Design of an Impact-resistant Elbow Mechanism for Wheel-legged Robot Crawling

Wheel-legged robots utilize their arms for efficient crawling in low and narrow passages. However, during the transition from standing to crawling motion mode, wheeled-legged robots, which are underactuated systems, are susceptible to falling and potential damage. Additionally, the elbow joint requires a high torque during robot crawling. Therefore, we designed an elbow mechanism driven by a linear actuator for BIT- W robot. The torque requirement of the elbow joint is analyzed by constructing a crawling model of the robot. Subsequently, a novel optimization method is proposed to enhance impact resistance by optimizing the mechanical parameters. Finally, The experiments conducted validate the elbow mechanism's capability to provide stable support for crawling and motion mode switching. Moreover, the impact mitigation factor (IMF) results substantiate the mechanism's effective enhancement of the arm's impact-resistant ability.