Rolling Motion of Bar-Driven Soft Spherical Tensegrity Robot Based on Dodecahedron

Soft spherical tensegrity robots exhibit many desirable properties, including impact resistance and extreme lightweight, which give them strong potential for operation in complex environments such as search and rescue missions and space exploration. However, existing spherical tensegrity robots are still unable to achieve 100% exploration in unknown and complex terrains. In this study, we present a 10-bar soft spherical tensegrity robot based on dodecahedron tensegrity (TR-10) with multiple movement gaits. It can generate a rolling motion by actively changing the length of the internal drive module, and the MATLAB dynamic model is established for simulation. The multi-objective optimization method is used to obtain the driving strategies for various basic gaits of the TR-10. The generated movement paths, formed by combining gaits, can fully cover the map. At the same time, the method for determining the rolling axis is proposed, which can enable the robot to roll to the target point along the optimal path. Finally, we fabricated the TR-10 prototype capable of a wireless-controlled rolling motion. By comparing the simulation and experimental results of the basic gaits and movement paths, the effectiveness of the proposed method is verified. In addition, we also compare it with the classical 6-bar 24-cable tensegrity robot, and the results show that our proposed TR-10 can complete different paths with shorter distances and smaller offsets.