JP3108546B2 - Detector redundancy system error handling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detector redundant system abnormality processing apparatus which can be used in various industrial fields such as pulp and paper, steel, petroleum refining, petrochemical, food, medicine, water supply, electric power, cement and the like.

[0002]

2. Description of the Related Art In the prior art, when two or more detectors are installed at the same measurement point, simple switching based on a one-system abnormal signal is performed. Therefore, the signal switching when the detector is abnormal has a problem not only in bumpless but also in control calculation.

[0003]

SUMMARY OF THE INVENTION In the present invention, when two or more detectors are installed at the same measurement point, the object of the present invention is to smooth the measurement signal and to switch the bumpless measurement signal when one system is abnormal. I do.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a system is provided which is connected to a detector of a redundant system, receives a past measured signal value and a present measured signal value, and shifts a time-varying system detected value. A moving average circuit for calculating an average value, and a signal switching circuit for determining an abnormal state by determining whether an output value of the moving average circuit is within a predetermined range and switching and connecting the output circuit of the moving average circuit. An arithmetic averaging circuit connected to a plurality of series circuits each including a moving average circuit and a signal switching circuit and inputting a plurality of moving average values, and calculating an arithmetic average value of the plurality of moving average values; and A plurality of signal inverting circuits connected to the auxiliary circuit, inputting a corresponding signal value corresponding to a past measured signal value or a current measured signal value, inverting and outputting the corresponding signal value, and a plurality of signal inverting circuits. Output signal logic A logical OR circuit for calculating an a detector redundancy system abnormality processing apparatus formed by and a change rate limiting circuit for controlling the rate of change in the output value of the arithmetic mean circuit by an output signal of the OR circuit.

[0005]

According to the detector redundant system abnormality processing apparatus of the present invention, a system which is connected to a detector of a redundant system, receives a past measured signal value and a present measured signal value, and changes the temporally changed system signal value. Calculating a moving average of the detected values, determining an abnormal state by determining whether an output value of the moving average circuit is within a predetermined range, switching and connecting the output circuit of the moving average circuit, and Arithmetic averaging circuit is connected to a plurality of series circuits consisting of a circuit and a signal switching circuit, and a plurality of moving average values are inputted, an arithmetic average value of a plurality of moving average values is calculated, and a signal is inverted to an auxiliary circuit of the detector. Connect the circuit, input the corresponding signal value corresponding to the past measurement signal value or the current measurement signal value, invert the corresponding signal value and output, and calculate the logical sum of the output signals from multiple signal inversion circuits To the output signal of the OR circuit. Limiting the rate of change in the output value of the arithmetic mean circuit I.

[0006]

Next, an embodiment of the present invention will be described. In FIG. 1, reference numerals 1 and 2 are connected to detectors of a redundant system to measure a past measured signal value AI1 and a current measured signal value AI1A.
, And a moving average circuit 3 for calculating a moving average value of the system detection value that has changed over time.
An abnormal state is determined based on whether or not the output value of the moving average circuit 1 is within a predetermined range.
An arithmetic averaging circuit which is connected to a plurality of series circuits composed of a circuit 2 and signal switching circuits 3 and 4 and receives a plurality of moving average values and calculates an arithmetic average of the plurality of moving average values; , A plurality of signal inverting circuits for inputting corresponding signal values AI1A and AI2A corresponding to past measured signal values or current measured signal values, inverting corresponding signal values, and outputting the inverted signal values. An OR circuit 9 for calculating the OR of the output signals from the signal inverting circuits 6 and 7; a change rate limiting circuit 9 for limiting the change rate of the output value of the arithmetic averaging circuit 5 by the output signal of the OR circuit 8; When two or more detectors are installed at the same measurement point, moving average circuits 1 and 2 that perform moving average processing of a measurement signal, and a signal switch 3 that separates an abnormal signal when a detector (measurement signal) is abnormal. 4 and average processing of two or more measurement signals. The arithmetic mean circuit 5, a signal inverting circuit 6 which inverts the detector (measurement signal) normal / abnormal signal,
This is a detector redundancy system abnormality processing device comprising a change rate limiting circuit 9 for limiting a change rate to the arithmetic averaging circuit 5 when a detector (measurement signal) is abnormal.

In this embodiment, moving average (MAV) and arithmetic averaging are used to smooth the measurement signal, and the change rate limit (ΔL
M) is used.

