Iee International Electronics and Engineering S.a.

Frank Althaus

Laurent Lamesch

David Hoyer

Thomas Meyers

Erik Holzapfel

Michael Puetz

Michael Virnich

Thomas Faber

Andreas Petereit

Michael Pütz

Christoph Wendt

Stephen Fuks

Ingrid Scheckenbach

Oliver Lion

Alan Koehler

Miguel Ribeiro

Guenter Wagner

Thomas Krautheim

Alain Strasser

Andrej Mattheis

Arnaud Meurens

An electric heating and capacitive sensing arrangement that includes: an electrically conductive heating track arranged on a surface of a planar substrate, the electrically conductive track being connectable to a current source so that during a heating operation a current flows through the electrically conductive track. The electrically conductive track is connectable to a capacitive sensing circuit so that during a sensing operation a capacitive sensing signal is applied to the electrically conductive track. The electrically conductive track has at least a first and a second heating track section extending at a distance along each other on the substrate, whereby a gap is formed between the first and the second heating track section. The heating and sensing arrangement further includes a layer of electrically conductive material arranged on the surface of the substrate in the gap between the first and the second heating track section.

Electric heating and capacitive sensing arrangement and methods for manufacturing the same

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 capacitive detection device includes a capacitive sensor having a sense electrode and an auxiliary electrode that are arrangeable in the vicinity of an electric heater member for mutual capacitive coupling. The capacitive detection device has a signal voltage source providing an alternating measurement voltage, a complex impedance measurement circuit for measuring complex sense currents and for determining a complex impedance based on the measured complex sense current, and for electrically connecting the auxiliary electrode either with the reference voltage or with the guard signal. The method includes providing the measurement signal to the sense electrode and electrically connect the auxiliary electrode selectively either to the reference voltage or to the guard voltage; determining capacitance values in the two different connection states of the auxiliary electrode; and calculating a compensated capacitance value as a weighted sum of the two determined capacitance values, wherein the weighting factors are predefined constant values.

Capacitive detection and/or classification device and operation method for heater member compensation, particularly for automotive application

A method of operating a capacitive sensing device for diagnosing a galvanic connection of at least one guard electrode. The capacitive sensing device includes at least one sense-guard capacitive sensor and a capacitive measurement circuit. The sense-guard capacitive sensor includes a first electrically conductive sense electrode and a first electrically conductive guard electrode and at least a second electrically conductive sense electrode, which is galvanically separated from the first sense electrode, and at least a second electrically conductive guard electrode. Each of the guard electrodes is proximally arranged to at least one of the sense electrodes and is galvanically separated from each of the sense electrodes. The method uses a calculated difference of imaginary parts of complex sense currents resulting from coupling mode measurements between at least two of the sense electrodes for assessing a status of the galvanic connection of the guard electrodes.

Capacitive sensor guard diagnostics from redundant coupling measurement

A multi-electrode capacitive sensor is introduced to measure a spatial distribution of impedances to ground. The sensor can be used to identify the location of the highest impedance on the seating surface and can be a two-electrode sensor with a first electrode covering a central zone of a seat cushion and a second electrode with two galvanically connected electrode members, wherein each electrode member covers one side region of the seat cushion such that the first antenna electrode is arranged between the two electrode members of the second antenna electrode, or a two-electrode sensor with a left and right design. By measuring the difference of the impedance to ground between the two zones the system can get a simplified picture of the impedance distribution on the seating surface. This information can be used to distinguish between grounded structures such as (ISOFIX) child restraint systems and human occupants.

Capacitive occupant detection system with improved isofix discrimination

A capacitive seat occupancy detection and classification system with a capacitive sensor having at least two distinct antenna electrodes and a method of operating is proposed to reduce an impact of the sensor-to-object impedance Zon an object-to-ground impedance Zmeasurement that the system performs. By measuring the impedance between the different antenna electrodes by the system, additional information is obtainable that can be used to compensate the impact of the sensor-to-object impedance Zon the object-to-ground impedance. As one effect of combining both impedance measurement results, the proposed system is able to determine the object-to-ground impedance Zcompletely independent from wear of ISOFIX anchorages or human objects touching the electric ground of the vehicle, thus ensuring a stable classification of the object over the entire vehicle lifetime. The method further enables high-resolution seat occupancy classification.

Capacitive occupant detection system with improved discrimination capability

A capacitive detection device and capacitive detection system for use in a vehicle interior includes at least one electrically conductive wire, at least partially attached to a component of the vehicle interior, and at least one electrically conductive layer that is arranged in close proximity to the at least one electrically conductive wire, compared to a potential minimum distance to a vehicle occupant, wherein a galvanic connection between the at least one electrically conductive layer and the at least one electrically conductive wire is avoided.

Capacitive detection device and system for use in vehicle interior

A capacitive occupancy or proximity detector () comprises a heating circuit, an impedance measurement circuit () and a diagnostic circuit. The heating circuit includes a heating element (). The impedance measurement circuit is connected to the heating element so as to measure impedance between the heating element and a node at ground potential. The diagnostic circuit is configured for measuring electrical resistance across the heating circuit and includes a heating current sensor (), configured for sensing a heating current across the heating circuit, a current supply device () for driving a diagnostic current across the heating circuit and a current limiting ground path (), configured for draining the diagnostic current and for blocking the heating current.

Diagnostic capacitive occupancy or proximity detector

A capacitive sensor for a vehicle seat comprises an antenna electrode and a control and evaluation circuit operatively connected to the antenna electrode. The control and evaluation circuit is configured to operate in a first mode of operation, during which it measures alternating electrical current flowing between the antenna electrode and ground. The capacitive sensor comprises a seat frame connector for connecting the control and evaluation circuit to the seat frame of the vehicle seat. The control and evaluation circuit is configured to operate in a second mode of operation, during which it measures electrical current flowing into the seat frame connector.

Capacitive sensor

A capacitive occupant detection system has an oscillator and an electrode operatively coupled to the oscillator, to which the oscillator applies an oscillating voltage signal. In response to the oscillating voltage being applied, an electric current is caused to flow in the electrode, the current being responsive to an electric-field-influencing property of an object or occupant proximate to the electrode. The current caused to flow in the electrode has a first current component in phase with the oscillating voltage signal and a second current component 90&#xb0;-phase-offset with respect to the oscillating voltage signal. A sensing circuit is operatively coupled to the electrode and to the oscillator so as to generate a first signal indicative of the first current component and a second signal indicative of the second current component. The first signal indicative of the first current component and the second signal indicative of the second current component are provided to a processor, which is operatively coupled to the sensing circuit and which determines an occupancy state based upon the first and second signals indicative of the first and second current components, respectively, and outputs an output signal indicative of the occupancy state.

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Saarbrücken, Germany

Frank Althaus