JPH01276206A - Monitoring device for sequence program control system - Google Patents

Abstract

PURPOSE:To prevent a misdiagnosis due to the realization sequence non- specification of AND conditions by comparing a real operation pattern with a storage pattern in each step to advance from a non-coincidence step at the time of obtaining the non-coincidence pattern and continuing a monitoring in making the coincidence step into the monitoring step of a normal pattern storing part when the patterns coincide. CONSTITUTION:First, an operation facility 1 is operated, the real operation patterns of respective control elements are successively monitored, and at the time of the pattern non-coincidence, whether the storage pattern to coincide with each step to advance before the non-coincidence step exists or not is checked. When the storage pattern to coincide exists, the monitoring of the operation pattern is continued from the step in making the step to have the storage pattern into the monitoring step to which the operation pattern at a present time in a normal pattern storing part 17 corresponds. Thus, an abnormality alarm to accompany the action stop of the facility is not generated, and the monitoring of a control condition can be continued.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a monitor device for a sequence program control system.

(Prior Art) Sequence program control is already known, in which a sequence program is created that specifies the operation sequence of a predetermined control equipment to be controlled, and the operation of each stage of the control is sequentially advanced according to this sequence program. ,
For example, in assembly lines of various mechanical devices and machine tools,
It is often used to automatically and continuously perform the next stage of action in response to the previous stage of action.

By the way, in this sequence program control, when time monitoring, that is, no-kense monitoring, is performed to see whether the control is being performed normally, the above sequence program that controls the operation of the control equipment is further provided with a function for this monitoring. Some devices are configured to incorporate a separate program and issue a warning in the event of an abnormality. However, in such a configuration, it is necessary to change both the operation control and monitoring programs of the equipment each time the equipment is changed. Since this is necessary, there is a drawback that the overall program capacity becomes large.

Therefore, recently, playback type no-kense monitor devices, which do not have the above-mentioned drawbacks, have come into widespread use. This device sequentially stores in a predetermined memory the operation patterns of each component of the Noken control circuit when the equipment is operated normally, and
This system sequentially checks whether the operating pattern during actual operation of the equipment matches the pre-stored standard operating pattern, and issues an abnormality alarm when they do not match. . Regarding this, for example, JP-A-60
Publication No. 238906 states that in the playback type no-kense monitor device, when the above-mentioned operation pattern mismatch occurs continuously, it is determined to be an abnormality, and the operation patterns before and after the occurrence of the abnormality are stored and the cause of the abnormality is determined. The technical idea is to make the explanation easier.

By the way, in the playback type sequence monitor device as described above, when a mismatch pattern is obtained, in principle, it is determined that the mismatched control element among them is abnormal, but usually the true abnormal element is determined to be abnormal. are originally some of them (in most cases, only one), and others are often determined to be abnormal as a result of the occurrence of a true abnormal element, which causes a chain reaction. .

In other words, in the case of the playback type sequence monitor device described above, each time there is a predetermined transition (I10 change) in the operation pattern on the equipment side, the step on the memory pattern side that serves as the reference is advanced and compared, so an abnormal element occurs. In this case, this itself eventually causes a transition of the operation pattern and the step of the memory pattern moves forward, and the result of comparing the control element that should have changed with the memory pattern of this advanced step is that it has not changed. may be determined to be abnormal. Therefore, when an abnormality is pointed out in a plurality of control elements in the playback type sequence monitor device as described above, it becomes necessary to further check whether or not there is a true abnormality in all of them. However, this cannot be put to practical use at all.

Therefore, as a means to solve the above-mentioned problems, for example, an operating state change detection unit that detects changes in the operating state of each control system element constituting the above sequence program control system, and a normal pattern storage section that stores the operating pattern of each control element for each step in which the pattern changes; an actual operating pattern obtained by detection by the operating state change detection section; and a stored operating pattern in the normal pattern storage section. A playback sequence monitor is constructed by comprising an operation pattern comparison section that compares the operation patterns, and a control state diagnosis processing section that diagnoses the control state deafness. a match determining unit that determines whether or not the stored pattern matches the above-mentioned stored pattern; and upon receiving a non-matching determination from the matching determining unit, the unmatched control element is compared with that of the stored pattern of the previous step of the corresponding step. and a priority abnormality determination unit that preferentially determines as an abnormality a mismatched element that has changed even though it should not have changed in the corresponding step by comparing it with that of the previous step. is possible.

