Essential Guide to ADAS Calibrations: Importance and Process Explained
Advanced driver assistance systems (ADAS) are a collection of technologies designed to enhance vehicle safety by continually monitoring the surroundings to detect potential hazards, reducing the likelihood of human error, which has been proven to minimize the number of road accidents.
Maintaining correct operation involves precisely aligning the system’s components, a process known as ADAS calibration. This ensures the sensors are installed to the original equipment manufacturer (OEM) specifications, especially after certain repairs.
Understanding ADAS Technology
Primary Functions of ADAS
These systems are designed to assist the driver, not necessarily replace it, which is why some of their primary functions consist in alerting drivers to potential dangers of collisions, as the sensors used in these systems are able to recognize cars, cyclists, and pedestrians at up to 50m, giving drivers enough time to react and prevent fatalities.
Advanced Driver Assistance Systems (ADAS) Technologies
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Adaptive Cruise Control (ACC): Fine-tunes your vehicle’s speed in real time, reacting to traffic ahead. Instead of holding a fixed pace, it actively measures the distance to the car in front and slows down or speeds up as needed to keep a safe following gap, making highway driving smoother and more responsive.
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Lane Keeping Assist (LKA): Centres the car to the middle of the lane when it detects an unintentional drift from its travel lane.
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Blind Spot Monitoring (BSM): Also known as blind spot detection, warns the driver when the system detects other cars located in the driver’s blind spot, such as the side and rear.
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Automatic Emergency Braking (AEB): Applies the vehicle's brakes when it detects vehicles and pedestrians in front.
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Lane Departure Warning (LDW): Monitors lane markings and vibrates the steering wheel to warn the driver before they unintentionally drift out of lane.
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Parking Assist (PA): Automates steering and braking systems to guide vehicle parking.
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Traffic Sign Recognition (TSR): Keeps the driver informed about the current speed limit.
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Night Vision (NV): Uses thermal imaging systems or infrared cameras to detect temperature differences and notify drivers of pedestrians or animals in front of the car and other potential risks.
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Driver Monitoring Systems (DMS): Continuously scans the driver’s face and eyes to monitor their behavior, which may indicate fatigue or lack of attention.
ADAS Components, Sensors, and Cameras
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ADAS systems rely on various components to monitor vehicle surroundings and enhance driver safety, however, the most important sensors include:
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Camera and video sensors:
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Front-facing camera sensors, which are typically mounted inside the windshield, detect vehicles, pedestrians, and road markings.
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Stereo video cameras are used in different systems such as emergency braking, lane-departure warning, and road-sign recognition.
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Radar sensors: Measure distances from obstacles and their relative speeds, which is why they are typically used in collision warning systems.
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Forward radar sensors are located in the front bumper and assist in maintaining following distance, crucial for ACC.
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Rear radar sensors are in a vehicle's rear corners and help monitor objects approaching from the rear and sides, helping with blind spots and rear cross-traffic warnings.
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LiDAR sensors: Light Detection and Ranging sensors provide accurate distance sensing, crucial for LKA, emergency braking, and more.
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Ultrasonic sensors: Primarily used for short-range detection, are used to aid navigation in tight spaces and assist in reversing by giving the driver an indication as to how much space there is behind the car.
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Steering angle sensors: Measure the steering angle, allowing interpretation of driver actions required for functions such as LKA.
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Yaw Rate Sensors: Detect rotational movement around the vehicle’s vertical axis, helping maintain stability.
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Wheel Speed Sensors: monitor individual wheel speeds, allowing ABS to prevent wheel lock-up during braking.
The collected information from the aforementioned sensors, as well as other sensors, along with vehicle CAN data, is then processed by powerful software and computers to ensure that the automated vehicle can move safely through traffic. In this way, driver assistance systems rely on accurate sensor readings, which is why most ADAS sensors need to be precisely aimed and require calibration if their positions are disturbed.
What is ADAS calibration?
ADAS Calibration Process
The calibration process depends on the type of driver assistance system and the sensors involved, as modern vehicles may require either static or dynamic calibration, or even both, depending on the manufacturer’s recommendations.
