Pushing methods for working six-legged robots capable of locomotion and manipulation in three modes

A working six-legged robot which can switch three modes for locomotion and manipulation was already developed. In its vertical four-leg two-arm mode, lower four legs are used for locomotion and upper two legs for manipulation with its body vertical to the ground. In order to expend capabilities of this robot, a method of pushing a large object in this mode is proposed. The robot holds the object using its upper two legs and body. The robot leans against the object and applies pushing force. Then it walks by moving the outer and inner pairs of the lower four legs alternately. Because of this symmetric walking, the robot can push the object with keeping lateral balance. It can apply large force owing to the effect of its body weight. Because holding the object firmly, the robot can push the object stably without falling down. For comparison, two methods are also analyzed. First the robot simply walks by tripod gait with its body touching the object. Second the robot pushes the object using its upper two legs and walks using its lower four legs in vertical four-leg two-arm mode. Then the merits of the proposed method are clarified. Three methods are experimentally ascertained using the developed robot.