Crawling Soft Robot Exploiting Wheel-Legs and Multimodal Locomotion for High Terrestrial Maneuverability

How to efficiently traverse complex terrain remains an unresolved challenge for mobile soft robots, because their deformable bodies limit the magnitude of the forces they can exert on the environment. To achieve high maneuverability, this article demonstrates a pneumatic soft crawling robot equipped with wheel-legs capable of multimodal locomotion to negotiate various obstacles. The soft robot consists of a pneumatic soft actuator capable of multiple modes of bending deformation as the body and four identical multispoked wheel-legs with passive unidirectional forward rotation as limbs. The synergy of the body actuator and wheel-legs enables the robot to achieve multiple crawling gaits, including gecko-like crawling and inchworm-like crawling. A single gait or a combination of multiple gaits, as well as shape-morphing of the body, enables the robot to navigate obstacles as diverse as confined spaces, inclined surfaces, gaps, and stairs, or to avoid obstacles by circumventing them. Our study substantially improves the maneuverability of pneumatic soft crawling robots, thereby providing new routes for the potential applications of soft robots in obstacle-filled scenarios, including search and rescue, exploration, and inspection.