M4: The Multi-Modal Mobility Morphobot That Can Do It All

Friday - June 30 2023, 04:48 UTC - 1 year ago

The M4 robot is a new autonomous robot designed by researchers at Caltech's Center for Autonomous Systems and Technologies (CAST). It can roll on four wheels, turn its wheels into rotors and fly, stand on two wheels to see over obstacles, use its wheels like feet to walk, use two rotors to add momentum while it rolls up inclines on two wheels, tumble, and more. It's AI enables it to autonomously decide which form of motion to use for navigating its environment, and it could be useful for search and rescue or exploration missions. The research was funded by NASA’s Jet Propulsion Laboratory and the National Science Foundation.

Robots are slowly getting smarter, mostly thanks to advances in artificial intelligence that enable them to learn on their own rather than requiring constant human guidance. But despite being able to independently learn new tasks, most robots are still limited to a single form of motion—that is, they either walk, crawl, swim, fly, or move within a given area. A new robot designed by researchers at Caltech’s Center for Autonomous Systems and Technologies (CAST) can do it all, though.

Called M4, which is short for Multi-Modal Mobility Morphobot, the robot can roll on four wheels, turn its wheels into rotors and fly, stand on two wheels to see over obstacles, use its wheels like feet to walk, use two rotors to add momentum while it rolls up inclines on two wheels, tumble, and more. In a paper published this week in Nature Communications, the robot’s creators explain that their inspiration came from various animals.

Chukars, a type of partridge found in the western US, can run uphill with the help of their wings, flapping them to create momentum and make the climb easier. Meerkats can walk on all fours or rise up on their two hind legs to get a better view of whatever’s in front of them. Sea lions can use their flippers to move in different ways in water and on land. And so on.

M4 looks like a sort of flat, rectangular car with four large wheels. Except each of the wheels has a propeller in it, and they can double as legs or thrusters. If the bot wants to stand on two wheels, the other two fold up and their propellers start spinning to add balance. If the bot wants to fly, all four of the wheels fold up and the propellers lift the robot off the ground, like a drone. The wheel assemblies are also equipped with joints that enable the bot to walk, though its creators say this capability needs to be further refined.

"Our aim was to push the boundaries of robot locomotion by designing a system that showcases extraordinary mobility capabilities with a wide range of distinct locomotion modes. The M4 project successfully achieved these objectives," Alireza Ramezani, a corresponding author of the paper, said in a press release.

Using AI, the M4 robot can perceive its environment and decide which form of motion to employ for navigating it—then, like the Transformers you may have seen in cartoons as a kid (or in the movie released earlier this month), M4 morphs into whatever shape needed to move forward. For example, it could go from rolling across a flat surface on its four wheels to pausing and standing on its rear wheels to see over an obstacle. If that obstacle revealed water or another terrain it couldn’t cross on wheels, it could switch its wheels into rotor mode and fly.

There are already search and rescue robots that aim to search disaster sites to help find and recover people or objects. M4 could serve a similar role, with its ability to navigate complex terrain coming in especially handy. Its creators say it could even be used to explore other planets, like a Mars rover with even more abilities. The research was funded by NASA’s Jet Propulsion Laboratory and the National Science Foundation, so both instiutitions will likely keep an eye on the project as it develops.