A photo shows a white self-driving car obscured by rain coming from nozzles above it, with people standing in the background to watch. Image: SMART A self-driving car designed and built by the Singapore-MIT Alliance for Research and Technology (SMART) passes through CETRAN's rain simulator.
图片:SMART由新加坡 - 麻省理工学院研究与技术联盟(SMART)设计和制造的自动驾驶汽车通过CETRAN的雨模拟器。

In the tropical midday heat, I squint to take in the two-hectare test course before me. Here at Singapore's autonomous vehicle (AV) test center, there's no shortage of ways to put driverless vehicles through their paces---with slopes, crosswalks, bus lanes, traffic junctions, and even a crank course consisting of sharp 90-degree turns.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
在热带正午的炎热中,我眯着眼睛看着我面前的两公顷的测试课程。在新加坡的自动驾驶汽车(AV)测试中心,通过斜坡,人行横道,公交车道,交通枢纽,甚至是由90度急转弯组成的曲柄路线,都可以轻松驾驶无人驾驶车辆。 {#文档内部-GUID-021e4442-7fff-部43ac-85c0-55132eeea634}

But it's an unassuming structure at the far end of the center that catches my eye. There stands a thin metal frame nearly 40 meters long, split into nine sections. It looks like a series of empty door frames. Atop each section sits three nozzles, together capable of releasing up to 150 milliliters of water per hour.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

It's a rain simulator---one of the few found in AV test centers around the world.
这是一个雨模拟器 - 世界各地AV测试中心中为数不多的模拟器之一。CETRAN, or Singapore's Centre of Excellence for Testing and Research of AVs, also has a flood simulator. And for the first time since the center's opening in late 2017, those simulators will soon be put to use as two companies, including MIT startup
,或新加坡AVs测试和研究卓越中心,也有洪水模拟器。自该中心于2017年底开业以来,这些模拟器将很快被用作两家公司,包括麻省理工学院的创业公司nuTonomy, begin adverse weather testing of their AVs in the coming months. {#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
,在未来几个月开始对他们的AV进行恶劣天气测试。 {#文档内部-GUID-021e4442-7fff-部43ac-85c0-55132eeea634}

"We do not have [AV] sensors that can function properly in heavy rain and flood conditions yet," says senior scientist
"我们还没有能够在大雨和洪水条件下正常运行的[AV]传感器,"资深科学家说Niels de Boer, who runs CETRAN. All AV companies have to test their vehicles at the center before being allowed onto public roads. So far, most have prioritized functionality and safety over adverse weather testing, he says.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

The tropics, where sudden downpours of heavy rain frequently lead to flash floods, present special challenges for AVs. "Detecting standing water when it floods is difficult," says de Boer. "And even if you can detect the water, you don't know how deep it is."{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
热带突然倾盆大雨经常导致山洪暴发,对AVs提出了特殊的挑战。 "在洪水泛滥时检测积水很困难,"德波尔说。 "即使你能检测到水,你也不知道它有多深。"{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

When it rains, water droplets can absorb laser beams and radio waves, produced by lidars and radars respectively, and cause signal attenuation. Or the droplets may reflect these waves and wrongly register them as an obstacle in the vehicle's path, says engineer
下雨时,水滴会分别吸收激光雷达和雷达产生的激光束和无线电波,并导致信号衰减。工程师说,或者液滴可以反射这些波浪并错误地将它们记录为车辆路径中的障碍物Gil Jr Opina, who works on developing
,谁致力于发展autonomous electric buses and other vehicles at Singapore's Nanyang Technological University (NTU).

Rain can also distort the images collected by a camera and "generate atmospheric veiling effects similar to mist or fog," adds roboticist
雨也可能扭曲相机收集的图像,并"产生类似于雾或雾的大气遮蔽效果,"机器人专家补充道Daniela Rus from MIT who is working on the
来自麻省理工学院的工作人员Singapore-MIT Alliance for Research and Technology's fleet of self-driving cars and golf buggies. "All these degradations make it difficult to detect static and dynamic obstacles, resulting in poor localization and navigation."{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
自驾车和高尔夫球车的车队。 "所有这些降级使得难以发现静态和动态障碍,导致本地化和导航不良。"{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

To overcome these challenges, developers often seek solutions in software. When creating reference maps to help vehicles navigate, Rus and her team select "permanent or long-term features for localization that are robust to the changes in weather conditions." These include tall buildings, traffic poles, and tree trunks. "If it's a tall building, even if the rain obstructs a few data points, you can still get information from other points on the building," she says.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
为了克服这些挑战,开发人员经常寻求软件解决方案。在创建参考地图以帮助车辆导航时,Rus和她的团队选择"针对天气状况变化而强大的本地化的永久或长期功能"。这些包括高层建筑,交通杆和树干。 "如果它是一座高楼,即使下雨阻碍了一些数据点,你仍然可以从建筑物的其他地方获取信息,"她说。{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634 }

