Capacitive sensor

• US 10,666,252 B2
• Filed: 07/13/2015
• Issued: 05/26/2020
• Est. Priority Date: 09/16/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schupp, Dietrich, Frangen, Joachim, Eisenhardt, Volker, Wenzel, Norbert, Hartmann, Volker, Gaesslein, Frank
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): Curtis, Sean
• Application Number:
  US15/509,022
• Publication Number:
  US 20170257094A1
• Time in Patent Office: 1,779 Days
• Field of Search: 324658, 324686
• CPC Class Codes: F16P 3/148 using capacitive technology
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/088 operating with electric fields G01V3/082 takes precedence
• CPC Class Codes: H03K 17/955 using a capacitive detector

Abstract

A capacitive sensor for detecting at a surface that an object is approaching which is designed to be flexurally rigid and/or torsionally rigid. The capacitive sensor includes a circuit carrier and/or a spacer element and/or a carrier. In this case, the circuit carrier is designed to be flexurally rigid and/or torsionally rigid and/or the spacer element is designed to be flexurally rigid and/or torsionally rigid and/or the carrier is designed to be flexurally rigid and/or torsionally rigid. The circuit carrier is in the form of a circuit board and is used for making electrical contact with the electrically conductive surfaces of the capacitive sensor. The spacer element is situated between the electrically conductive surfaces and the circuit carrier. The carrier is designed for connecting the capacitive sensor to a machine part, in particular to a machine part of an industrial robot.

Claims

1. A capacitive sensor for detecting at a surface that an object is approaching, the capacitive sensor being designed to be at least one of flexurally rigid and torsionally rigid, the capacitive sensor comprising:

a circuit carrier having a planar surface;

at least two electrically conductive surfaces which are laterally spaced apart and adjoin one another, the electrically conductive surfaces being co-planar with each other and laterally spaced apart from each other and disposed on the planar surface of the circuit carrier, wherein the conductive surfaces are insulated with respect to one another and form an electrical capacitor in such a way that an electric field corresponding to a capacitance of the electrical capacitor is formed across the co-planar conductive surfaces and that a value of the capacitance changes when an object is approaching;

a further circuit carrier having a further planar surface, the further circuit carrier being disposed with respect to the circuit carrier at an angle between 45° and

90°

with respect to one another; and

at least two further electrically conductive surfaces which are laterally spaced apart and adjoin one another, the further electrically conductive surfaces being laterally spaced apart from each other and disposed on the further planar surface of the circuit carrier of the further circuit carrier so that the electrically conductive surfaces and the further electrically conductive surfaces are at an angle between 45° and

90°

with respect to one another.

2. The capacitive sensor as recited in claim 1, wherein the circuit carrier is at least one of flexurally rigid and torsionally rigid.

3. The capacitive sensor as recited in claim 2, wherein the circuit carrier is a circuit board including strip conductors, the circuit carrier contacting the electrically conductive surfaces with electrical components.

4. The capacitive sensor as recited in claim 3, wherein the capacitive sensor includes a spacer element, the spacer element being designed to be at least one of flexurally rigid and torsionally rigid.

5. The capacitive sensor as recited in claim 4, wherein the spacer element is situated between the electrically conductive surfaces and the circuit carrier.

7. The capacitive sensor as recited in claim 1, wherein the capacitive sensor includes a carrier, the carrier being at least one of flexurally rigid and torsionally rigid.

8. The capacitive sensor as recited in claim 7, wherein the carrier is designed in such a way that the capacitive sensor is connectable to a machine part via the carrier.

9. The capacitive sensor as recited in claim 2, wherein the capacitive sensor includes one further circuit carrier, the further circuit carrier being a circuit board or foil, and the electrically conductive surfaces are situated on the further circuit carrier.

10. The capacitive sensor as recited in claim 2, wherein the capacitive sensor is at least one of flexurally rigid and torsionally rigid only after at least one of:

i) encapsulating the capacitive sensor, ii) filling the capacitive sensor with foam, and iii) embedding the capacitive sensor in a gel.

12. The capacitive sensor as recited in claim 1, wherein at least two of the electrically conductive surfaces are slanted with respect to one another at an angle between 0°

and 135°

.

