Adaptive headlights differ from ordinary ones in that they direct light beams in that direction where wheels turn. Thanks to the “smart” headlights, the turn is fully visible even at the moment when the driver is just starting to turn the steering wheel. The headlights that literally “follow” the steering wheel turn used to be fantastic, but now this additional option is available for many cars.
The device and principles of adaptive headlights
The adaptive headlight system includes an on-board computer, sensors that respond to steering and other indicators of changes in vehicle motion. Among them: speed, position of the car relative to the vertical axis and even wipers. The latter affect the adaptive headlights as follows: when the wipers are activated, the lights lower and then return to the previous level.
For the first time, adaptive headlights for cornering lights appeared on the 1948 Citroen 2CV. The driver controlled the change in the direction of light horizontally using a mechanical lever in the cabin
The lights themselves are equipped with a stepping electric motor, which turns them in the right direction. At the same time, it works very precisely - the angle of rotation can be negligible, and it can also be different for the right and left headlights: when turning right, the right headlight turns to maximum (which is 15 degrees), while the angle of rotation of the left is half of this value. AFS uses exclusively bi-xenon lamps. And thanks to the fact that the systems are computerized, all of its actions are accurate and at the same time smooth: light rays with their movements will not distract the driver from the road.
An important feature of this system is that the headlights can be rotated not only horizontally, but also vertically. This function is especially useful when driving on hilly terrain - when climbing, the headlights are lowered so as not to blind the oncoming driver, but on the downhill, on the contrary, they are lifted, thus illuminating the next section of the road.
AFS has a connection with the exchange rate stability system - when EPS is triggered, the headlights stop responding to the steering wheel movement to avoid unnecessary manipulations during the chaotic torsion of the steering wheel. The system will reactivate if the driver turns the steering wheel a sufficiently large angle.
Mercedes-Benz offers owners of cars of the brand a control system not only dipped, but also high beam
Another useful feature of this system is that sensors can respond to the light of the headlights of an oncoming car when it approaches. In this situation, the electric motor drives the headlights and lowers them down a few degrees, thus preventing the driver from blinding in front. After the lights take their former position.
By the way, adaptive headlights lowered down work similarly to foglights: light is scattered half a meter from the surface of the roadway, without "snatching" individual drops from the air.
Differences between AFL and AFS
There are more sophisticated AFS systems, they have a different designation AFL. These are equipped with additional lights in the right and left headlights that work when the steering wheel is turned sharply. They work separately: if the driver sharply twists to the right, then the right additional light automatically turns on, illuminating the trajectory of the car, when turning left, accordingly, the left.
BMW, Toyota, Skoda and Opel have been installing AFS on their cars since 2003
Adaptive headlights can also work in several modes. The first will be especially useful for those who often find themselves on dark highways. He received such a name - trunk. In this mode, the lights shine powerfully and brightly, dropping down when approaching an oncoming car. The second mode is called suburban and is an analogue of the passing beam. AFS also has its own mode for the city - its feature is an expanded light spot. It is very effective for driving along poorly lit streets - the lanterns literally “snatch” curbs and sidewalks from the darkness, as well as inconspicuous pedestrians. Experts assess the adaptive headlight system as extremely effective: according to statistics, cars equipped with AFS or AFL get into accidents 40% less often than cars with standard headlights.
Despite the fact that this system is a relatively new development, experts continue to improve it. So, the appearance of adaptive “stops” is not ruled out - it is planned that they will warn the driver behind the driver not only about braking the car, but also about how hard the driver presses the brake pedal: if the driver applies emergency braking, the headlights will light up brighter.
In the near future, automotive optics may expect even greater changes. It is possible that instead of two lights, cars of the future will receive a light-emitting fiber-optic system, through which the on-board computers of oncoming cars will "communicate".
American and European automotive optics, differences, installation problems
This is the way human psychology works so that it’s natural for us to desire what we don’t have. Car enthusiasts are no exception to the general rule. One of the most common desires of the European part of motorists is to install headlights and taillights, made in the American style, Americans also occasionally have similar obsessive desires, only they want to get Europeanized optics.
In North America or Europe, some people replace the light optics of their cars mainly for aesthetic reasons. They just like the end result, what a car with a changed style of turn signals looks like. Indeed, perhaps with the replacement of the color of the turn signals, only the installation of other discs as a means of radically changing the style of the car can argue. A modification of the stylistics of the headlights can give incredible results in changing the appearance of cars, especially in some models.
It is worth noting that in Russia this problem is also quite acute, but the matter is more likely not related to style or design, just because of a number of objective technical reasons, the beam of illumination of American headlights on old cars and the light output of lamps is worse than that of European representatives, and since "American" in the past, a considerable amount was imported, then many, many thousands of motorists decide to replace the original headlights with European counterparts.
Moreover, European standards clearly regulate the shape of the light beam (the right side of the road is well lit, the signs and obstacles to the right are better identified with European headlights. The oncoming lane, on the contrary, is less lit, which makes it possible not to blind other drivers.) The headlights in the American version have an almost symmetrical area lighting, which does not give such an effect, but on the contrary, exacerbates the situation, the “oncoming” blinds, the curb is not illuminated enough. Plus, not everyone wants to show that their car is an American-backed one, they give it out to the red rear turn signals.
Headlights that meet the European standard are marked with the letter "E" in a circle with an additional digit, country code. American headlights are labeled DOT, Department Of Transportation, orSAE, Society of Automotive Engineers, which may serve as a pretext for refusing to undergo a technical inspection.
In view of the foregoing, we decided to take a short excursion into the history of the appearance of two diametrically opposite types of headlights and show in general terms what to look for when replacing optics using the example of both old cars and new models.
The manual applies only to cars that were produced in the same design for both the American and European markets.
