Single-Rod Brachiation Robot

Abstract

In this paper, we propose a new brachiation robot, a single-rod brachiation robot. Brachiation is a method of locomotion that makes clever use of gravity and has been tried to apply to robots. Conventional brachiation robots are multiple-pendulum-like robots that mimic a gibbon. Although the multiple-pendulum-like robot can easily change the length of one brachiation step by joints, it has complex structures and generates aperiodic motions such as chaos. In contrast, the single-rod brachiation robot has the advantages of simple structure and the ability to suppress complex multiple-pendulum trajectories. The single-rod brachiation robot has a disadvantage because it is difficult to adjust the distance to the next bar. However, we can solve it by aerial brachiation, which includes an aerial phase before grasping the next bar. Using the actual robot, we showed that the swinging amplitude could be increased by appropriately moving its center of gravity like a trapeze motion. In addition, using this, we achieved continuous brachiation across three bars and brachiation including the aerial phase with a flight distance of 140 mm.