BIM information digitization processing method and system based on ifc-grid standard

Abstract

The application relates to a BIM information digital processing method and system based on an IFC-GRID standard, and the method comprises the following steps: obtaining BIM data stored in an IFC standard to be processed; converting geometric model data in the BIM data into a form of boundary representation entities, swept entities, constructed entities and surface models for shape expression; converting display data in the BIM data into colored display and material map display; and extending and customizing attribute data in the BIM data, including object extension and object attribute extension, wherein the object extension is described by using an IFC standard language, and the object attribute extension describes entity characteristics by defining new attribute sets and attribute types. Compared with the prior art, the application improves the data conversion efficiency of the IFC-GRID standard, and the function is stable and reliable, which is beneficial to constructing an IFC-based unified data expression mode IFC-GRID standard.

Description

Technical Field

[0001] The present invention relates to the technical field of BIM data processing, and in particular to a BIM information digital processing method and system based on the IFC-GRID standard. Background Art

[0002] At present, the digitalization of power grid infrastructure projects mainly revolves around BIM (Building Information Modeling) technology and related technologies, and mainly conducts visualization and decision analysis research in engineering design, construction, management, etc. BIM technology has gradually become a common digital technology in the field of power grid engineering.

[0003] However, because BIM technology was primarily developed for the construction engineering sector, its native technology for the digitization of power grid engineering is virtually nonexistent. The localization of key BIM technologies for power grid engineering presents numerous challenges. Without unified data exchange standards, it is impossible to expand BIM models and corresponding model data encoding within the electrical engineering field. Professional BIM software for power grid engineering is urgently needed, and the localization of BIM technology needs to be promoted. In existing research, to adapt the IFC standard to areas not covered by official standards, such as railway transportation and bridge components, researchers often study the expression system and operating mechanism of the IFC standard and expand the corresponding IFC standard entities based on application requirements to perform IFC expression.

[0004] In the application process of BIM technology, data interaction of power grid projects is inevitable. In view of the lack of interaction standards, it is necessary to conduct research on relevant international standards, expand the IFC standard common entities in the field of power grid projects, and form the IFC-GRID standard based on power grid projects to provide a data base for BIM-based digital power design, thereby developing domestically produced key BIM technologies for power grid projects and forming a domestically produced digital design system. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a BIM information digital processing method and system based on the IFC-GRID standard, improve the data conversion efficiency of the IFC-GRID standard, and have stable and reliable functions.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for digitally processing BIM information based on the IFC-GRID standard, wherein the IFC-GRID standard is based on the IFC standard to extend the data structure and link types with external classification systems, the method comprising the following steps:

[0008] Obtain BIM data stored in IFC standards to be processed;

[0009] The geometric model data in the BIM data is converted into shape expression in the form of boundary representation entities, swept entities, constructed entities and surface models. The boundary representation entity uses boundary surface constraints to represent three-dimensional objects; the swept entity uses implicit modeling methods to stretch and rotate two-dimensional sections to create three-dimensional entities; the constructed entity represents three-dimensional objects by performing Boolean operations on objects or primitives;

[0010] Converting the display data in the BIM data into shaded display and material mapping display, wherein the shaded display conversion process is to convert the color component data in the display data into normalized floating point numbers; the material mapping display conversion process is to convert the display data into storage in the form of image links, binary streams or pixels;

[0011] The attribute data in the BIM data is expanded and customized, including object extension and object attribute extension. The object extension is re-described using the IFC standard language, and the object attribute extension describes the entity characteristics by defining new attribute sets and attribute types.

[0012] Furthermore, during the geometric model data conversion process, the BIM data is also classified to distinguish whether it is a conventional model or a complex model. If it is a conventional model, the geometric model is described using boundary representation entities and swept entities; if it is a complex model, it is described using a surface model.

[0013] Furthermore, during the shading display process, the material with the texture is displayed using the material base color as the unified rendering color of the model surface.

