How do Self-Driving Cars Work in the Snow?

Last Updated on October 8, 2019 by themechanic

You’ve probably heard a lot about self-driving cars in the news lately. Big tech companies like Uber and Google are currently experimenting with self-driving cars and prototypes. Their vision is to have a world where cars can drive people around without the people having to steer or control anything. The GPS will basically guide the car to the destination point. Sounds cool, right?

However, what happens if self-driving cars get stuck in rough terrain? Do the computers in these self-driving vehicles account for things like snowy or icy roads? Self-driving cars are still in the early stages of knowing how to deal with such road conditions. But there are technological innovations currently being done right now to address them.

First, let’s examine why snow interferes with the functionality of self-driving cars. They contain three pieces of technology which give them their autonomous nature: cameras, sensors, and a spinning laser. The sensors and cameras allow these vehicles to notice their surroundings. The spinning laser helps track whether objects or people are close to the vehicle. But if snow is falling from the sky, the laser will treat snowflakes as objects near the vehicle.

The Solution

So, how do self-driving cars work around this? Well, they rely heavily on their internal maps and 3D maps of the surrounding environment. The maps help the vehicle know where the lanes are located on the road if they are completely covered with snow. Sometimes it is hard for people to drive on snowy roads because they cannot see the lanes. But the mapping technology of these vehicles allows the computer to know where the lanes are automatically.

On the downside, this technology only works if snowflakes are not actively falling from the sky. If you have roads already covered with snow or rain, then self-driving vehicles should be okay to navigate on them. The problem is when the precipitation is coming down at the same time. Engineers are trying to figure out a way for the lasers to tell the difference between snowflakes and actual objects on the ground.

About the Spinning Laser

The credit for the spinning laser technology can be attributed to Uber. The name they have given this laser is LIDAR. It uses laser pings to detect nearby objects on the road. That, in conjunction with the mapping technology, allows the vehicle to travel on snowy roads just fine.

Here is how the LIDAR technology works:

A laser light pulse is emitted from the vehicle’s scanner. If the laser light pulse finds an object, the pulse is reflected off the object and back onto the receiver of the scanner. The length of time between the pulse leaving the scanner and the pulse reaching the scanner is then measured. Based on this measurement, the computer can calculate the distance between the vehicle and the object. These laser light pulses continue to be emitted at about 1000 times per second.

So, they don’t miss a thing when it comes to avoiding objects around the vehicle. The scanners are constantly rotating at 360 degrees, so they detect any objects around the entire circumference of the vehicle. Although, some self-driving vehicles only use solid state lidars which rotate at no more than 120 degrees.

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Overall, self-driving cars are showing a lot of promise in the world. The technology has already advanced so much over the last 10 years. Even though navigating through active snowfall has not been mastered yet, it is only a matter of time before these technology engineers figure out a way to deal with it. As for now, self-driving cars are able to navigate on snow-covered roads, and that is already a breakthrough in itself.

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