JPH07104839A - Abnormality diagnostic system of production equipment - Google Patents

Abstract

PURPOSE: To make it possible to diagnose the abnormality of a production equipment without necessitating the knowledge of a user. CONSTITUTION: A computer 3 is connected to a programmable controller 2 for controlling the operation of the production equipment 1 and this abnormality diagnostic system automatically detects the abnormal state of the production equipment 1 and performs display relating to the detected abnormal state by the computer 3. The computer 3 fetches the program from the controller 2, analyzes it and also fetches input/output data relating to the operation sequence of the production equipment. From the input/output data and an analyzed result, the abnormality of the production equipment is detected based on a knowledge database provided beforehand. Instruction information relating to the detected abnormal state is supplied to the user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality diagnosing system which self-diagnoses an abnormality such as a failure of production equipment and gives an instruction contributing to a user's coping.

[0002]

2. Description of the Related Art For example, a target product can be produced by sequentially executing a series of sequences such as execution of a predetermined process, transfer to a next processing unit, execution of a process in the next processing unit, and the like. In the production equipment to be carried out, automation is progressing, and a series of production steps are almost fully automatically executed by a program of a control device for controlling the production equipment.

A control device used in such a production facility is called a PLC (Programmable Logic Controller), and a program for controlling a sequence of a series of production steps is incorporated in this PLC. ing. Although this program is created by the user, it is created in a language called a ladder language, which is different from the language used in a normal computer.

By the way, since this PLC program controls the sequence, when an abnormality such as a failure occurs in the production equipment, the program is to warn the fact of the occurrence of the failure as a part of the sequence. Although it is possible to build a
It is difficult to incorporate even abnormality diagnosis that gives a user a work instruction as a program. Also,
A failure that can generate an alarm must be predicted in advance as production equipment, and even an unexpected failure cannot be alarmed.

For this reason, the user himself has to carry out the failure diagnosis, but since the recent production equipment is complicated, even the expert can easily find out the failure diagnosis. Therefore, a method of diagnosing the failure of the production equipment using a stand-alone computer is adopted.

In this case, what is called an expert system is often used as software for fault diagnosis. This expert system is one of the fields of artificial intelligence application. It is a system that incorporates knowledge and know-how in solution into a computer to support higher-level work that is equivalent to or higher than that performed by a skilled person or expert. It is.

When this expert system is used for failure diagnosis, knowledge necessary for the diagnosis is input to the computer in advance. Then, in the actual failure diagnosis, the computer sequentially asks the user questions regarding the failure. The user sequentially inputs the answers to the question into the computer. From the input information of the user, the computer diagnoses the failure based on the knowledge and know-how (knowledge database) accumulated in the computer itself, finds a solution, and outputs the information of the user.

[0008]

As described above, the conventional abnormality diagnosis system is based on the premise that knowledge necessary for the diagnosis is input to the computer in advance, and furthermore, the computer using the expert system. Since the user must answer the question output by the user, the user needs to be familiar with the structure of the production equipment and the sequence, and not everyone can handle it. In view of the above points, the present invention has a problem that the equipment has stopped for a long time. In view of the above points, the present invention will provide an abnormality diagnosis system for production equipment that can be easily handled by an amateur. It is what

[0009]

In order to solve the above problems, a system for diagnosing abnormalities in production equipment according to the present invention includes a programmable controller for controlling the operation of production equipment.
An abnormality diagnosis system in which a computer is connected and an abnormal state of the production equipment is automatically detected by the computer, and a display relating to the detected abnormal state is performed, wherein the computer is operated by the control device. , The program is imported and analyzed, and input / output data related to the operation sequence of the production equipment is imported,
From the data and the analysis result, an abnormality of the production facility is detected based on a knowledge database provided in advance, and instruction information related to the detected abnormal state is provided to the user. And

[0010]

In the present invention having the above structure, the computer takes in the program and data from the input / output port from the control device, that is, the PLC, analyzes the program, and refers to the data from the input / output port. However, the computer itself performs so-called Q & A to perform abnormality diagnosis, and informs the user of the location of the abnormality,
Provide work instructions.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the abnormality diagnosis system for production equipment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of the abnormality diagnosis system of this example. In FIG. 1, 1 is a production facility, 2 is a PLC, and by the program of PLC2,
The operation sequence of the production facility 1 is controlled.

During the operation sequence control of the production equipment 1, the PLC 2 gives an operation command Cm to the production equipment 1, and at that time, various information Se such as sensor output from the production equipment 1 is input / output as I / O data (input / output). The control command for the next operation sequence is sent to the production facility 1 while confirming the sensor output Se, etc., and the desired sequence is executed.

