JP2682893B2 - Equipment failure diagnosis device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device failure diagnosis device that outputs a diagnosis result based on failure information input from various plant devices that perform complicated control operations, for example.

[Conventional technology]

FIG. 4 shows, for example, Mitsubishi Electric Technical Report (1988, No12, Vol.6).
2) P36 ~ 41 "Expert system in water and sewage plants" is a block diagram showing the configuration of a conventional device diagnostic device described in Maeda, Inoue et al., Where 1 is a color display, mouse, image processing technology, etc. An interface device having a function of answering a symptom of a failure according to a question and a function of displaying a failure cause which is a diagnostic result,
2 is a rule, table, or tree in the form of which knowledge can be easily changed / added, and the cause of failure is organized in a tree structure. A tree storage device 3 is, for example, a 32-bit microprocessor, large-capacity memory. It is a fault tree search device that enables high-speed inference and traces a fault tree according to the symptom of a fault in the target device.

Next, the operation will be described. First, the failure tree storage device 2
5 is configured by utilizing the know-how of an expert as shown in FIG. Reach the cause. Here, each node corresponds to a symptom, and if the symptom has occurred, the y branch is followed, and if not, the n branch is followed. Also,
The presence / absence of this symptom is input as failure information via the interface device 1. There are various input methods, but in the above example, the operator answers the question from the fault tree search device 3 asking whether there is a symptom.

[Problems to be solved by the invention]

Since the conventional device failure diagnosis device is configured as described above, there is a problem that correct diagnosis cannot be performed unless the cause of failure is accurately structured and stored in the failure tree storage device.

The present invention has been made in order to solve the above problems, and makes it possible to find a failure candidate having a high possibility as a failure cause even when the failure cause cannot be specified. Further, it is an object of the present invention to obtain a device failure diagnosis device which stores a failure case that has been correctly diagnosed once in a failure case database and can be used for subsequent diagnosis.

[Means for solving the problem]

An apparatus failure diagnosis apparatus according to the present invention includes an interface apparatus having a function of inputting failure information of a target apparatus and outputting a diagnosis result, a failure case database apparatus that stores failure case data of the target apparatus, and the failure information input. A similar case search device that searches for failure case data with a possibility of failure by checking the index of the failure case data, and the newly acquired failure case data as a result of the search by the similar case search device A failure case database maintenance device is provided in addition to the database device to correct the failure case database.

[Action]

The device failure diagnosis device according to the present invention matches the failure information of the target device input from the interface device with the symptom indexed to the failure case stored in the failure case database device, and the failure case in which the symptoms match Is searched for by the similar case search device, and the cause of the failure in the failure case is output to the interface device as a diagnosis result. If the cause of the failure is erroneous, a plurality of failure cases having similar symptoms are searched by the similar case device,
The failure cause in the failure case is output to the interface device as a failure cause candidate. Since the diagnosis result has a possibility as a failure cause, the operator investigates the failure cause by referring to this diagnosis result, and when the failure cause is found, the failure case is added to the failure case database. The failure case database maintenance device corrects the failure case database so that the newly created failure case database maintains consistency. As a result, the failure case database is constantly updated, and if the same symptom occurs again, correct failure diagnosis will be performed from the next time.

(Example of the invention)

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a device failure diagnosing device according to an embodiment of the present invention. In FIG. 1, 10 is a device failure diagnosing device, and 11 is a dialog for inputting failure information of a target device 15 and outputting a diagnosis result. Interface device in a form, 12 is a failure case database device that stores failure cases, 13 is a matching between the symptom input from the interface device 11 and the symptom as an index of the failure cases stored in the failure case database device 12. A similar case search device to be performed, 14 is a failure case database maintenance device, and 15 is a target device that is a target of failure diagnosis.

Next, the operation of the present invention will be described with reference to the flowchart of the device failure diagnosis device 10 shown in FIG. Before explaining, the symbols will be described.

