Constraint solution algorithm-based parameterized construction drawing generation method

Abstract

The invention relates to the technical field of civil engineering informatization and automation design, in particular to a parameterized construction drawing generation method based on a constraint solution algorithm, and the method comprises the steps: defining a construction drawing foundation structure and variable parameters through an engineering design model embedded with a parameterized template; a parameter constraint relation set is generated in combination with geometric constraints, size constraints and logic constraints input by a user, constraint rules are converted into intermediate expressions through a formula analyzer, a syntax tree is constructed, and an executable parameter association rule set is generated through semantic verification. The auditing module verifies the drawing compliance based on the engineering specification database and generates a correction suggestion; and realizing cross-system data linkage between the multi-terminal collaborative interface and external BIM model parameter mapping. According to the method, the problems of detail loss and specification deviation in three-dimensional model projection are effectively avoided, and the drawing generation efficiency and the multi-specialty collaborative robustness are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of informatization and automated design in civil engineering, and particularly relates to a method for generating parametric construction drawings based on a constraint solving algorithm. Background Art

[0002] In the existing engineering drawing field, drawing generation mainly relies on secondary development of 3D modeling software, specifically using the sectional projection method or performing directional model conversion based on the AutoCAD platform. However, the above technical solutions have inherent defects: First, the core technology of the underlying graphics platform is subject to the architecture of foreign commercial software, and the lack of system autonomy and controllability leads to potential data security risks; Second, the structural features of the two-dimensional drawings generated by the conventional sectional projection are missing in the orthogonal direction of the axis. In particular, the three-dimensional spatial relationships such as the connection nodes of special-shaped components and concealed pipelines are difficult to be completely mapped to the two-dimensional view, resulting in the construction drawings not meeting the requirements of the engineering drawing specifications for the integrity of the structural expression; Third, the directional secondary development based on the AutoCAD platform is limited by the strong coupling relationship between the fixed drawing template and the specific model type. When the topological structure of the 3D model changes, the existing parametric drawing mechanism is prone to data breakage phenomena such as component misalignment and annotation inaccuracy, forcing developers to perform repetitive code adaptation for model iteration, significantly increasing the development and maintenance costs while reducing the robustness and scalability of the drawing generation system. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a method for generating parametric construction drawings based on a constraint solving algorithm, which solves the problems of detail loss, non-compliance with drawing specifications, and difficulty in drawing generation during the process of generating construction drawings from a 3D model in the forward design process.

[0004] To solve the above technical problems, the specific technical solution of the present invention is as follows: A method for generating parametric construction drawings based on a constraint solving algorithm provided by the present invention includes: Step S101, creating an engineering design model, wherein a parametric template is embedded in the engineering design model, and the parametric template defines the basic structure of the construction drawing and variable parameters associated with engineering requirements; Step S102, based on the constraint conditions input by the user, setting geometric associations, dimension associations, and logical associations for the variable parameters in the parametric template to generate a set of parameter constraint relationships; Step S103, parsing the association rules in the set of parameter constraint relationships through a formula parser to generate a set of parameter association rules recognizable by a constraint solving engine; Step S104: Input the parameter association rule set into a constraint solving engine for iterative calculation, and the constraint solving engine outputs parameter solutions that satisfy all constraint conditions based on a preset conflict resolution strategy; Step S105: Update the variable parameters in the parametric template according to the values in the parameter solutions, and map the updated parametric template to a two-dimensional construction drawing through a projection algorithm.

[0005] Furthermore, for the parametric construction drawing generation method based on a constraint solving algorithm according to the present invention, the parameter constraint relation set includes: Geometric constraints, which are used to define the relative positions and topological relationships of graphic elements in the engineering design model, and generate geometric association rules according to the basic structure of the parametric template; Dimension constraints, which are used to define the length, angle or proportional relationship of graphic elements according to the numerical range input by the user, and are converted into dimension association rules through the formula parser; Logical constraints, which are used to generate logical expressions based on the formulaic associations or conditional trigger rules between parameters, and the logical expressions are input into the constraint solving engine after being parsed by the formula parser.

[0006] Furthermore, for the parametric construction drawing generation method based on a constraint solving algorithm according to the present invention, the association rules in the parameter constraint relation set are parsed by a formula parser to generate a parameter association rule set recognizable by the constraint solving engine, including: Convert geometric association rules, dimension association rules and logical expressions into intermediate expressions in a unified format; Construct a syntax tree for the intermediate expression, and verify the compatibility between the syntax tree and the parametric template of the engineering design model through a semantic verification module; Generate a parameter association rule set executable by the constraint solving engine according to the syntax tree that passes the verification.

[0007] Furthermore, for the parametric construction drawing generation method based on a constraint solving algorithm according to the present invention, the creation of the parametric template includes: Extract general structural features from historical engineering drawings to generate an initial template library associated with the engineering design model; In response to the user's selection operation on the templates in the initial template library, load the selected template into the engineering design model, and add custom parameters associated with the template according to the engineering requirements input by the user.

[0008] Furthermore, for the parametric construction drawing generation method based on a constraint solving algorithm according to the present invention, it further includes: When the constraint solving engine detects a conflict in the generated set of parameter association rules, perform iterative backtracking based on the preset conflict parameter priorities in the engineering design model to determine the weight distribution of the conflict parameters; Generate an adjustable range for the conflict parameters according to the weight distribution, and feedback the adjustable range through the user interface of the engineering design model to trigger the user to correct the constraint relationship.

