A Reconfigurable Rocker-Bogie Robot for High Step Climbing and Turning

2026-07-01

AI Summary

This study addresses the inherent trade-off in conventional rocker-bogie robots between high-step climbing capability and efficient in-place turning. The authors propose a reconfigurable rocker-bogie mechanism that integrates actuated joints to actively control limb articulation, enabling seamless switching between four-wheel and six-wheel configurations. Combined with a rear omnidirectional differential drive, this design achieves zero-radius steering and enhanced obstacle negotiation using only a minimal number of actuators. Experimental results demonstrate that the prototype attains over five times faster zero-radius turning speeds compared to traditional designs, reduces average required wheel torque to 17% of conventional levels, and successfully surmounts 40-cm-high steps in an average of 6.4 seconds, significantly improving both mobility and energy efficiency.

Abstract

This study proposes a reconfigurable rocker-bogie mechanism that achieves efficient turning motion with a small number of actuators while maintaining high step-climbing capability. By installing motors at the bogie joints and actively swinging up and down bogies, the system enables switching between four-wheel and six-wheel configurations. Omnidirectional wheels are mounted on the rear ends of the rockers, allowing smooth turning in the four-wheel configuration based on a differential-drive model. Experimental evaluation using a prototype robot demonstrated that the proposed mechanism achieves zero-radius turning at a speed more than five times that of a conventional rocker-bogie mechanism equipped with six non-steerable grip wheels, while requiring only approximately 17% of the total average wheel torque. In addition, the robot successfully climbed a 40 cm step with an average climbing time of 6.4 s, confirming its high turning and step-climbing performance.

Problem

• rocker-bogie
• high step climbing
• zero-radius turning
• reconfigurable mechanism
• mobile robot

Innovation

• reconfigurable rocker-bogie
• zero-radius turning
• omnidirectional wheels
• step-climbing capability
• actuated bogie joints