Maintenance process modeling system based on ontology and meta-model

Abstract

The invention discloses a maintenance process modeling system based on an ontology and a meta-model, and belongs to the technical field of maintenance, and the system comprises an ontology construction module which is used for constructing an application ontology oriented to a maintenance process; the meta-model construction module is used for constructing a maintenance process meta-model based on the SysML constructive form according to the application ontology; the maintenance process construction module is used for establishing an application instance maintenance process model by adopting SysML based on the meta-model; and the evaluation and output module is used for carrying out ontology reasoning on a maintenance process instance by adopting Protege based on the application ontology, verifying the reasonability of a maintenance process model and outputting a result. The invention provides an efficient and normalized maintenance process modeling system, and fusion of maintainability design analysis and system design analysis can be promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of maintenance, more particularly to a maintenance process modeling system based on ontology and meta-model. BACKGROUND

[0002] Maintenance is all activities for keeping, restoring or improving the specified technical state of equipment, and the maintenance process refers to the process of changing the state of the object into the target state due to the continuous advancement of the above activities, which is a typical discrete event process. GJB145A-2006 defines the relationship model of maintenance process and related maintenance activities, including serial operation model, parallel operation model, network operation model, etc., and points out the maintenance process model that can be established under different relationships of maintenance activities.

[0003] Currently, the maintenance process modeling at home and abroad mainly focuses on petri net modeling. Chen Chunliang et al. established the equipment maintenance process library / transformation net model and colored time Petri net model to solve the problems of low equipment maintenance efficiency and lack of process control, and gave the description of dynamic, random and time of equipment maintenance process. Liu Jiaxue et al. proposed a process modeling method combining Petri net and semantic network to solve the problems of large model, non-repetitive maintenance process and chaotic description of relationships between components in virtual maintenance process. Wang Feizhang et al. established a virtual maintenance process modeling method based on colored Petri net to express maintenance resource model and describe various logical relationships between maintenance operations, and gave the general modeling steps. Qian Wenhua et al. proposed a Petri net airplane virtual maintenance process modeling method with dynamic recombination of subnets to solve the problems of numerous components, complex maintenance behavior relationships and large model in virtual maintenance simulation of large civil aircraft. Zhang et al. modeled the maintenance process based on Petri net, incorporated the selected tests into the maintenance process, and used discrete event simulation for analysis to predict the expected completion time distribution. Li et al. used the process modeling method based on Petri net to describe the actual maintenance process, and through the use of this method, the performance indicators of the maintenance process can be obtained.

[0004] In recent years, the Model-Based Systems Engineering (MBSE) method has become an important method and tool in the process of power / performance design of national defense equipment. The MBSE method provides a new way of thinking and means for the design and optimization of complex systems by supporting the forward research and development process from requirement definition, function analysis, logical design to physical design and comprehensive verification. The Petri net method cannot match the current design process based on MBSE in product maintainability design. Some scholars apply MBSE and knowledge engineering methods to the modeling of maintenance process to support the maintainability design process. For example, Qiu et al. established a maintenance process knowledge metadata model, which can effectively describe the maintenance process characteristics, maintenance resources, maintenance process work instructions and maintenance quality control, and developed an expression of aircraft maintenance process knowledge using XML technology; Huang et al. focused on the problem of disassembly and assembly of parts in the same scene in the study of collaborative virtual maintenance process, and proposed an interactive state machine model for aircraft collaborative virtual maintenance process, which established a state transition model for maintenance personnel and operating objects by using UML state machine; Geng et al. proposed a virtual maintenance process modeling method based on meta-model fusion to reduce the complexity of the aircraft virtual maintenance process model, defined the maintenance object meta-model using SysML state machine, reused the meta-model that meets the assembly relationship to express the same maintenance sequence, and thus reduced the number of model nodes and the complexity of the model. However, the above methods have different focuses and still have some shortcomings, which are as follows:

[0005] (1) The related knowledge of maintenance process is lack of sorting and summary. The current modeling methods of maintenance process have significant shortcomings in the systematic sorting and summary of related knowledge. The existing modeling of maintenance process has different focuses and lacks comprehensiveness. Maintenance process involves various activities and resources, covering multiple links from technical state analysis to actual operation. The lack of systematic knowledge system makes it difficult to accurately express various characteristics and logical relationships of maintenance process in the modeling process.