[0009] Further, in the method for generating a parametric construction drawing based on a constraint solving algorithm according to the present invention, the iterative backtracking includes: Determine the weight distribution rule in the conflict resolution strategy according to the conflict parameter priorities; Perform relaxation calculation on the conflict parameters based on the weight distribution rule, and feedback the calculation result to the parametric template in the engineering design model until the constraint solving engine outputs a conflict-free parameter solution.

[0010] Further, in the method for generating a parametric construction drawing based on a constraint solving algorithm according to the present invention, it further includes: Generate a version snapshot including the current parameter solution and constraint relationship based on the version management module of the engineering design model; In response to the user's selection operation of the historical version snapshot, load the parameter solution and constraint relationship in the version snapshot into the engineering design model, and re-trigger constraint solving and drawing generation.

[0011] Further, in the method for generating a parametric construction drawing based on a constraint solving algorithm according to the present invention, it further includes: Import the generated two-dimensional construction drawing into the review module of the engineering design model, and perform compliance verification on the geometric structures and parameters in the drawing according to the preset engineering specifications; When a violation is detected, generate a correction suggestion associated with the violation mark, and trigger a correction operation on the constraint relationship through the user interface of the engineering design model.

[0012] Further, in the method for generating a parametric construction drawing based on a constraint solving algorithm according to the present invention, it further includes: Receive a parameter adjustment instruction input by a remote user through the multi-terminal collaboration interface of the engineering design model, and the parameter adjustment instruction includes a target parameter identifier and an updated value; Dynamically update the constraint relationship based on the parameter adjustment instruction, and synchronously trigger parameter solution calculation and regeneration of the two-dimensional construction drawing through the constraint solving engine.

[0013] Further, in the method for generating a parametric construction drawing based on a constraint solving algorithm according to the present invention, it further includes: Associate and map the parametric template with an external BIM design model based on a multi - professional collaborative data interface, and establish a synchronization rule for the variable parameters in the parametric template and the parameters of the external BIM design model; When it is detected that the parameters of the external BIM design model change, automatically update the constraint relationship of the parametric template based on the synchronization rule, and trigger constraint solving and drawing generation.

[0014] Advantages of the present invention; Through the collaborative mechanism of the parametric template and the constraint solving engine, the present invention significantly improves the integrity and efficiency of construction drawing generation. The parametric template solidifies geometric topological relationships and parameter association rules based on engineering drawing specifications, and combines the dynamic parsing of geometric constraints, dimension constraints, and logical constraints to effectively avoid the problem of detail loss during the projection of 3D models. For example, the orthogonal projection and dynamic sectioning algorithms are used to completely express the structure of special - shaped nodes and the spatial relationship of hidden pipelines; the constraint solving engine, based on the iterative calculation of conflict resolution strategies and weight distribution rules, automatically processes parameter conflicts and generates compliant solutions, driving the projection algorithm to generate annotations and view expressions that conform to drawing specifications, solving the problems of manual annotation errors and specification deviations in traditional methods; the multi - terminal collaborative interface and the external model mapping rule achieve cross - system parameter linkage, combined with the differential storage and back - tracking mechanism of version snapshots, significantly reducing the repeated adaptation cost during model iteration, enhancing the robustness and real - time performance of drawing generation in multi - professional collaborative scenarios, and forming a closed - loop design process from parameter - driven to specification verification. Brief Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the drawings.

[0016] Figure 1 It is a flowchart of a parametric construction drawing generation method based on a constraint solving algorithm provided by an embodiment of the present invention. Detailed Embodiments

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. The technical solutions provided by each embodiment of the present invention are described in detail below in conjunction with the drawings. To better understand the objectives of the present invention, the present invention is further described in detail below.

[0018] Please refer to Figure 1 , a parametric construction drawing generation method based on a constraint solving algorithm provided by the present invention includes: Step S101, create an engineering design model, in which a parametric template is embedded, and the parametric template defines the basic structure of the construction drawing and variable parameters associated with engineering requirements; Step S102, based on the constraint conditions input by the user, set geometric association, dimension association, and logical association for the variable parameters in the parametric template to generate a set of parameter constraint relationships; Step S103, parse the association rules in the set of parameter constraint relationships through a formula parser to generate a set of parameter association rules recognizable by a constraint solving engine; Step S104, input the set of parameter association rules into the constraint solving engine for iterative calculation, and the constraint solving engine outputs parameter solutions that satisfy all constraint conditions based on a preset conflict resolution strategy; Step S105, update the variable parameters in the parametric template according to the values in the parameter solutions, and map the updated parametric template to a two-dimensional construction drawing through a projection algorithm.

[0019] The process of creating an engineering design model requires constructing a digital model framework including a parametric template. The construction of the parametric template is based on the structured analysis of historical engineering drawings. Through a feature extraction algorithm, general structural features in the drawings (such as the axis intersection coordinates of beam-column joints and the topological relationship of pipeline layouts) are identified to generate an initial template library associated with the engineering design model. The templates in the template library are stored in a structured data format, including fields such as parameter names, parameter types, value ranges, and association rules. After the user selects a basic template from the template library through a graphical user interface, custom parameters associated with the template can be added based on the current engineering requirements (for example, defining the column section diameter as an interval parameter and binding it to the geometric attribute field of the template), and finally a parametric template embedded in the engineering design model is formed, which serves as the core carrier for subsequent constraint setting and drawing generation.

