Search and rescueTiltable-head robots adept at navigating disaster debris
Search and rescue missions have made the headlines in the last eighteen months, following the earthquakes in Haiti and Chile, the floods in Pakistan and New Zealand, and the tsunami in Japan; machines able to navigate through complex dirt and rubble environments could have helped rescuers after these natural disasters, but building such machines is challenging; Georgia Tech researchers have now built a robot that can penetrate and “swim” through granular material
Tiltable head improves navigation for undulating robots // Source: robots.org
Search and rescue missions have made the headlines in the last eighteen months, following the earthquakes in Haiti and Chile, the floods in Pakistan and New Zealand, and the tsunami in Japan. Machines able to navigate through complex dirt and rubble environments could have helped rescuers after these natural disasters, but building such machines is challenging. Researchers at the Georgia Institute of Technology recently built a robot that can penetrate and “swim” through granular material. In a new study, the researchers show that varying the shape or adjusting the inclination of the robot’s head affects the robot’s movement in complex environments.
“We discovered that by changing the shape of the sand-swimming robot’s head or by tilting its head up and down slightly, we could control the robot’s vertical motion as it swam forward within a granular medium,” said Daniel Goldman, an assistant professor in the Georgia Tech School of Physics.
Results of the study were presented on 10 May at the 2011 IEEE International Conference on Robotics and Automation in Shanghai. Funding for this research was provided by the Burroughs Wellcome Fund, National Science Foundation, and the U.S. Army Research Laboratory.
A Georgia Tech release reports that the study was conducted by Goldman, bioengineering doctoral graduate Ryan Maladen, physics graduate student Yang Ding, and physics undergraduate student Andrew Masse, all from Georgia Tech, and Northwestern University mechanical engineering adjunct professor Paul Umbanhowar.
“The biological inspiration for our sand-swimming robot is the sandfish lizard, which inhabits the Sahara desert in Africa and rapidly buries into and swims within sand,” explained Goldman. “We were intrigued by the sandfish lizard’s wedge-shaped head that forms an angle of 140 degrees with the horizontal plane, and we thought its head might be responsible for or be contributing to the animal’s ability to maneuver in complex environments.”
For their experiments, the researchers attached a wedge-shaped block of wood to the head of their robot, which was built with seven connected segments, powered by servo motors, packed in a latex sock and wrapped in a spandex swimsuit. The doorstop-shaped head — which resembled the sandfish’s head — had a fixed lower length of approximately four inches, height of two inches and a tapered snout. The researchers examined whether the robot’s vertical motion could be controlled simply by varying the inclination of the robot’s head.
Before each experimental run in a test chamber filled with quarter-inch-diameter plastic spheres, the researchers submerged