13. The capacitive sensor as recited in claim 12, wherein the angle is between 45°

and 90°

.

14. The capacitive sensor as recited in claim 1, wherein the capacitive sensor includes at least three electrically conductive surfaces which are interconnected in such a way that the electrically conductive surfaces form at least two electrical capacitors, the electrically conductive surfaces being situated in such a way that detection areas, which are formed by electrical field lines, of the two electrical capacitors at least partially overlap.

15. The capacitive sensor as recited in claim 14, wherein the at least three electrically conductive surfaces include four electrically conductive surfaces.

6. A capacitive sensor for detecting at a surface that an object is approaching, the capacitive sensor being designed to be at least one of flexurally rigid and torsionally rigid, the capacitive sensor comprising:

a circuit carrier having a planar surface;

at least two electrically conductive surfaces which are laterally spaced apart and adjoin one another, the electrically conductive surfaces being co-planar with each other and laterally spaced apart from each other and disposed on the planar surface of the circuit carrier, wherein the conductive surfaces are insulated with respect to one another and form an electrical capacitor in such a way that an electric field corresponding to a capacitance of the electrical capacitor is formed across the co-planar conductive surfaces and that a value of the capacitance changes when an object is approaching, wherein;

the circuit carrier is at least one of flexurally rigid and torsionally rigid,

the circuit carrier is a circuit board including strip conductors, the circuit carrier contacting the electrically conductive surfaces with electrical components,

the capacitive sensor includes a spacer element, the spacer element being designed to be at least one of flexurally rigid and torsionally rigid,

the spacer element is situated between the electrically conductive surfaces and the circuit carrier

the electrically conductive surfaces make contact with the circuit carrier via electrically conductive connections through the spacer element.

11. A capacitive sensor for detecting at a surface that an object is approaching, the capacitive sensor being designed to be at least one of flexurally rigid and torsionally rigid, the capacitive sensor comprising:

a circuit carrier having a planar surface;

at least two electrically conductive surfaces which are laterally spaced apart and adjoin one another, the electrically conductive surfaces being co-planar with each other and laterally spaced apart from each other and disposed on the planar surface of the circuit carrier, wherein the conductive surfaces are insulated with respect to one another and form an electrical capacitor in such a way that an electric field corresponding to a capacitance of the electrical capacitor is formed across the co-planar conductive surfaces and that a value of the capacitance changes when an object is approaching, wherein the capacitive sensor is made up of a composite of at least two different layers, each layer being itself flexible and the capacitive sensor is at least one of flexurally rigid and torsionally rigid only due to the composite of the two different layers, at least one of the two different layers including at least one of a circuit carrier, a spacer element, a carrier, and a further circuit carrier.

16. A machine part including multiple capacitive sensors, the capacitive sensors being at least one of flexurally rigid and torsionally rigid, the capacitive sensors including at least two electrically conductive surfaces which are laterally spaced apart and adjoin one another, the conductive surfaces being insulated with respect to one another and form an electrical capacitor in such a way that a value of a capacitance of the electrical capacitor changes when an object is approaching, wherein the capacitive sensors cover the entire outer surface of the machine part in such a way that spatial surroundings of the machine part are monitored for the approach by an object, each of the capacitive sensor comprising:

a circuit carrier having a planar surface, wherein the electrically conductive surfaces are co-planar with each other and laterally spaced apart from each other and disposed on the planar surface of the circuit carrier, wherein the conductive surfaces are insulated with respect to one another and form the electrical capacitor in such a way that an electric field corresponding to the capacitance of the electrical capacitor is formed across the co-planar conductive surfaces and that a value of the capacitance changes when the object is approaching, wherein at least one of the capacitive sensors further includes;

a further circuit carrier having a further planar surface, the further circuit carrier being disposed with respect to the circuit carrier of the at least one capacitive sensor at an angle between 45° and

90°

with respect to one another; and

at least two further electrically conductive surfaces which are laterally spaced apart and adjoin one another, the further electrically conductive surfaces being laterally spaced apart from each other and disposed on the further planar surface of the further circuit carrier so that the electrically conductive surfaces and the further electrically conductive surfaces are at an angle between 45° and

90°

with respect to one another.

17. The machine part as recite in claim 16, wherein the machine part is an industrial robot.