Lane Departure Warning

The Mobileye® lane departure warning application has been launched in multiple production platforms through 2007 and 2008 with GM, BMW and Volvo. Mobileye's lane departure and vehicle detection technologies are also included in Delphi's Advanced Collision Mitigation Systems which includes Delphi's Forewarn® Smart Cruise Control with Stop and Go, Forward Collision Warning and Lane Departure Warning. View related press releases on Delphi's collision mitigation system, Mobileye's LDW technology in GM's 2008 Cadillac STS and Buick Lucerne Sedan, BMW's advanced lane departure warning and Volvo Car's new lane departure warning system.

View LDW Video

 View News Broadcast, Embedded 'Alert System' Helps Drivers Avoid Accidents, Dr. Dobb's Portal, December 2007

Lane Departure Warning (LDW) is available either as a standalone feature or as part of a wider functions bundle, such as LDW with Intelligent Highbeam Control and Traffic Sign Recognition on the BMW 7 Series or as a radar vision fusion system on the Volvo vehicles. From 2010 onwards Mobileye will launch LDW as part of wider functions bundles, such as LDW with Forward Collision Warning, Intelligent Highbeam Control, Traffic Sign Recognition and fusion to radar, for multiple other global vehicle makers on multiple vehicle platforms.

Mobileye uses Lane Marking Detection and road geometry calculations to provide the driver with various functions such as Lane Departure Warning and Lane Keeping Support, which also uses a fusion to the vehicle steering system. Lane Departure Warning gives the driver audio and visual alerts in case of an unintentional lane departure, such as drifting out of lane or when not using the turn signals, whilst Lane Keeping Support will interact with the steering to provide a light feedback to alert the driver. The systems function in all light and weather conditions, though can be affected by extreme conditions, and detect all lane marking and road edge types.

Lane Departure Warning (LDW) / Lane Detection Algorithm (LDA)
The LDA recognises the lane markings and road edges and estimates the position of the car within the lane. The LDW module uses this information on the basis of a Time to Lane Crossing calculation to provide a warning to the driver in case of unintentional lane departure. The warning mechanism can be tuned for sensitivity – for example, the system can warn only when the vehicle is actually crossing the lane marking or it can give an early warning. The warning can be adapted to the type of road – for example it could provide the driver with more slack in case of narrow roads or allow the driver to “cut” curves. In Lane Keeping Support (LKaS) the LDA is fused to the steering system, usually Electrically powered Steering systems, to provide a light haptic feedback (torque input) to the steering wheel to warn the driver of the situation.

Given that lane markings are visible and that their detection is not hindered by the presence of clutter, shadows, rain, snow or any other disturbance on the road, the LDA recognises the majority of white and yellow lane markings worldwide and the Mobileye system is over 99% available (as tested by vehicle makers in series programs)
Various lane marking types, such as solid, dashed, Bott’s dots and double lane markings have been validated successfully and brought into production.  Additionally the LDA recognises unmarked road edges such as the grass or gravel road edge. Additional information about the next lane is provided in order to aid the warning strategy and fine-tune it according to the OEM requirements. Moreover an approval mechanism for better separation of ambiguous lane marks, double lane marks, triple lane marks etc has been developed as well as fine tuning of the system to correctly react to the variability that exists in various countries. The approval mechanism can also make use of colour information (e.g. yellow lane marks) for better separation.

The LDA has been extensively tested in series production programs in Europe, North America, South Africa, the Middle East and Asia, and has been validated globally on multiple continents and in a wide catalogue of scenarios, including bright sun and inclement weather.  In construction areas, where there are multiple overlaid markings, the system becomes unavailable. Lane markings of different colours (ie Korean blue markings) may need special attention though preliminary testing has shown a favourable response.

Mobileye is currently working on a rear facing LDA using the existing rear facing cameras already in production for reversing applications. This enhances LDW capability in more challenging scenarios, such as when entering a tunnel or assisting when for example the sun blinds front camera, reflections on road due to tar seams etc) and will improve overall system performance.

The above video clip is recorded from a Mobileye real-time system, illustrates the lane following by graphically overlaying the lane tangents (green lines) - accounting for position and slope - and the road skeleton (blue line) accounting for the curvature estimation. The lateral distance from the wheels to the respective lane marks are displayed in the respective right and left corners and the curvature (as inverse radius of curvature) is displayed in the center bottom area.