KR102505378B1 - Aggregation server generation method based on OPC UA standard information model of smart factory assets - Google Patents

Abstract

A method for creating an Aggregation Server based on the OPC UA standard information model of smart factory assets is provided. The Aggregation Server generation method according to an embodiment of the present invention acquires UANodeSet-based modeling information of smart factory assets from XML files, extracts information about smart factory assets from the obtained modeling information, and extracts information about smart factory assets. Create OPC UA Clients to connect to OPC UA Servers, and create Aggregation Servers that collect data received from OPC UA Servers through OPC UA Clients. This enables data integration of the factory OT layer based on international standard technology, saves time and cost in establishing a data integration system that is the basis for smart factory advancement, and adds systems according to process changes, Able to respond flexibly to changing circumstances.

Description

Aggregation server generation method based on OPC UA standard information model of smart factory assets {Aggregation server generation method based on OPC UA standard information model of smart factory assets}

The present invention relates to smart factory/manufacturing related technologies, and more particularly, to a method for collecting and managing information of distributed assets (equipment, facilities, etc.) in a smart factory.

In order to configure a flexible manufacturing system, it is necessary to be able to maintain cost efficiency while producing a variety of products on a small scale. Traditional forms of production are somewhat less capable of reacting to change.

For example, when there is a change or addition of an asset, there is no or negligent management of the existing asset, so the same work is repeated or duplicated in the linking process, and a lot of time and personnel are invested in the system integration process for central control. .

Accordingly, the ability to collect data is required in order to oversee and control all elements involved in production within the manufacturing site.

On the other hand, when different communication standards are applied between multiple assets, difficulties and costs arise in integrating and simplifying interfaces.

Korean Patent Publication No. 2018-0069402 (2018.06.25) Korean Patent Registration No. 1940747 (2019.01.15)

The present invention has been devised to solve the above problems, and an object of the present invention is to provide information on distributed assets (equipment, facilities, etc.) in a factory each having an OPC UA server in an XML format based on the OPC UA standard information model. It is to provide a way to create an information model and collect it into one OPC UA server using modeled XML files of each asset.

According to an embodiment of the present invention for achieving the above object, an Aggregation Server generation method includes obtaining UANodeSet-based modeling information of smart factory assets from XML files; Extracting information about smart factory assets from the acquired modeling information; Creating OPC UA Clients to connect to OPC UA Servers of smart factory assets; and generating an Aggregation Server that collects data received from OPC UA Servers through OPC UA Clients.

In the acquiring step, modeling information of smart factory assets may be obtained from XML files stored in a specific folder.

In the extraction step, NodeId, which is an identifier for a variable having an ID of a smart factory asset, access information of OPC UA Server, and data, can be extracted.

In the extraction step, necessary information may be extracted from modeling information by objectifying an XML file using a schema file for UaNodeSet.

In the extraction step, the XML file can be deserialized into a Java object, and modeling information in the XML file can be called and extracted in the form of a Java object and method.

OPC UA Clients can subscribe to receive when the data of OPC UA Servers changes.

In the OPC UA Server creation step, the AddressSpace of OPC UA Servers can be automatically configured using UANodeSet-based modeling information.

According to an embodiment of the present invention, the aggregation server creation method may further include: synchronizing variable data of the aggregation server by reading data possessed by the OPC UA servers. And, the synchronization step may be performed when a DataChangerEvent occurs.

On the other hand, according to another embodiment of the present invention, the Aggregation Server generation system includes a storage unit in which XML files are stored for UANodeSet-based modeling information of smart factory assets; And extract information about smart factory assets from modeling information obtained from XML files stored in the storage unit, create OPC UA Clients to connect to OPC UA Servers of smart factory assets, and through OPC UA Clients A processor that creates an Aggregation Server that collects data received from OPC UA Servers; includes.

On the other hand, according to another embodiment of the present invention, the Aggregation Server creation method includes generating OPC UA Clients for connecting to OPC UA Servers of smart factory assets; and generating an Aggregation Server that collects data received from OPC UA Servers through OPC UA Clients.

On the other hand, according to another embodiment of the present invention, the Aggregation Server creation system includes a communication unit connected to communicate with smart factory assets; and a processor that creates OPC UA Clients for connecting to OPC UA Servers of smart factory assets and creates an Aggregation Server that collects data received from OPC UA Servers through OPC UA Clients.

As described above, according to the embodiments of the present invention, data integration of the factory OT layer based on international standard technology is possible, and time and cost are saved in building a data integration system that is the basis for smart factory advancement. , can flexibly respond to changes in the system due to process changes.

