JPH04260902A - Device for diagnosing failure - Google Patents

Abstract

PURPOSE:To judge the existence of a true failure when a practical state is different from set operation condition data and to judge the sort of the failure. CONSTITUTION:A failure judging part 107 compares the control operation of a control part 104 monitored through a monitor part 105 with operation control data stored in a storage part 106 and judges whether a failure is generated or not. When the judging part 107 judges the generation of a failure, a failure inferring part 108 infers the sort of the failure and the validity/invalidity of the failure judgement based upon a rule (inference data) stored in a rule storing part 109.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosis device for external equipment in a programmable controller.

0002

2. Description of the Related Art FIG. 7 is a block diagram showing a conventional failure diagnosis device. In the figure, 101 is a programmable controller, 102 is a failure diagnosis device, 103 is an external device, 104 is a control section of the programmable controller, and 10
5 is a monitor unit that monitors the control operation of the control unit 104;
06 is a storage unit that stores operating condition data; 107 is a failure determination unit that compares the operating condition data in the storage unit 106 with the control operation monitored by the monitor unit 105 and determines whether a failure has occurred; 110 is an input signal , 111 are output signals. Further, FIG. 8 is a flowchart showing the processing of the failure determination unit 107, FIG. 2 is an explanatory diagram showing the contents of the operating condition data stored in the storage unit 106, and FIG. 4 shows an example of an operation time chart of the external device 103.

Next, the operation will be explained. External device 10
3 is shown in FIG. 4 by the programmable controller 101.
Assume that the operation shown in A) is performed. At this time, it is assumed that the operating condition data is as shown in FIG. In the programmable controller 101, the control unit 104
The input signal 110 and output signal 111 are controlled. At the same time, the monitor unit 105 monitors the states of the input signal 110 and output signal 111 controlled by the control unit 104 (i.e.,
control operation) and passes it to the failure determination unit 107.

On the other hand, the failure determining section 107 is activated when the programmable controller 101 starts operating. First, the device status is input from the monitor unit 105, and the number N of the operating condition data is set to 1 (S801, S802).
). Next, the operating condition N (initially, N=1, so operating condition 1) is retrieved as operating condition data from the storage unit 106, and it is determined whether it matches the state of the state number n (S80
3, S804). If they match, increase n by 1 (
S805). On the other hand, if they do not match and n=1, it is determined that the states of the input signal 110 and output signal 111 have not yet been input from the monitor unit 105, and the process waits for the start state (S806). If they do not match and n is not 1, it is determined that a failure has occurred (S807). Furthermore, in order to determine whether any other failures have occurred, 1 is added to the operating condition number N, and it is determined whether it is the last one (S808,
S809). If it is not the last, return to S803 and compare with the next operating condition. If it's the last time, it will end.

Since the above processing is performed, for example, if the operation shown in FIG. 4 (A) is performed, states 1 to 8 of operating condition 1 and states 1 to 8 of (A) are are consistent, and it is not determined that there is a failure. However, if the operation shown in FIG. 4B is performed here, in state 6, X2 is O
Since it does not turn FF, it is judged to be a failure.

[0006]

[Problem to be Solved by the Invention] Conventional failure diagnosis devices are configured as described above, so if there is even a slight difference between the set operating condition data and the actual operation, it will be judged as a failure and will cause problems. There were problems in that even a timing difference could cause a failure, and that it could not be used in applications where the order changed depending on conditions. There was also the problem that it was impossible to make a determination when there were multiple factors.

[0007] This invention was made to solve the above-mentioned problems, and it is possible to determine whether it is a true failure when the set operating condition data differs from the actual state, and to The purpose of this invention is to obtain a fault diagnosis device that determines the type of fault.

[0008]

[Means for Solving the Problems] A fault diagnosis device according to the present invention is a fault diagnosis device for diagnosing a fault in an external device connected to a programmable controller by monitoring the control action of a programmable controller. monitoring means for monitoring;
Comparing a storage means storing a plurality of control operation conditions corresponding to a plurality of control operations of the programmable controller and a control operation condition of the storage means corresponding to the control operation of the programmable controller monitored via a monitor means,
Using a combination of a failure determination means that determines a failure in different cases, and a determination result of a plurality of control operations of the programmable controller and a plurality of corresponding control operation conditions when a failure is determined by the failure determination means, The apparatus is equipped with a failure determining means for determining the type of failure and whether the failure judgment is correct or incorrect.

[0009]

[Operation] In the fault diagnosis device according to the present invention, when a fault is determined by the fault determining means, the fault determining means combines the respective determination results of a plurality of control operations of the programmable controller and a plurality of corresponding control operation conditions. is used to determine the type of failure and whether the failure determination is correct or not. In other words, by having a rule for failure determination, it is easy to diagnose the failure of a machine that operates differently depending on a slight timing difference or condition.