[0014] Furthermore, the image link in the conversion process of the material map display is a local path or a network path; the binary stream is stored in a hexadecimal text format; and the pixel format stores the color value of each pixel in a text format.

[0015] Furthermore, the display data conversion process also includes expressing the internal structure in a dotted line style through a line blanking algorithm.

[0016] Furthermore, the attribute data extension customization process specifically describes the extension category and customized entity Schema information in Express mode. When the export action is executed, the IFC extension objects and attributes of the power grid engineering category are obtained by performing IFC-GRID standard parsing.

[0017] Furthermore, the object property extension extracts and converts the properties of the object, and converts the properties in the internal data structure into IFC property sets and property types.

[0018] Furthermore, the attributes in the internal data structure include material, cost and performance parameters.

[0019] Furthermore, the conversion of the attributes includes unit conversion.

[0020] Furthermore, the method further includes: determining whether the volume of the model file obtained after BIM data processing is greater than a preset volume threshold; if so, performing multiplexing and compression processing on the geometric model data and attribute data.

[0021] The present invention also provides a BIM information digital processing system based on the IFC-GRID standard, comprising a memory and a processor, wherein the memory stores a computer program, and the processor calls the computer program to execute the steps of the above-mentioned method.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) In order to implement the setting of IFC-GRID standard, the present invention provides a conversion and analysis solution for IFC-GRID standard data. Through the geometric capability, display capability, and component data encapsulation capability, it can match the geometric information, attribute information, style information, relationship information and other contents in the BIM model with the mapping rules set by the IFC-GRID standard, thereby improving the data conversion efficiency of the IFC-GRID standard and making the function stable and reliable.

[0024] (2) The present invention integrates the IFC-GRID standard into basic applications and design applications, reducing the designer's secondary information matching of the model. Through customized applications, the design model that meets the delivery standards is efficiently produced. The data conversion of the IFC-GRID standard model results is realized through the mapping rules provided by the IFC Schema file. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a flow chart of a method for digital processing of BIM information based on the IFC-GRID standard provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment provides a BIM information digital processing method based on the IFC-GRID standard. The IFC-GRID standard is based on the IFC standard to expand the data structure and connect with the types in the external classification system. The method includes the following steps:

[0031] S1: Obtain BIM data to be processed that is stored in the IFC standard;

[0032] S2: Convert the geometric model data in the BIM data into shape expressions in the form of boundary representation entities, swept entities, constructed entities, and surface models. Boundary representation entities use boundary surface constraints to represent three-dimensional objects; swept entities use implicit modeling methods to stretch and rotate two-dimensional sections to create three-dimensional entities; constructed entities represent three-dimensional objects by performing Boolean operations on objects or primitives;

[0033] S3: Convert the display data in the BIM data into shaded display and material mapping display. The conversion process of shaded display is to convert the color component data in the display data into normalized floating-point numbers; the conversion process of material mapping display is to convert the display data into storage in the form of image links, binary streams or pixels;

[0034] S4: Expand and customize the attribute data in BIM data, including object extension and object attribute extension. Object extension is re-described using the IFC standard language, and object attribute extension describes entity characteristics by defining new attribute sets and attribute types.

[0035] The following is a detailed description:

[0036] 1. BIM standards define the role and status of each standard in data sharing and integration for general engineering projects. For example, IFC serves as the data foundation for BIM full-lifecycle management, IDM is a compilation manual for converting abstract information required by various disciplines into the BIM standard data language, and MVD is a sub-model generated by different disciplines for specific applications such as structural calculation, construction simulation, and cost estimation. To ensure that the geometric accuracy and information depth of power grid engineering information models delivered by engineering design participants throughout the substation lifecycle are scientifically sound, meet actual project requirements, and conform to international information standards for open sharing, the proposed domestic BIM technical standard system for power grid engineering projects consists of four components: data format standards, data exchange standards, model classification and encoding standards, and data delivery standards. These four standards extend the IFC, MVD, IFD, and IDM standards within the international information standard system to form the standardized data support for the IFC-GRID (GIM Grid Information Model), providing a foundation for the extraction of professional knowledge and project data mining in power grid engineering projects.

