IFC sub-model extraction method

Abstract

The invention relates to an IFC sub-model extraction method, which comprises the following steps of: 1, reading a filtering condition t, and extracting a core entity E1 from an IFC complete model Lc according to the t; 2, analyzing the core entity E1, and if the core entity E1 is empty, ending extraction; if te is a product entity, directly entering the step 3; if te is a process entity, extracting an IFC instance set of the process entity; if te is organization, control, production materials and grouping entities, IFC instance sets of the organization, control, extracting production materials and grouping entities; if te is a type entity, extracting an IFC instance set of the type entity; if te is a project entity, extracting an entity-level sub-model from the IFC complete model Lc according to MVD, wherein MVD = {cj}; if te is an attribute entity, extracting an IFC instance set of the attribute entity; and 3, calculating and extracting related IFC instances of the core entity E1. According to the extraction method, unnecessary instances are filtered out, strong correlation instances are extracted, and it is guaranteed that the extracted IFC sub-model is combined with the minimum IFC instances meeting the use requirement.

Description

technical field [0001] The invention relates to the field of building informationization, in particular to an IFC sub-model extraction method. Background technique [0002] The IFC (Industry foundation Classes) standard is an open and standardized data storage format for Building Information Modeling (BIM). Models created by BIM modeling software can be exported as IFC format files for storage. The IFC standard covers various types of IFC entities c i , the IFC standard stores individual building components and their relationships as instances of various types of IFC entities. Each IFC entity has many attributes for storing building information. A complete model of IFC can be represented by a list of instances of IFC entities Lc={c i ,{e ij}},e ij is entity c i instance of . [0003] Such as figure 1 As shown, IFC entities can be divided into independent exchange entities and non-independent exchange entities (also called resource entities). Independently exchangeab...

AI Technical Summary

Problems solved by technology

[0006] The demand for extracting instance-level IFC sub-models is very large, but due to the high complexity, no relevant literature has been published; for example, extracting building components of a certain material, all equipment of a certain system, and all construction tasks of a certain day’s construction, etc. Application Scenario

The difficulty of the instance-level IFC sub-model extraction method is that each instance in the IFC model is related to each other through a relational entity instance, so if all associated instances are ignored during extraction, the information will be incomplete; otherwise, if all associated instances are extracted, then would contain a large number of unnecessary instances

For example, to extract an IFC model that satisfies the constraints (IfcTask, Name, "Civil Construction"), if only one instance of the IfcTask construction task named "Civil Construction" is extracted and all subtasks of the construction task are ignored, the extracted IFC The sub-model cannot fully describe all the information of the task; if all the sub-tasks, pre-tasks, and post-tasks associated with the "civil construction" task are proposed, redundant task nodes are included; it is even possible to extract all IfcTask instances, reaching Not for the purpose of filtering

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