[0006] (2) The existing modeling methods do not widely use system modeling language, and lack standardized representation and application. Although the current Petri net modeling method has certain advantages in expressing the dynamic nature and logical relationship of maintenance process, it still has shortcomings in the application of system modeling language, which limits the effective analysis of maintenance process and maintainability design in the product design process, and it is difficult to form effective reference and guidance. To better adapt to the MBSE framework, maintenance process modeling needs to widely use system modeling language, so that the model can be seamlessly integrated between different design stages and teams, thereby improving the collaborative efficiency and decision-making quality of the design process.

[0007] Therefore, how to provide an ontology and meta-model based maintenance process modeling system is an urgent problem for those skilled in the art. SUMMARY

[0008] Therefore, the application provides an ontology and meta-model based maintenance process modeling system to normalize representation and application of maintenance process models and provide effective reference for maintenance design.

[0009] To achieve the above object, the application provides the following technical scheme.

[0010] An ontology and meta-model based maintenance process modeling system comprises:

[0011] An ontology construction module: constructs an application ontology for maintenance process;

[0012] A meta-model construction module: constructs a maintenance process meta-model based on SysML according to the application ontology;

[0013] A maintenance process construction module: establishes an application instance maintenance process model using SysML based on the meta-model;

[0014] An evaluation and output module: performs ontology reasoning of maintenance process instance using Protégé based on the application ontology, verifies rationality of the maintenance process model, and outputs results.

[0015] Further, the ontology construction module comprises:

[0016] An analysis expression model construction unit: establishes an analysis expression model of maintenance process knowledge concept;

[0017] An element extraction unit: analyzes maintenance process maintenance knowledge elements through the analysis expression model of maintenance process knowledge concept;

[0018] An ontology construction unit: constructs an application ontology for maintenance process based on the maintenance process maintenance knowledge elements;

[0019] A visual display unit: visually displays the constructed application ontology.

[0020] Further, the meta-model construction module comprises:

[0021] An element relationship analysis unit: analyzes relationships between maintenance process maintenance knowledge elements and constructs a systematic maintenance framework;

[0022] A meta-model construction unit: performs formal modeling of maintenance process maintenance knowledge elements and relationships between the maintenance process maintenance knowledge elements using SysML.

[0023] Further, the maintenance process construction module comprises:

[0024] a classification and modeling unit, which classifies the maintenance processes and models the classified maintenance processes based on the meta-model;

[0025] a complete modeling unit, which models the complete maintenance process.

[0026] Further, the evaluation and output module comprises:

[0027] a rule establishing unit, which establishes Protégé maintenance process ontology reasoning rules;

[0028] an evaluation unit, which performs reasoning verification on the established maintenance process model based on the reasoning rules;

[0029] an output unit, which outputs the reasoning verification result.

[0030] Further, the rule establishing unit, which establishes Protégé maintenance process ontology reasoning rules, comprises:

[0031] tool requirement reasoning rules, maintenance equipment requirement reasoning rules, maintenance criterion transmission reasoning rules, maintenance work step transmission reasoning rules, maintenance resource transmission reasoning rules and maintenance personnel reasoning rules.

[0032] According to the technical solution, compared with the prior art, the maintenance process modeling system based on ontology and meta-model is provided, which can provide effective reference for maintenance design by combining ontology, meta-model, SysML system modeling language and other methods to standardize representation and application of the maintenance process model. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0034] Figure 1 a maintenance process modeling system detail architecture diagram provided by the present application;

[0035] Figure 2 a maintenance process modeling system overall structure schematic diagram provided by the present application;

[0036] Figure 3 a maintenance process knowledge concept expression schematic diagram;

[0037] Figure 4 a maintenance process application ontology schematic diagram constructed by Protégé.