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Static calibration is performed in a controlled environment while the vehicle is stationary using a fixed calibration target placed in front at specific distances. Static Calibration requires specific conditions such as a broad, clear space (~9x15m), a level floor (<10mm uneven surface), uniform and neutral color walls and floor, specific lighting conditions, like no direct sunlight, and the absence of reflective surfaces, as they could cause interference.
- Dynamic calibration requires driving the vehicle at certain speeds so the system can adjust in real-time using live road data. For this process, it is necessary to have the car connected to a diagnostic tool, and it is recommended to drive on clearly marked roads and sometimes in the presence of other vehicles while maintaining a safe distance to calibrate the system effectively.
Both static and dynamic calibrations ensure vehicles' ADAS systems operate accurately and safely.
Steps Involved in the Calibration Process
The ADAS calibration process typically involves the following steps:
1. Review of Manufacturer Specifications: Before beginning, technicians must consult the vehicle manufacturer's guidelines to understand the types of ADAS sensors and cameras used, their placement, and specific calibration requirements.
2. Pre-Calibration Inspection and Preparation: Technicians examine the vehicle to identify any damage, obstructions, or modifications that might affect sensor alignment.
3. Setup: The vehicle is positioned on a level surface, and calibration targets or specialized tools are set up according to OEM specifications.
4. Calibration: A specialized diagnostic tool or tablet is connected to the OBD-II port to enable communication with the ADAS sensors and initiate the calibration procedures, whether static or dynamic.
- Static: Sensors are calibrated while the vehicle remains stationary, ensuring they correctly detect objects within the intended range. Typical static calibration procedures may include manual adjustments depending on the vehicle's specifications.
- Dynamic: The vehicle is driven under specific conditions, allowing systems to adjust and fine-tune their functionality. This process may require one technician driving the vehicle while another operates the calibration tool.
5. Verification & Testing: Final tests are performed to confirm proper calibration and system accuracy.
The Importance of Professional ADAS Calibration Process
Since automated driving systems influence critical vehicle functions such as powertrain, brakes, and steering, precise ADAS calibration is vital. Incorrect calibration can cause malfunctions and increase the risk of accidents. For this reason, these services must be performed by trained technicians who must adhere to strict standards to guarantee that ADAS sensors and cameras are properly calibrated.
Technicians with certifications such as I-Car or training from courses like Hella Gutmann have the expertise to identify each vehicle's ADAS components, locate sensors correctly, and troubleshoot calibration issues when needed. These skills, paired with specialized, high-precision equipment, ensure that ADAS systems function reliably.
ADAS Calibration Equipment and Software
To perform calibration, specialized equipment and trained technicians are required. The process often involves the use of a diagnostic tool or tablet compatible with calibration software, measuring devices such as tape measures or lasers, and specific accessories such as metal reflectors, cones, pyramids, and calibration targets, which as are panels with specific patterns, that vary by sensor type, vehicle manufacturer, model, and year.
Calibration targets must meet strict standards, whether from original manufacturers or reputable aftermarket brands that can guarantee high precision. DIY or non-compliant targets are unacceptable, as they can lead to inaccurate calibrations, compromising the functionality and safety of ADAS systems.
Besides the ADAS calibration equipment, workshops also need instruments like an alignment rack to precisely align the wheels and suspension, as proper wheel alignment is crucial for ADAS systems because a misaligned wheel can affect sensor readings and the performance of the safety system.
In addition to the hardware, it is also important to have access to software tools as they streamline the calibration process and help technicians maintain strict OEM standards. For instance, solutions such as:
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Autel IA900 & IA700: Provide a complete solution, integrating diagnostics and ADAS calibration into a single system. Autel can perform an all-systems scan, detecting faults in ADAS components, allowing for precise troubleshooting.
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Tru-Point calibration systems: work with any ADAS-capable diagnostic tool, ensuring flexibility across different vehicle models.
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Hella Gutmann mega macs software: Assists in the calibration of reversing & surround view cameras.
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Hella Gutmann CSC-Tool: Features extensive extensions that support calibration for cameras, radar, and complex components like the Audi laser scanner.
References
- Automated Driving and Driver Assistance Systems - Tom Denton (2020)
- Advanced Driver Assistance Systems (ADAS) - HELLA
- How to Choose the Right ADAS Calibration Targets for Your Business
- Everything You Need To Know About ADAS Calibration
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