A production information objectification modeling method based on an OPC UA protocol

Abstract

The application provides a production information objectification modeling method based on an OPC UA protocol. The method is based on the OPC UA protocol to realize a unified architecture according to actual requirements of an application scene, connect production line equipment and an information management system, standardize an abstract model and a description language of processing equipment, and define model attributes of the production line equipment; based on an objectification modeling idea, the processing equipment is modeled one by one, and an objectified information model is connected and established, and a digital model of an entity equipment is realized, so that the influence of information islands is eliminated, interconnection between devices is realized, and production information can be better counted and managed.

Description

Technical Field

[0001] This invention relates to the field of production information modeling technology in manufacturing production lines, and specifically to an object-oriented modeling method for production information based on the OPC UA protocol. Background Technology

[0002] With the development of Industry 4.0, the manufacturing industry is increasingly emphasizing the development of IoT technology and the construction of smart factories, and information modeling is the foundation of these new technologies. However, in actual production workshops, the heterogeneity and semantic complexity of equipment from different manufacturers often make it difficult for models to interact. To address this issue, the OPC UA protocol can effectively control this impact. However, the lack of a complete modeling method and process based on the OPC UA protocol still exists.

[0003] Furthermore, traditional production information modeling focuses only on individual devices, leading to unclear relationships between production line data and the creation of information silos. When anomalies occur in certain data, it's difficult to determine the upstream and downstream connections. Additionally, collecting production information from the entire production line typically relies on device models integrated into the monitoring and management system, rather than a complete production line information model. This increases the burden on the system's data processing, raises the manpower costs of production line management, and negatively impacts production efficiency and profitability. Summary of the Invention

[0004] The purpose of this invention is to provide a production information object-oriented modeling method based on the OPC UA protocol to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A production information object-oriented modeling method based on the OPC UA protocol includes the following steps:

[0007] Step 1: Based on the OPC UA protocol, analyze the application scenarios, clarify the network infrastructure and environment, and establish a unified communication architecture in combination with actual production needs.

[0008] Step 2: Compile production information based on the actual production line and equipment manuals, and install sensors on equipment that cannot collect data in order to collect the necessary modeling data more comprehensively;

[0009] Step 3: Based on object-oriented principles, classify the collected production information and determine the relationships or generalizations between the information. Then, based on the collected production information, establish object models, dynamic models, and functional models of the production line.

[0010] Step 4: Based on the OPC UA protocol, the object model is transformed into an information model that conforms to the protocol requirements, and the information model is transformed into a data file that can be identified, stored, and modified in the digital space. A production management system is then developed to facilitate the collection and management of data during the production process.

[0011] The unified architecture in step 1 provides synchronous, asynchronous, or distributed communication mechanisms, allowing for horizontal or vertical data access and flexible setting of read and write permissions.

[0012] The production information extracted in step 2 includes the static attribute set and the dynamic attribute set of the production line equipment. The static attribute set is a collection of static attribute data for the processing equipment. Static data refers to information on the equipment that will not change or whose changes will not affect the final production result, such as equipment number, name, and category, reflecting the inherent attributes of the equipment. The dynamic attribute set is data collected throughout the entire production process that may change as production progresses, such as machine tool spindle speed, main control cabinet operating program, and the equipment's operating status and component switching status that describe the production process. If new sensors need to be installed, the installed sensors should conform to the OPC UA functional architecture.

[0013] The specific implementation steps in step 3 are as follows:

[0014] Step 3.1 After analysis, the collected production information is divided into three categories: object, dynamic, and function, and the relationships between the information are determined.

[0015] Step 3.2 Construct the object model. First, determine the basic information of the equipment, such as its number and name; then determine the processing sequence and processing technology between the equipment.

[0016] Step 3.3 Construct a dynamic model, considering parameters that change sequentially over time under control actions. The dynamic model can reflect the processing status of the equipment and the processing status of the product.

