JPH0675244B2 - Monitor device for sequence program control system - Google Patents

Description

The present invention relates to a monitor device of a sequence program control system.

(Prior Art) A sequence program control is generally known in which a program designating an operation sequence of equipment to be controlled is assembled and each step of control is sequentially advanced according to the program. Then, such sequence control is used in a machine tool assembly line, a machine tool, or the like in order to automatically perform the operation of the next step in accordance with the operation of the previous step.

Therefore, in this sequence control, when monitoring, that is, monitoring whether or not the control is normally performed, a program for this monitor is incorporated in the program that controls the operation of the equipment, and an alarm is issued when an abnormality occurs. There is the idea of doing it. However, with this device, it is necessary to change both the program for operating the equipment and the program for monitoring each time the equipment is changed, and the overall program capacity for both the operation and the monitor is enlarged.

On the other hand, a playback type monitor device is known. This one stores operation patterns of each component of the sequence control circuit when the equipment is normally operated in advance, and matches the operation patterns stored when the equipment is actually operated. Whether or not there is a match is sequentially checked, and if there is a mismatch, an abnormality is indicated. Therefore, in the case of this playback type monitor, regardless of whether the equipment is operating normally or not, if the patterns do not match, an abnormality is pointed out.

Further, as another conventional technique, when monitoring the machining state of the machine tool, the detection data obtained from the machining state detector is sequentially compared with the diagnostic data registered in advance, and an alarm is issued when they do not match, There is also a system in which an operator judges whether or not the mismatched data can be accepted as normal based on this alarm and can register it as diagnostic data (see, for example, JP-A-58-143938).

(Problems to be Solved by the Invention) The present invention is intended to solve the problem that in the above-mentioned playback type monitor device, even if the equipment is operating normally, if the patterns do not match, an abnormality is diagnosed. To do.

That is, for example, when two limit switches that detect the state of equipment are both turned on in any order, that is, AND
If there is a cylinder device that operates when the (logical product) condition is satisfied, the transition of the operation pattern that satisfies the AND condition is determined in two ways depending on which of the above two switches is turned on first,
There are three cases including the case where they are turned on at the same time.
Considering the case where both switches are repeatedly turned on and off and turned on together, the types of pattern transitions are infinite). However, since there is only one pattern transition that is stored as normal during normal operation of the equipment, there is a problem that other pattern transitions are diagnosed as abnormal even if there is no problem in the operation of the equipment. In addition, diversification of equipment operation such that equipment operation patterns differ depending on the type of workpiece to be processed causes the same problem as described above.

Also, although there is no hindrance to the progress of equipment operation, for example, if the work is supplied early and that is detected by the limit switch, and the operation pattern changes and becomes different from the memory, it is diagnosed as an abnormality. Will end up.

On the other hand, in the case of the conventional method of adding data by intervention of an operator each time an abnormality is pointed out, not only this operator's intervention and judgment are required, but the point of pattern mismatch is reduced by the addition of data. However, it is impossible to solve the problem of warning an abnormality if there is a pattern mismatch even during normal operation.

(Means for Solving Problems) As means for solving the above problems, the present invention provides a change detection unit for detecting a change in the operating state of each element constituting the sequence program control system, and a normal operation of equipment. In the normal pattern storage unit that stores the operation pattern of each element in each step in which the pattern changes, the actual operation pattern obtained by the detection by the change detection unit and the normal pattern in the normal pattern storage unit are compared and controlled. A diagnostic processing unit for diagnosing the state, and when an operational pattern different from the normal pattern is obtained by this diagnostic processing unit, it is determined whether or not there is an abnormality in the operation of the equipment thereafter based on the progress status of the transition of the operational pattern. When the operation confirmation unit and the operation confirmation unit determine that there is no abnormality, the different operation patterns described above are registered as normal operation patterns in the normal pattern storage unit. The present invention provides a monitor device for a sequence program control system, which includes a normal pattern registration unit.

(Operation) In the case of the above monitoring device, the equipment is operated to sequentially monitor the actual operation pattern, and when an operation pattern different from the one previously stored in the diagnosis processing unit is obtained, the operation confirmation unit thereafter Also, when it is determined that the transition of the operation pattern has progressed and there is no abnormality in the operation of the equipment, the normal pattern registration unit registers the different operation pattern as a normal operation pattern in the normal pattern storage unit.

