JP3217648B2 - Equipment failure diagnosis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an equipment failure diagnosis apparatus for performing a failure diagnosis when an abnormality occurs in equipment whose operation is controlled by a programmable controller.

[0002]

2. Description of the Related Art At present, maintenance of equipment whose operation is controlled by a programmable controller is entrusted to a person having knowledge of the equipment and specialized knowledge of maintenance, and a maintenance manual has been prepared. There are few things.

[0003]

For this reason, when an abnormality occurs in equipment, it is often the case that only a person having specialized knowledge about the equipment can cope with the equipment. It usually takes time to find out what part of the anomaly has occurred and what is the cause of the anomaly. It is difficult to pursue the fact that only emergency measures can be taken in the end, so that anomalies of the same cause may occur frequently.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to accurately and promptly grasp equipment abnormalities and to take appropriate recovery measures. To provide a diagnostic device.

[0005]

According to the present invention, there is provided a recording means for continuously recording, together with time information, input / output signals of a programmable controller for equipment control and information on the state of internal flags of the programmable controller and changes thereof. Display means for displaying the recorded information as a time chart; evaluation means for comparing the recorded information with pre-recorded information during normal operation to evaluate the recorded information; and evaluation means. Using the result of the evaluation and the failure determination knowledge base, estimating the operating state of the equipment and the cause at the time of occurrence of the failure, and instructing a corresponding recovery method, and a cause pursuit / recovery instruction means.
Is the timing to evaluate the timing of signal and flag changes.
Evaluate the number of changes with the switching evaluation unit and the cycle evaluation unit
A number-of-times evaluation unit, a state-change evaluation unit that evaluates the change itself,
The order in which changes occur in the relationship between multiple signals and flags
The order evaluation unit to be evaluated and the signal or flash at a certain time
A combination evaluation unit that evaluates combinations of
Ranaru are particularly characterized.

[0006] Further, there is provided a transfer means for transferring the information recorded in the recording means to a remote location, or the evaluation means is provided with an error.
A trend recorder that records evaluation results in chronological order for raw prediction
It is also preferred to have a step .

Further, the cause finding / restoring instruction means and the failure judgment knowledge base are constructed as an expert system, and the cause finding / restoring instruction means is provided with means for registering a new rule in the failure judgment knowledge base. It is also preferred. It is also preferable to provide a notifying means for notifying the evaluation result and the cause pursuit result by the evaluation means and the cause pursuit / recovery instructing means and the restoration instruction.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described. The present invention is for quickly pursuing a symptom or cause of an abnormality occurring in a facility 1 whose operation is controlled by a programmable controller PC. Recording means 2 for continuously recording input / output signals of a programmable controller PC for equipment control and information on the state of internal flags of the programmable controller PC and changes thereof together with time information, and information recorded on the recording means 2 As a time chart.

The recording means 2 includes, for example, a buffer 20 capable of storing the latest required time (for example, one hour) of the above information, and information stored in the buffer 20 when the data storage switch 22 is turned on. A storage area 21 that is transferred and is not automatically updated can be used. In particular, a device designed as an additional device of the programmable controller PC can be suitably used. A plurality of storage areas 21 are provided, and the data storage switch 2 is provided.
It is preferable that the storage area 21 can be switched by the second selective operation. When the operator turns on the data storage switch 22 when an abnormality occurs in the equipment 1, the latest information described above, that is, information on the input / output signals of the programmable controller PC and the status of the internal flags of the programmable controller PC and their changes, and the like. The time at which the change has occurred is stored in the selected storage area 21. Of course, the above information may be automatically transferred and recorded in the empty storage area 21 in response to the ON of the abnormal flag signal in the programmable controller PC. It is preferable that each storage area 21 has a capacity capable of storing all the information in the buffer 20, but only at least several cycles of the work executed in the equipment are stored. It may be.

The display means 3 reads information recorded in the recording means 2 and displays on / off of each contact (switch) and transition of high / low for each flag as a time chart as shown in FIG. Any means can be used as long as the recording means 2 can be used.
Is connected to a network, a personal computer or a workstation connected to the network can be used. If your computer is portable,
It may be brought to the site and connected to the recording means 2 for use. If the information recorded in the recording means 2 can be transferred through the modem 23, the information can be obtained at a remote location and displayed as a time chart. In any case, if you are familiar with the equipment 1 and its control system, by referring to this time chart, it is possible to determine what kind of abnormality is occurring, and to determine the cause of the abnormality. A high guess is possible.

