Stair-Climbing Robots: A Review on Mechanism, Sensing, and Performance Evaluation

Indoor service robots have been widely introduced in the fields of cleaning, delivery, education, guidance, and healthcare, etc. in indoor environments. The mobility of an indoor service robot is essential to expanding its applications. However, the mobility of existing indoor service robots is highly limited by surrounding indoor environments. For example, a stair is one of the major obstacles that restrict the reachable areas of indoor service robots. Even though many studies have been performed to develop reliable and fast stair-climbing robots based on legged, tracked, wheel-legged and wheel-linkage mechanisms, a market-dominant stair-climbing robot remains unsolved. This review investigates the efforts of engineers devoted to stair-climbing robots. To this end, the locomotion mechanisms of stair climbing robots are classified and their sensing method are summarized. In this review, we also propose useful criteria for evaluating the stair-climbing ability of an indoor service robot. By virtue of these criteria, the stair-climbing performance of existing robots are qualitatively compared. We hope this review helps develop the reliable and fast stair-climbing robots and the reasonable criteria for their performances.

Automated summary

Indoor service robots are widely used in various indoor environments for cleaning, delivery, education, guidance, and healthcare. However, the mobility of these robots is limited by obstacles like stairs. Despite many studies, a market-dominant stair-climbing robot has not yet been developed. This review examines the efforts made by engineers in this field, categorizes the locomotion mechanisms and sensing methods of stair-climbing robots, and proposes criteria for evaluating their performance.