Lane centering


In road-transport terminology, lane centering, also known as auto steer, is a mechanism designed to keep a car centered in the lane, relieving the driver of the task of steering. Lane centering is similar to lane departure warning, but rather than warn the driver, or bouncing the car away from the lane edge, it keeps the car centered in the lane. Together with adaptive cruise control, this feature may allow unassisted driving for some length of time.
In addition to passenger vehicles, semi trucks are expected to be fitted with this technology, starting with the Tesla Semi and other vendors in 2019.

History

The first commercially available lane centering systems were based on off-the-shelf systems created by Mobileye, such as Tesla Autopilot and [|Nissan ProPilot], although Tesla switched to an in-house design when Mobileye ended their partnership. A handful of companies like Bosch, Delphi, and Mobileye provide sensors, control units, and even algorithms to car makers, who then integrate and refine those systems.
While not directly attributable to lane centering, crash rates on the Tesla Model S and Model X equipped with the Mobileye system were reduced by almost 40% while Tesla Autopilot was in use.

Operation

The lane detection system used by the lane departure warning system uses image processing techniques to detect lane lines from real-time camera images fed from cameras mounted on the automobile. Examples of image processing techniques used include the Hough transform, Canny edge detector, Gabor filter and deep learning. A basic flowchart of how a lane detection algorithm works to produce lane departure warning is shown in the figures.

Limitations

Features that differentiate systems are how well they perform on turns, speed limitations and whether the system resumes from a stop.
Current lane centering systems rely on visible lane markings. They typically cannot decipher faded, missing, incorrect or overlapping lane markings. Markings covered in snow, or old lane markings left visible, can hinder the ability of the system. GM's Super Cruise only works on known freeways that have been previously mapped, as it uses a combination of these maps and a precise GNSS position provided by Trimble's RTX GNSS correction service to determine if Super Cruise can be enabled or not.
Most vehicles require the driver's hands to remain on the wheel, but GM's Super Cruise monitors the driver's eyes to ensure human attention to the road, and thus allows hands-free driving.

2018 Mobileye EyeQ4

claimed in 2018 that 11 automakers would incorporate their EyeQ4 chip that enables L2+ and L3 autonomous systems; this would collectively represent more than 50% of the auto industry. Level 2 automation is also known as "hands off": this system takes full control of the vehicle. Level 3 is also known as "eyes off": the driver can safely turn their attention away from driving, e.g. the driver can text or watch a movie.
In 2018, the average selling price for the EyeQ4 chip to auto makers was about $450 U.S. dollars.
Nissan uses the EyeQ4 chip for their hands-off ProPilot 2.0 system.

Sample of level 2 automated cars

Because all of these vehicles also have adaptive cruise control that can work in tandem with lane centering, they meet the SAE standard for level 2 automation. Adaptive cruise control and lane centering are often only available in more expensive trim levels rather than just the base trim. An example is the Hyundai Kona EV, which only has adaptive cruise control available on the "ultimate" edition.
Manufact-
urer		Sample of vehiclesBranding for lane
centering		Notes
Daimler AGFreightliner Cascadia big-rig
Actros		Lane Keep Assist
Active Drive Assist
Fiat-ChryslerMaserati brand
FordEdge Escape Explorer Focus Mach-EFord Co-Pilot360: Lane Centering
GMCT6Super CruiseOnly on approved freeways Uses eye tracking system, which does not require driver to hold steering wheel.
HondaInsight Odyssey PilotHonda Sensing: Lane keeping Assist SystemBetween 45 mph and 90 mph
HondaAcura MDXAcuraWatchOnly at higher speeds
HyundaiPalisade Kona EV Santa Fe ElantraLane Following AssistAlso called Lane Keeping Assist, available at 60 km/h or above.
KiaKia Niro EV Kia Telluride Stinger K900 ForteLane Following AssistSpeed 0 - 130 km/h, 81 mph
LincolnAviator Corsair NautilusLincoln Co-Pilot360: Lane Centering
MazdaLane TraceCan be activated at speeds above 60 km/h
MercedesA-ClassDriver Assistance Package
NissanLeaf, Rogue AltimaProPilot AssistUnder 31 mph, ProPilot lane centering will work when tracking another car in the lane.
SubaruForester, Outback, LegacySubaru EyesightDepth perception based on stereo cameras. One of the few systems here, besides Tesla, not based on Mobileye tech.
TeslaModel S, X and 3Autopilot, AutosteerWorks at all speeds other than at certain margins above posted speed limits. V10 improvement notes.
ToyotaCorolla Rav4 Highlander Lexus ESLane Tracing AssistPart of second generation Toyota Safety Sense
VW2020 AtlasTraffic Jam AssistOnly works below 37 mph
VWAudi A82019 Traffic Jam PilotLevel 3 Autonomy. Germany first. Not for U.S.A. in 2019. Top speed: 37.3 mph, 60 km/h
VWAudi A6 Porsche TaycanTour AssistTop speed 155 mph
VolvoXC40 XC60 XC90Pilot Assist II

Nissan ProPilot

Nissan ProPilot is based on Mobileye technology and assists with acceleration, steering and braking input under single lane highway driving conditions. ProPilot keeps the car centered in the lane and will deactivate below 31 mph if not tracking a car in front of it. Adaptive cruise control handles stop-and-go traffic if stopped for less than 4 seconds and helps maintain a set vehicle speed and maintain a safe distance between the vehicle ahead. ProPilot, which can follow curves, uses a forward-facing camera, forward-facing radar and other sensors. A traffic sign recognition system provides drivers with the most recent speed limit information detected by a camera on the windshield, in front of the rear-view mirror.
In a review by ExtremeTech, ProPilot worked well in 1,000 miles of testing and only on some twisty sections did it require driver intervention. During Euro NCAP 2018 testing, ProPilot failed some tests as did all other systems tested. Consumer Reports indicates that ProPilot is especially helpful in stop and go traffic.

Honda Sensing

Honda Sensing is a suite of advanced driver assistance features including Lane Keeping Assist System which helps keep the vehicle centered in a lane, by applying mild steering torque if the vehicle is deviating from the center of a detected lane with no turn-signal activation by the driver. Mild steering torque means the system will not work on tight turns; additionally, the system does not work at speeds below 45 mph. The Honda Sensing package also includes:
Quote from David Zuby, chief research officer at the American Insurance Institute for Highway Safety:
The report indicated that only the Tesla Model 3 stayed within the lane on all 18 trials.
Quote from the report:

News