In a playback sequence monitor device having such a configuration, when an inconsistency element is first pointed out from the comparison of the above-mentioned operation patterns, a comparison with the memory pattern of the surface step determines that the inconsistency element has changed even though it should have changed. Elements that are inconsistent because they have not changed, or elements that are inconsistent because they have changed when they should not have been changed are checked, that is, back-checked. In the former case, the inconsistency element that has not actually changed does not cause a transition in the operating pattern, so in the latter case, the inconsistency element that has actually changed has occurred, resulting in a chain reaction of inconsistency. Therefore, it turns out that the latter inconsistent element is the true abnormal element.

Therefore, with such a configuration, when a discrepancy is pointed out by comparing the above-mentioned operation patterns, it is further compared with the memory pattern of the previous step, and even though it should not change, it changes and becomes a discrepancy. Since the element is detected, even if multiple mismatching elements are obtained as mentioned above, the true abnormal element can be found relatively easily, and the diagnostic accuracy of the sequence monitor device can be improved. It turns out.

(Problems to be Solved by the Invention) Incidentally, the above-mentioned sequence program operating equipment is generally configured with a self-holding circuit, as shown in the system shown in FIG. 4, for example. Fourth
In the case of the system shown in the figure, one main automatic lift-up station section 100 and the automated built-up station section 100 are transferred via a conveyor system 200 to a subassembly station 30 by manual operation.
When the work at the automated build-up station section +00 is completed, the conveyor system 200 is started and the workpiece 500 is transferred to the subassembly station 300, and the workpiece 500 is transferred to the subassembly station 300. Station 300 is now operational. In the above case, the conveyor 2
00 is activated by first turning on the assembly work completion I10 signal at the automated build-up station and the turning on of the sub-Alan-complete button (having a self-holding circuit) 400 due to the completion of the previous work at the sub-assembly station 300. 2
This can be done by establishing the logical product of two conditions.

However, among the logical product conditions, it is not known which of the tasks at the automated build-up station section 100 and the subassembly station 300 will be completed first. Therefore, two sets of combination states (I10 pattern) always occur as follows.

[1] When the work at the automated build-up station section 100 is completed first (*The conveyor 200 is started at the same time as the subassembly completion button 400 is pressed.) [2] When the work is completed first at the subassembly station (*The subassembly completion button 400 is self-held, and the conveyor 200 is activated by the work completion I10 output of the automated build-up station.) In this way, if some of the system control elements have a self-holding circuit,
In the end, the transition pattern of the I10 output becomes more diverse, and with the playback sequence monitor as described above, it becomes impossible to make accurate abnormality judgments (for example, in the above example, the step ( (b), no matching pattern can be found after the comparison judgment in step (d)).

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above problems, and each step of the control operation is performed by a sequence program that specifies the order of control operations for predetermined operating equipment. In a sequence program control system that proceeds sequentially according to instructions, changes in the operating state of various control elements constituting the sequence program control system and changes in the operating state of the self-holding internal relay of each control element are detected respectively. an operating state change detection section; a normal pattern storage section that stores an operating pattern representing a change in the operating state of the various control elements during normal operation of the operating equipment for each step in which the operating pattern changes; , an operation pattern comparison section that compares the actual operation patterns of the various control elements detected by the operation state change detection section and the normal pattern storage section of the relevant step stored in the normal pattern storage section of those control elements; and an abnormality diagnosis processing section for diagnosing an abnormality in the control state by monitoring whether or not there is a mismatch between the normal stored pattern and the actual operation pattern through comparison in the operation pattern comparison section.

(Function) In the configuration of the present invention described above, the operating equipment is first operated to sequentially monitor the actual operating pattern of each control element, and when the patterns do not match, each step advanced before the mismatched step is matched. Check to see if there is a memory pattern. If there is a matching stored pattern, the step with that stored pattern is treated as the monitoring step to which the current operating pattern in the normal pattern storage section corresponds, and monitoring of the operating pattern is continued from that step.

