What is Lane Departure Warning System in Cars & How to Use?

source:cldnry

Accidents or critical conditions can occur if a vehicle strays out of its lane. In fact, there are news and instances that you might witness now and then where major accidents occur just because a vehicle was out of its lane. This can happen due to careless or rash driving or just a simple mistake. 

There have been significant technological improvements in the automobile sector to assist humans with a better and safer driving experience. Lane Departure Warning System is one such innovation.

Lane departure warning systems aim to improve your safety by minimising accidents caused by accidentally drifting out of your allotted lane. This sophisticated device alerts you when any of your tyres make contact with the lane markers by actively determining the boundaries of your lane. 

This signal is often in the form of a visible flashing indication and/or an auditory alarm emerging from the relevant side. In more sophisticated configurations, you may also notice a mild vibration in the steering wheel or driver's seat, offering an extra tactile indication to keep you alert and in charge

The lane departure system recognises lane markings using a camera near the rearview mirror, requiring visible paint stripes on both sides of the car for optimal performance. It is unable to recognise restrictions. The working process is as follows:

• When the system detects that your vehicle is approaching the left or right lane lines without using the turn signal, it will activate a warning light, vibration, and/or sound as an alarm.

• In addition to the camera, it has a steering input help capability. This clever mechanism gently adjusts the steering wheel to ensure your car stays in the assigned lane's confines. Lane Keeping Assist successfully maintains appropriate alignment by softly guiding the car in the opposite direction of the lane boundary. 

• Certain systems even intensify steering response as your vehicle approaches lane markers, providing a progressively stronger tug on the steering wheel.

Lane departure warning and lane-keeping assist systems can be activated manually or automatically when a vehicle starts. There is a dedicated button and an indicator light that shines to show the system's active state.

While your vehicle is travelling on straight or gently curved roads with the turn signals turned off, the lane departure warning system continually monitors for lane markers. Notably, this device does not issue alerts when you engage the turn signals or do quick steering movements.

Most lane departure warning and lane-keeping assist systems operate admirably on highways. It's worth noting that some systems only work at speeds more than 35 mph.

With technological advancements, there have come variations in lane warning departure systems. Here are the three major forms of lane departure warning systems: 

Lane Departure Assist

The lane departure warning system is strictly for preventive purposes. It informs you when your car approaches, strays close or passes over lane lines. You are obligated as a driver to respond quickly by directing the car back to the centre of the lane. 

This approach depends on lane marker availability and may be ineffective on roads without such markings.

Lane Centring Assist

A proactive lane-centring assist system is the most recent and sophisticated solution available. This wonderful function keeps the car continuously centred inside its current lane. 

To work properly, the system must detect that the driver's hands gently rest on the steering wheel and that the curves along the route are not too severe. Some may consider it to be the first building element of what is also known as self-driving technology when equipped with both lane centring aid and adaptive cruise control.

Lane Keep Assist

This device assists when the vehicle deviates from the desired lane. In such cases, the automobile automatically changes its steering to drive clear of the lane marking. It is the driver's obligation to return the vehicle to the centre of the lane. 

A lane-keeping system, lane assist, side assist (Audi), lane departure alarm with steering aid (Toyota), or lane departure prevention (LDP, which may also include lane centring assist in some circumstances) are all names for this technology.

You should pay attention to the lane departure warning system and do the needful when necessary. The alert style or option varies from one manufacturer or model to another. Here are some of the most common lane departure warning options:

Audio feedback

Certain automobiles generate warning beeps when their vehicle crosses a solid or dashed lane barrier and then stop producing sound once the vehicle is no longer close to the lane's edge.

Somevehicles allow you to change the loudness of the warning sound. However, it is crucial to remember that passengers who detest auditory notifications will still be irritated, albeit to a lesser extent, even with quieter beeping tones.

Haptic feedback

Alternative automobiles employ steering wheel or seat cushion vibrations distinct from those experienced on uneven or gravelly roads, as well as those caused by the activation of anti-lock brakes. The feedback through seat cushion vibrations can be targeted to either the left or right side, guiding the driver's attention to the specific side of the vehicle that requires corrective action.

