A Variable Footprint Mobile Robot With Novel Transformable Chassis

This article proposes a novel four‐wheeled mobile robot with footprint reconfiguration capability. A variable footprint mobile robot is a type of robot that can reconfigure (reduce or expand) its footprint according to the dimensional constraints of the environment. In the proposed mobile robot, footprint reconfiguration is made possible through a novel transformable chassis based on a modified version of Hart’s A‐frame and a slider‐crank type actuation mechanism. Theoretically, the proposed transformable chassis can grant footprint reductions up to 51%. The mobile robot comprises four main modules: transformable chassis, actuation mechanism, suspension system to reduce ground‐induced vibrations, and wheel drive system to facilitate locomotion. This modular design promotes customizability, enabling creation of different embodiments. The developed prototype of the mobile robot demonstrated a maximum footprint reduction of 40.7%. During the implementation, it demonstrated semi‐autonomous navigation using a combination of a simultaneous localization and mapping (SLAM) algorithm, a dynamic window approach (DWA) local planner, and a Dijkstra’s algorithm‐based global planner, navigating through an arena while utilizing its footprint variation capability to travel through narrow regions.