CAPACITIVE SENSOR SYSTEM

摘要

Capacitive sensor system for a vehicle, which system comprises a signal generator, a signal detector and a processing device. The sensor system further comprises an earth antenna adapted to serving as a virtual external earth for the system, connected electrically to the signal generator and so disposed on the vehicle that it is electrically insulated from the vehicles chassis, has a predetermined size and is situated a predetermined distance from the ground surface. The system comprises at least two capacitive sensor elements which each define a detection zone and are disposed galvanically separate from the vehicles chassis, and a selector device intended to connect said capacitive sensor elements according to a predetermined detection configuration on the basis of a control signal applied to the selector device. The signal generator is adapted to generating a sensor signal with a frequency and an amplitude and to applying it between each connected capacitive sensor element and the external virtual earth, and the signal detector is adapted to detecting and determining a measure of the voltage potential between these latter and to generating a measurement signal based thereon which is conveyed to the processing device. The processing device is adapted to processing the measurement signal and conveying the processed measurement signal to an alarm system which is adapted to generating one or more alarm signals on the basis of the processed measurement signal.