想要提高托福阅读水平，我们一定要在日常生活中有意识地增加英语阅读量，提升语感和熟练度，这样才能在实际托福考试中游刃有余轻松应对，这其中比较常用也比较方便地一个提升阅读实力的方式就是利用各类英文报刊杂志文章进行精读与泛读练习。下面我们来看一篇经济学人双语文章：无人机送货何时实现。

Future uses

Can drones deliver the goods?

The wait for cargo-carrying drones may be longer than expected

未来应用

无人机能送货吗

对货运无人机的等待可能要长于预期

THERE is a striking disparity between the commercial applications drone companies are pursuing in fields like construction, inspection or agriculture and the public perception of commercial drones. Media coverage is dominated by one particular application: delivery. experimental deliveries of parcels, pizzas and other items conjure up visions of skies abuzz with drones ferrying packages to and fro. But although delivery and logistics companies are interested in drones, many drone companies are not interested in deliveries. “It’s not on our immediate radar,” says Paul Xu of DJI.

无人机公司在建筑、检验或农业等领域追求的商业应用，与商业无人机的公众印象之间存在着显著的差异。媒体报道几乎全都是一个特定的应用：送货。运送包裹、披萨饼和其他物品的试验激起了人们对于空中遍布着往返运送包裹的无人机的想象。然而，虽然运输和物流公司对无人机感兴趣，许多无人机公司对送货的热情却不高。“这不是我们近期要考虑的。”大疆公司的徐华滨说。

Astro Teller, the boss of X, Google’s semi-secret research laboratory, is one of the lucky few to have received a delivery by drone. It was dispatched last September as part of a test carried out in Virginia by Project Wing, Google’s drone-delivery programme. Its machines come in a variety of shapes: some are “tail-sitters”, flying wings capable of flipping upright and hovering; others are fixed-wing drones augmented by vertical-axis rotors like those on a quadcopter. Both designs combine the benefits of a fixed-wing aircraft for efficient long-distance flight with those of a multirotor for hovering and vertical take-off and landing. When delivering a package the drones do not actually land but float above the recipient and use a winch to lower their cargo: in Dr Teller’s case, a freshly prepared burrito.

谷歌半秘密研究实验室X的老板阿斯特罗·泰勒(Astro Teller)是少数收到过无人机送货的幸运儿之一。此次送货是去年9月，谷歌无人机送货项目Project Wing在弗吉尼亚进行测试时完成的。当时所用的机器形状五花八门：有些是“坐式”，可以直立起来并悬停;有些则是固定翼再加上类似于四翼直升机的垂直轴旋翼。这两种设计将固定翼飞机的高效长距离飞行的优点与多旋翼飞机的悬停和垂直起降结合起来。在交付包裹时，无人机实际上并没有落地，而是悬在接收者所在位置的上空，用绞绳把货物放下来。给泰勒送的是一个新鲜的墨西哥卷饼。

Receiving something by drone is “kind of magical”, he says, launching into an impassioned case for drone delivery. Imagine you had a magic elf that could bring you anything you asked for within a minute or two, provided it could fit in a breadbin. You would no longer worry about what to take with you when going out. Nor would you keep common items, like batteries or perishable foodstuffs, on hand at home just in case you needed them. You might not need to own some rarely used objects at all if you could summon them when needed. Rapid drone delivery could thus accelerate the trend from ownership to access in the “sharing economy”, says Dr Teller. He claims delivery drones could be faster, quieter and more environmentally friendly than large delivery trucks. Project Wing now carries out experimental flights daily.

他说，拿到无人机送来的东西确实“有点神奇”，并开始发表对无人机送货的激情演说。想象一下，一个魔法精灵可以在一两分钟内拿来任何你所要的东西，只要它能塞进一个面包盒。你再也不用担心外出时要带什么，也用不着在家里囤积电池或易腐食品以备不时之需。如果那些不常用的东西可以召之即来，你甚至根本就不需要拥有它们。泰勒说，快速无人机送货可能由此加速从所有权转向“共享经济”使用权的趋势。他声称送货无人机可以比大型运输卡车更快、更安静、更环保。Project Wing现在每天都要进行实验飞行。

The technology giant most closely associated with delivery drones is Amazon. When its boss, Jeff Bezos, revealed his plans for drones in December 2013 on “60 Minutes”, an American television programme, they were widely assumed to be a publicity stunt. But Amazon is quite serious: it carried out its first trial delivery to a customer near Cambridge, England, last December—“13 minutes from click to delivery,” says Gur Kimchi, the head of Amazon’s drone effort. In March 2017 it conducted its first delivery demonstration in America, at a conference in Palm Springs. Like Google, Amazon is evaluating a range of different designs, all of which involve the drone lowering its package onto a target in the recipient’s garden or backyard. Logistics firms such as DHL and UPS, as well as some startups, are also looking at drone delivery.

