| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress false detection of stick-slip with a high degree of accuracy. <P>SOLUTION: A stick-slip detector executes the steps of: calculating a first state quantity and a second state quantity on the basis of valve stem displacement; using a first stick-slip index calculation part 14 to obtain a ratio between the first and second state quantities as a first stick-slip index SSpv; calculating a third state quantity and a fourth state quantity on the basis of a control order value of the valve stem displacement; using a second stick-slip index calculation part 24 to obtain a ratio between the third and fourth state quantities as a second stick-slip index SSsp; and using an abnormality determination part 30 to determine that the stick-slip occurs when satisfying a conditional expression "SSpv>Th AND SSpv>α(SSsp+β)" with setting a threshold as Th, setting a first constant as α and setting a second constant as β. <P>COPYRIGHT: (C)2013,JPO&INPIT |
