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发表时间：2014/4/11 9:33:11 来源：互联网点击关注微信：

Winged Robot Learns to Fly

Learning how to fly took nature millions of years of trial and error1—but a winged robot has cracked2 it in only a few hours, using the same evolutionary principles.

Krister Wolff and Peter Nordin of Chalmers University of Technology (CUT) in Gothenburg, Sweden, buit a winged robot and set about3 testing whether t could learn to fly by itself, without any preprogrammed data on what flapping is or how to do it.

To begin with, the robot just twitched and jerked erratically. But, gradually, it made movements that gained height. At first, it cheated — simply standing on its wing tips was one early short cut5. After three hours, however, the robot abandoned such methods in favor of6 a more effective flapping technique, where it rotated its wings through 90 degrees and raised them before twisting them back to the horizontal and pushing down.

“This tells us that this kind of evolution is capable of coming up8 with flying motion,” says Peter Bentley, who works on evolutionary computing at University College London. But while9 the robot had worked out how best to produce lift{10}, it was not about to take off. “There’s only so much that evolution can do, Bentley says. This thing is never going to fly because the motors will never have the strength to do it,”he says.

The robot had metre—long wings made from balsa wood and covered with a light plastic film. Small motors on the robot let it move its wings forwards or backwards, up or down or twist them in either direction.

The team attached the robot to two vertical rods, so it could slide up and down. At the start of a test, the robot was suspended by an elastic band. A movement detector measured how much lift, if any{11}, the robot produced for any given movement.

A computer program fed the robot random instructions{12}, at the rate of {13} 20 per second, to test its flapping abilities. Each instruction told the robot either to do nothing or to move the wings slightly in the various directions.

Feedback from the movement detector let the program work out which sets of instructions were best at producing lift. The most successful ones were paired up14 and “offspring”sets of instructions15 were generated by swapping instructions randomly between successful pairs. These nextgeneration instructions were then sent to the robot and evaluated before breeding a new generation, and the process was repeated.

41 Which of the following is NOT true of what is mentioned about the winged robot in the second paragraph?

A The two professors of CUT built the winged robot.

B The two professors of CUT tested whether the winged robot could learn to fly.

C The two professors of CUT programmed the data on how the robot flapped its wings.

D The two professors of CUT tried to find out if the robot could fly by itself.

42 How did te robot behave at the beginning of the test?

A It rotated its wings through 90 degrees.

B It twitched but gradually gained height.

C It was twitched and broke down.

D It landed not long after the test.

43 Which of the following is nearest to Peter Bentleys view on the winged robot?

A The winged robot could never really fly.