The PPS is a support function for the seat belt and driving behavior feedback. The detection of
passengers complements the seat belt detection system to recognize passenger seating positions and
factor in non-compliance.
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OEMs already use passenger detection technology (pressure sensors integrated into vehicle seats) to
determine passenger presence for air bag deployment functions. This type of detection and
information may be available for use with seat belt compliance, speed monitoring, and excessive
maneuver algorithms. For example, the number of passengers and their seat belt use can be
integrated into checking teen GDL requirements and compliance. For the OEM systems, the
interface for this subsystem should be “invisible” to the driver and passengers except at vehicle
start-up as a status check.
For the demonstration vehicle and initial FOT testing, a passive infrared (PIR) system was mounted
beneath each passenger seat to detect heat signatures from occupants’ legs. This implementation was
a compromise from the OEM version. Other compromises included displaying passenger presence
as an indication of subsystem status.
For the FOT implementation, an additional challenge was that the system had to be incorporated
into a variety of different vehicles. General requirements for the FOT tests included low power
consumption, not marring the participant’s vehicle, and keeping the system inconspicuous. The
subsystem evaluation provided valuable input for the FOT about reliability and passenger detection
and changes were instituted based on this information.
Finally, the PPS is necessary for input into the SBDRS and allows increased functionality for the
speed monitoring and feedback subsystem and excessive maneuver and feedback subsystem by
providing a valuable contextual factor (e.g., passenger presence).