首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Earthquake survivors trapped in rubble could one day be saved by an unlikely rescuer: A robotic caterpillar that burrows its way
Earthquake survivors trapped in rubble could one day be saved by an unlikely rescuer: A robotic caterpillar that burrows its way
admin
2014-01-27
30
问题
Earthquake survivors trapped in rubble could one day be saved by an unlikely rescuer: A robotic caterpillar that burrows its way through debris. Just a few centimeters wide, the robot relies on magnetic fields to propel it through the kind of tiny crevices that would foil the wheeled or tracked search robots currently used to locate people trapped in collapsed buildings.
The caterpillar’ s inventor, Norihiko Saga of Akita Prefectural University in Japan, will demonstrate his new method of locomotion at a conference on magnetic materials in Seattle. In addition to lights and cameras, a search caterpillar could be equipped with an array of sensors to measure other factors—such as radioactivity or oxygen levels—that could tell human rescuers if an area is safe to enter.
The magnetic caterpillar is amazingly simple. It moves by a process similar to peristalsis, the rhythmic contraction that moves food down your intestine. Saga made the caterpillar from a series of rubber capsules filled with a magnetic fluid consisting of iron particles, water, and a detergent-like surfactant, which reduces the surface tension of the fluid. Each capsule is linked to the next by a pair of rubber rods. The caterpillar’ s guts are wrapped in a clear, flexible polymer tube that protects it from the environment.
To make the caterpillar move forwards, Saga moves a magnetic field backwards along the caterpillar. Inside the caterpillar’s "head" capsule, magnetic fluid surges towards the attractive magnetic field, causing the capsule to bulge out to the sides and draw its front and rear portions up. As the magnetic field passes to the next capsule, the first breaks free and springs forward and the next capsule bunches up. In this way, the caterpillar can reach speeds of 4 centimeters per second as it crawls along.
Moving the magnetic field faster can make it traverse the caterpillar before all the capsules have sprung back to their original shapes. The segments then all spring back, almost but not quite simultaneously.
Saga plans to automate the movement of the caterpillar by placing electromagnets at regular intervals along the inside of its polymer tube. By phasing the current flow to the electromagnets, he’ 11 be able to control it wirelessly via remote control. He also needs to find a new type of rubber for the magnetic capsules, because the one he’ s using at the minute eventually begins to leak.
But crawling is not the most efficient form of locomotion for robots, says Robert Full of the University of California at Berkeley, an expert in animal motion who occasionally advises robotics designers. "If you look at the energetic cost of crawling, compared to walking, swimming or flying, crawling is very expensive, " he says. Walking, on the other every step, energy is conserved in the foot and then released to help the foot spring up.
Saga acknowledges this inefficiency but says his caterpillar is far more stable than one that walks, rolls on wheels or flies. It has no moving parts save for a few fluid-filled rubber capsules. Biped robots and wheeled robots require a smooth surface and are difficult to miniaturize, and flying robots have too many moving parts. "My peristaltic crawling robot is simple and it works, " he says.
From this passage, we can learn that______.
选项
A、a robotic caterpillar can crawl by a pair of rubber rods
B、when a caterpillar moves, the magnetic field moves backwards along it
C、the environment couldn’ t influence a robotic caterpillar’ s guts, which are wrapped in a capsule
D、crawling is very stable and efficient, and when it moves, only a few elements are needed
答案
B
解析
由第四段第一句“To make the caterpillar move forwards,Saga moves a magnetic field backwards along the caterpillar.”可以看出,磁场会向后移动,从而使机器虫移动。故应选B。
转载请注明原文地址:https://kaotiyun.com/show/QRXd777K
本试题收录于:
公共英语五级笔试题库公共英语(PETS)分类
0
公共英语五级笔试
公共英语(PETS)
相关试题推荐
WhySoManyChildrenInmanyofthedevelopingcountriesinAfricaandAsia,thepopulationisgrowingfast.Thereasonfort
IncomeTaxFormanyyoungAmericans,graduatingfromcollegemeansfindingajob,movingoutofthedormroomandbeginning
Psychologiststakecontrastiveviewsofhowexternalrewards,from(31)praisetocoldcash,affectmotivationandcreativity.B
Psychologiststakecontrastiveviewsofhowexternalrewards,from(31)praisetocoldcash,affectmotivationandcreativity.B
Thepassagemainlydiscusses______.Theauthorwouldmostlikelyagreewithwhichofthefollowingstatements?
Tostartanewbusiness,youshouldfirst______.
Thespeakersaysitisnecessarytotalkabouthaybecause
______islocatedintheheartofGreenwichVillage?______offerschancesforstudentstoattendtheatersandballetperforman
TherecentsocialandeconomicchangesintheU.S.havegreatimpactonalltheAmericanhousingsystem.
Growingupwithoutafatheraroundcanpresentalotofchallengestoagirl.Quiteapartfromthebehaviourproblemsandlower
随机试题
火与热的主要区别是()(2000年第124题)
在____中,用户一般不直接操纵计算机,而是将作业提交给系统操作员。由操作员将作业成批装入计算机,然后由操作系统按照一定的原则执行作业,并输出结果。最后由操作员将作业运行结果交给用户。
直肠癌最常见的临床症状是()
十六进制7EH的二进制代码形式是()。
素有世界“音乐之都”美称的维也纳金色大厅第一次迎接的中国民族声乐的歌唱家是()。
根据资料,回答下列问题:下列说法错误的是()。
打印机中使用的彩色空间是(1),彩色电视机中使用的彩色空间是(2)。
以下是while语句的基本形式:while(表达式){语句;)其中“表达式”()。
KB(千字节)是度量存储器容量大小的常用单位之一,1KB等于()。
Northernmarshesarebeingturnedintoempty,desecratedmudflatwasteland.Theculprit?Snowgeese.Thesemarshesaretheb
最新回复
(
0
)