In particular, according to the embodiments of the present invention, it is possible to easily, quickly, and flexibly respond to the most basic and essential function of data acquisition for configuring a smart factory.

Further, according to the embodiments of the present invention, a special development process is not required for centralization of factory assets, and a non-expert can easily acquire necessary data if he/she knows only the information history of the asset.

In addition, according to the embodiments of the present invention, as the flexible production system becomes a hot topic, assets can be included or excluded at any time, or whenever a change that can be combined in a different form occurs, costly and time-consuming technical implementation System integration for data acquisition is easily possible if only the information modeling file for the asset exists.

In addition, according to the embodiments of the present invention, as a solution to improve the edge gateway, an unlimited number of manufacturing assets are integrated into one system, and only one gateway PC capable of executing a program is required.

Figure 1. Architecture for centralizing data on the manufacturing floor
Figure 2. System configuration diagram
Figure 3. OPC UA Basic Architecture and Information Model
Figure 4. Part of DataType contents of UANodeSet
Figure 5. View modeling information for an asset
Figure 6. Objectification process of JAXB utilization and modeling information using schema
Figure 7. Part of the objectified class
Figure 8. Modeling information acquisition source code
Figure 9. OPC UA Client creation and connection source code part
Figure 10. OPC UA Server creation source code part
Figure 11. Server AddressSpace creation process

Hereinafter, the present invention will be described in more detail with reference to the drawings.

Recently, as small-lot production of various products and customized production have become the hot topic of smart factory technology, the ability to respond to the flexibility of physical changes in the field is required. In addition, in order to build a smart factory environment, collecting information on assets that contribute to the production process is the most basic.

An embodiment of the present invention provides a solution that can systematically manage data generated from assets existing in the manufacturing production line and build an environment that can be flexibly linked with upper applications for smart factory advancement.

In particular, OPC UA among industrial standard technologies is used to reduce the cost of interface construction in system integration and to respond to the liquidity of assets for the production process. If the information model for managing production facilities is initially configured, it is possible to easily add and delete data to the centralized system for data collection, reducing time and cost in building an integrated system.

Using the server/client structure that is the basis of OPC UA, real-time data can be collected from assets existing in the industrial field. In particular, it includes features that can respond to the ever-changing shopfloor environment in line with flexible production, which is an essential element of recent smart factories, and it is possible to easily build a data centralization system through the configuration of information models for assets.

1. Manufacturing data centralization system

- Edge Computing technology supports computing at the edge of network configuration

- Centralize real-time data generated from physical assets in the field

- Data collection technology that is the most basic of smart factories

- Provides a platform to store, analyze, and utilize individual data generated from each device

Figure 1 is the basic architecture for data centralization at the manufacturing site, where the centrally located Aggregation Server serves as a bridge between various assets and applications at the site.

Aggregation Server guarantees the flexibility of facility operation from the point of view of an application program that has to manage the entire facility as changes, additions, and transfers are frequent at manufacturing sites.

2 is a system configuration diagram for modeling information for managing assets in the field and building an aggregation server based on the modeled data.

In an embodiment of the present invention, modeled asset information is received in XML form, and the modeling information is used to connect to each asset to perform the DA (Data Access) function of the Aggregation Server.

2. OPC Unified Architecture

- Industrial communication protocol for industrial automation developed by the OPC Foundation

- IEC62541 international standard

- Basic structure of server/client communication

- Technologies focused on communicating with industrial equipment and systems for data collection and control

In an embodiment of the present invention, the infrastructure layer is configured and implemented in FIG. 3 by using a Java SDK API that provides a Java OPC UA Stack among UA APIs.

A new information model for an asset can be created based on the OPC UA data model, which is derived from the OPC UA base information model. The specification of the information model serves as an industry standard model for solving industry-specific problems. In Figure 3, it corresponds to the Information Models stage, and designates a basic information model that defines comprehensive objects used for real-time and historical data variables and alerts above the infrastructure layer.

Basically, there is an OPC UA standard information model and a model created in collaboration with a manufacturing company. In an embodiment of the present invention, an OPC UA infrastructure is configured by using an information model based on the UA standard information model.

3. Acquisition of modeling information and objectification

3.1 Modeling Information

3.1.1 UANodeSet

UANodeSet is a specification for data type and structure specified by the OPC Foundation, and can be written as an XML document as illustrated in FIG. 4 .

In an embodiment of the present invention, based on UANodeSet, information about assets to be configured as Aggregation Server is modeled, and information is acquired by importing the modeled nodeset file.