[0037] (1) IFC standard

[0038] IFC (Industry Foundation Classes) is the core data standard for BIM (ISO10303-21). It is a universal BIM data organization framework that aims to become a link for information sharing and transmission between different fields of large-scale projects such as civil engineering and electrical engineering, especially between different application software. Most current BIM software supports the reading and transcription of IFC data files. The IFC standard itself is an object-oriented modeling standard, an extension of EXPRESS in the application of civil engineering information technology. It contains a large number of definitions of product entities, process entities, geometric resources, role resources, etc. related to civil engineering, electrical engineering, etc.

[0039] The IFC standard is an object-oriented information model data standard developed using the EXPRESS description language. It comprises four conceptual layers: domain layer, interaction layer, core layer, and resource layer. To reduce unnecessary development complexity, a gravity-based reference model is used, allowing concepts in higher layers to reference concepts in lower layers, but not vice versa. This ensures the stability of the overall information resource and enhances the scalability of the data standard. Each layer contains different data types and entity definitions, which serve as the basic elements of the model description.

[0040] The latest version of the IFC standard is IFC4.3. Starting with the major update from IFC2x3 to IFC4, buildingSMART, the official IFC organization, has gradually shifted its focus from buildings to the full lifecycle management of urban assets. This has gradually incorporated various urban infrastructure areas, such as railways, bridges, ports, and roads, as well as shared concepts and geometric representations for urban infrastructure projects. This paves the way for potential expansion of other infrastructure projects, providing a favorable foundation for the expansion of power grid projects. Starting with IFC4, the IFC standard has gradually expanded its description of urban infrastructure to include infrastructure projects in areas such as railways, roads, ports, and waterways. It not only refines the specialized product and product type structures for these infrastructure areas, but also incorporates spatial structure decomposition definitions and geometric representations of complex entities within these disciplines. Therefore, guided by the experience of previous IFC standard iterations, this project will develop an extension of the IFC standard to the power grid engineering field, namely the IFC-GRID standard, to meet the information needs of power grid engineering projects requiring compatibility, openness, high-precision modeling, and standardization.

[0041] (2)MVD standard

[0042] MVD (Model View Definition) is the exchange specification for BIM data, and is generally regarded as a subset of data exchange for specific purposes between different disciplines under the overall IFC framework. The complete IFC framework (IFC schema) is often too bloated for a specific engineering application scenario. In the more widely used version, IFC2x3_TC1 contains 653 entities, while the latest IFC4x3_RC4 has been expanded to 876 entities, and as time goes by, the IFC standard will include more entity information. Therefore, in the actual data exchange application of different professional software in the project, not all entities are often transmitted. Instead, the original model is divided into multiple MVDs for shared transmission according to the needs of different disciplines, which can effectively improve the efficiency of information sharing.

[0043] Under the guidance of IDM, MVD determines the model subset containing the information required for each stage of the IFC model data process, which is used for model transfer between software. The complete IDM standard consists of five main parts: process map, exchange requirements, functional components, business rules, and verification tests. The core is the process map and exchange requirements. For specified work requirements, the process map defines the participating roles and information exchange nodes. The exchange requirements explain the specific information exchange details of the process map, enabling information exchange between BIM users and providing detailed text descriptions. Functional components are the information units of IDM data, and a single exchange requirement is composed of several functional components. Business rules provide multiple constraints for a specific process. Verification tests verify that each exchange requirement is accurate and met.

[0044] The development of MVD for power grid projects can follow the following process: List-up stage, PM (Process Map) stage, ER (Exchange Requirement) stage, MVD stage, and SI (Software Implementation) stage.

