Motion behavior of a 30-strut locomotive tensegrity robot

Tensegrity structure is a prestressed self-equilibrated system consisting of compressed struts and tensioned tendons. The shape and position of tensegrity can be actively controlled by changing the lengths of members, making it attractive as a platform for adaptive bionic and locomotive robots. In this paper, the regular 30-strut tensegrity is used as the skeleton of a locomotive robot. The robot is flexible and highly redundant, making it adaptive to unconstrained environments and ideal for various co-robotic scenarios such as space exploration, emergency rescue, and so on. Compared with the 6-strut tensegrity robot, the 30-strut tensegrity robot with more controllable degrees of freedom possesses more various motion behaviors as well as gait primitives. To demonstrate the effectiveness of the motion behaviors of the 30-strut locomotive robot, we analyze the diverse collection of behaviors generated by actively changing the lengths of struts. It is found that rolling motion is robust and easy to be actuated, and multi-gait and individual-gait of rolling motion are observed. However, its high dimensionality and strong dynamic nature complicate the motion control. A physical prototype is manufactured to verify the found motion behaviors. The results show the potential uses of 30-strut tensegrity as multifunctional locomotive robots.