[0017] Step 3.4 Construct a functional model to reflect the changes in data under control, and to show the relationships and functions between the values;

[0018] Step 3.5 involves systematically organizing the established object-oriented model. This systematic organization refers to adjusting the already modeled object-oriented model (including object model, dynamic model, and functional model) based on actual needs. The specific adjustments are made according to actual needs and operating conditions, as those skilled in the art will understand.

[0019] The classification criteria are as follows: Object information includes the work objects of the production line system, the relationships between objects, the attributes of objects in the identifier class, and the static structure of the operation table organizing the system; dynamic information includes information that changes according to time and operation sequence; functional information includes the data types generated by the equipment, the sequential execution of operations, and changes in the completed values. Regarding the relationships between information, association describes the combination of links with common structure and common semantics; generalization describes the relationship between a class and extracting one or more versions of that class.

[0020] In step 4, the object-oriented model is converted into an information model that conforms to the OPC UA protocol. The information model should include the following three elements:

[0021] 1) Basic nodes, including: object, object type, variable, variable type, data type, reference type, method, and view;

[0022] 2) Type definition defines the attributes, structure, and semantics of a node instance. Subtypes within a node can be freely defined to exist based on the actual application.

[0023] 3) Reference types are directed connections between two nodes in the model, allowing a node to be directly or indirectly connected to the root node.

[0024] For easy reference.

[0025] The information model can be converted into an XML file using XML schema, and a system for data statistics and management of production line information can be developed. When performing data statistics and management of production line information, if the information model of the processing equipment changes and the requirements are updated, only the corresponding elements of the XML file need to be modified.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention employs an object-oriented modeling method for production information based on the OPC UA protocol. Compared to traditional production information modeling methods, OPC UA provides a unified information model that can describe and represent various equipment, resources, and processes in manufacturing. This unified information model helps enterprises better understand and describe their manufacturing processes and supports more flexible and efficient production operations and management. Furthermore, considering future upgrades and modifications to production lines, OPC UA supports multiple communication protocols and network technologies, including Ethernet, wireless networks, and cloud platforms. This allows enterprises to choose the appropriate communication method according to their needs and easily expand and integrate new equipment and systems.

[0028] Furthermore, object-oriented modeling technology, while centralizing production information across the entire production line, can divide the information model into three main types—object, dynamic, and functional—based on the different needs of manufacturers. This more efficiently represents the relationships between data and reduces the difficulty of identifying data anomalies. It also improves the accuracy and real-time performance of production data. This helps production managers better monitor the production process, promptly identify anomalies, and take appropriate measures, thereby improving product quality and production efficiency.

[0029] In summary, this invention can improve production efficiency, enhance information sharing and integration, improve data accuracy and real-time performance, reduce the pressure on system data processing, reduce labor costs, and thus improve the production efficiency and competitiveness of the entire manufacturing industry. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the basic implementation framework of the present invention;

[0031] Figure 2 The functional architecture for OPC UA services is as follows:

[0032] Figure 3 Schematic diagram of object-oriented modeling for impeller production line

[0033] Figure 4 Impeller production line information modeling scheme diagram Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0035] like Figures 1 to 4 As shown, this example illustrates a production information object-oriented modeling method based on the OPC UA protocol, combined with... Figure 1 This includes the following steps:

[0036] Step 1: Based on the OPC UA protocol, analyze the application scenarios, clarify the network infrastructure and environment, and establish a unified communication architecture in combination with actual production needs.

[0037] Step 2: Compile production information based on the actual production line and equipment manuals, and install sensors on equipment that cannot collect data in order to collect the necessary modeling data more comprehensively;

[0038] Step 3: Based on object-oriented thinking, classify the collected production information and determine the correlation or generalization relationship of the information. Then, establish the object model, dynamic model and functional model of the production line based on the collected production information.

[0039] Step 4: Based on the OPC UA protocol, the object model is transformed into an information model that conforms to the protocol requirements, and the information model is transformed into a data file that can be identified, stored, and modified in the digital space. A production management system is then developed to facilitate the collection and management of data during the production process.

