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ADAS Under The Hood: Driver Attention Warning Systems and their Calibration Requirements

December 20, 2024

LD Warning

When a driver falls asleep at the wheel, their average reaction time is exactly zero seconds. 

According to AAA Foundation research, 16.5% of fatal crashes involve a drowsy driver

Driver Attention Warning (DAW) systems have since emerged as a critical line of defense against drowsy and distracted driving. 

As these systems become standard equipment on new vehicles, understanding how to properly maintain and calibrate them is essential for any shop looking to stay competitive.

Read on as we explore exactly what you need to know about Driver Attention Warning ADAS systems and how to ensure their proper calibration. 

Understanding Driver Attention Warning Systems

Like many ADAS systems, Driver Attention Warning systems aren’t just a single sensor. Rather, they’re made up of an integrated network of sensors and processors that actively monitor driver behavior. 

After all, they’re looking to act as an attentive co-pilot who never takes their eyes off the driver's condition.

According to the National Highway Traffic Safety Administration, drowsy driving claimed 684 lives in 2021. DAW systems are designed to intervene before fatigue becomes fatal by:

  • Monitoring driver eye movement and head position
  • Analyzing steering patterns and lane position
  • Tracking trip duration and driving behaviors
  • Providing escalating alerts when attention wavers

For repair shops, the increasing complexity of these systems presents a clear business opportunity. The global ADAS market is projected to reach 66.56 billion by 2030, with DAW systems representing a significant portion of that growth.

How Driver Attention Warning Systems Work

The technology behind DAW systems is a synthesis of information gathered from multiple sensors and processors, all of which work together to assess the driver’s attention moment by moment.

While the individual components change vehicle to vehicle, most systems utilize a combination of the following:

  1. Electric Power Steering (EPS) Sensors - These measure steering inputs to establish baseline driving patterns. This way it can detect deviations that might indicate drowsiness or distraction. 
  2. Interior Monitoring Cameras - Typically mounted near the rearview mirror, these cameras continuously track the drivers physical state such as posture or eye position.
  3. Vehicle Dynamic Sensors - Multiple sensors throughout the vehicle monitor how the vehicle is actually moving such as its position on the road, speed, and acceleration or braking patterns.

In combination, these systems look for potential driver fatigue or distraction and responds through multiple alert mechanisms:

  1. Visual Alerts - The first line of warning includes:some text
    • Dashboard warning lights
    • Driver information display messages
    • Head-up display notifications (in equipped vehicles)
  2. Auditory Warnings - If concerning behavior continues:some text
    • Distinctive warning chimes
    • Voice prompts suggesting breaks
    • Escalating alert tones
  3. Integration with Other Systems - In advanced vehicles, DAW can trigger:some text
    • Lane keeping assist activation
    • Adaptive cruise control adjustments
    • Emergency response preparation

The sophistication of intervention varies by manufacturer and model year, but all DAW systems require precise calibration to function properly. Any misalignment in sensors or cameras can compromise the entire system's effectiveness as it looks to monitor drivers in a couple of different ways.

5 Types of Driver Monitoring

Driver Attention Warning systems employ multiple monitoring methods to create a comprehensive picture of driver alertness. Understanding these different approaches is important for calibration, as each monitoring type enabled on the vehicle may require specific calibration procedures and diagnostic checks.

Eye Tracking Systems

Advanced cameras and infrared sensors track subtle changes in eye movement, blink patterns, and gaze direction. Even minor camera misalignments can significantly impact tracking accuracy. A camera offset by just a few millimeters can mean the difference between reliable monitoring and false alerts that frustrate drivers.

Steering Pattern Analysis

Through the Electric Power Steering (EPS) system, the DAW system is monitoring for  micro-corrections, sudden movements, and overall steering consistency. This integration with the EPS system means that any steering-related repairs must include DAW calibration to maintain system accuracy.

Lane Position Monitoring

Lane position monitoring works in concert with other ADAS features to track vehicle position within lane markings. What makes this particularly interesting from a repair perspective is its dual role. While primarily associated with Lane Departure Warning systems, lane position data also feeds into the DAW system's analysis of driver alertness. This interconnected nature means that calibrating one system often affects the other.

Head Position Tracking

Through the internal cameras, DAW looks for any nodding, excessive head rotation, and prolonged downward gazes that might indicate fatigue or distraction. The calibration of these sensors is particularly critical after any interior repairs, especially those involving the headliner or rearview mirror area.

Driver Attention Warning Components and Calibration Points

Since these systems rely on multiple interconnected components working in sync, understanding how they work and their calibration requirements are crucial to ensure the system continues to work.

Cameras

The heart of any DAW system is its camera network. Most manufacturers position a primary camera near the rearview mirror, often integrated with other ADAS functions like Lane Departure Warning and Forward Collision Warning. 

These cameras do far more than just capture images however. They actively process visual data to track eye movements, head position, and overall driver behavior. 

Steering sensors

Moving beyond cameras, steering angle sensors play a vital role in DAW operation. These sensors interface directly with the Electric Power Steering (EPS) system to monitor steering inputs and driver behavior patterns. 

What many technicians don't realize is that even routine procedures like wheel alignments can affect these sensors' calibration. 