In other words, in this case, in the memory in the normal pattern storage unit, the operating states of multiple elements change sequentially, for example, by repeatedly turning on and off, whereas in reality, multiple elements change at the same time or in different orders. There was a memory pattern that changed and matched the forward step. Therefore, if we consider the logical product (A N D) condition, the order in which it is established is simply different from the one in memory, and this is an operation pattern that poses no problem for the equipment. It is possible to continue monitoring the control state without issuing a warning.

Further, if there is no stored pattern whose operation pattern matches each of the steps advanced above, the next operation pattern transition is made without changing the monitoring step in the normal pattern storage section. If there is this transition, when looking at the establishment of the logical product condition, it is simply assumed that the order of establishment is different from what was remembered, the state of the equipment has changed, and there is no problem at the moment, ・Similar to the previous case It is possible to see whether the pattern matches the memory pattern of the corresponding monitoring step or its forward step.

Note that if there is no such transition, the cause of the abnormality can be diagnosed from the control element that caused the initial mismatch in the operation patterns as an abnormality, or the control element that caused the mismatch in the subsequent forward step.

(Effects of the Invention) Therefore, according to the above configuration of the present invention, when a mismatch pattern is obtained in the playback type no-kense monitor device as described above, the actual operation pattern is The step is compared with the stored pattern, and if the pattern matches, the matching step is considered as a monitoring step in the normal pattern storage unit and monitoring is continued, so when the control progresses due to the establishment of the logical product condition, the monitoring device's In addition to being able to prevent erroneous diagnoses due to the order in which the above logical product conditions are met without reducing diagnostic accuracy, the self-holding circuit also prevents malfunctions like conventional ones even when the transitions of mismatched patterns become diverse. It is possible to improve the reliability.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the overall configuration of a monitor device in the sequence program control system of the same embodiment.

In the figure, reference numeral l indicates a predetermined operating equipment whose operation should be controlled seamlessly, and the control system of this equipment I includes a frequency detection element (for example, a limit switch) for detecting the state of the equipment l, and a plurality of and an output element (for example, a Norinda device) that operates when all of the detection elements are in a specific operating state, that is, when an AND condition is established.

FIG. 2 shows an example of the equipment 1 (boring machine). In this example, a working head 3 with a drill 2 is raised and lowered by means of a rolling device 4 as an output element. This cylinder device 4 detects the positioning of the workpiece IO by the first limit switch (LSI) 6 which detects the absence of a worker on the safety mat 5 and the positioning cylinder device 8°9 on the table 7. The second and third limit switches (L S 2) I I ,
When both (LS3) and 12 are on, the working head 3 is lowered to perform the drilling operation.

By the way, in the sequence monitor device shown in FIG. 1, reference numeral 15 is a 10-state manual input section into which a human output signal (INloUT) representing the operating state of each of the control elements is input, and 16 is an I10 state input section I5. I7 is a normal pattern storage unit, which is an operation change detection unit that detects a change in each of the above 110 states, that is, a transition in the operation pattern of all elements, based on the output.

This normal pattern storage unit 17 causes the above-mentioned equipment l to perform a normal operation in advance, and stores a reference pattern for each step in which the operation pattern changes (the I10 state of at least one element changes). This is what I remembered as.

Further, reference numeral 18 indicates the actual operation pattern obtained by the operation change detection section 16 and the normal pattern storage section 17.
The reference memory pattern to be compared is extracted by the comparison target extraction unit 20 based on a command from the comparison execution control unit, and the comparison result is subjected to abnormal state diagnosis processing. The presence or absence of mismatch between the actual operating pattern and the correct memory pattern serving as the reference is monitored, and the diagnosis result is provided to the diagnosis result output section 22 and the comparison execution control section 19.

The comparison execution control section 19 is configured to have the following functions.

(1) First, the operation change detection section 16 detects the above
Each time a change in the 0 state is detected and the above-mentioned control step shifts, the comparison target extraction unit 20 is caused to extract the memory pattern of the corresponding monitoring step in the normal pattern storage unit 17, and a comparison execution command is issued to the comparison unit 18. give.

