How Human Motion Prediction Quality Shapes Social Robot Navigation Performance in Constrained Spaces

TL;DR

This study investigates how the quality of human motion prediction impacts social robot navigation in constrained spaces, revealing that common metrics and assumptions may not reliably predict performance or user experience.

Contribution

It provides a systematic analysis of human motion prediction effects on robot navigation, highlighting limitations of standard metrics and assumptions in real-world, constrained environments.

Findings

Average displacement error is not a reliable predictor of navigation performance.

Human cooperation assumptions often do not hold in constrained settings.

Improving robot efficiency can reduce human comfort and productivity.

Abstract

Motivated by the vision of integrating mobile robots closer to humans in warehouses, hospitals, manufacturing plants, and the home, we focus on robot navigation in dynamic and spatially constrained environments. Ensuring human safety, comfort, and efficiency in such settings requires that robots are endowed with a model of how humans move around them. Human motion prediction around robots is especially challenging due to the stochasticity of human behavior, differences in user preferences, and data scarcity. In this work, we perform a methodical investigation of the effects of human motion prediction quality on robot navigation performance, as well as human productivity and impressions. We design a scenario involving robot navigation among two human subjects in a constrained workspace and instantiate it in a user study ($N=80$) involving two different robot platforms, conducted across two sites from different world regions. Key findings include evidence that: 1) the widely adopted average displacement error is not a reliable predictor of robot navigation performance and human impressions; 2) the common assumption of human cooperation breaks down in constrained environments, with users often not reciprocating robot cooperation, and causing performance degradations; 3) more efficient robot navigation often comes at the expense of human efficiency and comfort.