Rattlesnakes inspire search-and-rescue robot design

Rattlesnakes have provided the inspiration for the movements of a robot designed for entering dangerous environments.

Researchers at Carnegie Mellon University (CMU) and the Georgia Institute of Technology in the US studied sidewinder snakes to work out how to make their robot take rapid and sharp turns as it moved.

“We’ve been programming snake robots for years and have figured out how to get these robots to crawl amidst rubble and through or around pipes,” said Prof Howie Choset from CMU’s Robotics Institute.

“By learning from real sidewinders, however, we can make these manoeuvres much more efficient and simplify user control. This makes our modular robots much more valuable as tools for urban search-and-rescue tasks, power plant inspections and even archaeological exploration.”

Snakes have become a popular model for robot builders and investigations are underway into how robotic reptiles might be used for dangerous and difficult tasks from decommissioning nuclear power stations to exploring Mars.

The new research, published this week in the Proceedings of the National Academy of Sciences Early Edition, showed how the complex motion of a sidewinder can be described in terms of two wave motions — vertical and horizontal body waves — and how changing the phase and amplitude of the waves enables snakes to achieve exceptional manoeuvrability.

By measuring the movements of living snakes at Zoo Atlanta, the researchers observed that sidewinders make gradual changes in direction by altering the horizontal wave while keeping the vertical wave constant. They also discovered that making a large phase shift in the vertical wave enabled the snake to make a sharp turn in the opposite direction.

Applying these controls to the robot allowed the robot to replicate the turns of the snake, while also simplifying control.

“By looking for insights in nature, we were able to dramatically improve the control and maneuverability of the robot while at the same time using the robot as a tool to test the theorized control mechanisms of biological sidewinders,” said Henry Astley of Georgia Tech, who led the observations.

This research was supported by the National Science Foundation, the Army Research Office, the Georgia Tech School of Biology and the Elizabeth Smithgall Watts Endowment.