Occupant detection

Headlight control

Image sensors and infrared light sources are used in occupant detection systems to detect and monitor occupants in terms of their position in the seat, or the driver’s activity or fatigue.

With the variety of airbags used in cars today, this feature is important to ensure the best possible protection for each occupant. The airbag control unit decides in the case of an accident, if it is helpful to deploy the airbags and with which level of force, or if there is a higher probability to cause severe injury to a passenger.

This decision is made based on the detected conditions such as location and size of a passenger and their distance to the airbag. An unfavorable seating position of the co-driver, or an infant in a child car seat in the front could be examples where the system decides not to deploy an airbag.

As airbags are one-time use only and have to be replaced in the garage after deployment, this system also helps to save money. It avoids unnecessary airbag deployment, for example, in seats where there are no passengers and therefore avoids the need to replace them.

Besides airbags, occupant detection and monitoring is also necessary for other advanced driver assistance systems (ADAS). Some cars, for example, use seat-belt tightening as a pre-crash safety measure in the case of an accident, which requires occupant information. In addition, fatigue detection can be performed by monitoring eye movements and blinking frequency using a camera. Monitoring the driver’s activity becomes an important topic when considering the future direction to automated driving, as the driver will be allowed to do other things besides the actual driving task, such as reading or working with a tablet. It is therefore crucial that the take over time from automated driving mode to manual driving will be short enough, in case of an emergency situation, if the system is not completely autonomous.

Our TOF CMOS sensor works with an indirect time of flight (TOF) measurement as a 3D sensor. It can therefore deliver the information about the occupants’ position or about the driver’s activity or fatigue. An infrared laser diode or LED, or an array of these, is used as active illumination and sends out short light pulses. The CMOS sensor determines the time of flight of the reflected, incident light with each of its pixels, creating a 3D picture. This CMOS sensor is a special, high-speed charge transfer device, which is essential to measure short distances. The light pulse travels with a high speed of 3*108 m/s to the object and back. The closer the object, the shorter is the time of flight. Therefore the detector must be able to do the whole measurement within several nanoseconds.

Operating Temperature In special SMD package -40°C to + 125°C
Special plastic mold devices -40°C to +105°C
Customization possible, please contact us for further information
Scroll to Top