In other words, the diagnosis in the playback monitor is different from general plant failure diagnosis, and when the equipment is operating without stopping, even if an operation pattern different from the memory is obtained, it can be regarded as normal. The present invention utilizes this fact and automatically learns this as a normal operation pattern even if the above different operation patterns are obtained, provided that the equipment is operating without abnormality. I'm trying to make a difference.

(Effect of the invention) Therefore, according to the present invention, in the playback type monitor device, when an operation pattern different from the memory is obtained,
A plurality of operation patterns that are recognized as normal are provided by providing an operation check unit that checks the operation of the equipment after that and a normal pattern registration unit that registers the above operation pattern as a normal operation pattern when there is no abnormality in operation. When there is such an operation pattern, this operation pattern can be automatically learned each time it is obtained, preventing an abnormal alarm from being issued when there is no problem in the operation of the equipment. The same operation pattern can be immediately treated as a problem without confirming the progress of the operation of the equipment, and the diagnostic accuracy or reliability of the monitor can be improved.

(Example) Hereinafter, the Example of this invention is described based on drawing.

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

In the figure, 1 is equipment for controlling its operation,
The control system of the equipment 1 includes a plurality of detection elements (for example, limit switches) that detect the state of the equipment 1, and an output element (for example, a cylinder device) that performs machining or conveyance of a work or the like.

2 is a signal (IN / OU
I / O status input section 3 for inputting T), 3 is a change detection section for detecting a change in the above I / O status by the output from the I / O status input section 2, that is, a change in the operating pattern of all elements, and 4 is It is a normal pattern storage unit. This normal pattern storage unit 4 causes the equipment 1 to perform a normal operation in advance, and the operation pattern at that time is changed (the pattern of at least one element is changed).
I / O status changes) It is stored at each step.

Reference numeral 5 denotes a diagnostic processing unit that compares the actual operation pattern obtained by the change detection unit 3 with a normal pattern obtained from the normal pattern storage unit 4 to diagnose the control state, and the diagnostic result is the diagnostic result output unit. 6 and the learning control unit 7. In this case, the diagnosis processing unit 5 extracts the normal pattern of the corresponding step from the normal pattern storage unit 4 every time the change detection unit 3 detects a change in the I / O state and the control step shifts. Comparison control section for comparing the operation pattern with the operation pattern of No. 3, a determination section for determining whether or not the operation pattern matches the normal pattern as a result of this comparison, and the operation result when the determination result does not match with the diagnosis result output section 6 The learning control unit 7 is provided with a diagnosis unit.

When the diagnosis processing unit 5 points out an inconsistent operation pattern, the learning control unit 7 temporarily stores subsequent operation patterns including the inconsistent operation pattern. Then, after that, an operation confirmation unit 9 for checking whether or not the equipment 1 operates normally, and a normal pattern for receiving the operation normality confirmation and registering the non-matching operation pattern in the normal pattern storage unit 4 as a normal operation pattern Registration department 10
With.

That is, when the operation confirming unit 9 is diagnosed by the diagnosis processing unit 5 that the operation abnormality of the output element has not been diagnosed and the operation pattern has transitioned for a predetermined step, the equipment 1 is operating normally. The determination is made, and the temporary storage unit 8 is given a command to stop the storage of subsequent operation patterns, and the normal pattern registration unit 10 is given a command to register the operation patterns in the temporary storage unit 8.

In the case of this example, the operation confirming unit 9 operates when the equipment 1 operates without stopping for one cycle (from the step from the starting point to the ending point of the operation of the equipment 1), that is, the operation of the starting step. When the operation pattern of the end step appears after the pattern appears, the equipment 1 is determined to be operating normally. Also,
The normal pattern registration unit 10 registers all the operation patterns of one cycle in which the inconsistent operation patterns have occurred as the second (or third, fourth) normal pattern transition.

Further, when the learning control section 7 receives a reset signal from the abnormality confirmation input section 11, the learning control section 7 cancels (stops) the work of temporarily storing the operation pattern, confirming the 1-cycle operation, and registering the normal pattern. This reset signal is used when the operator judges that the above-mentioned operation pattern disagreement is a true abnormality based on the output of the diagnosis result output unit 6 as when the equipment 1 has stopped operating. Given by twelve.

Therefore, the operation flow of the monitor device is as shown in FIG.

