Anti-pinch sensor

• US 8,228,077 B2
• Filed: 11/28/2008
• Issued: 07/24/2012
• Est. Priority Date: 11/30/2007
• Status: Expired due to Fees

• Current Assignee: Brose Fahrzeugteile GmbH & Company KG Hallstadt (Brose), Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Hallstadt
• Original Assignee: Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Hallstadt
• Inventors: Wuerstlein, Holger, Weingaertner, Thomas
• Primary Examiner(s): Dole, Timothy J
• Application Number:
  US12/325,133
• Publication Number:
  US 20090146827A1
• Time in Patent Office: 1,334 Days
• Field of Search: 324/658, 324/661, 324/663, 324/686, 324/688, 340/545.04, 340/561, 340/562
• US Class Current: 324/686
• CPC Class Codes: E05F 15/46 responsive to changes in electrical capacitance
• CPC Class Codes: E05Y 2800/342 Deformable
• CPC Class Codes: E05Y 2900/531 Doors
• CPC Class Codes: E05Y 2900/55 Windows
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 2217/96015 Constructional details for touch switches for capacitive touch switches see H03K2217/9607
• CPC Class Codes: H03K 2217/96075 involving bridge circuit
• CPC Class Codes: H03K 2217/960775 Emitter-receiver or "fringe" type detection, i.e. one or more field emitting electrodes and corresponding one or more receiving electrodes

Abstract

An Anti-pinch sensor, in particular for detecting an obstacle in the path of an actuator of a motor vehicle is provided. The anti-pinch sensor includes a first measurement electrode and a second electrically isolated measurement electrode spaced a distance from the first measurement electrode, wherein the first measurement electrode is designed to generate an external electric field with respect to the second measurement electrode, and wherein the first and second measurement electrodes are elastically supported relative to an electrically isolated ground electrode. In addition, a sensor device having such an anti-pinch sensor is disclosed. The anti-pinch sensor is suitable as both a contactless and a tactile sensor. Detection of surface deposits of contaminants or water is easily possible.

Claims

1. An anti-pinch sensor for detecting an obstacle in the path of an actuator of a motor vehicle, the anti-pinch sensor comprising:

a first measurement electrode;

a second electrically isolated measurement electrode spaced a distance from the first measurement electrode;

a flexible sensor body elastically supporting the first and second measurement electrodes relative to an electrically isolated ground electrode; and

a measurement electronics unit for detecting a measured capacitance between the first and the second measurement electrodes for contactless detection of the obstacle, and for detecting compression of the sensor body with respect to the ground electrode based on a corresponding change in the measured capacitance as the ground electrode is drawn closer to the first and second measurement electrodes for tactile detection of the obstacle,

wherein the first measurement electrode is configured to generate an external electric field with respect to the second measurement electrode.

2. Anti-pinch sensor according to claim 1, wherein the first and second measurement electrodes are arranged on a first plane that is spaced apart from a second plane on which the ground electrode is arranged.

3. Anti-pinch sensor according to claim 1, further comprising an intermediate layer formed of an elastic and electrically insulating material for elastically supporting the two measurement electrodes with respect to the ground electrode.

4. Anti-pinch sensor according to claim 3, wherein the electrodes and the intermediate layer are arranged in a sensor body made of a flexible substrate material.

5. Anti-pinch sensor according to claim 4, wherein the sensor body extends essentially along a longitudinal direction, and wherein the first measurement electrode is subdivided in the longitudinal direction into separately controllable individual electrodes.

6. Anti-pinch sensor according to claim 5, wherein all measurement electrodes are subdivided in the longitudinal direction into separately controllable individual electrodes.

7. Anti-pinch sensor according to claim 5, wherein supply lines to the individual electrodes are shielded by the ground electrode.

8. Anti-pinch sensor according to claim 7, wherein a second ground electrode is provided as a sensor component, and wherein the supply lines are arranged for shielding between the two ground electrodes.

9. Anti-pinch sensor according to claim 1, wherein the ground electrode is a component of the sensor.

10. Anti-pinch sensor according to claim 1, wherein the measurement electrodes are each located in an edge region.

11. Anti-pinch sensor according to claim 1, wherein the electrodes are each flat in design.

12. Anti-pinch sensor according to claim 11, wherein the area of the ground electrode sweeps the areas of both measurement electrodes in projection.

13. Anti-pinch sensor according to claim 1, wherein a third measurement electrode, electrically isolated from the first and second measurement electrodes, is provided that is adjacent to the second measurement electrode, and in that the measurement electrodes are designed to produce a first external electric field between the first and second measurement electrodes and a second external electric field between the first and third measurement electrodes, wherein the second external electric field has a smaller range than the first external electric field.

14. Anti-pinch sensor according to claim 1, wherein the measurement electronics unit is designed to identify as a pinch event a measured capacitance that is decreasing with respect to a ground capacitance.

15. Anti-pinch sensor according to claim 1, wherein the measurement electronics unit is designed to identify as contamination a measured capacitance that is increasing with respect to a ground capacitance.

16. Anti-pinch sensor according to claim 1, wherein a third measurement electrode, electrically isolated from the first and second measurement electrodes, is provided that is adjacent to the second measurement electrode, in that the measurement electrodes are designed to produce a first external electric field between the first and second measurement electrodes and a second external electric field between the first and third measurement electrodes, wherein the second external electric field has a smaller range than the first external electric field, and in that the measurement electronics unit is designed to detect a drift in the capacitance between the first and second measurement electrodes as compared to a capacitance between the first and third measurement electrodes.

17. Anti-pinch sensor according to claim 1, wherein the electrodes and an intermediate layer, the intermediate layer being formed of an elastic and electrically insulating material for elastically supporting the two measurement electrodes with respect to the ground electrode, are arranged in a sensor body made of a flexible substrate material, in that the sensor body extends essentially along a longitudinal direction, in that the first measurement electrode is subdivided in the longitudinal direction into separately controllable individual electrodes, and in that the measurement electronics unit is designed to control the individual electrodes separately.

18. Anti-pinch sensor according to claim 17, wherein all measurement electrodes are subdivided in the longitudinal direction into individual electrodes.

19. Anti-pinch sensor according to claim 1, wherein the first and second measurement electrodes are not directly interposed by any ground electrodes.