Next, a description will be given of the evaluation means 4 for comparing the recorded information with the information recorded in normal operation in advance and evaluating the recorded information. A personal computer or a workstation that also serves as the display means 3 can be used. The evaluation unit 4 reads out the information during normal operation collected and recorded in advance from the internal recording device or the external recording device as described above, and compares it with the information read out from the recording unit 2 to determine which contact (switch). The ON / OFF state of the switch is strange or the amount of deviation in the ON / OFF timing is checked, and the result is displayed in a time chart format as shown in FIG. Is displayed as a specific message, or how much the change has been made and how long it has changed from the original point in time. At this time, the information during the normal operation includes the allowable time range α at the time of the change in addition to the contact name and the change time of the on / off (time from the start of the work cycle of the equipment). Means 4 determines this allowable time range α in FIG.
The display is made as shown in FIG. Note that FIG. 3A shows a case where the normal movement has occurred, FIG. 3B shows a case where the original movement has not occurred, and FIG. 3C shows a case where a delay has occurred from the original movement.

[0012] the evaluation by the evaluation unit 4, placed as to evaluate each as follows specifically. That is, timing evaluation, cycle time evaluation, rise / fall count evaluation, state change evaluation, sequence evaluation, and combination evaluation. The timing evaluation compares the on / off change timing with the reference timing with respect to the contacts that repeat the operation at the same timing, and evaluates, for example, that “the rising (falling) of a certain contact is too early (slow) msec”. In the cycle time evaluation, one cycle time is compared with the reference cycle time with respect to the operation start reference contact, and “one cycle time is
sec short (long) ”, and the rise / fall count evaluation compares the on / off change count with the reference count for a contact that repeats the same number of changes,
For example, it is evaluated that "the number of rising (falling) times of a certain contact is too large (too small) times". In the state change evaluation, the presence or absence of a change is determined for a contact that does not change on and off in a normal state. For example, it is evaluated that “a certain contact has been turned on (off)”. In order evaluation, the order of on / off change is compared with a reference order for two contacts that repeatedly change in the same order. For example, it is evaluated that "the rising (falling) of the XX contact is earlier (slower) than the rising (falling) of the XX contact".
For a plurality of contacts whose on / off combination becomes the same after a certain time from the start, the on / off combination is compared with the reference combination. If the combination is not the same, for example, "the xx contact is turned on (off) after xx msec from the start" Yes ". In addition to displaying the evaluation result simply on the screen, if the notification means 6 performs voice output or printout output, the operator can be instructed with strong appeal. it can. It should be noted that the above-described diagnosis can be performed by registering a reference pattern for each condition even for a contact whose operation is different depending on conditions (good / defective, each product).

By such an evaluation shown by the evaluation means 4, detailed symptoms of the abnormality which could not be understood only by looking at the time chart display by the display means 3 can be obtained from the equipment 1.
This makes it easy for the operator to know exactly, which makes it easy to identify and confirm an abnormal part in the equipment 1 and also to take measures. However, if the operator 1 is not familiar with the equipment 1, the evaluation by the evaluation means 4 may not indicate what caused the above-mentioned symptom and may not be able to take measures. Further, when there are a plurality of possible causes of the above-mentioned symptoms, it is difficult to grasp all the causes and move on to countermeasures even if the user is familiar.

The cause pursuit / recovery instructing means 5 is provided in order to deal with such a point. The cause pursuit / recovery instructing means 5 is provided for detecting possible abnormalities of the equipment 1 or abnormalities which have occurred before. It is constructed as an expert system based on a failure determination knowledge base consisting of a cause investigation knowledge base that summarizes the causes of failures and a recovery method knowledge base that summarizes recovery measures for each cause. The cause pursuit / recovery instructing means 5 determines the cause of the abnormality that has occurred in the equipment 1 and the recovery measures for the cause based on the dialogue input with the operator and the evaluation result by the evaluation means 4. From the base, the cause and recovery measures are instructed to the operator.