Since the article will focus on the "American" and "European" headlight styles, we will deliberately not concern right-hand drive cars. There are more difficulties with them because, due to the technical features of these cars, their headlights and reflectors are designed in such a way as to direct a beam of light towards the left side of the road, that is, in our right-hand traffic, towards the oncoming traffic, which is expressly prohibited by the legislation of the Russian Federation and falls under list of malfunctions and conditions for prohibiting vehicle operation on roads.
On the Internet there are many examples of solving this problem on Japanese right-hand drive cars, from the banal rearrangement of headlights from the European counterpart to the sophisticated correction of the situation on their own.
So, let's start studying the issue. Let's start with a historical tour. How did it happen that in Europe and North America, different headlights began to be installed on cars?
Why do cars in Europe and the USA have different headlights?
Most of our readers are probably wondering why there are two types of headlights at the same time. The origins of the emergence of two standards must be sought in the 1940s, when the American authorities made an attempt to unify the new sealed headlights that appeared, in order to solve the problem of the optics turnover of the old formation and to exclude the appearance of non-standardized headlights of those times. The Americans had a rather strange approach. In order not to bother with unnecessary measurements for compliance with the standards of the new headlights, the government decided to develop one single type of seven-inch headlamps in a non-separable housing inside which only a reflector, reflector, and incandescent low and high beam were installed. Everything! No lamps of different powers and other benefits of optical civilization. The headlight ceased to shine? You go to the store and buy the same, new, whole.
It took more than 40 years to finally come to a new standard. By this time, the outlandish approach was outdated a hundred times and only thanks to pressure from automakers pushed into a narrow framework did the regulator make concessions by repealing the law in 1983. But time was lost and this echoes to this day, not all new models of the American "bottling" are able to surpass or at least compare in quality of lighting with their European counterparts. Even modern technologies and globalization cannot change the situation.
American standards are audited by the United States Department of Transportation (DOT) or SAE (Society of Automotive Engineers), while European vehicles use ECE approved components.
The main differences between European and American headlights
The main and main difference between European and American headlights, as you already understood from the text of the article, is not in the orange and red reflectors of the turn signals, they go much deeper and straight into the technical wilds. As we noted above, the main difference between the headlights of the Old and New Worlds is the amount of light falling on the oncoming traffic lane. According to the American DOT standard, it is much higher.
This phenomenon can be partially explained by historical prerequisites. In Europe, a fairly extensive network of two-lane narrow roads. Low light, plenty of turns, all this makes it extremely dangerous to use Americanized headlights on such roads. Conversely, wide, well-lit highways, laid in abundance over the vast expanses of the United States, can allow you to ride with an outdated light distribution system.
Another difference is that European fog lights must also have rear fog lights, this nuance also increases the difficulty of replacing optics.
In addition, another difference is the presence of a self-leveling system on European cars.
Since the creation of the car and its transition to the status of a full-fledged vehicle, the question arose about the possibility of round-the-clock use of the car. And this, in turn, required the availability of lighting.
The very first lights used kerosene, but they solved the lighting problem very poorly. Rather, kerosene lights simply signified a vehicle. The pilot and aircraft designer Louis Bleriot in 1896 proposed the use of acetylene lamps. Similar lamps by that time were used as locomotive floodlights. To obtain acetylene, a special tank was used, mounted on the footboard from the driver’s side, into which calcium carbide and water were poured. To turn on the headlights, the driver had to open the acetylene supply valve, open the headlights and light the burners built into them with a match.
Starting in the 1920s, electric lamps were used. Headlights with incandescent bulbs were spotlights that dazzled oncoming drivers. When driving with an oncoming car, the driver had to tilt the headlights down, using a special lever with a cable or hydraulic mechanism for these purposes. Another way to reduce glare was based on reducing the intensity of the glow by reducing the incandescent current of the lamps using a rheostat. But all these tricks distracted the driver, and did not give the opportunity to install the headlights after changing to the starting position.
On more expensive cars, individual headlights for dipped and main beam were installed. The power of such headlights was different: for the dipped beam was 30 watts, for the distant 50 watts. The beam angle of the dipped headlights was set to illuminate the road 15–20 meters ahead, while the far beam light was 40–60 meters. This allowed the driver to switch the headlights to the desired lighting mode much more convenient.
The power and range of the light was increased using the development of Ivan Petrovich Kulibin in the field of a parabolic reflector. Thus, a headlight having a parabolic reflector and lenses could illuminate several hundred meters.
In the future, manufacturers began to complicate the design of the lamps. Bosch in 1925 was the first to produce double-filament incandescent lamps, one of which was used for dipped beam, the other for high beam. Halogen lamps having the best characteristics and greater reliability fell into mass use. It also became possible to reduce the weight of the batteries due to the appearance in the cars of a generator that powered high-power electric bulbs and removed the problem of the need to recharge batteries at the stations.
Changes in lighting technology were accompanied by the introduction of new lighting rules. In 1957, asymmetric light was legalized in Europe, according to which the light from the driver shone closer than the light from the passenger side. This reduced the risk of blindness to the oncoming driver and increased safety.
Another direction of modernization of lighting equipment was to change the shape of the headlamp. If earlier all the headlights had a round profile, then starting in 1961 Citroën tried square headlights. This allowed us to improve the aerodynamics of the car, to increase the luminous flux due to the Hella retroreflector with an ellipsoid shape with two axes, where two pairs of rays from different foci were assembled into one collecting lens. And in 1986, three-axle headlights were installed on BMW cars.
Thanks to the computing power of modern computers, it became possible to calculate and manufacture headlights having almost any shape suitable at the request of the car designer.The complexity of the modern headlamp device lies in the many tricks of the headlight reflector, responsible for lighting a certain section of the road.