Development trend of modern automobile lighting system

At present, the automotive lighting system is undergoing important changes. Not only HID and LED light sources are more widely used, but also the automotive lighting system is becoming increasingly intelligent. And the scope of intelligence is constantly expanding. Automobile manufacturers are attracting users with advantages such as safer, more environmentally friendly, more exquisite design and more fuel-efficient. At the same time, new car models must also comply with the latest regulations, which leads to the continuous application of new technologies.

Among the lamps of cars, except for the license plate lights, the main function is to provide road lighting for the driver. In certain cases, they can also serve as signals, such as flashing the headlights to alert the other party when overtaking. The external signal lights are set to facilitate other drivers to identify the outline of the car and judge the direction of the car. Among them, the turn signal lights and brake lights are extremely important signal lights, which are of great importance to car safety. In order to further improve safety, in recent years, cars have widely used auxiliary brake lights-high-position brake lights, which are placed at the rear windshield to attract the attention of others.

The automotive lighting system is one of the three major safety parts of a car and is the most important active safety device. For example, the headlight of a car is an important component to ensure the safe operation of the car. The longer the headlight's illumination distance is, the better the light distribution characteristics are, and the higher the safety performance of the car is. Since automotive lighting is a key component of driving safety, both external lighting and external signal lights are mandatory inspection items. In view of the important role of lighting in car driving safety, all countries have strict regulations. To change the traditional lighting method, we must first study the regulations. To this end, Europe has organized a working group with automobile manufacturers (such as BMW, Rover, Mercedes-Benz, Volkswagen/Audi, Ford, Volvo, Renault, Peugeot, Citroen), lighting system suppliers and lighting manufacturers to conduct research so that there can be greater freedom in lighting design, gradually move towards adaptive lighting, and propose new regulations.

Car manufacturers are using the advantages of safer, more environmentally friendly, more beautiful design and more fuel-efficient to attract users. At the same time, new car models must also comply with the latest regulations, which leads to the continuous application of new technologies.

At present, the automotive lighting system is undergoing important changes. Not only HID and LED light sources have been more widely used, but the automotive lighting system is also becoming increasingly intelligent, and the scope of intelligence is constantly expanding. For example, the headlights can even be transformed to any angle so that the driver can see remote corners, but this also depends on the speed of the car. In addition, the lighting system inside the car also has an important impact on the interior environment of the car, and design engineers are also working hard to make this system more integrated with the interior environment. With the development of automobile technology, car headlights are undergoing more and more changes. In modern cars, the detachable incandescent bulbs and incandescent vacuum headlights of the past have been eliminated one after another, and replaced by halogen headlights, which have swept the world in recent years and become the main force of car headlights in various countries. At present, many manufacturers have developed various samples for testing, and some intelligent headlights have been installed on the latest prototypes.

Active swivel headlights

We can expect to see advanced headlighting systems from Audi in the next few years, from top to bottom: Cornering lighting systems and responses to steering lock and speed inputs; headlights that swivel; and headlight beam shape that changes with surrounding conditions.

In fact, some Citroën models have already started using this type of rotating headlights a few years ago, but this technology has not been widely popular. But now this type of active rotating headlights is being mentioned again, and it will have better applications than before.

Audi's Advanced Front Lighting System (AFS) is expected to be used in cars. In fact, the most basic lighting system of this technology (corner lighting system) is already used in the Audi A8 luxury car and some other cars. But the systems mentioned are more interesting: they can illuminate the surrounding corners before the car even starts to turn.

In the Audi system, side lighting depends primarily on the steering angle, but it also depends on the speed of the car. For example, when the car is driving on the highway and in the city, the headlights automatically change the beam width, angle and range when the corresponding input signals enter the system (including GPS). Almost all luxury cars sold today are equipped with GPS navigation systems, so this system is very feasible, and the safety performance of the system is remarkable.

When the traditional low beam lamp turns with a radius of curvature of 190m, the lighting range provided by the traditional low beam lamp is only 30m, while this system can reach 55m. The active lighting system using HID lighting technology has been widely used in Mercedes cars. The independent microcontroller controls the motor to rotate the corresponding headlights by processing the real-time information from the steering angle and speed sensors. In addition, the traditional active headlights can be used to reduce the chance of dazzling the driver.