[0045] The final development output of the power grid project information model view definition should include three parts: 1) An overall description of the power grid project information model view (MVD). To enable the power grid project information model to be applied to relevant scenarios and form a corresponding model, it is necessary to accurately define the data format for power grid project information exchange based on IFC-GRID. This project proposes to use IFC-GRID binding as a description. By drawing a diagram composed of various IFC-GRID concepts, the various information required for power grid project information exchange, such as components and attributes, is fully expressed. 2) An MVD-IFC-GRID binding diagram (diagram). Draw an MVD-IFC-GRID binding diagram (diagram) to describe the diagrams of the power grid project information model entities. Each variable concept in the diagram corresponds to a corresponding IFC-GRID entity object. The hierarchical structure is also combined to clarify the relationships between the concepts. 3) An MVD-IFC-GRID binding document description. A corresponding description document is developed for each concept in the power grid project MVD, and the attribute values ​​of each entity in the description document are declared using symbolic descriptions.

[0046] (3) IFD standard

[0047] The IFD standard, standing for International Framework for Dictionaries, aims to define a scientific approach to summarizing, defining, identifying, and organizing engineering concepts. The IFD standard requires attributes or characteristics of information content, distinguishing and categorizing information according to specific principles and methods, and establishing a classification system or order of arrangement. The existing IFD standard encodes existing entity categories in IFC, but lacks encoding for the various components and equipment types involved in power grid projects, necessitating appropriate expansion.

[0048] Based on the actual situation and design practices of power grid projects and the "Power Grid Project Digital Delivery Standard", IFD coding information is added to the power grid project BIM model based on the following principles:

[0049] First, the naming of projects, systems, and BIM components should comply with certain naming principles. All names must consist of uppercase letters and numbers. The project system code is composed of three English letters, and the category keyword of the equipment is also composed of three English letters. The equipment type or attribute, as the specific type of the main equipment, can be composed of letters and Arabic numerals. Professional keywords can be split into multiple fields based on the characteristics of different professions, separated by "". In principle, the same name is used for equipment of the same model and specification. If there are differences in the appearance of the model due to different installation methods or layout adjustments, "_A (uppercase English serial number)" will be added to the name.

[0050] Secondly, based on the hierarchical principle, power grid projects can be categorized by project type into substation projects, overhead line projects, and cable line projects. Each project type can be systematically divided into four tiers based on their specific disciplines: Level I, Level II, Level III, and Level IV. Level I systems directly correspond to the project type. The specific system division principle is shown in the figure. Coding is performed according to the system concepts involved in the four tiers of system division. Taking "primary equipment" as an example, the Level I system "substation project" is coded as "TSE," the Level II system "electrical engineering" is coded as "EEG," the Level III system "primary electrical equipment" is coded as "PEL," and the Level IV system "primary equipment" is coded as "PEE." The IFD code for "primary equipment" is "TSE_EEG_PEL_PEE."

[0051] Third, BIM components and equipment are the foundational elements of projects and systems. Level V systems categorize equipment and materials, while Level VI systems assign categories based on equipment attributes or characteristics. For example, for a main transformer belonging to the "primary equipment" system, the category keyword is "transformer," coded as "MTF," and the equipment type is "main transformer," coded as "MT." Therefore, the IFD code for the main transformer is "TSE_EEG_PEL_PEE_MTF_MT."

[0052] This project implements the classification and coding of power grid engineering data by sorting out the classification and grading requirements of concepts in power grid engineering and coding them according to specific naming rules.

[0053] (4) IDM Standard

[0054] An Information Delivery Manual (IDM) is a method for defining and documenting practical application objectives and corresponding data requirements. It can be used to detail the information and data required by specific roles across different domains throughout the lifecycle, breaking down relatively abstract industry requirements into a human-readable information requirements network. The IDM defines the process relationships and model information requirements for each phase of a specific business. A complete IDM standard consists of five main components: process maps, exchange requirements, functional components, business rules, and verification tests. The core components are process maps and exchange requirements. For specific work requirements, process maps define the participating roles and information exchange nodes. Exchange requirements describe the specific information exchange details within the process map, enabling information exchange between BIM users and providing detailed textual descriptions. Functional components are the units of IDM data information, and each exchange requirement is composed of several functional components. Business rules provide multiple constraints for a specific process. Verification tests verify that each exchange requirement is accurate and met.