The moving average (MAV) is calculated based on the analog input (A
I1, AI2) is the average of the past and present data, and the arithmetic average is the moving averaged analog input AI1, AI2.
Is the average of Both are aimed at smoothing the measurement signal (analog input).

The rate-of-change limit (ΔLM) is calculated based on the arithmetic mean (AV
E) limits the rate of change of the output and operates only when an analog input is abnormal.

FIG. 1 is a block diagram of an abnormality processing apparatus for a detector redundancy system according to the present invention, and FIG. 2 is a block diagram of a detector normality determination related to the present invention.

The moving average circuits 1 and 2 shown in FIG. 1 have a function of moving average, and average the past and present data of the measurement signals (analog input) AI1 and AI2. Signal switch 3, 4
Is a switch for the measurement signal after the moving average, and if the measurement signal is abnormal, disconnects the abnormal signal. The arithmetic averaging circuit 5 is a function of arithmetic averaging of the measurement signal after the moving average,
Normally, this is the average of two signals, but when one system is abnormal, the average is only the normal system. The signal inverting circuits 6 and 7 have a signal inverting function, and the OR circuit 8 has an OR operation function.
The rate-of-change limiting circuit 9 is a rate-of-change limiting function, and limits the rate of change when a measurement signal is abnormal.

The moving averaging circuits 1 and 2 output the measurement signal Nos.
The moving average processing of 1 and 2 is performed. The moving average is the average of one or more past measurement signals and the current measurement signal, and the number of past measurement signals is selected according to the type of the measurement signal (temperature, pressure, flow rate, component, etc.). The conditions for moving average are
Each measurement signal is normal.

When the measurement signals are normal, the signal switches 3 and 4 select the corresponding measurement signals. However, when the measurement signals are abnormal, the signal switches are switched to the normal measurement signal side to eliminate the abnormal signals. Arithmetic averaging (AVE) of the arithmetic averaging circuit 5 is for correcting variations between measurement signals.

The change rate limiter 9 prevents the arithmetic average value of the arithmetic average circuit 5 from changing suddenly when the measurement signal is abnormal.

FIG. 2 is a block diagram of a detector for determining whether or not a measurement signal is normal. The detector is normal because the measurement signals 21 and 22
Is 0.7V or more and 5.12V or less, otherwise, it is determined to be abnormal.

[0016]

According to the invention of the present invention, two detectors are set at the same measurement point.
If more than one unit is installed, even if one of the systems becomes abnormal, the control variables do not change suddenly, and the effect of smoothing the variables is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an abnormality processing apparatus for a redundant detector system according to the present invention.

FIG. 2 is an explanatory diagram of a detector normal determination block diagram of a measurement signal.

[Explanation of symbols]

 1, 2, moving average circuit 3, 4, signal switcher 5, arithmetic averaging circuit 6, 7, signal inversion circuit 8, OR circuit 9, change rate limiting circuit

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-153422 (JP, A) JP-A-3-81618 (JP, A) JP-A-5-53658 (JP, A) JP-A-63-153 263416 (JP, A) JP-A-56-135108 (JP, A) JP-A-57-81602 (JP, A) JP-A-62-174801 (JP, A) JP-A-61-103201 (JP, A) JP-B 64-2203 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01D 21/00 G05B 7/02 G05B 9/03 G05B 11/36 503

Claims (1)

(57) [Claims] A moving average circuit which is connected to a detector of a redundant system, receives a past measured signal value and a present measured signal value, and calculates a moving average value of a temporally changed system detected value. And, determine the abnormal state by whether the output value of this moving average circuit is within a predetermined range,
A signal switching circuit that switches and connects an output circuit of the moving average circuit; and a plurality of moving average values that are connected to a plurality of series circuits including the moving average circuit and the signal switching circuit and input the plurality of moving average values. An arithmetic averaging circuit for calculating an arithmetic average value of the average value, connected to an auxiliary circuit of the detector,
A plurality of signal inverting circuits for inputting corresponding signal values corresponding to the past measured signal values or the present measured signal values, inverting and outputting the corresponding signal values, and output signals from the plurality of signal inverting circuits A logical sum circuit for calculating the logical sum of
A change rate limiting circuit for limiting a change rate of an output value of the arithmetic averaging circuit by an output signal of the OR circuit, and