Most advanced driver assistance systems (ADAS) now have impressive features, including:
- Automatic emergency braking
- Parking assistance
- Blind-spot monitoring
- Forward collision warnings
- Adaptive cruise control
- Traffic sign recognition
- Lane detection and lane departure warnings
These systems are capable of offering so many advanced safety features largely because they rely on multiple types of ADAS sensors, each of which has its own unique strengths and vulnerabilities and complements each other.
In this post, we’ll discuss the four key types of ADAS sensors technicians and repair shops need to be familiar with, including the pros and cons of each, which features they support, and essential ADAS calibration needs.
Camera sensors
ADAS camera sensors use video and image sensors to detect objects and provide drivers with real-time images. These sensors are often used for ADAS features like parking assistance, collision avoidance, and lane departure warnings.
When it comes to different types of sensors in cars, camera sensors currently produce the most high resolution images and are highly effective at detecting 2D shapes and colors accurately. It’s important to note, however, that camera sensors may have reduced performance in poor weather or lighting conditions.
LiDAR sensors
LiDAR sensors send out laser pulses, which bounce off surrounding objects, and then measure how long it takes for those pulses to return. This allows the sensors to calculate precise distances between a driver’s vehicle and other objects.
LiDAR sensor technology is currently some of the most advanced out of ADAS sensors. It offers strong potential in supporting autonomous driving features, and currently supports ADAS features like object detection and avoidance, adaptive cruise control, blind spot detection, and lane detection.
These sensors are capable of creating high-resolution detection even at a far range and has outstanding 3D mapping capabilities.
Sonar sensors
Sonar sensors use sound waves for object detection, emitting sound waves and determining how long it takes for the sound to return. They’re most effective at detecting objects at close range, and are helpful for object detection even in tight spots; they aren’t as effective for object detection at a far range.
As a result, these sensors are typically used for features like backup detection and parking assistance.
Radar sensors
Radar sensors use radio waves to detect an object’s distance and location. They can be used to help assess another vehicle’s speed, supporting features like adaptive cruise control, forward collision warnings, lane departure warnings, and automatic braking.
These sensors function well regardless of weather or light conditions, though they may have more difficulty detecting objects effectively at a far range.
Radar vs sonar vs LiDAR sensors
Radar, sonar, and LiDAR sensors all work similarly: They emit radio, sound, or light waves respectively and assess how long it takes for the sound to return back. They’re all used for object detection, but they each have their own pros and cons that complement each other.
Radar sensors and sonar sensors, for example, function well regardless of weather or light conditions. LiDAR sensors perform well in all light conditions, but performance can be impacted by inclement weather like falling rain or snow.
LiDAR sensors, however, can deliver the highest resolution at range, resulting in accurate object detection, modeling, and 3D mapping, even at far range. Radar sensors and sonar sensors both may have difficulty accurately identifying some objects at far ranges, and sonar in particular is most useful for close object detection.
Sonar’s biggest advantages are its ability to strongly and accurately detect objects closeby, including in tight spaces, and its low cost to produce and install. LiDAR in particular is much more expensive, though future developments may aim to reduce overall costs.
Radar sensors function, pros, and cons
Functions: Use radio waves to detect distance and object location
Pros: Strong performance despite weather or light conditions
Cons: Difficulty accurately identifying some objects at far range
LiDAR sensors functions, pros, and cons
Functions: Uses light from a laser to calculate object distance
Pros: High resolution at range resulting in accurate object detection and modeling. Excellent 3D mapping
Cons: Potentially impacted performance in inclement weather, like active rain or snowfall
Sonar sensors function, pros, and cons
Function: Uses sound waves for object detection
Pros: Low cost. Strong ability to detect close objects even in tight spaces
Cons: Short detection ranges. Potential difficulty accurately detecting small or soft objects
