Never-Before-Seen Robotic Locomotion Discovered Inspired by Centipedes

Monday - May 8 2023, 14:11 UTC - 1 year ago

Georgia Institute of Technology scientists, inspired by centipedes, have developed a unique theory of multilegged locomotion that uses leg redundancy to move robustly over challenging surfaces. Experiments showing the scalability of the concept have been conducted and the results are highly promising for a wide range of applications, from search and rescue to robots deployed on Mars and for other rugged terrains.

A team of physicists, engineers, and mathematicians at the Georgia Institute of Technology are mimicking centipedes’ movements to develop a new theory of multilegged locomotion. Through their experiments, they discovered that robots with more legs could move across uneven surfaces with agility without any additional sensing or control technology.

This is according to a press release by the institution published on Friday.

"When you see a scurrying centipede, you're basically seeing an animal that inhabits a world that is very different than our world of movement," said Daniel Goldman, the Dunn Family Professor in the School of Physics. "Our movement is largely dominated by inertia. If I swing my leg, I land on my foot, and I move forward. But in the world of centipedes, if they stop wiggling their body parts and limbs, they basically stop moving instantly." .

The team of researchers developed a theory that proposes that adding leg pairs to the robot increases its ability to move robustly over challenging surfaces — a concept they call spatial redundancy. This results in robot legs that are successful on their own without the need for sensors to interpret the environment. If one leg fails, the rest keeps it moving regardless.

--- Search and rescue and more --- .

"With an advanced bipedal robot, many sensors are typically required to control it in real-time," said Baxi Chong, a physics postdoctoral researcher. "But in applications such as search and rescue, exploring Mars, or even micro-robots, there is a need to drive a robot with limited sensing. There are many reasons for such sensor-free initiative. The sensors can be expensive and fragile, or the environments can change so fast that it doesn’t allow enough sensor-controller response time." .

To test the theory, the researchers built a wildly uneven terrain and had robots navigate it, increasing their number of legs by two each time, starting with six and eventually expanding to 16. The scientists found that as the leg count increased, the robot could more agilely move across the terrain, even without sensors.

"It's truly impressive to witness the multilegged robot's proficiency in navigating both lab-based terrains and outdoor environments," said in the statement Juntao He, a Ph.D. student in robotics. "While bipedal and quadrupedal robots heavily rely on sensors to traverse complex terrain, our multilegged robot utilizes leg redundancy and can accomplish similar tasks with open-loop control." .

The study was published in Proceedings of the National Academy of Sciences in March.

The study demonstrated the gain of using spatial redundancy to traverse tough terrain and surfaces over traditional robot systems. This concept, especially useful for search and rescue robots and Mars rovers, can help robots overcome obstacles or changes in the terrain without the need for sensors. Additionally, it can lower the cost of the robot, improving its usability for many other applications. The team has also designed a 3D printed 56-legged robot called Omnipod which leverages this new concept. This robot can ascend steps, run across a carpet and traverse rough surfaces without any visual or tactile sensing. In addition, they've also engineered the N-Pod platform, which can alter its own body or gait shape to accommodate different terrain or goals.