3.1.2 Acquisition of modeling information

Modeling information for assets created based on UANodeSet is stored in a specific folder in the PC as an .xml file. Aggregation Server Generator recognizes each of the .xml files that exist in the folder as assets to be collected and browses the inside of the information. 5 illustrates viewing of modeling information on an asset.

Specifically, key information is extracted to create a client for accessing an asset (target: PLC-equipped manufacturing facility equipped with an OPC UA server). Representative key information for connection and data mapping is as follows.

- NamespaceURL: ID that allows Aggregation Server to identify assets

- EndpointURI: Access information of OPC UA Server with asset information

- Variables: Acquisition of NodeId information, which is an identifier for Variable Types with data

XML modeling files in a specific folder where UANodeSet is saved are read using Java Lib.

3.2 Objectification

3.2.1 Java Architecture for XML Binding (JAXB)

It is a Java API for mutually expressing Java classes and XML, and performs serialization and deserialization between Java classes and XML.

In an embodiment of the present invention, XML is deserialized into Java objects and information in XML is utilized in the form of calling in the form of Java objects and methods. There is no omission of data because XML schema, which is modeling information, is used.

3.2.2 Objectification of UaNodeSet

Objectify using the schema file for UaNodeSet and extract necessary data from modeling information. The schema file is UaNodeSet.xsd and is basically provided by the OPC Foundation.

3.2.3 Extraction of modeling information

As can be seen in Figure 6, the main program called Objects refers to Documents that have modeling information through classes objectified (.java) through JAXB. As shown in Figure 7, by calling a function or variable in a class mapped to JAXB, the main information for accessing the OPC UA Server is extracted, listed, and managed.

As shown in (1) of FIG. 8, prepare for unmarshall by instantiating UANodeSet.class, which is the rootElement of the schema, and map the information in the class obtained through the schema by inserting the modeling information file as shown in (3), (4) UAObject, UAVariable, and UAMethod are extracted from the modeling information.

4. Aggregation Server Generator

4.1 Connection to assets

4.1.1 OPC UA Client creation and connection

OPC UA Client is created and connected through the list object for the OPC UA Server configured through the XML file. Since it accepts multiple assets, OPC UA Server obtained from each XML is created and managed as another object (DeviceSetClass.java).

One DeviceSetClass object contains the following information to create one OPC UA Client.

-ServerEndPointURI

-namespaceURL

-nodeIdList

Clients are created as shown in Figure 9 while executing repetition statements as many as the number of XML imported at first.

4.1.2 Registering MonitoredDataItem

There is also a request/response method in the server/client structure, but in the embodiment of the present invention, a subscription model in which a client can respond whenever a value on the server side changes is used.

In order to use the subscription model, Variable NodeId is required to subscribe to the value, so get the corresponding information from the previously created DeviceSetClass object.

NodeId is a combination of namespaceIndex and id (Example: ns=1;s=myvar). When NodeId is registered in the MonitoredDataItem object, it is passed to the DataChangeListener to call a specific function whenever the value changes.

4.2 OPC UA Server

4.2.1 Create OPC UA Server

OPC UA Server performs the function of Aggregation Server that can collect data of multiple assets. Real-time data generated from OPC UA Clients for each asset is recognized by Variable mapped to Aggregation Server and provided to the top-level Application. As shown in FIG. 10, one OPC UA Server is created.

4.2.2 AddressSpace Configuration and Mapping

Since Aggregation Server is based on the modeling information of imported assets, the basic structure follows the modeling information as it is. In the OPC UA Server configuration process, the Server's AddressSpace can be automatically configured using the UANodeSet-based modeling information XML file.

Use loadModel() function in OPC UA sdk.

Whenever a model is registered one by one, NamespaceURL is automatically assigned to NamespaceIndex. Since NodeId guarantees the identity of Variable, it cannot be duplicated within one AddressSpace, so the Identity of NodeId is guaranteed by NamespaceIndex.

The NamespaceTable of the Server is configured in the same process as shown in FIG. 11, and only the ns value in NodeId is changed to configure Variable.

4.2.3 Reflecting initial and real-time data

It reads the current value of the OPC UA Server of the asset and synchronizes the DataValue of Variable mapped to the Aggregation Server. The DataChangerEvent, which occurs whenever the value changes, is reflected in real-time to the DataValue of the variable mapped to the Aggregation Server.

5. Aggregation Server creation system

12 is a block diagram of an Aggregation Server creation system according to another embodiment of the present invention. As shown, the Aggregation Server creation system according to an embodiment of the present invention includes a communication unit 110, an output unit 120, a processor 130, an input unit 140, and a storage unit 150. can be implemented as a system.

