The research has shown, among other things, that a free wrist at the end of the flipper holds a significant advantage over a fixed wrist.
"One of the main findings of our paper was that when the robot was fitted with a free wrist, it was able to move more effectively over the ground as it allowed the flipper to remain locked in place within a solid region of sand and thus disturbed less material during the forward thrust.
"With a fixed wrist, the robot also interacts with the ground that has already been disturbed by its previous steps, which hinders its movement," continued Professor Goldman.
These conclusions were backed up by real-life footage of hatchling loggerhead sea turtles taken by study co-author, Nicole Mazouchova, during a six week field-study on Jekyll Island, Georgia, which showed that the sea turtles experienced similar failures.
Mazouchova believes that further robot testing could help in turtle conservation biology. She said: "The natural beach habitat of hatchling sea turtles is endangered by human activity. Robot modelling can provide us with a tool to test environmental characteristics of the beach and implement efforts for conservation."
As well as the wrist flexibility, the researchers also investigated the different depths to which the flipper penetrated the poppy seeds, while also measuring the body lift, flipper thrust, the drag of the robot's base and the amount of ground that was disturbed. The results showed that the relationship between each of these aspects is not trivial, but can, nevertheless, be understood using relatively simple models.
Co-author of the study Dr Paul Umbanhowar said: "Our modelling shows that flipper driven locomotion on soft ground is largely determined by simp
|Contact: Michael Bishop|
Institute of Physics