(2) Next, when the diagnostic processing unit 21 detects a discrepancy in the operation patterns, the comparison target extraction unit 20 receives the storage pattern of the next step of the monitoring step in which the discrepancy occurred from the normal pattern storage unit 17. Give a command to extract. If the patterns do not match even in this advanced step, a command to move forward up to a predetermined step is sequentially given each time there is a mismatch, and the presence or absence of pattern matching is checked in the forward state. Then, check this progress (hereinafter,
When a pattern match is obtained as a result of the back check (this is referred to as a forward check), the matched step is set as the monitoring step to which the operation pattern in the normal pattern storage section 17 corresponds, and from that step the above ( The function 1) allows continuous monitoring of the operating pattern.

Furthermore, in the case of this embodiment, in order to stop the forward check, is there any I10 change (manpower/output deterioration) of the output element in the reference memory pattern given from the comparison target extraction section 20 to the comparison section 18? In other words, it is extracted whether or not the operation pattern obtained by the output change step extraction section 23 and the operation change detection section 16 has the same output change. A change content extraction unit 24 is provided.

That is, when the pattern extracted from the normal pattern storage section 17 is a step with a change in output, the change step extraction section 23 controls the comparison execution control section I9.
A forward check abort command is given to the forward check to abort the above forward check. As a result, when the patterns do not match, the comparison execution control unit 19 causes the comparison target extraction unit 20 to return the previously advanced step to the original monitoring step, synchronize it, and then perform subsequent extraction work.

On the other hand, if there is a transition in the operation pattern after the monitoring step is restored as described above, the change content extraction unit 24 extracts the I10 change content in that transition and provides it to one comparison execution control unit. As a result, the comparison execution control unit 19
When the change in I10 is due to the output element of the output change step in which the forward check was stopped, a control command is given to the comparison target extraction unit 20 to extract the output change step as a monitoring step, and from now on, this output change The extraction work is performed sequentially from the next step.

Furthermore, if the operation pattern does not match when the output change step is extracted as a monitoring step, the diagnostic processing unit 21 points out the element of the mismatch, and if a forward check is being performed, the check is performed. The diagnostic result output unit 2 also points out the factors that caused the discrepancy.
2, and if there is a transition in the operation pattern again after that, the above indication is cleared (released).

Therefore, the control operation flow of the monitor device is as shown in the flowchart of FIG. 3, for example.

First, monitoring is started by a start signal, and the presence or absence of a change in the I10 state is determined in the operation change detection section 16.
If the result is YES that there is a predetermined change, the judgment result of the previous mismatch I10 is cleared, and then the number of the monitoring step is advanced by one (counted up) by a count-up operation, and further extracted from the normal pattern storage section 17. The pattern changes to either the memory pattern that serves as the reference for the next start signal or the next start signal. (Steps 81 to S3). Then, by comparing the actual operating pattern and the extracted memory pattern,
If the operation patterns match, the monitoring step advances sequentially according to the change (transition) of the I10 state by the above-mentioned Sl, S2°S, and if the above-mentioned patterns do not match, the monitoring step at that time advances the output change ( I10 change of output element)
It is determined whether or not (step S,
S.).

If it is a monitoring step with no output change (NO), the step number is sequentially advanced for forward check, and each time the current operating pattern is compared with the memory pattern of each advanced step (step S Il+
S7). If there is a pattern match by this forward check up to a monitoring step with an output change, the matching step is regarded as the monitoring step to which the current operation pattern corresponds, and monitoring from that step onwards is continued (S7 -Return to 9l).

If there is no pattern match in the forward check, the element of mismatch 110 in the monitoring step with the output change is pointed out, the forward check advances the monitoring step back to its original state, and the forward check in the original monitoring step is repeated. Point out the element of the discrepancy I10 that caused it (step S).

Next, proceeding to step S, the step number counted up in the forward check described above is returned to the original step number. Also, after that step S. The discrepancy I10 that caused the above forward check will be pointed out as a reference.

Furthermore, it is determined whether the I10 state that changed in step S11 is the output of the control element targeted in the previous step S5, and if YES, the process proceeds to step S+t where the output change has occurred. While counting up the step number up to the step number, if NO, step S
Proceed to +2 and count down the same step number.

Next, a specific example of the above-mentioned monitoring operation in the equipment shown in FIG. 2 mentioned above will be explained.

<Example 1> When the transition of the memory pattern stored in the normal pattern storage unit 17 is as shown in Table 1 below, the actual transition of the operation pattern is as shown in Table 2.

