Improve Lidar Detection with Near Infrared Reflective Dark Automotive Paint Colors

As the technology that enables a self-driving car to see its surroundings, Lidar plays a key role in the race to bring fully autonomous vehicles to our roads.

Self-driving cars rely on a continuous stream of data and information from Lidar readings and other detection technologies to safely navigate the roads. Despite the rapid growth and accelerated development of this new mobility technology, it is still a challenge for Lidar to detect dark-colored vehicles on the road.

Lidar utilizes radiation at wavelengths within the near infrared (NIR) region of the electromagnetic spectrum. These wavelengths are absorbed by many of the dark colors currently offered by the OEMs. This inability to detect another object results in a compromised mapping of the autonomous vehicle’s environment. 

BASF is leveraging Lidar-detectable coatings made with functional pigments and technologies to help reduce NIR absorption and thereby improve Lidar mapping performance. 

Automotive colors require Lidar functional pigments

Dark colors such as black, grey and blue currently pose a challenge for self-driving vehicles. Carbon black-based pigmentations are typically used in dark automotive paint colors and these absorb NIR radiation.

When a carbon black pigment is used in a dark color, or even in small quantities to tint a light color, the coating will absorb the NIR radiation, resulting in lower Lidar reflectance.

With the use of BASF’s functional pigments, OEMs are able to replace the NIR absorptive pigments used in the color formulation with Lidar-transparent or reflective pigments that will facilitate the reduction of NIR absorption. 

BASF delivers solutions that combine functionality and aesthetics to address the challenges brought on by the evolving nature of mobility. These functional pigments allow OEM design teams to expand their color portfolios for future vehicles, while still achieving the necessary level of Lidar radiation detection.

In fact, as part of its 2018-19 Automotive Color Trends portfolio, BASF designed a dark color with Lidar detectability in mind.

Centripetal Blue is a blue-black color with a medium coarse sparkle that incorporates functional pigmentation into the car paint. We presented this color to OEM design teams to address the NIR reflectivity challenges as vehicles with higher levels of driving autonomy hit the roads,” said Paul Czornij, head of design North America at BASF’s Coatings division. 

Lidar-detectable coatings help increase visibility  

How the coating system is assembled also impacts how well NIR radiation is reflected back to an autonomous vehicle. Specifically, there needs to be a Lidar-reflective layer within the coating system, otherwise the Lidar radiation will be absorbed by subsequent layers within the coating stack.

With BASF’s Lidar-detectable coatings, the NIR radiation comes into contact with the dark colored basecoat layer and instead of being absorbed, freely travels through without significant absorption. A subsequent Lidar-reflective coating layer then serves as a ‘mirror’, reflecting the NIR radiation back to its point of origin for calculation of distance and mapping of the environment.

Lidar-transparent pigments and Lidar-reflective layers can be brought together within the coating system for optimum performance.

Enabling diversity for automotive paint colors

More than ever before, the paper-thin layer of an automotive coating provides a functional purpose. BASF’s pigments and coatings expertise helps OEMs to achieve a beautiful aesthetic that aligns with future customer preferences, while addressing the safety and performance needs driven by the development of increased vehicle autonomy.

Through extensive research, BASF design experts predict future car paint colors will be diverse, ranging from achromatic colors, through pastels to bright, chromatic hues. In addition, dark colors like blue and gray are expected to grow in prominence, and Lidar-detectable pigments and coatings will help OEMs deliver on a broad color portfolio as we enter this new era of autonomous driving technology.

To learn more, please contact BASFAutomotiveSolutions@basf.com.