For example, in the case of a sequence for moving an article at a predetermined position to another position, first the PLC 2
Sends a command to the production facility 1 to move the article moving means to a predetermined position. Then, it is detected from the sensor output whether or not it has correctly moved to a predetermined position. After confirming that the moving means has moved to the predetermined position, PL
C2 sends a command to place the article on the moving means. When the sensor output confirms whether or not the article is placed on the moving means, the PLC 2 sends a command to the production facility 1 to move the moving means to another position. The sensor output confirms whether or not the position has moved to another position, and this sequence ends.

Actually, the PLC 2 receives the information on the on / off of the relay provided corresponding to each sensor as the sensor output Se of the I / O data. Further, each sensor (that is, relay) is provided with a number or the like for identification.

In the sequence as described above, when an abnormal situation occurs, for example, when the moving means is stopped halfway due to some trouble, the production facility 1
Will stop and the PLC 2 will stop the program in that state. Where the program stopped can be known from the sensor output, but the program is not included in the PLC. If the trouble is a trouble assumed in advance as production equipment, an alarm buzzer is sounded or an alarm lamp is turned on as a part of the sequence of the PLC 2. However, in the case of a trouble that cannot be predicted in advance, no alarm is given and the system remains stopped.

In order to automatically diagnose such an abnormal condition and give a proper work instruction to the user, the present invention provides:
The computer 3 is connected to the PLC 2. In this case, the computer 3 is connected to a display device 4 for display for giving the user information about an abnormal portion and a work instruction for dealing with the abnormality. Further, a key operation unit 5 operated by a user is connected to the computer 3 so as to start abnormality diagnosis. In addition,
The blocks in the computer 3 are functional blocks in consideration of processing functions in the computer 3.

In the case of this example, the computer 3 uses an expert system as program software for failure diagnosis. However, in the present invention, unlike the conventional case, the PL
The program of C2 is analyzed and recognized by this expert system, and the sensor output of the production facility 1 is also referred to so as to find a failure location and automatically give a work instruction to the user.

In this case, the PLC2 program uses a ladder language which is not used in a normal computer, as described above, so it is necessary to convert this into a language that can be analyzed by an expert system. . Therefore, the computer 3 is functionally composed of an abnormality diagnosing unit 20 including an expert system and a data capturing and data converting unit 10.

[Explanation of Abnormality Diagnosis Operation] As described above, when the production equipment has stopped operating, the user operates the key operation unit 5 to execute the abnormality diagnosis program by the computer 3. When started, the computer 3 sends a data transmission request RQ from the data transmission request generation unit 30 to the PLC 2. Upon receiving the data transmission request RQ, the PLC 2 transmits the program PR and I / O data (status or comment) such as sensor output from the production facility 1 to the computer 3.

The computer 3 loads the control program of the PLC 2 into the storage unit 11P of the data loading and data conversion unit 10 and loads the I / O data into the storage unit 11D. Then, in the data acquisition and data conversion unit 10, the program of the PLC2 of the storage unit 11P is
The mnemonic conversion unit 12 converts the mnemonic code and files it in the storage unit 12M. Next, this mnemonic code is transferred to the expert conversion unit 1 in order to deliver it to the failure diagnosis unit 20 composed of an expert system.
In 3, the data is converted into the data of the format for the expert system and filed in the storage unit 13M.

Now, for example, if the ladder program of PLC2 is as shown in FIG. 2 and it means "if A and C or B and C, then output D is obtained", Is converted into the format for the expert system, the result is as shown in FIG.

In this way, the PLC program data converted into the format for the expert system,
The I / O data in the storage unit 11D is delivered to the analysis / diagnosis unit 21 of the abnormality diagnosis unit 20.

As described above, the abnormality diagnosing unit 20 includes
The knowledge database unit 23 is provided, and information for abnormality diagnosis of the production facility 1 is stored in advance as the knowledge database. In the analysis / diagnosis unit 21, the PLC
Based on the data of the program of 2 and I / O data, the production facility 1 is searched for abnormalities, and the knowledge database is used.
The diagnosis result is given to the detected abnormality. Then, based on the diagnosis result, the instruction information generator 22 generates operation instruction information for the user and displays it on the display 4.

[Detailed Description of Abnormality Diagnosis] An example of the operation of abnormality diagnosis in the abnormality diagnosis unit 20 which is an expert system is shown in the flowchart of FIG. Below, referring to this flowchart,
A more specific operation example will be described.

In the abnormality diagnosing system of this example, the trouble (abnormality) that occurs is referred to in advance as a trouble expected as production equipment (hereinafter referred to as a predictable trouble).
Trouble search is performed separately for troubles that are not expected as production equipment (hereinafter referred to as unknown troubles). In this case, the predictable trouble is a trouble that can be judged by the warning lamps such as red and yellow provided in the production equipment. It is a trouble when it comes.