[0055] 2. IFC-GRID Standard Principles

[0056] IFC-GRID standard research should follow the following basic principles:

[0057] (1) The standard architecture should be consistent with the overall infrastructure architecture.

[0058] (2) The standards should cover all professional fields related to power grid engineering, including primary and secondary electrical systems, intelligent auxiliary control, cables and accessories, building structures, HVAC, water supply and drainage, fire protection, ground wires, insulator hardware, foundations, towers, pipes, cable trenches, power tunnels, work wells, etc. in substation engineering.

[0059] (3) The standard should cover the entire life cycle of power grid project design, construction, operation and maintenance.

[0060] (4) The standard is aligned with international information standards, compatible with the industry-recognized IFC standard, and incorporates the implementation characteristics of domestic power grid engineering projects.

[0061] (5) Try to use the existing data structure of the IFC standard to minimize the number of extended information models, reduce development costs, and improve reusability.

[0062] Building IFC extensions requires structural decomposition of power grid projects. This decomposition primarily targets specific local models, reflecting the project's organizational framework and model management capabilities within these local models. Generally speaking, a project can be decomposed into a spatial structure and a functional structure. The spatial structure expresses the spatial organization of the project and is typically decomposed based on spatial proximity. A project's spatial structure can be divided into multiple hierarchies, and a hierarchical spatial structure model can be established through one-to-many aggregation relationships. The functional structure represents a collection of elements distributed within the same project that share common functions and purposes. It is often used to analyze and decompose project functions. It lacks geometric or topological combinations, and no specific object has a specific positional relationship within the functional structure. A component is an instantiation of a type object, describing the components of entities generated during project activities. It possesses geometric and attribute information. Components can be logically contained within a spatial or functional structure. Type objects contain shared geometric and attribute information for objects of the same type.

[0063] Building IFC extensions requires functional decomposition of power grid projects. This decomposition breaks down power grid projects into distinct subprojects, facilitating simultaneous multi-threaded research. Given the specialized nature of power grid projects, they can be categorized by project type into substation projects, overhead line projects, and cable line projects. Each project type is further divided into systems based on the power grid project's information structure, from large to small. These systems can be categorized into Level I (grid level), Level II (project level), Level III (professional level), Level IV (system level), Level V (equipment and material level), and Level VI (attribute level, which encompasses infinitely expandable attributes and features).

[0064] Building on the existing IFC 4.3 standard and the decomposition of power grid projects, 4IFC-GRID further defines the entities, attributes, and relationships that need to be implemented across the six conceptual layers of IFC. For example, at the domain layer, it adds substation engineering, overhead line engineering, and cable line engineering domain modules; at the shared layer, it adds a cable and accessories shared module; and at the core and resource layers, it adds corresponding product extensions and geometry, material, and metric resources based on actual needs.

[0065] Finally, the above concepts are expanded to be compiled and formed into a structured, machine-readable standard definition form using the EXPRESS description language.

[0066] In order to form a standard IFC-GRID model, this embodiment adopts the form of directly extending IFC data entities (adding entities, types, etc.) to expand the equipment in the power grid engineering field.

[0067] 3. Digital processing of BIM information based on IFC-GRID standard

[0068] The digital processing of BIM information based on the IFC-GRID standard requires parsing and integrating IFC general standard component geometry, display data, attribute data, and relationship data. Furthermore, IFC-GRID standard extensions are added to this data, ultimately enabling the exchange and parsing of standard data within the domestic BIM foundation enabling platform for power grid projects based on the IFC-GRID standard. In the specific technical implementation, by deeply analyzing the basic syntax of the IFC EXPRESS language and the schema entity information descriptions in the IFC-GRID standard, extended categories and customized entity information related to power grid projects are integrated. During conversion or parsing, IFC extended entities for power grid projects are obtained from the Exp file content. During conversion, the geometry, display, and attribute data are specifically processed and transferred to the IFC-GRID standard model using Grep whenever possible. During parsing, data loss between the IFC-GRID standard and the design model is minimized. By creating corresponding instances, assembling geometry and attribute information, and combining them with display data, the design model content is precisely expressed in the model space.

