How are sensors in driver monitoring systems changing?

Government regulations, such as European Union (EU) General Safety Regulations and various New Car Assessment Programs (NCAP) requiring driver monitoring system (DMS) and the U.S. Federal Communications Commission (FCC) mandating child presence detection (CPD) systems in new cars, are incentivizing car makers and system suppliers to add more sophisticated sensors inside of new vehicles. The type of sensing performed, the location of the sensors, and other criteria differentiate a company’s solution in satisfying regulations and distinguishing its product offerings to consumers.

Traditional DMS solutions have relied on passive technologies, such as lane-keeping and driving duration, to gather information about the driver from the vehicle as well as input from steering sensors. However, these passive approaches can be inaccurate, providing a high incidence of false positives.

With the EU General Safety Regulation mandating that all newly manufactured vehicles falling under categories M and N incorporate an advanced driver distraction warning system (ADDW) after mid-2024, actively monitoring the driver’s eye movement could dictate a transition from passive to vision-based active technology. Focusing on the driver, a dashboard, A pillar, or a steering column mounted camera with appropriate software can analyze several different situations, including:

Activity detection — detect whether the driver is focused on driving or not.
Body posture — track how the driver is sitting, moving, or interacting with objects in the vehicle.
Facial expression analysis — examine the driver’s facial expressions to determine their mood, emotions, and behaviors.
Health status — identify the driver’s health status by analyzing body posture and eye, head, and face movements.

One of the more subtle and perhaps least obvious locations for monitoring the driver is the rearview mirror. One supplier offers a mirror-integrated DMS to track the driver. The driver’s head position, eye gaze, and other metrics are analyzed to determine distraction, drowsiness, sudden sickness, and other situations. For semi-autonomous vehicles, the return of manual control could be initiated. The supplier can expand the system to include 2D and 3D cabin monitoring, enabling detection of passengers, behavior, objects, and even the presence of life.

Avoiding left behinds

The incidence of small children and even pets being forgotten and left in vehicles, which can be overcome by excessive heat, has prompted regulators, such as the FCC, to require child presence detection (CPD) systems in all new cars by 2025.

One company’s solution uses 60-GHz band radar. With an antenna array consisting of 2 to 4 transmission (Tx) and 3 to 4 reception (Rx) channels, the system can cover up to two rows with one radar signal. Based on a radar point cloud image, advanced computer vision algorithms can detect the presence of living beings (such as children or pets) even when they are not visible, such as a child hidden under a blanket.

Another company’s approach uses an ultra-wideband (UWB) impulse radar transceiver System on Chip (SoC) that integrates two 7.875-GHz transmitters for unlicensed operation in worldwide markets. The SoC also has two direct RF-sampling receivers, advanced power management functions, and on-chip signal processing.