Fig. 14

Overturned posture for rolling locomotion. The robot locates the legs equiangularly and near the body with grounding two legs for the initial overturned posture, as shown in (a). When the legs are located near the body, the overturned posture is stabilized easily since the center of gravity of the body and the legs are on the line perpendicular to the ground, as shown in (b). The supporting columnar linkages of the legs help the robot to roll smoothly