[0020] When setting parameter association relationships based on the constraint conditions input by the user, three types of association rules, namely geometric constraints, dimension constraints, and logical constraints, need to be defined separately. Geometric constraints are input through a graphical user interface and are used to limit the relative positions and topological relationships of graphical elements (such as setting the alignment tolerance of the centerlines of adjacent column members and the minimum clear distance constraint between pipes and the bottom of beams), and geometric association rules are generated based on the basic structure of the parametric template; dimension constraints define the length, angle, or proportional relationships of graphical elements based on the numerical ranges input by the user (such as the parameter interval of the slab thickness and the proportional relationship between the beam span and the slab thickness), and are converted into dimension association rules after format verification; logical constraints describe the dynamic associations between parameters through formulaic expressions or conditional trigger rules (such as the rule to trigger column section adjustment when the floor height exceeds a threshold), and logical expressions are generated. After the above three types of constraint conditions are unified in format and verified for integrity, they are integrated into a set of parameter constraint relationships including constraint types, acting parameters, and expression data, which serve as the input data for subsequent parsing and solving.

[0021] When parsing the set of parameter constraint relationships through a formula parser, three sub-steps of format conversion, syntax tree construction, and semantic verification need to be completed in sequence. First, the geometric association rules, dimension association rules, and logical expressions are uniformly converted into intermediate expressions (such as structured data based on JSON or XML) to eliminate the format differences of different constraint types; second, the intermediate expressions are hierarchically parsed through a syntax tree construction algorithm to generate an abstract syntax tree reflecting the dependency relationships between parameters (the tree nodes include operators, parameter identifiers, and constant values); finally, the semantic verification module traverses the syntax tree nodes to verify the parameter existence (parameters involved in the implementation of the constraints have been defined in the parametric template), type matching (for example, length parameters cannot be directly operated with angle parameters), and value range compliance (for example, the slab thickness parameter needs to be within the set interval). The syntax tree that passes the verification is serialized into a set of parameter association rules recognizable by the constraint solving engine (such as the matrix form of a system of linear equations or a piecewise function instruction set).

[0022] After the set of parameter association rules is input into the constraint solving engine, the engine performs iterative calculations based on a preset conflict resolution strategy. When the engine is initialized, it loads the priorities of conflict parameters (such as the priority of structural safety parameters is higher than that of economic parameters). When conflicts are detected in the rule set (such as contradictory value requirements for the same parameter by different constraint rules), weight is assigned to the conflict parameters according to the priorities (parameters with high priorities retain strict constraints, and parameters with low priorities relax the constraint conditions), and the value ranges of the conflict parameters are adjusted through relaxation calculations (such as allowing the dimensions of secondary members to float within a certain range). The calculation results are fed back to the parametric template of the engineering design model in real time to drive the dynamic update of the template parameters. The iterative process continues until a parameter solution that satisfies all constraint conditions is output or a preset iteration count threshold is reached (if not converged, the adjustable range of the conflict parameters is generated and the user is prompted to correct the constraint conditions).

[0023] After updating the variable parameters in the parametric template according to the parameter solution, the updated template is mapped to a two-dimensional construction drawing through the projection algorithm. The projection algorithm is based on the principle of orthogonal projection, combined with the geometric structure and size rules defined in the parametric template, to automatically generate the main view and select the cutting position according to the component density to generate the section view (such as the local detail at the beam-column node). The annotation module generates dimension annotations based on the numerical values in the parameter solution (such as converting the column section diameter parameter value into annotation text and associating it with the parameter identifier), and finally outputs the two-dimensional construction drawings in DWG format. The generated drawings are recorded as version snapshots including the current parameter solution, constraint relationships and projection parameters by the version management module (using differential storage technology to only save parameter changes), which supports users to trace back the historical status and re-trigger the constraint solution and drawing generation process.

[0024] Specifically, in the parametric construction drawing generation method based on the constraint solving algorithm described in the present invention, the parameter constraint relationship set includes: Geometric constraints, used to define the relative positions and topological relationships of graphic elements in the engineering design model, and to generate geometric association rules based on the basic structure of the parametric template; Dimension constraints, used to define the length, angle or proportional relationship of graphic elements according to the numerical range input by the user, and converted into dimension association rules by the formula parser; Logical constraints are used to generate logical expressions based on the formulated associations between parameters or conditional triggering rules. The logical expressions are parsed by the formula parser and then input into the constraint solving engine.

[0025] The geometric constraints in the parameter constraint relationship set are input through the graphical user interface and are used to limit the spatial position relationship and topological structure of the graphic elements in the engineering design model. In specific implementation, users can define relative position constraints for the basic structures in the parametric template (such as beam-column nodes and pipeline layouts), such as setting the centerline alignment tolerance of adjacent column components to ±5mm, or the minimum clearance constraint between the pipeline and the bottom of the beam to 200mm; at the same time, topological relationship constraints can be defined, such as requiring that two pipelines must not cross in space, or that the beam component must completely cover the top area of the column component. The above constraints generate geometric association rules based on the geometric features of the parametric template, such as describing the centerline alignment relationship through coordinate difference equations, or describing the inclusion relationship between components through spatial area coverage conditions, providing a spatial logical basis for subsequent constraint solving.

