JPH06180601A - Multiplex controller - Google Patents

Abstract

PURPOSE:To prevent the continuity of the mismatching state of the output of each controller by matching the operating timing of each controller in a multiplex controller. CONSTITUTION:This device is constituted of plural controllers 23 which compare a process signal with a set value, and output a signal B indicating whether or not a condition is established, which are provided corresponding to plural sensors 3 provided at the same points of a plant, and a selecting circuit 9 which outputs a control command S to an equipment 11 to be controlled based on each controller output B. And also, each controller 23 is constituted of a comparator 25 for condition establishment and a comparator 27 for condition failure, discriminating circuit 29 for condition establishment which searches the logical sum of an output signal C of the comparator 25 for condition establishment with the controller output B of its own system, and outputs a discrimination signal E for condition establishment, and collating circuit 31 which fetches the discriminating signal E for condition establishment, an output signal D of the comparator 27 for condition failure, and the discrimination signals E for condition establishment of the other systems, searches the logical product of those signals, and outputs the signal B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a control system for controlling a plant based on a process signal from the plant, wherein process signals at the same point are detected by a plurality of sensors and each detected signal is compared with a set value. The present invention relates to a multiplex control device that establishes internal conditions based on which calculation is performed and outputs an operation command and an operation amount.

[0002]

2. Description of the Related Art In a plant requiring high safety and reliability such as a nuclear power plant, in order to improve the reliability of a plant control system, a sensor for detecting a state quantity of the plant is used to detect the state quantity of the plant. In many cases, even the controller for inputting the processed process amount is multiplexed.

FIG. 4 shows a conventional example of such a multiplexing control apparatus 1, and in FIG. 4, reference numerals 3-1 to 3-n are sensors installed at the same point in the plant. Process signal p1 detected by each sensor 3-1 to 3-n
.About.pn are input to the corresponding controllers 5-1 to 5-n and compared with the given set value r by the comparators 7-1 to 7-n. Based on the comparison result by the comparators 7-1 to 7-n, the controllers 5-1 to 5-n satisfy the condition (ON or 1) when p ≧ r, and do not satisfy the condition (OFF or 0) when p <r. ), Or a signal A1 that satisfies the condition when p≤r and does not satisfy when p> r
~ An is output. The selection circuit 9 inputs the signals A1 to An output from the controllers 5-1 to 5-n and outputs the signals A1 to An.
The operation command S is output to the controlled device 11 when the states An to ON (ON / OFF, 1/0, etc.) match.

[0004]

Generally, the process amount from the sensor individually prepared corresponding to the redundant control device differs depending on the mounting position of the sensor, individual sensor characteristics and the like.

Further, a commonly used comparator has a set value so as not to cause so-called chattering in which the comparison result repeats ON / OFF or 1/0 due to a minute fluctuation of the process amount input from the sensor. Is provided for operating (hereinafter referred to as operating value) and for returning (hereinafter referred to as returning value), and a hysteresis is provided to make a difference between the operating value and the returning value.

When the control device is configured to compare the process amount and the set value by using the comparator having such a hysteresis, each internal condition and the operation result of the redundant control device are normally input. Although some deviation in the operation timing due to the difference in the process amount and variation within the allowable range in the calculation result are allowed, it is ideal that almost the same operation is performed.

However, in the conventional multiplexing control system as shown in FIG. 4, when the process amount p continues between the return value r1 and the operation value r2 as shown in FIG. In some cases, the output signals A1 to An may continue to disagree with each other, and in the case where the operation of the integrator is started or not due to the satisfaction / dissatisfaction of the condition indicated by the output signals A1 to An, each controller may be affected by the continuous disagreement. Therefore, the difference between the allowable values will be generated. The operation command and the operation amount output of the multiplex control device are safety because they are given to the controlled device 11 by 2 out of 3 in which two out of three are matched by the selection circuit 9 or by an intermediate value selection or the like. Although there is no problem above, each controller 5 in the multiplexing control device 1
The control unfavorable state that the operations of -1 to 5-n are not the same continues.