与送货无人机关系最密切的技术巨头是亚马逊。当它的老板杰夫·贝佐斯(Jeff Bezos)在2013年12月的《60分钟》电视节目上公布无人机计划时，人们还普遍认为这是个噱头。但亚马逊是很认真的：去年12月它首次试验送货给英国剑桥附近的一位客户——“从下单到送货共用了13分钟。”亚马逊公司无人机项目的负责人古尔·金姆齐(Gur Kimchi)说。2017年3月，亚马逊在美国棕榈泉举行的一次会议上首次演示了送货。和谷歌一样，亚马逊正在评估一系列不同的设计，所有设计都需要无人机把包裹放到收件人的花园或后院的某个目标物上。DHL和UPS等物流公司以及一些创业公司也在关注无人机送货。

But if widespread drone delivery is to become a reality, many technical and regulatory hurdles must be overcome. These include ensuring that drones do not fall and cause injury, and can land safely if something goes wrong; and preventing collisions with power lines, trees and other aircraft. Moreover, small drones have limited cargo-carrying capacity; not everyone has a garden or backyard; and deliveries require beyond-line-of-sight, autonomous operation, which requires special permission. So at least for now, many drone firms are steering clear. “It’s very challenging, and we do not want to promise something we can’t deliver,” says Mr Xu. “Delivery just bundles together all the hard problems,” says Mr Bry, who worked on Project Wing before leaving to found Skydio. He thinks it could take a decade to solve these problems.

但是，大规模无人机送货要想成为现实，还必须克服许多技术和监管障碍，包括确保无人机不会坠落并造成伤害，在出现问题时能够安全着陆，并防止与电线、树木和其他飞机碰撞。此外，小型无人机承载能力有限;不是每个人都有花园或后院;交付要求超视距自主操作，而这需要特别许可。所以至少到目前为止，很多无人机公司都避开这一领域。徐华滨说：“这很有挑战性，我们不想对交付不了的东西作出承诺。”亚当·布莱(Adam Bry)曾在Project Wing工作，之后离职创办了Skydio。他说：“送货把所有这些困难的问题都绑在了一起。”他认为解决这些问题可能需要十年时间。

One application where drone delivery may make more sense, and is already in use, is ferrying medical supplies to remote areas that are hard to reach by road. Zipline, an American startup staffed by veterans of Google, SpaceX, Boeing and NASA, began delivering medical supplies in rural Rwanda using fixed-wing drones in October 2016. It has an agreement with the government to deliver blood products to 21 transfusion clinics from two bases, the first of which is already serving five clinics. Zipline’s drones can fly 150km on a single charge and work in rain and winds of up to 30km an hour. They are launched using a catapult, fly below 150 metres (500 feet) and drop cargo packages weighing 1.5kg by parachute.

无人机送货可能有一个更有意义的用途，那就是将医疗用品运送到陆路难以到达的偏远地区。这已经发生了。由谷歌、SpaceX、波音和NASA的老员工组建的美国创业公司Zipline从2016年10月开始使用固定翼无人机向卢旺达农村提供医疗用品。该公司与卢旺达政府达成协议，从两个基地向21个输血诊所提供血液制品，其中第一个基地已经为五个诊所提供了服务。Zipline无人机充电一次可飞行150公里，并可在雨中及风速高达每小时30公里的情况下工作。它们使用弹射器发射，飞行高度低于150米，并用降落伞投放重1.5公斤的货物包裹。

Rolling out the service means mapping the best routes for the aircraft, which fly autonomously, co-ordinating with military and civilian authorities, training clinic staff to receive cargo and reassuring the local communities along the route. Whether all this is economically viable, or just a publicity stunt by Rwanda’s tech-loving government, is unclear. But the company is talking to governments in other countries about operating similar services, focusing on medical deliveries outside urban areas. It hopes to change public perceptions of the word “drone”. Zipline’s Justin Hamilton says one of the firm’s engineers once told him that he used to work on drones that drop bombs, “and now he builds drones that drop blood.”