[0026] The setting of dimensional constraints depends on the numerical range and proportional relationship input by the user. Users can use the numerical input box or slider tool to set specific intervals for the length, angle or proportional parameters of graphic elements (such as limiting the plate thickness parameter to 120mm to 150mm), or define the proportional relationship between parameters (such as the ratio of beam span to plate thickness is 1.2:1). After format verification (such as excluding non-numerical input and verifying the rationality of the ratio), these input numerical ranges and proportional relationships are converted into dimensional association rules. For example, the plate thickness interval is converted into an inequality constraint (120mm≤plate thickness≤150mm), and the proportional relationship is converted into a linear equation (beam span = 1.2×plate thickness). After the dimensional association rules are processed by the formula parser, they form a numerical calculation basis that can be recognized by the constraint solving engine, so that the dimensional parameters of the graphic elements meet the engineering design requirements.

[0027] Logical constraints describe the dynamic association between parameters through formulaic expressions or conditional trigger rules. Users can define the formulaic association between parameters through the expression input box (such as column section diameter = floor height / 6+250mm), or set conditional trigger rules (such as when the floor height ≥4.0m, automatically activate the constraint that the length of the column stirrup reinforcement zone is ≥500mm). The above logical relationship is generated after syntax verification (such as checking the legality of operators and the validity of parameter identifiers). For example, the conditional trigger rule is converted into a piecewise function form (when the floor height ≥4.0m, the length of the reinforcement zone = 500mm; otherwise the length of the reinforcement zone = 300mm). The logical expression is parsed by the formula parser into an instruction set that can be executed by the constraint solving engine (such as conditional judgment statements or piecewise calculation rules), which is used to drive the dynamic adjustment between parameters and meet the multi-scenario parameter linkage requirements in engineering design.

[0028] Geometric constraints, dimensional constraints and logical constraints together constitute a set of parameter constraint relationships, which limit the value logic of variable parameters in parametric templates from three dimensions: spatial position, numerical value and dynamic association. Geometric constraints ensure that the spatial layout of graphic elements meets topological requirements, dimensional constraints limit the numerical range and proportional relationship of parameters, and logical constraints describe the conditional triggering and dynamic adjustment rules between parameters. The three are integrated into a structured data set through format unification and integrity verification, providing a comprehensive input basis for the subsequent rule conversion of the formula parser and the iterative calculation of the constraint solving engine, and jointly supporting the integrity and executability of the parametric construction drawing generation method.

[0029] Specifically, the parametric construction drawing generation method based on the constraint solving algorithm of the present invention parses the association rules in the parameter constraint relationship set by a formula parser to generate a parameter association rule set that can be recognized by the constraint solving engine, including: Convert geometric association rules, dimension association rules and logical expressions into intermediate expressions in a unified format; Construct a syntax tree for the intermediate expression, and verify the compatibility between the syntax tree and the parametric template of the engineering design model through a semantic verification module; Generate a set of parameter association rules executable by the constraint solving engine based on the syntax tree passed the verification.

[0030] The parsing process of the formula parser for the set of parameter constraint relationships includes three consecutive technical processes, namely intermediate expression conversion, syntax tree construction, and semantic verification, and finally generates a set of parameter association rules executable by the constraint solving engine.

[0031] In the intermediate expression conversion process, geometric association rules, dimension association rules, and logical expressions need to be unified into a structured data format. For geometric association rules (such as the alignment tolerance of the centerlines of adjacent columns is ±5mm), they are converted into numerical expressions such as "|X1 - X2| ≤ 5mm" through coordinate difference equations; dimension association rules (such as the ratio relationship between beam span and slab thickness) are converted into linear equations such as "beam span = 1.2 × slab thickness"; logical expressions (such as when the floor height ≥ 4.0m, column stirrup encryption is triggered) are converted into piecewise functions such as "when H ≥ 4.0m, the encrypted zone length = 500mm; otherwise = 300mm". The above different types of rules are normalized in format (such as using JSON or XML structured data) to form intermediate expressions in a unified format, eliminating the differences in the expression forms of the original constraint rules and providing a standardized input for subsequent parsing.

[0032] In the syntax tree construction process, a hierarchical structure reflecting parameter dependency relationships is generated based on the intermediate expression. Through syntax parsing algorithms (such as recursive descent parsing), lexical analysis and syntax analysis are performed on the intermediate expression, and the expression is decomposed into basic units such as operators, parameter identifiers, and constant values, and an abstract syntax tree (AST) is constructed according to the operation precedence and logical relationships. For example, for the intermediate expression "beam span = 1.2 × slab thickness", the root node of the syntax tree is the equal sign operator, the left child node is the parameter identifier "beam span", the right child node is the multiplication operator, and its left and right child nodes are the constant "1.2" and the parameter identifier "slab thickness" respectively. The syntax tree clearly presents the calculation logic and dependency order between parameters in a tree structure, providing a structured analysis object for subsequent semantic verification.

