Investigating the Effect of LED Signals and Emotional Displays in Human-Robot Shared Workspaces

2025-09-18

AI Summary

This study investigates the impact of LED signaling and affective displays on nonverbal communication efficacy in human–robot shared workspaces, aiming to enhance collaborative safety and efficiency. Using a Franka Emika Panda robot equipped with an end-effector LED strip and a dynamic facial display on a tablet, we implemented reactive and predictive affective expressions alongside color-coded LED cues. Evaluation employed motion tracking, task performance metrics, and subjective questionnaires to quantify effects on collision anticipation, communication clarity, and task efficiency. Results indicate that affective displays significantly improved human perception of robotic intent and interaction affinity; however, they yielded no statistically significant improvement in actual collision avoidance, communication accuracy, or task completion efficiency. The findings reveal a dissociation between perceptual enhancement and behavioral optimization induced by affective cues in physical collaboration. This work provides empirical evidence and methodological insights for designing nonverbal cues in safety-critical human–robot coexistence scenarios.

Technology Category

• Intelligent Robots: Human-Robot Interaction
• Humans and AI: Interaction Techniques and Devices
• Cognitive Modeling & Cognitive Systems: Affective Computing

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work
• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions

Abstract

Effective communication is essential for safety and efficiency in human-robot collaboration, particularly in shared workspaces. This paper investigates the impact of nonverbal communication on human-robot interaction (HRI) by integrating reactive light signals and emotional displays into a robotic system. We equipped a Franka Emika Panda robot with an LED strip on its end effector and an animated facial display on a tablet to convey movement intent through colour-coded signals and facial expressions. We conducted a human-robot collaboration experiment with 18 participants, evaluating three conditions: LED signals alone, LED signals with reactive emotional displays, and LED signals with pre-emptive emotional displays. We collected data through questionnaires and position tracking to assess anticipation of potential collisions, perceived clarity of communication, and task performance. The results indicate that while emotional displays increased the perceived interactivity of the robot, they did not significantly improve collision anticipation, communication clarity, or task efficiency compared to LED signals alone. These findings suggest that while emotional cues can enhance user engagement, their impact on task performance in shared workspaces is limited.

Problem

• Evaluating LED and emotional displays for robot communication
• Assessing impact on collision anticipation and task efficiency
• Comparing nonverbal cues in human-robot shared workspaces

Innovation

• LED signals for robot movement intent
• Emotional displays via animated facial expressions
• Integrated LED and tablet for communication