Apple was granted a patent for the night vision system that combines visible light, near-infrared (NIR), and long-wave infrared (LWIR) sensors. Apple’s patent explains that self-driving cars have the same limitations as human drivers when it comes to seeing at night, citing the typical 60-meter (200 feet) range of car headlights.
Nighttime or low-light environments present challenges for automated vehicle control systems. For example, the illumination level provided by headlights on a vehicle at night may be limited by laws or regulations, which may in turn limit the effective range of a visible spectrum sensor (e.g., a camera) used for detecting objects in or near the path of the vehicle. Having a limited effective range of around 60m for detecting and or classifying objects can reduce safety and/or reduce the speed at which the vehicle can travel safely.
A combination of multiple complimentary image sensing technologies may be employed to address the challenges of nighttime or low-light environment object detection and classification. For example, there may be looser or no restrictions on the illumination level of a near infrared illuminator mounted on a vehicle. A near infrared sensor with a near infrared illuminator can be configured to capture high resolution image information about objects in or near a path of the vehicle out to a significantly longer range of around 200m from the vehicle. This may enable earlier detection and classification of objects as the vehicle moves and improve safety and/or maximum speed. Near infrared illuminators may project near infrared light in a relatively narrow field of view of around 30°.
The patent notes that visible light provides the highest resolution; NIR provides the greatest range; and long-wave IR provides the widest field of view. Combining input from all three would give the car the best possible model of what is in front of and around it at night.