[0033] In the semantic verification step, the compatibility between the syntax tree and the parameterized template is verified through the semantic verification module. The verification content includes: verification of parameter existence (checking whether the parameter identifiers involved in the syntax tree are defined in the variable parameter list of the parameterized template, for example, confirming that "beam span" and "plate thickness" are the parameters bound by the template), type matching verification (ensuring that the types of parameters participating in the same operation are consistent, such as length parameters cannot be directly added to angle parameters), and value range verification (verifying whether the values of parameters in the syntax tree conform to the set range of the template, such as whether the plate thickness parameter is within the allowable range of 120mm to 150mm). If an incompatibility problem is found during verification (such as undefined parameters or type errors), the system generates an error prompt and terminates the parsing process; if the verification passes, it is confirmed that the parameter definitions and constraint rules of the syntax tree and the parameterized template are fully compatible.

[0034] Generate a set of parameter association rules executable by the constraint solving engine based on the syntax tree that has passed the verification. According to the structural characteristics of the syntax tree, convert it into an instruction format supported by the constraint solving engine: for a syntax tree in the form of a linear equation system (such as beam span = 1.2 × plate thickness), convert it into a linear constraint instruction in matrix form (Ax = b, where A is the coefficient matrix and b is the constant vector); for a syntax tree in the form of a piecewise function (such as the encryption zone length rule triggered by floor height), convert it into a set of conditional judgment and piecewise calculation instructions. The generated set of parameter association rules completely retains the logical relationship and calculation requirements of the original constraint rules, enabling the constraint solving engine to accurately identify and execute the association calculations between parameters, providing an operable input basis for subsequent iterative solutions.

[0035] Specifically, for the method for generating parametric construction drawings based on the constraint solving algorithm described in the present invention, the creation of the parameterized template includes: Extract general structural features from historical engineering drawings to generate an initial template library associated with the engineering design model; In response to the user's selection operation on the template in the initial template library, load the selected template into the engineering design model and add custom parameters associated with the template according to the engineering requirements input by the user.

[0036] The creation process of the parameterized template includes two consecutive technical steps: extraction of general structural features and construction of the template library, and user selection of the template and addition of custom parameters, aiming to form the core carrier supporting the generation of construction drawings through historical data reuse and personalized expansion.

[0037] The extraction of general structural features and the construction of the template library are based on the structured analysis of historical engineering drawings. First, collect historical engineering drawings (including standard format files such as DXF and DWG, or system-customized sketch templates), and identify the general structural features in the drawings through feature extraction algorithms (such as the identification of axis intersection points based on computer vision and the extraction of pipeline connection relationships based on topological analysis), such as the axis intersection coordinates of beam-column joints, the spatial avoidance rules of pipeline layouts, and the geometric dimension thresholds of standard components. After the extracted features are de-duplicated and normalized (such as unifying the unit system and merging similar topological structures), an initial template library associated with the engineering design model is generated. Each template in the template library is stored in a structured data format, including basic structure fields (such as geometric topological relationships and standard dimension parameters) and extended fields (such as parameter types and value ranges that allow customization), providing a data basis for subsequent template selection and parameter extension.

[0038] The process of users selecting templates and adding custom parameters is implemented through a graphical user interface. Users browse the initial template library through the interface and select a matching basic template according to the current engineering requirements (such as building type and component type) (for example, the beam-column template of the standard floor of a high-rise building or the underground pipeline layout template). After the system responds to the selection operation, the selected template is loaded into the engineering design model, and the basic structure of the template (such as axis grid and node connection rules) is automatically embedded in the model framework as the reference structure for drawing generation. Based on specific engineering requirements (such as adjusting component dimension thresholds and adding material property parameters), users add custom parameters to the template through the parameter input interface (for example, adding a "cantilever length" parameter to the beam-column template and setting its value range from 1000mm to 2000mm, or binding the "concrete strength grade" parameter to the material property field of the template). The added custom parameters establish an association relationship with the basic structure fields of the template (such as the cantilever length parameter is bound to the geometric attributes of the beam component), and finally form a parameterized template including the basic structure and personalized parameters, which serves as the core data carrier for subsequent constraint setting and drawing generation.

[0039] The above two steps combine historical data reuse and personalized extension, which not only ensures the engineering applicability of the template (general structure based on mature design experience) but also supports the flexibility of the design process (meeting specific engineering requirements through custom parameters), providing a reusable and extensible template basis for the parametric construction drawing generation method.

[0040] Specifically, the parametric construction drawing generation method based on the constraint solving algorithm described in the present invention further includes: When the constraint solving engine detects a conflict in the generated set of parameter association rules, perform iterative backtracking based on the preset conflict parameter priorities in the engineering design model to determine the weight distribution of the conflict parameters; An adjustable range of the conflicting parameters is generated according to the weight distribution, and the adjustable range is fed back through the user interface of the engineering design model to trigger the user to modify the constraint relationship.

[0041] When the constraint solving engine detects a conflict in the parameter association rule set (i.e., different constraint rules have contradictory requirements for the value of the same parameter, such as the dimensional constraint requiring the beam span to be 6000mm, while the geometric constraint requires the beam span to be no more than 5800mm), the system performs an iterative backtracking process based on the conflict parameter priorities preset in the engineering design model to determine the weight distribution of the conflicting parameters. The conflict parameter priorities are usually defined in the initialization phase of the engineering design model and stored in the form of a parameter priority table. For example, the priority of structural safety-related parameters (such as column bearing capacity and node connection strength) is set higher than that of economic parameters (such as concrete dosage and component size), or the parameter priority order is customized according to specific engineering requirements (such as setting the priority of pipeline clearance parameters higher than beam span parameters).

