Abstract: An impedance measurement circuit for determining a complex impedance of a capacitive sensor having at least one sense electrode operable in loading mode and at least one guard electrode. The measurement circuit includes: a pulse generator unit for providing a periodic electric measurement signal and a periodic electric guard signal; a signal sensing circuit for sensing a sense current flowing through the at least one sense electrode or the sense electrodes in response to the pulse generator unit measurement signal; and a control and evaluation unit. The control and evaluation unit is configured for determining a complex impedance from the determined sense currents with reference to a complex reference potential.

Abstract: A method of operating a capacitive sensing device that includes a capacitive sensor having at least one sense electrode, a measurement signal source for providing an alternating electric measurement signal with at least three fixed predefined signal frequencies to the at least one sense electrode, and an impedance measurement circuit for determining an unknown complex impedance of the at least one sense electrode from a response to the provided electric measurement signal.

Abstract: A system for capacitive object detection. In order to provide means for efficiently using the circuitry of an electrical heating device for capacitive object detection, the system includes: an elongate conductive element extending between a first terminal and a second terminal, wherein the first terminal is coupled to ground via a capacitive element and is connectable to an electrical power source, and the second terminal is connected to ground; and a detection circuit connected to at least one detection node disposed on the conductive element between the first and second terminal. The detection circuit is adapted to capacitively detect the presence of an object in the proximity of the conductive element based on an impedance associated with the object.

Abstract: A method of detecting a hand positioning on a steering wheel using a sensing system having an electrically conducting signal line on a rim of the steering wheel with a priori knowledge about a relation between a distance of any portion of the signal line from a reference point and information on a position on the rim, and which further includes an electric impedance change of predefined magnitude that is permanently arranged at a predefined position along the signal line, a signal voltage source, and a control and evaluation unit. From a received measurement signal traveling along the signal line and having been reflected by the electric impedance change and by another portion or portions of the signal line, a reference travel time is determined. A position or positions on the rim of the other portion or portions of the signal line can then be determined.

Abstract: A sensing system and method of recognizing a hand gesture established by a sequence of hand touch positionings on an object. The method includes at least steps of: providing to a signal line a time-dependent measurement signal; receiving the measurement signal after being at least partially reflected by at least one portion of the signal line; determining positions on the object of the portions of the signal line that have reflected the measurement signal; comparing an obtained plurality of stored successively determined positions on the object with at least one predefined pattern of successive positions to derive a measure of similarity; and providing an output signal that is indicative of the predefined pattern of successive positions if the derived measure of similarity is lower than a predefined threshold value.

Abstract: A sensing system for hand or body part positioning detection on an object, particularly on a rim of a steering wheel, includes at least one electrically conducting signal line that is arrangeable on a surface of the object with a priori knowledge about a relation between a distance of any portion of the at least one signal line from a reference point and information on a position on the object, a signal voltage source for providing a time-dependent measurement signal to be traveling along the signal line, and a control and evaluation unit. From a received reflected measurement signal, the control and evaluation unit determines a position or positions on the object of a portion or portions of the signal line at least partially reflecting the measurement signal.

Abstract: A sensor arrangement for capacitive detection of an object, including: an electrode arrangement having a heating element as an electrode; a detection device providing a detection signal to a sensor electrode and capacitively detecting the presence of an object near the sensor electrode; a high-side switch connected between a heating power source having a first potential and the heating element; a low-side switch connected between the heating element and a second potential; and a gate controller closing the high-side switch and low-side switch in a heating mode and opening the high-side switch and low-side switch in a detection mode. A decoupling MOSFET is connected between the high-side switch and heating element. The gate controller closes the MOSFET in the heating mode and opens the MOSFET in the detection mode. During the detection mode, the decoupling circuit provides a third potential at a first node between the high-side switch and MOSFET.

Abstract: A capacitive sensor arrangement includes a sensing electrode having a capacitance (Cx) which depends on the presence of an object in a detection space; a measurement device connected to the sensing electrode and configured to detect the capacitance (Cx) of the sensing electrode; and a conducting structure, wherein the capacitance (Cx) of the sensing electrode depends on a potential of the conducting structure. In order to obtain a reliable capacitive measurement, the measurement device is connected to a power supply between a first potential (Vs) and a second potential (GND), the measurement device being connected to the second potential exclusively via the structure.

Abstract: A system for grounding and diagnostics, including a conductive frame for mounting a capacitive sensor. In order to provide a means for ensuring and monitoring a grounded condition of a conductive frame, the system further includes a diagnostics circuit, by which the frame is AC grounded and which has an electric source connected to the frame via a first line and adapted to apply a diagnose signal to the frame via the first line, the diagnostics circuit being connected to the frame by a second line and being adapted to provide at least one quantity that depends on the diagnose signal and on a ground connection of the frame.

Abstract: A capacitance measurement circuit for determining complex electric currents in a multi-channel capacitive sensing device includes a first sensing circuit for selectively connecting one of a plurality of sense electrodes to a common sense node and for connecting a corresponding guard electrode of the sense electrode to a common guard node, and at least a second sensing circuit. A measurement signal voltage source provides an alternating measurement voltage to the common guard node in a remotely controllable manner. A diagnostic signal voltage source provides an alternating diagnostic voltage to the common guard node in a remotely controllable manner. A current measurement circuit is connected with a signal input port to the common sense node and with a reference input port to the output port of the measurement signal voltage source.

