How Self-Driving Cars Work

self-driving and autonomous vehicle 自动驾驶和自动驾驶的车辆目前是在汽车电气化之后最明确的一个方向了。本篇文章来自UDACITY 优达城的自动驾驶基础讲解，通过这个文章你会大概明白自动驾驶。希望能引发你想过思考，同时我尽力翻译此文，想学习汽车英语的也可以看看。希望本文能开一个头，我也尽量持续分享和共同学习自动驾驶相关知识。

how do self-driving cars work?自动驾驶到底如何工作？

Self-driving cars have five core components自动驾驶五个重要部分:

Computer Vision计算机视觉

Sensor Fusion传感器融合

Localization定位

Path Planning路径规划

Control车辆控制

计算机视觉就是使用摄像头看路，人类仅仅用眼睛和脑袋去驾驶车辆就已经证明了视觉的力量，对于自动驾驶车辆，我们使用摄像头图片去寻找路线去追踪路面上其他车辆。

Computer visionis how we use cameras to see the road. Humans demonstrate the power of vision by handling a car with basically just two eyes and a brain. For a self-driving car, we can use camera images to find lane lines, or track other vehicles on the road.

传感器融合就是我们如何整合传感器数据，像雷达和激光和摄像头数据一起构建一个对车辆周边环境完整全面的理解，像摄像头一样好，这有像其他传感器擅长距离和速度的测量，以及其他传感器在不好的天气下能更好的工作，利用整合所有传感器数据，我们能得到一个丰富理解的世界。

Sensor fusionis how we integrate data from other sensors, like radar and lasers—together with camera data—to build a comprehensive understanding of the vehicle’s environment. As good as cameras are, there are certain measurements — like distance or velocity — at which other sensors excel, and other sensors can work better in adverse weather, too. By combining all of our sensor data, we get a richer understanding of the world.

车辆定位就是我们如何能够弄清楚我们在这个世界上的位置，在我们理解好了周边环境我们下一步行动。我们每个人的手机都有GPS，所以好像我们已经无时无刻都知道自己位置了，但是实际上GPS的精度只有1-2米，你想象下1-2米有多大，如果一台汽车位置误差1-2米，你想象下车可能脱离车道撞上其他东西了，所以我们需要更复杂的算法让我们在1-2厘米之内精准定位。

Localizationis how we figure out where we are in the world, which is the next step after we understand what the world looks like. We all have cellphones with GPS, so it might seem like we know where we are all the time already. But in fact, GPS is only accurate to within about 1–2 meters. Think about how big 1–2 meters is! If a car were wrong by 1–2 meters, it could be off on the sidewalk hitting things. So we have much more sophisticated mathematical algorithms that help the vehicle localize itself to within 1–2 centimeters.

路径规划是车辆理解了周边环境，并且定位了自己之后的下一步，在路径规划这个期间，我们在地图中绘制路径来达到我们想要达到的地方，首先我们需要预测周边其他车辆的行动，然后决定我们对这些车辆的响应行为，最后我们规划规定或者路径去安全舒适实行行为。

Path planningis the next step, once we know what the world looks like, and where in it we are. In the path planning phase, we chart a trajectory through the world to get where we want to go. First, we predict what the other vehicles around us will do. Then we decide which maneuver we want to take in response to those vehicles. Finally, we build a trajectory, or path, to execute that maneuver safely and comfortably.

车辆控制是这个环节里面最后一环，一旦我们获取路径从我们的路线规划区域，为了跟随路径我们需要控制转向以及油门刹车。很多时候你很清楚知道你要跟着哪条路，但实际跟随这条路需要一些努力，如果你在高速上做过急转弯你就知道这有多么棘手。赛车手在这方面有惊人的表现，我们相信自动驾驶电脑也在变得越来越好。

Controlis the final step in the pipeline. Once we have the trajectory from our path planning block, the vehicle needs to turn the steering wheel and hit the throttle or the brake, in order to follow that trajectory. If you’ve ever tried to execute a hard turn at a high speed, you know this can get tricky! Sometimes you have an idea of the path you want the car to follow, but actually getting the car to follow that path requires effort. Race car drivers are phenomenal at this, and computers are getting pretty good at it, too!

以上就是自动驾驶五个重要的部分，希望期待这项技术的人有个大概的了解，也希望汽车工程师们对自己参与为了这个事业当中的有所了解，自动驾驶当前是比较热门的汽车知识，多多包涵英语翻译，欢迎关注此公众号我希望能持续分享和共同学习自动驾驶相关知识。