不会撞车的汽车梦想成真

    汽车即将发生碰撞时，汽车安全系统就能立刻察觉，同时启动刹车系统，收紧安全带，以减轻对乘客的伤害。现在，这类系统正升级换代，未来有望完全防止某些碰撞。

    2013款雷克萨斯（Lexus）LS460是丰田汽车（Toyota）豪华品牌的旗舰。它将于今年11月登陆美国市场，届时可选装“高级预防撞系统”（advanced pre-collision system）。当时速低于29英里时，这套系统会用雷达和光学传感器判断车辆是否会与前方的行人或物体相撞。如果司机分神、注意力不集中或受伤，它会取而代之，在碰撞发生之前迫使汽车停下，可能特别有助于避免造成行人伤亡。

    未来某一天，丰田的这一安全装置会安装在绝大多数车辆上。它标志着不断发展的自动驾驶技术迈出了新的步伐。很多人相信，这一技术进步必将在不远的将来催生出无人驾驶汽车。市场研究公司HIS的汽车行业分析师吕蓓卡•林德兰称：“这类系统表明，我们在无人驾驶汽车的发展上又取得了更大的进步。十年内我们就能看到首辆无人驾驶汽车的诞生。现在人们还不太能相信这一点。但是当年一样没人相信马会被汽车取代。”

    通用汽车（General Motors）、福特汽车（Ford Motor）、大众汽车（Volkswagen），还有绝大多数汽车厂商和供应商都在开发无人驾驶或所谓的自动驾驶所需的数字与机械系统。大众公司（VW）的奥迪品牌（Audi）已暗示，两年内，它就将在下一代A8旗舰车型上搭载一套系统，能让驾驶者在公路上处于低速的停停走走状态时开启“自动巡航”（automatic pilot）功能。在这一模式下，汽车能随着车流自动行驶、加速和刹车，同时避开周围的车辆。

    在帕洛阿尔托市（Palo Alto）的东部，靠近谷歌公司（Google）总部的一处大型停车场内，丰田的工程师和技术专家为媒体搭建了一条测试车道，用来展示其新型自动驾驶系统（而谷歌早就以其首创的自动驾驶汽车名噪一时了）。我也在受邀之列，得以驾着一辆搭载这一系统的LS460原型车，向一个由布制成、上面画着一辆车的障碍物驶去。

    当提速到约时速30英里后，我将车对准那个布质目标驶去。首先，仪表盘上出现了一个前方有障碍物的视觉警示标识。随后，车里响起了报警声。虽然有点紧张，但我还是踩着油门不放。车继续加速，碰撞似乎不可避免就要发生了，这时，车突然夺过控制权，随着一声尖锐的刹车声，车在距障碍物咫尺之遥的地方停了下来。

    坐在副驾驶座上陪同我的一位技术人员向我解释道，这套系统刹车的力量大约是普通驾驶者踩踏的两倍。另一套名为“驾驶者注意力监测系统”（Driver Attention Monitor System）的系统则通过摄像头观察驾驶者的脸部表情，判断驾驶者何时分神，司机较长时间没看路面或是打盹的话，系统随即会启动闪光报警，同时发出警报声。如果这些步骤都不奏效，自动驾驶系统就会自行刹车。

    尽管丰田在美国和日本的研发中心都在开发自动驾驶技术，但它对细节守口如瓶，不愿意透露完全自动化的汽车到底什么时候能够投入测试。谷歌的无人驾驶汽车项目用一辆改装的丰田普锐斯（Prius）已在公路上进行了超过10万公里的测试，除了一次保险杠轻度弯曲外，没有发生过任何事故。2011年，内华达州在全美率先修改了法律，允许无人驾驶汽车正式上路。谷歌则在今年3月获得首个批准，让一辆普锐斯上路。

    雷克萨斯的这款新LS还远谈不上能完全自动驾驶。但是，如果这套“高级预防撞系统” 能让车主们避免事故，他们可能会开始体会到这种技术的效果。

    译者：清远

    Automotive safety systems that sense when a vehicle is about to crash and initiate braking and tighten seatbelts to mitigate injury are evolving into systems that can prevent some collisions entirely.

    The 2013 Lexus LS460, Toyota's (TM) luxury flagship, begins arriving in the U.S. in November with an "advanced pre-collision system" available as an option. When driving at speeds below 29 miles per hour, the system uses radar and optical sensors to determine if a car is likely to collide with a pedestrian or object ahead. The Toyota system can override a distracted, inattentive or impaired driver and bring the car to a stop prior to impact. It could prove especially helpful to preventing pedestrian injuries and deaths.

    Toyota's safety device, which one day could be equipped on many if not all vehicles, marks yet another step in the continuous automation of driving, a process that many believe leads inevitably to driverless vehicles in the not too distant future. "These kind of systems represent more progress toward driverless cars," said Rebecca Lindland, an industry analyst for HIS automotive. "We could see the first driverless cars in ten years. People have trouble believing it. No one could believe that horses would give way to automobiles."

    General Motors (GM), Ford Motor (F), Volkswagen and indeed most automakers and automotive suppliers are working on digital-mechanical systems that are integral to driverless or so-called autonomous driving. In two years VW's Audi luxury division has hinted it will offer a system on its next-generation A8 flagship that allows a driver in low-speed stop-and-go freeway traffic to put the vehicle on "automatic pilot." In this mode the vehicle automatically speeds, accelerates and stops with the flow of traffic and avoids other vehicles around it.

    Toyota engineers and technicians set up a test course for journalists in a large parking lot in east Palo Alto, near Google (GOOG) headquarters, to demonstrate its new system. (Google has made headlines with it driverless car initiative.) I was among those invited to drive a prototype of the LS460 equipped with the system toward a cloth barrier depicting a graphic of a car.

    After accelerating to about 30 miles per hour, I was aiming the LS460 toward the cloth target. First, a visual warning of an obstacle ahead appeared on the dashboard. Then, a chime sounded. Still, somewhat nervously, I kept my foot on the accelerator. A collision seemed inevitable when suddenly the car took control and braked us to a screeching halt just short of the barrier.

    A technician accompanying me in the front-passenger seat explained that the braking force of the system was roughly twice what a normal driver could accomplish by stamping on the pedal. Another system called the Driver Attention Monitor System trains cameras on the driver's face and determines when a driver has become distracted, taken eyes off the road too long or has fallen asleep -- and flashes a warning and sounds a chime. If those steps don't work, the system can apply the brakes.

    Though Toyota is working on autonomous driving at research and development centers in the U.S. and Japan the automaker has been reluctant to release details of when a fully autonomous car might be ready for testing. Google's driverless car project has tested a modified Toyota Prius on public roads for over 100,000 miles without an incident beyond a minor fender-bender. In 2011 Nevada became the first state in the U.S. to modify its traffic laws to permit operation of a driverless car. Google was issued the first permit for a Prius in March of this year.

    Lexus's new LS is far from ready to drive entirely on its own. But its owners may begin to understand how the technology could work if the Advanced Pre-Collision System saves them from an accident.