Abstract: An occupant classification system classifies occupants on a vehicle seat and is capable of separating child seats from adults during wet seat cases. In the system, the seat structure is grounded. The classification system includes a measurement circuit, an identifying circuit, and a controller. The measurement circuit is configured to measure in-phase and quadrature components of a current sent out to the sensing element. The identifying circuit is configured to identify if a seat pan and a seat back frame of the vehicle seat are grounded to a circuit ground. The controller is configured to use measurements of the measurement circuit to classify the occupant. The sensing element can be located in a sensing mat that further includes a heating element.

Abstract: The disclosed capacitance sensing apparatus may be used in an occupant classification system. The sensing apparatus may comprise a sensor pad, a sensing element disposed on the sensor pad for sensing capacitive current, at least one additional electronic element disposed on the sensor pad for providing information related to another parameter, and a switching mechanism. The switching mechanism may electrically connect the at least one additional electronic element to the sensing element during the capacitance measurements and electrically disconnect the at least one additional electronic element from the sensing element after the capacitance measurement.

Abstract: The disclosed capacitance sensing apparatus may be used in an occupant classification system. The sensing apparatus may comprise a sensor pad, a sensing element disposed on the sensor pad for sensing capacitive current, at least one additional electronic element disposed on the sensor pad for providing information related to another parameter, and a switching mechanism. The switching mechanism may electrically connect the at least one additional electronic element to the sensing element during the capacitance measurements and electrically disconnect the at least one additional electronic element from the sensing element after the capacitance measurement.

Abstract: An occupant classification system classifies occupants on a vehicle seat and is capable of separating child seats from adults during wet seat cases. In the system, the seat structure is grounded. The classification system includes a measurement circuit, an identifying circuit, and a controller. The measurement circuit is configured to measure in-phase and quadrature components of a current sent out to the sensing element. The identifying circuit is configured to identify if a seat pan and a seat back frame of the vehicle seat are grounded to a circuit ground. The controller is configured to use measurements of the measurement circuit to classify the occupant. The sensing element can be located in a sensing mat that further includes a heating element.