要开展这项服务，就要将最佳路线告诉自主飞行的飞机，与军方和政府协调，培训诊所工作人员接收货物，并让沿线社区放心。这一切是真的在经济上可行，还是仅仅是热爱科技的卢旺达政府的噱头，尚不得而知。但是，该公司正在与其他国家的政府进行关于提供类似服务的沟通，重点关注城市以外的医疗递送。它希望改变公众对“无人机”这个词的看法。Zipline的贾斯汀·汉密尔顿(Justin Hamilton)说，公司的一名工程师曾经告诉他，自己以前造的是投掷炸弹的无人机，“现在他造的是投放血液的无人机了。”

Other startups say that drone delivery in urban areas is already possible—but using drones moving on the ground rather than in the air. Starship Technologies, based in Estonia, and Dispatch, based in California, have both developed wheeled, coolbox-sized drones that trundle along pavements to make local deliveries. Starship’s drones are being tested in several cities around the world, and Dispatch is about to begin tests in the San Francisco Bay Area. Both firms use a “partial autonomy” model, meaning that their drones can be remotely piloted for some or all of a route. As the drone approaches its destination, the recipient receives a smartphone alert, and when it arrives he uses his phone to pop open a lockable compartment to retrieve the cargo.

其他创业公司表示，在城市中用无人机送货已经成为可能——但使用的是在地上移动而非空中飞行的无人机。总部设在爱沙尼亚的Starship Technologies公司和位于加州的Dispatch公司都开发了了手提箱大小的轮式无人机，在人行道上颠簸着做小范围送货。Starship的无人机正在世界各地的几个城市进行测试，Dispatch则即将在旧金山湾区开始测试。两家公司都使用“部分自治”模式，这意味着它们的无人机可以在部分路线或全程接受远程操控。无人机接近目的地时，收件人会在智能手机上收到提示;到达后，收件人可以用手机打开一个可锁定的货舱来收取货物。

What if people steal the drone? Anyone who tries, says Stav Braun of Dispatch, has “just stolen a homing beacon”. A bigger concern, she says, is ensuring that the robot is courteous and people feel safe around it. But so far the response has been positive.

如果有人把无人机偷走了怎么办?Dispatch的斯塔夫·布朗(Stav Braun)说，任何试图偷走它的人“只是偷走了一个追踪器”。她说，更大的问题在于确保机器人有礼貌，人们在它身边会感到安全。不过到目前为止，反响都还不错。

Instant gratification

Clement Jambou of Unsupervised.ai, a French delivery-drone startup, thinks the steps and kerbs of urban environments will be too difficult for wheeled robots to navigate, so his firm’s delivery drone has legs instead and resembles a dog. He may disagree with Dr Teller on the best way to set about it, but Mr Jambou has a very similar vision for fast, cheap drone delivery. For example, he imagines people renting rather than buying clothes, tools and other household items, dispatched by drone from a neighbourhood depot when needed.

即时满足

法国送货无人机创业公司Unsupervised.ai的克莱芒·让布(Clement Jambou)认为，轮式机器人难以应付城市环境中的台阶和路沿，所以他的公司的送货无人机有腿，看起来就像一只狗。让布未必同意泰勒关于最佳送货方式的看法，但对于快速、廉价的无人机送货前景却所见略同。例如，他想象人们会租借而不是购买衣物、工具和其他家庭用品，无人机会在需要时从临近的仓库里为他们发货。

Dr Teller, for his part, is confident that the technical and safety obstacles to flying delivery drones can be overcome. But it will be a gradual process involving “lots of data and demonstration” to satisfy regulators. “The magical elf won’t change the world unless it can go beyond visual line-of-sight, fly over people and have a small number of operators responsible for a large number of vehicles,” he says, none of which is allowed under current regulations. Google is working on making its drones resilient to the failure of a single rotor, battery or motor, the loss of GPS coverage and other potential problems. “We are building up evidence that we can do this safely,” he says. That will take a while, but Google expects its “moonshots” to take up to a decade to pay off. Work on Project Wing began in 2012.