[0038] Figure 5 SysML stereotype diagram for maintenance process meta-model construction;

[0039] Figure 6(1) installation process model diagram;

[0040] Figure 6(2) disassembly process model diagram;

[0041] Figure 6(3) plug safety process model diagram;

[0042] Figure 6(4) welding process model diagram;

[0043] Figure 6(5) crimping process model diagram;

[0044] Figure 6(6) insulation stripping process model diagram;

[0045] Figure 6(7) sealing process model diagram;

[0046] Figure 6(8) handling process model diagram;

[0047] Figure 7 Maintenance process model diagram constructed by SysML stereotype and activity diagram;

[0048] Figure 8 Ontology inference and verification diagram for maintenance process instance by Protégé. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0050] The application aims to provide a maintenance process modeling system based on ontology and meta-model, comprising an ontology construction module, a meta-model construction module, a maintenance process construction module, and an evaluation and output module; specifically, the application ontology oriented to the maintenance process is constructed through the modules, the maintenance process knowledge concept analysis expression model is established, the product maintenance information of the maintenance is expressed, the concepts, attributes and relationships existing in the maintenance process maintenance domain are further analyzed, the entities, object attributes and data attributes of the maintenance process ontology concept (class) are constructed in Protégé, and the ontology visualization construction is completed. Based on the application ontology, the maintenance process meta-model is divided into eight blocks: maintenance process, maintenance step, maintenance object, maintenance equipment, maintenance tool, maintenance personnel, maintenance resource and maintenance criterion. The eight elements in the maintenance process meta-model are correlated with each other and jointly constitute a systematic maintenance framework: the maintenance process is composed of multiple maintenance steps, each step is specifically operated on the maintenance object, and the task is completed with the help of the maintenance equipment and the maintenance tool. The maintenance personnel executes the step according to the maintenance criterion, ensures the safe and effective operation, and uses the maintenance resource to ensure the smooth progress of the maintenance process. The organic combination of these elements ensures the integrity and standardization of the maintenance process, and realizes the effective maintenance and repair of the equipment or system. Meanwhile, according to the maintenance process application ontology, the relationship between the meta-models is expanded, six types of relationship meta-models, i.e. execution, need, compliance, inclusion, action on and guarantee, are expanded, and the maintenance process meta-model is constructed by using the SysML construction type. Based on the meta-model, eight types of typical product maintenance process models, such as installation, disassembly, insurance, welding, clamping, insulation stripping, sealing and transportation, are established. Based on the modeling form of the typical maintenance process, the complete maintenance process is modeled by using the eight types of object construction types, i.e. maintenance process, maintenance step, maintenance object, maintenance equipment, maintenance tool, maintenance personnel, maintenance resource and maintenance criterion, and the six types of relationship construction types, i.e. execution, need, compliance, inclusion, action on and guarantee, to model the installation (example) maintenance process of the machine case body. Based on the ontology and the established maintenance process model, the maintenance process ontology reasoning verification is performed by using Protégé, six types of reasoning types, i.e. tool demand reasoning, maintenance equipment demand reasoning, maintenance criterion transmission reasoning, maintenance step transmission reasoning, maintenance resource transmission reasoning and maintenance personnel reasoning, are formulated, a solution for the standardized representation and application of the maintenance process model is provided, and an effective reference for the maintainability design is provided.

[0051] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0052] As shown in Figures 1-2 , the embodiment of the application discloses a maintenance process modeling system based on ontology and meta-model, comprising:

[0053] The ontology construction module constructs the application ontology oriented to the maintenance process;

[0054] A meta-model construction module constructs a maintenance process meta-model based on SysML modeling according to the application ontology;

[0055] A maintenance process construction module establishes an application instance maintenance process model using SysML based on the meta-model;

[0056] An evaluation and output module performs ontology reasoning of the maintenance process instance using Protégé based on the application ontology, verifies the rationality of the maintenance process model, and outputs the result.

