Basic Lane departure warning systems, What are they and how do they work?

Basic lane departure warning systems. What are they and how do they work?

A basic lane departure warning makes use of a single camera. The camera plus the processing software to run it will cost, at most, only a couple hundred dollars. I have seen a few available on amazon for less than $100. You can see the results of an amazon search for lane departure warning systems here. These are only basic models.

The software continuously monitors how close you are to the roads surface markings. If you veer to closely towards either side of the lane, it will alert you with a sound. However, it will only beep if your turn signal isn't on. Advances in more recent ( and obviously more expensive) models will automatically adjust your course if you don't take action within a few seconds. And now an even higher level of system that will automatically keep your car centered on the road. These are subtle corrections and you, as the driver, can always override the car and turn the wheel manually.

How the basic basic lane departure system works: a windshield camera that tracks lane markings on the road.

The most common lane departure warning system is a camera mounted at the top of the windshield (inside the car), often it will be mounted to the rear view mirror. It captures a continuous moving view of the road ahead. This image is digitized and then checked for straight or dashed lines — the lane markings on every major road. Obviously, as the driver, you’re supposed to keep the car centered between the two lines. As the car drifts side to side and approaches or reaches one of these lane markings, the driver will get a warning: a visual alert plus either an audible tone, a vibration in the steering wheel, or a vibration in the seat. If the turn signal is on, the car assumes the driver is intentionally trying to cross over the line, and there will be no alert. That is all the lane departure warning system does.

Then there’s the more advanced lane keep assistant system. The camera performs the same function but when the car reaches the lane marking, the car will automatically move itself away from the marker. Depending on the model, this steering change can be done by braking the opposite front wheel and the car will shift  back into the lane or the car can also move you back by slightly turning the steering wheel. In all cases and models, the driver can easily overide the system’s intentions by turning the wheel. There are also models that use a set of lasers or infrared sensors. However, these are rarely as cameras are much cheaper and just as effective.

The lane departure warning system is just one part of the advanced driver assistance system (ADAS) being created by companies such as Mobileye, Delphi Automotive Systems, Robert Bosch GmbH, and TRW Automotive Holdings Corp. Some of the many upcoming features will include adaptive cruise control that paces you against the car in front (keeping a consistent distance), lane departure warning or lane keep assistance watching ahead and to the side, blind spot detection watching for cars coming up in adjacent lanes, and rear parking sonar and a camera behind (sometimes on all four sides) watching behind when you’re backing up and pedestrian and motorcycle detection around the car. Lane departure warning/lane keep assist is so good now, the best systems could keep you centered in your lane for miles. It is almost (but not quite) a self-driving car at that point but be warned that all of them will stop working after just a few seconds if they detect no hands on the steering wheel.

In upcoming posts, I will explore in more detail each of these many exciting new features in an advanced driver assistance system (ADAS).