JPH05181511A - General-purpose fault detector for sequence control - Google Patents

Abstract

PURPOSE:To specify the request of a fault part by comparing a standard pattern with a current pattern while using a fault part specifying means by counting the time from start to end at every group and detecting the fault of an element group in the unit of the group. CONSTITUTION:At positions corresponding to respective rollers 3 of a carriage roller conveyer 2, plural sensors 4 are arranged for detecting the head position of a steel plate 1, for example. These respective sensors 4 are divided into groups at every process, and detecting signals from the sensor group 4 at every group are respectively inputted to a sequence controller 5. The detecting signals of the respective sensors 4 are inputted through a sequencer 6 for input to a personal computer 7 and stored in a storing means 8b, and a pattern by one cycle is registered as a standard pattern 8a. A fault part specifying means 11 compares the standard pattern 8a with a current operational pattern 8b and when difference is present, the element is specified by adding the priority orders of fault parts succesisvely from the sensor 4 closest to the fault point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sequence control general-purpose fault detection device capable of detecting a fault in a sequence control device such as a sensor, a solenoid valve or a motor used in a hot-dip galvanizing apparatus for steel sheets.

[0002]

2. Description of the Related Art Conventionally, there is a failure detection system incorporated in a sequence for detecting a failure in a sequence control device such as a sensor, a solenoid valve and a motor used in a hot dip galvanizing apparatus for steel sheets. In this, a program such as time monitoring can be incorporated into each sequence to display the occurrence of a failure and its part. In addition, there is a device that records the progress of sequence control for a long time, analyzes the location of the failure in detail, and tries to find the cause.

[0003]

Among the conventional failure detection systems described above, in the former system, a failure detection program must be created for each system, and each time the sequence is modified or changed, The failure detection system program also needs to be maintained.

However, the maintenance of the program for the failure detection system, which is required for a long time, is neglected because it is not directly related to the operation of the apparatus, resulting in a failure detection system far from the sequence for operating the apparatus. However, a lot of energy is required to perform the maintenance.

Further, in the latter system of the related art described above, since the operating states of the sensors, solenoid valves, etc. can be recorded for a long time, it is necessary for the maintenance personnel to analyze them in detail, and the breakdown occurs online. The cause cannot be displayed.

In view of the above, an object of the present invention is to provide a sequence control general-purpose fault detection device capable of easily detecting a fault in a sequence control device and identifying a faulty part in a short time.

[0007]

In order to achieve the above object, the present invention divides a plurality of elements such as a plurality of sensors, solenoid valves, motors, etc. into a plurality of groups, and makes each group of elements a plurality of elements. In a sequence control device for performing sequence control through a plurality of steps for each operation mode, storage means for storing an operation pattern of an element group for each group during operation of the sequence control device, and an operation pattern stored in the storage means From 1 for each group
Registration means for extracting an operation pattern from the start to end of a cycle and registering it as a standard pattern, and storing the operation pattern of the element group for each group by the storage means, from the start to the end of one cycle for each group The failure detection means for detecting the failure of the element group in the group unit by measuring the time of each group and exceeding the preset time for each group, and the failure detection means detects the failure of the element group in the group unit. When the standard pattern and the current operation pattern are phase-matched with each other, the standard pattern of each element is compared with the current operation pattern step by step within a range of several steps before the final step of the current operation pattern. If there is a difference between the standard pattern and the current operation pattern, the failure part is sequentially If there is no difference between the standard pattern and the current pattern, the signal that creates the next step of the step corresponding to the final step of the current operation pattern is used as the cause of the failure in the standard pattern. And a failure part specifying means for specifying the element of.

[0008]

According to the present invention, the failure detecting means measures the time from the start to the end of one cycle for each group and exceeds the time set in advance for each group, so that the element group of each group is exceeded. The failure of can be detected.

When the failure detecting means detects the failure of the element group in group units, the failure part specifying means determines the number of steps before the step in which the failure is detected in the final step of the pattern of the current operation pattern. The standard pattern of each element and the current pattern are compared step by step within the range of steps, and when there is a difference between the standard pattern and the current pattern, the failure parts are prioritized in order from the element closest to the failure point. When there is no difference between the standard pattern and the current pattern, the element of the failure part is specified by using the signal that makes the step next to the failure occurrence step in the standard pattern as the cause of the failure.

