Abstract: Tensegrity structures, embodying the principles of continuous tensioning and discrete compression, have emerged as fundamental frameworks in locomotive soft robotics for navigating uneven and unpredictable environments, owing to their flexible and resilient traits. By means of a straightforward and cost-effective method to achieve structure-driven, vibration-driven tensegrity shows great potential, particularly in tasks demanding random exploration. However, the design guidance for vibration-driven tensegrity and their performance evaluation in unstructured terrain remain unrevealed due to the complex dynamics of the structure. This paper presents a small six-bar tensegrity robot, driven by wireless vibration motors, designed for deployment in disaster rescue and search scenarios. Finite element simulation is used to investigate how structural characteristics, excitation parameters, and the arrangement of motors affect the kinematic performance of this tensegrity system. A prototype of the six-bar tensegrity robot with three motors located on the lower ends of the three lower struts is designed and manufactured after the numerical simulations. A simple control policy which adjusts the motion of the tensegrity robot by turning on or off the motors on different locations is proposed. The prototype with and without the control policy is tested in man-made environments of various complexity. It shows that the ability and efficiency of the tensegrity robot in exploring unstructured environments is significantly enhanced by the proposed control policy. It is believed that the potential of the vibration-driven tensegrity robot could be further exploited by integrating multi-source sensors and more intelligent control policies.

Key words: Finite element simulation')">Finite element simulation, Parametric design, Tensegrity, Unstructured environment, Vibration