Okiagari-Koboshi type of hopping and moving robot

A new type of small hopping and moving robot, called Okiagari-Koboshi, is developed and a method for hopping and moving control of the robot is proposed. The body of the robot is a somewhat thin elliptic cylinder so it moves only on one or the other side. The robot stands straight with no help and recovers itself quickly to the original stable position by righting moment even under an arbitrary impulsive force. In this sense the proposed robot is self-stable, or statically stable. The stability is accomplished by the center of gravity existing in a suitable place of the bottom. A small electromagnetic cylinder is used as an actuator for hopping and moving, which generates a thrust. A stepping motor is adopted as an actuator to control the attitude. The stability analysis is presented and the equation of motion is derived. It is demonstrated by experiments that the proposed method is effective.