It is impossible to predict what the ‘car of the future’ will look like exactly. But, certain patterns are evident in the technology being seen in prototypes and concept cars – and it is clear that light-based technology will play an important role to ensure driving safety and comfort.
To shed light on the latest developments in optoelectronics for automotive related applications, Automotive Industries (AI) spoke to Christoph Neureuther, Senior Manager Marketing Automotive Interior and Joachim Reill, Senior Director Automotive Application Engineering at Osram Opto Semiconductors.
AI: Adaptive headlight lighting solutions have made a major impact in recent years. What are the new technological developments?
Reill: Adaptive LED headlamps have so far worked with individually controlled chips for each lighting area. We now see a trend towards LED chips with micro-structured pixels that can be lit or turned off individually and even automatically to avoid dazzling traffic participants.
As part of the research project "μAFS" (micro AFS), a group of German companies under the coordination of Osram Opto Semiconductors, successfully worked on the foundations of a new class of energy-efficient LED headlamps for adaptive front lighting systems. We have developed the world's first hybrid LED. With the "Eviyos" (Efficient, Versatile, Intelligent, μ-structured LED Chip by Osram Opto Semiconductors), our developers made a big step towards the market maturity of a high-resolution and intelligently controllable multi-pixel LED.
Eviyos combines a light emitting diode array chip and an individual silicon pixel control IC. 1,024 LED pixels in Eviyos, each just 0.125mm x 0.125mm in size, receive their brightness and current setting from an electronic control unit which merges sensor information and camera input. The camera acts as the “eyes” of the system, capturing the information about the surrounding environment and forwarding it to the controller. The controller processes the image data information and forwards an adapted light distribution pattern to the pixels. In addition to exceptional adaptive capabilities, the active electronic control ensures high energy efficiency by turning on only those pixels which are needed. Eviyos is expected to be launched in early 2019 as a new product family with versatile application options.
AI: What are the latest trends in LiDAR applications?
Reill: LiDAR (Light Detection and Ranging) is now commonly viewed as THE technology paving the way to (semi-)autonomous driving. LiDAR works on the principle of radar, but uses light pulses emitted by an infrared laser diode. Our pulse laser diodes have been in use in cars for 10 to 15 years in applications such as the measurement of distance in adaptive cruise control systems. We have also been involved in the development of laser sensors for advanced driver assistance systems and for autonomous and semi-autonomous cars for many years. Scanning LiDAR will play a major role here, but the units need to become smaller, less expensive and more robust. Lasers are a key factor in this equation, not only in terms of achievable optical power, but also as an enabler of innovative sensor designs.
The latest developments have seen various multi-beam LiDAR systems, which generate an accurate, three-dimensional image of the vehicles’ surroundings. We are expanding our portfolio to single and multichannel SMT lasers to provide support for the many new developments in sensors for self-driving cars.
AI: What about LiDAR technology?
Reill: We have improved the pulse laser diodes with a wavelength of 905 nanometers. The nano-stack laser diodes now deliver a maximum optical output of 85W at 30 amperes, which is approximately 10W more than before. The pulse length of less than 5 nanoseconds (ns) is remarkable compared with the previous 20ns. The short pulse length and the small duty cycle of 0.01 % ensure that even at high outputs the requirements of the relevant eye safety standards are met. With an operating voltage of 24V the laser also meets the requirements for use in vehicles.
In addition, many providers are now developing solutions based on MEMS (Micro-Electro-Mechanical Systems) technology that replaces mechanical deflection with mirrors to direct the laser beam. Aside from being more compact and less susceptible to wear and tear, they bring down system costs. We expect Scanning LiDAR will soon be found in most mid-range cars.
AI: How will the current trends influence interior design?
Neureuther: As cars become more autonomous the interior will become an extension of our living space. Light will become an integral part of the passenger cell, taking on both functional and design-specific tasks. Light sources in car interiors will provide ambient lighting and perform a number of additional functions. For example, they could use dynamic and color effects to draw the driver’s attention back to the traffic.
AI: What technological developments drive this evolution?
Neureuther: Miniaturization and multi-chip-technology have made it possible to include more functions in a limited space. The latest developments add intelligence to the LED by integration of an IC for easy driving and control of RGB LED.
As a member of the Iseled Alliance (Integrated Serial/Smart Embedded Light Emitting Diode) we are driving this development. At electronica 2018 we presented the prototype of the multichip Osire E4633i LED which will provide uniform color appearance as well as fast adaptation to dynamic light scenarios. Control of color and brightness has been simplified because the pre-calibrated Osire E4633i can automatically correct the color shifts in the red range caused by temperature fluctuations. The LED has an extremely compact pre-mold SMT package with a footprint of 4.6 mm x 3.3 mm x 0.7 mm. The compact package and the link to the serial bus allow implementations with more LEDs in a much smaller space. This first prototype is the start of a whole product family addressing ambient applications with demand on true RGB color capabilities.
AI: What other technologies do you see being applied to automotive applications?
Reill: We should definitely look at the utilization of projection technology and hybrid solutions combining this technology with multi-pixel solutions. In September 2018 we introduced the new Oslon Boost HX, which provides classic illumination of more than one million pixels, as well as the ability to project information onto the road. Future headlights may, for example, project two guide lines the width of a car apart, enabling the driver to negotiate roadworks more safely. Projections may also be used to tell drivers that they are too close to the vehicle in front, or warn them that they are approaching roadworks, icy patches or other hazards.
Oslon Boost HX delivers exceptional luminance of more than 200 cd/mm², taking light-based driver assistance systems and communication with the driver into new territory. Special chip technology with high ampacity can be operated at 3 A/mm² to ensure high luminous flux – and most importantly for this target application – high luminance. Its 2 mm² chip emits at least 1,400 lm at a current of 6A. The package has been optimized to make use of the high current capability of the chips and to conduct heat away from the component. The robust 4mm x 4mm ceramic package is easy to handle. Passive DMD solutions herald the start of a broad range of applications. More efficient active solutions for glare-free high beam and projection as well as other Oslon Boost derivatives will follow.
AI: Are there other examples of technology transfer trends?
Reill: Applications in mobile and consumer technology have triggered a spurt in the development of biometrics technology. The automotive industry could be the next to see a surge in uptake, as the concept car “Snap” by Rinspeed has demonstrated. Biometrics technology – from fingerprint scanning to facial recognition or iris-scan – is largely considered to offer a high degree of security and is extremely user-friendly. Automotive manufacturers are considering the use of these systems for car access, driver recognition or access to in-car data systems.