First, the monitoring is started by the start signal, and the change detector 3 detects whether or not the I / O state has changed. When there is a change, the operation pattern is compared with the normal pattern of the corresponding step (S1, S2). ). Then, when the operation pattern is diagnosed as abnormal due to pattern mismatch, for example,
This is given to the diagnosis result output unit 6, and if an abnormality confirmation is input, the monitor is stopped (S3, S
Four).

Then, if the abnormality confirmation input is not made, a change in the I / O state is observed, and if there is no change, the abnormality confirmation input is awaited (S5). If there is a change in the I / O status, the operation pattern previously diagnosed as abnormal is temporarily stored, and there is no error confirmation input until it is confirmed that the equipment 1 has operated normally for one cycle. Each time there is a change in the I / O status, the operation pattern is stored in sequence (S6, S
7). When the one-cycle operation is confirmed, the previously temporarily stored operation pattern is registered as a normal pattern, and the output of the previous abnormality diagnosis is cleared (released) (S8, S9).

Next, learning control will be described based on a specific example of equipment.

FIG. 3 shows a specific example of the above equipment. That is, this one sends the workpiece W from the preparation station 13 to the conveyor 16 driven by the motor (M) 15 by the feeding means (SOL1) 14, and the conveyor 16 carries out the processing station 17
The work W sent to is processed by the processing means (SOL2) 18 and taken out. Preparation station 13 above, conveyor
Limit switches (LS1 to LS4) 21 to 24 for detecting workpieces are provided at the starting point and the intermediate point of 16, respectively, and the machining station 17 is provided with a limit switch (LS5, LS5, LS6) 25, 26 are provided. In addition, a safety mat 27 is provided near the processing station 17.
Is provided, and a switch (safety mat S) 28 that outputs a facility stop signal when an operator gets on is provided. Further, this equipment can be started from a plurality of operating states by an automatic operation button when the switch (automatic / manual) switching (automatic switching S) of a separately provided control panel is automatic.

The control circuit of the above equipment is shown in FIG.

When the automatic operation button 30 is pressed, the relay means 31a to 31c are activated, and the energization is maintained unless the automatic changeover switch 32, the safety mat switch 28, and the stop switch (stop S) 33 are activated.
When the work W is in the preparation station 13 and not in the conveyor 16 and the processing station 17 and the processing means 18 is at the backward end (LS1 and LS5 are on, LS2 to LS4 are off), the feeding means 14 operates the relay means 14a, 14b. To send the work W to the conveyor 16.

The conveyor 16 sends the work W to the processing station 17 when the work W is above it and not at the processing station 17 (LS2 or LS3 is on, LS4 is off) and the motor 15 is activated by the relay means 15a and 15b. . When the machining means 18 is not at the forward end (LS6 is off), the workpiece W is at the machining station 17 (LS4 is on), and the reverse relay means 18c is not operating, the forward relay means 18d, 18e When the work moves forward to process the work W and reaches the forward end (LS6 is ON), the limit switch for detecting the backward end (LS5)
Is off and the forward relay means 18f is not operating,
The reverse relay means 18a, 18b actuate and move backward.

1 stored in the normal pattern storage unit 4 for the above equipment
The cycle pattern (first normal pattern) is shown in the following table.

When the automatic operation button 30 is pressed while the work W is in the preparation station 13 but not in the conveyor 16 and the processing station 17 and the monitor is started in the state (step 1) in which the feeding means 14 is operated, the work W is the preparation station. 13
When the LS1 changes from (1 → 0) by being sent out from, the operation pattern at that time is compared with the normal pattern of step 2. Since these two patterns match, it is judged to be "normal", and when LS2 changes (0 → 1) and SOL1 changes (1 → 0), it is compared with the normal pattern in step 3.

Hereinafter, each time the operation pattern changes as described above,
The operation pattern is compared with the updated normal pattern of the step to determine whether the operation pattern is normal.
When the supply of the work W to the preparation station 13 is delayed in the state of 1), LS3 changes (0 → 1) first, and then L
S1 will change (0 → 1). The transition of the operation pattern at this time is as shown in the following table.

That is, the operation pattern of (e) is compared with the normal pattern of step 5, but both patterns do not match in LS1 and LS3. Therefore, although the diagnosis result of abnormality is output, the above-mentioned states of LS1 and LS3 do not affect the operation of the conveyor 16, so that the equipment continues to operate without stopping. Since there is no particular problem with this operation, the abnormality confirmation button 12 is not pressed, and each time the operation pattern changes, the operation patterns after (e) above are sequentially and temporarily stored.

