Remotely powered and remotely interrogated wireless digital sensor telemetry system to detect corrosion

• US 8,502,675 B2
• Filed: 04/08/2010
• Issued: 08/06/2013
• Est. Priority Date: 09/23/2002
• Status: Active Grant

• Current Assignee: Hottinger Bruel & Kjaer Incorporated
• Original Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Inventors: Hamel, Michael John, Arms, Steven W., Townsend, Christopher P.
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): BEE, ANDREW W.
• Application Number:
  US12/756,978
• Publication Number:
  US 20110248825A1
• Time in Patent Office: 1,216 Days
• Field of Search: 340/572.1, 340/572.4, 340/572.5, 340/572.7, 340/10.1, 340/10.4
• US Class Current: 340/572.4
• CPC Class Codes: G06K 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08
• CPC Class Codes: H04Q 2209/886 using energy harvesting, e.g. solar, wind or mechanical
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A corrosion sensing system includes a reader, a radiation receiving device, a sensing transponder, and a member. The sensing transponder includes a communications device, a processor, and a sensor. The member is subject to corrosion. The sensor is located to detect corrosion of the member. The communications device is connected for transmitting sensor data. The transponder is powered by electricity derived from electromagnetic radiation transmitted by the reader that is received by the radiation receiving device.

Claims

1. A corrosion sensing system comprising

a reader,

a radiation receiving device,

a sensing transponder, and

a member,

wherein said sensing transponder includes

a communications device,

a processor, and

a sensor,

wherein said member is subject to corrosion,

wherein said sensor is located to detect corrosion of said member,

wherein said radiation receiving device is connected to deliver an excitation voltage to said sensor,

wherein said communications device is connected for transmitting sensor data, and

wherein data from said sensor is conditioned to provide sensor data ratiometric with magnitude of said excitation voltage provided by said radiation receiving device to said sensor,

wherein said sensing transponder is powered by electricity derived from electromagnetic radiation transmitted by said reader that is received by said radiation receiving device.

2. A corrosion sensing system as recited in claim 1, wherein said sensing transponder can transmit at least one from the group consisting of a change in said sensor data and sensor data within an acceptable limit.

3. A corrosion sensing system as recited in claim 1, wherein said sensing transponder includes a memory for data logging.

4. A corrosion sensing system as recited in claim 1, wherein said sensing transponder further includes a rechargeable energy storage device, wherein said rechargeable energy storage device is connected to be recharged with said electricity derived from said radiation receiving device.

5. A corrosion sensing system as recited in claim 4, wherein said energy storage device is connected to provide a higher power to said sensing transponder than is available from said radiation receiving device.

6. sensing system as recited in claim 1, wherein said radiation receiving device includes one from the group consisting of a coil and an antenna.

7. A corrosion sensing system as recited in claim 6, wherein said coil includes a tap.

8. A corrosion sensing system as recited in claim 1, wherein excitation voltage provided by said radiation receiving device is rectified and wherein data from said sensor is rectified and amplified to provide sensor data ratiometric with magnitude of said excitation voltage provided by said radiation receiving device to said sensor.

9. A corrosion sensing system as recited in claim 1, wherein excitation voltage provided by said radiation receiving device is digitized and wherein data from said sensor is digitized to provide sensor data ratiometric with magnitude of excitation voltage provided by said radiation receiving device to said sensor.

10. A corrosion sensing system as recited in claim 1, wherein said radiation receiving device includes a coil having multiple taps, wherein said excitation voltage is voltage at one of said taps, wherein said one tap is dynamically selected depending on loading to provide impedance matching and efficient energy transfer.

11. A corrosion sensing system as recited in claim 1, further comprising a capacitive divider, wherein said capacitive divider includes an output.

12. A corrosion sensing system as recited in claim 11, wherein said excitation voltage is voltage at said output.

13. A corrosion sensing system as recited in claim 1, wherein said sensor comprises at least one from the group consisting of a displacement sensor, a pressure sensor, a force sensor, a torque sensor, a temperature sensor, and a corrosion sensor.

14. A corrosion sensing system as recited in claim 13, wherein said displacement sensor comprises a variable reluctance transducer.

15. A corrosion sensing system as recited in claim 14, wherein said sensor includes a differential variable reluctance transducer.

16. A corrosion sensing system as recited in claim 15, wherein said sensor includes a non-contacting differential variable reluctance transducer.

17. A corrosion sensing system as recited in claim 1, further comprising a housing containing said sensing transponder.

18. A corrosion sensing system as recited in claim 17, wherein said housing is hermetically sealed.

19. A corrosion sensing system as recited in claim 18, wherein said hermetically sealed housing is formed of conductive material, wherein said radiation receiving device is within said hermetically sealed housing, wherein said radiation receiving device is for receiving electromagnetic radiation having a frequency low enough to penetrate through said conductive material, wherein said radiation receiving device is connected to provide electrical energy derived from said electromagnetic radiation.

20. A corrosion sensing system as recited in claim 19, wherein said frequency is less than 125 kHz.

21. A corrosion sensing system as recited in claim 20, wherein said frequency is less than about 44 kHz.

22. A corrosion sensing system as recited in claim 21, wherein said frequency is about 4 kHz.

23. A corrosion sensing system as recited in claim 18, wherein said housing is fabricated of a material suitable for implanting in living tissue.

24. A corrosion sensing system as recited in claim 23, further comprising an orthopedic implant, wherein said sensing transponder includes a sensor for sensing position with respect to said orthopedic implant.

25. A corrosion sensing system as recited in claim 1, wherein said processor includes an integrated clock.

26. A corrosion sensing device as recited in claim 25, wherein said integrated clock comprises an RC clock.

27. A corrosion sensing system as recited in claim 1, wherein said communications device includes a reactive component switchably connected to affect electromagnetic radiation radiated from said reader.

28. A corrosion sensing system as recited in claim 1, wherein said reader includes a radiation transmitting device, wherein said reader comprises a circuit to detect changes in loading of said radiation transmitting device, as a result of switching of said switched reactance circuit in said sensing transponder.

29. A corrosion sensing system as recited in claim 1, wherein said sensing transponder includes a non-volatile memory connected for storing sensor data.

30. A corrosion sensing system as recited in claim 1, further comprising a plurality of said remotely powered and remotely interrogated sensing transponders, wherein each said sensing transponder has an address and wherein each said sensing transponder has a system to transmit data so as to avoid collisions.

31. A corrosion sensing system as recited in claim 30, wherein said system to avoid collisions includes a random timing generator.

32. A corrosion sensing system as recited in claim 30, wherein each of said plurality of sensing transponders includes a memory for data logging.

33. A corrosion sensing system as recited in claim 30, wherein each of said plurality of sensing transponders includes an energy storage device.

34. A corrosion sensing system as recited in claim 1, wherein said member includes reinforcement bar embedded in concrete.

35. A corrosion sensing system as recited in claim 1, wherein said member includes a test structure including a plurality of plates.

36. A corrosion sensing system as recited in claim 26, wherein said RC clock is connected to encode RC clock data with data derived from said sensor.

37. A corrosion sensing system as recited in claim 25, wherein said integrated clock is connected to encode integrated clock data with data derived from said sensor.