Engineering change price full-conduction real-time estimation method and system fusing bim model and historical data

Abstract

The present application belongs to the technical field of data processing, and specifically relates to a method and system for full-conduction real-time estimation of engineering change price based on fusion of BIM model and historical data, which aligns and fuses a BIM model, engineering change information and historical engineering data to obtain change estimation data; determines a component set affected by the change based on the correlation between components in the BIM model; identifies the change type and matches full-conduction rules; constructs a full-conduction link of the change price based on the component set, the change estimation data and the full-conduction rules and estimates the change price in real time; updates the change price by re-calculating only the affected components in response to the change information; backfills the actual price result into the historical engineering data to correct subsequent estimation; updates the component attribute data of the BIM model, generates the full-conduction link of the change price and visually displays the same. The method can fuse multi-source engineering data and identify the change influence range, reduce the calculation cost by incremental re-calculation and improve the real-time performance and visualization of the change price estimation.

Description

Technical Field

[0001] This invention belongs to the field of data processing technology, and in particular relates to a method and system for real-time estimation of engineering change costs that integrates BIM models and historical data. Background Technology

[0002] During the implementation of engineering construction projects, design changes and engineering changes occur frequently, and the timely and accurate estimation of engineering change costs has a significant impact on project investment control. With the application of Building Information Modeling (BIM) technology in the field of engineering cost estimation, existing technologies typically rely on BIM models for quantity surveying. Cost estimators then manually determine the affected components and their scope based on engineering change information, and combine this with historical project data (such as historical change case data, price database data, and quota database data) to estimate the change costs.

[0003] However, existing technologies have at least the following technical problems: First, the scope and type of impact of changes rely on manual judgment. After an engineering change occurs, existing technologies typically rely on the engineering experience of cost estimators to manually determine which components are directly affected, which components are indirectly affected through component relationships in the BIM model, and what type of change the engineering change information belongs to and what processing method should be applied. There is a lack of technical means to automatically determine the set of components affected by the engineering change based on the component relationships, automatically identify the change type, and match the corresponding full transmission rules. This can easily lead to omissions or misjudgments, and it is difficult to unify the processing standards.

[0004] Second, there is a lack of automated means for the full transmission of change orders across all levels of the project. Change orders need to be transmitted and summarized level by level between components, sub-projects, and unit projects. Current technology usually requires cost estimators to calculate these changes manually at each level, which is a lagging process and makes it difficult to achieve real-time estimation of change orders based on the full transmission chain.

[0005] Third, the incremental recalculation capability after the change information is updated is lacking and the real-time performance is poor. After the engineering change information is updated, the existing technology usually needs to recalculate the price of all components. There is a lack of means to perform incremental recalculation only on the affected components. The calculation cost is large and the response time is long, making it difficult to adapt to the real-time update requirements in scenarios where changes occur frequently.

[0006] Fourth, historical engineering data lacks a feedback and correction loop, and the estimation results are presented in a single way. In existing technologies, there is a lack of backfilling and correction methods between historical engineering data and actual cost results, making it difficult to continuously improve subsequent change cost estimations using actual cost results. At the same time, the estimation results do not synchronously update the attribute data of corresponding components in the BIM model, and there is a lack of visualization of the entire change cost transmission chain, which is not conducive to engineering managers intuitively understanding the impact of changes.

[0007] Therefore, how to align and integrate BIM models, engineering change information, and historical engineering data, automatically determine the set of components affected by engineering changes based on component relationships, identify change types, match corresponding full transmission rules, and then construct a full transmission link for change costs to achieve real-time estimation of change costs, and perform incremental recalculation of affected components when change information is updated, and backfill the actual cost results into historical engineering data to correct subsequent estimates, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to provide a real-time estimation method and system for engineering change costs that integrates BIM models and historical data, in order to solve the technical problems existing in the prior art.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: Firstly, a real-time estimation method for the full transmission of engineering change costs, integrating BIM models and historical data, is provided, including the following steps: Step 1: Obtain the BIM model, engineering change information, and historical engineering data of the target project, and perform alignment and fusion processing on the BIM model, engineering change information, and historical engineering data to obtain change estimation data; Step 2: Based on the relationships between components in the BIM model, and according to the engineering change information, automatically identify the set of components affected by the engineering change from the change estimation data; Step 3: Identify the change type of the engineering change information and match the corresponding full transmission rule according to the change type; Step 4: Based on the component set, the change estimation data, and the matched full transmission rules, construct a full transmission link for change price, and estimate the change price corresponding to the engineering change in real time based on the full transmission link for change price; Step 5: In response to the update of the engineering change information, perform incremental recalculation only on the affected components in the component set, and update the change price based on the incremental recalculation result; Step 6: Obtain the actual price result corresponding to the changed price, fill the actual price result back into the historical project data, and correct the subsequent changed price estimate based on the backfilled historical project data; Step 7: Based on the change estimate data and the updated change price, update the attribute data of the corresponding component in the BIM model, generate a visualization of the entire change price transmission chain, and output the visualization data to the display terminal.

[0010] Preferably, the specific process of step 1 is as follows: Step 1-1: Feature Extraction: Extract feature vectors of each component from the BIM model. , including the The quantity of work for each component and the Type identifier of each component Extract feature vectors from historical engineering change cases from historical engineering data. , including the The amount of work done in each historical change case , No. Component type identifier for each historical change case , No. Change types in historical change cases , No. Actual settlement unit price for each historical change case ; Step 1-2: Data Alignment: Standardization is used to align the component quantities with historical case quantities, resulting in the... The standardized quantity of each component and the Standardized engineering quantities for each historical change case ; Steps 1-3: Calculate the similarity between the components that underwent engineering changes and each historical change case. ; Steps 1-4: Normalize the similarity to obtain the fusion weight of each historical change case. ; Steps 1-5: Perform fusion calculations on the BIM model, the engineering change information, and the historical engineering data to obtain change estimation data.

[0011] Preferably, the specific process of steps 1-5 is as follows: Let the set of change source components be denoted as ,in For each change source component in the set, the total number of change source components is [number]. Based on the BIM model and engineering change information, the revised engineering quantities are calculated. ; Based on historical engineering data and fusion weights, the calculation of the first... Unit price of each modified source component Based on the revised quantities and integrated unit price, calculate the first... The revised price benchmark for each modified source component Calculate the first The increase in change price corresponding to each changed component ; Integration yields the first Change estimation data for each change source component The change estimate data records of each change source component are combined into a change estimate data set. .

[0012] Preferably, the specific process of step 2 is as follows: Step 2-1: Construct component relationships: Extract the relationships between components from the BIM model and construct a component relationship matrix. ; Step 2-2: Extract the set of change source components: the set of change estimation data output from Step 1. In the process, extract the component number field from each record to form the change source component set. ; Steps 2-3: Correlation propagation to identify affected components: based on the set of change source components. Starting from the first component, the process propagates layer by layer along the component relationships to identify the components affected by the engineering changes, and is denoted as the [number]th component. The set of affected components added to the layer is ,when When propagation stops, the maximum propagation layer is denoted as . ; Steps 2-4: Output the set of affected components: Summarize the components of each layer to obtain the set of affected components. .

