A locomotive strategy for a stair-climbing mobile platform based on a new contact angle estimation

This paper presents a locomotive strategy for a stair-climbing mobile platform built on a rocker-bogie platform, which can surmount indoor stairs or steps by virtue of a new contact angle estimation method. First, link parameters of the rocker-bogie mechanism are optimized through the Taguchi method, with the aim of making the trajectory of the center of mass (CM) of the mobile platform as smooth as possible. Based on the optimization result, the mobile platform is compactly designed to suit indoor applications. A simple, robust and cost-effective estimation method is then proposed to obtain information of the contact angle between each wheel and the stairs with high fidelity. A composite locomotion strategy is suggested, based on the kinematic and kinetic analysis, combined with the contact angle estimation. The stair-climbing capability of the proposed mobile platform is successfully validated through extensive experiments.