| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily and accurately diagnose abnormality of a control valve in process operation. <P>SOLUTION: Actuator pressure Po to a control valve 200 and an opening extent X from the control valve 200 are sampled, a speed vPo(k) of change in current Po(k) is found from the current Po(k) and last Po(k-1), and a speed vX(k) of change in current X(k) is found from the current X(k) and last X(k-1). A weight w1(k) is set to 1 only when vPo(k) and vX(k) are both small (or to 0 when not), and an abnormality diagnostic index Fq (i) of each opening extent category (i) in an abnormality diagnostic determination period is found from vPo(k) and vX(k) when w1(k) is 1, and a linear approximation expression showing static input/output relation of the control valve 200 in normal operation. <P>COPYRIGHT: (C)2013,JPO&INPIT |