[0042] During the iterative backtracking process, the constraint solving engine assigns weights to the parameters involved in the conflict according to the conflict parameter priority table. The weight assignment rules are directly related to the priority: high-priority parameters retain strict constraints (such as the column section diameter must meet the minimum bearing capacity requirements), and low-priority parameters relax constraints (such as allowing the beam span to float within a certain range). For example, when the column section diameter conflicts with the beam span parameter, if the column section diameter has a higher priority, the engine retains its constraints (such as D≥600mm) and relaxes the constraints of the beam span parameters (such as adjusting the original constraint L≤5800mm to L≤6200mm). The engine continuously adjusts the weight values of low-priority parameters through iterative calculations, gradually expanding its acceptable value range until the constraints of the conflicting parameters are no longer contradictory.

[0043] Based on the weight distribution results, the system generates an adjustable range for the conflicting parameters. The adjustable range is generated based on the constraints after relaxation calculations. For example, the allowed range of the beam span parameter after relaxation is 5800mm to 6200mm, or the allowed range of the concrete content parameter is 90% of the original lower limit to 110% of the original upper limit. The generated adjustable range is fed back through the user interface of the engineering design model, usually in the form of highlighting the conflicting parameters, displaying the current value of the parameter and the adjustable range (such as "Current value of beam span: 6000mm, adjustable range: 5800-6200mm"), and accompanied by a description of the cause of the conflict (such as "Conflict with column section diameter constraint, it is recommended to adjust the beam span to an acceptable range").

[0044] The adjustable range of the user interface feedback is used to trigger the user to correct the constraint relationship. The user can, according to the feedback information, adjust the constraint conditions of the conflict parameters through the interface (such as modifying the original constraint of the beam span L≤5800mm to L≤6200mm), or adjust the constraint rules of other associated parameters (such as reducing the priority of the concrete consumption parameter to further relax its constraint). After the user's correction operation is completed, the system regenerates the parameter constraint relationship set and triggers the iterative calculation of the constraint solving engine until a conflict-free parameter solution is output.

[0045] The above process forms a closed-loop mechanism for conflict resolution through the weight assignment with preset priorities, the relaxation calculation of iterative backtracking, and the conflict feedback of the user interface, which not only ensures the strictness of the constraints of the core parameters (such as structural safety parameters), but also guides the user to make reasonable corrections through the adjustable range, realizing the compatibility of the parameter association rule set and the feasibility of engineering design.

[0046] Specifically, for the parametric construction drawing generation method based on the constraint solving algorithm described in the present invention, the iterative backtracking includes: Determining the weight assignment rule in the conflict resolution strategy according to the priority of the conflict parameters; Performing a relaxation calculation on the conflict parameters based on the weight assignment rule and feeding the calculation result back to the parametric template in the engineering design model until the constraint solving engine outputs a conflict-free parameter solution.

[0047] The iterative backtracking process is the core mechanism for the constraint solving engine to handle parameter conflicts, including two consecutive steps of determining the weight assignment rule and feedback of the relaxation calculation. By dynamically adjusting the constraint conditions of the conflict parameters, the output of a conflict-free parameter solution is ultimately realized.

[0048] The determination of the weight assignment rule is based on the preset priority of the conflict parameters in the engineering design model. The priority of the conflict parameters is usually stored in the form of a priority table in the engineering design model, and the priority order of each parameter is clearly defined in the table (such as the priority of the structural safety parameter "column section diameter" is higher than that of the economic parameter "beam span", or the priority of the pipeline net distance parameter is higher than that of the component size parameter). When the constraint solving engine detects a conflict (such as the geometric constraint requires the beam span ≤ 5800mm, while the dimension constraint requires the beam span = 6000mm), it first extracts the parameters involved in the conflict (such as the beam span and column section diameter), and queries the priority table to determine the priority level of each parameter. Based on the priority level, the engine generates a weight assignment rule: the high-priority parameter retains the original constraint condition (such as the column section diameter must be ≥ 600mm to meet the bearing capacity requirement), and the constraint condition of the low-priority parameter needs to be relaxed (such as the original constraint of the beam span ≤ 5800mm is adjusted to ≤ 6200mm), to achieve the strictness of the constraints of the core parameters.

[0049] The relaxation calculation based on the weight assignment rule is achieved by gradually adjusting the value range of the conflict parameters. The engine relaxes the constraint conditions of the low-priority parameters. For example, the upper limit of the beam span is gradually relaxed from 5800 mm to 5900 mm, 6000 mm, 6100 mm, 6200 mm. After each adjustment, the parameter solution is recalculated and verified whether it meets all the constraint conditions. During the relaxation calculation process, the engine real-time feeds back the adjusted parameter values to the parametric template of the engineering design model, driving the dynamic update of the corresponding parameters in the template (such as when the beam span parameter value is updated from 5800 mm to 6000 mm, the geometric dimensions of the beam members in the template are adjusted synchronously). The iterative backtracking continues until the constraint solving engine outputs a parameter solution that meets all the constraint conditions (such as beam span = 6000 mm, column section diameter = 600 mm, and there is no contradiction between the two constraint conditions), or reaches the preset maximum number of iterations (if not converged, prompt the user to intervene and correct the constraint relationship).

