Gentherm Incorporated
Capacitive sensing and heating system for steering wheels or seats to sense presence of hand of occupant on steering wheel or occupant in seat

Abstract:

A capacitance measuring system detecting an occupant of a vehicle. A sensor/heater assembly is arranged in at least one of a seat or a steering wheel of a vehicle and includes a sensor and a heater arranged adjacent to the sensor. A measurement circuit is configured to output an excitation signal to the measurement circuit and the sensor/heater assembly, measure a resonant frequency of the measurement circuit and the sensor/heater assembly in response to the excitation signal; determine at least one capacitance value based on the resonant frequency; and determine whether a body part is in proximity to the sensor based on the at least one capacitance value.