阅读理解-第十五篇 肋生双翅机器人学飞行

第十五篇Wing ed〔翅膀〕Robot Learns to Fly

Learning how to fly took nature millions of years of trial〔试验〕and error- but a winged robot has cracked it in only a few hours , using the same evolutionary〔进化的〕principle s〔原理〕.

Krister Wolff and Peter Nordin of Chalmers University of Technology 〔CUT〕in Gothenburg ,Sweden, built a winged robot and set aboue testing whether it could learn to fly by itself, without any pre-programmed data on what flap ping〔上下左右移动、振翅而飞〕is or how to do it.

To begin with the robot just twitch ed（颤动）and jerk ed（猛拉）erratically（不规律地）. But, gradually（逐渐地）, it made movements that gain ed（获得）height. At frrst , it cheat ed - simply standing on its wing tip s（顶端、翼尖）was one early short cut. After three hours , however, the robot abandoned such methods in favor of a more effective flapping technique , where it rotated its wings through 90 degrees and raised them before twist ing them back to the horizontal and push ing down.

"This tells us that this kind of evolution（演变）is capable（能够）of coming Up with flying motion ," says Peter Bentley , who works on evolutionary computing at University College London. But while the robot had worked out how best to produce lift , 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（轻木）wood and covered with a light plastic（塑料）film.Small motors on the robot let it move its wings forwards or backwards , up or down or twist(扭) them in either direction.

The team attach ed（附加）the robot to two vertical rod s（杆）, so it could slide up and down. At the start of a test , the robot was suspend ed by an elastic（有弹性的）band. A movement detector measured how much lift ,if any,at robot produced for any given movement. A computer program fed the robot random instruction s , at the rate of 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 Up and "offspring" sets of instructions were generat ed by swap ping(交换) instructions randomly between successful pairrs. These next-generation instructions were then sent to the robot and evaluate d（评价）before breed ing a new generation , and the process was repeated.

练习:

l. Which of the following is NOT true of what is mention ed 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.

2. How did the 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 land ed not long after the test.

3. Which of the following is nearest to Peter Bentley's view on the winged robot?

AThe winged robot could never really fly.

B The winged robot did not have a motor.

C The winged robot should go through further evolution before it could fly.

D The robot could fly if it were lighter.

4. What measured how much lift the robot produced?

A Two vertical rods.

B A movement detector.

C An elastic band.

D Both B and C.