Si: Symptom 1 / Si: Symptom is occurring 0 / Si: Symptom is not occurring {1 / S1, ..., 0 / Sn}: Occurrence of multiple symptoms Cj: Failure cause First, the operator As the failure information, the occurrence status of the failure symptom {1 / S1, ..., 0 / Sn} is input via the interface device 11. The occurrence status of the input symptom is indicated by IN (S). This input may be automatically made online from the device 15, or may be made offline by the operator. The input method is not specified (step ST1). The failure case database contains As described above, a plurality of failure cases in which a symptom occurrence state and a failure cause are paired are stored. Next, a failure case having a failure cause that completely matches the input symptom occurrence status IN (S) is searched (step ST2). If such a failure case is found, the cause of the failure case is displayed, and if not found, the result of being unknown is displayed on the interface device 11 as a diagnosis result by the exact match search (step
ST3). The operator confirms (determines) the cause of the failure based on the diagnosis result. If the diagnosis result is correct, the failure diagnosis is ended. If not correct, the diagnosis is continued (step ST4). If the diagnosis result is not correct, or if the diagnosis result is unknown, the search for the cause of failure with a high probability is started. This is the input symptom occurrence status IN (S)
This is performed by searching the failure case database device 12 for a failure case having a symptom occurrence state having a high degree of coincidence with. For example, if you Is calculated. However, the definition of the degree of matching is not limited to the search expression of the cause by the above-mentioned similarity search (step ST
Five). A plurality of cases are sorted in descending order of coincidence, and the cause of failure is displayed as a failure cause candidate on the interface device 11 (step ST6). The cause of the failure is searched for and confirmed with reference to those candidates. Determine the cause of failure C *
And This work is performed independently of the fault diagnostic device (step ST7).

Next, when the failure cause C * is determined, the failure case database is corrected. This will be described with reference to FIG. A fault that has just been diagnosed (this is now called a fault case)
The display of the failure case of the exact match search result has the failure cause C * for the input symptom occurrence status IN (S). On the other hand, if an erroneous failure cause is found in step ST2, then there must be a case of a failure cause other than C * having the same symptom occurrence status IN (S) in the failure case database at this point. become. Assuming that the cause of this failure is C +, it is now IN (S) <---> C * ... (3) IN (S) <-> C + ... (4) Failure example Will exist. Failure cause C * and C +
In order to identify the above, it is necessary to correct the symptom occurrence situations of equations (3) and (4) to different ones. Step ST2
The erroneous diagnosis was made because the description on the left side of <---> in the equation (4) was incorrect or there was insufficient information necessary to determine the cause of the failure. Therefore,
It is necessary to correct the description on the left side of equations (3) and (4). The reason as described above and the expressions (3) and (4) are displayed on the interface device 11 and the operator is requested to make a correction (step ST8A). Operator is an interface device
Make corrections via 11. The corrected result is S * <---> C * ............ (5) S + <---> C + ............ (6) (step ST8B), and the corrected result is appropriate. Confirm whether or not (step ST8C). If a failure case having a symptom S * or symptom S + symptom occurrence status exists in the failure case database (this case is called an inconsistent case), there are a plurality of failure causes having the same symptom. As a result, the failure cannot be confirmed. In that case, the reason, the expression (5), the expression (6), and the inconsistent case are displayed.
Return to step ST8B again. If there is no inconsistent case, the correction result is confirmed.

The failure case database is updated based on the correction result (step 9). The updated database will be available immediately.

[Results of the Invention]

As described above, according to the present invention, an interface device having a function of inputting fault information of a target device and outputting a diagnosis result, a fault case database device storing fault case data, and the inputted fault information. A similar case search device that searches for failure case data with a possibility of failure by examining the index of the failure case data, and a modification of the failure case database to add the newly obtained failure case data to the failure case database Since the device is configured with the failure case database maintenance device to be performed, it is possible to find a failure candidate with a high possibility as a failure cause even when the failure cause cannot be specified. Further, for a failure that has been correctly diagnosed once, the failure case is stored in the failure case database, so that if the same symptom occurs again, the correct failure diagnosis can be promptly performed from the next time. From these, there is an effect that a highly reliable device can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a device failure diagnosis apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are flow charts for explaining the operation of the present invention, and FIG. 4 is a conventional device failure diagnosis. FIG. 5 is a block diagram showing the outline of the device, and FIG. 5 is a schematic diagram for explaining the contents of the fault tree device in the conventional fault diagnosis device. In the figure, 11 is an interface device, 12 is a failure case database device, 13 is a similar case search device, and 14 is a failure case database maintenance device.

Claims (1)

(57) [Claims] 1. A failure case database device for storing failure case data including a failure cause according to failure information of a target device input from an interface device, and outputting the failure cause or failure case data from the interface device. According to the failure information of the target device input from the interface device, a similar case retrieval device that retrieves failure case data similar to the failure information from the failure case database device and outputs the failure case data from the interface device Based on similar fault case data output from the interface device, corrected fault case data is input from the interface device, and the corrected fault case data does not exist in the fault case database device. Confirm and use the failure case database device Equipment failure diagnostic apparatus and a failure case database maintenance device to be pressurized.