Iee International Electronics and Engineering S.a.

Mesa Imaging Ag

Lee International Electronics & Engineering S.a.

Laurent Lamesch

Michael Puetz

Michael Virnich

Thomas Faber

Thomas Meyers

David Hoyer

Christoph Wendt

Michael Pütz

Aloyse Schoos

Frank Althaus

Martin Thinnes

Thomas Stifter

Jochen Landwehr

Baptiste Anti

Andreas Fox

Laurent Federspiel

Andreas Petereit

Yves Decoster

Pierre Orlewski

Gianluca Favalli

Tobias Justinger

Thierry Oggier

Bruno Mirbach

Patrick Di Mario Cola

Felix Lustenberger

Dimitri Tatarinov

Claude Watgen

Erik Holzapfel

Guido Becker

Christian Urig

Heinrich Gierens

Alan Koehler

Una Karahasanovic

Oliver Lion

Roberto Orsello

Patrick Di Mario-Cola

Laurent Vanstraelen

Bernd Farsch

Bertrand Rue

Attila Konfar

Tobias Pampel

Johnny Lorang

Daniel Ferring

Marie-Astrid Cauquy

Christophe Keiser

Micheal Puetz

Muhammad-Zeeshan Khan

Laurent Thiry

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.

Low-cost, high measurement speed capacitive sensing circuit for loading mode operation of capacitive sensors

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. Based on the determined position or positions, a hand or body part positioning on the object is determined.

TDR-based system for hand or body part positioning detection on an object, particularly on a steering wheel

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.

Sensor arrangement for capacitive position detection of an object

An impedance measurement circuit for determining a complex impedance of a capacitive sensor that is configured for employing at least one electric heater member as an electrode to be operated in loading mode. The measurement circuit includes: a signal generating unit for providing an electric measurement signal; a signal sensing circuit measuring current through the at least one electric heater member; an electric heater member connection circuit comprising a plurality of MOSFETs for selectively electrically connecting the electric heater member either to the signal sensing circuit for complex impedance measurement or to a DC electric power unit for heating purposes; and a control and evaluation unit that is configured for controlling a switching status of the plurality of MOSFETs according to a predefined sequence, and for determining a complex impedance from the determined currents with reference to a complex reference potential during predefined stages of the predefined sequence.

Low-cost, protected capacitive sensing circuit for loading mode operation of capacitive sensors employing heater members

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.

TDR-based system for detection of hand touch positionings on an object, particularly on a steering wheel for the purpose of hand gesture recognition

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.

Multi-channel capacitance sensing measurement circuit

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.

TDR-based system and method for hand detection on a steering wheel with elimination of aging and environmental effects

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. The method includes, for each predefined signal frequency: determining statistical quantities and signal parameters regarding a number of determined momentary values of an unknown complex impedance; eliminating portions up to a predefined hand touch movement lower limit frequency and from a predefined high-frequency limit down to a predefined hand touch movement upper limit frequency; excluding statistical outliers from determined momentary values; and using an eliminated frequency portion for calculating a momentary reference value for the unknown complex impedance.

Robust 'hands on steering wheel' classification based on a relative measurement system

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.

System for capacitive object detection

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.

Capacitive sensor arrangement

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.

System for grounding and diagnostics

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.

Sensor arrangement for capacitive position detection of a hand on a steering wheel

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.

Robust, low-cost capacitive measurement system

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.

Capacitive sensor system

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.

System for hand detection on a steering wheel

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Reichlange, Luxembourg

Laurent Lamesch