The newly created transformer robot is able to change the configuration of its body to achieve different types of movement and can autonomously assess the environment to choose the most effective combination for maneuvering.

The new robot, dubbed the M4 (Multi-Modal Mobility Morphobot), can roll on four wheels, fly, stand on two wheels, "walk" using its wheels as legs, and use two rotors to overcome steep slopes on two wheels.

According to Professor Maury Gharib, director of the Center for Autonomous Systems and Technologies (CAST) at the California Institute of Technology (Caltech), a robot with such a wide range of capabilities would find wide application - from transporting injured people to the hospital to exploring other planets.

M4 was developed by Gharib and Alireza Ramezani, Associate Professor of the Department of Electrical and Computer Engineering at Northeastern University. The team supporting the technical aspects of the M4 included Eric Sihite, a postdoctoral researcher in aerospace at Caltech, Reza Nemovi, a design engineer at CAST, and Arash Kalantari from JPL.

"Our goal was to expand the boundaries of robot locomotion by developing a system that demonstrates exceptional mobility capabilities with a wide range of different locomotion modes. The M4 project has successfully achieved these goals," says Ramezani.

The flexibility of the robot's movements combined with AI allows it to choose which form of locomotion will be most effective depending on the terrain in front of it. The institute's press release says that the M4 exploring an unfamiliar environment can start moving on four wheels, which is its most energy-efficient mode. After reaching an obstacle, such as a boulder, he can stand on two wheels to inspect it and get a clearer picture of the terrain ahead. Then, if he sees a ravine or other obstacle that the wheeled robot cannot overcome, he can reconfigure his wheels to flight mode, fly over the ravine to the other side and continue driving.

"When faced with an unknown environment, only those robots that are able to repurpose their multimodal components with AI can achieve success," says Gharib.

When the M4 needs to stand on two wheels, two of the four wheels fold up and their built-in propellers rotate, ensuring the robot's balance. When the M4 needs to fly, all four wheels fold up and the propellers lift the robot off the ground.

The hinges on the wheel nodes allow the M4 to make walking movements, but it is noted that the current iteration of walking is more of a proof of concept. However, with the expected progress, future generations of the M4 will be able to move more efficiently over rough terrain.

The robot was tested outdoors and navigated the terrain on the Caltech campus. The article "Multi-Modal Mobility Morphobot (M4), A Platform to Inspect Appendage Repurposing for Locomotion Plasticity Enhancement" was published in Nature Communications.