Patent ID: 6304179
Filing Date: 2001-10-16
Classification: B60R,G01S

Abstract:
A vehicle mounted ultrasonic occupant position measuring system (10) comprising:transmitter means (12) for generating a pulse modulated transmitted ultrasonic signal mounted within a passenger compartment of a vehicle;receiver means (12) mounted within the passenger compartment of the vehicle for receiving a reflection of the transmitted ultrasonic signal, the receiver means being characterized as having a Q factor less than 5;a narrow band filter (62) centered on the transmitted signal operatively connected to the receiving means for attenuating noise;an envelope detection circuit (66), operatively connected to the narrow band filter;an analog-to-digital converter (68) operatively connected to the envelope detection circuit (66);a control unit (16) which is used to activate the transmitter means (12), and receive the reflection of the transmitted signal, the control unit (16) providing a means for calculating the position of the occupant, the control unit employing a threshold requiring a lower signal strength with greater time to receive the reflection.