0010

[Embodiment] An embodiment of the present invention will be explained with reference to the drawings. In FIG. 1, 101 is a programmable controller;
02 is a failure diagnosis device, 103 is an external device, 104 is a control unit of a programmable controller, and 105 is a control unit 10
106 is a storage unit that stores operating condition data; 107 compares the operating condition data in the storage unit 106 with the control operation of the monitor unit 105 to determine whether a failure has occurred; 108 is a failure determination unit, 108 is a failure inference unit, 109 is a rule storage unit that stores rules that are inference data, 110 is an input signal, and 111 is an output signal. 2 is an explanatory diagram showing the contents of the operating condition data stored in the storage unit 106, FIG. 3 is an explanatory diagram showing the contents of the inference data, FIG. 4 is an operation time chart of the external device 103, and FIG. 5 is a process of the failure determination unit 107. Flow: FIG. 6 shows the processing flow of the failure inference unit 108.

Next, the operation will be explained. External device 10
3 is shown in FIG. 4 by the programmable controller 101.
Assume that the operation shown in A) is performed. At this time, it is assumed that the operating condition data is as shown in FIG. The programmable controller 101 controls an input signal 110 and an output signal 111 by a control unit 104. At the same time, the monitor section 105 monitors the states (ie, control operations) of the input signal 110 and output signal 111 controlled by the control section 104 and passes them to the failure determination section 107 .

On the other hand, the failure determination section 107 is activated when the programmable controller 101 starts operating. First, the device status is input from the monitor unit 105, and the number N of the operating condition data is set to 1 (S501, S502).
). Next, the operating condition N (initially, N=1, so operating condition 1) is retrieved as operating condition data from the storage unit 106, and it is determined whether it matches the state of the state number n (S50
3, S504). If they match, increase n by 1 (
S505). On the other hand, if they do not match and n=1, it is determined that the states of the input signal 110 and output signal 111 have not yet been input from the monitor unit 105, and the system waits for the start state (S506). If they do not match and n is not 1, a failure flag is set in the operating condition N (S50
7). Furthermore, in order to determine whether any other failures have occurred, 1 is added to the operating condition number N, and it is determined whether it is the last one (
S508, S509). If it is not the last, return to S503 and compare with the next operating condition. If it is the last step, the process advances to S510 for fault diagnosis and inference of the fault is made.

Referring to FIG. 6, the failure diagnosis at S510 will be explained in detail. First, r representing the rule number of inference data stored in the rule storage unit 109 is set to 1 (S601). Next, it is determined whether it is the last rule (S602). If it is not the last, analyze rule r (
S603). The rule is in an if-then format such that if operating condition 1 is a failure and operating condition 2 is a failure, then limit switch 1 is failure, as shown in rule 1 of FIG. Next, it is determined whether the condition is satisfied based on the analysis result of rule r (S604), and if the condition is not satisfied, r is incremented by 1 to check the next rule, and the process returns to S602 (S604).
605). On the other hand, if the condition is satisfied, the then part of the corresponding rule r is output and the process ends (S606). Furthermore, if it is determined in S602 that this is the last rule, the process ends.

[0014] In the embodiment, the combination rule of whether the operating condition is faulty or non-faulty has been explained, but it may also be combined with the ON/OFF state of the output signal.

[0015]

As described above, according to the present invention, since the present invention is configured to perform fault diagnosis based on fault combination rules, it has the advantage that it can be applied to fault diagnosis of equipment whose operation changes depending on conditions.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a failure diagnosis device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the contents of operating condition data stored in a storage unit.

FIG. 3 shows the contents of inference data stored in a rule storage unit.

FIG. 4 is a time chart showing the operation of external equipment.

FIG. 5 is an operation flow of a failure determination unit.

FIG. 6 is an operation flow of a failure inference unit.

FIG. 7 is a block diagram showing a conventional failure diagnosis device.

FIG. 8 is a flowchart showing processing of a conventional failure determination unit.

[Explanation of symbols]

101 Programmable controller 102
Failure diagnosis device 103 External equipment
104 Control section 105 Monitor section
106 Storage unit 107 Failure determination unit
108 Failure inference unit 109 Rule storage unit
110 Input signal 111 Output signal

Claims (1)

[Claims] 1. A failure diagnosis device for diagnosing a failure of an external device connected to the programmable controller by monitoring the control operation of a programmable controller, comprising: a monitor means for monitoring the control operation of the programmable controller; A storage means storing a plurality of control operation conditions corresponding to a plurality of control operations is compared with a control operation condition of the storage means that corresponds to a control operation of the programmable controller monitored via the monitor means, and if the control operation conditions are different, a failure determining means for determining a failure when the failure has occurred; and a combination of the determination results of the plurality of control operations of the programmable controller and the plurality of corresponding control operation conditions when the failure determination means determines that the failure has occurred. A failure diagnosis device comprising: a failure determination means for determining the type of failure and whether the failure judgment is correct or incorrect.