The effect of gravity on perceived affective quality of robot movement

Abstract

Non-verbal communication, in particular emotions and social signals, has the potential to improve interaction between humans and robots. Body movement style is known for influencing the affective interpretation of a movement in humans. In this paper the effect of gravity on perceived affective quality of robot movement is investigated. Simulations of a robot arm executing various daily tasks were created. Each task is executed under three different virtual gravity conditions: positive (downward directed force), negative (upward directed force) and no gravity. In a user study participants rated videos of the movement of the robot arm in terms of its emotional content. The robotic arm performed ten different tasks. Two response tools were used for the participants to rate the videos: the AffectButton and the Self-Assessment Manikin. Results show that there was a residual significant effect of the virtual gravity variable on the AffectButton. Moreover, there was a large significant effect of task on the ratings of both the AffectButton and the Self-Assessment Manikin. This indicates that gravity has a small, but measurable effect on the perceived emotional content of even a simple, rather disembodied, robot movement.