JPH0829212A - Processor for abnormality in detector redundancy system - Google Patents

Abstract

PURPOSE:To enable switching bumpless transfer for omitting output value in abnormal generation by limiting the change rate of sending measured value. CONSTITUTION:An abnormality judgment part 8 transmits No.1 input abnormal signal AI1AB when it detects an abnormality with a measured value AI1. Receiving this, No.1 signal reverser 9 reverses the signal from 1 to 0 and makes the measured value AI1 unable to use in calculating moving average with the No.1 moving average circuit 2. Also, it turns on No.1 switcher 4 to shut off the input from the circuit 2 to an arithmetic mean circuit 6 and, instead of that, send the output of No.2 moving average circuit 3 to the circuit 6 through the switcher 4. On the other hand, an OR circuit 10 receives the signal AI1AB and outputs change rate limit signal to a change rate limit circuit 7. The circuit 7 temporarily provides the change rate with a limit so that the output value from the circuit 6 does not change quickly. Thus, the measured value PV does not change suddenly. In the case of No.2 detector abnormality, it also functions in the same manner with the No.2 system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detector used in all industrial fields such as paper pulp, steel, petroleum refining, petrochemicals, foods, chemicals, water, electric power, cement, etc. The present invention relates to an abnormality processing device of a detector redundancy system that performs processing when an abnormality occurs when the vessels are made redundant.

[0002]

2. Description of the Related Art For example, it is widely practiced to install a plurality of detectors at a measurement point of a controlled object such as various plants in case of abnormality of the detectors. The detector redundancy system having such redundancy is equipped with a simple switching device as an abnormality processing device when an abnormality occurs in one detector.

FIG. 3 shows an abnormality processing block diagram in an abnormality processing device of a conventional detector redundancy system, and FIG. 4 shows an abnormality determination block diagram in an abnormality processing device of a conventional detector redundancy system.

In FIG. 3, two detectors, NO1 and NO2, output analog signals of 1 to 5 VDC, respectively, and these signals are detected as an analog NO1 input AI1 and an analog NO2 input AI2 and the detector redundancy system is abnormal. It is input to the processing device 41.

In a normal state, the detector switch 42 is in an off state and is connected to the input AI1 side. In this state, the output of the NO1 detector is the measured value P as shown in FIG.
Sent as V. Next, it is determined that the NO1 detector is abnormal, and the abnormality determiner 43 is input to the switch.
When the NO1 inactive signal AI1I is turned on, the switch 42 is turned on. Therefore, the NO1 detector is disconnected, and the output of the NO2 detector changes to the measured value P.
It will be transmitted as V.

On the other hand, the block diagram of the abnormality determiner 43 is shown in FIG.
It is as shown in. In FIG. 4, the analog NO1 input AI1 from the NO1 detector is input to the small determiner 44 and the large determiner 45. Inside the small discriminator 44,
It is determined whether or not the analog NO1 input AI1 is smaller than 0.7V. If the analog NO1 input AI1 is smaller than 0.7V, it is determined that an abnormality has occurred and the signal is ORed.
It is sent to the circuit 46. Similarly, inside the large discriminator 45, it is judged whether or not the analog NO1 input AI1 is larger than 5.1 V, and if it is larger, a signal is sent to the OR circuit 46 that an abnormality has occurred. When a signal is input to the OR circuit 46, it is determined that the NO1 detector is out of the allowable range, that is, an abnormality has occurred, and the NO1 inactive signal AI1 is detected.
I is sent out.

[0007]

However, the method of suddenly switching from one detector to the other as described above cannot maintain the continuity of the measured value PV when the detector is switched. That is, bumpless switching cannot be performed. For example, when the measured value PV is used as a control amount in the process control device, such a discontinuous change in the control amount, which is different from the actual situation, adversely affects the control of the process.

Further, in the conventional abnormality judging device, it is judged to be abnormal when the analog output of the detector is deviated from 1 to 5V, but when the analog output of the detector is within 1 to 5V. However, for example, the analog output value is 1V
And 5V, either detector is clearly abnormal. However, the conventional abnormality processing device of the detector redundancy system has a problem that the abnormality determination and the detector switching cannot be performed in such a case.