A misaligned steering angle sensor might still allow the vehicle to drive normally, but it could compromise the DAW system's ability to detect erratic steering patterns that could be indicating driver fatigue.

Other sensors

Driver monitoring sensors represent another critical component requiring attention during repairs. 

These sensors, which might include infrared cameras for nighttime monitoring or specialized movement detection equipment, work in concert with the main camera system. After any interior repair work, especially involving the dashboard or rearview mirror area, these sensors need verification and potential recalibration to maintain their accuracy.

The integration requirements between these components add another layer of complexity. Modern DAW systems don't operate in isolation - they're part of a broader ADAS network that shares data and coordinates responses. 

This means that calibrating one component often requires verifying the entire system's integration. For example, when calibrating a steering angle sensor, technicians need to ensure it's properly communicating with both the DAW module and related systems like Lane Keeping Assist.

Common Calibration Requirements

Understanding when and how to calibrate Driver Attention Warning systems is crucial for maintaining their effectiveness. Here's what repair shops need to know about keeping these sophisticated systems operating correctly.

Component Replacement Calibration

When any DAW-related component is replaced, it’s important to ensure it’s calibrated according to the OEM’s specifications.

Many systems require calibration from things like windshield replacements (which often involves the forward-facing camera), rearview mirror assembly changes, and steering angle sensor updates. 

What many shops overlook is that even seemingly unrelated repairs, like bumper replacement, can affect the overall ADAS network and require DAW system verification.

Software Update Requirements

After software updates—whether manufacturer-initiated or part of regular maintenance—system calibration helps ensure all components are communicating correctly. This is particularly important when the update affects how different ADAS features interact, as DAW systems often share data with other safety features like Lane Departure Warning and Forward Collision Warning.

Integration Verification

After any repair that affects vehicle geometry (including wheel alignments, suspension work, or collision repairs) technicians should verify DAW system integration. This means checking not just the individual components but also how they work together. For example, steering angle sensor calibration must be verified alongside the driver monitoring camera to ensure accurate drowsiness detection.

System Reset Procedures

Certain repairs require a complete system reset before calibration can begin. This is especially true after battery disconnection or electrical system work. The reset procedure re-establishes baseline measurements for driver behavior monitoring and ensures the system starts fresh with accurate parameters.

Environmental Considerations

What many technicians don't realize is that proper DAW calibration requires specific environmental conditions. These include:

  • A level surface for accurate sensor alignment
  • Controlled lighting for camera calibration
  • Stable temperature conditions for sensor operation
  • Clean, properly maintained sensors and cameras

For repair shops, understanding these calibration requirements is an important part of protecting both their customers and their business. Proper documentation of all calibration procedures provides liability protection and helps ensure customer satisfaction.

Maintenance and Troubleshooting

Maintaining Driver Attention Warning systems requires a systematic approach to both preventive care and problem resolution. For repair shops, developing a comprehensive maintenance protocol is essential for ensuring customer satisfaction and safety.

Preventive Maintenance Protocols

Effective DAW system maintenance starts with regular system checks. These checks go beyond simple diagnostic scans, requiring physical inspection of cameras and sensors for clarity and proper positioning. Even small debris on a camera lens can compromise system performance. Most manufacturers recommend quarterly inspections of all DAW components, with particular attention to the forward-facing cameras and interior monitoring systems.

Common Issues and Root Causes

DAW systems typically exhibit several common problems that shops should be prepared to address:

  1. False Alerts: When drivers complain about receiving warnings despite being alert, the issue often traces back to misaligned cameras or uncalibrated steering sensors. These are particularly important to fix as they can lead to drivers ignoring legitimate warnings.
  2. System Non-Response: If the DAW system fails to activate or provide warnings, the problem typically stems from either software issues or sensor blockage. Environmental factors like extreme temperatures can also affect system performance.
  3. Inconsistent Performance: If the system is finicky, it often indicates integration problems between different ADAS components. This requires a deeper dive into diagnosing rather than focusing on individual components.

Resolution Strategies

Addressing DAW issues effectively requires a methodical approach:

  1. Start with a complete system scan to identify any stored trouble codes
  2. Perform physical inspection of all components, including cleaning cameras and sensors
  3. Verify software versions and update as needed
  4. Check calibration status of all related systems
  5. Conduct road tests under various conditions to verify proper operation

Driver Attention Warning Calibration Procedures

Proper calibration of Driver Attention Warning systems begins with a crucial first step: identifying the exact requirements for each specific vehicle. While many shops excel at performing calibrations, the real challenge lies in knowing precisely what procedures are required for each make and model.

Service manuals might provide basic procedures, but often lack the specific details needed for newer models. Technical service bulletins might update certain requirements, but finding and interpreting these updates takes valuable time. This is where having access to current, comprehensive calibration information becomes crucial.

Revv addresses this challenge by consolidating manufacturer-specific calibration requirements into easily accessible formats. By simply integrating the shop's estimating system with Revv, uploading a collision estimate, or inputting a VIN Revv will identify the exact ADAS components installed on the vehicle. This eliminates the guesswork and ensures that no components are missed.

If you’re looking for instant access to detailed calibration procedures or streamline your existing ADAS calibration process, book a call with one of our experts today.

Author: Revv Editorial
Author: Bryan Grover