[0069] 3.1. Geometric Data Adaptability Processing

[0070] In the general IFC standard, various types of geometric model data can be stored. Among them, Curve2D, GeometricSet, and GeometricCurveSet are used to describe models composed of basic elements such as points, lines, and surfaces; SurfaceModel is used to describe surface models; and SolidModel is used to describe solid models. It can be further divided into various types such as SweptSolid, Brep, CSG, Clipping, and AdvancedSweptSolid.

[0071] For 3D solid models, the most basic and commonly used shape representation methods are: boundary representation solid (Brep), swept solid (SweptSolid), and constructed solid (CSG). Brep uses boundary surface constraints to represent a 3D object and is often used to represent complex entities. Swept solids use implicit modeling to create a 3D solid by applying operations such as stretching and rotating a 2D cross-section. CSG, on the other hand, uses basic objects or primitives (spheres, cylinders, cones) and the results of a series of Boolean operations (difference, union, and intersection) to represent a 3D object. However, CSG relies on predefined objects and primitives and can create relatively complex objects. In power grid engineering models, after studying the geometric modeling characteristics of power grid engineering models, equipment, and facilities, the boundary representation solid (Brep) and swept solid (SweptSolid) methods are used for common model descriptions, while the surface model method is used for complex models. Ultimately, this provides a means for expressing and exchanging the geometric data of the entire power grid engineering model.

[0072] To meet the requirements of IFC-GRID standard implementation, geometric representations must be not only internally parsed but also externally exported. The purpose of parsing is to reconstruct IFC objects within the platform, while the purpose of conversion is to deliver the digital model of the power grid project to downstream disciplines or processes in the IFC-GRID standard format, ensuring accurate and consistent model data.

[0073] 3.2. Geometric Data Adaptability Processing

[0074] In the general IFC standard, display data includes geometry-based shading styles and object-based material styles. During the data conversion and parsing process, these display data need to be reorganized and associated with geometric entities to ensure their correct representation and parsing in IFC-GRID. The domestic BIM basic enabling platform for power grid engineering provides an interface to convert the general IFC standard IfcProductRepresentation into a set of Geometry objects within the platform, and includes its style data. There are two ways to express the style data IfcStyleItem. One is to associate IfcMaterialDefinitionRepresentation, and then set the style association through IfcMaterial and IfcProduct; the other is to directly associate the model's geometric data with IfcGeometryRepresentationItem.

[0075] The display modes supported in IFC-GRID are divided into shaded display and material mapping display. Shaded display is relatively simple to handle. You only need to note that the color component data recorded in the IFC-GRID standard file are all normalized floating-point numbers. In this mode, materials with maps can also be displayed using the material base color as the unified rendering color of the model surface. The material mapping display mode is relatively complex and is divided into three storage methods: image link, binary stream, and pixel. Image links can be local paths or network paths. Binary streams are stored as text represented in hexadecimal. Similarly, the IFC standard does not specify a compression method, which takes up a lot of space. The pixel method directly stores the color value of each pixel in text format, which takes up the most space. However, existing platforms that support general IFC file parsing and preview have little support for image links. The domestic BIM foundation enabling platform for power grid projects needs to consider aspects such as loading performance and display optimization. Therefore, support for image link storage methods has been provided to enable greater flexibility in IFC-GRID display data design.

[0076] Due to the complexity of power grid engineering components, the ability to display the internal structure of components is required in many scenarios. For the underlying 3D graphics engine, the line hidden line algorithm is usually provided for use when 3D models are used for 2D drawing. Customized dashed line styles can be used to express the internal structure.