Minimum speed to engage

The lane departure warning system becomes operational at approximately 50-65 kph speeds. It is not designed for low-speed or stop-and-go driving, primarily due to limitations in the camera's visibility of an adequate portion of the lane markings.

Visual feedback

This is an additional warning. When a car veers outside its lane, it emits a visual signal. Typically, this consists of a portrayal of paired striped lane lines, often accompanied by an automobile sign in the centre. 

These indicators are usually yellow and green when LDW is active and working properly. If the vehicle leaves the lane, the markers on the other side of the lane turn red or begin to flash.

Early versus late warnings

In certain vehicles, drivers can select when the alert and/or lane correction system engages concerning the car's position relative to the lane marking. They can choose whether the alert occurs before reaching the lane marking, precisely on the lane marking, or after crossing over it.

Force to overcome LKA/LCA

Equipped with lane keep assist and lane centring assist, the vehicle automatically guides itself back into the lane. However, it is always possible for the driver to override the automatic steering by turning the wheel with greater force than the car applies. 

Usually, this aspect is not customisable and is determined by the car's built-in settings.

Road departure mitigation

Certain lane departure warning (LDW) systems intend to differentiate the edge of the highway as a particularly hazardous scenario instead of drifting into an adjacent lane. These technologies can apply a corrective force to direct the vehicle back into the road if the conditions warrant it. 

Acura was a pioneer in the introduction of road departure mitigation technologies.

If there is a camera in the windshield facing forward, there are multiple functions it can serve for the car other than lane departure assist:

Pedestrian detection

Even at speeds of up to 20 mph, the camera and computers in the car can recognise pedestrians in your path. The system conducts safe braking techniques to avoid potential crashes in such cases. 

Similarly, if you fail to brake for automobiles ahead, the system intervenes by applying the brakes correctly. Some automobiles use radar technology designed for city braking.

Forward collision warning

The system compares the speed with which the silhouette of an automobile expands inside its range of vision by monitoring an object's proximity and closing speed using a single camera (rather than stereo cameras).

Windshield wiper control

When the system detects a blurry image, the algorithm infers that it may be due to raindrops hitting the windshield. In such cases, if the wipers are set to intermittent mode, the system automatically adjusts the delay between wiper swipes to provide more frequent clearing of the rain.

Sign recognition

By utilising a video feed and employing pattern and optical character recognition algorithms, certain vehicles can identify and interpret various types of signage. This includes determining the posted speed limit, temporary construction speed limits, or alerts about accidents or fog from overhead signs.

Adaptive cruise control

Subaru Eyesight uses a pair of stereo cameras positioned approximately one foot apart on either side of the rearview mirror. These cameras offer sufficient accuracy to replace radar in an adaptive cruise control (ACC) system, which maintains a safe distance from the vehicle ahead. While the stereo camera-based ACC range may not be as extensive as radar-based systems, this is typically not a concern when driving at legal highway speeds.

Traffic light recognition

If you aren't paying attention, a colour camera in your windscreen may identify when the traffic light turns green. This capability becomes much more valuable when connected with a telematics system since it offers information about forthcoming traffic light phases, such as the transition from green to yellow to red or red to green. If it judges that you will not be able to reach the next traffic light before it turns red, the car may encourage you to slow down to save fuel.

Lane departure warning is less effective in bad weather, such as rain or snow. It deactivates and alerts the driver when vision is significantly impeded. Other limitations are as follows:

• It cannot operate when the road is snow-laden and there are no lane markers. 

• When approaching highway exits with deviating lane markings, the system relies on the existing lane marking and scans the road ahead to discern where the right-side market returns. 

• False alarms may occur on rare occasions when the system detects lane drifting while the car remains correctly centred. 

• Lane departure warning (LDW) is less effective when markings are worn out or replaced with raised dots rather than clean 20-foot painted lines. 

However, it is worth noting that the system's performance has greatly improved during the last five years.

To improve the operation of Lane Departure Warning Systems and other machine vision systems, an active programme to repaint road surface markings before they fade would be beneficial. Such a programme would be advantageous not just to drivers with ordinary vision but also to all motorists, especially in wet weather.