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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, built a winged robot and set about3 testing whether it could learn to fly by itself, without any pre-programmed data on what flapping is or how to do it.

To begin with4, 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 of7 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 lift10, 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 any11, the robot produced for any given movement. A computer program fed the robot random instructions12, at the rate of13 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.

詞匯: flap /flAp/v.振翅;拍打，拍動(dòng) rotate /rEu5teit/v.旋轉(zhuǎn)，轉(zhuǎn)動(dòng) twitch /twitF/v.猛抽;抽動(dòng) balsa /5bRlsE/n.輕木 jerk /dVE:k/v.猛拉;急扭 offspring /5RfsprIN/n.后代;結(jié)果，產(chǎn)物 erratically /i5rAtik/adj.飄忽不定地;不穩(wěn)定地 swop /swCp/v.交換;交流

注釋?zhuān)?/p>

1. Learning how to fly took nature millions of years of trial and error:自然界里的飛行學(xué)習(xí)用了幾百萬(wàn)年的時(shí)間反復(fù)實(shí)踐和磨煉。

2. crack: to break through (an obstacle) in order to win acceptance or acknowledgement: 突破(障礙)

3. set about:開(kāi)始做，著手

4. To begin with: 首先

5. short cut: 捷徑

6. in favor of:原意為“贊成;支持”。這里，…… the robot abandoned such methods in favor of a more effective flapping technique意為:……這個(gè)機(jī)器人放棄了這樣的方法，而去使用一種更為有效的扇動(dòng)翅膀的技術(shù)。

7. be capable of: [指物]有可能，可以……

8. come up: to manifest itself; arise 出現(xiàn)。

9. while:雖然，盡管

10. lift:升高

11. if any:若有的話(huà)。確切意思是 :如果它能升高的話(huà)。

12. ... fed the robot random instructions:給機(jī)器人輸入隨意設(shè)定的指令。 fed是feed的過(guò)去式。

13. at the rate of:以……的速度

14. pair up:把……配成一對(duì)

15.“offspring”sets of instructions:指的是將成功的指令配對(duì)后的結(jié)果。“ offspring”本來(lái)是后代的意思，在此修飾sets of instructions，所以加了雙引號(hào)。練習(xí):

1. 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.

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 landed not long after the test.

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

5. What does “the process” appearing in the last paragraph refer to? A Pairing up successful inst ructions. B Sending instructions to the robot. C Generating new sets of instructions for evaluation. D All the above.

答案與題解 :

1. C A、B、D在第二段中都提到過(guò)。 C是錯(cuò)誤的，因?yàn)槲闹姓f(shuō)，教授們測(cè)試機(jī)器人是否會(huì)自己學(xué)會(huì)飛行，而且預(yù)先沒(méi)有對(duì)翅膀扇動(dòng)的方式進(jìn)行數(shù)據(jù)設(shè)定。

2. B第三段描述了機(jī)器人如何學(xué)習(xí)飛行的過(guò)程。第一句和第二句是問(wèn)題的答案。

3. A第四段主要是 Peter Bentley對(duì)飛行機(jī)器人的看法。他認(rèn)為前文描述的進(jìn)化過(guò)程只能使機(jī)器人有一些飛行的動(dòng)作，而要讓其起飛則永遠(yuǎn)不可能，因?yàn)椴豢赡苡腥绱舜蠊β实陌l(fā)動(dòng)機(jī)。所以 A是正確選項(xiàng)

4. B答案在第六段的第三句中。

5. D文章昀后一段具體描述在機(jī)器人的進(jìn)化過(guò)程中，指令的進(jìn)化過(guò)程。成功的指令配對(duì)后產(chǎn)生新一代的指令，將指令輸入機(jī)輯人，經(jīng)篩選再進(jìn)行成功指令配對(duì)，再產(chǎn)生新一代指令，如此反復(fù)進(jìn)行。所以 D是正確選項(xiàng)。