Robot Spy Can Survive Battlefield Damage
Peter Bentley and Siavash Haroun Mahdavi of University College London have developed a self-healing snake-like robot as a possible military reconnaissance tool.
The snakebot consists of modular vertebral units, each containing three independent longitudinal “muscles” fashioned from nitinol–a shape-memory alloy of nickel and titanium whose crystal structure contracts when subjected to an electric current, and resumes its original configuration when the current is removed; applying the current to specific nitinol wires causes the robot to move in a specific direction. The snakebot is also equipped with a shape-changing antenna to transmit audio and video.
So that other vertebral segments can take over for those that are damaged, Bentley and Mahdavi employ a genetic algorithm.
Each series of movements the robot makes is determined by a digital chromosome comprised of a primarily random binary digit correlating to a muscle wire. The genetic algorithm starts out with 20 chromosomes, and tests them to ascertain the two fittest chromosomes (those that best achieve the desired movement), which are retained while the remainder are shuffled or subjected to random mutation.
The process is repeated over successive generations until a performance plateau is achieved, as signaled by a tapering off of improvement, according to Mahdavi.
The development of the snakebot is being underwritten by BAE Systems, which aims to use it as an inexpensive battlefield surveillance device that can be deployed from helicopters.
Abstracted by the National Law Enforcement and Corrections Technology Center(NLECTC) from the New Scientist (08/20/03); Graham-Rowe, Duncan.
