Methods for controlling a capacitive anti-trap system and anti-trap system

Patent metadata

Field	Value
Publication number	US-10669765-B2
Application number	US-201314418890-A
Country	US
Kind code	B2
Filing date	Aug 1, 2013
Priority date	Aug 2, 2012
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

The present invention relates to methods for controlling a capacitive anti-trap system of a vehicle. At least two transmission electrodes and one reception electrode of the capacitive anti-trap system are used for detecting an obstacle, and an electrical field is generated by a pair comprising transmission electrode and reception electrode by actuation of the respective transmission electrode by alternating electric current, said electrical field being influenced by an obstacle such that an electrical capacitance is measurably changed. A changing electrical capacitance is determinable on the basis of a signal received via the reception electrode and this signal is evaluated by means of an electronic evaluation unit at least during closing of the vehicle closing element in order to determine the presence of an obstacle in the displacement path of the vehicle closing element.

First claim

The invention claimed is:

1. A method for controlling a capacitive anti-trap system of a vehicle to detect an obstacle in a displacement path of a vehicle closing element and to prevent the obstacle from being trapped between the closing vehicle closing element and a vehicle structure defining a vehicle body opening which is closed by the vehicle closing element in a closed position, the method comprising:
actuating at least two transmission electrodes simultaneously by an alternating current via a frequency multiplexer to generate an electrical field in the displacement path which can be influenced by the obstacle being in at least one of at least two different monitoring regions, the electrical field being between each respective one of the at least two transmission electrodes and a reception electrode during closing of the vehicle closing element, wherein an electrical capacitance of the electrical field is configured to be measurably changed due to an obstacle being in at least one of the at least two monitoring regions;
receiving a single signal via the reception electrode, the simultaneous actuation of the at least two transmission electrodes resulting in the single signal being indicative of an obstacle in one of the at least two monitoring regions; and
evaluating the single signal using an electronic evaluation unit to determine whether an obstacle is present in one of the at least two monitoring regions,
wherein the at least two transmission electrodes are actuated simultaneously by alternating electric current such that it is possible to assess in which of the at least two monitoring regions an obstacle is present via the electronic evaluation unit on the basis of the single signal,
wherein the at least two transmission electrodes are actuated in phase opposition, and
wherein the at least two transmission electrodes are configured such that, owing to the actuation in phase opposition, a measurable voltage signal is almost zero when there is no obstacle present and the mathematical sign of the received voltage signal indicates the monitoring region in which an obstacle is present.

2. The method as claimed in claim 1 , wherein one of the at least two transmission electrodes is actuated by alternating current having a sinusoidal waveform, and another of the at least two other transmission electrodes is actuated simultaneously by alternating current having a cosinusoidal waveform.

3. The method as claimed in claim 1 , wherein the electronic evaluation unit comprises a demodulator configured to demodulate a received carrier signal and configured to evaluate in which of the monitoring regions an obstacle is present on the basis of the demodulated signal.

4. The method as claimed in claim 1 , wherein the at least two transmission electrodes are spaced physically apart from one another so that, with the at least one reception electrode, they are configured to generate an electrical field which can be influenced by an obstacle in two different monitoring regions, and wherein the two transmission electrodes are configured to be operated in at least two different operating modes, wherein, in a first operating mode, it is possible to evaluate whether an obstacle is present in one of the monitoring regions and, in a second operating mode, it is additionally possible to evaluate in which of the monitoring regions an obstacle is present.

5. The method as claimed in claim 4 , wherein, in the first operating mode, the two transmission electrodes are actuated simultaneously by alternating electric current via a single signal generator and, in the second operating mode, the two transmission electrodes are actuated separately from one another by alternating electric current.

6. The method as claimed in claim 5 , wherein, in the second operating mode, the two transmission electrodes are actuated by alternating electric current via the single signal generator with a temporal offset with respect to one another.

7. The method as claimed in claim 4 , wherein, in the first operating mode, the two transmission electrodes are actuated in phase and, in a second operating mode, said transmission electrodes are actuated in phase opposition.

8. The method as claimed in claim 4 , wherein changeover between the first and second operating modes can be effected via at least one electronic switch.

9. The method as claimed in claim 8 , wherein the electronic switch is triggered by a switching signal which is configured to be generated by an obstacle detection device of the vehicle on identification of a potential obstacle in the region of the vehicle body opening.

10. A method for controlling a capacitive anti-trap system of a vehicle to detect an obstacle in a displacement path of a vehicle closing element and to prevent the obstacle from being trapped between the closing vehicle closing element and a vehicle structure defining a vehicle body opening which is closed by the vehicle closing element in a closed position, the method comprising:
actuating at least two transmission electrodes simultaneously by an alternating current via quadrature amplitude modulation to generate an electrical field in the displacement path which can be influenced by the obstacle being in at least one of at least two different monitoring regions, the electrical field being between each respective one of the at least two transmission electrodes and a reception electrode during closing of the vehicle closing element, wherein an electrical capacitance of the electrical field is configured to be measurably changed due to an obstacle being in at least one of the at least two monitoring regions;
receiving a single signal via the reception electrode, the simultaneous actuation of the at least two transmission electrodes resulting in the single signal being indicative of an obstacle in one of the at least two monitoring regions; and
evaluating the single signal using an electronic evaluation unit to determine whether an obstacle is present in one of the at least two monitoring regions,
wherein the at least two transmission electrodes are actuated simultaneously by alternating electric current such that it is possible to assess in which of the at least two monitoring regions an obstacle is present via the electronic evaluation unit on the basis of the single signal,
wherein the at least two transmission electrodes are actuated in phase opposition, and
wherein the at least two transmission electrodes are configured such that, owing to the actuation in phase opposition, a measurable voltage signal is almost zero when there is no obstacle present and the mathematical sign of the received voltage signal indicates the monitoring region in which an obstacle is present.

11. The method as claimed in claim 10 , wherein one of the at least two transmission electrodes is actuated by alternating current having a sinusoidal waveform, and another of the at least two other transmission electrodes is actuated simultaneously by alternating current having a cosinusoidal waveform.

12. A capacitive anti-trap system for a vehicle, wherein the anti-trap system comprises: at least two transmission electrodes and at least one reception electrode, wherein an electrical field is configured to be generated by a pair comprising one of the at least two transmission electrodes and one of the at least one reception electrodes by actuation of the transmission electrode by alternating electric current, said electrical field being configured to be influenced by an obstacle such that an electrical capacitance is measurably changed; and
an electronic evaluation unit, via which a signal received via a reception electrode can be evaluated to ascertain whether an electrical capac

Assignees

• Brose Fahrzeugteile

Inventors

• Herrmann Christian
• Pohl Florian
• Wuerstlein Holger

Classifications

• H03K2217/960775

  Emitter-receiver or "fringe" type detection, i.e. one or more field emitting electrodes and corresponding one or more receiving electrodes · CPC title

• H03K17/955 Primary

  using a capacitive detector · CPC title

• E05F15/46 Primary

  responsive to changes in electrical capacitance · CPC title

• H03K2217/96078

  Sensor being a wire or a strip, e.g. used in automobile door handles or bumpers · CPC title