Lane Detection System: What kind of sorcery is this?!


Reposted because I forgot to tag the title.

Ok, I’m going to jump right into this. My husband and I rented a car to make our family vacation trip from Texas to Florida. We were given a newer Toyota Camry, as we requested a car of similar size to our car, which happens to be a 2001 Toyota Camry. My mind was just blown by this car. My husband veered off the road just slightly, and an alarm started going off in the car. I am in my 30s with 2 teenagers, so I thought nothing could surprise me. I was wrong. As soon as the alarm went off, I jumped in my seat in excitement and asked if it was what I thought it was. We have now been playing with this system to see how it works. I had to pick my jaw up off of my lap because HOW DOES IT KNOW??!!?? When there is a slight bend in he road, we don’t use a blinker, but we turn the wheel ever so slightly, and it doesn’t go off. However, if we’re in a straight lane and we turn the wheel so the car moves into the next lane a little or into the shoulder, we get the alarm. It doesn’t come on when we use the blinker, and I understand how that would work, but I can’t figure this out, and I don’t understand any materials I’ve found on it, so someone please, ELI5!

In: Technology

The car has a camera and a computer. The camera takes a picture and the computer combs through it and rates each part the image looking for lines. If it’s pretty sure that something is a line, it gives it a high score. If it isn’t sure, it gives it a lower score. When the computer is done, it has a pretty good idea where the lane markings are, because compared to the rest of the road, other cars on the road, trees and sky, the lane markings will truly stand out as the only pure lines in the image. And once you know where those lines are, it’s easy to tell whether the car is crossing them.

I think this site explains it really well, especially since there are a few different types of warnings/indications and systems:

But basically, there is a camera that is facing the road in front of the car. It is usually installed high up in the windshield. The camera detects any lane markings ahead and then can tell if the car is staying within those markings or if it is veering off course.

The technology relies on clearly marked roads so if you’re on a dirt road or on a highway where the lane markings have been faded or stripped down it might not work that well.

And there are different versions of the system – some of them resist you changing lanes without putting the turn signal on first, for instance, and others just give you a warning that you’re going out of the lane.

There’s a camera in the top center behind the windshield. A software analyzes the videostream to detect lane markings and depending on the car also other things, such as pedestrians or traffic signs.

Some systems are better and some are worse. I’ve seen cars that can detect lane markings even in the worst conditions, while others already fail when the markings are worn out. In the end though, the system is usually as good as the software is.

Some cars use the lane system to also automatically steer and keep the car in the center of the lane. Also, a lot of cars combine the system with an adaptive cruise control that can follow the car in front of you and adjusts the speed automatically to follow the traffic. That system can either also use a camera, or radars that are mounted somewhere in the front of the car.

In very advanced systems, cars can also do automatic lane changes and fancy stuff like that.

Not an actual answer due to plenty of answers already, but take into consideration that your car has to process the Imagines. Over. And over. And over again, and do so in a timely fashion to alert you on time. Which is a fairly basic thought. But keep in mind. Your car likely has more computer power than the world did in 1990.