Discontinuous spinning gait of a quadruped walking robot with waist-joint

In this paper, a new gait is presented for a quadruped walking robot with waist-joint. Although various types of walking robot have already been developed, their structure and gaits are still quite distinct from the natural walking motion of an animal, and the key point is that animals have waist-joint and use their waist-joint to walk, but, on the other hand a conventional 4-legged walking robot even has single rigid body which has no waist joint. Especially in turning, most animals bend oneself on one side, which makes turn faster and more stable. Spinning gait is very important as same as straight forward/backward gait. All animals need a spinning gait to avoid obstacle or to change walking direction. Therefore, this paper proposes a discontinuous gait for a quadruped walking robot with waist-joint which divides body into the front and rear parts of the body. Firstly, we describe a kinematic relation of waist-joint, the hip, and the centre of gravity of body, and then find the optimal values of parameters to spin most stable with simulation. We implemented a waist-jointed walking robot and showed that proposed spinning gait using waist-joint is more stable than that of a conventional walking robot.