[0057] Specifically, the application provides an efficient and standardized maintenance process modeling system, which can promote the integration of maintainability design analysis and system design analysis.

[0058] In one specific embodiment, the ontology construction module can provide a structured and standardized representation of the maintenance process for the application ontology of the maintenance process, identify the concepts, attributes and relationships existing in the maintenance domain, enhance the expressiveness and accuracy of the maintenance process model, and provide more efficient and intelligent support for the maintenance and maintenance of complex systems.

[0059] Specifically, the ontology construction module includes:

[0060] An analysis expression model construction unit establishes a maintenance process knowledge concept analysis expression model;

[0061] An element extraction unit analyzes maintenance process maintenance knowledge elements through the maintenance process knowledge concept analysis expression model;

[0062] An ontology construction unit constructs an application ontology for the maintenance process based on the maintenance process maintenance knowledge elements;

[0063] A visual display unit visually displays the constructed application ontology.

[0064] Specifically, in order to clearly express the related concepts of the maintenance process, a maintenance process knowledge concept analysis expression model is proposed as shown on the left side. Figure 3 The maintenance process knowledge concept analysis expression model mainly focuses on expressing the knowledge content contained in the maintenance information involved in the maintenance process. In the maintenance aspect, the maintenance object part repair process information, maintenance equipment layout, and related operators and equipment involved in the maintenance process are expressed.

[0065] Firstly, the product maintenance information is expressed, which mainly includes maintenance process information for different failure modes, including maintenance procedures, maintenance steps, etc. Then, for different maintenance procedures, the maintenance equipment used in different procedures and the sequence relationship of the maintenance equipment are expressed. Finally, the related entity information of the maintenance process is expressed, such as maintenance equipment, maintenance tools, maintenance parts, maintenance personnel, etc.

[0066] The maintenance process knowledge concept analysis and expression model has good adaptability. When the product type changes, the newly added factors are classified and analyzed through the concept analysis model, and the elements expressed in the model are changed in the corresponding position, so that the model can be updated without the need to redesign the overall model architecture. For example, when a structure in the system changes or a test equipment is adjusted or replaced, a corresponding concept can be created in the model, related maintenance process knowledge concepts are added or deleted, and the link relationship between the concepts is updated to complete the update of the maintenance process knowledge concept analysis and expression model. The model can improve the flexibility of maintenance process knowledge expression, help knowledge engineers more accurately analyze and obtain the concepts and data involved in the field, and effectively help to sort out the maintenance process knowledge concepts, attributes and relationship definitions and construct the ontology.

[0067] Through the maintenance process knowledge concept analysis and expression model, the concepts, attributes and relationships in the maintenance domain of the maintenance process are further analyzed. Concept attributes refer to the set of attributes of each concept in the concept set, which are used to describe the characteristics of the concept. The relationship between concepts in the ontology depends on the relationship between entities, which can describe the framework of the maintenance process knowledge. The commonly used knowledge relationships in ontology construction mainly include the following four kinds: Kind_of (kind of), Part_of (part of), Attribute_of (attribute of), and Subclass_of (subclass of). In actual construction, in addition to the above four relationships, the relationship between knowledge concepts can be defined according to the actual needs of the field. The maintenance process maintenance knowledge elements mainly include eight kinds of concepts such as maintenance procedures, maintenance steps, maintenance objects, maintenance equipment, maintenance tools, maintenance personnel, maintenance resources, and maintenance criteria, as shown in Table 1.

[0068] Table 1 Maintenance process related knowledge concepts

[0069]

[0070] After the maintenance related concepts of the maintenance process are defined, the relationship between the concepts needs to be defined. According to the consultation of system related maintenance manuals, maintenance work cards, etc., after consulting professional knowledge engineers, 10 types of relationships between maintenance related concepts of the maintenance process are determined, as shown in Table 2.