The present invention has been made in consideration of such a situation, and a first object of the present invention is to provide a detector redundancy system for switching a detector to bumpless when an abnormality occurs in the detector. An object of the present invention is to provide an abnormality processing device, and a second object thereof is to provide an abnormality processing device of a detector redundancy system that reliably detects an abnormality even within an allowable range of the detector output. is there.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 determines and sends a measured value based on each output value of a plurality of detectors for measuring the same measuring object. In addition, when at least one output value among the output values is determined to be abnormal by the abnormality determining means,
The rate of change that suppresses the amount of change over time in the measured value that is being sent when the abnormal output value of the detector redundancy system is excluded from the target for determining the measured value. It is an abnormality processing device of a detector redundancy system provided with a limiting means.

The invention according to claim 2 is the invention according to claim 1, in which the measured value is calculated as a time-dependent moving average value for each of the output values, and the calculated time is calculated. It is an abnormality processing device of a detector redundancy system determined by averaging moving averages.

The invention according to claim 3 determines and sends a measured value based on each output value of a plurality of detectors for measuring the same measuring object, and outputs at least one of the output values. When the value is determined to be abnormal by the abnormality determination means, the output value of the detector is set in advance in the abnormality processing device of the detector redundancy system that excludes the corresponding output value from the target for determining the measurement value. Output difference determination means for determining whether or not the output difference is greater than or equal to a predetermined value, and output change determination for determining whether or not the rate of change of each output value of the detector with respect to time is greater than or equal to a preset value. The output change determining means determines that a certain detector has changed more than a preset value, and the output difference determining means determines that the difference between the output values is equal to or more than the set value. When done, The output value of the detector is abnormal processing apparatus of the detector redundancy system provided with the abnormality determination means determines that there is an abnormality.

[0013]

Therefore, first, in the abnormality processing apparatus of the detector redundancy system of the invention according to claim 1, the abnormality determination means determines that a certain detector output is abnormal,
When the output value is separated from the sent measurement value, the rate of change of the sent measurement value is limited by the change rate limiting means so that the sent measurement value does not change abruptly. Therefore, it is possible to realize bumpless switching of measured values even if an abnormality occurs in a certain detector.

In addition, in the abnormality processing device of the detector redundancy system of the invention according to claim 2, in addition to the same operation as that of the invention according to claim 1, the transmitted measured value is the output value. Is calculated by further averaging the temporal moving average of.

Further, in the abnormality processing device of the detector redundancy system according to the third aspect of the present invention, the output difference determination means determines that the difference between the output values of the detectors is equal to or more than a preset value. In this case, and when the output change determination means changes the output of a certain detector at a change rate equal to or higher than a preset change rate, that is, when the output changes abruptly, it is detected that the output from the detector is abnormal. It Therefore, for example, if the abnormality detecting means is combined with the abnormality detecting means for determining the outside of the conventional allowable range, the above detection can be performed very effectively.

[0016]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the abnormality processing device of the detector redundancy system of this embodiment, and FIG. 2 shows the configuration of the abnormality determination unit in the abnormality processing device of the detector redundancy system of this embodiment. It is a block diagram.

NO (not shown) for measuring the same measuring object
Analog signals of 1 to 5 VDC are output from the two detectors 1 and NO2, respectively, and these signals are input to the abnormality processing device 1 of the detector redundancy system as the NO1 measurement signal AI1 and the NO2 measurement signal AI2. There is.

First, in FIG. 1, the NO1 measurement signal AI
The 1 and NO2 measurement signals AI2 are input to the NO1 moving average circuit 2 and the NO2 moving average circuit 3, respectively, and then the respective moving averages are output to the NO1 switch 4 or the NO2 switch 5.
Is input to the arithmetic averaging circuit 6 after passing through, or is output as the measured value PV via the change rate limiting circuit 7.

