Capacitive device for detecting the presence of a person close to or in contact with a component of a motor vehicle

A capacitive detection device for detecting the presence of a person close to or in contact with a component of a motor vehicle, provided with a capacitive sensor, said device comprising

• at least one electrode of the capacitive sensor,
• a voltage source arranged to supply an alternating voltage,
• a device for measuring a complex value, corresponding to an impedance or an admittance, between said electrode and an electrical circuit reference point;
• a calibration resistor for calibrating the measurement of a complex value of impedance or admittance;
• characterized in that
• said capacitive detection device comprises a switching device arranged to
• connect the voltage source to said electrode, in measurement mode,
• connect the voltage source to the calibration resistor and disconnect said electrode from the voltage source, in calibration mode,
• and the measuring device is arranged to
• measure a first complex value of the calibration resistor, during operation in calibration mode;
• measure a second complex value between said electrode and said electrical circuit reference point, during operation in measurement mode, and
• correct the second measured complex value based on the first measured complex value.