Off-line diagnosis system

• US 6,941,244 B1
• Filed: 09/18/2003
• Issued: 09/06/2005
• Est. Priority Date: 09/30/2002
• Status: Expired due to Term

• Current Assignee: Dresser, LLC (GE Aerospace), Yokogawa Electric Corporation
• Original Assignee: Dresser Incorporated (Nagano Keiki Company Limited)
• Inventors: Saito, Yoji, Du, Hongli, Hashizumi, Kazuhiro, Legere, Alex
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US10/665,791
• Time in Patent Office: 719 Days
• Field of Search: 702/31, 702/32, 702/33, 702/81, 702/182, 702/183, 702/186, 702/187, 702/188, 700/83, 700/104, 700/117, 700/275, 700/280, 706/60
• US Class Current: 702/183
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G05B 2219/31211 Communicate diagnostic data from intelligent field device controller to central
• CPC Class Codes: G05B 2219/33326 Analyzer, diagnostic for servovalve
• CPC Class Codes: G05B 2219/33331 Test, diagnostic of field device for correct device, correct parameters
• CPC Class Codes: G05B 23/021 adopting a different treatment of each operating region or a different mode of the monitored system, e.g. transient modes; different operating configurations of monitored system
• 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 23/0256 injecting test signals and analyzing monitored process response, e.g. injecting the test signal while interrupting the normal operation of the monitored system; superimposing the test signal onto a control signal during normal operation of the monitored system
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Process control systems may include one or more diagnostic systems and/or processes. In particular implementations, a diagnostic system and process for a field instrument may include the ability to divide a signal input range into a plurality of zones with respect to an input axis or a time axis, measure input response characteristics for a zone with the field instrument, and store measurement data points for the zone in memory of the field instrument. The diagnostic system and process may also include the ability to transmit the measurement data points for the zone to a host application and, while transmitting the measurement data points for the zone, measure input response characteristics for a second zone with the field instrument.

Claims

1. An off-line diagnosis system comprising:

a field instrument for use in a process control system, the instrument having capability to perform, during an off-line interval, a diagnosis function over a signal input range, wherein the diagnosis function is one of a self-diagnosis function and a valve diagnosis function, and the signal input range is divided into a plurality of zones with respect to an input axis or a time axis; and

a host application in digital communication with the field instrument, wherein diagnosis results of each zone are successively transmitted to the host application.

2. The system of claim 1, wherein the field instrument comprises memory of a predetermined capacity having diagnosis results of one zone stored therein, and the field instrument is adapted to transmit to the host application diagnosis results of the one zone while storing in memory diagnosis results of another zone.

3. The system of claim 1, wherein the diagnosis function is based on input-output characteristics measurement, wherein an input is given to the object being diagnosed and then an output value thereof is measured.

4. The system of claim 1, wherein the diagnosis is based on a step input given to the object being diagnosed.

5. The system of claim 1, wherein the field instrument is a valve positioner.

6. The system of claim 1, wherein the field instrument is an electro-pneumatic converter.

7. A diagnosis system comprising:

a field instrument for use in a process control system, the instrument adapted to perform a diagnosis function during an off-line interval including dividing a signal input range into a plurality of zones with respect to a time axis and successively measuring diagnosis results for each zone; and

a host application digitally coupled to the field instrument to receive the diagnosis results for each zone of the plurality of zones, wherein the field instrument successively communicates diagnosis results for each zone to the host application.

8. The system of claim 7, wherein the field instrument comprises memory having maximum capacity for a predetermined number of data measurement points and the number of data points measured for each zone equal the predetermined number.

9. The system of claim 7, wherein the field instrument is a valve positioner.

10. The system of claim 7, wherein the field instrument is an electro-pneumatic converter.

11. The system of claim 7, wherein the diagnosis function is a self-diagnosis function.

12. The system of claim 7, wherein the diagnosis function is a valve diagnosis.

13. A method of improving diagnosis resolution in a field instrument of a process control, the method comprising:

dividing a signal input range into a plurality of zones with respect to an input axis or a time axis;

measuring with the field instrument input response characteristics for each zone, including storing data point measurements for each zone in memory of a predetermined capacity of the field instrument; and

successively communicating the data point measurements for each zone to memory of a host application in digital communication with the field instrument, wherein the number of data point measurements communicated to the host application is greater than the capacity of the memory of the field instrument.

14. The method of claim 13, wherein measuring input response characteristics comprises measuring step input characteristics.

15. A method of improving diagnosis resolution in a field instrument of a process control, the method comprising:

dividing a signal input range into a plurality of zones with respect to an input axis or a time axis;

measuring input response characteristics for a zone with the field instrument;

storing measurement data points for the zone in memory of the field instrument;

transmitting the measurement data points for the zone to a host application; and

while transmitting the measurement data points for the zone, measuring input response characteristics for a second zone with the field instrument.

16. The method of claim 15, comprising successively transmitting the data measurement points for all the plurality of zones to the host application.

17. A method of performing a valve diagnosis with a valve positioner, comprising:

dividing a signal input range into a plurality of zones with respect to a time axis;

measuring input response characteristics for each zone with the valve positioner;

successively storing data point measurements for each zone in memory of the valve positioner; and

successively communicating the data point measurements for each zone to memory of a host application in digital communication with the valve positioner.

18. A method of performing a self-diagnosis with a valve positioner, comprising:

dividing a signal input range into a plurality of zones with respect to a time axis;

measuring input response characteristics for each zone with the valve positioning; and

successively storing and communicating data point measurements for each zone to memory of a host application, wherein the valve positioner transmits the data point measurements for one of the plurality of zones to the host application while measuring the data points for a successive zone of the plurality of zones.