On the other hand, NO1 measurement signals AI1 and NO2
The measurement signal AI2 is input to the abnormality determination unit 8. When the NO1 detector is abnormal, the abnormality determining unit 8 outputs the NO1 input abnormal signal AI1AB to the NO1 signal inverting unit 9, the NO1 switch 4 and the OR circuit 10. Further, when the NO2 detector is abnormal, the NO2 input abnormal signal AI2AB is similarly output from the abnormality determining unit 8 to the NO2 signal inverting unit 11 and NO2.
It is output to the switch 5 and the OR circuit 10. Furthermore, O
When receiving the abnormal signal, the R circuit 10 issues a change rate limiting signal to the change rate limiting circuit 7.

The NO1 moving average circuit 2 calculates the average of the current and past data of the NO1 measurement signal AI1, that is, the moving average, and the NO1 switching unit 4 and the NO2 switching unit 5 are operated.
Send to. Here, the NO1 signal inversion unit 9 is used for the moving average.
Is multiplied by the output from. Therefore, the moving average is multiplied by 0 when the NO1 input abnormality signal AI1AB is transmitted, and when it is not transmitted. Further, the NO2 moving average circuit 3 functions similarly to the NO1 moving average circuit 2 with respect to the NO2 measurement signal AI2 and the NO2 input abnormality signal AI2AB.

Further, the NO1 switch 4 is supplied with the respective moving averages from the NO1 moving average circuit 2 and the NO2 moving average circuit 3, and the NO1 switch 4 is NO.
N when 1-input abnormal signal AI1AB is not sent
The moving average of the O1 moving average circuit 2 is sent to the arithmetic average circuit 6 when the NO1 input abnormality signal AI1AB is sent. Conversely, NO
When the NO2 input abnormality signal AI2AB is not sent out, the 2 switch 5 calculates the moving average of the NO2 moving average circuit 3,
When the NO2 input abnormality signal AI2AB is sent, the moving average of the NO1 moving average circuit 2 is sent to the arithmetic average circuit 6.

Further, the arithmetic mean circuit 6 includes a NO1 switch 4
And the arithmetic mean of each output from the NO2 switch 4 is calculated and sent to the change rate limiting circuit 7. The rate-of-change limiting circuit 7 as the rate-of-change limiting means uses the NO1 input abnormal signal AI1A.
When the B or NO2 input abnormality signal AI2AB is transmitted, the rate-of-change limiting signal is received via the OR circuit 10, the rate of change of the arithmetic average is limited, and the measured value PV is transmitted.

Next, the configuration of the abnormality determining section 8 will be described with reference to FIG. In FIG. 2, the abnormality determination unit 8 includes a detection difference abnormality detection unit 12 as output difference determination means, a NO1 change rate large detection circuit 13 and a NO2 change rate large detection circuit 14 as output change determination means, and a detection difference abnormality. Detection unit 12 and NO1
The AND circuit 15 which ANDs the large change rate detection circuit 13 and outputs the NO1 input sudden change signal AI1D, the AND of the detection difference abnormality detection unit 12 and the NO2 large change rate detection circuit 14
AND that outputs NO2 input sudden change signal AI2D
Circuit 16, NO1 range abnormality detection circuit 17, NO2
It is composed of a range abnormality detection circuit 18, an OR circuit 19, and an OR circuit 20.

The NO1 input abnormality signal AI1AB, which is the output of the abnormality determination section 8, is output when the AND circuit 15 inputs the NO1 input sudden change signal AI1D or the NO1 range abnormality detection circuit 17 inputs the NO1 inactive signal AI1I. It Similarly, the NO2 input abnormality signal AI
2AB is the NO2 input sudden change signal AI from the AND circuit 16.
From the 2D or NO2 range abnormality detection circuit 18 to NO2
It is output when the inactive signal AI2I is input.

Further, the detection difference abnormality detection circuit 12 includes a subtraction circuit 21 for calculating the difference between the measurement signals AI1 and AI2, an absolute value circuit 22 for calculating the absolute value of the difference, and this absolute value being a set value or more. It is configured by a comparison circuit 23 that determines whether or not there is.

Further, the NO1 range abnormality detection circuit 17
Is a maximum value setter 24 that sets a maximum value for detecting a range abnormality, a minimum value setter 25 that sets a minimum value for detecting a range abnormality, and the NO1 measurement signal AI1 is larger than the maximum value. Large discriminator 26 that outputs a signal in the case
And a small decision unit 27 that outputs a signal when the NO1 measurement signal AI1 is smaller than the minimum value, and a signal is output from the large decision unit 26 or the small decision unit 27 to determine that the detector is abnormal. The OR circuit 28 outputs the NO1 inactive signal AI1I.

