplored. This study asks how these three factors jointly influence the perceived naturalness and comfort of a human-robot handshake.
Approach
The researchers built a tactile-sensorized robotic hand with an adaptive synchronization controller and tested it on 16 participants using a 2x2x2 factorial design that systematically varied arm compliance, grip strength, and motion synchrony.
Key results
- Significant main and interaction effects of compliance, grip, and synchrony on objective comfort
- Strong subjective preference for weaker grip strength and higher arm compliance
- Minimal impact of motion synchrony on perceived naturalness and comfort
- Identification of a perceptual hierarchy prioritizing foundational haptic properties over kinematic adjustments
Why it matters
Provides concrete design guidelines for social robotics engineers and HRI researchers to prioritize tactile comfort over complex motion synchronization when creating human-like robotic interactions.
Abstract
Physical touch, such as handshakes, plays a criti- cal role in human-robot interaction (HRI), influencing perceived naturalness and social presence. This study investigates how arm compliance, hand grip strength, and motion synchrony jointly affect the subjective quality of a human-robot hand- shake. We implemented a fully actuated, tactile-sensorized humanoid hand mounted on a manipulator arm and designed a compliant, oscillatory handshake controller with adaptive synchronization. Sixteen participants experienced handshakes across a 2x2x2 factorial design, varying arm compliance, grip strength, and synchrony. Objective kinematic analysis revealed significant main and interaction effects across all factors. At the same time, subjective ratings showed clear preferences for a weaker grip and greater arm compliance, with synchrony exerting minimal influence on perceived naturalness. These results highlight a perceptual hierarchy in HRI: foundational haptic properties exert the strongest influence on user expe- rience, while advanced kinematic adjustments have limited impact when basic comfort is lacking. This insight provides concrete guidance for designing robotic handshakes that feel more human-like and pleasant.