[0013] Preferably, the specific process of step 3 is as follows: Step 3-1: Change Feature Extraction: From the engineering change information, for the first... Extract change feature vectors from each change source component. The element is the first element of the source component of the change. Each change characteristic includes the changed location, the changed method, and the changed magnitude; Step 3-2: Change Type Identification: Based on the change feature vector , will the The change to a component source is identified as one type from a preset set of change types. The preset set of change types is... Based on the matching degree between the change characteristics and each preset change type, determine the first... Change type of each change source component ; Step 3-3: Full Transmission Rule Matching: The mapping relationship between preset change types and full transmission rules constitutes the full transmission rule set. It consists of the correspondence between change types and full transmission rules; based on the identified change types Match the corresponding full transmission rule from the full transmission rule set. The full propagation rules matched by each change source component are summarized into a full propagation rule matching result. .

[0014] Preferably, the specific process of step 4 is as follows: Step 4-1: Hierarchical Attribution Mapping: Based on the hierarchical structure of the BIM model, establish the hierarchical attribution relationships between components, sub-projects, and unit projects. Let the set of affected components be: in: : The set of affected components; : No. One affected component; Affected component index, ; Number of affected components; Establish attribution guidelines from components to sub-projects, and from sub-projects to unit projects: in: Component ownership indication; : No. One affected component; : No. Each sub-project; in: Instructions on the attribution of sub-projects; : No. Each sub-project; : No. Individual project units; Step 4-2: Calculation of component-level price: Determine the component-level price for each affected component after the change. The component-level price of the changed source component is its change price increment; the component-level price of the affected component that is not a changed source is determined by the associated impact. Step 4-3: Price Transmission at the Sub-project Level: Sum the prices of all components belonging to the same sub-project level to obtain the change price for each sub-project level. ; Step 4-4: Price Transmission at the Unit Project Level: Sum the prices of all sub-projects belonging to the same unit project level to obtain the change price at each unit project level. ; Steps 4-5: Construction of the Entire Transmission Link and Estimation of Total Cost: Construct the entire transmission link from the component level, sub-project level to the unit project level, and calculate the change price corresponding to engineering changes. .

[0015] Preferably, the specific process of step 5 is as follows: Step 5-1: Update Detection: Assume that the engineering change information occurs on the [number]th [number]th [number]. The latest update, the [number]th update after the [number]th [date]. The increment of the change price for each changed component is updated as follows: ; Step 5-2: Incremental Component Identification: From the set of affected components, identify components whose parameters have changed in this update as incremental components. in: : No. Incremental indication of each affected component; : No. One affected component; The incremental component set is as follows: , : Incremental component set; : No. Incremental indication of each affected component; Step 5-3: Determining the Incremental Recalculation Scope: Recalculation is performed only on incremental components and their associated components. The incremental recalculation scope is defined as follows: A set of components consisting of incremental components and their associated components; Step 5-4: Incremental Recalculation: Recalculate the component level price for the components within the incremental recalculation scope. Round of updates, number The component level price for each affected component is ; For components not included in the incremental recalculation, their component-level prices remain unchanged; Step 5-5: Tier Price Incremental Update: Based on the incremental recalculation results, update the prices for each tier to obtain the... After the first update The change price for each sub-project level is , No. After the first update The change price for each unit project level is , No. Price changes after the round of updates ; Steps 5-6: Convergence Judgment: When the change in price in multiple consecutive rounds of incremental recalculation is less than the preset convergence threshold, the entire transmission link of the change price is determined to be converged, and incremental recalculation is stopped.

[0016] Preferably, the specific process of step 6 is as follows: Step 6-1: Obtain the first Actual price result for each changed component ; Step 6-2: Historical Case Backfilling: Backfill the actual price result into the historical project data, construct a new historical change case and add it to the historical project data; Step 6-3: Update statistical parameters: Update the statistical parameters of the historical project data based on the backfilled historical project data; Step 6-4: Unit Price Correction: Based on the historical project data after backfilling, correct the integrated unit price used in subsequent estimations; Step 6-5: Subsequent estimation and correction: Based on the corrected fusion unit price, the following is obtained: Estimated cost of the modified component after correction .

[0017] Preferably, the specific process of step 7 is as follows: Step 7-1: Component attribute data update: Based on the change estimate data and the updated change price, update the attribute data of the affected components in the BIM model; Step 7-2: Generation of Visualized Data for the Entire Transmission Link: Based on the updated component attribute data, prices at each level, and the structure of the entire transmission link, generate visualized display data; Step 7-3: Display Data Output: Output the visualization data to the display terminal for display, so that the entire transmission link of the changed price and the price changes at each level are presented on the display terminal.

[0018] Secondly, it provides a real-time estimation system for engineering change costs that integrates BIM models and historical data, including: The data fusion module is used to acquire the BIM model of the target project, engineering change information and historical engineering data, and to perform alignment and fusion processing on the BIM model, the engineering change information and the historical engineering data to obtain change estimation data. The impact scope identification module is used to automatically identify the set of components affected by the engineering change from the change estimation data based on the relationship between the components in the BIM model and the engineering change information. The change type identification module is used to identify the change type of the engineering change information and match the corresponding full transmission rule according to the change type; The full transmission estimation module is used to construct a full transmission link for change price based on the component set, the change estimation data, and the matched full transmission rules, and to estimate the change price corresponding to the engineering change in real time based on the full transmission link for change price. The incremental update module is used to respond to the update of the engineering change information by performing incremental recalculation only on the affected components in the component set, and updating the change price based on the incremental recalculation result; The feedback correction module is used to obtain the actual price result corresponding to the changed price, fill the actual price result back into the historical project data, and correct the subsequent change price estimate based on the backfilled historical project data. The visualization module is used to update the attribute data of the corresponding components in the BIM model based on the change estimate data and the updated change price, and generate visualization display data of the entire transmission chain of the change price, and display the visualization display data.

[0019] The beneficial effects of this invention include: 1. By aligning and integrating BIM models, engineering change information, and historical engineering data, a unified data foundation was established, enabling subsequent change cost estimations to fully utilize component information in the BIM model and price information in historical engineering data, thus achieving effective integration and collaborative utilization of multi-source data.

[0020] 2. By automatically determining the set of affected components based on component association relationships, the subjectivity and inconsistency issues caused by manual judgment are avoided. The construction of the component association matrix fully considers the spatial adjacency and hierarchical affiliation relationships between components, and can systematically identify directly affected components as well as components indirectly affected through association relationships, ensuring the completeness and accuracy of the affected scope.

[0021] 3. By automatically identifying change types and matching corresponding full transmission rules, a standardized mapping relationship between change types and processing methods was established. The extraction of change feature vectors and the calculation of matching degrees enabled automated identification of change types, while the construction of the full transmission rule base enabled differentiated processing for different change types, making the full transmission calculation of change prices more accurate.

[0022] 4. A complete transmission estimation module was constructed, establishing a comprehensive transmission link from the component level, sub-project level to the unit project level, enabling automatic transmission and real-time aggregation of change order costs across all project levels. The establishment of hierarchical mapping relationships allows the transmission relationships between levels to be formally expressed and automatically executed, improving the efficiency and accuracy of change order cost estimation.