The present invention has been made in order to solve such a conventional problem, and each controller in a multiplex control device is used when it is determined whether or not an internal condition is satisfied by comparing a process amount with a set value. It is an object of the present invention to provide a multiplexing control device in which the internal conditions are satisfied or not satisfied at the same timing to prevent the disagreement state from continuing and each controller performs the same operation.

[0009]

That is, in order to solve the above problems, the multiplexing control device of the present invention, for each process signal detected by a plurality of sensors installed at the same point of the plant, A comparator for condition satisfaction that compares the process signal with the set value for condition satisfaction to determine whether the condition is met, and a process signal is compared with the set value for condition satisfaction that has a significant difference from the set value for condition satisfaction The condition-based comparator that determines whether or not the condition is satisfied, and the output signal of the self-condition-based comparator, the output signal of the self-condition-unvalidated comparator, the self-matching signal, and other condition determination information. It is characterized by having a plurality of controllers provided with a collation signal output unit for outputting a collation signal indicating whether or not it is established, and a selection circuit for outputting a plant operation signal based on output signals from the plurality of controllers. To.

Further, the multiplex control apparatus of the present invention compares the process signal with the set value for condition satisfaction for each process signal detected by a plurality of sensors installed at the same point of the plant and determines whether the condition is satisfied or not. Comparator for condition satisfaction, which makes a judgment of the condition, Comparing the process signal with the setting value for condition satisfaction that has a significant difference from the setting value for condition satisfaction, and judging whether the condition is satisfied or not Determination circuit for outputting a condition satisfaction determination signal composed of the logical sum of the output signal of the self-comparison signal and its own verification signal, and the output signal of the self-condition satisfaction determination circuit and the self-conditional non-compliance comparator Based on the output signals from the plurality of controllers and the matching circuit that outputs the matching signal indicating whether or not the condition is satisfied based on the output signal of And having a selection circuit which outputs an operation signal of the plant.

Furthermore, the multiplexing control device of the present invention compares the process signal with the set value for condition satisfaction for each process signal detected by a plurality of sensors installed at the same point of the plant, and determines whether or not the condition is satisfied. A comparator for satisfying the condition, a process signal that compares the process signal with a set value for the condition not satisfied having a significant difference from the set value for the condition satisfied, and a comparator for not satisfying the condition, A condition determination circuit that outputs a condition determination signal that is a logical product of an output signal of a condition satisfaction comparator and its own verification signal and a logical product of an output signal of its own condition disagreement comparator, and its own condition determination circuit Based on the output signal of the other condition determination circuit and the output signal of the other condition determination circuit, and a controller based on the output signals from the plurality of controllers, each of which has a matching circuit that outputs a verification signal indicating whether or not the condition is satisfied. And having a selection circuit for outputting a preparative operation signal.

[0012]

In the above structure, the condition satisfaction comparator determines whether or not the condition is satisfied depending on whether the process signal input from the corresponding sensor is larger or smaller than the condition satisfaction set value. At the same time, the condition non-compliance comparator determines whether or not the condition is met depending on whether the same process signal is larger or smaller than the condition non-compliance set value. There is a difference between the set value for condition fulfillment and the set value for condition not fulfillment.For example, when the condition is met at the set value or more, the set value used by the condition fulfillment comparator is larger than the set value used by the condition not fulfilled comparator. The value. Each controller considers the output of its own controller and the comparison information of other controllers, in addition to the comparison result by the comparator for condition satisfaction and the comparison result by the comparator for condition not satisfied, and outputs a signal indicating whether or not the condition is satisfied. Is output. This makes it possible to synchronize the operation timings of the satisfaction / non-establishment of conditions among the respective controllers, and avoid repetition of success / failure even when the input process value fluctuates near the set value.

Further, in the configuration provided with the condition satisfaction determination circuit and the collation circuit, the condition satisfaction determination circuit has at least one of the determination result by the condition satisfaction comparator and the immediately previous determination result output from the controller. When the condition is satisfied, a condition satisfaction determination signal indicating that the condition is satisfied is output. The matching circuit inputs the output signal from the condition satisfaction determination circuit, inputs the output signal of the condition failure comparator and the condition satisfaction determination signal from the condition satisfaction determination circuit of the other controller, When all of these input signals satisfy the condition, it is determined that the condition is satisfied, and when any one of them is not satisfied, it is determined that the condition is not satisfied. As a result, the operation timings of the respective controllers coincide with each other, and it is possible to prevent repetition of determination of condition satisfaction / non-establishment due to a value change of the process signal.

