The car at the wheel

That has been the standard since the invention of the automobile. But now the industry is moving toward a new vision as more of the tasks traditionally carried out by the human are taken over by the machine, with the goal of making traffic situations safer for all of the various participants. Adaptive cruise control slows the car down when it comes too close to the vehicle in front of it; the blind spot assistant warns of vehicles approaching from the side; the lane assistant notifies the driver if the car unintentionally drifts to the edge of the lane.“It started with technologies that assist the driver and help them to better anticipate and overcome dangers, such as emergency braking assistance, improved rearview mirrors, and intelligent headlights,” says Dr. Steffen Runkel, Head of Optics at Bühler Leybold Optics. “But increasingly, it means the car itself is making the decisions.”
 

The technology that enables cars not only to sense their environment but also to take sensible decisions comes from the field of optics.

Optical sensors are at the heart of this. Sensors can scan the environment and detect the size and distance of objects. Projection modules are then needed to communicate relevant information to other road users in the vicinity – a prerequisite for autonomous driving. Both sensors and projection modules can be integrated into various parts of vehicles. The smartest location for them, however, is most likely within advanced lighting units, as these have to be integrated into the car body in any case.

To scan and detect the environment accurately, the sensors need to be able to sort out the important information from distractions, like reflections from sunlight, for example. In other words, they need the kind of filter that the human brain applies to the information we receive from our senses.

Leybold Optics in Alzenau, Germany, specializes in this area. Over 20 years ago, its HELIOS sputter coater technology was developed and is used to manufacture exactly this type of filter. Known as a band-pass filter, it consists of a specific sequence of nanometer-thin optical layers created using the sputtering method. “A material like silicon or tantalum is used for the coating. We call this the target. It is placed as a block in the sputter cathode,” explains Dr. Runkel. “With the help of an energetic plasma, individual ions are created which bombard the target material. This ejects individual silicon or tantalum atoms out of the target material, which in turn condenses on the filter. By adding oxygen gas, these layers oxidize and become transparent. This results in several nanometer-thin layers of various materials. Depending on the composition, they filter different wavelengths and can thereby block unwanted reflections from sunlight or the distracting light from other vehicles when driving at night. The sensor detects only the light that is wanted, sent out from a laser, and reflected back by the surroundings of the car.”

According to a report published by the consulting firm McKinsey in January 2023, even if the road to autonomous driving is proving longer than the first visionaries expected, there is a consensus gathering around its potential to transform transportation and society as a whole. Today, most cars include basic advanced driver-assistance systems.

By 2030, the consultants forecast that the value of the hardware market to support autonomous driving, including domain control units, cameras, sensors, LiDAR, and radar, could be between USD 55 billion and USD 80 billion. The combination of all three of these technologies is seen as the way forward because each of these sensors works at a different distance.

“Many of these ideas are still in development,” says Dr. Runkel. “It is already clear that the car of the future will learn to see through a variety of smart sensors based on optical and radar technologies. Our solutions can support the industry in driving toward this goal and making mobility safer for everyone.”