[0071] Table 2 Relationships between maintenance process related knowledge concepts

[0072] Serial number Conceptual relationship type Paraphrase Inverse relationship 1 SubClass_of Parent-child relationship / 2 Part_of Whole-part relationship / 3 ServiceFor Service for / 4 Use Use / 5 BasedOn Based on / 6 AbrideBy Abide by / 7 Attribute_of Attribute relationship / 8 Excute Execute / 9 ActOn Act on / 10 Support Figure 3 /

[0073] According to the maintenance-related concepts, attributes and relationships of the maintenance process defined above, the maintenance-related knowledge concepts of the maintenance process knowledge and their semantic relationships are expressed, such as Figure 4 as shown on the right side.

[0074] The visual display unit: apply the ontology visualization, as follows:

[0075] Entity construction of the maintenance process ontology concept (class):

[0076] Concept (class) is the most important entity type in the ontology. According to the design of the maintenance process ontology described above, the class concept set of the maintenance process ontology is constructed, and the class hierarchy relationship is constructed in combination with the class hierarchy.

[0077] Object property construction of the maintenance process ontology:

[0078] There are interactive relationships between classes and terms. In Protégé, relationships are expressed by defining object properties. The establishment of object properties is carried out in Objectproperties. For each rule, the definition domain and value domain of the property are given. For example, for the "Eliminate" property, the "maintenance process" and "fault mode" entities are connected, that is, "maintenance process" "Eliminate" "fault mode".

[0079] Data property construction of the maintenance process ontology:

[0080] After the establishment of the class, the data properties of the class, that is, the values of the properties of the above-mentioned class, are given in Dataproperties. In addition, it needs to be noted that the data properties of the entity are indicated. For example, "maintenance process" has "ProcessID" data property, which belongs to "xsd: String".

[0081] After class, object property and data property, the established ontology is visualized by OntoGraf, as shown in Extension element . By constructing the maintenance process application ontology, the construction and expression of the maintenance process meta-model can also be discussed.

[0082] In a specific embodiment, the meta-model construction module comprises:

[0083] The element relationship analysis unit analyzes the relationships between the maintenance process maintenance knowledge elements, and constructs a systematic maintenance framework;

[0084] The meta-model construction unit uses SysML stereotypes to formally model the maintenance process maintenance knowledge elements and the relationships between the maintenance process maintenance knowledge elements.

[0085] Specifically, the maintenance process meta-model analysis includes:

[0086] A meta-model is a model used to describe models and can be considered as a "model of models". A meta-model defines the elements (such as classes, attributes, methods, relationships, etc.) and their relationships in a model, which can be used to describe the syntax, semantics and constraints of the model. In the field of software development, meta-models are often used to represent data models, process models, business models, etc. in software systems. Meta-models provide a formal representation method that can help designers and developers more accurately and clearly understand and express the structure and semantics of models.

[0087] A meta-model is usually composed of two parts: elements and relationships. Elements are the basic units in a model, usually including classes, attributes, methods, etc., which can establish various relationships with other elements, such as inheritance, association, aggregation, etc. Relationships describe the connections and dependencies between elements, including dependency relationships, association relationships, inheritance relationships, etc. Elements and relationships together constitute a meta-model, describing the concepts, attributes and behaviors in the model.

[0088] As a tool for describing abstract models in a specific domain, a meta-model is an abstraction of entities, attributes, relationships, operations, etc. in the field of study to facilitate systematic description, analysis and design. Meta-models can be used to build other models, specifications, standards and tools, etc. so that better coordination and consistency can be achieved in all aspects of the field. Establishing a meta-model is an iterative process that requires continuous information collection and feedback, and the meta-model needs to be continuously improved and optimized.

[0089] The establishment process of the maintenance process model mainly depends on the related elements involved in the maintenance process, and assumes the virtual maintenance environment as the maintenance environment, describes each element to obtain the maintenance process model. Finally, the description of a certain maintenance action in the virtual maintenance environment is completed by filling in the maintenance process model.