Further, in the configuration having the condition judging circuit and the collating circuit, the condition judging circuit is such that at least one of the judgment result by the condition satisfaction comparator and the immediately preceding judgment result output from the controller is satisfied, and When the result of the judgment by the comparator for not satisfying the condition is that the condition is satisfied, the condition judging signal that makes the condition satisfied is output. Then, the matching circuit inputs the output signal from the condition judging circuit and the same condition judging signal from the condition judging circuits of the other controllers, and a predetermined number of input signals among these input signals are input. When the condition is satisfied, it is determined that the condition is satisfied. This makes it possible to synchronize the operation timings of the conditions established / not established among the respective controllers, and it is possible to prevent repeated determinations of the conditions established / not established due to the change in the value of the process signal.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. Note that the same portions are denoted by the same reference symbols throughout the drawings, and overlapping description will be omitted.

FIG. 1 shows an embodiment of the multiplexing controller of the present invention. Here, the number of sensors 3 installed at the same point will be described as three. The multiplex control device 21 has controllers 23-1 to 23 to which the process signals p1 to p3 are input from the sensors 3-1 to 3-3, respectively.
-3 and output signals B from these controllers 23-1 to 23-3
The selection circuit 9 outputs the operation command S to the controlled device 11 based on 1 to B3.

In each of the controllers 23-1 to 23-3, comparators that do not have hysteresis between the operating value and the return value are provided for satisfying the conditions 25-1 to 25-3 and not satisfying the conditions 27-1. ~ 27-3
And are separately provided. Conditional comparator 25-1 ~
25-3 is the process signals p1 to p input from the plant.
3 is compared with the set value r2 for satisfying the condition corresponding to the operation value,
For example, if p ≧ r2, the condition is satisfied (ON), and if p <r2, the condition is not satisfied (OFF), and the determination results C1 to C3 are output. The condition unsatisfied comparators 27-1 to 27-3 compare the process signals p1 to p3 input from the plant with the condition unsatisfied set value r1 corresponding to the return value, and the condition satisfied comparators 25-1 to 25- As in the case of 3, if p≥r1 is satisfied, the condition is satisfied (ON), and if p <r1 is satisfied, the condition is not satisfied (OFF), and the determination results D1 to D3 are output. In this case, r1 <r
It is 2.

Each of the controllers 23-1 to 23-3 further includes a determination circuit 29-1 to 29-3 for condition satisfaction and a matching circuit 31-1 to 3-3.
1-3 are provided. Conditional determination circuit 29-1 to 29-2
Reference numeral 9-3 is an OR circuit, and comparators 25-1 to 25-2 for satisfying the condition.
The output signals C1 to C3 from 5-3 are input, and the output signals B1 'to B3' from the previous control signals 23-1 to 23-3 of the own system are input.
B3 'is taken in, and condition-satisfying determination signals E1 to E3 consisting of the logical sum of the signals C1 to C3 and the signals B1' to B3 'are output. The matching circuits 31-1 to 31-3 are AND circuits, and the condition satisfaction determination signals E1 to E3 from the condition satisfaction determination circuits 29-1 to 29-3 and the condition failure comparators 27-1 to 27-3. From the output signals D1 to D3 from the output signal of the determination circuit for satisfaction of the condition of the other system (in the case of the matching circuit 31-1,
The signals E2 and E3 from the circuits 29-2 and 29-3 are taken in and each input signal (D1, E1, in the case of the matching circuit 31-1)
The signals B1 to B3 formed by the logical product of E2 and E3) are output to the selection circuit 9 as controller output signals.

Next, the operation of the multiplexing control device 21 having the above configuration will be described. Here, a case where the condition is satisfied (= 1) when the process value is equal to or larger than the set value and the condition is not satisfied (= 0) when the process value is smaller than the set value will be described as an example.

