Understanding Dynamic Human-Robot Proxemics in the Case of Four-Legged Canine-Inspired Robots

TL;DR

This paper tackles how quadruped, canine-inspired robots should navigate human proxemics in dynamic environments. Using a motion-capture setup with the Spot robot, it implements a 2×4 within-subjects design (Movement: Forward, Sideways, Backward, Stationary; Gaze: On/Off) with $N = 32$ participants to measure the minimum social distance maintained during close-proximity interactions. The study finds that sideways movement and robot gaze significantly increase proxemic distance, while the robot facing its task with no gaze minimizes distances; stationary postures unexpectedly elevate perceived risk, and robotics experience tends to increase caution, though not significantly. These results advance understanding of socially acceptable behavior for quadruped robots in real-world settings and inform design guidelines for safe, comfortable human–robot cohabitation in healthcare and outdoor operations.

Abstract

The integration of humanoid and animal-shaped robots into specialized domains, such as healthcare, multi-terrain operations, and psychotherapy, necessitates a deep understanding of proxemics--the study of spatial behavior that governs effective human-robot interactions. Unlike traditional robots in manufacturing or logistics, these robots must navigate complex human environments where maintaining appropriate physical and psychological distances is crucial for seamless interaction. This study explores the application of proxemics in human-robot interactions, focusing specifically on quadruped robots, which present unique challenges and opportunities due to their lifelike movement and form. Utilizing a motion capture system, we examine how different interaction postures of a canine robot influence human participants' proxemic behavior in dynamic scenarios. By capturing and analyzing position and orientation data, this research aims to identify key factors that affect proxemic distances and inform the design of socially acceptable robots. The findings underscore the importance of adhering to human psychological and physical distancing norms in robot design, ensuring that autonomous systems can coexist harmoniously with humans.

Figures (6)

• Figure 1: A participant interacting with our quadruped robot, with the trajectory recorded by a motion capture system.
• Figure 2: Design of the experiment: 1) OptiTrack Cameras, 2) Spot Trajectory. The Spot will always move from B to A if not still. Without gaze, in forward conditions, the Spot is facing A point; in sideways conditions, the Spot is vertical to line AB, facing the participant side, and in backward conditions, the Spot is facing B point. The head of the Spot will always face the participant in gaze conditions. 3) Participants' assumed trajectory. The participants will always face the dotted line direction at the beginning and move from C to D, and they can choose their own paths while moving.
• Figure 3: Rigid body markers on Spot and participants
• Figure 4: Experimental Setup.
• Figure 5: (a): Trajectories of a single participant. The orange fixed trajectory for Spot, other colored trajectories for humans, and the time-synchronized minimum distances are labeled as dotted lines in the plot.