Here, when there are a plurality of candidates for the cause of a certain abnormality, all the cause candidates are displayed, and the accuracy of each cause candidate is added in, for example,% display. Since the priority of the work becomes clear, the determination becomes easy. In addition, it is preferable to indicate the position and location of the member on which the recovery measure is to be taken, instead of simply giving the instruction in the recovery measure. For example, the evaluation by the evaluation means 4 reveals that the abnormality is caused by the operation of a specific cylinder in the equipment 1, and the cause investigation / recovery instruction means 5
In addition to determining that there is an abnormality in the advance limit detection sensor of the cylinder by pursuing the cause of the above, if there is a position error of the sensor, a failure of the sensor itself, or a disconnection of the sensor as a cause candidate, the position error of the sensor Is 90%, the possibility of sensor failure is 9%, the possibility of sensor disconnection is 1%, and so on. The intended position of the sensor and the method of confirming the operation of the sensor are displayed using the drawings. In this way, when the cause is investigated and the recovery instruction is given, the cause of the abnormality can be quickly identified without the operator being familiar with the equipment 1, and
Recovery by removing the cause of the abnormality can be performed quickly and accurately. The result of pursuing the cause and the recovery countermeasure instruction are not simply displayed on the screen, but if the notification means 6 performs the voice output or the printout output, the instruction with a strong appeal to the operator is provided. It can be performed. At this time, it is preferable to automatically create a report in accordance with the operation state of the equipment and the occurrence state when an abnormality occurs.

By the way, in such an expert system, the extent to which the failure determination knowledge base is enhanced is the key to pursuing a more accurate cause, so that information on the actual cause of the abnormality and the recovery measures taken is taken. It is preferable to request the input, and it is preferable that the cause investigation / recovery instructing means 5 includes a registration unit for registering a new rule in the failure determination knowledge base.

The former may be performed by letting the operator input the actual cause among the displayed cause candidates, and the input information can be accurately reflected in the next failure diagnosis. it can. Also,
By leaving the abnormality cause information as failure history data, it can be used for grasping weak points in the equipment 1 and for reviewing and designing the equipment 1 in which similar abnormality does not occur. For this reason, it is preferable that the failure history data can be displayed as a list in the order of occurrence or a list for each contact.

Regarding the latter registration of a new rule in the failure judgment knowledge base, although it depends on the structure of the failure judgment knowledge base, generally, "IF (A) = YES THEN"
The following processing = (B) ”is to be a user interface that allows the user to insert the node described in the form of“ B ”into an appropriate position in the abnormal cause tracking tree displayed on the screen based on the cause pursuit knowledge base. preferable. In the case of this knowledge base, the above (B) corresponds to another node, own node, cause candidate list, failure location explanation screen, restoration method explanation screen, and the like.

The structure of the knowledge base and the user interface may be of any type. Here, the structure and the form are not limited. It is preferable that the user only needs to indicate a required part on the screen using a device. In the equipment failure diagnosis apparatus configured as described above, even if all of the recording unit 2, the display unit 3, the evaluation unit 4, and the cause investigation / recovery instruction unit 5 are not provided, only the recording unit 2 and the recording unit 2 In order to be able to operate only with the display means 3 or only with the recording means 2, the display means 3 and the evaluation means 4, that is, to assemble them sequentially according to the situation of the equipment 1. It is preferable that the operation mode according to the request be taken as shown in FIG.

By the way, the evaluation means 4 evaluates information for a certain period of time at predetermined intervals and evaluates the evaluation result not only when an abnormality occurs but also when the equipment 1 is operating normally. Is accumulated, abnormality occurrence can be predicted. That is, even if the equipment 1 is operating normally, the tendency of the on / off timing of a certain contact (X14C in the figure) can be grasped, for example, as shown in FIG. Thus, it is possible to predict when this deviation will deviate from the allowable time range. Further, the grasp of the number of times of use described above can be used for estimating the life of the device. Further, it is possible to recognize later that a signal operation that has not been recognized as abnormal is to be abnormal because there is a risk of manufacturing a defective product, for example.