When the output signals E1 to E3 of the condition satisfaction determination circuits 29-1 to 29-3 are expressed by logical expressions,

## EQU1 ## E1 = C1 + B1 'E2 = C2 + B2' E3 = C3 + B3 '. Further, when the output signals B1 to B3 of the matching circuits 31-1 to 31-3, that is, the controllers 23-1 to 23-3 are expressed by logical expressions,

[Equation 2] B1 = E1 * E2 * E3 * D1 B2 = E1 * E2 * E3 * D2 B3 = E1 * E2 * E3 * D3.

Here, when the process signals p1 to p3 which are the detection values of the respective sensors 3-1 to 3-3 are all equal to or more than the set value r2 for satisfying the condition, the comparators 25-1 to 25-3 for satisfying the condition. The output signals C1 to C3 are

[Equation 3] Since C1 = C2 = C3 = 1, from (Equation 1), the immediately preceding controller outputs B1 ′ to B are obtained.
Regardless of the 3'state, the judgment signals E1 to E3 for satisfaction of the condition are established.
Is

## EQU4 ## E1 = E2 = E3 = 1. Further, in this case, the comparators 27-1 to 27-2 for not satisfying the condition
The output signals D1 to D3 of 7-3 are naturally

## EQU5 ## Since D1 = D2 = D3 = 1, from (Equation 2) and (Equation 4), each controller 23-1
Outputs B1 to B3 of ~ 23-3 are all

## EQU6 ## B1 = B2 = B3 = 1 (established).

If any one of the process signals p1 to p3 is less than the set value r1 for unsatisfied condition, one of the output signals D1 to D3 of the comparators 27-1 to 27-3 for unsatisfied condition is 0. Therefore, according to (Equation 2) and (Equation 1), one of the output signals E1 to E3 of the determination circuit 29-1 to 29-3 for condition satisfaction becomes 0, and therefore from (Equation 2) the controller output B1 to B3 is all

## EQU7 ## B1 = B2 = B3 = 0 (not established).

Furthermore, when the process signals p1 to p3 are equal to or more than the set value r1 for not satisfying the condition and less than the set value r2 for satisfying the condition, the comparators for condition satisfaction 25-1 to 25-3 and the comparator for condition not satisfied 27- Output signals C1 to C of 1 to 27-3
3, D1 to D3 are

[Equation 8] C1 = C2 = C3 = 0 D1 = D2 = D3 = 1, but the output signals E1 to E3 of the condition determination determination circuits 29-1 to 29-3 are as shown in (Equation 1). , B3 'depending on the immediately preceding controller outputs B1' to B3 '. That is, if B1 'to B3' are 0, E1 to E3 are 0, and according to (Equation 2), the matching circuit 3
The output signals B1 to B3 of 1-1 to 31-3 are zero. on the other hand,
If B1 'to B3' is 1, E1 to E3 will be 1 (Equation 2)
Accordingly, the output signals B1 to B3 of the matching circuits 31-1 to 31-3 become 1. Therefore, when the process signals p1 to p3 are equal to or greater than the condition satisfaction setting value r1 and less than the condition satisfaction setting value r2, the previous control state is maintained and the controller outputs B1 to B3.
3 does not change.

As is clear from the above description, according to the above embodiment, when the process values p1 to p3 from the plant become large in the direction of approaching the condition-satisfying set value r2, Only when the conditions of the signals C1 to C3 are satisfied, the controller outputs B1 to B3 are satisfied at the same timing, and conversely, one of the process values becomes less than the condition non-establishment setting value r1 from the condition of this condition being satisfied. When it decreases, the controller outputs B1 to B3 are all immediately disabled at the same time. In this way, the internal conditions B1 to B3 output by the respective controllers are satisfied / not satisfied at the same timing and always match. If the process values p1 to p3 are equal to or more than the set value r1 for not satisfying the condition and less than the set value r2 for satisfying the condition, the states of the output signals B1 to B3 of the respective controllers do not change and are satisfied by the change of the process value. / It does not cause repeated failure.