BMW Lighting Systems

BMW pixel lighting system, this is the technology that the German automaker started to study not long ago, this is the so-called "pixelheadlights" system, it uses 480,000 independently controlled microscopic pieces to replace the traditional emitter function. The shape of the headlight column formed by this method fully meets the driver's driving conditions, and at the same time does not produce dazzling high beam lighting. And it has a unique lighting effect when turning, in the city, on the highway and in bad weather. In addition, its auxiliary light can also illuminate road signs.

The BMW Pixel light headlight system can provide the driver with special prompts and warnings. For example, when turning left, the light beam will display the corresponding left turn arrow instruction information.

LED headlights and intelligent headlights

LED headlights: Among the Ford concept cars that will be shown at the North American International Auto Show, one will combine environmental protection technology and use solar energy as the power source of the lighting system. It will collect energy during the day when there is sunlight, store it, and provide lighting at night; while another concept car will use light-emitting diodes (LEDs) to replace traditional bulbs, because LEDs have the advantages of high brightness, short response time and long service life. In the past, LEDs were usually used in taillights, but this time Ford engineers cleverly applied this technology to car headlights. The 2007 Lincoln Aviator will also fully adopt this new lighting system. It can be foreseen that all Ford models may adopt this headlight lighting system in the future. Ford will become the first car manufacturer to put LEDs into headlight design and actually mass-produce them. In the new lighting system, in addition to using the AFS active steering lighting system, it also combines LED light sources. The main lights still use traditional halogen bulbs, which have high-brightness light sources but do not have the glare of HID. With the auxiliary lighting of LED, the vehicle can have all-round lighting capabilities.

Intelligent headlight system: Hella's bi-xenon headlights with integrated high-beam using high-voltage gas discharge have been mass-produced. On this basis, the company has newly developed dynamic cornering lights. Dynamic cornering lights are an important part of the intelligent headlight system. This new technology greatly improves driving safety and comfort. The characteristic of dynamic cornering lights is that the headlights can swing within ±150 degrees horizontally at different turning radii, which makes the illuminated area of ​​the low beam almost doubled when turning, so as to help drivers adapt to the curved road conditions better and faster. When the turning radius is 190m, ordinary headlights can illuminate the curve ahead for about 30m, while dynamic cornering lights can extend the illuminated curve area by about 25m. The dynamic cornering lights also work when the high beam function is activated.

Halogen headlights

Traditional headlights have two sets of filaments, emitting high and low beams respectively. The high beam is brighter and shines farther, and is mainly used for high-speed driving; the low beam is dimmer and shines closer, and is mainly used for meeting other vehicles. When to use the high or low beam is controlled by the driver, and the intensity of each set of beams of the headlights cannot be adjusted, and the angle is also adjusted during the installation process. With the continuous increase in the speed of cars, the lighting of traditional headlights has increasingly shown its disadvantages. When turning, meeting other vehicles, driving in rainy and foggy weather, and driving on highways, the two-beam headlights make it difficult for drivers to see the road clearly, narrow the field of vision, and easily cause dazzle to other drivers.

Traditional headlights are composed of a tightly coiled thin tungsten filament in a bulb filled with inert gas. When current passes through the tungsten filament, it will burn and emit incandescent light. Under the action of high temperature, the tungsten atoms in the tungsten filament are in a vaporized state. Over time, more and more tungsten atoms will evaporate, and the tungsten filament will become thinner and thinner, and eventually burn out. The tungsten atoms will be deposited on the relatively cold glass of the bulb. Over time, a layer of shadow will be formed, blocking the light, and the brightness of the lamp will decrease. Electro-optical engineers have developed halogen lamps to address the above problems. This lamp is a lamp that infiltrates a small amount of iodine (iodine is a halogen element in the chemical elements) into the inert gas in the bulb. The tungsten atoms evaporated from the filament react with iodine atoms to form tungsten iodide compounds. When the tungsten iodide compounds come into contact with the incandescent filament (temperature exceeds 1450℃), they will decompose and reduce to tungsten and iodine. Tungsten returns to the filament again, and iodine re-enters the gas. This cycle continues endlessly, and the filament will hardly burn out, and the bulb will not turn black. Therefore, halogen headlights have a longer life and greater brightness than traditional incandescent headlights. Today's halogen lamp glass is made of quartz, also known as quartz halogen lamps, which can withstand very high temperatures.