As shown in FIG. 5, in the abnormality diagnosis procedure in the abnormality diagnosis section 20, first, a predictable trouble is searched (step 101).

In this example, the PLC2 program is standardized, and the number used in the program (the number given to the control relay corresponding to the sensor) is used.
Has a specific meaning as shown in the table of FIG. 4, for example, and the abnormality diagnosis unit 20 starts the search for abnormality diagnosis from these numbers. Predictable troubles are found in this search.

Then, in the next step 102, it is judged whether or not the predictable trouble is found. If the predictable trouble is found, the process proceeds to step 103, and if the predictable trouble is not found. As will be described later, the process proceeds to step 110 and moves to the process flow for the unknown trouble.

[Example when predictable trouble occurs]
Here, a case will be described as an example where a predictable trouble occurs in which the production facility is in the emergency stop state with the number 13100. In this state, as shown in the table of FIG. 4, the control relay IR13100 (IR indicates a control relay) is “ON”, this is detected in step 102, and the process proceeds to step 103.

In step 103, the number 13100
The PLC2 ladder program is analyzed. In the case of this example, the PLC2 program (ladder program) relating to this emergency stop is as shown in FIG. 6, and the data formatted for this as an expert system is as shown in FIG. Become.
That is, it is a program of the condition for the output “13100”. In the numbers shown in FIG. 6, IR0
0000 is an emergency stop switch, and IR000
01 is a reset switch. This is stored as knowledge in the knowledge database unit 23.

In step 103, a tree-structured expert object is output from the analysis result as is well known as an expert system.
00 ”and the process proceeds to step 104. FIG. 8 shows the expert object of the tree structure.

In step 104, the reason why the status of the relay IR13100 is ON in the tree of FIG. 8 is searched with reference to the I / O data. The order of the search is to start from path 1 and then search path 2 in FIG. Here, in order to prevent the search from becoming endless, when the actual input / output data (in this case, the statuses of IR00000 and IR00001) are found, the search is stopped by paying attention to these states.

In this case, IR00000 and IR000
01 is both “off”, the IR13100 uses a-contact (normally open contact), and IR00000 and I
R00001 uses b contact (normally closed contact). In FIG. 7, IR indicates a normally open contact and IN indicates a normally closed contact. From this, it is determined that IR13100 is turned "on" because both IR00000 and IR00001 are "off". Next, step 1
Go to 05.

"IR0000" is "OFF" means that the emergency stop switch is pressed or a wire break occurs, and "IR00001" is "OFF" when the reset switch is set. Means that is not pressed. This is registered in the knowledge database unit 23 in advance. Therefore, in step 105, the following message is created and displayed on the display.

[Example of message] Emergency SW is pressed or disconnection Reset SW is not pressed. Check these points.

After step 105, step 106 is performed.
To complete the abnormality diagnosis. The user sees the above message and maintains the production equipment.

[Unknown trouble has occurred] If no predicted trouble is found in step 102, that is, if the trouble that has occurred is an unknown trouble, the routine proceeds to step 110, and the abnormality diagnosis is performed as follows. To do.

In this example, as shown in FIGS. 9 and 10, a processing target object is placed on the chuck by using a transfer machine (moving means), and then the next processing target object is placed on another chuck. Let's consider a sequence consisting of the steps up to and returning to the original chuck position. It is assumed that the input data of the I / O port at this time is assigned as shown in FIG. A switch or relay IR is provided corresponding to each I / O address, and the selected switch or relay IR is turned on,
Data is input / output.

As a trouble, it is assumed that the load ready signal of the input address X108 of the I / O port is not input and the equipment is stopped. In this trouble state, there is no indication by the alarm lamp, and the production equipment does not recognize it as a trouble.

The load ready signal is programmed so that the head down of the sequence is executed after the load ready signal is obtained. FIG. 12 shows the ladder program of this head-down portion. Further, FIG. 13 shows a state in which this ladder program is converted into a format for an expert system. At this time, the relay IR0010
Since 8 is "off" (because no load ready signal comes in), the control relay IR15008 is "off" and the program is stopped here.

In step 110, the place where the program stops in the sequence of FIG. 9 is searched. This can be done by searching the states of the control relays of each sequence through while creating the expert object. In the case of the above-mentioned unknown trouble, since the relay IR 15008 is “off”, it is found in step 111 that the program is stopped in the process part.