[0023] 5. Incremental recalculation during change information updates only recalculates the affected components and their related components, eliminating the need to recalculate all components. This reduces computational overhead, shortens response time, and adapts to real-time update requirements in scenarios with frequent changes. The introduction of a convergence determination mechanism ensures that incremental recalculation terminates within a reasonable range, avoiding unnecessary iterative calculations.

[0024] 6. The feedback correction module backfills the actual price results into the historical project data, constructing a feedback loop between historical data and actual results. The addition of new historical change cases enriches the sample of historical project data, the updating of statistical parameters enables dynamic adjustment of data distribution characteristics, and the correction of integrated unit prices allows for continuous improvement and optimization of subsequent estimates.

[0025] 7. The visualization module synchronously updates the change cost estimation results to the attribute data of the corresponding components in the BIM model and generates a visualized display of the entire transmission chain, enabling project managers to intuitively grasp the impact of changes and cost distribution, providing strong data support for investment control decisions. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the real-time estimation method for engineering change costs that integrates BIM models and historical data, as described in this invention. Figure 2 This is a schematic diagram of the hierarchical structure of the entire transmission link of the changed price in this invention; Figure 3 This is a schematic diagram of the visual display interface of the present invention. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1-3 The present invention will be further described in detail below: Example 1 The method and system of this invention take a target project as the processing object. This target project corresponds to a specific construction project, which can be various types of construction projects such as building construction projects, municipal infrastructure projects, and industrial plant projects. The target project has a complete BIM model as a digital representation. This BIM model contains the geometric information, attribute information, and spatial and logical relationships between all components constituting the project.

[0028] See Figure 1 As shown, the real-time estimation method for the full transmission of engineering change costs, which integrates BIM models and historical data, includes the following steps: Step 1: Obtain the BIM model, engineering change information, and historical engineering data of the target project, and perform alignment and fusion processing on the BIM model, engineering change information, and historical engineering data to obtain change estimation data.

[0029] The acquired BIM model is a 3D building information model, storing complete information on all components in the target project, including their geometric dimensions, material types, spatial locations, quantities, and hierarchical relationships. The project change information records all changes that occurred in the target project, with each change entry including fields such as change number, changed location, change method, change amount, reason for change, initiating party, and change time. Historical project data stores historical change cases related to the target project. These historical change cases originate from completed projects and include key information such as component types, change types, changed quantities, and actual settlement unit prices.

[0030] Step 2: Based on the relationships between components in the BIM model, and according to the engineering change information, automatically identify the set of components affected by the engineering change from the change estimation data.

[0031] Step 3: Identify the change type of the engineering change information and match the corresponding full transmission rule according to the change type; Step 4: Based on the component set, the change estimation data, and the matched full transmission rules, construct a full transmission link for change price, and estimate the change price corresponding to the engineering change in real time based on the full transmission link for change price; Step 5: In response to the update of the engineering change information, perform incremental recalculation only on the affected components in the component set, and update the change price based on the incremental recalculation result; Step 6: Obtain the actual price result corresponding to the changed price, fill the actual price result back into the historical project data, and correct the subsequent changed price estimate based on the backfilled historical project data; Step 7: Based on the change estimate data and the updated change price, update the attribute data of the corresponding component in the BIM model, generate a visualization of the entire change price transmission chain, and output the visualization data to the display terminal.

[0032] The specific process of step 1 is as follows: Step 1-1: Feature Extraction: In a specific embodiment, the feature vector of a component consists of quantity information and type identifier. The quantity information, depending on the component type, can be volume, area, length, or quantity, etc. The type identifier adopts a unified classification coding system, for example, coding according to the component classification specified in the "Standard for Measurement and Pricing of Building Engineering Quantities". Traverse all components in the BIM model, read the quantity field and type identifier field of each component, and combine them to form the feature vector of that component.

[0033] Specifically, feature vectors of each component are extracted from the BIM model: in: : No. The feature vectors of each component; : No. The quantity of a component represents the physical quantity of that component calculated according to national measurement rules. : No. Type identifier for each component; Component index ; The total number of components in the BIM model.

[0034] The feature vector of a historical change case contains four dimensions of information: the quantity of the component whose work was changed, the type identifier of the component, the type of change, and the actual settlement unit price. Change types are categorized according to a pre-defined set of change types, which includes common change types such as design changes, material replacements, process changes, dimensional adjustments, and increases / decreases in work quantity. Each historical change case record contains these four dimensions of information, which are then read and combined to form the feature vector of the historical change case.

[0035] Extracting feature vectors from historical engineering change cases from historical engineering data: in: : No. Feature vectors of historical change cases; : No. The workload of each historical change case; : No. Component type identifier for each historical change case; : No. The types of changes in a historical change case; : No. The actual settlement unit price for each historical change case; Index of historical change cases ; The number of historical change cases in historical engineering data.

[0036] Step 1-2: Data Alignment: Align the component quantities with historical case quantities to the same dimension and adopt standardization: in: : No. The quantity of work after standardization of each component; : No. The standardized engineering quantities for each historical change case; : No. The quantity of work for each component; : No. The workload of each historical change case; The average quantity of work completed in all historical change cases within the historical engineering data; : The standard deviation of the quantities of all historical change cases in the historical engineering data; Component index ; Index of historical change cases .

[0037] In a special case, when there are no historical change cases in the historical project data (i.e., the number of historical change cases is zero), standardization and weighted fusion are skipped, and the changes in quantity and benchmark unit price in the project change information are directly used as the calculation basis for each record in the change estimation data. In this case, the benchmark unit price can be obtained from the contract bill of quantities unit price library. If the unit price for the corresponding item is not found in the contract bill of quantities, the quota unit price specified in the pricing specification is used as an alternative. In another special case, when the quantities of all historical change cases are exactly the same, since there is no difference in the quantities, standardization is also skipped, and subsequent calculations are performed directly.

[0038] This means setting a safety net: when the number of historical change cases... Or, all historical change cases have the same amount of work done, resulting in At that time, the standardization and weighting fusion process is skipped, and the change in engineering quantity in the engineering change information is used directly. The benchmark unit price serves as the basis for calculating each record in the change estimate data.

[0039] Steps 1-3: Similarity Calculation: Similarity calculation considers three dimensions: the difference in quantities between the changed component and historical change cases, the matching of component types, and the matching of change types. The difference in quantities can be obtained by calculating the Euclidean distance using the standardized quantity values; the smaller the distance, the more similar the quantities. Component type matching is determined by comparing the type identifiers of the changed component with those of historical change cases. The maximum matching score is used when the type identifiers are completely identical; the intermediate value is used when the type identifiers belong to the same category but are not identical; and the minimum matching score is used when the type identifiers are completely different. The calculation method for change type matching is similar to component type matching, determined by comparing the change type field.

