Method and apparatus for diagnosing pneumatic control valve by using positioner model
US11378108B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2017 |
| Grant date | Jul 5, 2022 |
| Priority date | — |
| Expiry date | Aug 25, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/45006
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Method for diagnosing a pneumatic control valve by using a positioner model includes: establishing relational expression for outputting valve stem displacement according to control pressure, the relational expression including parameters for the characteristics of a positioner, an actuator, and a valve, determining initial parameter value by adjusting the values of the parameters until the difference between a measured value for a normal operation of the pneumatic control valve and output value obtained by the relational expression is smaller than predetermined error limit, determining diagnostic parameter value by adjusting the values of the parameters until the difference between a measured value for a diagnostic operation of the pneumatic control valve and an output value obtained by the relational expression is smaller than a predetermined error limit, and comparing the initial parameter value and the diagnostic parameter value so as to determine whether the pneumatic control valve has abnormality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.