泰勒博士则对于克服飞行送货无人机的技术和安全障碍信心满满。但这将是一个渐进的过程，涉及“大量数据和演示”以满足监管机构的要求。他说：“这个魔法小精灵不会改变世界，除非它能超越视距，在人们头顶上方飞过，并让少数操作员负责大量飞行器。”而现行规定下，这些都不被允许。谷歌正在努力使其无人机能够克服单个旋翼、电池或电机故障、失去GPS信号等潜在问题。“我们正在积累证据，证明我们能够安全地做这件事。”他说。这需要一段时间，但谷歌预计其“登月计划”需要十年才能得到回报。Project Wing的工作始于2012年。

The disagreement over the viability of delivery drones, then, is mostly a matter of timing. For companies that wish to put drones to work now, delivery is not a good bet. But for logistics companies it makes sense to start exploring the possibilities. The end result may well be a hybrid system of delivery trucks that arrive in a neighbourhood and disgorge flying and wheeled drones.

因此，对无人机送货可行性的分歧主要是时间问题。对于那些希望让无人机现在就服役的公司而言，送货不是一个好的赌注。但对于物流公司来说，开始探索这种可能性是有意义的。最终的结果很可能是一个混合系统：送货卡车开到一个社区附近，然后分发出飞行和轮式无人机。

Deliveries are just one of the proposed uses of drones that seem speculative or impractical now but may become significant in future. Facebook, like Google and Amazon, is also investing in drones, but not for delivery: instead its drone, called Aquila, is a huge solar-powered machine intended as a communications relay, to extend internet access to parts of the world that lack connectivity. This will have health and educational benefits, the social-media giant says, but will also help it sign up more users. Aquila made its first test flight in June 2016. Facebook’s boss, Mark Zuckerberg, explained in a blog post afterwards that his goal is “a fleet of Aquilas flying together at 60,000 feet, communicating with each other with lasers and staying aloft for months at a time”, beaming internet access over wide areas.

有些无人机应用目前看似投机或不切实际，但未来可能变得重要，送货就是其中一种。和谷歌和亚马逊一样，Facebook也投资于无人机，但不是为了送货：它名为“Aquila”的无人机是一个由太阳能供电的巨大机器，将作为通信中继站，将互联网提供给世界上尚未通网的地方。这家社交媒体巨头表示，这将有益于健康和教育，也能为Facebook吸引更多新用户。Aquila于2016年6月首次试飞。Facebook的老板马克·扎克伯格事后在一篇博文中解释说，他的目标是“一队Aquila飞行在六万英尺的高空，相互之间使用激光通信，一次可飞行数月”，为广大地区发射互联网连接。

Making all this work is a lofty goal. In November it emerged that the prototype Aquila had been substantially damaged on landing, triggering an investigation by flight-safety inspectors. And getting permission to fly such aircraft over any populated areas will not be easy. In January Google scrapped its own high-altitude communications-relay drone, Titan.

让这一切变成现实是一个崇高的目标。11月，Aquila原型在着陆时严重损坏，招致飞行安全检查员的调查。要获得许可在任何人口稠密地区放飞这种飞行器也非易事。谷歌于1月份放弃了自己的高空通信中继无人机“Titan”。

Dr Teller says that Google now sees more promise for extending internet access in high-altitude balloons; they are easier to keep airborne and much more lightly regulated than drones. Military drones such as the Global Hawk can already act as telecoms relays, so that part of the technology is proven; the challenge is to harness solar power to keep drones aloft for weeks or months, not just a day or two. Large, lightweight UAVs can theoretically use solar power to remain in the air for weeks at a time; a prototype Zephyr drone, built by Airbus, Europe’s aviation giant, stayed aloft for 14 days during a test flight in 2010.

泰勒称，谷歌如今认为通过高空气球扩展互联网接入更有希望：它们更容易保持飞行，监管也比无人机宽松很多。“全球鹰”这样的军用无人机已经可以充当电信中继站，所以这部分技术已得到证明。挑战在于利用太阳能来保持无人机飞行数周或数月，而不仅仅是一两天。庞大而轻量的无人机在理论上可以使用太阳能一次滞空数周。2010年，欧洲航空巨头空中客车公司建造的Zephyr无人机原型在一次试飞时在空中停留了14天。

High-altitude drones have also been proposed as a way to generate electricity, because strong winds blow more reliably well above the ground. Known as wind drones or energy kites, such drones are tethered so that cables can deliver the electricity back to the ground. Makani, a startup acquired by Google in 2013, reckons a single energy kite can generate 50% more electricity than a single wind turbine while using only 10% of the materials. Each Makani drone, which resembles a wing with eight propellers, weighs 11 tonnes, compared with about 100 tonnes for a comparable 600kW turbine. This approach is being pursued by other firms too, including Ampyx Power and Kite Power Systems, both backed by E.ON, a German utility. Tethered drones on a smaller scale are also being considered for indoor use in warehouses, where they might help with stocktaking. Flying indoors neatly sidesteps many regulatory problems, and supplying power via tethers does away with the need for recharging. But GPS cannot be used for positioning.

