Apple said in the patent description that the power of the headlights at night is limited by laws or regulations, which in turn will limit the effective range of the sensor, thus reducing the safety of the vehicle and reducing the speed of safe driving of the vehicle.
Apple pointed out that the law limits the power of visible headlights, while infrared headlights can be more powerful. The combination of various complementary image sensing technologies can be used to solve the challenge of object detection and classification in night or low light environment.
For example, the illuminance of a near-infrared illuminator mounted on a vehicle may be loosely limited or unrestricted. A near infrared sensor with a near infrared illuminator can be configured to capture high-resolution image information about objects in or near the vehicle path, and the detection range is significantly longer, up to 200 meters. This can enable the vehicle to detect and classify objects earlier when moving, and improve safety and/or maximum speed. The near infrared illuminator can project near infrared light (for example, a 30-degree cone) in a relatively narrow field of view.
The patent points out that visible light provides the highest resolution, near infrared provides the largest range, and long-wave infrared provides the widest field of vision. Combining these three inputs will make the car have the best model of the situation ahead and around it at night. Apple hopes that this technology can help self-driving cars see the road clearly in the dark, so as to find obstacles and dangers on the road faster.