On the other hand, the NO2 range abnormality detection circuit 18 also
Similar to the NO1 range abnormality detection circuit 17, that is, the maximum value setting device 29, the minimum value setting device 30, and the large determination device 31.
It is composed of a small discriminator 32 and an OR circuit 33, and when it judges from the NO2 measurement signal AI2 that the detector is abnormal, it outputs the NO2 inactive signal AI2I.

Further, in this embodiment, the maximum value setting device 2
The maximum value set to 4, 29 is 5.1VDC, and the minimum value set to the minimum value setters 25 and 30 is 0.7V.
It is DC.

Next, the operation of the abnormality processing device of the detector redundancy system of this embodiment constructed as described above will be explained. First, when the abnormality determination unit 8 does not determine that the detector is abnormal, the abnormality processing device 1 of the detector redundancy system determines the moving average of the measured values AI1 and AI2 of the two detectors as NO1. The moving average circuit 2 and the NO2 moving average circuit 3 respectively calculate, and the moving average is further averaged by the arithmetic average circuit 6 to correct the variation between the detectors and then send it to the control system or the like.

Here, the number of past measurement signals for performing the moving average is selected according to the type of measurement signal (for example, temperature, pressure, flow rate, component, etc.). Next, for example, when an abnormality of the NO1 detector is detected by the measurement signal, the abnormality determination section 8 transmits the NO1 input abnormality signal AI1AB.

At this time, the signal from the NO1 signal inverting section 9 is inverted from 1 to 0, and the NO1 measured value AI1 is not used in the moving average calculation in the NO1 moving average circuit 2. Further, the NO1 switch 4 is turned on, the input from the NO1 moving average circuit 2 to the arithmetic average circuit 6 is cut off, and instead, the output from the NO2 moving average circuit 3 is sent to the arithmetic average circuit 6 via the NO1 switch 4. Is entered.

In this way, in the arithmetic mean circuit 6, N
Only the output from the O2 moving average circuit 3 results in arithmetic averaging. On the other hand, the OR circuit 10 outputs the change rate limiting signal to the change rate limiting circuit 7 by receiving the NO1 input abnormality signal AI1AB. The change rate limiting circuit 7
When this is received, the rate of change of the output value is temporarily limited so that the output value from the arithmetic mean circuit 6 does not change suddenly. Therefore, even if the values of the moving averages from the NO1 moving average circuit 2 and the NO2 moving average circuit 3 deviate to some extent before the occurrence of the abnormality, the value PV output to the control system or the like.
Does not cause sudden changes unrelated to the real process.

When an abnormality of the NO2 detector is detected by the measurement signal, the abnormality determining section 8 sends the NO2 input abnormality signal AI2AB, and so on. next,
The operation of the abnormality determination unit 8 will be described.

First, for example, a sudden change in the NO1 measurement value AI1 is detected by the NO1 change rate large detection circuit 13, and N
When the difference detection unit 12 determines that the difference between the O1 measurement value AI1 and the NO2 measurement value AI2 is equal to or greater than a certain value, the NO1 input sudden change signal AI1D is transmitted, and the NO1 input abnormality signal AI1AB is transmitted. .

The reason why abnormality is judged by such a logic is that one of the detectors is abnormal because the measured values of two detectors measuring the same measuring object are separated by a certain value or more. In addition, it is considered that the detector that caused the abrupt change in the measured value is abnormal.

Therefore, if the NO2 measurement value AI2 is judged in the same manner as described above, the NO2 input abnormality signal A
I2AB is transmitted. On the other hand, the conventional abnormality determination method of the detector by the deviation detection of the allowable range shown in FIG. 4 is still effective, so that the abnormality determination unit 8 of the present embodiment also has NO1.
Range abnormality detection circuits 17 and 18 are provided for the measured value AI1 and the NO2 measured value AI2, respectively, and when the NO1 inactive signal AI1I or the NO2 inactive signal AI2I is output from them, it is determined that an abnormality has occurred. , NO1 input abnormality signal AI1AB or NO2 input abnormality signal AI2AB is transmitted.

