Driver Monitoring Systems

Driver Monitoring Systems (DMS) combines various technologies to analyse and monitor driver behaviour and fitness to operate a vehicle safely. This includes Driver Drowsiness Detection, Advanced Driver Distraction Warning (ADDW) Systems, and Driver State Monitoring. Specifically, the goal is to identify any drop in the driver’s attentiveness or signs of drowsiness. When needed, DMS will alert the driver with warnings to refocus or take a break. As part of ADAS, some semi-autonomous cars can brake or use autonomous steering if the driver doesn’t react to warnings.

How Does It Work?

The primary tool of DMS is a driver-facing camera fixed on the steering wheel column or elsewhere on the dashboard. This camera must capture the driver’s face even under the most challenging lighting conditions. To achieve it, DMS uses infrared (IR) illumination that’s invisible to the human eye, so it doesn’t distract the driver. By using IR lighting, the IR-sensitive DMS camera can capture clear images of the driver’s face, even in low light or at night. The camera monitors the driver’s face, eyes, mouth, and head position in real-time to assess driver behaviour and attentiveness.

Typically, DMS requires baseline information from the driver to work effectively. To establish this baseline, DMS must capture the driver’s facial features during normal, attentive driving conditions. With the baseline set, the DMS can use it to identify the driver before each drive. This identification process involves comparing the person behind the wheel with available driver profiles, relying on facial or biometric recognition for identification. The system can then configure monitoring based on the driver’s recognised characteristics. On top of that, some systems can recall and adjust to the driver’s preferred settings, such as mirrors and seats.

What Does it Track?

When the camera captures the driver’s eyes, facial features, and head pose, AI compares the real-time information with the baseline to assess the driver’s fitness to drive. DMS tracks the driver’s eye movement, the frequency of blinking, and the openness of their eyelids. An increase in blinking frequency or longer periods of closed eyes can indicate drowsiness. Additionally, monitoring heart rate and facial expressions for signs of stress can also be important, as it could affect driving.

The camera watches for nodding, yawning, and episodes of microsleep; microsleep episodes are brief, involuntary eye closures that occur for less than three seconds. Some DMS can also measure pupil size to detect drowsiness or an impaired state. Pupil diameter, breathing rhythm, or even the driver’s speech pattern can show driving under the influence. Additionally, monitoring the driver’s lane-keeping discipline and steering input provides valuable data that may indicate drowsiness and/or distraction.

DMS analyses the driver’s head position and gaze direction to see if they are actually focused on the road. Monitoring a driver’s head and eye movements, along with the frequency of these movements, can indicate if they are distracted while driving. A distracted driver isn’t focused on the road but rather on other activities (e.g., using a mobile phone, adjusting the radio, daydreaming, etc.).

EU Legislation

EU Delegated Regulation 2021/1341 requires all new vehicle types to have driver drowsiness and attention warning (DDAW) systems starting July 6, 2022. From July 7, 2024, and onwards, all vehicles registered for the first time must have DDAW systems onboard.