When it comes to car safety and driver assistance systems, ADAS cameras are pivotal.
But how do they work, and why is calibration so important?
In this article, we will discuss the basics of ADAS camera function and explain why calibration is necessary for accurate results and functional safety.
What is an ADAS camera?
An advanced driver assistance system (ADAS) camera is an automotive camera sensor that collects data to assist drivers in performing certain tasks, such as lane-keeping and collision avoidance. Depending on the vehicle and its features, there can be forward-, side-, and rear-mounted ADAS camera sensors
Forward-facing cameras are the most common type of ADAS camera, while side and rear-mounted cameras are growing in popularity. Forward-facing ADAS cameras are mounted to the inside of the vehicle’s windshield, near the rear-view mirror. Most automakers use one forward camera, while some, like Subaru, use two. Front ADAS cameras provide sensor data to inform several ADAS systems, including the following:
- Lane Departure Warning – cameras track road markings
- Lane Keeping Assist – sees lane markings and forward path
- Road Departure Mitigation – sees road edge markings, specifically
- Traffic Sign Recognition (some have a dedicated camera though)
- Forward Collision Warning – cameras look for obstructions
- Automatic Emergency Braking – detecting distance to next vehicle
- Adaptive Cruise Control – detecting and gauging distance to next vehicle
- Pedestrian Detection – determining pedestrians from other moving things
- Automatic high beams – senses light levels, detects vehicles
Rear and side-mounted camera systems are becoming more common. These sensors provide data for several ADAS systems, including the following applications:
- Parking assistance
- Blind spot detection
- Cross traffic alert (rear and forward)
- Around view monitoring
There are many different types of ADAS cameras, but they all work on the same basic principle: using sensors to detect objects in the environment and then processing that information to make decisions about how to respond.
How do ADAS cameras work?
ADAS cameras capture images of the scene. The computer processes these images to identify any objects in the scene. The computer then uses algorithms to track these objects and determine how far away they are from the car. This information is used by the ADAS system to make decisions about how to respond, such as whether to initiate emergency braking or steer away from a potential collision.
ADAS Camera Sensors vs Radar Sensors vs Lidar Sensors
There is some debate about which type of sensor is better for ADAS technology: cameras, radar, or lidar? The answer is that it depends on the specific application. Cameras are good at detecting small, stationary objects, while radar and lidar are better at detecting moving objects. For general purpose ADAS tasks such as lane-keeping and collision avoidance, a camera is usually sufficient. However, more specialized tasks such as autonomous driving, radar, and lidar are necessary for fully autonomous vehicles. Compared to camera-based ADAS systems, radar and lidar are more expensive to implement and maintain. However, they are better at detecting objects in difficult environments such as harsh weather or low light conditions.
|Camera||– High resolution|
– Closest to human vision, detecting colors, and 2D shapes
– Relatively low-cost sensor
|– Sunlight can blind them|
– Poor vision during low visibility weather
– Contrast is an issue
– Depth information not available
|Radar||– Detects in bad weather and in the dark||– Doesn’t have high resolution at range (trouble telling bicycles from motorcycles)|
|Lidar||– High resolution at range|
– Very accurate 3d modeling and object detection
|– Lesser 2D resolution than camera|
– Can’t see through bad weather as well as radar
– High cost
– Requires significant computing power
ADAS Sensor Fusion
In ADAS, redundancy is important, hence sensor fusion. Most ADAS use a combination of optical and radar sensors to detect objects in the environment. By combining information from both types of sensors, the ADAS camera can more accurately identify and track objects in the environment. This means more accurate ADAS warnings and interventions, with fewer false alarms.
ADAS Camera Calibration
Calibration is the process of adjusting the ADAS camera sensor so that it is correctly aligned with the vehicle. This involves setting the camera’s position and angle, as well as its focus and zoom settings.
If the ADAS camera is not properly calibrated, it may not be able to correctly detect and track objects in the environment, which could lead to inaccurate results. In some cases, an uncalibrated ADAS camera may even fail to detect objects that are in plain sight.
ADAS cameras need to be calibrated when removed or replaced, including after windshield replacement. Additionally, changes in alignment and airbag deployment may also be a cause for calibration. Several manufacturers have mandated recalibration of the front windshield camera after all collision repair work, greater than cosmetic repair.
It’s also a good idea to calibrate the camera if you notice that it is not performing as well as it should be. For example, if the camera is having trouble detecting objects, or not working the way it used to, you may need to have it recalibrated.
There are recent studies, identifying camera sensor degradation. Sunlight, car washes, and sand/gravel from roadway driving are some of the contributors to camera sensor degradation.
Calibration is a very technical process that requires special equipment, a controlled environment, and special training. Due to several implementation hurdles, most auto shops cannot even handle calibrating ADAS sensors. As a result, standalone calibration centers are becoming more common. With all the space, equipment, and training needed, ADAS calibration centers can provide accurate calibrations of ADAS sensors quickly and reliably.
Can ADAS calibrations benefit your business?
Car ADAS Solutions offers everything you need to get your own ADAS calibration center up and running. We provide site certification, hardware, software, and training so you can offer this valuable service to your customers. Learn more about our turnkey ADAS solutions.