• ADAS
• ACC
• ABS
• ALC
• AEB
• AES
• APA
• BSM
• CAS
• DDD
• DMS
• Efficiency Assist
• ESC
• Exit Warning
• FCW
• FCTA
• LCA
• LDW
• LKA
• RCTA
• TSR

Driver Monitoring System

A driver monitoring system is a safety feature in modern cars that uses sensors and cameras to monitor the driver's behavior and attention while driving.

Driver Monitoring Systems (DMS) are designed to enhance safety by detecting signs of driver fatigue, distraction, or impairment, and providing alerts or interventions to prevent accidents.

How is it detected

Driver monitoring systems can vary depending on the car model and the type of sensors used. Common features include:

Eye Tracking

This feature uses a camera to track the driver’s eye movements and detect signs of drowsiness or distraction. If the system detects that the driver is not paying attention to the road, it provides an alert to refocus their attention on driving.

Steering Wheel Sensors

These sensors detect if the driver is holding the steering wheel and making appropriate inputs. There are three types of sensors used

• Capacitive Sensors: These are commonly used in modern steering wheels, particularly in advanced driver-assistance systems (ADAS). Capacitive sensors detect the presence of a driver’s hands by measuring electrical capacitance, which changes when hands touch the wheel. They’re typically placed around the rim of the wheel to ensure contact is monitored continuously.
• Pressure Sensors: Pressure sensors detect physical force or grip on the wheel, which can confirm if the driver is actively holding it. These sensors are often used for safety systems, where actively gripping the wheel may be required for certain maneuvers or alerts.
• Torque Sensors: While not specifically for touch detection, torque sensors detect the amount of force applied to the wheel. They can help infer driver engagement by measuring how much effort the driver is using, indirectly confirming if they are holding the wheel.

How does it work

While the specifics of Driver Monitoring Systems (DMS) can vary between manufacturers and models, they generally follow a similar operational pattern.

1. Initial Warning and Gentle Alerts

When the Driver Monitoring System first detects signs of driver inattention—like closed eyes, a diverted gaze, or a lack of hand pressure on the steering wheel—it issues an initial alert. These warnings are generally subtle and designed to gently prompt the driver to refocus:

• Audible Alerts: A soft chime or alert sound is triggered. The tone is distinct enough to catch the driver’s attention without startling them.
• Visual Cues: The instrument cluster or heads-up display shows a warning icon or message, such as “Stay Alert” or “Eyes on the Road.”
• Steering Wheel Vibrations: In some models, a brief vibration of the steering wheel serves as a tactile reminder for the driver.

At this stage, the goal is to provide the driver with a mild nudge to restore focus without significant intervention.

2. Escalating Alerts and Progressive Warnings

If the driver does not respond to the initial alerts, the DMS escalates its response with more intensive warnings. Recognizing that a lack of response may indicate a serious issue, the system intensifies its approach:

• Increased Volume and Frequency of Audible Alerts: The chimes may increase in volume and repeat at shorter intervals, making it harder for the driver to ignore.
• Stronger Steering Wheel Vibrations: If the vehicle is equipped with haptic feedback, the intensity of steering wheel vibrations may increase.
• Repetitive Visual Warnings: The dashboard or heads-up display may now display a more urgent message, like “Driver Not Responding” or “Wake Up Immediately.”

These escalating alerts are designed to be persistent and disruptive, prioritizing the driver’s attention over other in-vehicle activities.

3. Intervention Through Lane Assistance and Speed Reduction

If the driver still does not respond, the DMS assumes that the driver may be incapacitated. At this critical stage, the system shifts from alerts to physical intervention to minimize risks to the driver and others on the road. Here’s how this phase typically unfolds:

• Lane Keeping Assistance: The vehicle’s lane-keeping system, if available, activates to ensure the car remains safely within its lane, reducing the chance of lane departure accidents.
• Automated Speed Reduction: The system gradually reduces the vehicle’s speed, potentially setting it to a low cruising speed or preparing for a controlled stop.
• Emergency Hazard Lights Activation: To alert surrounding drivers, the car’s hazard lights may activate, signaling an issue with the vehicle.

During this phase, the system takes over limited control, focusing on keeping the vehicle in a stable and predictable state to reduce the likelihood of an accident.

4. Full Vehicle Takeover and Controlled Stop

If the driver still does not regain control, the DMS initiates a fail-safe procedure to bring the vehicle to a complete stop. In collaboration with the vehicle’s Advanced Driver Assistance Systems (ADAS), this step is designed to minimize risk and ensure the vehicle is safely out of traffic flow.

• Gradual Deceleration to Stop: The system progressively slows the vehicle down. Some systems bring the car to a stop in its lane, while others, when possible, guide the vehicle toward the road’s shoulder or another safe area.
• Brake Engagement: The car’s braking system activates to stop the vehicle fully and hold it in place until the driver or emergency responders intervene.
• Enhanced Hazard Signaling: The hazard lights continue to flash, and in some models, the horn may sound intermittently to attract attention from nearby drivers or pedestrians.
• Unlocking doors: On some models the system will unlock the doors to facilitate access for emergency responders or others that can help driver.

In this phase, the DMS has transitioned to complete control of the vehicle to ensure safety, taking the steps necessary to reduce risks to both the vehicle’s occupants and surrounding drivers.

5. Post-Incident and Emergency Protocols

Once the vehicle is safely stationary, the system may take additional steps to address potential emergencies:

• Emergency Call Activation (eCall): Some systems are equipped to automatically contact emergency services, providing location information and alerting them of a potential medical emergency or driver incapacitation.
• Vehicle Lockout: To prevent unintended movement, the system may activate a lockout that prevents the car from being driven until a designated authority, such as emergency personnel or a registered user, reactivates it.
• Continuous Monitoring Until Response: Even after the vehicle has stopped, the DMS continues to monitor for signs of driver response. Any movement, such as blinking or head turning, may reset the system and allow the driver to regain control if they’ve recovered.

Real World Examples

The YouTube channel, Out of Spec Reviews, is known for conducting real-world tests of Driver Monitoring Systems (DMS). Below are some examples:

Example 1: Porsche Macan EV

In this example, the Macan EV demonstrates its ability to stop the car, unlock the doors, turn on the interior lights, and call for help. This showcases a highly effective DMS.

Example 2: Hyundai IONIQ 6

In this example, the IONIQ 6 disables lane centering assist when it does not receive any response from the driver and continues to drive off the road at full speed. This highlights a significant shortcoming in its DMS.

Example 3: Mercedes EQS

In this example, the Mercedes EQS stops the car in its lane when the driver is unresponsive, demonstrating a reliable DMS.