Trw Vehicle Safety Systems Inc.

Joseph E Mazur

Brian K Blackburn

Scott B Gentry

Charles E Steffens, Jr

Louis R Brown

An apparatus (47) determines presence, type, and a size value of a vehicle occupant (14) located within a vehicle (12). A first capacitive sensor (46A) is located on a first side of an occupant location within the vehicle (12) and senses a first capacitance value. An associated drive/monitor circuit (42A) provides a first signal (44A) indicative of the first capacitance value. A controller (27) determines from the first signal (44A) whether the first capacitance value is indicative of an occupant located proximate to the first capacitive sensor (46A). The controller (27) determines a first distance between the first capacitive sensor (46A) and the occupant (14) using the first signal (44A). A second capacitive sensor (46C) is located on a second side of the occupant location and senses a second capacitance value. An associated drive/monitor circuit (42C) provides a second signal (44C) indicative of the second capacitance value. The controller (27) determines from the second signal (44C) whether the second capacitance value is indicative of an occupant located proximate to the second capacitive sensor (46C). The controller (27) determines a second distance between the second capacitive sensor (46C) and the occupant using the second signal (44C). The controller (27) determines from at least one of the first and second signals (44A and 44C) whether the occupant type is a child in a child seat. The controller (27) determines a size value of the occupant using the first and second determined distances.

Apparatus and method for discerning certain occupant characteristics

A vehicle seat belt retractor system (10) includes two seats (16, 18) each having its own integrated seat belt webbing retractor (60, 112). Each retractor (60, 112) includes a locking assembly (76, 80) for blocking belt withdrawal in response to an electrical signal. At a central location in the vehicle spaced from the seats (16, 18), a sensor (24) is disposed for sensing vehicle deceleration exceeding a predetermined deceleration and for providing a control signal indicative thereof. An RF transmitter (42) is electrically connected with the sensor (24) and is actuatable in response to the control signal to transmit an RF signal. An RF receiver (100, 114) on each vehicle seat (16, 18) receives the RF signal and provides an output signal to actuate the locking assembly (76, 80) of the two seat belt retractors (60, 112). Each vehicle seat (16, 18) also has (a) a battery (98) for supplying electric power to actuate the locking assembly (76, 80) of the retractors (60, 112) and (b) a piezoelectric member (90) responsive to an occupant sitting on the seat for generating an electric current to charge the battery (96). In a second embodiment, a separate deceleration sensor (24a) is mounted on each vehicle seat for electrically actuating its associated retractor. In a third embodiment, the transmitted signal provides the power for actuating a vehicle occupant restraint (178).

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Washington, MI, United States of America

Joseph E Mazur