Preventing Tumbling With a Twisting Trunk for the Quadruped Robot: Origaker I

The tumble stability indicates the capability to resist the tumble caused by disturbances. For a quadruped robot, the tumble is mainly about the line segment connecting two supporting feet. The tumble stability of quadruped robots is evaluated by various stability criteria based on forces, moments or energies. Work has been done to improve the tumble stability of quadruped robots. Nevertheless, the previous work to achieve this goal relied on motion of legs. No trunk motions were considered. As a matter of fact, trunk motion is widely utilized by natural quadrupeds. By utilizing trunk motion, the quadrupeds are able to regulate the center of gravity to improve the tumble stability level. This paper for the first time investigates the effect of the twisting trunk on the tumble stability of quadruped robots from the viewpoint of energy. Thus it can be seen that the twisting trunk help improve the tumble stability level of quadruped robots. The relationship between the tumble stability and trunk twisting is to be analyzed mathematically, and help find the maximum disturbing energy that the quadruped robot can bear with a twisting trunk and further direct motion of the trunk twisting during tumbles to prevent any overturning.