[0050] The above two steps form a dynamic adjustment mechanism for conflict parameters through priority-driven weight assignment and step-by-step relaxation calculation feedback. The weight assignment rule realizes the strictness of the constraints of the core parameters. The relaxation calculation balances the conflicts by gradually relaxing the value range of the parameters, and finally realizes the compatibility of the parameter association rule set, providing a conflict-free parameter solution basis for the generation of subsequent two-dimensional construction drawings.

[0051] Specifically, the parametric construction drawing generation method based on the constraint solving algorithm described in the present invention further includes: Based on the version management module of the engineering design model, generate a version snapshot including the current parameter solution and constraint relationship; In response to the user's selection operation of the historical version snapshot, load the parameter solution and constraint relationship in the version snapshot into the engineering design model, and re-trigger the constraint solving and drawing generation.

[0052] The version management module of the engineering design model realizes the state traceability and rapid iteration of the design process by generating version snapshots and responding to the historical snapshot loading operation, specifically including two technical steps: version snapshot generation and historical snapshot loading.

[0053] The generation of version snapshots is automatically triggered by the version management module after the parameter solution is output. Each time the constraint solving engine outputs a conflict-free parameter solution and completes the generation of two-dimensional construction drawings, the module extracts the core status data of the current engineering design model, including the specific values of the parameter solution (such as column section diameter 650mm, beam span 6200mm, etc.), the rule set of constraint relationships (such as alignment tolerance of geometric constraints, proportional relationship of dimensional constraints, conditional expressions of logical constraints), and configuration parameters of the projection algorithm (such as sectioning position, annotation rules, etc.). In order to reduce storage overhead, the version management module adopts differential storage technology, only recording the parameter changes between the current state and the previous version (such as the column section diameter increases by 50mm compared with the previous version) and the modified content of the constraint rules (such as the addition of pipeline clearance constraints), and finally generates a version snapshot including the above data and stores it in the model database, providing a data basis for the status tracing of the design process.

[0054] In response to the user's selection of a historical version snapshot, the version management module first verifies the compatibility of the selected snapshot (such as checking whether the parameter identifier in the snapshot is consistent with the parametric template of the current engineering design model to ensure that there are no missing or renamed parameters). After verification, the module loads the parameter solution values and constraint relationship rules in the snapshot into the engineering design model: the parameter solution values directly overwrite the corresponding parameters in the current model (such as restoring the column section diameter from 650mm to 600mm in the snapshot), and the constraint relationship rules are rebound to the associated fields of the parametric template (such as restoring the proportional constraint rules of beam span and plate thickness). After loading is completed, the system automatically triggers the iterative calculation of the constraint solving engine, recalculates the parameter solution based on the constraint relationship of the historical snapshot (if the constraint relationship in the snapshot does not conflict with the current model, the snapshot parameter solution can be used directly; if there is an environmental change or model update, the engine re-verifies the constraint relationship and outputs a new parameter solution), and generates the corresponding version of the two-dimensional construction drawing through the projection algorithm.

[0055] The above process achieves reversible traceability and rapid iteration of the design process through differential storage of version snapshots and accurate loading of historical states. Version snapshots record key design states to avoid loss of design states due to parameter adjustments or constraint modifications; historical snapshot loading operations allow users to quickly restore to any design node, re-trigger solutions and drawing generation, and significantly improve the flexibility and efficiency of engineering design.

[0056] Specifically, the method for generating parametric construction drawings based on a constraint solving algorithm of the present invention further includes: Importing the generated two-dimensional construction drawings into the review module of the engineering design model, and performing compliance verification on the geometric structures and parameters in the drawings according to preset engineering specifications; When a violation is detected, a correction suggestion associated with the violation mark is generated, and a correction operation on the constraint relationship is triggered through a user interface of the engineering design model.

[0057] The audit module of the engineering design model achieves the matching of two-dimensional construction drawings with engineering specifications through compliance verification and violation correction guidance, which specifically includes two technical steps: drawing import verification and violation correction triggering.

[0058] After the generated two-dimensional construction drawings are imported into the review module, the module performs compliance verification based on the preset engineering specification database. The engineering specification database pre-integrates mandatory engineering specifications such as the "Architectural Structural Drawing Standard" and the "Pipeline Layout Design Specification", and stores specific clauses in the specifications (such as the range of the stirrup reinforcement densification area must be marked at the beam-column node, and the minimum clear distance at the intersection of pipelines is ≥200mm) and the corresponding compliance judgment rules (such as the length of the densification area must be ≥500mm, and the clear distance marking must have a clear value). During the verification process, the module traverses the geometric structure (such as the section integrity of the beam-column node, the spatial avoidance relationship of the pipeline) and parameter information (such as the value of the dimension marking, the value of the material property), and compares the drawing content with the specification clauses one by one through the pattern matching algorithm: for the geometric structure, verify whether it meets the view expression required by the specification (such as whether a complex node generates a cross-section view); for the parameter information, verify whether the marked value is within the range allowed by the specification (such as whether the plate thickness is ≥120mm), or whether necessary markings are missing (such as the pipeline clear distance is not marked with a specific value).