As described above, the abnormality processing device of the detector redundancy system according to this embodiment is provided with the moving average circuits 2 and 3, the switches 4 and 5, the arithmetic average circuit 6 and the change rate limiting circuit 7, Outputs the moving average and arithmetic average of the measured values of multiple detectors measuring the same measurement object to the control system, etc., and sends them by the change rate limiting circuit 7 even when an abnormality occurs in one detector. Since the measured value PV does not change abruptly, when the detector is normal, smoothed and averaged and more reliable measured values of a plurality of detectors can be sent, and an abnormality occurs in one detector. Even in this case, the measured value PV can be gently settled to the output of the other detector without sudden change. Therefore, even if the measured value PV is used as the control amount, the control system does not cause a sudden change at this time.

Further, as described above, in the abnormality processing apparatus of the detector redundancy system according to this embodiment, in addition to the conventional range abnormality detection circuits 17 and 18, the abnormality determination section 8 includes the detection difference abnormality detection section 12 and the change. Since the large-rate detection circuits 13 and 14 are provided so that the abnormality can be detected by the logical product of the output of the detection difference abnormality detection unit 12 and the outputs of the large-change-rate detection circuits 13 and 14, the abnormality detection due to deviation from the conventional allowable range is performed. In addition to this, even if the outputs of the two detectors are separated by a certain amount or more, the abnormality of the detectors can be detected. In this example, the number of detectors installed was two, but
The present invention is not limited to this, and the number of detectors may be any number as long as it is plural.

[0039]

As described above in detail, according to the present invention, it is possible to provide an abnormality processing device for a redundant detector system which switches the detector to bumpless when an abnormality occurs in the detector. It is possible to provide an abnormality processing device for a redundant detector system that reliably detects an abnormality even if the abnormality is within the allowable range of the detector output.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an abnormality processing device of a detector redundancy system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an abnormality determination unit in the abnormality processing device of the detector redundancy system according to the exemplary embodiment of the present invention.

FIG. 3 is an abnormality processing block diagram in an abnormality processing device of a conventional detector redundancy system.

FIG. 4 is a block diagram of abnormality determination in an abnormality processing device of a conventional detector redundancy system.

[Explanation of symbols]

2 ... NO1 moving average circuit, 3 ... NO2 moving average circuit, 4
... NO1 switcher, 5 ... NO2 switcher, 6 ... arithmetic averaging circuit, 7 ... change rate limiting circuit, 8 ... abnormality determination section, 12 ... detection difference abnormality detecting section, 13 ... NO1 large change rate detecting circuit, 14 ...
NO2 large change rate detection circuit, 17 ... NO1 range abnormality detection circuit, 18 ... NO2 range abnormality detection circuit.

Claims (3)

[Claims] 1. A measurement value is determined and transmitted based on output values of a plurality of detectors that measure the same measurement target, and
When at least one output value among the output values is determined to be abnormal by the abnormality determination means, the abnormality processing device of the detector redundancy system that excludes the corresponding output value from the target for determining the measurement value, An abnormality processing device for a redundant detector system, comprising change rate limiting means for suppressing an amount of time change of the sent measurement value when the output value in which the abnormality has occurred is removed. 2. The measured value is determined by calculating each time moving average value for each output value and further averaging the calculated time moving averages. Item 1. An abnormality processing device for a redundant detector system according to Item 1. 3. A measurement value is determined and transmitted based on each output value of a plurality of detectors that measure the same measurement object, and
When at least one output value among the output values is determined to be abnormal by the abnormality determination means, the abnormality processing device of the detector redundancy system that excludes the corresponding output value from the target for determining the measurement value, Output difference determination means for determining whether or not the difference between the output values of the detector is equal to or greater than a preset value, and the rate of change of each output value of the detector with respect to time is preset. Output change determination means for determining whether or not the output difference determination means determines whether or not a certain detector has changed more than a preset value, and the output difference determination means. When the difference between the output values is determined to be greater than or equal to the set value, the abnormality of the detector redundancy system characterized by including abnormality determining means for determining that the output value of the detector is abnormal. processing Location.