Abstract: An occupant detection system and method that uses an isolation assembly to isolate electrically a power supply providing power to a heater element for heating a vehicle seat from a sensing circuit that uses the heater element as an electrode for electric field or capacitance type occupant detection. The isolation assembly includes a common mode choke that by itself provides sufficient isolation when the sensing circuit excitation signal frequency is high enough, and provides switches that infrequently interrupt electrical power to the heater element so a humidity level can be determined using a relatively low excitation signal frequency. Knowing the humidity level is desirable to adjust a threshold use to determine if the sensing circuit indicates that the seat is empty, or is occupied.

Abstract: An occupant detection system and method that uses an isolation assembly to isolate electrically a power supply providing power to a heater element for heating a vehicle seat from a sensing circuit that uses the heater element as an electrode for electric field or capacitance type occupant detection. The isolation assembly includes a common mode choke that by itself provides sufficient isolation when the sensing circuit excitation signal frequency is high enough, and provides switches that infrequently interrupt electrical power to the heater element so a humidity level can be determined using a relatively low excitation signal frequency. Knowing the humidity level is desirable to adjust a threshold use to determine if the sensing circuit indicates that the seat is empty, or is occupied.

Abstract: A capacitive sensing apparatus for a vehicle seat includes a deflectable dielectric mat and a flexible printed circuit that wraps around the major surfaces of the dielectric mat to define upper and lower conductor strips that overlap in a direction perpendicular to the dielectric mat. Overlapping regions of the conductor strips define an array of capacitive load cells distributed over the seating surface. A connector stub depending from the flexible printed circuit couples the conductor strips to an external circuit that measures the capacitance of the various load cells to determine occupant weight and weight distribution.

Abstract: A capacitive sensing apparatus for a vehicle seat includes a deflectable dielectric mat and a flexible printed circuit that wraps around the major surfaces of the dielectric mat to define upper and lower conductor strips that overlap in a direction perpendicular to the dielectric mat. Overlapping regions of the conductor strips define an array of capacitive load cells distributed over the seating surface. A connector stub depending from the flexible printed circuit couples the conductor strips to an external circuit that measures the capacitance of the various load cells to determine occupant weight and weight distribution.