Postural Stability and Motion Control of the Rope-Hopping Robot

In addition to industrial robots for production, a large number of robots for nonindustrial use have been developed recently. For example, they include emergency-rescuing or fire-fighting robots, amusement robots, robots for educational use and robots for security. The authors have no doubt that robots for amusement and educational purposes will have a promising future. Thus, we developed a rope-hopping robot which is a kind of amusement robot. Although rope/hopping is an easy exercise even for young children, there are several difficulties to be overcome if it is to be executed by a robot. The robot developed is composed mainly of one leg, one main body pivoting at the top end of the leg and a double arm holding a rope. Swinging the main body back and forth, the postural stability of the robot in the vertical plane is attained by using feedback control based on the compound center of gravity of the robot. Then the rope-hopping motion of the robot is realized by cooperative use of the leg, the main body and the arms which rotated the rope according to the proposed path. Experimental results show that the control methods for the postural stability and the jumping of the robot together with the path for rotation of the rope around the arms are very useful.