[0021]

As described above, the present invention is provided with a recording means for continuously recording the input / output signals of the programmable controller for equipment control and the information on the state of the internal flag of the programmable controller and its change together with time information. In addition to having a display means for displaying the recorded information as a time chart, it is possible to accurately grasp the symptoms of abnormalities, and to accurately identify the cause, and The above-mentioned information is compared with the information recorded during normal operation in advance, and the evaluation means for evaluating the recorded information is provided. Therefore, even if the user is not familiar with the equipment, abnormal symptoms and abnormal parts can be obtained. Can be accurately grasped, and furthermore, the operation status of the equipment is evaluated using the evaluation result by the evaluation means and the failure judgment knowledge base. And a recovery instruction means for estimating the cause of failures and instructing the corresponding recovery method when a failure occurs, so that even those who do not have knowledge about equipment or maintenance can accurately identify the cause. In addition, the recovery process can be easily performed. Especially
Evaluation means evaluates the timing of signal and flag changes
Timing evaluation unit and cycle evaluation unit to perform
Number of evaluation units to evaluate, and state change to evaluate the change itself
Changes in the evaluation unit and the relationship between multiple signals and flags
Order evaluation unit that evaluates the order in which
Combination to evaluate combination of signal and flag status
To be able to perform evaluations more accurately because it consists of an evaluation unit
it can.

In the apparatus having a transfer means for transferring the information recorded in the recording means to a remote place, the symptom of the abnormality can be known even in the remote place, and the evaluation means is used for predicting the occurrence of the abnormality. Record evaluation results in chronological order
A device having such a trend recording means is capable of predicting the occurrence of an abnormality.

[0023]

Further, the cause pursuit / recovery instructing means and the failure judgment knowledge base are constructed as an expert system, and the cause pursuit / recovery instructing means comprises means for registering a new rule in the failure judgment knowledge base. If this is the case, the exact cause investigation can be performed more reliably. In addition, if it is provided with notification means for notifying the evaluation result and cause pursuit result and the restoration instruction by the evaluation means and cause investigation / recovery instruction means, the evaluation result and cause pursuit result for the operator, etc. Instructions can be given more clearly.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a time chart display according to the embodiment.

FIGS. 3 (a), (b), and (c) are explanatory diagrams of examples of superimposed display with a reference chart in display by the evaluation means according to the first embodiment.

FIG. 4 is a flowchart illustrating an example of an operation mode according to the embodiment.

FIG. 5 is an explanatory diagram of an example of a trend graph for predicting a failure according to the first embodiment.

[Explanation of symbols]

 1 equipment 2 storage means 3 display means 4 evaluation means 5 cause investigation / recovery instruction means

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G05B 19/048-19/05 G06F 11/22 360

Claims (5)

(57) [Claims] 1. A recording means for continuously recording input / output signals of a programmable controller for equipment control and information on the state of internal flags of the programmable controller and changes thereof together with time information, and displaying the recorded information as a time chart. Display means for performing, evaluation means for comparing the recorded information with pre-recorded information during normal operation to evaluate the recorded information, and an evaluation result by the evaluation means and a failure determination knowledge base. It is said that there is provided a cause investigation / recovery instructing means for estimating the operating state of the equipment and the cause at the time of occurrence of the failure and instructing the corresponding recovery method.
In addition, the above evaluation means is based on the timing of signal or flag changes.
A timing evaluation unit and a cycle evaluation unit for evaluating
The frequency evaluation unit that evaluates the number of changes, and evaluates the change itself
The state change evaluator and the relationship between multiple signals and flags
And an order evaluator that evaluates the order in which changes occur.
For evaluating combinations of signal and flag conditions
An equipment failure diagnosis device comprising a combination evaluation unit . 2. The apparatus according to claim 1, further comprising a transfer unit for transferring information recorded in the recording unit to a remote place.
The equipment failure diagnosis device described in the above. 3. The evaluation means evaluates for use in predicting abnormality occurrence.
2. The equipment failure diagnosis apparatus according to claim 1, further comprising a trend recording unit that records results in a time series . 4. A cause pursuit / recovery instructing means and a failure judgment notice.
Knowledge base is built as an expert system
In addition, the cause investigation and recovery instruction means
2. The equipment failure diagnosis apparatus according to claim 1, further comprising means for registering a new rule in the knowledge base . 5. An evaluation means and a cause investigation / recovery instruction means.
Notification of evaluation results, cause-finding results, and restoration instructions
2. An informing means for performing the following.
The equipment failure diagnosis device described in the above.