(Table 1) (Table 2) First, step (a) matches monitoring step (1).

Then, when moving to step (b), the monitoring step is (
2).

(b) and (2) above are inconsistent. This (2) is the output change (
Since this is a step in which there is no operation of the cylinder device, the step moves forward l steps for forward check, and (b) and (3)
).

(b) and (3) above are inconsistent. Since this step (3) is also a step in which the output does not change, move forward one step and compare (b) and (4).

(B) and (4) above are inconsistent. This (4) is an output change step, which points out the element (LSI, cylinder device) with the mismatch I10, and since the changed Ilo is not the output targeted for the forward check, the forward check is stopped and the monitoring step moves forward. Return to the original (2). Point out the elements (LSI to LS3) of mismatch I10 for reference.

Next, when there is a transition to step (c) (change to state I10), the above-mentioned indication of inconsistency is cleared.

In the transition to (c) above, the elements (10) that have changed are the LSI and the cylinder device, and this cylinder device is in the output change step (where the forward check is canceled) (
This is the output element of 4). Therefore, we can change the monitoring step to this (
Advance to 4) and compare (c) and (4).

(c) and (4) above are consistent.

Therefore, in the actual transition of the operation pattern, the order in which the AND conditions were established was simply different from the one in memory, and there was no problem with the operation of the equipment, and there was no misdiagnosis (alarm) that would have caused the stoppage. do not have.

Also, as mentioned above, when the element of Ilo that has changed in the transition to (c) is the output element of the output change step in which the forward check was stopped, the monitoring step is forced to match this output change step. Since the,
Each step of the actuation pattern to be compared and the stored pattern are matched with each other using this output element as a reference, and misalignment in matching is prevented.

In addition, in the case of the transition to the above (c), patterns can be compared starting from the undone monitoring step (2). In this case, (c) and (2) do not match, (c) and (3) by forward check also do not match, and the next (c) and (
4) is a match, so the monitoring step is set to (4).

<Example 2> When the memory pattern transition is Table 3 and the actual operation pattern transition is Table 4.

(Table 3) (Table 4) (a) is (1
) matches.

(l near) is inconsistent with (2). (2) is an output change step. Pointed out the element of mismatch I10 (LS2.LS3.Cylinder device).

By moving to step (c), the above disagreement was cleared. (c) is inconsistent with (2). This discrepancy pointed out element 10 (L S 3, cylinder device).

By moving to step (d), the above disagreement was cleared. (d) is consistent with (2).

Therefore, in the memory pattern, the AND conditions are satisfied at the same time, but in the actual operation pattern, the AND conditions are simply satisfied one after another, and there is no problem with the operation of the equipment, but it may cause the equipment to stop. There is no misdiagnosis (W report).

<Example 3> When the memory pattern transition is Table 5 and the actual operation pattern transition is Table 6.

(Table 5) (Table 6) (A) is (+
) matches.

(b) is inconsistent with (2). (2) is not an output change step, so the forward check is (b) and (3) is not an output change step, so the forward check is (b).
Compare and (4). This (b) and (4) are also inconsistent.

Since this (4) is an output change step, the mismatch I1
Point out the element 0 (LSI, L, S3. cylinder device). Then, the monitoring step is returned by the amount of progress made in the forward check, and the reference mismatch I10 element (LSI, L
Point out S2). Next, move to step (c) to clear the above disagreement.

Comparing (c) and (2) above, they do not match, so a forward check is performed in the same way as in (b) above. In other words, comparing (c) and (3), they do not match and (3) is not an output change step, so (c) and (4)
). This (c) and (4) are inconsistent, and (
4) is an output change step, so point out the element (LSI, cylinder device) with the mismatch I10, return the monitoring step to the original (2), and change the reference element with the mismatch I10 (LSI-
LS3). Then, since there is no change in the next I10 state and the equipment is stopped, an alarm will be issued.

Therefore, in this case, the reference discrepancy I1 is the diagnostic result.
0 elements LSI to LS3 are pointed out, but there is a mismatch in the output change step I10 element LS2. Since LS3 is not included, this LS2. It can be seen that LS3 is working. Regarding the LSI, it was pointed out that there was a discrepancy in the reference above, and it was also pointed out that there was a discrepancy in the output change step, and it was also pointed out that the cylinder device did not operate. All that is required is to inspect this LSI and the positioning cylinder device 8 for its operation.

