Optimal design of hand-carrying rocker-bogie mechanism for stair climbing

Transporting heavy packages while climbing stairs can be a very difficult or dangerous task. In situations where this task is frequently required such as construction sites, workers would use equipment such as a back rack for convenience, but still it becomes a difficult task as the weight increases. In this paper, we propose a stair climbing hand-carrying cart based on the rocker-bogie mechanism. We conduct an optimal design of the kinematic variables of the rocker-bogie mechanism for stable stair climbing using Taguchi methodology. Fluctuations and a tilted angle during stair climbing are considered to formulate the objective function. Three different shapes of typical stairs are selected as user conditions to determine a robust optimal solution. The results are verified by experiments using a testing set-up of three stair profiles, and the experimental results are compared with simulation. We expect that the results of this research can be applied to stair climbing robot design.