Humans always sway their body when they are standing. Since the swaying is natural for human, they are not conscious of the swaying. However, today, almost all robots are designed to reduce the swaying to ensure stabilities. If communication robots can control the swaying appropriately, it might help humans to anthropomorphize the robot. In this paper, we evaluate how the swaying of a humanoid robot affects human swaying and their impressions. We measured human and robot's neck movement and asked them to answer a questionnaire after the experiments. We discovered that human swaying and impressions were affected by the robot's swaying. Human swaying is always observed whenever communications are performed. In order to apply the swaying to humanoid robots, we only use wheel control. Additionally, we can make the robot's swaying and do other actions on their upper bodies. So the result of this paper will explain how to make robots' swaying.
