During his 2022 LPMS presentation, Pierrick Boulay, a senior analyst for Yole Développement, gave an overview of advanced driver assistance system (ADAS) applications and highlighted the increasing role of light detection and ranging (lidar) sensors within vehicles (see figure).
A key takeaway, he says, is that a combination of multiple ADAS applications will be necessary to reach high levels of autonomy—and it’s fueling an ever-increasing need for sensing and computing power.
One example of an ADAS application is how the lane-departure warning has evolved into the lane-keeping assist, which may steer you back into your lane if you start to drift out of it. “This is Level One driving automation,” he explains. “Another Level One application is adaptive cruise control, which has evolved to analyze who is comfortable with stop-and-go functionality, and the two have now merged into a new application called traffic jam assist. It corresponds to Level Two of autonomous driving, with lateral and longitudinal driving.”
Automotive lidar sector
A widely diverse group of companies make up the automotive lidar sector—at different levels of maturity. “Mechanical lidar at 905 nm still dominates the market,” points out Boulay. “And the use case has a direct impact on the position of the lidar and its specifications, but no one lidar fits all applications.”
The location of lidar within vehicles is evolving, too—it was first found in the grill, but has shifted to other locations such as the roof, windshield, bumpers, or fenders.
Higher-end vehicles (average ASP price $100,000), known as the F segment, are where innovations using state-of-the-art sensors and computing are happening. In 2020, an average of $3000 worth of ADAS content was used in these vehicles.
Lower-end vehicles (average ASP price $30,000), known as the C market, makes up the bulk of sales and included about $300 worth of ADAS content in 2020.
Boulay expects to see more ADAS content make its way into lower-end vehicles as its price continues to drop.
Teardown of MEMS lidar
In a RoboSense teardown of a RS-LiDAR-MI, one of the first automotive microelectromechanical systems (MEMS) lidars, they found “silicon photomultipliers (SiPMs) as receivers, which shows higher complexity compared to mechanical lidars,” Boulay says. “Opening it reveals a MEMS scanner and five optical modules containing one laser diode and one SiPM each. It operates 905 nm lasers with direct time-of-flight (dToF) for range evaluation, and its maximum range is 150 m with a 10% reflectivity target.”
Most lidar manufacturers use edge-emitting lasers (EELs) at 905 nm due to their relatively low cost and ready availability. “And most players use vertical-cavity surface-emitting lasers (VCSELs) for short-range flash lidar, although they can be used for long-range as Ouster is doing,” Boulay says. “A limited number of lidar manufacturers are using fiber lasers.”
Lidar photodetector usage
An avalanche photodiode (APD) is the reference photodetector for lidar. “It’s available in automotive grade and was one of the first photodetectors used in lidar, so the majority of lidar companies are using it,” Boulay notes. “Single-photon avalanche diodes (SPADs) are gaining traction and are being used in consumer applications—high volumes of high-quality photodetectors are available. Silicon photomultipliers (SiPMs) still aren’t used by many lidar players, but this may change in the future with improved performance.”
In frequency-modulated continuous-waves (FMCWs), he adds, coherent detection is used and a photodiode is sufficient for detection.
Sensor integration
As far as integration of sensors today, a car can monitor objects ahead and behind but can’t detect anything at its sides, although surround cameras are placed on the sides of vehicles to enable viewing applications.
As lighting becomes more horizontal, it creates “opportunities to integrate more functionalities for communication and to integrate sensors,” says Boulay. “Lidar will likely be implemented behind the windshield, making it the first combination of a forward ADAS camera and 3D lidar.”
Market consolidation, growth ahead
Consolidation is ahead for the lidar industry, Boulay cautions. “There are too many LiDAR companies compared to the number of OEMs willing to implement lidar,” he points out. “Oryx went bankrupt in 2019, and Aurora acquired Blackmore the same year. Other lidar companies will follow this path.”
Boulay expects the lidar automotive market to grow fast, especially after 2023, and reach $2.3 billion in 2026.