[0010]

Embodiments of the present invention will be described below with reference to FIG. FIG. 1 shows a schematic configuration in the case where the present invention is applied to a molten steel galvanizing apparatus for steel plates. Steel plate 1
Are configured so that they can be transported in a predetermined direction by the transport roller conveyor 2. A plurality of, for example, 140 sensors 4 for detecting the tip position of the steel plate 1, for example, A, B, C, D, ... , Each of these sensors 4 is divided into groups for each processing step, and the sensor group 4 for each group is
The detection signals (ON / OFF signals) from the above are input to the existing sequence control device 5, respectively.

In the sequence controller 5, the sensor group 4 is sequence-controlled through a plurality of steps for each operation mode of the transport roller conveyor 2.
The detection signal of each sensor 4 is input to the personal computer 7 via the input sequencer 6 and can be stored in the storage means 8b inside the personal computer 7. And storage means 8b
When the operation patterns for several cycles are stored in, the normal operation pattern for one cycle can be extracted and registered as the standard pattern 8a.

Further, inside the input sequencer 6, there is a timer 15 for monitoring the operating time for each group, and the time measurement is started when the start signal of each group is detected, and it is set in advance for each group. The failure detection means 10 for detecting a failure of the group of sensors 4 by not detecting the completion signal of each group even if the failure detection set time 16 is exceeded, and this failure detection means 1
When a failure of an element group in a group unit is detected by 0, the standard pattern 8a and the current operation pattern 8b are phase-matched, and then one step is performed within a range of several steps before the final step of the current operation pattern 8b. The standard pattern 8a of each sensor 4 and the current operation pattern 8b are compared with each other, and when there is a difference between the standard pattern 8a and the current operation pattern 8b, the priority of failure parts is given in order from the sensor 4 closest to the failure point. And standard pattern 8
When there is no difference between a and the current operation pattern 8b, the signal that creates the next step of the step corresponding to the final step of the current operation pattern 8b in the standard pattern 8a is used as the cause of the failure and the element 4 of the failure site is determined. And a failure part specifying means 11 for specifying

A keyboard 12 for inputting data into the personal computer 7 and a printer 13 and a display 1 for printing and displaying the output of the failure part specifying means 11, respectively.
4 are provided.

In such a configuration, the present operation pattern 8b is such that the sequence controller 5 operates normally if a compression recording method is used in which the ON / OFF signal of the sensor 4 is recorded every time an event occurs and the duration of the ON / OFF pattern is recorded. Signals may be recorded chattering even while driving. From operation pattern 8b to 1 for normal operation
Unnecessary chattering can be removed by examining the on / off pattern and the duration on the display 14 when extracting the cycle and registering it in the standard pattern 8a.

The failure detection means 10 considers the time from the start signal to the end signal for each group, and when it is operating normally, the maximum time is the failure detection set time 1
6 is set, and the value of the group operation time timer 15 that measures the time from each start signal to the end signal for each group is compared with each group in the comparison means 17, and the group operation time timer 15 When the time exceeds the failure detection set time 16, the failure of the group of sensors 4 can be detected.

