Condition monitoring of electrical cables as installed in industrial processes

• US 7,478,010 B2
• Filed: 07/23/2007
• Issued: 01/13/2009
• Est. Priority Date: 05/14/2002
• Status: Expired due to Term

• Current Assignee: Analysis And Measurement Services Corporation
• Original Assignee: Analysis And Measurement Services Corporation
• Inventors: Hashemian, Hashem M.
• Primary Examiner(s): Raymond; Edward
• Application Number:
  US11/781,351
• Publication Number:
  US 20080015817A1
• Time in Patent Office: 540 Days
• Field of Search: 702/151, 702/183, 702 57- 59, 702/118, 702/121, 702/182, 702/185, 702/199, 700/9, 700/21, 700/29, 700/49, 700/108, 700/110, 700/174
• US Class Current: 702/151
• CPC Class Codes: G05B 23/0283 Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06

Abstract

A system and method for verifying the performance and health of wire systems and end devices, including instruments and processes. A computer runs software that collects data from sampled sensors, stores the data, screens the data for outliers, analyzes the data, performs in situ testing, and generates results of the analysis and testing. The system and method verifies not only the steady state performance of instruments, but also the dynamic performance of instruments and the transient behavior of the processes. In one embodiment, the system performs testing of the wiring system connecting the end devices located at the process. In another embodiment, the system also performs analysis of the amplitude probability density and a power spectral density determined from the sensor, or end device, data. In still another embodiment, the system performs a time domain reflectometry (TDR) analysis for a wiring system connecting an end device.

Claims

1. A method for verifying the performance and health of a plurality of instruments and processes, said method comprising:

sampling data from a plurality of sensors, said sampled data corresponding to a plurality of signals each representing an output from one of said plurality of sensors;

storing said sampled data;

analyzing said sampled data, said step of analyzing including performing at least one analysis selected from a group including an analysis of an amplitude probability density, an analysis of a power spectral density, and an analysis of a time domain reflectometry;

using said analysis results to determine whether a corrective action is required; and

initiating said corrective action automatically when said step of using said analysis results determines said corrective action is required.

2. The method of claim 1 wherein said step of analyzing includes performing at least one of a static analysis and a dynamic analysis.

3. The method of claim 1 wherein said step of analyzing includes performing a static analysis and a dynamic analysis.

4. The method of claim 1 further including a step of screening said sampled data after said step of sampling data.

5. The method of claim 1 wherein said corrective action includes at least one of an instrument calibration and an in situ test.

6. A method for verifying the performance and health of a plurality of instruments and processes, said method comprising the steps of:

sampling data from a plurality of sensors associated with the plurality of instruments and processes to produce sampled data, said sampled data corresponding to a plurality of signals each representing an output from one of said plurality of sensors;

storing said sampled data;

qualifying said sampled data to determine whether said sampled data is an outlier;

initiating a first corrective action when said step of qualifying said sampled data determines said sampled data is an outlier;

analyzing said sampled data to produce analysis results when said step of qualifying said sampled data determines said sampled data is not an outlier, said step of analyzing said sampled data including performing at least one analysis selected from a group including an analysis of an amplitude probability density, an analysis of a power spectral density, and an analysis of a time domain reflectometry;

using said analysis results to determine whether a second corrective action is required; and

initiating said second corrective action when said step of using said analysis results determines said second corrective action is required.

7. The method of claim 6 wherein said first corrective action includes at least one of discarding said sampled data, performing a calibration, and initiating in-situ testing.

8. The method of claim 6 wherein said second corrective action includes at least one of performing a calibration and initiating in-situ testing.

9. The method of claim 6 further comprising the step of reporting said analysis results.

10. The method of claim 6 wherein said step of analyzing said sampled data further comprises the steps of:

estimating a process value from said sampled data; and

identifying the deviation of each instrument channel from said estimated process value.

11. The method of claim 6 wherein said step of analyzing said sampled data further comprises the steps of

using a plurality of data analysis techniques to produce a plurality of interim results;

averaging said interim results to produce said analysis results.

12. The method of claim 10 wherein said plurality of data analysis techniques includes static analysis, dynamic response analysis, and transient process analysis.