FIG. 2 shows another embodiment of the present invention, which is different from the embodiment shown in FIG. 1 in that instead of the condition satisfaction judging circuits 29-1 to 29-3, the condition judging circuit 41- 1 to 41
-3 is provided, and the matching circuits 43-1 to 43-3 are not OR circuits but OR circuits. Condition determination circuits 41-1 to 4
1-3 are output signals C of the comparators 25-1 to 25-3 for condition satisfaction.
Signals E1 to E3 which are the logical sum of 1 to C3 and the controller output signals B1 'to B3' immediately before the own system and the comparator 27 for not satisfying the condition.
-1 to 27-3 and the logical product of the output signals D1 to D3 are output as the condition determination signals F1 to F3. Collation circuit 43-1 to 43
-3 is all condition judgment signals F1, F2, F of own system and other system
3 is input and the logical sum thereof is output as controller outputs B1 to B3.

In this configuration, the condition judging circuit 41-1
When the condition judgment signals F1 to F3 from ~ 41-3 are expressed by a logical expression,

[Equation 9] F1 = D1.E1 F2 = D2.E2 F3 = D3.E3 and the controller outputs B1 to B3 are

## EQU10 ## B1 = F1 + F2 + F3 B2 = F1 + F2 + F3 B3 = F1 + F2 + F3 In this way, the controller outputs B1 to B3 are all equal, so that the controllers operate at the same timing. In this embodiment, when any one of the process values p1 to p3 is equal to or more than the condition setting set value r2, one of the condition determination signals F1 to F3 becomes 1 from (Equation 1) and (Equation 9). , (Equation 10), all the controller outputs B1 to B3 are 1 (condition is satisfied). Also, the process values p1 to p
When all of 3 become less than the set value r1 for not satisfying the condition, the condition determination signals F1 to F3 all become 0 from (Equation 9), and the controller outputs B1 to B3 all become 0 from (Equation 10).
(The condition is not satisfied). Furthermore, the process signals p1 to p
When 3 is decreased from the condition-satisfying set value r2 to less than the condition-satisfaction setting value r2, the output signals C1 to
C3 changes from 1 to 0, but the previous controller output B1 '~
Since B3 'is 1, the signals E1 to E3 are 1 from (Equation 1).
As is clear from (Equation 9), the controller outputs B1 to B3 are 1 unless all the output signals D1 to D3 of the condition non-satisfying comparators 27-1 to 27-3 change to 0. It remains unchanged. Further, when the process signals p1 to p3 increase from less than the set value r1 for not satisfying the condition to more than, the output signals D1 to D3 of the comparators 27-1 to 27-3 for not satisfying the condition change from 0 to 1, but If the signals p1 to p3 are less than the condition setting set value r2, the condition satisfaction comparator 25-1
The output signals C1 to C3 of ~ 25-3 do not change from 0 to 1,
According to (Equation 1), the signals E1 to E3 also remain 0. Therefore, the signals F1 to F3, which are the logical product of the signals D1 to D3 and the signals E1 to E3, remain unchanged at 0 and the process signal p1
The controller outputs B1 to B3 remain 0 unless any of .about.p3 exceeds the setting value r2 for condition satisfaction.

As described above, in this embodiment, when any one of the process values p1 to p3 becomes equal to or more than the set value r2 for satisfying the condition, the controller outputs B1 to B3 satisfy the condition at the same timing and the process value When all of p1 to p3 become less than the set value r1 for not satisfying the condition, the controller outputs B1 to B3 are not satisfied at the same timing.

FIG. 3 shows still another embodiment of the present invention. The OR logic matching circuit 43-1 of the embodiment shown in FIG.
.. 43-3 are replaced by 2 out of 3 logic collating circuits 51-1 to 51-3.

In the matching circuits 51-1 to 51-3,
The output signals B1 to B3 are

[Equation 11] B1 = F1.multidot.F2 + F2.multidot.F3 + F3.multidot.F1 = B2 = B3, and each controller operates at the same timing. Also,
In this embodiment, when the process signals of the two systems are equal to or more than the set value r2 for satisfying the condition or less than the set value r1 for not satisfying the condition, the controller outputs B1 to B3 are satisfied or not satisfied.