The failure part specifying means 11 is the failure detecting means 1
When a failure of the sensor group in a group unit is detected by 0, the standard pattern 8a and the current operation pattern 8b are phase-matched, and then one step at a time in the range of several steps before the final step of the current operation pattern 8b. Standard pattern 8a of each sensor 4 and current operation pattern 8b
If there is a difference between the standard pattern 8a and the current operation pattern 8b, the failure parts are prioritized in order from the sensor 4 closest to the failure point, and the standard pattern 8a and the current operation pattern 8b are compared. When there is no difference, the element of the failure portion is specified by using the signal that creates the step next to the step corresponding to the final step of the current operation pattern 8b in the standard pattern 8a as the cause of the failure. here,
If an ON / OFF signal of the sensor 4 in the sequence control is recorded every time an event occurs, it can be generally expressed as follows. Here, 1, 2, 3 ... n, ...; Step, T; Time when the same state continues, A, B, C, D ,.
Elements such as a solenoid valve and a motor are shown. This can be expressed as a general formula as follows. F _hij (a _j , b _j , c _j , d _j , ...) = T _hi (j) (1) In this equation (1), the equal sign simply connects the right side and the left side. is there. F: indicates a set of 1 and 0 of each element. T: Indicates the duration of each step. h: indicates the number of a group of an aggregate of elements such as sensors. i: Indicates the operation mode of the device. j: represents the number of steps from the start of the signal aggregate of the elements defined by h, i. For h group, i mode, and n steps, the following (2)
The formula holds. F _hin (a _n , b _n , c _n , d _n , ...) = T _hi (n) (2) Next, the standard data for one cycle of the h group and i mode in normal operation is <F _hij (A _j , b _j , c _j , d _j , ...)> = <T _hi (j)> (3) Noise such as chattering needs to be removed from the standard data obtained by the equation (3). The required operation time from step 1 to step n

[0017]

[Equation 1] Required from. Since the operation time of each step varies, a constant H is used to determine whether the operation is normal.
And the equation (5) is used as the judgment value.

[0018]

[Equation 2]

For a failure due to a longer operating time compared to the equation (5) during operation, or a failure determined by the operator, the equation (3) is compared with the equation (2) representing the operating state. , By knowing the difference between the equation (3) and the equation (2), the cause of the failure can be grasped. For this reason, h and i in the equation (3) when the failure occurs are specified, and F _hij and <F _hij
> Phase adjustment. When a failure occurs in p steps, the state at the time of failure is F _hip (a _p , b _p , c _p , d _p , ...) = T _hip

Although it can be expressed as follows, T _hip is indefinite because it is a failure and can be ignored. Since the sequence control is used, the cause of the failure is considered to be within several steps of p steps. However, F _{hi1 to} F _hip may include noise such as chattering. The following measures are taken to remove this noise. The first treatment is 10 msec to 2 in duration T within the previous 5 steps from p step.
When 0 msec is absent or one, there is no chattering and phase matching is performed.

In the second procedure, if there are two consecutive 10 msec to 20 msec in the duration T within the previous 5 steps from the p step, the chattering is checked as possible chattering.

Regarding the first treatment, the phase alignment with the standard data is performed for the 5 steps before the p step. This phase matching may be _performed by comparing T _hij . That is,

[0023]

[Equation 3] From the results of the expressions (6) to (10), the phases match when the minimum value is obtained.

[0024]

[Equation 4]

When this equation (11) shows the minimum value, F _hi (j) from step p to step p-5 and pq
<F _hi (j) from step to pq-5 steps
> Is compared, and the first element that does not match is the cause of the failure. Alternatively, if there is no discrepancy, the element that is set after the pq step to the pq + 1 step is extracted from the standard data as the cause of the failure. The second treatment can be expressed as follows.

[0026]

[Equation 5]

In the equations (12) to (15), (1
The left side of equation (2) matches the left side of equation (14), and (1
If the left side of the equation (3) and the left side of the equation (15) match, it is understood that chattering has occurred. Here, a signal that does not match the equations (14) and (15) is extracted, and this is used as a failure signal. If the above-mentioned first and second measures are not established, it is not chattering, and the failure point is extracted by the first measure.

As described above, noise such as chattering is removed from the standard data of 1) and (3), and 2) and (4).
The elements that cause the failure are automatically extracted by the expressions (15). Here, the operation of the above-described embodiment, particularly the operation pattern recording method will be described with reference to FIG.

FIG. 2 shows changing elements 1-1, 1-2, 1-3, 1-4, 2-1 and 2 such as sensors and solenoid valves.
(2, 2-3, 2-4) is divided into two groups of four, (a) shows a recording process, and (b) shows this recording result. 1. Processing contents of input sequencer 6 1) The input sequencer 6 transfers ON / OFF signals of sensors, solenoid valves, etc. to the personal computer 7.

