| 查看: 361 | 回复: 0 | |||
tt.yao荣誉版主 (知名作家)
爱思考的小强
|
[交流]
It’s a Bird, It’s a Plane, It’s a … Spy?
|
|
Science 23 March 2012: Vol. 335 no. 6075 p. 1433 DOI: 10.1126/science.335.6075.1433 NEWS FOCUS It’s a Bird, It’s a Plane, It’s a … Spy? If a hummingbird follows you into a building, one of two things is going on: Either your perfume is too strong, or the world’s smallest spy plane is on your tail. In 2011, AeroVironment, a company founded by Paul MacCready, the inventor of the fi rst human-powered aircraft to cross the English Channel, unveiled a new crewless aircraft called the Nano Hummingbird. With a wingspan of 17 centimeters and a weight of 19 grams, the robot is hefty for a hummingbird. But it can hover in place and fl y in any direction (including backward) as fast as 18 kilometers per hour. It can fl y through doorways and can be steered by a remote pilot using only video from an onboard camera. All of these abilities met or exceeded the targets for a secondgeneration “nano air vehicle” funded by the U.S. Defense Advanced Research Projects Agency. Very small ornithopters like the Nano Hummingbird face different challenges from their larger kin. As a fl yer (animal or robot) gets smaller, fl ying becomes more and more like swimming. Less energy goes to lift and more to thrust. Instead of sculpted airfoils, the wings can and should be simple, rapidly beating membranes. For robots, miniaturization of components and power sources may impose the biggest constraint. A real hummingbird can fl y across the Gulf of Mexico without stopping; the Nano Hummingbird can go for only 11 minutes. The main role envisioned for nano air vehicles is military surveillance and reconnaissance. But they could also be used for civilian applications such as search and rescue or environmental monitoring (for example, inside crippled nuclear reactors). Miniature devices have taken off in the past decade. In 2002, the dragonfl y-like Mentor, developed at the University of Toronto and SRI International, demonstrated hovering fl ight. In 2006, the (also dragonfl y-like) DelFly, developed at Delft University of Technology in the Netherlands, added a camera and forward fl ight; later versions have shrunk to 3 grams and a 10-centimeter wingspan. Nano fl yers aren’t yet fi t for duty, however. “The Hummingbird is way cool. I can’t say enough good things about it,” says Ephrahim Garcia, an engineer at Cornell University. “But it has a limited endurance.” Eleven minutes is not much time to scan a building for insurgents or earthquake survivors. Even so, Garcia adds, “Everything doesn’t have to be practical. We can learn a lot about fl ow-structure interaction from these devices.” –D.M.  [ Last edited by tt.yao on 2012-3-23 at 21:46 ] |
回复此楼» 本帖附件资源列表
-
欢迎监督和反馈：小木虫仅提供交流平台，不对该内容负责。
本内容由用户自主发布，如果其内容涉及到知识产权问题，其责任在于用户本人，如对版权有异议，请联系邮箱：xiaomuchong@tal.com - 附件 1 : 1433.full.pdf
2012-03-23 21:41:12, 143.5 K
» 猜你喜欢
求助Fe-TCPP、Zn-TCPP的CIF文件，或者CCDC号
已经有0人回复
-
XPS/?λXPS
已经有0人回复
-
金属材料论文润色/翻译怎么收费?
已经有268人回复
-
河北大学-26年秋季入学化学博士招生
已经有0人回复
-
招收2026年入学博士研究生
已经有10人回复
-
哈尔滨工程大学材化学院国家级青年人才-26年硕士招生/调剂招生
已经有2人回复
找到一些相关的精华帖子，希望有用哦~
Beauty is a mystery. You can neither eat it nor make flannel out of it
已经有16人回复
- To buy or not to buy, it's a ?
已经有33人回复
- It's a riddle about love.
已经有15人回复
- People say it's difficult to maintain a long-term realation nowadays.
已经有5人回复
- Hey, it's you!!! talk with me here
已经有25人回复
- It's too hot today!
已经有20人回复
- I doun't want to lose you ,it's from my deep heart .
已经有17人回复
- 【Pure water】I took it just now. It’s for you.
已经有22人回复
- 【Share】It's a Good Day!
已经有39人回复
- 【Discussion】So it really does not matter to other’s being or not being?
已经有5人回复
- 【Funny】It's gelivable! The whole world's speaking Chinese
已经有10人回复
- 【Share】It 's really not easy to pursue Ph.d in Foreign country
已经有16人回复
- It's easy to cook for me(sunflower3127's diary)
已经有11人回复
点击这里搜索更多相关资源科研从小木虫开始，人人为我，我为人人
