1. INTRODUCTION
One of the most popular mechanisms for autonomous mobile robots is the wheeled type, but quadruped robots are attracting attention in the field of autonomous mobility because of their great potential for applications in complex road environments such as outdoors [1]-[3]. The quadruped robot has a discrete landing point and can actively step over and avoid obstacles. In addition, it is not restricted in its lateral movement, which gives it a potential advantage over wheeled robots in faster movement in environments where it is difficult to maintain posture, such as rocky, sandy, or swampy terrain.