This paper presents a novel method for generating level-ground walking for a rimless wheel with a controlled wobbling mass. Our rimless wheel achieves level-ground walking by simply controlling the wobbling mass attached to the wheel. We mathematically demonstrate that the controlled wobbling mass generates propulsive effects for the rimless wheel. The walking speed of the rimless wheel can be changed by varying the amplitude of the wobbling mass: thus slow walking to high-speed walking can be realized for the wheel. Moreover, we have developed a robot based on a rimless wheel to show effectiveness of our proposed methods. We then analyze the walking properties with respect to the physical parameters and control parameters of our robot through numerical simulation.

In this paper, we propose a novel speeding-up method for biped walking using a swinging-arms motion based on the principle of an up-and-down wobbling mass. We have shown that biped robots with a wobbling mass can achieve fast walking using an active up-and-down motion of the wobbling mass. We have also shown that the active up-and-down motion increases walking speed of biped robots. We apply this principle to a biped robot with two linked arms like humans for achieving high-speed limit cycle walking. We show that the proposed method achieves high-speed limit cycle walking of biped robots with arms.

In this paper, we propose a novel method for fast limit cycle walking using active control of a wobbling mass. Limit cycle walkers achieving energy-efficient walking have been developed in the last decade. Many researchers have recently studied methods for improving walking speed of limit cycle walkers. In human walking, humans swing their arms according to walking phases and the motion is a regularly symmetric motion about the torso. We consider that this motion is an active up-and-down motion for a mass and improves biped walking speed. We numerically and mathematically show that a biped robot achieves fast limit cycle walking by the proposed method.