In addition to the above-mentioned embodiment, based on the judgment result by the two comparators having different set values, the output of the controller of the own system, and the judgment information of the controller of the other system, the controller among the controllers is determined. Each controller can be configured to synchronize the operation timing. The present invention also includes a multiplex control device including such a controller.

[0031]

As described above, according to the present invention,
Even when only the process value of the single system changes and the comparator of the controller of the single system operates, the output signal of each controller always satisfies / is not satisfied at the same timing. It is possible to match the internal conditions between the controllers.

In particular, when performing control such as starting the integration operation according to internal conditions, the integration operation start timing can be adjusted so that there is no difference in the internal calculation result beyond the allowable value and stable control is achieved. It is possible to obtain a highly reliable multiplexing control device which operates.

[Brief description of drawings]

FIG. 1 is a block diagram showing a multiplexing controller according to an embodiment of the present invention.

FIG. 2 is a circuit showing a main part of a multiplexing controller according to another embodiment of the present invention.

FIG. 3 is a circuit showing a main part of a multiplexing controller according to still another embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional example of a multiplexing control device.

FIG. 5 is a diagram illustrating an operation of a comparator having an operation value having a hysteresis in a set value and a return value.

[Explanation of symbols]

 3 ... Sensor 9 ... Selection circuit 11 ... Controlled device 21 ... Multiplexing control device 23 ... Controller 25 ... Comparator for condition satisfaction 27 ... Comparator for condition failure 29 .... Confirmation circuit for condition establishment 31 ..... Collation circuit 41 .... Condition determination circuit 43 ..... Collation circuit 51 .... Collation circuit

Claims (3)

[Claims] 1. For each of the process signals detected by a plurality of sensors installed at the same point in the plant, the process signal is compared with a set value for satisfying the condition to determine whether the condition is satisfied or not. A comparator, a comparator for condition not fulfilling which judges whether or not the condition is satisfied by comparing the process signal with a set value for condition not fulfilling which is significantly different from the set value for fulfilling the condition, and a comparator for fulfilling its own condition. A plurality of controllers having a collation signal output section for outputting a collation signal indicating whether or not the condition is satisfied based on the output signal, the output signal of the self-condition non-conforming comparator, the self collation signal, and other condition judgment information; And a selection circuit that outputs an operation signal of the plant based on output signals from the plurality of controllers. 2. For the satisfaction of a condition, for each process signal detected by a plurality of sensors installed at the same point of the plant, the process signal is compared with a set value for satisfaction of the condition to determine whether or not the condition is satisfied. Comparator, Comparing the process signal with the setting value for not satisfying the condition having a significant difference from the setting value for satisfying the condition to determine whether or not the condition is satisfied, output of the comparator for satisfying condition Signal for determining whether the condition is satisfied, which is a logical sum of the signal and its own collation signal, and the output signal of the determination circuit for determining whether the condition is satisfied and the output signal of the comparator for not satisfying the condition Based on the output signal of the determination circuit for condition satisfaction, a plurality of controllers including a verification circuit that outputs a verification signal indicating whether or not the conditions are satisfied, and the controller based on output signals from the plurality of controllers. Multiplexing control apparatus characterized by having a selection circuit for outputting a preparative operation signal. 3. For the satisfaction of a condition, for each process signal detected by a plurality of sensors installed at the same point of the plant, the process signal is compared with a set value for satisfaction of the condition to determine whether or not the condition is satisfied. Comparator, Comparing the process signal with the setting value for not satisfying the condition having a significant difference from the setting value for satisfying the condition to determine whether or not the condition is satisfied, output of the comparator for satisfying condition Condition judgment circuit that outputs a condition judgment signal that is a logical product of the logical sum of the signal and its own collation signal and the output signal of the own condition non-satisfaction comparator, and the output signal of the own condition judgment circuit and other conditions Based on the output signal of the determination circuit, a plurality of controllers including a matching circuit that outputs a matching signal indicating whether or not the condition is satisfied, based on the output signals from the plurality of controllers, the operation signal of the plant Multiplexing control apparatus characterized by having a selection circuit for force.