When the portion where the program has stopped is detected in this way, the process proceeds to step 112 and, in the same manner as the above-mentioned predictable trouble, the number 1 in which the trouble has occurred.
From the program part of 5008 (see FIGS. 12 and 13), an expert object having a tree structure as shown in FIG. 14 is generated, and the reason why the relay IR15008 is “off” in the order of path 10 → path 11 is explained. Find out. As mentioned above, the expert system will continue to search until the actual input / output is reached, resulting in the relay IR00108 "off" for this example.

Next, in step 104, the result detected in step 112 is combined with the knowledge database to generate an instruction to the user, and in step 105, the message is displayed on the display 4. After step 105, the routine proceeds to step 106, and this abnormality diagnosis flow is ended.

In the above example, the case where the expert system is used as the program software for abnormality diagnosis has been described, but it goes without saying that usable software is not limited to this.

Although the instruction to the user is displayed on the display, the instruction may be given to the user by voice.

[0047]

As described above, according to the present invention, since the computer connected to the PLC performs the abnormality diagnosis by itself and gives the instruction to the user, it has the conventional knowledge. Anyone can do so-called troubleshooting, which was only done by anyone. Therefore, the time during which the production facility is stopped due to an abnormality is reduced, the movability of the production facility is improved, and the production amount can be expected to increase.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a production facility abnormality diagnosis system according to the present invention.

FIG. 2 is a diagram showing an example of a PLC program.

FIG. 3 is a diagram showing the program of FIG. 2 converted into a format for an expert system.

FIG. 4 is a diagram showing an example of a PLC program number and its specific meaning.

FIG. 5 is a flowchart of an example of an abnormality diagnosis operation.

FIG. 6 is a diagram showing an example of a PLC program.

FIG. 7 is a diagram showing the program of FIG. 6 converted into a format for an expert system.

FIG. 8 is a diagram showing an example of a tree-structured expert object.

FIG. 9 is a diagram showing an example of a sequence of production equipment.

FIG. 10 is a diagram showing an example of a sequence of production equipment.

FIG. 11 is a diagram showing an example of I / O port allocation.

FIG. 12 is a diagram showing an example of a PLC program.

FIG. 13 is a diagram showing the program of FIG. 11 converted into a format for an expert system.

FIG. 14 is a diagram showing an example of a tree-structured expert object.

[Explanation of symbols]

1 Production Equipment 2 PLC (Control Device) 3 Computer 10 Data Acquisition and Data Conversion Unit 12 Mnemonic Symbol Conversion Unit 13 Expert System Format Conversion Unit 20 Abnormality Diagnosis Unit 21 Analysis Diagnosis Unit 22 Instruction Information Generation Unit 23 Knowledge Database section

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tetsuro Shibasaki Singapore 2263 Tuas Road 1 Singapore Private Limited Limited (72) Inventor Huntart Jundra Singapore 2263 Tuas Road 1 Singapore 2263 Sony Assurance 1 Private Limited Display Device (Singapore) Private Limited (72) Inventor Sen Ching Chai Singapore, Singapore 2263 Tuas Road 1 Sony Display Device (Singapore) Private Limited (72) Inventor E Meisan Singapore Singapore 2263 Tuas Road 1 Sony Display Device (Singapo ) Private Limited (72) Inventor Chang Chee Haw Singapore 2263 Tuas Road, Singapore 2263 Sony Display Devices (Singapore) Private Limited (72) Inventor Ram Eikyon Eric Singapore 2263 Tuas Road 1 Within Sony Display Devices (Singapore) Private Limited

Claims (3)

[Claims] 1. A computer is connected to a programmable controller for controlling the operation of a production facility, the computer automatically detects an abnormal state of the production facility, and displays a display relating to the detected abnormal state. An abnormality diagnosis system configured to perform, wherein the computer loads and analyzes the program from the control device, loads input / output data regarding an operation sequence of the production facility, and collects the data and the analysis result. From the above, the abnormality diagnosis system of the production facility is characterized in that the abnormality of the production facility is detected based on a knowledge database provided in advance and the instruction information related to the detected abnormal state is provided to the user. . 2. The abnormality diagnosis system for production equipment according to claim 1, wherein the computer constructs a tree-structured diagnosis procedure from an analysis result of a program of a control device, and the diagnosis procedure is used as the input / output port data. An abnormality diagnosis system for production equipment, which is characterized in that the abnormality diagnosis system is executed by referring to. 3. An abnormality occurring in the production equipment is divided into a first abnormality that can be predicted as the production equipment and a second abnormality that is not predicted, and the abnormality diagnosis is searched for by using the first abnormality. The abnormality diagnosis system for production equipment, wherein the abnormality diagnosis system is for the second abnormality when the abnormality is not the first abnormality.