Yahoo Autos Lane-keeping assist and lane departure warning: How they work and what's the difference
One of the most fundamental advanced safety systems — part of what many in the automotive industry call Advance Driver Assistance Systems — in a modern car is lane-keeping assist, or lane-keep assist. It's a simple idea, but it's anything but simple in execution. Accordingly, there are many variations of lane-keeping systems across vehicle brands.
What is lane-keeping assist?
Lane-keeping assist is exactly what it sounds like: an active system that helps the driver keep their car in the lane of travel.
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How does lane-keeping assist work?
Using cameras looking ahead at the road surface, the lane-keeping assist (LKA) system monitors for road markings, including the stripes along the sides of the road as well as the lane dividing markers, in order to keep the vehicle centered in its lane. Each system requires its own level of confidence in the lane markings, but once the threshold is met, the system will typically announce its availability through an icon on the vehicle's instrument panel. The system can then be activated by the driver, often with a button on the steering wheel.
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If the lane markings continue to meet the system's threshold for validity, it will continue to keep the vehicle in the lane of travel until the driver deactivates the system either manually or by using the steering wheel, or until it no longer has sufficient confidence in the position of the road markings.
In addition to the computerized camera system monitoring the road markings to determine where the lane is and where it's going, LKA also requires the vehicle be able to alter its path, either through the use of the steering system or by braking along one side of the car or the other. Systems that use the steering are typically more responsive and capable of dealing with more road curvature than brake-based LKA systems.
What lane-keeping assist doesn't do
As simple as the lane-keeping assist system's mission sounds — there's not much that's more basic to driving a car than staying in the proper lane — making that system robust and reliable in the real world presents a serious challenge. Faint lane markers, temporary construction or roadworks, inclement weather, road debris, and other conditions or factors can make it impossible for even the best lane-keeping systems to function. That means it's always incumbent upon the driver to maintain attention and control of the vehicle.
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