| 摘要 |
PURPOSE:To realize the automatic operation of a plant by using the output of an operating means or the output of another correlative detector as a substitute signal when the abnormality of the output of a certain detector lasts longer than a prescribed period of time. CONSTITUTION:The value corresponding to the sampling value of this time and the prescribed value are calculated by the minimum square method using the paste detector outputs and the regression linear approximation and in consideration of the dynamic properties. These calculated value and prescribed value are compared with the current sampling value for detection of the abnormality of the detector output. If the abnormality of output lasts longer than a prescribed period of times with detectors 4-7, an abnormality detecting means functions to substitute the abnormal detector output for the outputs of operating means 2 and 3 serving as the substitute signals decided normal or the output of another correlative detector. For this purpose, the signals undergone the advance/delay compensation and the correlative compensation processing are changed to the bumpless states by bumpless switches 16 and 26 as long as the deviations of those signals are kept under the prescribed value. Thus it is possible to prevent the influence given to a control system owing to the continuation of the automatic control especially the malfunctions of the control system and also to avoid the increase of the operator load and misoperations.
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