[0077] Based on the overall performance perspective of the domestic BIM basic enabling platform for power grid projects based on IFC-GRID data support, the principle of geometric sharing needs to be applied. Therefore, when the platform parses the geometry, it returns the corresponding data when encountering a reference, including the transformation matrix, the referenced Entity Id, etc. When customizing business functions, this information can be updated to create a mapping from Entity Id to referenced Element Id, and then create a reference node to enable geometric sharing and display merging of components based on the same Entity Id, thereby improving the display performance of the enabling platform.

[0078] 3.3. Attribute data adaptability processing

[0079] In the general IFC standard, the extended customization of object property data is generally achieved by defining new property sets (IfcPropertySet) and property types (such as IfcPropertySingleValue and IfcPropertyEnumeratedValue). The specific steps include creating new property sets to contain properties for specific requirements, defining new property types to adapt to project needs, and then associating these property sets with IFC objects and ensuring their correct representation and parsing in IFC files. These are also reflected in the IFC-GRID standard. Therefore, this route must also be followed in the conversion and parsing of IFC-GRID standard models to ensure data integrity and interoperability.

[0080] During the IFC-GRID extended object conversion process, the geometry does not change the modeling method of existing components in the enabling platform. The original modeling method is re-described using the standard language of IFC. The object properties also use attribute sets and attribute extensions to describe entity characteristics. The internal attributes in the design model need to be mapped to the IFC standard attribute set or the non-standard attribute set defined in IFC-GRID. This includes extracting and converting the attributes of each object, converting them into corresponding attribute sets and attribute types, and converting the attributes in the internal data structure (such as material, cost, performance parameters, etc.) into IFC attribute sets (such as IfcPropertySet) and specific attribute types (such as IfcPropertySingleValue). In this process, it is necessary to ensure the correctness and consistency of attribute values ​​and handle possible unit conversions (such as length units, area units, etc.). The categories defined by the IFC-GRID standard extension should be converted according to the attribute sets designed in the Schema to obtain accurate and unified digital model data.

[0081] Due to the need for compatibility with the extended IFC-GRID standard, the domestic BIM foundation enabling platform for power grid projects must be able to write non-IFC standard attributes. This allows the IFC-GRID standard model file to be used during the parsing process. When creating components, non-standard IFC property sets can be imported. The IfcPropertySet attribute can be set to each IFC node, and the content of the IfcPropertySingleValue can be presented using a single attribute and attribute value. Considering the file size of the IFC-GRID model and the data conversion performance, the geometry and attribute information of components referenced by geometric references are also reused and compressed during data conversion.

[0082] In the specific technical implementation, we gain a deep understanding of the basic syntax of the IFC Express language and access the extended categories and custom entity schema information described in Express. During export, we parse the IFC-GRID standard in the Express standard file to obtain the IFC extended entities for the power grid engineering category. During export, we create the corresponding instances and attributes to achieve the extension purpose. The main steps are as follows:

[0083] (1) Understand the basic syntax of the EXPRESS language and be familiar with its basic syntax and rules, including data types, keywords, and entity definitions. The IFC Schema file primarily describes model information through entities defined in the EXPRESS language. The EXPRESS information modeling language is the foundation and core of the Standards for the Exchange of Product Model Data (STEP) and is primarily used for object-oriented information description. Unlike other object-oriented programming languages, the EXPRESS language sacrifices the executable nature of some code while significantly improving computer readability of the described information.

[0084] (2) Read and parse the EXPRESS file definition generated by the IFC-GRID standard: Use an appropriate programming language (such as Python, C++, etc.) to read the EXPRESS file definition and use the corresponding parser to parse it into operable code. The IFC Schema uses the EXPRESS language to aggregate the abstract entities formed by various things in the engineering project and specifies the mapping rules between various entities and the BIM model. This stage is to explain these mapping rules.

[0085] (3) Extracting entity information: Once the EXPRESS file is successfully parsed, the entity information defined therein can be extracted, including mapping rules for entity type, geometry, style, attributes, relationships, etc. This information will be used to create enabling platform model entities or build IFC-GRID instance objects based on model entities. When the program is parsed, this rule will be called to complete the mapping between the design model information and the IFC-GRID standard to achieve data conversion.

