Diagnostics in industrial process control system

• US 20070010900A1
• Filed: 04/04/2006
• Published: 01/11/2007
• Est. Priority Date: 04/04/2005
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Eryurek, Evren, Kavaklioglu, Kadir, Lattimer, Donald, Wehrs, David
• Granted Patent: US 7,680,549 B2
• Time in Patent Office: Days
• US Class Current: 700/26
• CPC Class Codes: C10G 11/187 Controlling or regulating
• CPC Class Codes: G05B 23/0221 Preprocessing measurements, e.g. data collection rate adjustment; Standardization of measurements; Time series or signal analysis, e.g. frequency analysis or wavelets; Trustworthiness of measurements; Indexes therefor; Measurements using easily measured parameters to estimate parameters difficult to measure; Virtual sensor creation; De-noising; Sensor fusion; Unconventional preprocessing inherently present in specific fault detection methods like PCA-based methods
• CPC Class Codes: G05B 23/024 Quantitative history assessment, e.g. mathematical relationships between available data; Functions therefor; Principal component analysis [PCA]; Partial least square [PLS]; Statistical classifiers, e.g. Bayesian networks, linear regression or correlation analysis; Neural networks

Abstract

A device for diagnosing operation of an industrial process control or monitoring system includes an input configured to receive an input related to a process signal. A first statistical parameter module provides a first statistical parameter output related to a statistical parameter of the process signal. A filter provides a filter output related to a filtered value of the process signal. A second statistical parameter module provides a second statistical parameter output related to a statistical parameter of the filter output. A diagnostic module diagnoses operation of the industrial process based upon the first and second statistical parameters.

Claims

1. A device for diagnosing operation of an industrial process control or monitoring system, comprising:

an input configured to receive an input related to a process signal;

a first statistical parameter module configured to provide a first statistical parameter output related to a statistical parameter of the process signal;

a filter configured to provide a filter output related to a filtered value of the process signal;

a second statistical parameter module configured to provide a second statistical parameter output related to a statistical parameter of the filter output; and

a diagnostic module configured diagnose operation of the industrial process based upon the first and the second statistical parameters.

2. The apparatus of claim 1 wherein the filter is configured to trim data from the input data.

3. The apparatus of claim 2 wherein the filter is configured to remove outliers in the data.

4. The apparatus of claim 2 wherein the filter is configured to remove data based upon a comparison of the data with a moving average.

5. The apparatus of claim 2 wherein the filter is configured to remove data spikes in the data.

6. The apparatus of claim 1 wherein the first and second statistical parameters are selected from the group of statistical parameters consisting of minimum, maximum, range, mean, root mean squared and standard deviation.

7. The apparatus of claim 1 wherein the filter comprises a low pass filter.

8. The apparatus of claim 1 wherein the filter comprises a band pass filter.

9. The apparatus of claim 1 wherein the filter comprises a high pass filter.

10. The apparatus of claim 1 wherein the filter comprises a custom filter.

11. The apparatus of claim 10 wherein the custom filter is based upon a received parameter.

12. The apparatus of claim 1 including a second input configured to receive a second input related to a second process signal and wherein the diagnostic module diagnoses operation of the industrial process further based upon the second process signal.

13. The apparatus of claim 1 wherein the diagnostic module is configured to diagnose operation of the industrial process further based upon a rule.

14. The apparatus of claim 1 wherein the diagnostic module is configured to diagnose operation of the industrial process further based upon a sensitivity parameter.

15. The apparatus of claim 1 including an input/output connection coupled to a process control loop.

16. The apparatus of claim 15 wherein power for the device is received from a process control loop.

17. The apparatus of claim 1 including a sensor configured to provide an output related to a sensed process variable on a two-wire process control loop.

18. The apparatus of claim 1 including a control element configured to control a process variable and input configured to receive a control signal from a two-wire process control loop.

19. The apparatus of claim 1 wherein the filter includes a plurality of selectable filter functions.

20. The apparatus of claim 1 wherein the filter comprises a difference filter.

29. The method of claim 20 wherein filtering comprises applying a difference filter.

21. A method for diagnosing operation of an industrial process or monitoring system, comprising:

receiving an input related to a process signal;

calculating a first statistical parameter related to a statistical parameter of the process signal;

filtering the process variable signal to provide a filtered value of the process signal;

calculating a second statistical parameter based upon the filtered value of the process signal; and

diagnosing operation of the industrial process based upon the first statistical parameter and the second statistical parameter.

22. The method of claim 21 wherein the filter is configured to trim data from the input data.

23. The method of claim 22 wherein the filter is configured to remove outliers in the data.

24. The method of claim 22 wherein the filter is configured to remove data based upon a comparison of the data with a moving average.

25. The method of claim 22 wherein the filter is configured to remove data spikes in the data.

26. The method of claim 21 wherein the first and second statistical parameters are selected from the group of statistical parameters consisting of minimum, maximum, range, mean, root mean squared and standard deviation.

27. The method of claim 21 wherein the filter is selected from the group of filters consisting of low pass, high pass and band pass filter.

28. The method of claim 21 including selecting a filter function in a filter module which includes a plurality of filter functions.

30. A device for diagnosing operation of industrial process control or monitoring system, comprising:

an input configured to receive an input related to a process signal;

a difference filter configured to provide a difference output based upon a current value of the input and the previous value of the input;

a diagnostic module configured to diagnose operation of the industrial process based upon an output from the difference filter.

31. The apparatus of claim 30 wherein the difference filter comprises a first order difference filter.