Scientists at the Georgia Institute of Technology have developed a robot that can enter and navigate through granular medium. A new research was conducted to prove that it is possible to control a robot's motion in tough situations either by changing the inclination of the robot’s head or by altering the shape.
Robot with Wedge-shaped Head
The results of the research were displayed at the 2011 IEEE International Conference on Robotics and Automation. This research project received financial support from the Burroughs Wellcome Fund.
Researchers connected a block of wood, in the form of a wedge, to the head of the robot, which resembled the sandfish's head. They studied whether the vertical motion of robots could be manipulated by changing the inclination. The test chamber was filled with plastic spheres of quarter-inch diameter. Before beginning the experiment, researchers placed the robot a few inches into the granular medium and leveled the surface. The robot’s position was tracked continuously till it reached the surface of the container.
The robot was positioned at five different inclination angles and researchers evaluated the vertical movement of the robot. They discovered that when the robot’s head formed an angle of 155° with the horizontal surface, the robot traveled in a downward direction as a result of the generation of a negative lift force.
The edge of the robot’s head was increased from 0 to 7° with respect to the horizontal plane, a corresponding increase in lift force was observed till it reached zero degrees and the robot was able to come out of the medium at seven degrees.
Source: http://www.gatech.edu/