A new Bioinspired-inspired robot that flies, rolls, walks, and more

The newly created Realistic Transformers are able to reshape their body to achieve eight different types of movement and can independently assess the environment they encounter to choose the most effective combination of movements for maneuvering.

Dubbed the M4 (for Multi-Modal Mobility Morphobot), the new robot can roll on four wheels, turn its wheels into rotors and fly, stand on two wheels like a meerkat to look over obstacles, and “walk” with its wheels like feet, use two spinners to help it Roll over steep slopes on two wheels, tumble, and more.

says Morey Strange (PhD ’83), Hans W. Professor, director of the California Institute of Technology Center for Independent Systems and Technologies (CAST), where the robot was developed.

M4 is the brainchild of Gharib and Alireza Ramzani, associate professor of electrical and computer engineering at Northeastern University. The team supporting the technical aspects of M4 consists of Eric Sihite, a postdoctoral research associate in space at Caltech. Reza Nimovi, design engineer at CAST; and Arash Kalantari of the Jet Propulsion Laboratory, which is managed by the California Institute of Technology for NASA. A paper announcing the new robot has been published in Nature Communications On June 27th.

says Ramzani, author of Nature Communications paper.

The robot’s flexibility in movement, combined with artificial intelligence, allows it to choose the form of movement that will be most effective based on the terrain in front of it. Imagine the M4 exploring an unfamiliar environment: It might start rolling on four wheels, which is its most energy-efficient mode. Upon reaching an obstacle such as a boulder, it can mount on two wheels to look over it to get a clearer picture of the land in front of it. Then, if it sees a valley or other feature that the wheeled robot can’t traverse, it can reconfigure its wheels into roundabouts, fly over the valley to the other side, and resume rolling.

says Gharib, co-author of the book Nature Communications paper.

One of the main advantages of the M4 is its ability to reuse its attachments for wheels, legs or impellers. When the M4 needs to stand on two wheels, two of its four wheels fold up and the internal propellers rotate upwards, providing balance for the robot. When the M4 needs to fly, all four wheels fold up, and the thrusters lift the robot off the ground.

The links on the wheel assemblies allow the M4 to perform a walking motion. In the current iteration of the M4, the walking motion is mostly proof of concept. However, with the foreseen developments, future M4 generations could have the ability to walk effectively across the broken terrain that a wheeled robot would encounter.

The M4 robot converts from driving mode to walking mode.

Credit: California Institute of Technology

The design of the M4 was heavily influenced by nature: Gharib and colleagues were inspired by how chukars (a type of partridge) use flap of their wings to give them leverage while running up steep inclines, for example, and how sea lions use their flippers for different types of locomotion at sea and on land. Although biologists have previously cited such examples of repurposing the animal kingdom, the concepts they illustrate are now being explored in the field of engineering.

The M4 is equipped with autonomous capabilities and can make decisions on its own about how best to navigate through a complex environment. The robot has also been tested outdoors and has toured the California Institute of Technology campus terrain.

the Nature Communications Paper titled “Multi-Modal Mobility Morphobot (M4), a Platform for Purpose Reconfiguration Screening for Improved Mobility Morphobot.” This research was funded by JPL and the National Science Foundation.