The communication unit 110 is a means for communicating and connecting smart factory assets and upper applications, and the processor 130 creates an aggregation server by the above method to collect information and data of smart factory assets, and to upper applications. to provide.

The input unit 140 receives user commands and transmits them to the processor 130, the output unit 120 is a display on which the execution result of the processor 130 is displayed, and the storage unit 150 functions as a processor 130 and It provides the necessary storage space for operation.

6. Variations

So far, the OPC UA standard information model-based aggregation server generation method and system of smart factory assets have been described in detail with preferred embodiments.

Meanwhile, it goes without saying that the technical spirit of the present invention can also be applied to a computer-readable recording medium containing a computer program for performing the functions of the apparatus and method according to the present embodiment. In addition, technical ideas according to various embodiments of the present invention may be implemented in the form of computer readable codes recorded on a computer readable recording medium. The computer-readable recording medium may be any data storage device that can be read by a computer and store data. For example, the computer-readable recording medium may be ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical disk, hard disk drive, etc., of course. In addition, computer-readable codes or programs stored on a computer-readable recording medium may be transmitted through a network connected between computers.

In addition, although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications are possible by those skilled in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Smart Factory Assets
About UANodeSet-based modeling
OPC UA Server
OPC UA Client
Aggregation Server

Claims (12)

Acquiring, by the Aggregation Server creation system, UANodeSet-based modeling information of smart factory assets from XML files;
Aggregation Server generation system extracting information about smart factory assets from the acquired modeling information;
The Aggregation Server creation system creates OPC UA Clients to connect to OPC UA Servers of smart factory assets; and
The Aggregation Server creation system creates an Aggregation Server that collects data received from OPC UA Servers through OPC UA Clients;
OPC UA Clients,
Subscribe to receive when the data of OPC UA Servers changes,
Steps to create OPC UA Server are:
An Aggregation Server creation method characterized by automatically configuring an AddressSpace of OPC UA Servers using UANodeSet-based modeling information.
The method of claim 1,
The acquisition phase is
An Aggregation Server creation method characterized in that obtaining modeling information of smart factory assets from XML files stored in a specific folder.
The method of claim 1,
The extraction step is
An Aggregation Server creation method characterized by extracting NodeId, which is an identifier for a variable having an ID of a smart factory asset, access information of an OPC UA Server, and data.
The method of claim 3,
The extraction step is
An Aggregation Server creation method characterized in that an XML file is objectified using a schema file for UaNodeSet and necessary information is extracted from modeling information.
The method of claim 4,
The extraction step is
An aggregation server creation method characterized by deserializing an XML file into a Java object and extracting modeling information in the XML file by calling it in the form of a Java object and method.
delete delete The method of claim 1,
The Aggregation Server creation method, characterized in that it further comprises; the step of the Aggregation Server generation system reading the data possessed by the OPC UA Servers and synchronizing the variable data of the Aggregation Server.
The method of claim 8,
Synchronization step,
An Aggregation Server creation method characterized in that it is performed when a DataChangerEvent occurs.
A storage unit in which XML files of UANodeSet-based modeling information of smart factory assets are stored; and
Extract information about smart factory assets from modeling information obtained from XML files stored in the storage unit, create OPC UA Clients to connect to OPC UA Servers of smart factory assets, and OPC through OPC UA Clients A processor that creates an Aggregation Server that collects data received from UA Servers;
OPC UA Clients,
Subscribe to receive when the data of OPC UA Servers changes,
the processor,
An Aggregation Server creation system characterized by automatically configuring the AddressSpace of OPC UA Servers using UANodeSet-based modeling information.
The Aggregation Server creation system creates OPC UA Clients to connect to OPC UA Servers of smart factory assets; and
The Aggregation Server creation system creates an Aggregation Server that collects data received from OPC UA Servers through OPC UA Clients;
OPC UA Clients,
Subscribe to receive when the data of OPC UA Servers changes,
Steps to create OPC UA Server are:
An Aggregation Server creation method characterized by automatically configuring an AddressSpace of OPC UA Servers using UANodeSet-based modeling information.
A communication unit that is communicatively connected to smart factory assets; and
A processor that creates OPC UA Clients to connect to OPC UA Servers of smart factory assets and creates an Aggregation Server that collects data received from OPC UA Servers through OPC UA Clients;
OPC UA Clients,
Subscribe to receive when the data of OPC UA Servers changes,
the processor,
An Aggregation Server creation system characterized by automatically configuring the AddressSpace of OPC UA Servers using UANodeSet-based modeling information.

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