[0090] According to the application ontology of maintenance process, the maintenance process meta-model is divided into eight parts: maintenance process, maintenance step, maintenance object, maintenance equipment, maintenance tool, maintenance personnel, maintenance resource and maintenance criterion. The eight elements in the maintenance process meta-model are interrelated and together form a systematic maintenance framework: a maintenance process is composed of multiple maintenance steps, each step is performed on a maintenance object, and the task is completed with the help of maintenance equipment and maintenance tools. Maintenance personnel perform the steps according to the maintenance criterion to ensure safe and effective operation, and maintenance resources are used to ensure the smooth progress of the maintenance process. The organic combination of these elements ensures the integrity and standardization of the maintenance process, and achieves effective maintenance and repair of equipment or systems.

[0091] At the same time, according to the application ontology of maintenance process, the relationship between meta-models is expanded, and a total of six categories are expanded, as shown in Table 3.

[0092] Table 3 Relationship between maintenance process meta-models

[0093]

[0094] Based on the SysML stereotype, the maintenance process meta-model is modeled:

[0095] The SysML stereotype is used to establish eight types of objects: maintenance process, maintenance step, maintenance object, maintenance equipment, maintenance tool, maintenance personnel, maintenance resource and maintenance criterion, as well as six types of relationship meta-models: execution, need, comply, contain, act on and guarantee. In SysML, the expansion of meta-models requires the existence of base classes. Maintenance personnel are a description of maintenance operators, so the Actor base class in the block definition diagram is selected for expansion modeling. Since maintenance objects, maintenance equipment, maintenance tools, maintenance resources and maintenance criteria are descriptions of objective things, block diagrams can describe the attributes and functions of blocks, and the main advantage of block diagrams is that they can provide formalized descriptions of each part of a system and its interactions, which helps with system design and analysis, so block diagrams are selected for expansion of operating objects and operating tools; maintenance process and maintenance step are dynamic behavior processes themselves, which can be expanded based on the Activity and Action base classes in the activity diagram, used for expansion modeling of maintenance operations, and the expansion of the remaining relationships is selected according to actual needs. The expansion base classes and descriptions corresponding to the final maintenance process meta-model are shown in Table 4.

[0096] Table 4 Expansion base classes of maintenance process meta-model

[0097] Extension base class Maintenance process Profile: Maintenance process UMUML4SysML: Activity Maintenance process Profile: Maintenance step UML4SysML: Action Maintenance process Profile: Maintenance object UML4SysML: Object Maintenance process Profile: Maintenance equipment UML4SysML: Block Maintenance process Profile: Maintenance tool UML4SysML: Block Maintenance process Profile: Maintenance personnel UML4SysML: Actor Maintenance process Profile: Maintenance resource UML4SysML: Block Maintenance process Profile: Maintenance criterion UML4SysML: Block Maintenance process Profile: Execute UML4SysML: Connector Maintenance process Profile: Need UML4SysML: Dependency Maintenance process Profile: Abide by UML4SysML: Dependency Maintenance process Profile: Include UML4SysML: Include Maintenance process Profile: Act on UML4SysML: Connector Maintenance process Profile: Guarantee UML4SysML: Connector Figure 5

[0098] A profile is a package in SysML, which is usually defined by extending the core UML, SysML object types, adding new stereotypes and metaclasses in the profile, defining stereotype internal value properties, adding enumeration types to stereotypes, creating tagged value types from predefined types, defining structured tagged values, predefined structured types, defining tagged groups, and the like. Figure 7 For the maintenance process profile, eight object stereotype types, i.e., maintenance process, maintenance step, maintenance object, maintenance equipment, maintenance tool, maintenance personnel, maintenance resource, and maintenance criterion, and six relationship stereotype types, i.e., execution, need, comply, contain, act on, and guarantee, are defined in the profile, and three enumeration types, i.e., maintenance equipment type, maintenance tool type, and maintenance personnel level, are added to the maintenance equipment, maintenance tool, and maintenance personnel stereotype types.

[0099] In one embodiment, based on the above-established maintenance process stereotype, the maintenance process construction module includes:

[0100] The classification and modeling unit classifies the maintenance processes and models the classified maintenance processes based on the meta-model;

[0101] The complete modeling unit models the complete maintenance process.

