Cheetah‐Inspired Tensegrity Quadruped Robot for High‐Speed Galloping and Terrain Adaptation

Tensegrity structures, which combine rigidity and flexibility, can overcome the limitations of rigid robots in challenging terrains and the slow locomotion speed of soft robots. Their structural characteristics and mechanical properties are akin to musculoskeletal systems, offering valuable insights for the development of bioinspired robots. In this study, we present a galloping quadruped robot equipped with an innovative flexible tensegrity spine. The tensegrity spine successfully mimics the energy conversion mechanism of a natural spine. The elastic cables within the tensegrity spine store and release elastic potential energy during spinal flexion and extension. The released energy provides propulsion, enabling the robot to achieve higher speeds and leap over obstacles of a certain height. Additionally, the lateral bending and axial rotation of the spine enhance the robot's stability and maneuverability. We developed a Lagrangian dynamics model of the tensegrity spine, and dynamic analysis shows that cable stiffness directly regulates spinal morphology, energy efficiency, turning angle, and rotation angle. Additionally, rigid legs with unidirectional ratchet wheels are designed to replicate the mechanism of alternating ground contact between the front and hind legs. Extensive experiments show that the robot can gallop at a speed of 1.87 body lengths per second with optimized cable stiffness in the tensegrity spine, effectively navigate challenging terrains (such as grass, gravel roads, and steps), and successfully clear obstacles up to 0.5 body heights (100 mm) with its forelegs, while climbing slopes of up to 17.4°.