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 system for capacitive object detection. In order to provide means for efficiently using the circuitry of an electrical heating device for capacitive object detection, the system includes: an elongate conductive element extending between a first terminal and a second terminal, wherein the first terminal is coupled to ground via a capacitive element and is connectable to an electrical power source, and the second terminal is connected to ground; and a detection circuit connected to at least one detection node disposed on the conductive element between the first and second terminal. The detection circuit is adapted to capacitively detect the presence of an object in the proximity of the conductive element based on an impedance associated with the object.

Abstract: A complex current measurement circuit for a guard-sense capacitive sensor includes a periodic signal voltage source, a differential transimpedance amplifier circuit (DTA) and a demultiplexer circuit (DMX). At least one sense antenna electrode of the capacitive sensor is electrically connectable to a signal input line of the DMX which has signal output lines electrically connected to differential signal input lines of the DTA. The DTA includes operational amplifiers having input ports each electrically connected to one of the signal output lines. For each differential signal input line, either a capacitor is electrically connected between an output port of the voltage source and the differential signal input line, wherein an impedance of the capacitor is close to zero Ohm, or a galvanic connection is provided to one of the signal output lines. An output signal provided by the DTA is usable for determining a complex sense current of the capacitive sensor.

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 capacitive sensor system that includes: a sensor arrangement with a plurality of capacitive electrodes, each being connected to a corresponding detector line; and a detector device connected to each detector line and configured to detect the capacitance of each electrode by applying a detector signal. The sensor arrangement includes: at least one electrode group having at least two electrodes, each electrode of an electrode group being connected to another electrode via a resistive element so that all electrodes of this electrode group are connected in series; and a diagnose device that is connected, for each electrode group, at least to a first detector line of a first electrode and to a second detector line of a second detector electrode and is configured to apply a diagnose signal via the first and second detector lines and to detect a conductor break based on a response to the diagnose signal.

Abstract: A system for hand detection on a steering wheel includes a signal line extending from a first point to a second point and being disposed along at least a portion of a surface of the steering wheel; and a detection unit coupled to the first point. The detection unit is configured to send a time-dependent detection signal over the signal line, receive a reflected signal from the signal line and detect the presence of a hand on the surface based on the reflected signal.

Abstract: A camera system includes an imager unit for recording image data and converting the image data into a digital image signal, and a video processing unit operatively connected to the imager unit for receiving the digital image signal from the imager unit and for generating a corrected video output signal. The video processing unit has a dead pixel correction unit and a subsequent non-uniform offset error correction unit. The dead pixel correction unit is configured for correcting the signal of confirmed dead pixels, which are referenced in a map of confirmed dead pixels associated to the dead pixel correction unit. The non-uniform offset error correction unit is configured for correcting readout amplifier non-uniformity and pixel level non-uniformity in the digital image signal. The non-uniform offset error correction unit is further configured for new dead pixel detection simultaneously to the pixel level non-uniformity correction.

Abstract: A capacitance measurement circuit for determining a complex electric current of at least one capacitive sense-guard sensor. The circuit includes an alternating signal voltage source, wherein each guard electrode is electrically connectable to the signal voltage source, a current measurement circuit having at least one measurement channel to determine a measurement current through a sense electrode, and at least one diagnostics channel to determine, with reference to an AC ground potential, a diagnostic current flowing through a guard electrode and a sense electrode of a capacitive sensor, and a remotely controllable switching unit, which in a measurement switching state is configured to electrically connect the sense electrode of the capacitive sensor to the measurement channel, and in a diagnostic switching state is configured to electrically connect the sense electrode to the diagnostics channel.

Abstract: A measurement circuit for a capacitive measurement system includes a DC voltage source, a first switching member, a charge transfer circuit, an integration capacitor and a current sink electrically connected in parallel to the integration capacitor. The charge transfer circuit has an active semiconductor device and a direct current bias voltage source. At least one electrically conductive electrode that forms a capacitor of unknown capacitance in conjunction with a reference electrode is electrically connectable either to the DC voltage source for charging or to the charge transfer circuit for discharging into the integration capacitor. The charge transfer circuit is configured for receiving an electric input current at an input port and for giving out an electric output current at an output port that is equal to the electric input current within a predetermined range of voltages across the input port and the output port of the charge transfer circuit.

Abstract: A capacitance measurement circuit for determining a complex electric current of at least one capacitive sense-guard sensor. The circuit includes an alternating signal voltage source, wherein each guard electrode is electrically connectable to the signal voltage source, a current measurement circuit having at least one measurement channel to determine a measurement current through a sense electrode, and at least one diagnostics channel to determine, with reference to an AC ground potential, a diagnostic current flowing through a guard electrode and a sense electrode of a capacitive sensor, and a remotely controllable switching unit, which in a measurement switching state is configured to electrically connect the sense electrode of the capacitive sensor to the measurement channel, and in a diagnostic switching state is configured to electrically connect the sense electrode to the diagnostics channel.