[0040] In a preferred embodiment, step 1 involves analyzing application scenarios based on the OPC UA protocol, clarifying network infrastructure and environmental factors, and establishing a unified communication architecture in conjunction with actual production needs. The specific implementation steps are as follows:

[0041] 1) System analysis of application scenarios: The system built in this example needs to be applied to field-level bridging of different production components, office area monitoring and control of production, and remote operation across network segments;

[0042] 2) Set read and write permissions for different operations. For example, the monitoring function in this example only requires read permission and not write permission. Setting read and write permissions reasonably can reduce the impact on the production process and the threat to network security.

[0043] 3) Building such Figure 2 The OPC UA unified communication architecture is shown.

[0044] In a preferred embodiment, step 2 involves compiling production information based on the actual production line and equipment manuals, and simultaneously installing sensors on equipment that cannot collect data, in order to collect the necessary modeling data more comprehensively. The specific implementation steps are as follows:

[0045] 1) Based on actual production needs, collect relevant industry standards and specifications, summarize relevant data, obtain modeling requirements, determine processing flow and technology, and conduct actual inspections of the production line to determine whether the required data can be collected according to the OPC UA protocol.

[0046] This example demonstrates the production requirements for functions such as collecting workpiece information in the production workshop, calculating and estimating product defect rates, managing workshop production information, and monitoring the working status of the machining center.

[0047] Its main function is to establish an information model of the production process based on the production plan, combined with the processing parameters and machine tool operation procedures in the production process, by measuring energy consumption output indicators and equipment stable operation parameters, so as to improve production efficiency and product quality, as shown in Table 1-1 below;

[0048] Table 1-1 Requirements Analysis for Production Process Information Model

[0049]

[0050]

[0051] 2) Install sensors that conform to the OPC UA functional architecture on devices that need but cannot collect data;

[0052] In a preferred embodiment, step 3 is based on object-oriented principles, classifying the collected production information and determining the relationships or generalizations between the information. Then, based on the collected production information, an object model, dynamic model, and functional model of the production line are established. The specific implementation steps are as follows:

[0053] 1) After analysis, the collected production information is divided into three categories: object, dynamic, and function, and the relationships between the information are determined;

[0054] 2) Construct the object model. The object model represents the static data structure of the objective system. It describes the fixed attributes or attributes that change very little of the production equipment. When constructing the object model, first determine the basic information of the equipment, such as its number and name; then determine the processing sequence and processing technology between the equipment.

[0055] 3) Construct a dynamic model, considering the parameters that change sequentially over time under control actions. The dynamic model can reflect the processing status of the equipment and the processing status of the product.

[0056] 4) Construct a functional model to reflect the changes in data under control, and to show the relationships and functions between the values;

[0057] 5) Systematically organize the constructed object-oriented model, combining... Figure 3 Based on actual production needs, this example horizontally divides the established impeller production line object model into three categories: personnel situation, processing situation, and scenario interaction.

[0058] In the preferred example, combined Figure 4 Step 4, based on the OPC UA protocol, transforms the object-oriented model into an information model that conforms to the protocol requirements, and then transforms the information model into a data file that can be identified, stored, and modified in the digital space. A production management system is then developed to facilitate the statistical analysis and management of data during the production process. The implementation steps are as follows:

[0059] 1) Based on the object model established in step 3, define nodes, types and reference types in the context of the OPC UA protocol, and transform the object model into an OPC UA information model using the modeling tool Ua Modeler;

[0060] 2) A modeling tool such as Ua Modeler can be used to convert the information model in XML mode into an XML data file that can be recognized, stored, and modified in the digital space;

[0061] 3) Parse the XML description file using Open62541SDK and Python tools and map it to the OPC UA server address space;

[0062] 4) The system reads the server address space through the client tool Ua Expert, displays the information model content, loads and browses the information model, and implements data statistics and management of production line information;

