经济学人下载:无人送货机的防护(1)

Internet shopping makes buying things easier, but has also led to the rise of a new kind of thief: the porch pirate.
网络让购物变得更加容易，但也导致了一种新型偷窃的兴起：包裹窃贼。

Porch pirates scour door steps for deliveries that have been made when a householder was out, and nab them.
包裹窃贼会在住户外出时，在门口的台阶上搜寻投送的快递，然后把快递劫走。

Sometimes, they will stalk delivery vans to do so.
有时他们会跟踪送货车进行偷窃。

Residents of New York City, for example, lose an astonishing 90,000 parcels every day to porch pirates,
例如，根据《纽约时报》的报道，纽约市的居民每天因包裹窃贼

according to a report in the New York Times
而丢失多达9万个包裹。

Porch piracy is a problem that may be solved by the spread of parcel-delivering drones.
无人送货机的普及或许可以解决包裹窃贼的问题。

Because each drone delivery involves a separate journey, rather than having to be fitted into a round,
因为每一架无人机都直送一家货物，而不是来回运送多家，

it will be easier for courier and customer to agree on when a drone should arrive than on the arrival time of a van.
所以快递员和客户更容易就送货时间达成一致，而不是货车何时到达。

However Nirupam Roy and Nakul Garg, a pair of engineers at the University of Maryland,
但是，马里兰大学的两位工程师Nirupam Roy和Nakul Garg

worry that drone deliveries are open to a different sort of piracy—hijacking. A drone in flight is easily upset.
担心无人送货机可能会遭遇另一种类型的盗窃——空中劫持。飞行中的无人机很容易受干扰。

A well-aimed stone, baseball or similar missile is enough to bring it down, permitting its payload to be purloined.
一枚瞄准好的石头、棒球或类似的投掷就足以将其击落，使其运送货物被窃取。

Nor need such stone-throwers have pecuniary motives.
这些扔石头的人也不需要有金钱动机。

Vandalism, or irritation with the very presence of drones, might also provoke pot shots.
破坏公物或对无人机的存在感到不满，都可能会引发枪击事件。

High-flying drones, like those employed by the police for surveillance, will normally be out of range of such activity.
高空飞行的无人机，比如那些被警方用于监视的无人机，通常会超出这种活动的范围。

But parcel drones will have to fly low, at least for part of their journeys.
但是运送包裹的无人机必须低空飞行，至少在运送过程中需要这样。

To counter this risk the pair therefore propose to build a lightweight,
为了应对该风险，两人提议建造一个轻量级的

low-power self-defence mechanism which lets a drone sense a missile fast enough to get out of its way.
低功率自卫机制，让无人机能够迅速感应投掷以躲避开来。

That is nowhere near as easy as it might sound. Drones are lean machines, provided with only enough battery strength,
这远没有听起来那么容易。无人机是一种精简的机器，只有提供足够的电池强度、

computing power and payload-carrying capacity to do the job they are designed for.
计算能力和有效载荷，它们才能完成自己的工作。