Experimental Characterization of a Robotic Inflatable Wheel

Inflatable wheels are a promising concept for longrange exploration of Mars as well as extremely rugged terrestrial terrains. This paper describes experimental studies that characterize the mobility of a single robotic inflatable wheel in terms of its ability to negotiate Mars-like cohesion-less soils, climb large discrete obstacles and endure the wear and tear caused by driving over kilometers of abrasive rocks. These studies were performed with a testbed apparatus that allowed variation of tire design, wheel loading, speed / acceleration profiles, tire pressure and traverse length. An in-line brushless motor controlled by a PID velocity control loop drives the wheel. This paper summarizes the most significant experimental results and discusses the impact of those results on aspects of robotic vehicles with inflatable wheels, such as state estimation and motion control.