If You Are Careful, So Am I! How Robot Communicative Motions Can Influence Human Approach in a Joint Task

TL;DR

This study demonstrates that robot movements can implicitly communicate object properties like carefulness, influencing human approach behavior during joint tasks, thereby fostering spontaneous and effective human-robot interaction.

Contribution

The paper introduces a generative approach to robot motion design that conveys implicit object information, enhancing collaborative communication without explicit signals.

Findings

Humans interpret robot cautiousness through movement cues.

Participants adjust their approach based on robot's attitude.

Motor contagion occurs spontaneously without explicit communication.

Abstract

As humans, we have a remarkable capacity for reading the characteristics of objects only by observing how another person carries them. Indeed, how we perform our actions naturally embeds information on the item features. Collaborative robots can achieve the same ability by modulating the strategy used to transport objects with their end-effector. A contribution in this sense would promote spontaneous interactions by making an implicit yet effective communication channel available. This work investigates if humans correctly perceive the implicit information shared by a robotic manipulator through its movements during a dyadic collaboration task. Exploiting a generative approach, we designed robot actions to convey virtual properties of the transported objects, particularly to inform the partner if any caution is required to handle the carried item. We found that carefulness is correctly interpreted when observed through the robot movements. In the experiment, we used identical empty plastic cups; nevertheless, participants approached them differently depending on the attitude shown by the robot: humans change how they reach for the object, being more careful whenever the robot does the same. This emerging form of motor contagion is entirely spontaneous and happens even if the task does not require it.