Abstract: A sensor arrangement for capacitive position detection of a hand on a steering wheel. The sensor arrangement includes: a plurality of capacitive sensors disposed along a detection surface, which is an outer surface of the steering wheel, each sensor having at least one sensor electrode; and a measurement device electrically connected to the sensors. In order to increase the reliability of capacitive hand detection on a steering wheel, the measurement device is adapted to perform a sequence of detection operations, and in each detection operation, to activate at least one sensor by applying a detection signal to its at least one sensor electrode in order to capacitively detect the hand while grounding at least one other sensor by connecting at least one of its sensor electrodes to ground, and to activate different sensors in consecutive detection operations.

Abstract: A sensor arrangement for capacitive position detection of a hand on a steering wheel. The sensor arrangement includes: a plurality of capacitive sensors disposed along a detection surface, which is an outer surface of the steering wheel, each sensor having at least one sensor electrode; and a measurement device electrically connected to the sensors. In order to increase the reliability of capacitive hand detection on a steering wheel, the measurement device is adapted to perform a sequence of detection operations, and in each detection operation, to activate at least one sensor by applying a detection signal to its at least one sensor electrode in order to capacitively detect the hand while grounding at least one other sensor by connecting at least one of its sensor electrodes to ground, and to activate different sensors in consecutive detection operations.

Abstract: A method of operating a capacitive measurement system for compensation of temperature influence is described. The capacitive measurement system includes at least one capacitive sensor member in an installed state and a capacitive measurement circuit for determining a complex impedance of an unknown capacitance from a complex sense current through the at least one capacitive sensor member. In the method, a calibration measurement is carried out to obtain temperature characteristics of both the real part and the imaginary part of determined impedances. In following impedance measurements of the unknown capacitance at a current temperature, the real part and the imaginary part of the measured impedance is determined, and based on the real part determined at the current temperature and the determined temperature characteristics of both the real part and the imaginary part, the imaginary part of the impedance determined at the current temperature is corrected.