[0063] In a preferred embodiment, step 4 utilizes the unified standardization, scalability, and cross-platform / cross-system characteristics of XML description files. OPC UA information models are typically loaded using XML description files. However, writing XML description files requires pure code, which is labor-intensive. Therefore, node information can be quickly created using all the standard nodes built into the modeling tool Ua Modeler. This node information can be updated during subsequent equipment replacements and upgrades. After modeling is complete, Ua Modeler automatically generates the corresponding XML file for reference. When performing data statistics and management of production line information, if the information model of the processing equipment changes and requirements are updated, only the corresponding elements of the XML file need to be modified.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the present invention without departing from its novel spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A production information object-oriented modeling method based on the OPC UA protocol, characterized in that, Includes the following steps: Step 1: Based on the OPC UA protocol, analyze the application scenarios, clarify the network infrastructure and environmental factors, and establish a unified communication architecture in combination with actual production needs; Step 2: Compile production information based on the actual production line and equipment manuals, and install sensors on equipment that cannot collect data in order to collect the necessary modeling data more comprehensively; Step 3: Based on object-oriented thinking, classify the collected production information and determine the correlation or generalization relationship of the information. Then, establish an object-oriented model based on the collected production information, including the object model, dynamic model and functional model of the production line. Step 4: Based on the OPC UA protocol, the object model is transformed into an information model that conforms to the protocol requirements, and the information model is transformed into a data file that can be identified, stored, and modified in the digital space. A production management system is then developed to facilitate the collection and management of data during the production process.

2. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: The unified communication architecture in step 1 provides synchronous, asynchronous, or distributed communication mechanisms, allowing horizontal or vertical access to data and flexible setting of read and write permissions.

3. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: The production information to be extracted in step 2 includes the static attribute set and dynamic attribute set of the production line equipment: The static attribute set is a collection of static attribute data of the processing equipment. Static data refers to information on the equipment that will not change or whose changes will not affect the final result of actual production. It includes number, name, and category information, reflecting the inherent attributes of the equipment. The dynamic attribute set is data collected throughout the entire production process of the production line that may change as the production process progresses. It includes machine tool spindle speed, main control cabinet operating program information, and equipment production operation status and component switching status that can describe the production and processing process.

4. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1 is characterized in that: The sensor installed in step 2 should conform to the OPC UA functional architecture.

5. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: The specific implementation steps in step 3 are as follows: 1) After analysis, the collected production information is divided into three categories: object, dynamic, and function, and the relationships between the information are determined; 2) Construct an object model. First, determine the basic information of the equipment, such as its number and name; then determine the processing sequence and processing technology between the equipment. 3) Construct a dynamic model, considering parameters that change sequentially over time under control actions. The dynamic model can reflect the processing status of the equipment and the processing status of the product. 4) Construct a functional model to reflect the changes in data under control, and to show the relationships and functions between the values; 5) Systematically organize the established object-oriented model.

6. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: The information classification criteria based on object-oriented thinking in step 3 are as follows: object information includes the work objects of the production line system, the relationships between objects, the attributes of objects in the identifier class, and the static structure of the operation table organizing system; dynamic information includes information that changes according to time and operation sequence; and functional information includes the data types generated by the equipment, the sequential execution of operations, and the changes in the completed values.

7. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: In step 3, the criteria for determining information relationships are: association describes a combination of links that have a common structure and shared semantics; generalization describes the relationship between a class and one or more versions of that class.

8. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: In step 4, the object-oriented model is converted into an information model that conforms to the OPC UA protocol. The information model should include the following three elements: 1) Basic nodes, including: object, object type, variable, variable type, data type, reference type, method, and view; 2) Type definition defines the attributes, structure, and semantics of a node instance; the existence of subtypes within a node is freely defined based on the actual application. 3) Reference type is a directed connection between two nodes in the model, which connects the node directly or indirectly to the root node, making it easier to query.

9. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: In step 4, the information model is converted into an XML file based on the OPC UA protocol, and a system for data statistics and management of production line information is developed.

10. The production information object-oriented modeling method based on the OPC UA protocol according to claim 1, characterized in that: When performing data statistics and management of production line information, if the information model of the processing equipment changes and the requirements are updated, only the corresponding elements of the XML file need to be modified.

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