[0040] The formula for calculating the similarity between components that have undergone engineering changes and each historical change case is as follows: in: : Change of components and the first Similarity among historical change cases; : The quantity of work after standardizing the components; : No. The standardized engineering quantities for each historical change case; : Component type matching function, when the component type identifier is changed and matched with the first... When the component type identifiers of several historical change cases are the same, take... Otherwise take ; : Change the type identifier of the component; : No. Component type identifier for each historical change case; : Change type matching function, when the change type of the current project change matches the first... When the change types of historical change cases are the same, take... Otherwise take ; : The type of change in the current project change information; : No. The types of changes in a historical change case; Component number that underwent engineering changes; Index of historical change cases .

[0041] Steps 1-4: Weight Calculation The similarity is normalized to obtain the fusion weight of each historical change case: in: : No. The fusion weight of historical change cases; : Change of components and the first Similarity among historical change cases; : Change of components and the first Similarity among historical change cases; : Smoothing coefficient, taking the smallest positive number to avoid the denominator being zero; , Index of historical change cases; The number of historical change cases in historical engineering data.

[0042] Steps 1-5: Combine calculations to obtain change estimate data: The components affected by the engineering change can be one or more, and the set of change source components is denoted as . ,in This represents the total number of change source components. For each change source component in the set... Based on the BIM model and engineering change information, calculate the revised engineering quantities: in: : No. The quantity of work after the change of the source component; : No. The quantity of work done before the change of the source component; : No. The change in engineering quantity caused by the engineering change corresponding to a change source component can be positive or negative; : No. The number of the source component; Change the source component index. ; Change the total number of source components.

[0043] Based on historical engineering data and fusion weights, the calculation of the first... Unit price for merging a single source component: in: : No. The unit price for merging a single source component; : No. The fusion weight of historical change cases; : No. The actual settlement unit price for each historical change case; Index of historical change cases ; The number of historical change cases in historical engineering data; Change the source component index. .

[0044] Based on the revised quantities and integrated unit prices, calculate the... The revised price benchmark for each modified component: in: : No. The price benchmark after the change of the source component; : No. The quantity of work after the change of the source component; : No. The unit price for merging a single source component.

[0045] Calculate the first The increment in change price corresponding to each changed source component: in: : No. The incremental change price corresponding to each changed source component; : No. The change in engineering quantity caused by the engineering change corresponding to the change source component; : No. The unit price for merging a single source component; : No. The price benchmark after the change of the source component; : No. The quantity of work done before the change of the source component.

[0046] Synthesis of the first Change estimate data records for each change source component: in: : No. Change estimate data records for each change source component; : No. The number of the source component; : No. The change type corresponding to each change source component; : No. The quantity of work after the change of the source component; : No. The unit price for merging a single source component; : No. The price benchmark after the change of the source component; : No. The incremental change price corresponding to each changed source component.

[0047] Combine the change estimate data records of each change source component into a change estimate data set: in: Change estimate data is a collection of change estimate data records, with each record corresponding to a change source component; : No. Change estimate data records for each change source component; Change the source component index. ; Change the total number of source components.

[0048] The specific process of step 2 is as follows: Based on the relationships between components in the BIM model, the set of components affected by engineering changes is automatically identified from the change estimate data according to the engineering change information.

[0049] Step 2-1: Constructing Component Relationships: Extract the relationships between components from the BIM model. In a specific embodiment, the relationships between components include two types: spatial adjacency and hierarchical affiliation. Spatial adjacency refers to the spatial relationship where two components are in contact or close to each other in three-dimensional space, such as the connection between a wall and a floor slab, or the support relationship between a column and a beam. Hierarchical affiliation refers to the affiliation between a component and a sub-project or unit project. For example, a beam component belongs to the main structure sub-project, and this sub-project belongs to the entire building unit project.

[0050] Extract the relationships between components from the BIM model and construct a component relationship matrix: in: : Component association matrix, for OK A square matrix of columns; :member With components The association between components With components Take when there is a relationship Otherwise take ; , Component index ; The total number of components in the BIM model.

[0051] Step 2-2: Extract the Change Source Component Set: After constructing the component association matrix, extract the component number field from each record in the change estimation data set as the change source component set. Change source components refer to components whose quantities have directly changed, i.e., components corresponding to the change locations explicitly specified in the engineering change information. Starting from the change source component set, propagate layer by layer along the component association relationships to determine the components affected by the engineering change.

[0052] The change estimate data set output from step 1 In the process, extract the component number field from each record to form the set of change source components: in: : The set of change source components, that is, the set of component numbers that directly involve engineering changes; : No. The number of the source component; Change the source component index. ; Change the total number of source components.

[0053] Steps 2-3: The specific process of correlation propagation is as follows: The first layer of propagation uses all components in the set of change source components as the initial affected components. It queries the component correlation matrix to find all other components that are correlated with these change source components and includes these components in the newly added affected component set of the first layer. The second layer of propagation uses the newly added affected components of the first layer as a new starting point. It queries the component correlation matrix again to find components that are correlated with these components but have not yet been included in the affected scope and includes these components in the newly added affected component set of the second layer. Propagation continues in the same way for subsequent layers until a certain layer no longer generates new affected components. All components at each layer are summarized to obtain the final affected component set. In a specific embodiment, the depth of propagation layers can be set according to actual needs. When the project scale is large or the correlation is complex, the maximum propagation layer can be limited to 3 to 5 layers to control the computational load.

[0054] Change source component set Starting from this point, the process is propagated layer by layer along the component relationships to identify the components affected by the engineering changes. The set of affected components added to the layer is as follows: in: : No. The set of affected components added to the layer; : Index of candidate components; : No. Index of the affected components in the layer; :member With components Indicators of association between them; : No. The set of components affected by the layer; The layer index of the generated layer. ; Number of propagation layers.

[0055] when When propagation stops, the maximum propagation layer is denoted as . .

[0056] Steps 2-4: Output the set of affected components: By summarizing the components at each layer, we obtain the set of affected components: in: The set of affected components, including the component from which the change originated and components directly or indirectly related to it; : No. The set of components affected by the layer; Maximum propagation layers; Number of propagation layers .

[0057] The number of affected components is: in: Number of affected components; : The set of affected components.

[0058] Example 2 Building upon Example 1, in step 3, the change type identification stage, the change type of the engineering change information is identified, and the corresponding full transmission rule is matched according to the change type. First, change feature vectors are extracted from the engineering change information. These feature vectors include features such as the change location, change method, and change magnitude. The change location describes the specific location where the change occurred, such as floor number, axis position, or component number. The change method describes the specific form of the change, such as increasing dimensions, decreasing dimensions, material replacement, deleting components, or adding new components. The change magnitude describes the degree of the change, which can be an absolute value or a relative proportion.

[0059] Step 3-1: Feature Extraction From the engineering change information, regarding the first... Extract change feature vectors from each change source component: in: : No. The change feature vector of each change source component; : No. The first change source component Each change feature includes characteristics such as the location of the change, the method of the change, and the magnitude of the change. Change the source component index. ; Change the total number of source components; Change the feature number. ; Change the number of features.

