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 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 ZSO on an object-to-ground impedance ZOG measurement 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 ZSO on 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 ZOG completely 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.

Abstract: 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 ZSO on an object-to-ground impedance ZOG measurement 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 ZSO on 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 ZOG completely 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.

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 capacitive sensor member of a vehicle seat occupant detection and classification device that includes a first electrically conductive antenna member and at least a second electrically conductive antenna member that is adjacently arranged to the first electrically conductive antenna member without any mutual galvanic connection. At least one electrically conductive bridging member is fixedly attached to at least one elastic spacer member that has elastic mechanical properties in a specified direction. If a mechanical load is applied to the capacitive sensor member in the specified direction that is equal to or larger than a predetermined value for the mechanical load, the at least one electrically conductive bridging member provides at least one galvanic contact between the first electrically conductive antenna member and the second electrically conductive antenna member.

Abstract: A capacitive sensor member (130) of a vehicle seat occupant detection and classification device (18) comprises a first electrically conductive antenna member (132) and at least a second electrically conductive antenna member (134) that is adjacently arranged to the first electrically conductive antenna member (132) without any mutual galvanic connection. At least one electrically conductive bridging member (146) is fixedly attached to at least one elastic spacer member (148) that has elastic mechanical properties in a specified direction (54). If a mechanical load (F) is applied to the capacitive sensor member (130) in the specified direction (54) that is equal to or larger than a predetermined value for the mechanical load (F), the at least one electrically conductive bridging member (146) provides at least one galvanic contact between the first electrically conductive antenna member (132) and the second electrically conductive antenna member (134).

Abstract: In addition to the loading mode of a capacitive sensing device of a seat occupancy detection and classification system, a second measurement mode is introduced, which allows a discrimination of objects (CRS or human) with and without grounding condition. Depending on the value of the new measurement, the data is allocated to different groups which are subject to different thresholds in the loading mode. This means that if the new measurement indicates a grounding condition of the object, a higher threshold in the loading mode will be applied. In this way CRS with grounding condition will be classified by means of the higher threshold, resulting in a robustness increase. Typical human sitting positions do not show a grounding condition and will be classified by the lower threshold.

Abstract: A capacitive sensor member of a seat occupant classification device for use in seats, in particular in vehicle seats. The capacitive sensor member includes at least one electrically conductive sense electrode that has an optimized shape for use in vehicle seats equipped with child restraint system anchorages. A capacitive seat occupant classification system is provided that includes the capacitive sensor member.

Abstract: A sensor arrangement for detecting a safe installation state of an automated installation has an input circuit designed to receive a first input signal and at least one further input signal. The first input signal depends on the safe installation state to be detected. The further input signal depends on a further operational state. The sensor arrangement also has a first output and at least one second output and an evaluation unit for outputting a first output signal and a second output signal at the first and second outputs, respectively. The evaluation unit is designed to evaluate the first input signal in a failsafe manner and on the basis thereof produce a redundant signal pair at the first and second outputs to signal a safe installation state, and to evaluate the further input signal and on the basis thereof generate non-redundant output signals different from the redundant signal pair.

Abstract: A sensor arrangement for detecting a safe installation state of an automated installation has an input circuit designed to receive a first input signal and at least one further input signal. The first input signal depends on the safe installation state to be detected. The further input signal depends on a further operational state. The sensor arrangement also has a first output and at least one second output and an evaluation unit for outputting a first output signal and a second output signal at the first and second outputs, respectively. The evaluation unit is designed to evaluate the first input signal in a failsafe manner and on the basis thereof produce a redundant signal pair at the first and second outputs to signal a safe installation state, and to evaluate the further input signal and on the basis thereof generate non-redundant output signals different from the redundant signal pair.