[0102] Specifically, the typical maintenance process classification and modeling includes:

[0103] The typical product repair process can be mainly divided into eight categories: installation, disassembly, insurance, welding, clamping, insulation stripping, sealing and transportation. Installation refers to assembling, fixing and connecting equipment, components or systems according to design requirements to ensure their normal operation and function, such as installing electrical connectors, installing bolts, installing hoses, etc. Disassembly refers to the operation of disassembling equipment, components or systems into individual parts in a certain order and method for inspection, repair, replacement or upgrade, such as disassembling electrical connectors, disassembling bolts, disassembling spring rings, etc. Insurance refers to the operation of preventing circuit or equipment damage due to overload, short circuit and other abnormal conditions, such as fuse insurance, plug insurance, open longitudinal insurance, etc. Welding refers to the method of melting and connecting two or more metal parts together by heating, such as terminal welding construction, soldering, etc. Clamping refers to the method of connecting two or more parts together by clamping or clamping, which is usually used in occasions that require quick connection or disassembly, such as T-head clamping tool clamping, short handle clamping tool clamping, etc. Insulation stripping refers to removing the insulation layer of wires or cables for connection, welding or other maintenance operations. Sealing refers to using sealing materials or seals to close the joint surface of equipment, components or systems to prevent leakage of liquids, gases or solid particles, such as injection sealing, hole and groove sealing, etc. Transportation refers to the process of moving equipment, components or objects from one place to another. During the repair process, transportation may involve transporting damaged equipment to the repair site or transporting repaired equipment back to the use location.

[0104] Based on the above analysis, eight cases are selected from the eight categories of repair process: installing bolts, disassembling spring rings, plug insurance, soldering, short handle clamping tool clamping, insulation layer stripping, injection sealing and transporting objects. The specific repair process is shown in Table 5.

[0105] Table 5: Typical repair process and cases

[0106]

[0107] The above eight typical repair processes are modeled using the SysML stereotype established as described above, as shown in Figures 6(1)-(8). Figure 6(1) is installing bolts, Figure 6(2) is disassembling spring rings, Figure 6(3) is plug insurance, Figure 6(4) is soldering, Figure 6(5) is short handle clamping tool clamping, Figure 6(6) is insulation layer stripping, Figure 6(7) is injection sealing, and Figure 6(8) is transporting objects.

[0108] Specifically, the repair process modeling based on SysML stereotype and activity diagram:

[0109] Based on the modeling form of typical maintenance process, the complete maintenance process is modeled, and the maintenance process model of the installation of the case body is constructed by using eight types of object structures of maintenance process, maintenance step, maintenance object, maintenance equipment, maintenance tool, maintenance personnel, maintenance resource and maintenance philosophy, and six types of relationship structures of execution, need, obey, contain, act on and guarantee, as shown in Figure 7

[0110] In one embodiment, the evaluation and output module uses the ontology reasoning of the Protégé maintenance process instance to verify according to the established maintenance process model, including:

[0111] The rule establishment unit establishes the Protégé maintenance process ontology reasoning rule;

[0112] The evaluation unit verifies the established maintenance process model based on the reasoning rule;

[0113] The output unit outputs the reasoning verification result.

[0114] Specifically, the Protégé maintenance process ontology reasoning rule is used:

[0115] In Protégé, the SWRL (Semantic Web Rule Language) of ontology reasoning is an OWL (Web Ontology Language) based rule language, which allows users to express rules in an intuitive way to enhance the expressiveness and reasoning ability of ontology. Based on this, a set of reasoning rules are formulated for the maintenance process ontology to verify whether the logical relationship of the established maintenance process instance model is reasonable. The reasoning rule is mainly the reasoning rule based on semantic relationship.

[0116] In the maintenance process ontology, many instances have semantic relationships in structure and behavior, and the following axioms are considered: maintenance step A obeys maintenance philosophy C, and maintenance step A is part of maintenance process B. In this axiom, there are two explicit semantic associations:

[0117] (1) AbrideBy (?maintenance step A,?maintenance philosophy C): maintenance step A obeys maintenance philosophy C.