In principle, the number of steps to perform forward check may be the number of AND conditions written in the sequence program (maximum number - 1), but as in the above example, if the output change is not observed from the forward check start step, It may also be used as a check up to the next step. In other words, if there is an output change due to the establishment of an AND condition, and if there are steps in which some of the AND conditions are already satisfied before the forward check start step, there is no need to perform an extra forward check, which can prevent the monitor from running out of control. In addition to preventing this, it is also possible to cope with cases where some AND conditions are satisfied and disappear repeatedly.

In the configuration of the embodiment of the present invention described above, first, the operating equipment is operated and the actual operating pattern of each control element is sequentially monitored, and when the patterns do not match, a record is made that matches each step advanced before the mismatched step. Check if there is a pattern.

If there is a matching stored pattern, the step with that stored pattern is treated as the monitoring step to which the current operating pattern in the normal pattern storage section corresponds, and monitoring of the operating pattern is continued from that step.

In other words, in this case, normal pattern 8i! In memory, the operating states of multiple elements change sequentially, for example by turning on and off, whereas in reality, multiple elements change at the same time or change in a different order to match the forward step. There must have been a memory pattern. Therefore, A
Considering the ND condition, the order in which it is established is simply different from the one in memory, but it is an operation pattern that poses no problem for the equipment, so the control state can be changed without issuing an abnormal alarm that would cause the equipment to stop operating. can continue to be monitored.

Further, if there is no stored pattern whose operation pattern matches each of the steps advanced above, the next operation pattern transition is waited for without changing the monitoring step in the normal pattern storage section. If this transition exists, A
When looking at the establishment of the ND condition, it is simply a different order of establishment than what was remembered, and the state of the equipment has changed and there is no problem at the moment, so the corresponding monitoring step or its progress is performed in the same way as in the previous case. You can see whether the step matches or does not match the memorized pattern.

Note that if the above transition does not occur, the cause of the abnormality can be diagnosed from the element that caused the initial pattern mismatch as an abnormality or the element that caused the mismatch in the subsequent forward step.

Therefore, according to the configuration of the embodiment of the present invention, in the playback type no-kense monitor device as described above, when a mismatch pattern is obtained, the actual operation pattern is changed to each step proceeding from the mismatch step. If the patterns match, the matching step is continued as a monitoring step for the normal pattern storage section, so when the control progresses due to the establishment of the AND condition, the monitoring device In addition to being able to prevent erroneous diagnoses due to the order in which the AND conditions are satisfied without reducing the diagnostic accuracy, the self-holding circuit also prevents malfunctions as in the past even when the transitions of mismatched patterns become diverse. It is possible to improve the reliability.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, FIG. 1 is a block diagram showing the configuration of a sequence program system monitor device according to the same embodiment, FIG. 2 is a perspective view showing an example of equipment, and FIG. 3 is a diagram showing the same monitor. The flowchart of the apparatus, FIG. 4, is a system diagram of a conventional example. 1... Operating equipment 4... Cylinder device (output element) 6.11.12
...First to third limit switches (detection elements) 10...Work 16...Operating state change detection section 17...Normal pattern storage section 18...Comparison section 19...・Comparison execution control unit 21... Abnormality diagnosis processing unit

Claims (1)

[Claims] 1. In a sequence program control system in which each step of the control operation is sequentially carried out as instructed by a sequence program that specifies the order of control operations for predetermined operating equipment,
an operating state change detection unit that detects changes in the operating states of various control elements constituting the sequence program control system and changes in the operating states of the self-holding internal relays of each control element, and detects the normality of the operating equipment; a normal pattern storage section that stores an operation pattern representing a change in the operation state of the various control elements during operation for each step in which the operation pattern changes; an operation pattern comparison section that compares the actual operation patterns of various control elements with the normal pattern storage section of the relevant step stored in the normal pattern storage section of those control elements; 1. A monitor device for a sequence program control system, comprising: an abnormality diagnosis processing unit that diagnoses an abnormality in a control state by monitoring whether there is a mismatch between a normal stored pattern and an actual operation pattern.