초록 ▼

A fault-detecting apparatus comprises a model simulating the input-output characteristics of an object for fault detection. The model includes statics and dynamics and is impressed with the same input as the object for fault detection. The output of the model is compared with the output of the objec

A fault-detecting apparatus comprises a model simulating the input-output characteristics of an object for fault detection. The model includes statics and dynamics and is impressed with the same input as the object for fault detection. The output of the model is compared with the output of the object for fault detection, and if the deviation is great, it is indicated that a fault has generated in the object for fault detection. In order to determine whether or not correction of the model is possible, the degree of the deviation is determined from an average value of the time-series signals produced from various parts of the fault-detecting apparatus during a certain period of time. For this purpose, a variation is calculated, for example; and if it is smaller than a predetermined value VL, a normal condition is judged and the statics correction is considered possible, while if the variation is larger than VH (which in turn is larger than VL), a transient condition is judged, and the dynamics correction is considered possible. Correction of the characteristics is effected by processing the data applied to the fault-detecting apparatus for the previous certain period of time.

대표청구항 ▼

In a fault-detecting apparatus (8) for a closed-loop control system (1, 2 and 3) having an object for fault detection which makes up part of said control system, said apparatus being supplied with digital signals obtained by sampling input and output of said object with a fixed periodic time, and de

In a fault-detecting apparatus (8) for a closed-loop control system (1, 2 and 3) having an object for fault detection which makes up part of said control system, said apparatus being supplied with digital signals obtained by sampling input and output of said object with a fixed periodic time, and detecting an abnormal state of said object on the basis of said digital signals so as to notify the occurrence of said abnormal state, said apparatus (8) comprising: mathematical model means (B4-B10) simulating an input-output characteristic of said object included in said control system (1, 2 and 3), said model means being supplied with the digital signals corresponding to the input of said object with every sampling, and generating the digital signals corresponding to the output of said object; first means (B11-B15) for comparing the output of said model means with the output of said object with every sampling, and for detecting an abnormal state of said object so as to notify the occurrence of the abnormal state; second means (B17-B30) for receiving time-series digital signals relating to one of input and output of said object for a predetermined period when the presence of a model correction signal is confirmed, for determining an average value of said time-series digital signals received during the predetermined period, and for generating a signal corresponding to the degree of the deviation of said time-series digital signals from said average value; third means (B31) for determining whether or not the correction of the characteristic of said model means is possible, on the basis of said signal corresponding to the degree of the deviation; fourth means (B33-B45) for correcting the characteristic of said model means on the basis of said time-series digital signal received during the same period as said predetermined period of said second means when said third means decides that the correction is possible,