To correct for poor camera vision during heavy rain, Rus's team applies de-raining and de-hazing filters, trained using deep learning techniques, to the live video stream. Meanwhile, Opina and the NTU team extract information collected by the vehicle's various sensors, use machine learning to correct for any poor signals obtained, and then adjust the algorithms that control the vehicle's behavior. In response, the AV may slow down or alter its data collection rate.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634} | "We do not have [AV] sensors that can function properly in heavy rain and flood conditions yet." ---Niels de Boer, CETRAN
为了纠正大雨期间不良的摄像机视觉,Rus的团队将使用深度学习技术训练的除雾和去雾滤波器应用于实时视频流。同时,Opina和NTU团队提取车辆各种传感器收集的信息,使用机器学习来校正所获得的任何不良信号,然后调整控制车辆行为的算法。作为回应,AV可能会减慢或改变其数据收集率。{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634} | "我们还没有能够在大雨和洪水条件下正常运行的[AV]传感器。" --- CETRAN的Niels de Boer

To further develop a comprehensive testing program for AVs in all types of terrible weather, Singapore's CETRAN wants to collaborate with other AV test centers overseas such as The American Center for Mobility in Michigan, AstaZero AB in Sweden, and K-City in the Republic of Korea, says de Boer.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
为了进一步为各种恶劣天气的AV制定全面的测试计划,新加坡的CETRAN希望与海外的其他视听测试中心合作,如密歇根的美国移动中心,瑞典的AstaZero AB和共和国的K-City。 de Boer说,韩国。{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

To say that Singapore's government is pushing hard to develop the nation's AV sector would be an understatement. Earlier this year, the city state released
要说新加坡政府正在努力发展这个国家的AV部门将是轻描淡写的。今年早些时候,该州发布了该州national standards to guide the development of driverless vehicles---making it possibly the first country in the world to do so. In February, Singapore beat 18 countries, including the United States, to clinch second place in the
引导无人驾驶车辆的发展 - 使其成为世界上第一个这样做的国家。 2月,新加坡击败包括美国在内的18个国家,获得第二名Autonomous Vehicles (AV) Readiness Index [PDF] published by consulting firm KPMG International.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

"I think one aspect that makes Singapore unique is that it's really a government-initiated activity," says de Boer. Comparatively, large automobile companies and tech giants are driving the push for autonomous vehicles in other countries, he says. Think BMW in Germany, Volvo in Sweden, or Waymo in the United States.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

Instead of private cars, Singapore envisions autonomous shuttles, buses, taxis, and even
新加坡设法使用自动班车,公共汽车,出租车甚至是私人汽车,而不是私家车road cleaners. With 5.6 million people living in an area fewer than 725 square kilometers, or roughly two-thirds the size of New York City, Singapore is the
。人口560万,居住面积不到725平方公里,约为纽约市面积的三分之二,新加坡是third most densely populated country in the world.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

Transportation infrastructure, including roads and parking, occupies close to 20 percent of Singapore's total land area, says
交通基础设施,包括道路和停车场,占新加坡总土地面积的近20%Anshuman Tripathi, who leads AV research at the Energy Research Institute at NTU (
,谁在NTU能源研究所领导AV研究(ERI@N). Plus there are now "more and more rush hours" as the number of journeys made by residents has increased by 15 to 18 percent in recent years.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

Public transport AVs, if introduced, could support a "car-lite" society and ease congestion. They would also bring the country one step closer to its vision of becoming a so-called
公共交通AV如果被引入,可以支持"汽车精简"社会并缓解拥堵。他们还将使该国更接近其成为所谓的愿景Smart Nation, a goal announced five years ago.{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}

In the coming months, AV trials in Singapore will begin to move away from university campuses and other controlled environments, into residential areas. If all goes well, Singaporean commuters could see the first AVs for public transportation
在接下来的几个月里,新加坡的AV试验将开始从大学校园和其他受控环境转移到住宅区。如果一切顺利,新加坡通勤者可以看到第一批公共交通AVdeployed in three small towns by 2022. Says de Boer, "We're pushing very, very hard to achieve that goal."{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}
de Boer说:"我们非常非常努力地实现这一目标。"{#docs-internal-guid-021e4442-7fff-43ac-85c0-55132eeea634}