Industrial process device utilizing magnetic induction

• US 7,913,566 B2
• Filed: 05/23/2006
• Issued: 03/29/2011
• Est. Priority Date: 05/23/2006
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C.
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US11/439,095
• Publication Number:
  US 20070273496A1
• Time in Patent Office: 1,771 Days
• Field of Search: 736/49, 735/79, 736/59, 736/60, 738/613.55, 738/613.56, 738/613.57, 738/612.2, 738/612.3, 738/611.2, 702104-105, 702/45, 702/55, 702/69
• US Class Current: 73/649
• CPC Class Codes: G01H 1/08 Amplitude

Abstract

A process device for coupling to an industrial process for use in monitoring or controlling the process includes a device housing configured to physically couple to the industrial process. A coil of wire is mounted to the housing and a magnet is configured to move through the coil of wire. The relative movement of the magnet is responsive to vibrations in the industrial process. Such relative movement induces an electrical current in the coil of wire. Electrical circuitry in the housing includes an input to receive the electrical current from the coil of wire.

Claims

1. A process device for coupling to an industrial process for use in monitoring or controlling the process, comprising:

a device housing configured to physically couple to the industrial process;

a plurality of accelerometers, including;

a coil of wire mounted to the housing;

a magnet configured to move through the coil of wire along a path in response to vibrations in the industrial process thereby inducing an electrical current in the coil of wire;

first and second springs arranged at opposed ends of the path configured to receive the magnet in a first direction and responsively urge the magnet in a second, opposed direction, the springs thereby configured to reverse a direction of movement of the magnet relative to the coil, the path having a path length and the magnet having a magnet length which is less than the path length whereby the magnet touches at most one of the first and second springs at any time;

electrical circuitry in the housing having an input to receive the electrical current from the coil of wire, the electrical circuitry responsive to the electrical current from the vibrations; and

a microcontroller coupled to the plurality of accelerometers configured to monitor outputs from the plurality of accelerometers over a period of time and identify an orientation of the magnet and coil of wire based upon a selected criteria, the microprocessor further configured to instruct an operator to orient the magnet and coil of wire through a local operator interface based upon the identified orientation.

2. The process device of claim 1 wherein the electrical circuitry is configured to diagnose operation of the industrial process based upon the electrical current.

3. The process device of claim 2 including an analog to digital converter having a digital output related to digitize the electrical current.

4. The process device of claim 2 wherein the microcontroller is further configured to perform diagnostics.

5. The process device of claim 2 wherein the microcontroller is configured to diagnose operation of the industrial process are based upon an amplitude of vibrations in the industrial process.

6. The process device of claim 2 wherein the microcontroller is configured to diagnose operation of the industrial process are based upon a frequency of vibrations in the industrial process.

7. The process device of claim 2 wherein the microcontroller is configured to diagnose operation of the industrial process are based upon a signature in the vibrations in the industrial process.

8. The process device of claim 2 wherein the microcontroller provides a diagnostic output based upon the vibrations and data stored in a memory.

9. The process device of claim 1 including a process interface configured to sense a process variable.

10. The process device of claim 1 wherein the process device includes a process interface configured to control the process.

11. The process device of claim 1 wherein the electrical circuitry includes power storage circuitry configured to store power from the electrical current from the coil of wire.

12. The process device of claim 11 wherein the power storage circuitry comprises a capacitor.

13. The process device of claim 11 including a rectifier to rectify the electrical current from the coil of wire.

14. The process device of claim 1 including a sensor configured to sense vibrations.

15. The process device of claim 14 wherein the orientation of the magnet is adjusted based upon the sensed vibrations.

16. The process device of claim 14 wherein the sensor comprises a three axis accelerometer.

17. The process device of claim 12 wherein the capacitor comprises a supercapacitor.

27. The process device of claim 1 wherein the electrical current generated from the vibrations is configured to completely power the process device.

28. The process device of claim 1 including wireless communication circuitry.

29. The process device of claim 28 wherein the wireless communication circuitry is powered with the electrical current generated from the vibrations.

18. A method for sensing vibrations in a process device coupled to an industrial process of the type used in monitoring or controlling the industrial process, the method comprising:

physically coupling a housing of the process device to the industrial process;

receiving vibrations from the industrial process through the physical coupling;

moving a magnet through a coil of wire along a path in response to the vibrations and generating an electrical current in the coil of wire;

providing first and second opposed springs on opposed ends of the path arranged to receive the magnet in a first direction and urge movement of the magnet in a second opposed direction thereby reversing a direction of movement of the magnet relative to the coil, the path having a path length and the magnet having a magnet length which is less than the path length whereby the magnet touches at most one of the first and second springs at any time;

providing the electrical current to circuitry of the process device, and responding with the circuitry to the electrical current;

measuring vibrations with a vibration sensor;

receiving measured vibrations from the vibration sensor and the coil of wire and responsively identifying a preferred orientation of the magnet and coil of wire based upon a selected criteria; and

providing an output to an operator to orient the magnet and the coil of wire based upon the identified preferred orientation.

19. The method of claim 18 including diagnosing operation of the industrial process based upon the electrical current.

20. The method of claim 19 wherein the diagnosing is based upon an amplitude of vibrations.

21. The method of claim 19 wherein the diagnosing is based upon a frequency of vibrations.

22. The method of claim 19 wherein the diagnosing is based upon a signature in the vibrations.

23. The method of claim 19 wherein the diagnosing is based upon the vibrations and stored data.

24. The method of claim 18 including storing power storage based from the electrical current from the coil of wire.

25. The method of claim 18 including rectifying the electrical current from the coil of wire.

26. The method of claim 19 wherein sensing vibrations includes monitoring an output of a tri-axis accelerometer.

30. The method of claim 18 including completely powering the process device with the electrical current generated from the received vibrations.

31. The method of claim 18 including communicating wirelessly with wireless communication circuitry.

32. The method of claim 31 wherein the wireless communication circuitry is powered with the electrical current generated from the received vibrations.