Due to vehicle safety and awareness advancements, infrared sensors are becoming more popular in vehicles for advanced driver assistance systems (ADAS), in-cabin sensing, and driver monitoring systems (DMS).
IDTechEx’s latest report, “Infrared (IR) Cameras for Automotive 2025-2035: Technologies, Opportunities, Forecasts”, explores the types of infrared sensors that are commonly used and forecasts for the future of their uptake.
ADAS and Infrared Sensors
Near-infrared (NIR) sensors are used primarily for driver and occupant monitoring systems and are expected by IDTechEx to become standard for all autonomous vehicles. On the other hand, short-wave infrared (SWIR) will play a large part in vehicle autonomy, and it is used for ADAS features to enhance safety outside and inside the car.
Long-wave infrared (LWIR) can similarly be used in ADAS for automatic emergency braking and sensor fusion with camera and radar. The increasing adoption of ADAS on regular vehicles alongside safety regulations will also create more opportunities for IR technologies.
Radar and LiDAR already have a well-known presence within most autonomous driving systems, commonly combined with visible light cameras.
However, infrared cameras can increase the functionality of these existing systems, making them less affected by adverse weather conditions and low visibility, such as at nighttime and in mist and fog. IR sensors cannot detect colour, meaning that infrared sensors cannot reliably read traffic lights and signposts.
IR sensors detect light of wavelengths that humans can’t see, which either exist in the imaging environment or are introduced via an illuminator. Sensors can then pick up these wavelengths and convert them into greyscale images.
SWIR, NIR, and LWIR
SWIR are known for their night vision and low-light visibility conditions, such as fog or mist, as they can maintain functionality. SWIR sensors are also sensitive to different materials, even if they are of the same colour, allowing the detection of black ice or wet road conditions. These properties allow for enhanced object detection to avoid collisions.
NIR systems need illumination, so they will emit a light source, such as an LED, which can then be reflected to the sensor with data from the environment. In-cabin sensing is the main application for NIR technology, as it detects the driver’s attentiveness levels by monitoring drowsiness, phone use, and seatbelt use. NIR cameras can acquire images similar to visible light and work in dark conditions, making them perfect for ADAS for night driving.
LWIR sensors, on the other hand, work passively by detecting body heat, meaning it is easier for them to identify pedestrians and animals, more so than other technologies. This technology is most commonly seen in higher-end vehicles as an ADAS add-on, however with increasing vehicle safety regulation, IDTechEx expects LWIR to see increased adoption for features like automatic emergency braking.
Drawbacks and Outlooks for Infrared Sensors
IDTechEx describes that the longer an IR sensor’s wavelength, the worse the image resolution, meaning there can be limited dynamic range with IR technology. There is also the question of alternatives to IR sensors already being established, such as LiDAR and radar, which also have suitable performance capabilities in adverse weather conditions and can provide distance and velocity information.
Therefore, SWIR startups must be introduced at a feasible price to compete with existing technologies. IDTechEx reports recent cost reductions in SWIR technology, making it more viable for OEMs to implement them.
The possibility for IR sensors to be combined with standard image processing makes it an attractive feature to include alongside existing technologies, and with their unique benefits and adaptability, infrared sensors will continue to infiltrate the automotive industry.