[0060] Step 3-2: Identify the engineering change information into one type from a preset change type set based on the change feature vector. The preset change type set contains multiple preset change types, each corresponding to a standardized processing rule. In a specific embodiment, the preset change type set includes design changes, material replacements, process changes, dimensional adjustments, and increases / decreases in project quantity. Calculate the matching degree between the change feature vector and the standard feature vector of each preset change type, and select the preset change type with the highest matching degree as the identified change type. The matching degree can also be calculated using a weighted Euclidean distance method, and the weights of each feature can be adjusted according to the actual application scenario.

[0061] Based on the changed feature vector, the first The change to each change source component is identified as one type from a preset change type set. The preset change type set is: in: : Preset set of change types; : No. Preset change types; Change type number, ; : Preset number of change types.

[0062] Based on the matching degree between change characteristics and each preset change type, determine the first... Change types for each change source component: in: : No. The change type identified by each change source component; : with the The preset change type with the highest matching degree of the change source component; : No. The optimal change type sequence number corresponding to each change source component is the sequence number where the matching degree function takes the maximum value. : Change the feature vector and the first The matching degree function for the preset change type, the larger the value, the more similar the component feature is to the first one. The more similar the types; : No. The change feature vector of each change source component; Change the source component index. ; Change type number, .

[0063] Step 3-3: After identifying the change type, based on the preset mapping relationship between change types and full transmission rules, match the full transmission rules corresponding to the identified change type from the full transmission rule set. The full transmission rule library stores the transmission coefficients, adjustment parameters, and processing logic corresponding to various change types. Query the mapping table to find the full transmission rule corresponding to the current change type, and summarize the full transmission rules matched by each change source component into a full transmission rule matching result. In a specific embodiment, different change types correspond to different correlation influence coefficients. For example, the correlation influence coefficient for design changes is set to 0.35, for material replacement to 0.25, for process changes to 0.4, for size adjustments to 0.2, and for increases or decreases in project quantity to 0.15. The correlation influence coefficient is used to subsequently calculate the component-level price of affected components that are not change sources.

[0064] The mapping relationship between preset change types and full transmission rules constitutes the full transmission rule set: in: The full propagation rule set consists of the correspondence between change types and full propagation rules; : No. Preset change types; : with the Full transmission rules corresponding to the preset change types; Change type number, ; : Preset number of change types.

[0065] Based on the identified change type Match the corresponding full propagation rule from the full propagation rule set: in: : No. The full propagation rules matched by each change source component; : with the Full transmission rules corresponding to the preset change types; : No. The change type identified by each change source component; : No. Preset change types; Change the source component index. .

[0066] The full propagation rules matched by each change source component are summarized into the full propagation rule matching results: in: The full propagation rule matching result is the set of full propagation rules matched by each change source component; : No. The full propagation rules matched by each change source component; Change the source component index. ; Change the total number of source components.

[0067] See Figure 2 In the full transmission estimation stage of step 4, a full transmission link for change costs is constructed based on the component set, change estimation data, and matched full transmission rules. The change costs corresponding to engineering changes are then estimated in real time based on this link. First, the hierarchical relationship between components, sub-projects, and unit projects is established based on the hierarchical structure of the BIM model. In a specific embodiment, the hierarchical relationship is stored using a tree structure. The root node is the unit project, such as a building or a section of a project; intermediate nodes are sub-projects, such as foundation engineering, main structure engineering, decoration and finishing engineering, and electromechanical installation engineering; leaf nodes are specific components, such as beams, columns, and walls on a certain floor. Each component is associated with its corresponding sub-project, and each sub-project is associated with its corresponding unit project.

[0068] Step 4-1: Hierarchical Attribution Mapping: Based on the hierarchical structure of the BIM model, establish the hierarchical relationship between components, sub-projects, and unit projects. Let the set of affected components be: in: : The set of affected components; : No. One affected component; Affected component index, ; Number of affected components.

[0069] Establish attribution guidelines from components to sub-projects, and from sub-projects to unit projects: in: Component ownership indication, component Belongs to the sub-project Time to take Otherwise take ; : No. One affected component; : No. Each sub-project; Affected component index, ; Sub-project index ; : Number of sub-projects.

[0070] in: Sub-project attribution instructions, sub-project Belonging to unit project Time to take Otherwise take ; : No. Each sub-project; : No. Individual project units; Sub-project index ; Unit Project Index ; Quantity per unit of work.

[0071] Step 4-2: Component-Level Price Calculation: Determine the component-level price of each affected component after the change. The component-level price of the change source component (the component directly changed in Step 1) is its change price increment, which is directly read from the change estimate data record; the component-level price of affected components that are not change sources is determined by the associated impact. Specifically, the component-level price of non-change source components is equal to the sum of the products of the associated impact coefficient and the change price increment of each change source component, where the associated impact coefficient is obtained from the matched full transmission rules, and the change price increment of each change source component is obtained from the change estimate data record.

[0072] The component-level price is uniformly expressed as follows: in: : No. The component-level price of each affected component; : No. The increase in the price of each changed component; : No. The number of the source component; : No. The correlation influence coefficient of each non-change source affected component is determined by the matched full transmission rule; : No. The first change source component is related to the first The transmission correlation indication of each affected component is determined based on the component correlation matrix; , Change the source component index. ; Change the total number of source components; Affected component index, .

[0073] Step 4-3: Price Transmission at the Sub-project Level: Sum the prices of all components belonging to the same sub-project level to obtain the change price for each sub-project level. in: : No. Change fees at each sub-project level; Component ownership indication, component Belongs to the sub-project Time to take Otherwise take ; : No. The component-level price of each affected component; Affected component index, ; Number of affected components; Sub-project index .

[0074] For example, if a main structural sub-project has several affected beam and column components, the component-level prices of these components are added together to obtain the change price at the main structural sub-project level. The change prices for other sub-project levels are calculated in the same way.

[0075] Step 4-4: Price Transmission at the Unit Project Level: The change price for each sub-project belonging to the same unit project level is obtained by summing the prices at each level: in: : No. Change fees at the unit project level; Sub-project attribution instructions, sub-project Belonging to unit project Time to take Otherwise take ; : No. Change fees at each sub-project level; Sub-project index ; Quantity of sub-projects; Unit Project Index .

[0076] For example, a building may consist of multiple sub-projects such as main structure, decoration and renovation, and electromechanical installation. The change price of each sub-project level under the building is added together to obtain the change price of the unit project level.

[0077] Steps 4-5: Construction of the entire transmission link and estimation of total cost: Construct a complete transmission link from the component level, sub-project level to the unit project level, and calculate the change price (total transmission price) corresponding to engineering changes: in: The change fee corresponding to the engineering change, i.e., the total price of the entire project; : No. Change fees at the unit project level; Unit Project Index ; Quantity per unit of work.

[0078] The price at each level of the entire transmission link is calculated in real time based on the latest change estimate data; when the engineering change information is updated, only the corresponding price needs to be recalculated along the affected level, without recalculating all nodes in the entire link.

[0079] In another implementation, an uncertainty interval estimation mechanism for the change price is introduced. Based on the statistical distribution of the actual settlement unit prices of historical cases involved in the integration, the standard deviation of the integrated unit price is calculated, and then the confidence interval of the integrated unit price is determined. This interval is then propagated step by step along the component level, the sub-project level, and down to the unit project level, finally outputting the point estimate of the change price and its confidence interval.

