A legged mobile robot realizes a motion language by a time-series change in an actuator angle or a motion pattern using the four limbs and the trunk. A motion language which includes, for example, a motion pattern which is an approximation of the contour/shape of a character is used, so that even a robot or a human being which does not possess the same motion language database can determine the meaning and character which is indicated by each motion pattern as a result of visually recognizing and interpreting the contour/form which is indicated by each motion pattern. For example, a robot which has stepped into a dangerous working area can give a message concerning, for example, the condition of the working area to an observer at a remote location without using any data communications means. The legged mobile robot communicates by moving the limbs and/or the trunk. <IMAGE>
Humanoid robot communicating with body language