Using Manipulation to Enable Adaptive Ground Mobility

In order to accomplish various missions, autonomous ground vehicles must operate on a wide range of terrain. While many systems such as wheels and whegs can navigate some types of terrain, none are optimal across all. This creates a need for physical adaptation. This paper presents a broad new approach to physical adaptation that relies on manipulation. Specifically, we explore how multipurpose manipulators can enable ground vehicles to dramatically modify their propulsion system in order to optimize performance across various terrain. While this approach is general and widely applicable, this work focuses on physically switching between wheels and legs. We outline the design of "swappable propulsors" that combine the powerful adhesion forces of permanent magnets with geometric features for easy detachment. We provide analysis on how the swappable propulsors can be manipulated, and use these results to create a functional prototype robot. This robot can use its manipulator to change between wheeled and legged locomotion. Our experimental results illustrate how this approach can enhance energy efficiency and versatility.