[0080] First, based on the actual settlement unit price of historical cases involving integration, the standard deviation of the integration unit price is calculated, and a 95% confidence level is taken to obtain the confidence interval of the integration unit price.

[0081] Then, the unit price confidence interval is passed down level by level along the entire transmission link: Component level: The increment range of the change price for the component from which the change originates is equal to the change in quantity multiplied by the confidence interval of the integrated unit price; the price range of the affected components that are not from the change originates is equal to the correlation influence coefficient multiplied by the weighted sum of the increment ranges of the price for each component from which the change originates, with the lower and upper limits of the ranges summed separately.

[0082] Sub-project level: The lower limit and upper limit of the price range of each component belonging to the same sub-project are summed to obtain the change price range of that sub-project level.

[0083] Unit Project Level: The lower limit and upper limit of the price range of each sub-project belonging to the same unit project are summed to obtain the total price range of the unit project level.

[0084] Example 3 Based on Example 1 or Example 2, in the incremental update stage of step 5, in response to the update of engineering change information, incremental recalculation is performed only on the affected components in the component set, and the change price is updated based on the incremental recalculation result. First, it is checked whether the change information has been updated, specifically by comparing the version number or timestamp of the change information. When an update of the change information is detected, the components whose change parameters have changed in this update are identified as incremental components. Change parameters include quantity, unit price, correlation influence coefficient, etc., and a change in any parameter means that the component needs to be recalculated.

[0085] Incremental components are identified from the set of affected components, and recalculation is performed only on these incremental components and their associated components. The scope of incremental recalculation consists of the union of the incremental component and its associated components, where associated components are obtained by querying the component association matrix. The component-level price is recalculated for components within the scope of incremental recalculation; for components outside the scope, their component-level price remains unchanged. Based on the incremental recalculation results, the prices at each level are updated. The price at the sub-project level is updated by adding the price change caused by the incremental component to the original price, and the price at the unit project level is also updated accordingly. When the change in price over multiple consecutive rounds of incremental recalculation is less than a preset convergence threshold, the entire transmission chain of the change price is considered converged, and incremental recalculation is stopped.

[0086] Step 5-1: Update detection: Assume that the engineering change information occurs on the [number]th [day]. Next update To update the round sequence number ( This represents the initial state, i.e., the state after step 4 is completed. After the update, the... The increment of the change price for each changed component is updated as follows: .

[0087] Step 5-2: Incremental component identification: From the set of affected components, identify the components whose parameters have changed in this update as incremental components: in: : No. Incremental indication of each affected component, component When it is an incremental component, take Otherwise take ; : No. One affected component; Affected component index, .

[0088] The incremental component set is as follows: in: : Incremental component set; : No. Incremental indication of each affected component; : No. One affected component; Affected component index, ; Number of affected components.

[0089] Step 5-3: Determine the range of incremental recalculation: Recalculation is performed only on incremental components and their associated components. The scope of incremental recalculation consists of the union of the set of incremental components and their associated components: in: The incremental recalculation range is the set of components consisting of the incremental component and its associated components; : Incremental component set; Affected components that are related to incremental components; Incremental components; Component association indicator, component With components Take when there is a relationship Otherwise take (Association matrix with components in step 2) (The corresponding elements are consistent).

[0090] Step 5-4: Incremental recalculation: The component level price is recalculated for components within the incremental recalculation scope. For the first... Round of updates, number The component-level price for each affected component is as follows: in: : No. After the first update The component-level price of each affected component; : No. After the first update The increase in the price of each changed component; : No. The number of the source component; : No. The correlation influence coefficient of each non-modified source affected component; : No. The first change source component is related to the first Indication of conductive correlation of each affected component; , Change the source component index. ; Change the total number of source components; : No. One affected component; Affected component index, .

[0091] For components not included in the incremental recalculation, their component-level price remains unchanged: in: : No. After the first update The component-level price of each affected component; : No. Round (i.e., before the update) The component-level price of each affected component; : No. One affected component.

[0092] Step 5-5: Tier Price Increment Update: Based on the incremental recalculation results, update the prices at each level. After the first update The change fee for each sub-project level is as follows: in: : No. After the first update Change fees at each sub-project level; Component ownership indication; : No. After the first update The component-level price of each affected component; Affected component index, ; Sub-project index .

[0093] No. After the first update The change fee for each unit project level is as follows: in: : No. After the first update Change fees at the unit project level; Instructions on the attribution of sub-projects; : No. After the first update Change fees at each sub-project level; Sub-project index ; Unit Project Index .

[0094] No. The revised price after the round of updates (total price for all transmissions) is as follows: in: : No. The revised price after the round of updates (total price for all transmissions); : No. After the first update Change fees at the unit project level; Unit Project Index ; Quantity per unit of work.

[0095] Steps 5-6: Convergence determination: When the change in price over multiple consecutive incremental recalculations is less than a preset convergence threshold, the entire transmission chain of the changed price is considered converged, and incremental recalculation is stopped. The convergence criteria are as follows: in: : No. The revised price after the round of updates (total price for all transmissions); : No. The revised price after the round of updates (total price for all transmissions); : Preset convergence threshold.

[0096] In the feedback and correction phase of step 6, the actual price result corresponding to the changed price is obtained, and the actual price result is backfilled into the historical project data. Subsequent changed price estimates are then corrected based on the backfilled historical project data. The actual price result originates from the project settlement data. When the engineering change is completed and settled, the settlement amount is the actual price result. After obtaining this actual price result, it is backfilled into the historical project data, a new historical change case is constructed, and added to the historical project data.

[0097] Step 6-1: Obtaining the actual price result: Get the The actual price result corresponding to each changed source component: in: : No. The actual price result corresponding to each changed component is the actual settlement price after the engineering change is implemented; Change the source component index. ; Change the total number of source components.

[0098] Step 6-2: Historical Case Backfilling: The actual price result is then backfilled into the historical project data to construct a new historical change case, which is then added to the historical project data. The feature vector of the new historical change case is: in: : Feature vector of new historical change cases formed by backfilling; The workload of new historical change cases is taken from the first case. The quantity of work after the change of the source component ; The component type identifier for the new historical change case is taken from the type identifier of the changed component. ; The change type of the new historical change case is determined by the number of changes. Change type of each change source component ; The actual settlement unit price for new historical change cases is determined by the actual price result and the changed project quantity.

[0099] The actual settlement unit price for the new historical change case is: in: The actual settlement unit price for new historical change cases; : No. The actual price result corresponding to each changed source component; : No. The quantity of work after the change of the source component.

[0100] After backfilling, the number of historical change cases is updated as follows: in: Number of historical change cases after backfilling; Number of historical change cases before backfilling.

[0101] Step 6-3: Update statistical parameters: Based on the historical project data after backfilling, update the statistical parameters of the historical project data. The average project volume of historical cases after backfilling is: in: : Average amount of work done in historical cases after backfilling; Number of historical change cases after backfilling; : No. The workload for each historical change case (consistent with step 1, of which...) (This refers to the workload of the new backfill case). Index of historical change cases .

