Washington, September 3 : Computer scientists from Stanford University in the US have developed an artificial intelligence system that enables robotic helicopters to teach themselves to fly difficult stunts by watching other helicopters perform the same maneuvers.
The result is an autonomous helicopter than can perform a complete airshow of complex tricks on its own.
According to Andrew Ng, the professor directing the research of graduate students Pieter Abbeel, Adam Coates, Timothy Hunter and Morgan Quigley at Stanford, the stunts are by far the most difficult aerobatic maneuvers flown by any computer controlled helicopter.
The dazzling airshow is an important demonstration of "apprenticeship learning," in which robots learn by observing an expert, rather than by having software engineers peck away at their keyboards in an attempt to write instructions from scratch.
Stanford's artificial intelligence system learned how to fly by "watching" the four-foot-long helicopters flown by radio control pilot Garett Oku.
"Garett can pick up any helicopter, even ones he's never seen, and go fly amazing aerobatics. So the question for us is always, why can't computers do things like this?" Coates said.
For answering their own question, Abbeel and Coates sent up one of their helicopters to demonstrate autonomous flight.
The aircraft, brightly painted Stanford red, is an off-the-shelf radio control helicopter, with instrumentation added by the researchers.
For five minutes, the chopper, on its own, ran through a dizzying series of stunts beyond the capabilities of a full-scale piloted helicopter and other autonomous remote control helicopters.
The artificial-intelligence helicopter performed a smorgasbord of difficult maneuvers: traveling flips, rolls, loops with pirouettes, stall-turns with pirouettes, a knife-edge, an Immelmann, a slapper, an inverted tail slide and a hurricane, described as a "fast backward funnel."
One of the most amazing maneuver performed by the flying machine was the "tic toc," in which the helicopter, while pointed straight up, hovers with a side-to-side motion as if it were the pendulum of an upside down clock.
According to Eric Feron, a Georgia Tech aeronautics and astronautics professor who worked on autonomous helicopters while at MIT, "I think the range of maneuvers they can do is by far the largest in the autonomous helicopter field."
"But what's more impressive is the technology that underlies this work. In a way, the machine teaches itself how to do this by watching an expert pilot fly. This is amazing," he added.
The helicopter carries accelerometers, gyroscopes and magnetometers, the latter of which use the Earth's magnetic field to figure out which way the helicopter is pointed. he exact location of the craft is tracked either by a GPS receiver on the helicopter or by cameras on the ground.