Then, the cycle from (i) to (wo) is completed, and then the same cycle from (i) to (wo) (or the cycle in the first normal pattern stored in the normal pattern storage unit 4). When the process proceeds without delay, it is confirmed that the equipment has normally operated for one cycle, and the operation pattern in Table 2 is registered in the normal pattern storage unit 4 as the second normal pattern.

Therefore, thereafter, the operation pattern is first compared with the first normal pattern, and if there is a mismatched operation pattern, it is compared with the second normal pattern.

When starting the monitor, the equipment receives the start input and searches the normal pattern storage section for a normal pattern that matches the I / O status at that time, so that the equipment is at the origin (for example, step 1) of its operation. Even if it does not exist, the monitor can be started from the step of the above-mentioned normal pattern in synchronism with the current condition of the equipment, and the diagnostic output is initialized at this start.

Further, in the comparison between the operation pattern and the normal pattern, the pattern mismatch in the corresponding step may be judged as abnormal as in the above-mentioned embodiment, but when the mismatch in the corresponding monitoring step occurs, the other patterns are matched. If there is a normal pattern to be matched, the step to be monitored is changed to the matching position so that the subsequent monitoring is performed, and it is judged as abnormal only when there is no matching normal pattern.
Other determination methods may be used.

In addition, in outputting the diagnosis result, the result can be output only when it is determined to be abnormal in comparison with all the normal patterns of the first, second, ... If there is an abnormality in the comparison with the pattern, it may be pointed out, and the comparison result with the second and third normal patterns may be output in response to the subsequent request from the operator.

Furthermore, when there is an operation pattern that is not stored in memory, only the operation patterns that are different from the previously stored normal pattern may be temporarily stored. Furthermore, when newly registering as a normal pattern, instead of registering all operation patterns for one cycle, only the operation patterns that are not stored in memory (from (e) to (e) in the previous example) are registered. Alternatively, if the number of steps is the same, only the operation pattern that is not stored (only (e) in the previous example) may be registered.

In addition, when confirming the operation of the equipment when an operation pattern that is not stored in the memory occurs, one cycle (in the previous example, (f)
→ (wo) → (b) → (e)), that is, when the equipment operates without stopping until there is at least the step (e) above and there is a transition in the operation pattern, the equipment operation is normal. You may judge.

Furthermore, when an operation pattern that is not stored in memory occurs, the operation pattern until the step where the corresponding non-matching element (LS1 and LS3 in the previous example) changes next time (up to (f) or (to) in the previous example) If there is a transition of, the operation of the equipment may be judged to be normal.

Furthermore, when the operation pattern is newly registered as a normal pattern, the output of the previous abnormality diagnosis is cleared, but the output may be recorded.

[Brief description of drawings]

Drawing shows an embodiment of the present invention, FIG. 1 is a block diagram showing the configuration of a monitor device, FIG. 2 is a flow chart of learning control of a monitor, FIG. 3 is a plan view showing an example of equipment, and FIG. FIG. 3 is a sequence control circuit diagram of the same example. 1 ... Equipment, 2 ... I / O status input section, 3 ... Change detection section, 4 ... Normal pattern storage section, 5 ... Diagnostic processing section, 9
…… Operation check part, 10 …… Normal pattern registration part.

Claims (1)

[Claims] 1. In a sequence program control system in which each step of control is sequentially advanced by a program designating an operation sequence of equipment, a change detecting section for detecting a change in operating state of each element constituting the control system, and equipment. The normal pattern storage unit that stores the operation pattern of each element during each normal operation of each step in which the pattern changes, the actual operation pattern obtained by the detection by the change detection unit, and the normal pattern of the normal pattern storage unit. The diagnostic processing unit that compares the control status and the diagnostic processing unit, and when this diagnostic processing unit obtains an operation pattern that is different from the normal pattern, determines whether there is an abnormality in the operation of the equipment after that in the progress status of the operation pattern transition. Based on the operation confirmation unit that determines based on this, and the operation confirmation unit determines that there is no abnormality, the different operation pattern described above is corrected as a normal operation pattern. Sequence program control system of the monitoring device, characterized in that it comprises a normal pattern registration unit for registering in the pattern storage unit.