摘要Inspired by the morphology characteristics and the locomotion mechanisms of the earthworm,and the snakes'morphology characteristics and motivated by the demands for multi-modal locomotion robots in variable working environments,this paper presents a novel bi-modal robot named as Snake-Worm Locomotion Robot(SWL-Robot).Two fundamentally different locomotion mechanisms,the earthworm's peristaltic rectilinear locomotion and the snake's lateral undulation,are synthe-sized in the SWL-Robot design.In detail,the SWL-Robot consists of six earthworm-like body segments interconnected by rotational joints and a head segment equipped with a couple of independently driven wheels.By actuating the segments following a peristaltic wave-like gait,the robot as a whole could perform earthworm-like rectilinear crawling.The robot could also perform snake-like undulatory locomotion driven by differential motions of the wheels at the head segment.To understand the relationship between the design parameters and the robotic locomotion performance,kinematic models of the SWL-Robot corresponding to the two locomotion modes are developed.Rich locomotion behaviors of the SWL-Robot are achieved,including the peristaltic locomotion inside a tube,multiple planar motions on a flat surface,and a hybrid motion that switches between the tube and the flat surface.It shows that the measured trajectories of the SWL-Robot agree well with the theoretical predictions.The SWL-Robot is promising to be implemented in tasks where both tubular and flat environments may be encountered.