JPH06102927A - Diagnostic system for sequence control circuit - Google Patents

Abstract

PURPOSE:To indicate a unit to be inspected by calculating the maximum value and the minimum value of time data of respective statuses on a pattern, generating allowable continuation time arranged in the same order as the statuses, setting it to be a diagnosis reference and executing diagnosis by the comparison of the pattern and the comparison of status continuation time. CONSTITUTION:Data of plural cycles are divided into the patterns for respective cycles and continuation time, and the patterns for the respective cycles are compared with the pattern of the diagnosis reference. The continuation time of the respective steps is compared with the allowable continuation time of the judgement reference as to the cycle when the patterns coincide, and the alarm of timing abnormality is given as to a signal becoming a cause generating the status of the step as to the step which is not settled within allowable continuation time. On the other hand, the status of the initial step which does not coincide is compared with that of the corresponding step of the diagnosis reference as to the cycle when the patterns do not coincide, and the alarm of operation order abnormality is given to a signal where a difference can be recognized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diagnostic method for a sequence control circuit.

[0002]

2. Description of the Related Art Individual measurement data has the advantage of being able to save a long time in a compact manner, but has the disadvantage of having to follow a long time in order to know the situation at an arbitrary point in time. Was difficult to use for diagnosis. Further, the method of simultaneously recording a plurality of signals has a drawback that a large-capacity storage device is required to record a long time since the recording amount increases in proportion to the recording time. Therefore, the conventional sequence control circuit diagnosis method is mainly a method of extracting an abnormal signal related to a failure location after a failure stoppage that can be performed by recording progress for a short time.

[0003]

However, the conventional sequence control circuit diagnosing method has a problem in that an unstable signal, which is a symptom of failure stoppage, cannot be detected.

Therefore, it is an object of the present invention to provide a sequence control circuit diagnostic system capable of detecting an unstable signal from individual measurement data and pointing out a device requiring inspection.

[0005]

In order to achieve such an object, the present invention uses the individual measurement data at the normal time to determine the on / off state of the signal at the same time point in a predetermined signal order. A pattern in which the statuses that have been arranged are edited and statuses with different contents are arranged in a predetermined order without continuously arranging the statuses with the same contents,

A maximum value and a minimum value of time data of each status on the pattern are calculated, and an allowable continuation time is arranged in the same order as the status,

Is prepared and used as a diagnostic reference, and the diagnosis is performed by comparing the measurement data of the same format with the pattern and comparing the size of each status continuation time.

[0008]

According to the present invention, before the sequence-controlled device is stopped due to the occurrence of a failure, the operation timing of the control signal relating to the failed device is greatly changed, or the operation sequence is disturbed by noise such as chattering. Focusing attention, the individual measurement data is converted into a pattern and an allowable duration that can easily detect these unstable signals.

The pattern compactly displays the change in status, and becomes the same pattern in the sequence of the same operation sequence. Therefore, when the same sequence is repeated in a normal state, one cycle of the sequence (hereinafter referred to as cycle)
The patterns for each are often the same. There are rare cases where there are multiple patterns of equipment, but there are not many types. Therefore, when a pattern different from these patterns is detected, it can be determined that the normal state has been deviated.

Further, when noise such as chattering for a short time occurs, the pattern is greatly disturbed, so that a potential short-time abnormality can be detected without being overlooked.

As the allowable duration, the allowable width of the duration of the corresponding status is displayed with the maximum value and the minimum value. Since the fluctuation of the duration of each status tends to increase with the deterioration of the device, it can be determined that the deterioration of the device involved with the signal exceeding the predetermined allowable width.

Further, when the duration time approaches zero, it is a sign that a change in the operating sequence will occur, and it can be determined that the occurrence of a malfunction malfunction has been foretold.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows individual measurement data. In the on / off state column, the on state is 1 and the off state is 0. Recording is started from time t0, and it is recorded that the signal 1 changes from off to on at time t1. Subsequently, from time t2 to time t4, it is recorded that the signals 2 to 4 sequentially change from off to on. Similarly,
At time t5 to time t8, it is recorded that the signal 4 to the signal 1 sequentially changes from on to off, and at time t9, the recording is stopped. This figure is a record of one cycle.

