Robots with legs and robots with wheels are two completely different worlds. When it comes to robot locomotion methods, wheels are suitable for some things, while legs are better for others.
Now, a team of researchers from Texas A&M University has announced the creation of an adaptable Wheel-and-Leg Transformable Robot (α-WaLTR) that can traverse over varying surfaces, including staircases, more efficiently. The α-WaLTR will move with wheels or legs depending on their immediate need and will be able to decide for itself which to use. The choice will be determined by the onboard sensors and imaging system.
The development was carried out as part of the DARPA OFFensive Swarm-Enabled Tactics (OFFSET) Sprint-5 program to develop unmanned ground vehicles with agile and versatile locomotive capabilities for urban military operations.
The idea behind the development is to create robots of a new type, in which the same structural elements can be used for different applications. In particular, in this project, the researchers managed to come up with a new design of wheels that allow not only to move on a relatively flat surface but also to transform into a new design for movement on difficult sections of the path.
When traveling over relatively flat terrain, the α-WaLTR robot rolls quickly and efficiently on four rubber tread wheels. However, as soon as the robot encounters obstacles such as stairs, rocks, the gear system in the center of each wheel causes its wheels to open into three claw-shaped sections. After that, each of these claws rotates forward. The entire structure will cling to uneven ground, pulling the α-WaLTR up and over it.
“Legged locomotion is more versatile, but suffers from inherent structural, mechanical and control complexities,” said Kiju Lee, associate professor in the Department of Engineering Technology and Industrial Distribution. “The proposed testbed will be equipped with novel wheel/leg transformable mechanisms, which can switch between the two locomotion modes actively adapting to its environment, but without needing any additional actuator.”
The team is rapidly developing prototypes and will showcase this new hardware platform at the OFFSET FX5 tentatively scheduled for February 2021. Despite the fact that the project is being developed for military use, the team hopes this technology will transcend the field.
“While the current focus is on defense and other military applications, these types of adaptable mobile robots can be applied to many other areas, such as space, domestic service, surveillance, and agriculture,” Lee said.