A Tiltable Head Could Improve Robot Navigation of Disaster Debris

Researchers at the Georgia Institute of Technology built a robot that can penetrate and 'swim' through granular material. In a new study, they show that varying the shape or adjusting the inclination of the robot's head affects the robot's movement in complex environments.

Transcript

00:00:00 here at Georgia Tech in the complex rology and biomechanics lab we look at an organism a sandfish that swims into a granular medium sand we look at a physical model of that organism a robot that can have a head that can tilt up and down to make it swim up or down in the sand as well and we look at physics models drag of objects within the granular media to try to understand the

00:00:24 forces that such motion generates in the material one of the challenges for uh robots that must operate in complex shifting environments like those found in landslides or other disaster sites is that we don't have deep understanding of the principles by which uh matter interacts with such environments one source of inspiration is organisms like the little sandfish lizard that can in

00:00:49 fact swim and maneuver quite readily in a complex terrain biologists have have argued and speculated that the head shape of this animal allows the animal to move in the sand well and the predominant idea is that the uh head is basically a kind of a wedge shape which reduces drag as the animal moves through the medium so our robot is based on the principles we've discovered in the

00:01:15 sandfish lizard we took square blocks of wood and cut little wedges into those square blocks and we could vary the angle of that wedge and we could study the effect of the uh head on the robot the first thing we did uh was we took the shapes the candidate shapes and we placed them on our robot arm and towed them through the granular media and measured the forces we measured drag

00:01:36 forces and lift forces and sure enough the more streamlined looking shapes had smaller drag forces on them like we expect the thing that surprised us was the magnitude of the change in lift forces we were able to vary lift forces by nearly a factor of 10 by varying from most streamline to blunt shape these results point to interesting directions in future biological studies as well as

00:02:03 future robotic studies on the biological end we now have a hypothesis that in fact head shape in these organisms can be used not only to reduce drag but to generate lift forces and so we expect that organisms could evolve uh heads which have particular shapes to best allow them to maneuver in different kinds of materials on the robotics end we think that an understanding of

00:02:27 control surfaces that devices can use to maneuver within loose unstable material uh will allow them not just to move forward but to move up and down within material and we think that by understanding the principles by which the organisms move in this terrain and then designing physical models which incorporate these principles we can learn the basic uh foundations of how

00:02:51 this motion occurs and uh help inform our robotics collaborators on how to design better devices