Omnidirectional Mobile Robots in Rough Terrain

Mobile robots are finding increasing use in military, disaster recovery, and exploration applications. These applications frequently require operation in rough, unstructured terrain. Currently, most mobile robots designed for these applications are tracked or Ackermann-steered wheeled vehicles. Methods for controlling these types of robots in both smooth and rough terrain have been well studied. While these robots types can perform well in many scenarios, navigation in cluttered, rocky, or obstacle-dense urban environments can be difficult or impossible. This is partly due to the fact that traditional tracked and wheeled robots must reorient to perform some maneuvers, such as lateral displacement. Omnidirectional mobile robots could potentially navigate faster and more reliably through cluttered urban environments and over rough terrain, due to their ability to track near-arbitrary motion profiles. Currently, the drive mechanisms of most omnidirectional mobile robots are designed to perform well in indoor and benign environments.

This project focuses on the analysis, design, and control of omnidirectional mobile robots for use in rough terrain. The robots in this study use active split offset caster drive mechanisms that allow high thrust efficiency during omnidirectional motion and low ground pressures over rough terrain. The design guidelines developed in this research are scalable and applicable for a class of omnidirectional mobile robots.

MIT is collaborating with the Illinois Institute of Technology in constructing a prototype robot to experimentally validate the effectiveness of the design guidelines and controller.

This work has been funded by the U.S. Army Research Office.