Halogen lamps are mainly used as headlights for cars and have a unique light distribution structure. Each lamp tube contains two groups of filaments. One group is the main beam filament, which emits light that is reflected by the lampshade reflector and shoots straight forward. This light source is commonly known as "high beam"; the other group is the partial beam filament, which emits light that is blocked by the sunshade to the upper part of the lampshade reflector. The reflected light is diffused downward to the ground, which will not cause dazzle to drivers of oncoming vehicles. This light source is commonly known as "low beam".

At present, the new type of low wind resistance interior lamps are more popular in the headlight assembly of cars. The appearance matches the outline of the car body and is integrated into the car. At the same time, the lampshade has also been reformed, using a new type of focusing glass, which can provide a farther and wider field of vision and is not easy to cause dazzle to oncoming drivers. Japanese Lexus cars are equipped with such headlights.

Xenon lamp

Although the cost of xenon lamps is higher than that of halogen lamps, they are increasingly valued in automobiles due to their superior performance. Xenon lamps are better than halogen lamps in terms of brightness, color temperature, anti-glare and durability. More and more mid-to-high-end passenger cars are using xenon lamps. Halogen lamps have filaments like ordinary light bulbs, while xenon lamps do not have filaments. This is the most important difference between xenon lamps and traditional lamps. Xenon lamps emit light using the arc generated by the discharger between two electrodes, just like the bright light of the arc generated in electric welding. High-voltage pulse electricity is applied between the metal electrodes in a completely sealed miniature quartz bulb (tube), which stimulates the substances in the bulb (xenon gas, a small amount of mercury vapor, metal halide) to ionize in the arc to produce light. The color temperature of this light is similar to that of sunlight, but it contains more green and blue components, so it appears bluish-white light. This bluish-white light greatly improves the brightness of road signs and signboards.

The luminous flux emitted by xenon lamps is more than twice that of halogen lamps, and the efficiency of converting electrical energy into light energy is more than 70% higher than that of halogen lamps. Therefore, xenon lamps have relatively high energy density and light intensity, while the operating current is only half of that of halogen lamps. The increase in the brightness of the headlights also effectively expands the visual range in front of the car, thus creating safer driving conditions. The transformer and electronic control unit of the xenon lamp control the discharge process of the arc, ensuring the stability and continuity of the light. Since xenon lamps have no filament, they will not be scrapped due to broken filaments, and their service life is much longer than that of halogen lamps. It is reported that the service life of xenon lamps is equivalent to the total operating time of the average use cycle of the car. More importantly, once a xenon lamp fails, it will not go out instantly, but will go out by gradually dimming, so that drivers can gain time when driving at night and pull over in an emergency. Another advantage of xenon lamps is that if they are installed correctly, they will not produce excess glare and will not cause interference to drivers of oncoming vehicles.

The use of xenon lamps increases the freedom of design of the shape of the automobile headlight assembly, that is, it increases the arbitrariness of the design of the front surface of the automobile. By developing a compact headlight assembly, the aerodynamic performance of the automobile is further improved. At present, in order to reduce costs and simplify the structure, some cars use a mixed use of xenon lamps and halogen lamps in the four-lamp headlight system, with xenon lamps used in the high beam system and halogen lamps used in the low beam system, giving full play to their respective performances.

taillight

Although not as dramatic as the development of headlights, taillight systems have also undergone tremendous changes. One aspect of this is intelligence, which is to make the car's taillights perform their work automatically and improve communication with other road users. For example, if the fog lights are frequently forgotten to be turned off or misused, they will automatically be replaced by taillights, but this also depends on specific weather conditions.

Sensors used in lighting systems detect environmental conditions, pollutants, and even speed and traffic information around the lens. When a car is behind you, the input information is analyzed and the taillights automatically change to a "foggy" state, reducing the brightness of the taillights to avoid car accidents. By using pulse width modulation LEDs, the brightness of the taillights can be easily and cost-effectively changed over a wide range. Another smart technology is the automatic emergency rear lights that light up after emergency braking (this technology is already available in some cars, but only after the airbag is deployed).