FIG. 2 shows the status at time t9 in FIG. 1, that is, the final on / off state. Time t5 in FIG.
From the on / off state column from time t8 to t8, the final on / off states of the signals 1 to 4 are edited as shown in the figure.

FIG. 3 shows the result of editing the contents of FIG. 1 into a status and a duration and arranging them in time series. The step number is a temporary number for the purpose of explanation. The status in step 9 is the same as that shown in FIG. 2 and indicates the final ON / OFF state of each signal, and the duration indicates the duration until the recording is stopped. The status of step 8 is obtained from the fact that the signal 1 is in the on state before being turned off at the time t8 in FIG. 1 and the signals 2 to 4 are still in the off state. Similarly, step 7 to step 1 are edited by going back from time t7 to t0.

FIG. 4 shows a pattern as a diagnostic reference of the sequence control circuit and the result of editing the allowable duration. This diagnostic criterion is based on the case where the allowable duration is determined by adding technical consideration to the duration shown in Fig. 3 and the duration of each step based on multiple Fig. 3 format data obtained from multiple individual measurement data. It may be created by finding the minimum and maximum values of.

The diagnosis after editing the diagnostic criteria of FIG. 4 is executed as follows. First, the individual measurement data is edited into the format shown in FIG. Next, the data of a plurality of cycles is divided into a pattern and a duration of each cycle, and the pattern is compared with the diagnostic reference pattern for each cycle.

For the cycle in which the patterns match,
Compare the duration of each step with the allowable duration of the judgment criteria, and for the step that does not fall within the allowable duration, the signal indicating a state different from the previous step, that is, the signal that caused the status of that step to be abnormal Is issued. Further, it is also possible to calculate the average value and the variation of the duration time from the data of a plurality of cycles and issue an alarm from the tendency.

For the cycles in which the patterns do not match, the statuses of the first step that does not match and the corresponding step of the diagnostic criteria are compared, and a signal indicating a difference is issued and an alarm indicating an abnormal operation sequence is issued. It is possible to remove the abnormal step and repeat the pattern comparison for the cycle in which the failure is not stopped and the operation is naturally recovered and the operation is continued.

Since the increase in the number of times of occurrence of the same pattern that does not match the diagnostic criterion pattern is likely to lead to a failure stop, it is possible to rank the alarms according to the occurrence rate.

[0022]

According to the present invention, by recording the sequence control signal, it is possible to detect the disturbance of the on / off operation timing due to the malfunction of the equipment related to the signal.
It is possible to point out the equipment requiring inspection before the breakdown is stopped.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of individual recording data.

FIG. 2 is an explanatory diagram of a final status.

FIG. 3 is an explanatory diagram of status and duration.

FIG. 4 is an explanatory diagram of diagnostic criteria.

Claims (1)

[Claims] 1. A plurality of signals constituting a sequence control signal, each time it is activated, an identification symbol of the activated signal,
ON / OFF state before or after operation or before or after,
Based on the data obtained by measuring the operation time or the elapsed time from the previous operation (hereinafter referred to as individual measurement data), the ON / OFF state of the signal at the same time point is arranged in the order of a predetermined signal. A status layout diagram (hereinafter, referred to as a pattern) in which status data (hereinafter, referred to as a status) is edited and statuses having different contents are arranged in a predetermined order without continuously arranging statuses having the same content, and a pattern Calculate the maximum value and minimum value of the same on / off state duration (hereinafter referred to as duration) of each status of, and create an allowable duration that is arranged in the same order as the status, and set it as the diagnostic reference. A feature is that diagnosis is performed by comparing the measured data at another point converted to the format with the pattern and comparing the size of each status duration. Sequence control circuit diagnosis method.