An adaptive step-climbing method for a RHex-style robot

A RHex-style hexapod robot is a type of legged robot which can perform lots of moving gaits for different applications, due to its simple structure and strong mobility. However, traversing over the high obstacles has always been a big challenge for legged robots. In this paper, an adaptive posture adjustment method is proposed for robot climbing steps at different heights, which even enables the robot to climb the step with two times of leg length. First, the existing step-climbing gaits are discussed, it is found that these gaits are not universal in RHex robots of different sizes. Then, three different methods to drag rear legs close to the step for adjusting body inclination are performed when placing front legs on top of the step, which enables RHex with different sizes to perform the rising stage of climbing gait. The simulation analysis of step climbing is utilized to verify the feasibility of the proposed gait. Finally, the step-climbing experiments at different heights are performed, and the results show the superiority of the proposed gait due to climbing higher steps and a 100% success rate.