[0118] (2) IsPartOf (?maintenance step A,?maintenance process B): maintenance step A is part of maintenance process B.

[0119] In addition, there is an implicit relationship behind the two explicit relationships: ​

[0120] (3) AbrideBy(?maintenance process B,?maintenance philosophy C): Maintenance process B complies with maintenance philosophy C.

[0121] Based on this implementation, we can reason about the explicit and implicit relationships of many newly added instances in the maintenance process ontology. We developed six types of reasoning: tool requirement reasoning, maintenance equipment requirement reasoning, maintenance criterion transfer reasoning, maintenance work step transfer reasoning, maintenance resource transfer reasoning, and maintenance personnel reasoning. We then compared the reasoning results with the modeling results to determine the rationality of the modeling. Table 6 shows the reasoning rules for the maintenance process ontology using Protégé.

[0122] Table 6 Maintenance process ontology reasoning rules

[0123]

[0124] Specifically, the ontology reasoning of the maintenance process instance is verified:

[0125] Based on the inference rules in Table 6, Figure 8 The established maintenance process model is used for reasoning verification. For example, the maintenance tools required for the bearing seat heating maintenance step can be inferred based on the maintenance tools of the same type of maintenance steps. The type of bearing seat heating belongs to the heating type maintenance process, such as Figure 7 As shown, in Protégé, it can be deduced that the maintenance tool for bearing seat heating is the oil heating box, which is ​ The established maintenance process model is consistent.

[0126] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0127] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A maintenance process modeling system based on ontology and metamodel, characterized by: include: Ontology construction module: construct application ontology oriented to maintenance process; Metamodel construction module: constructs maintenance process metamodel based on SysML stereotypes according to the application ontology; Maintenance process building module: Based on the meta-model, the maintenance process model of the application instance is established using SysML; Evaluation and output module: Based on the application ontology, Protégé is used to perform ontology reasoning of the maintenance process instance, verify the rationality of the maintenance process model, and output the results.

2. A maintenance process modeling system based on ontology and metamodel according to claim 1, characterized in that: The ontology building module includes: Analysis and expression model construction unit, establish the maintenance process knowledge concept analysis and expression model; The element extraction unit analyzes the maintenance knowledge elements of the maintenance process through the maintenance process knowledge concept analysis expression model; Ontology construction unit, which constructs application ontology oriented to maintenance process based on maintenance knowledge elements of maintenance process; The visualization display unit visualizes the constructed application ontology.

3. A maintenance process modeling system based on ontology and metamodel according to claim 2, characterized in that: The meta-model building module includes: Element relationship analysis unit, which analyzes the relationship between maintenance knowledge elements in the maintenance process and builds a systematic maintenance framework; The meta-model construction unit uses SysML stereotypes to formally model the maintenance knowledge elements of the maintenance process and the relationships between the maintenance knowledge elements of the maintenance process.

4. A maintenance process modeling system based on ontology and metamodel according to claim 2, characterized in that: The maintenance process building blocks include: a classification and modeling unit, which classifies the maintenance process classification and models the classified maintenance process based on the meta-model; Complete modeling unit, models the complete repair process.

5. The maintenance process modeling system based on ontology and metamodel according to claim 1, characterized in that: The evaluation and output module includes: Rule building unit, which builds the reasoning rules of Protégé's maintenance process ontology; An evaluation unit, which performs reasoning verification on the established maintenance process model based on the inference rules; Output unit, outputs the reasoning verification results.

6. A maintenance process modeling system based on ontology and metamodel according to claim 5, characterized in that: The rule establishment unit establishes the maintenance process ontology reasoning rules of Protégé, including: Tool requirement reasoning rules, maintenance equipment requirement reasoning rules, maintenance criteria transfer reasoning rules, maintenance work step transfer reasoning rules, maintenance resource transfer reasoning rules and maintenance personnel reasoning rules.

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