| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a valve positioner capable of obtaining sufficient response even when a characteristic of a valve varies.SOLUTION: A valve positioner having an auto-tuning function 7 for determining a control parameter of a valve 5 comprises: parameter table creation means for creating a parameter table with a control parameter after auto-tuning as a reference; a memory for storing the parameter table created by the parameter table creation means; response change observation means 9 for observing response change of the valve 5; and parameter selection means 10 for estimating a state of a packing of the valve 5 on the basis of observing results of the response change observation means, and selecting a proper control parameter from the parameter table stored in the memory to set it to the valve 5.</p> |