By using an LED matrix, the shape and brightness of the taillights can be changed accordingly. This approach also provides model-to-model changes during the day and at night, as well as software-driven changes. If an LED matrix is ​​used for the taillights, the shape of the taillights that is currently determined may not be the same in the future. Their shape can be determined and changed by software command, which may depend on legal regulations (brake lights and indicator lights). For example, the brake lights can be changed to a different shape than the reverse lights. Finally, the area illuminated by the brake lights can also be determined by the speed of the car. BMW's concept car X-Coupe has already used this technology. At the beginning of the brake, only the outer edge of the brake lights is illuminated. As the pedal pressure continues to increase, the area of ​​illumination gradually extends inwards. When the brakes are fully applied, the entire area is illuminated.

Currently, red LEDs have begun to be used in a series of automotive brake lights. Their low power consumption, fast lighting and long service life make them more advanced than traditional lights.

Interior lighting

As consumers' requirements for car comfort increase, car manufacturers continue to develop new technologies to ease the psychological pressure between drivers and passengers while driving, and interior lighting technology has become more advanced. Audi A8 has corresponding lighting installed in door pockets, handles (inside and outside), door trims, and the footrest space where drivers put their legs and feet.

However, in fact, the lighting system inside the car is still in a relatively early stage. The lighting method and control are usually achieved by hand, and the lights in other small compartments are only a few discrete ones. The interior lighting system should create a peaceful atmosphere. When the car stops at night and the driver leaves the car, the EL strip can dimly illuminate the door.

This so-called "psychological" approach has been applied to the Mercedes SL series of cars, including: illuminating the footwells for the driver and passengers, creating a comfortable feeling of spaciousness; night lights recessed in the door handles, which help passengers open the doors in the dark; and integrated lights installed in the center of the car's rearview mirror that can emit a gentle light.

To ensure good condition, the SL series cars are equipped with a special sensor to detect the brightness of the surrounding light. The measured information is transmitted to the control module, which ultimately determines the internal light intensity.

my country's car lamp production has broad prospects

The prospect of future automotive lighting systems is exciting. Advanced headlights, variable brightness taillights and more user-friendly interior lighting systems are new automotive lighting technologies that we will see in the near future.

With the increasing rate of automobile use, domestic and foreign automobile manufacturers have rushed to seize the market, forming a trend of competition, thus accelerating the changes in China's automobile market. In the next few years, my country's automobile market will undergo four major changes:

First, foreign automakers are increasingly localizing their sales in China; second, foreign automakers and Chinese automakers are changing in the form of strategic alliances, becoming more flexible and open; third, as Chinese consumers' ability to discern automobiles increases, foreign automakers have to introduce the most advanced models to China for sale; fourth, some major auto producers have begun to produce cars in China and export them to other countries and regions. The changes in the auto market have undoubtedly provided an excellent opportunity for auto parts production, but also raised a series of questions, that is, how to further improve environmental protection technology and product quality, so as to fundamentally adapt to the needs of market changes.

The production of automobile and motorcycle light bulbs, on the one hand, should determine the production plan according to market demand, and on the other hand, should carry out supporting production according to its development and growth rate. With the continuous development of the economy, China's automobile manufacturing industry is stepping towards the world step by step, and the speed of automobile production is also accelerating. It is understood that while automobile production is growing rapidly, it also puts forward higher requirements for the production of auto parts, and it is necessary to produce products that are more suitable for automobile changes. In the production of car lights, such as the production of halogen-type H1, H9 and 800, 900 series new automobile light bulbs, efforts should be made to develop new light sources such as metal halide automobile headlights. However, in some places where the lighting manufacturing industry is more developed and concentrated, there are very few or no signs of the production of automobile and motorcycle lighting bulbs. Many companies lack the necessary technology and equipment when producing such products.

In fact, with the reform of state-owned enterprises and the gradual withdrawal of state-owned economy, private small and medium-sized enterprises can make full use of the excellent technical talents cultivated by state-owned enterprises for many years to develop new technologies for the production of automobile and motorcycle light bulbs, which will also become another way for private enterprises to grow and develop. Industry insiders said that there is a large gap in the production of car lights. my country has existing policy advantages, market advantages, manufacturer advantages, and clustered lighting production groups. If we seize the business opportunities, we will definitely create a group of giants in the production of automobile and motorcycle lighting.