也有人提出使用高空无人机来发电，因为高空的强风更为可靠。这种无人机被称为风力无人机或电力风筝，连有系索以便电缆将电力送回地面。Makani是谷歌于2013年收购的一家创业公司，它估算，一个电力风筝的发电量比一个风力涡轮多50%，但使用的材料仅为后者的10%。每个Makani无人机有八个螺旋桨，重11吨，而同样的600千瓦涡轮机则重约100吨。其他公司也在追求这种方法，包括Ampyx Power和Kite Power Systems，两家公司都得到了德国公用事业公司E.ON的支持。还有人考虑将较小的有线无人机用于仓库中的室内应用，比如用它们来帮助盘点。室内飞行漂亮地回避了许多监管问题，且通过系绳供电免除了充电的需求，不过就不能用GPS来定位了。

At the lowest end of the spectrum are insect-like drones, just a few centimetres across, that could be used for surveillance inside buildings, search and rescue, or even pollinating plants. Building very small drones is hard because the technology used in larger drones cannot simply be scaled down; different approaches are needed. In a paper published in February in the journal Chem, Japanese researchers explained how insect-sized drones covered in hairs coated with a special gel picked up pollen from one plant and deposited it on another. They concluded that robotic pollinators might offer a remedy for the decline in honeybee populations.

整个无人机谱系最低端的是昆虫般的无人机，只有几厘米大小，可用于建筑物内的监视、搜救甚至为植物授粉。制作非常小的无人机并非易事，因为大型无人机使用的技术并不能简单地按比例缩小，而是需要不同的手段。日本研究人员2月份在《Chem》杂志上发表了一篇论文，文中解释了昆虫大小、表面覆盖毛发(毛发上涂有一种特殊的凝胶)的无人机如何从一棵植物中采集花粉再投放到另一棵植物上。他们得出结论称，传粉机器人也许可以为蜜蜂数量的减少提供一种补救措施。

Perhaps the most far-out proposal to date is to use drones to carry human passengers in self-flying taxis. This is harder than using drones for package delivery, because it raises safety concerns for people in the air, not just on the ground. EHang, a Chinese drone firm, hopes to test its one-person drone, which resembles a giant quadcopter with a passenger compartment, in Dubai in July. Other companies, including Airbus, Uber and Kitty Hawk, have proposed similar “flying car” drones. Dario Floreano, a robotics professor at the Swiss Federal Institute of Technology (see next article), has been thinking about passenger drones as part of the European Union’s “myCopter” project. Packages, he says, can withstand sudden accelerations during flight that humans cannot, which makes path-planning and obstacle avoidance more difficult. And the limited energy density of batteries may restrict the range of passenger drones to intra-city hops.

也许迄今为止最奇怪的提议是把无人机作为自驾空中出租车来运送乘客。这比使用无人机递送包裹更困难，因为除了地面人员的安全，它还引发了空中人员的安全问题。中国无人机公司亿航希望7月份在迪拜测试其单人无人机，这个机器像是一个带座舱的巨型四翼直升机。其他公司，包括空中客车、优步和Kitty Hawk都提出了类似的“飞行车”无人机设想。瑞士联邦理工学院的机器人学教授达里奥·弗洛雷诺(Dario Floreano)一直在考虑将载客无人机作为欧盟“myCopter”项目的一部分。他说，包裹可以承受人类所不能承受的飞行时突然加速，这使得规划路径和避让障碍的任务变得更加艰巨。电池能量密度有限，可能会将载客无人机的运作范围限制在城市内。

It is a big leap from today’s drones to these sorts of uses. Trying to imagine how drones will evolve, and the uses to which they will be put, is a bit like trying to forecast the evolution of computing in the 1960s or mobile phones in the 1980s. Their potential as business tools was clear at the time, but the technology developed in unexpected ways. The same will surely be true of drones.

从今天的无人机到此类用途还需要一个巨大的飞跃。要想象无人机将如何演变、将会有什么用途，就有点像是在20世纪60年代预测计算能力的演化，或是在20世纪80年代预测手机的变化。它们作为商业工具的潜力在当时已经很清楚，但技术的发展却出乎意料。无人机的发展必定也是如此。