The Highlights of Headlight Technology
Since the development of LED lights for use in the automotive sector, we have seen a raft of innovations in both interior and exterior lighting. The design constraints of traditional headlights have been thrown off, and OEM’s are quickly embracing the new possibilities that LED’s provide.
Not only have LED’s enabled manufacturers to create new designs in terms of aesthetics, but the use of a number of different LED’s in headlight modules also allows much greater functionality in terms of improved visibility, glare-free technology, and digitally controlled systems. This month we’re taking a look at some of the innovative headlight technologies that have hit the market this year, and those that can be expected to feature in new cars during next year.
Lighting specialists, HELLA, have developed a range of innovations over the last decade for the automotive industry, and in 2014 won Automotive News PACE Award for its adaptive LED Matrix Beam technology.
Earlier HELLA technologies included the Adaptive Frontlight System (AFS), which uses the steering angle and vehicle speed as parameters to determine the illumination of the road. Based on that information, the lighting module is used to create different types of light distribution, such as town, country, adverse weather, and motorway lighting. The system was further developed with the Adaptive Cut-Off Line (aCOL), which uses data gathered about the vehicle’s surroundings to determine the correct light distribution. An on-board camera is used to detect oncoming traffic and vehicles in the road ahead, and the system adjusts the position of the lighting module accordingly so that the light cone ends directly in-front of oncoming traffic, or directly behind the vehicle ahead.
The glare-free high beam function allows the lights to be on full beam constantly, and if the camera detects an oncoming vehicle, the distribution of light is adjusted to mask the specific area and avoid dazzling other road users. Further to this, the functionality of the Matrix Beam technology will also incorporate a targeted spotlight function, whereby certain objects – such as a pedestrian to the side of the road – can be illuminated to alert the driver’s attention to their presence and enable quicker response times to avert potential danger.
HELLA’s Matrix Beam technology was an industry-first, which uses 25 individually-controlled LED’s in a matrix formation to enable a wide variety of lighting patterns. The high beam is split into five reflectors, each one having a chip containing five LED’s.
The system utilizes a front-facing camera, high-performance software, and ‘intelligent lighting’ to recognize cars that are being followed, as well as oncoming traffic. Each of the LED’s can be individually dimmed or turned off depending on traffic conditions to avoid dazzling other drivers. The LED’s can also be combined to create up to eight ‘dark zones’ with light in-between, allowing the driver to benefit from full beam at all times, without affecting other road users. In addition, the system is also able to react to driving conditions, such as negotiating a bend, whereby the dynamic bending light function is utilized to increase the intensity of the light cone on one particular side of the vehicle as necessary to improve visibility as the car turns the corner.
Another interesting development in the lighting sector was unveiled by OSRAM Opto Semiconductors at the Vision Congress in Paris, in October 2014. The company has developed and LED which can achieve an output of 1400 lm and 200 Mcd/m² in the laboratory – a luminance three times that of existing versions.
The brightness has been achieved through a combination of UX:3 chip technology, ceramic conversion technology, and high-current technology used in projection applications. The result is that a single LED can be used to provide the complete low beam, where in the past this was only possible with the use of several LED chips. The unit measures just 30mm x 50mm, and offers the potential, when commercially available, for designers to create much smaller headlights with equal functionality.
Although no specific timeline has been set at this stage, OSRAM expects this technology to be available to OEM’s within the next few years.
OEM’s have been quick to implement these new technologies, and earlier this year Mercedes revealed that it is to use Multibeam LED Headlights on the 2015 CLS-Class. The system is based on HELLA’s Matrix Beam technology, and will feature the advantages detailed above, via the use of camera on the windscreen and four control units per car which calculate the ideal light pattern depending on traffic and road conditions. Each LED can be individually-controlled and dimmed in 255 stages to create the perfect lighting for any given situation.
The system also features a unique lighting function for roundabouts which is navigation-based. When the vehicle approaches a roundabout the cornering light function is activated to both left and right, to ensure maximum visibility at an early stage before entering the roundabout.
Mercedes has already indicated its intention to take this technology further by developing a Multibeam module with 84 individual LED’s; with more LED’s eventually leading to a point where light can be controlled entirely digitally, without the need for actuators to physically change the position of the lighting module. The company has also unveiled plans to release a ‘high range’ LED high beam headlight, which will be able to illuminate the road up to 600 metres ahead.
Audi has also developed matrix LED technology, which will debut on the 2015 A8, and earlier this year became the first automaker (just ahead of BMW) to release a car with laser headlights, when they were added to a limited edition LMX version of the A8 in May this year. The lasers emit a blue light which is passed through a phosphor to convert it to white light with a colour temperature of 5500 Kelvin. Audi state that the pioneering headlights can offer twice the illumination range of all-LED headlights, and it will be interesting to see which route the manufacturer takes with headlights for its vehicles in the next few years.