[0086] (4) Implementation of IFC-GRID standard model data exchange: Based on the extracted entity information, the mapping rules specified in the Schema file are applied to create actual IFC entity instances. This usually involves assigning unique identifiers to the entities, setting entity attributes, and establishing relationships with other entities. The power grid engineering model object instances will reflect clear geometric shapes and specific spatial relationships. The expression of 3D model geometry-related information is fully understood. This information is accurately and efficiently extracted from the model file and converted into the desired expression in the IFC-GRID standard. Alternatively, the geometric shapes and spatial relationships implemented in the IFC-GRID standard description are restored to instance objects in the 3D model.

[0087] Example 2

[0088] This actual example provides a BIM information digital processing system based on the IFC-GRID standard, including a memory and a processor, wherein the memory stores a computer program, and the processor calls the computer program to execute the steps of the BIM information digital processing method based on the IFC-GRID standard as described above.

[0089] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A BIM information digital processing method based on the IFC-GRID standard, characterized in that: The IFC-GRID standard is based on the IFC standard to expand the data structure and connect with the types in the external classification system. The method includes the following steps: Obtain BIM data stored in IFC standards to be processed; The geometric model data in the BIM data is converted into shape expression in the form of boundary representation entities, swept entities, constructed entities and surface models. The boundary representation entity uses boundary surface constraints to represent three-dimensional objects; the swept entity uses implicit modeling methods to stretch and rotate two-dimensional sections to create three-dimensional entities; the constructed entity represents three-dimensional objects by performing Boolean operations on objects or primitives; Converting the display data in the BIM data into shaded display and material mapping display, wherein the shaded display conversion process is to convert the color component data in the display data into normalized floating point numbers; the material mapping display conversion process is to convert the display data into storage in the form of image links, binary streams or pixels; The attribute data in the BIM data is expanded and customized, including object extension and object attribute extension. The object extension is re-described using the IFC standard language, and the object attribute extension describes the entity characteristics by defining new attribute sets and attribute types.

2. The BIM information digital processing method based on the IFC-GRID standard according to claim 1 is characterized in that: During the geometric model data conversion process, the BIM data is also classified to distinguish whether it is a conventional model or a complex model. If it is a conventional model, the geometric model is described using boundary representation entities and swept entities; if it is a complex model, it is described using a surface model.

3. The BIM information digital processing method based on the IFC-GRID standard according to claim 1 is characterized in that: During the shading display process, the material with the map is also displayed using the material base color as the unified rendering color of the model surface.

4. The BIM information digital processing method based on the IFC-GRID standard according to claim 1 is characterized in that: The image link in the conversion process of the material map display is a local path or a network path; the binary stream is stored in text represented by hexadecimal; the pixel method stores the color value of each pixel in text form.

5. The BIM information digital processing method based on the IFC-GRID standard according to claim 1 is characterized in that: The display data conversion process further includes expressing the internal structure in a dotted line style through a line blanking algorithm.

6. The BIM information digital processing method based on the IFC-GRID standard according to claim 1 is characterized in that: The attribute data extension customization process specifically describes the extension category and customized entity Schema information in Express mode. When the export action is executed, the IFC extension objects and attributes of the power grid engineering category are obtained by performing IFC-GRID standard parsing.

7. The BIM information digital processing method based on the IFC-GRID standard according to claim 1 is characterized in that: The object property extension extracts and converts the properties of the object, and converts the properties in the internal data structure into IFC property sets and property types.

8. The BIM information digital processing method based on the IFC-GRID standard according to claim 7 is characterized in that: The attributes in the internal data structure include material, cost and performance parameters.

9. The BIM information digital processing method based on the IFC-GRID standard according to claim 7 is characterized in that: The method further includes: determining whether the volume of the model file obtained after BIM data processing is greater than a preset volume threshold; if so, performing multiplexing and compression processing on the geometric model data and attribute data.

10. A BIM information digital processing device based on the IFC-GRID standard, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor calls the computer program to execute the steps of any one of the methods according to claims 1 to 9.

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