Foldable front legs based shape-changing crawler capable of constant pose locomotion over rugged terrain

This paper presents practical design and hardware implementation issues of an adaptable crawler mechanism for a mobile robot, enabling it to maintaining its constant desired pose when roving. For this purpose, a novel multi-legged adaptable crawler (MLAC) prototype is proposed by utilizing a spring and a rack-and-pinion unit. More specifically, the MLAC prototype allows changing of the crawler configuration in order to adapt to a local surface topology. When the MLAC prototype is mounted under the mobile robot, even though the robot might encounter ascending/descending slopes and thresholds, the mechanism allows it to preserve its locomotive pose continuously. The design and performance of the MLAC prototype is explained in detail, and its effectiveness is verified through experiments in our laboratory environments.