Stress wave sensor

• US 20050275047A1
• Filed: 06/11/2004
• Published: 12/15/2005
• Est. Priority Date: 06/11/2004
• Status: Active Grant

• Current Assignee: Robert Bosch Corporation (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Stuetzler, Frank-Juergen
• Granted Patent: US 7,188,511 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: G01H 11/06 by electric means
• CPC Class Codes: G01H 17/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00

Abstract

Method and device for sensing stress waves. One embodiment is a method that includes providing a bendable support with one or more mounts each located at an end of the support; attaching a semiconductor element containing a plurality of piezoresistors, each having impedance, to the support; connecting the support to the component by the mounts of the support; and sensing the impedance of the plurality of piezoresistors.

Claims

1. A stress wave sensor comprising:

a support containing one or more mounts;

a semiconductor element mounted to the support between the mounts and containing a plurality of piezoresistors each piezoresistor having an impedance and input and output terminals; and

a circuit configured to be coupled to the input and output terminals of the plurality of piezoresistors and capable of sensing the impedance of the plurality of piezoresistors.

2. The stress wave sensor of claim 1, wherein the plurality of piezoresistors includes sensing piezoresistors and reference piezoresistors.

3. The stress wave sensor of claim 2, wherein the impedance of the sensing piezoresistors is different than the impedance of the reference piezoresistors.

4. The stress wave sensor of claim 1, wherein the support is configured to receive stress waves.

5. The stress wave sensor of claim 1, wherein the semiconductor element is configured to be mounted along an entire surface of the support such that stress waves that travel through the support distort the semiconductor element.

6. The stress wave sensor of claim 1, wherein the mounts of the support are located at the ends of the support.

7. The stress wave sensor of claim 1, wherein the mounts of the support are configured to be attached to a component requiring stress wave sensing.

8. The stress wave sensor of claim 5, wherein the mounts of the support are configured to allow stress waves traveling through the component to also travel through the support.

9. The stress wave sensor of claim 1, wherein the circuit is configured to be mounted on a printed circuit board.

10. The stress wave sensor of claim 1, further comprising a connector configured to be coupled to the circuit and a plurality of control units.

11. A method of sensing stress waves within a component, the method comprising:

providing a bendable support with one or more mounts;

attaching a semiconductor element containing a plurality of piezoresistors, each having impedance, to the support;

connecting the support to the component with the mounts of the support; and

sensing the impedance of the plurality of piezoresistors.

12. The method as claimed in claim 11, wherein attaching the semiconductor element comprises mounting the semiconductor element along an entire surface of the support such that stress waves traveling through the support distort the semiconductor element.

13. The method as claimed in claim 11, further comprising transmitting data from the piezoresistors to a control unit.

14. The method as claimed in claim 11, further comprising providing a plurality of piezoresistors including sensing piezoresistors and reference piezoresistors.

15. The method as claimed in claim 14, further comprising providing the reference piezoresistors with a different impedance than the reference piezoresistors.

16. The method as claimed in claim 11, wherein the mounts of the support are located at the ends of the support.

17. A system of sensing stress waves in a component, the system comprising:

a support with one or more mounts and configured to be attached to the component;

a plurality of piezoresistors each with an impedance and input and output terminals;

a semiconductor element containing the plurality of piezoresistors and configured to be attached to the support between the mounts of the support; and

a circuit capable of being coupled to input and output terminals of the plurality of piezoresistors and capable of sensing the impedance of the plurality of piezoresistors.

18. The system as claimed in claim 17, wherein the plurality of piezoresistors comprises reference piezoresistors and sensing piezoresistors.

19. The system as claimed in claim 17, wherein the support is configured to receive stress waves traveling through the component.

20. The system as claimed in claim 17, wherein the impedance of the reference piezoresistors is different than the impedance of the sensing piezoresistors.

21. The system as claimed in claim 17, wherein the semiconductor element is configured to be mounted along an entire surface of the support such that stress waves that travel through the support distort the semiconductor element.

22. The system as claimed in claim 17, wherein the circuit is configured to be mounted to a printed circuit board.

23. The system as claimed in claim 17, further comprising a connector configured to be directly coupled to the semiconductor element to transmit data to and from the semiconductor element without processing the data.

24. The system as claimed in claim 17, wherein the one or more mounts of the support are located at the ends of the support.

25. A sensor for sensing stress waves in a component, the sensor comprising:

a flexible support having a first end and a second end, a longitudinal axis, a first support located proximate the first end, and a second support located proximate the second end;

a semiconductor element containing a plurality of piezoresistors and mounted to the flexible support between the first and second supports;

the plurality of piezoresistors including a first pair of piezoresistors and a second pair of piezoresistors, each of the first pair of piezoresistors having a length that is greater than a length of each of the second pair of piezoresistors;

the first pair of piezoresistors located along and substantially parallel to the longitudinal axis of the flexible support; and

a connector coupled to the semiconductor element so as to be able to receive a first signal derived from a second signal delivered to at least one of the plurality of piezoresistors.

26. A system of sensing stress waves in a component, the system comprising:

a plurality of piezoresistors each with an impedance and input and output terminals;

a semiconductor support containing the plurality of the piezoresistors and one or more mounts and configured to be attached to the component;

a circuit capable of being coupled to input and output terminals of the plurality of piezoresistors and capable of sensing the impedance of the plurality of piezoresistors.

27. The system as claimed in claim 26, wherein the plurality of piezoresistors comprises reference piezoresistors and sensing piezoresistors.

28. The system as claimed in claim 26, wherein the semiconductor support is configured to receive stress waves traveling through the component.

29. The system as claimed in claim 26, wherein the impedance of the reference piezoresistors is different than the impedance of the sensing piezoresistors.

30. The system as claimed in claim 26, wherein the circuit is configured to be mounted to a printed circuit board.

31. The system as claimed in claim 26, further comprising a connector configured to be directly coupled to the semiconductor element to transmit data to and from the semiconductor element without processing the data.

32. The system as claimed in claim 26, wherein the one or more mounts of the support are located at the ends of the support.