2) The time from the start signal to the end signal for each groove is measured, and if the end signal does not come in even if the preset time is exceeded, the input sequencer 6 sends a failure detection signal to the personal computer 7. These two processes are always executed. For the failure detection time of each group in 2), set the maximum time in normal operation after actually operating the equipment. 2. Processing contents of personal computer 1) Normally, the signal received from the sequencer 6 is recorded for each group. 2) When receiving a failure detection signal, first determine the group containing the abnormal equipment from the start signal of each group and the timing of receiving the failure detection signal.

Next, the standard operation pattern in the operation mode at that time of the group is compared with the operation pattern at that time, an abnormal signal is detected, and a message (abnormality content, treatment content) registered in advance in the signal is displayed. .. 3. Signal recording method by the personal computer 7 As shown in FIG. 1, the ON / OFF state in the group and the duration of the state are recorded. 4. Failure detection method by sequencer 6 The sequencer 6 monitors the time for each group and detects a failure.

In the case of FIG. 1, the signal 1-1 is included in one group.
When the signal changes from OFF to ON, the timer 15 starts counting from zero, and when the signal 1-2 changes from ON to OFF, the timer 15 stops counting. If this timer 15 exceeds 25 seconds, it is judged as a failure.

In the second group, when the signal 2-1 changes from OFF to ON, the timer 15 starts counting from zero, and when the signal 2-2 changes from ON to OFF, the timer 15 stops counting. This timer 15 is 2
If it exceeds 0 sec, it is judged as a failure. 5. Group judgment method including signal of faulty equipment by PC 7

When the personal computer 7 receives a failure signal from the sequencer 6, there is a start signal before the end signal and there is no end signal, and the group in which the time from the start signal to the failure signal matches the failure detection time fails. Judge as a group that includes equipment signals.

The present invention is not limited to the embodiments described above. For example, in the embodiment, the sensor is taken as an example of the element of the sequence control device, but other solenoid valves, motors, etc. may be used. Also, PC 7
The configuration of is not limited to the embodiment.

[0036]

As described above, according to the present invention, it is possible to provide a sequence control general-purpose fault detection device capable of easily detecting a fault of a sequence control device and identifying a faulty part in a short time.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a sequence control general-purpose fault detection device according to the present invention.

FIG. 2 is a diagram for explaining the operation of FIG.

[Explanation of symbols]

1 ... steel plate, 2 ... conveying roller conveyor, 3 ... roller, 4 ...
Sensor, 5 ... Existing sequence control device, 6 ... Input sequencer, 7 ... Personal computer, 8 ... Storage means, 9 ... Comparison means, 10 ... Failure detection means, 11 ... Failure part identification means, 1
2 ... Keyboard, 13 ... Printer, 14 ... Display, 15 ... Operating time measuring means, 16 ... Failure detection setting time, 17 ... Time comparing means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mikio Sudo 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Toshio Nakamaru 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Date Inside the steel pipe company

Claims (1)

[Claims] 1. A sequence control in which elements such as a plurality of sensors, solenoid valves, and motors are divided into a plurality of groups, and the element group of each group is subjected to sequence control through a plurality of steps for a plurality of operation modes. In the apparatus, a storage unit that stores an operation pattern of an element group for each group while the sequence control device is operating, and an operation from start to end for one cycle for each group from the operation pattern stored in the storage unit Registration means for extracting a pattern and registering it as a standard pattern; and storing the operation pattern of the element group for each group by the storage means, measuring the time from the start to the end of one cycle for each group, and for each group in advance. Fault detection that detects faults in the group of elements by exceeding the time set in When the failure of the group of elements is detected by the output means and the failure detection means, after performing the phase matching between the standard pattern and the current operation pattern, the steps of several steps before the final step of the current operation pattern are performed. The standard pattern of each element is compared with the current operation pattern step by step in the range. If there is a difference between the standard pattern and the current operation pattern, the failure parts are prioritized in order from the element closest to the failure point. , And when there is no difference between the standard pattern and the current operation pattern, the signal that creates the next step of the step corresponding to the final step of the current operation pattern in the standard pattern is used as the cause of the failure to identify the element of the failure site A sequence control general-purpose fault detection device comprising: a fault site identification means for identifying.