[0102] The standard deviation of the historical case quantities after backfilling is: in: : Standard deviation of historical case quantities after backfilling; Number of historical change cases after backfilling; : No. The workload of each historical change case; : Average amount of work done in historical cases after backfilling; Index of historical change cases .

[0103] Step 6-4: Unit Price Correction Based on the historical project data after backfilling, the integrated unit price used in subsequent estimates was corrected. The corrected integrated unit price is: in: : No. The corrected fusion unit price corresponding to each modified source component; : No. The fusion weight of historical change cases; : No. The actual settlement unit price for each historical change case; The fusion weight of new historical change cases is determined based on the backfilled case library, according to the weight calculation method in step 1. The actual settlement unit price for new historical change cases; Index of historical change cases ; Number of historical change cases before backfilling.

[0104] Step 6-5: Subsequent estimation and correction: Based on the corrected fusion unit price, the first... Estimated cost of the modified component after correction: in: : No. Estimated cost of the modified source component after correction; : No. The corrected fusion unit price corresponding to each modified source component; : No. The quantity of work after the change of the source component.

[0105] Correction mechanism explanation: Backfilled historical engineering data (including new historical change cases) Updated statistical parameters , With the corrected fusion unit price This serves as the data basis for subsequent engineering change estimates. When engineering changes occur again, the data alignment in step 1 and the unit price calculation in step 4 are both performed based on the backfilled historical engineering data, thereby achieving "correction of subsequent change price estimates based on the backfilled historical engineering data".

[0106] See Figure 3 In the visualization stage of step 7, the attribute data of the corresponding components in the BIM model are updated based on the change estimate data and the updated change price, and visualization data of the entire change price transmission chain is generated. The visualization data is then output to the display terminal for display. The attribute data of the affected components in the BIM model is updated. The updated attribute data includes the updated quantity of work, the updated unit price, and the estimated increase in change price. This data is written into the attribute fields of the corresponding components in the BIM model, so that the BIM model contains geometric information, original attributes, and change-related information. Visualization data is generated based on the updated component attribute data, prices at each level, and the entire transmission chain structure. The visualization data includes the following: graphical structural data of the entire transmission chain, showing the transmission relationship and amount flow between component levels, sub-project levels, and unit project levels; updated attribute data of each affected component, presented in table or label format; change prices at each sub-project level, displayed in bar chart or pie chart format; change prices at each unit project level; and the total change price corresponding to the engineering change.

[0107] Step 7-1: Component Attribute Data Update: Based on the change estimate data and the updated change price, update the attribute data of the affected components in the BIM model. The updated attribute data for each affected component are as follows: in: : No. Updated attribute data of each affected component in the BIM model; : No. The amount of work required to update each affected component; : No. The updated unit price for each affected component; : No. Estimated incremental change price for each affected component; Affected component index, .

[0108] When the The affected components are the change source components. At that time, the updated attribute data is consistent with the change estimate data record from step 1: in: : No. Updated attribute data of each affected component in the BIM model; : No. The quantity of work after the change of the source component; : No. The unit price for merging a single source component; : No. The increase in the price of each changed component; : No. One affected component; : No. The number of the source component for the change.

[0109] Step 7-2: Generation of Visualized Data for the Entire Transmission Link Based on the updated component attribute data, prices at each level, and the overall transmission link structure, a visual representation of the data is generated: in: Visualized data of the entire transmission chain; The graphical structure data of the entire transmission link includes component nodes, sub-project nodes, unit project nodes, and transmission edges between nodes; : No. Updated attribute data of each affected component in the BIM model; : No. Change fees at each sub-project level; : No. Change fees at the unit project level; : Change price corresponding to the engineering change (total price for all transfers, consistent with step 4); Affected component index, ; Number of affected components; Sub-project index ; Unit Project Index .

[0110] Step 7-3: Display Data Output: Output the visualization data to the display terminal for display, so that the entire transmission link of the changed price and the price changes at each level are presented on the display terminal.

[0111] A real-time estimation system for engineering change costs that integrates BIM models and historical data, including: The data fusion module is used to acquire the BIM model of the target project, engineering change information and historical engineering data, and to perform alignment and fusion processing on the BIM model, the engineering change information and the historical engineering data to obtain change estimation data. The impact scope identification module is used to automatically identify the set of components affected by the engineering change from the change estimation data based on the relationship between the components in the BIM model and the engineering change information. The change type identification module is used to identify the change type of the engineering change information and match the corresponding full transmission rule according to the change type; The full transmission estimation module is used to construct a full transmission link for change price based on the component set, the change estimation data, and the matched full transmission rules, and to estimate the change price corresponding to the engineering change in real time based on the full transmission link for change price. The incremental update module is used to respond to the update of the engineering change information by performing incremental recalculation only on the affected components in the component set, and updating the change price based on the incremental recalculation result; The feedback correction module is used to obtain the actual price result corresponding to the changed price, fill the actual price result back into the historical project data, and correct the subsequent change price estimate based on the backfilled historical project data. The visualization module is used to update the attribute data of the corresponding components in the BIM model based on the change estimate data and the updated change price, and generate visualization display data of the entire transmission chain of the change price, and display the visualization display data.

Claims

1. A real-time estimation method for engineering change costs that integrates BIM models and historical data, characterized in that: Includes the following steps: Step 1: Obtain the BIM model, engineering change information, and historical engineering data of the target project, and align and merge the BIM model, engineering change information, and historical engineering data to obtain change estimation data; Step 2: Based on the relationships between components in the BIM model, automatically identify the set of components affected by engineering changes from the change estimate data according to the engineering change information; Step 3: Identify the change type of the engineering change information and match the corresponding full transmission rule according to the change type; Step 4: Based on the component set, change estimate data, and the matched full transmission rules, construct the full transmission link of change price, and estimate the change price corresponding to the engineering change in real time based on the full transmission link of change price; Step 5: In response to updates to engineering change information, perform incremental recalculation only on the affected components in the component set, and update the change price based on the incremental recalculation results; Step 6: Obtain the actual price result corresponding to the change price, backfill the actual price result into the historical project data, and correct the subsequent change price estimate based on the backfilled historical project data; Step 7: Based on the change estimate data and the updated change price, update the attribute data of the corresponding components in the BIM model, generate a visualization of the entire change price transmission chain, and output the visualization data to the display terminal.

2. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 1, characterized in that, The specific process of step 1 is as follows: Step 1-1: Feature Extraction: Extract feature vectors of each component from the BIM model. , including the The quantity of work for each component and the Type identifier of each component Extract feature vectors from historical engineering change cases from historical engineering data. , including the The amount of work done in each historical change case , No. Component type identifier for each historical change case , No. Change types in historical change cases , No. Actual settlement unit price for each historical change case ; Step 1-2: Data Alignment: Standardization is used to align the component quantities with historical case quantities, resulting in the... The standardized quantity of each component and the Standardized engineering quantities for each historical change case ; Steps 1-3: Calculate the similarity between the components that underwent engineering changes and each historical change case. ; Steps 1-4: Normalize the similarity to obtain the fusion weight of each historical change case. ; Steps 1-5: Integrate and calculate the BIM model, engineering change information, and historical engineering data to obtain change estimate data.

3. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 2, characterized in that, The specific process of steps 1-5 is as follows: Let the set of change source components be denoted as ,in For each change source component in the set, the total number of change source components is [number]. Based on the BIM model and engineering change information, the revised engineering quantities are calculated. ; Based on historical engineering data and fusion weights, the calculation of the first... Unit price of each modified source component Based on the revised quantities and integrated unit price, calculate the first... The revised price benchmark for each modified source component Calculate the first The increase in change price corresponding to each changed component ; Integration yields the first Change estimation data for each change source component , The change type identified for the k-th change source component; the change estimate data records of each change source component are combined into a change estimate data set. .

4. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 3, characterized in that, The specific process of step 2 is as follows: Step 2-1: Construct component relationships: Extract the relationships between components from the BIM model and construct a component relationship matrix. ; Step 2-2: Extract the set of change source components: the set of change estimation data output from Step 1. In the process, extract the component number field from each record to form the change source component set. ; Steps 2-3: Correlation propagation to identify affected components: based on the set of change source components. Starting from the first component, the process propagates layer by layer along the component relationships to identify the components affected by the engineering changes, and is denoted as the [number]th component. The set of affected components added to the layer is ,when When propagation stops, the maximum propagation layer is denoted as . ; Steps 2-4: Output the set of affected components: Summarize the components of each layer to obtain the set of affected components. .

5. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 1, characterized in that, The specific process of step 3 is as follows: Step 3-1: Change Feature Extraction: From the engineering change information, for the first... Extract change feature vectors from each change source component. The element is the first element of the source component of the change. Each change characteristic includes the changed location, the changed method, and the changed magnitude; Step 3-2: Change Type Identification: Based on the change feature vector , will the The change to a component source is identified as one type from a preset set of change types. The preset set of change types is... Based on the matching degree between the change characteristics and each preset change type, determine the first... Change type of each change source component ; Step 3-3: Full Transmission Rule Matching: The mapping relationship between preset change types and full transmission rules constitutes the full transmission rule set. It consists of the correspondence between change types and full propagation rules; based on the identified change types, the corresponding full propagation rules are matched from the full propagation rule set. The full propagation rules matched by each change source component are summarized into a full propagation rule matching result. .

6. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 1, characterized in that, The specific process of step 4 is as follows: Step 4-1: Hierarchical Attribution Mapping: Based on the hierarchical structure of the BIM model, establish the hierarchical attribution relationships between components, sub-projects, and unit projects, and represent the set of affected components as follows: ; : The set of affected components; : No. One affected component; Affected component index, ; Number of affected components; Establish attribution guidelines from components to sub-projects, and from sub-projects to unit projects: in: Component ownership indication; : No. One affected component; : No. Each sub-project; in: Instructions on the attribution of sub-projects; : No. Individual project units; Step 4-2: Calculation of component-level price: Determine the component-level price for each affected component after the change. The component-level price of the changed source component is its change price increment; the component-level price of the affected component that is not a changed source is determined by the associated impact. Step 4-3: Price Transmission at the Sub-project Level: Sum the prices of all components belonging to the same sub-project level to obtain the change price for each sub-project level. ; Step 4-4: Price Transmission at the Unit Project Level: Sum the prices of all sub-projects belonging to the same unit project level to obtain the change price at each unit project level. ; Steps 4-5: Construction of the Entire Transmission Link and Estimation of Total Cost: Construct the entire transmission link from the component level, sub-project level to the unit project level, and calculate the change price corresponding to engineering changes. .

7. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 6, characterized in that, The specific process of step 5 is as follows: Step 5-1: Update Detection: Assume that the engineering change information occurs on the [number]th [number]th [number]. The latest update, the [number]th update after the [number]th [date]. The increment of the change price for each changed component is updated as follows: ; Step 5-2: Incremental Component Identification: From the set of affected components, identify components whose parameters have changed in this update as incremental components. in: : No. Incremental indication of each affected component; : No. One affected component; The incremental component set is as follows: ; Step 5-3: Determining the Incremental Recalculation Scope: Recalculation is performed only on incremental components and their associated components. The incremental recalculation scope is defined as follows: A set of components consisting of incremental components and their associated components; Step 5-4: Incremental Recalculation: Recalculate the component level price for the components within the incremental recalculation scope. Round of updates, number The component level price for each affected component is ; For components not included in the incremental recalculation, their component-level prices remain unchanged; Step 5-5: Tier Price Incremental Update: Based on the incremental recalculation results, update the prices for each tier to obtain the... After the first update The change price for each sub-project level is , No. After the first update The change price for each unit project level is , No. Price changes after the round of updates ; Steps 5-6: Convergence Judgment: When the change in price in multiple consecutive rounds of incremental recalculation is less than the preset convergence threshold, the entire transmission link of the change price is determined to be converged, and incremental recalculation is stopped.

8. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 1, characterized in that, The specific process of step 6 is as follows: Step 6-1: Obtain the first Actual price result for each changed component ; Step 6-2: Backfill the actual price result into the historical project data, construct a new historical change case and add it to the historical project data; Step 6-3: Update the statistical parameters of the historical project data based on the backfilled historical project data; Step 6-4: Based on the historical engineering data after backfilling, correct the integrated unit price used in subsequent estimations; Step 6-5: Based on the corrected fusion unit price, obtain the first... Estimated cost of the modified component after correction .

9. The real-time estimation method for engineering change costs integrating BIM model and historical data according to claim 1, characterized in that, The specific process of step 7 is as follows: Step 7-1: Based on the change estimate data and the updated change price, update the attribute data of the affected components in the BIM model; Step 7-2: Based on the updated component attribute data, prices at each level, and the entire transmission link structure, generate visual display data; Step 7-3: Output the visualization data to the display terminal for display, so that the entire transmission link of the price change and the price changes at each level can be presented on the display terminal.

10. A real-time estimation system for engineering change costs that integrates BIM models and historical data, used to implement the method of any one of claims 1-9, characterized in that, include: The data fusion module is used to acquire the BIM model, engineering change information and historical engineering data of the target project, and to align and fuse the BIM model, engineering change information and historical engineering data to obtain change estimation data. The impact scope identification module is used to automatically identify the set of components affected by engineering changes from the change estimate data based on the relationship between components in the BIM model and the engineering change information. The change type identification module is used to identify the change type of engineering change information and match the corresponding full transmission rules according to the change type; The full transmission estimation module is used to construct a full transmission link for change costs based on the component set, change estimation data, and the matched full transmission rules, and to estimate the change cost corresponding to the engineering change in real time based on the full transmission link for change costs. The incremental update module is used to respond to updates to engineering change information. It performs incremental recalculation only on the affected components in the component set and updates the change price based on the incremental recalculation results. The feedback correction module is used to obtain the actual price result corresponding to the change price, backfill the actual price result into the historical project data, and correct the subsequent change price estimate based on the backfilled historical project data. The visualization module is used to update the attribute data of the corresponding components in the BIM model based on the change estimate data and the updated change price, and generate a visualization display of the entire change price transmission chain, and then display the visualization display data.

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