[0059] When a violation is detected (such as the beam-column node without the stirrup reinforcement area marked, the pipeline clearance is only marked as "meets the specification" without a specific value), the review module generates correction suggestions associated with the violation location. Correction suggestions include the violation type (such as "missing annotation" and "parameter out of bounds"), the violation location (such as the beam-column node at the drawing coordinates [X1, Y1]) and specific correction instructions (such as "supplement the annotation of the stirrup reinforcement area length ≥ 500mm" and "mark the pipeline clearance as ≥ 200mm"). Correction suggestions are presented through the user interface of the engineering design model, usually in the form of a highlighted box marking the violation area and an additional pop-up window prompt. In some scenarios, they can be linked to the original text of the specification clause (such as "According to Article 3.2.1 of the "Architectural Structural Drawing Standard", the range of the stirrup reinforcement area must be marked at the beam-column node").

[0060] The correction suggestions fed back by the user interface directly trigger the correction operation of the constraint relationship. After the user clicks the violation prompt, the system automatically jumps to the constraint setting interface and locates the constraint rule associated with the violation content (such as the missing conditional trigger rule in the logical constraint corresponding to the unmarked stirrup reinforcement encryption area). Users can adjust the constraint relationship according to the correction suggestions (such as adding the logical constraint of "when the floor height ≥4.0m, the length of the stirrup reinforcement encryption area ≥500mm"), or modify the parameter value range (such as adjusting the size constraint of the plate thickness from 120mm to 150mm to 130mm to 160mm to meet the requirements of the specification). After the constraint relationship is corrected, the system re-triggers the iterative calculation of the constraint solving engine and the generation process of the two-dimensional construction drawings until the review module is verified and passed, forming a closed-loop verification mechanism for design data and engineering specifications.

[0061] The above process ensures that the generated two-dimensional construction drawings meet the requirements of engineering specifications through automatic comparison of the specification database, precise positioning of illegal locations and targeted correction of constraint relationships. At the same time, the linkage operation of the user interface reduces the cost of manual verification and improves the compliance and reliability of design results.

[0062] Specifically, the method for generating parametric construction drawings based on a constraint solving algorithm of the present invention further includes: Receiving a parameter adjustment instruction input by a remote user through the multi-terminal collaborative interface of the engineering design model, the parameter adjustment instruction including a target parameter identifier and an updated value; Based on the dynamically updated constraint relationship of the parameter adjustment instruction, the parameter solution calculation and the regeneration of the two-dimensional construction drawings are synchronously triggered by the constraint solving engine.

[0063] The multi-terminal collaborative interface of the engineering design model realizes real-time synchronization and collaboration of cross-terminal design data by receiving remote parameter adjustment instructions, dynamically updating constraint relationships and triggering drawing regeneration. It specifically includes three technical steps: instruction reception and processing, constraint relationship updating and solving drawing output triggering.

[0064] When the multi-terminal collaboration interface receives a parameter adjustment instruction input by a remote user, it uses a standardized communication protocol (such as WebSocket or HTTP) to implement data transmission. The remote user submits a parameter adjustment instruction through a collaborative design terminal (such as a mobile device, a remote workstation). The instruction is encapsulated in a structured data format (such as JSON), including a target parameter identifier (such as unique identifiers like "P_beam span", "P_column section diameter", etc.) and an updated value (such as "L = 6200mm", "D = 700mm"). After receiving the instruction, the interface first performs identity authentication (such as verifying user permissions or digital signatures) and instruction integrity verification (such as checking whether the parameter identifier exists and whether the format of the updated value meets numerical requirements) to ensure that the instruction source is legal and the content is valid. The verified instruction is parsed into a key-value pair of the target parameter identifier and the updated value, which serves as the input data for updating the constraint relationship.

[0065] When dynamically updating the constraint relationship based on the parameter adjustment instruction, the system locates the constraint rules associated with the parameter in the engineering design model according to the target parameter identifier. For example, if the instruction is "P_beam span = 6200mm", the system first searches for the dimension constraints (such as the original constraint "beam span ≤ 6000mm"), geometric constraints (such as "beam span aligns with column spacing"), and logical constraints (such as "beam span = 1.2 × slab thickness") associated with the beam span parameter. Then, it adjusts the relevant constraint rules according to the updated value: modifies the dimension constraint to "beam span ≤ 6200mm", verifies whether the alignment relationship of the geometric constraint needs to be adjusted synchronously (such as whether the column spacing allows the beam span to extend to 6200mm), and checks whether the logical constraint needs to be updated (such as whether the slab thickness parameter needs to be adjusted to maintain the proportional relationship of "beam span = 1.2 × slab thickness"). After the format verification (such as ensuring the syntactic correctness of the constraint rules) of the updated constraint relationship, it replaces the original constraint rules in the engineering design model to form a new set of parameter constraint relationships.

[0066] After the constraint relationship update is completed, the system synchronously triggers the parameter solution calculation of the constraint solving engine and the regeneration of the two-dimensional construction drawings. The constraint solving engine loads the updated set of parameter constraint relationships and re-executes the iterative calculation (such as checking whether the new constraints conflict with other rules, and if so, performing weight assignment and relaxation calculation based on the preset priority) until the parameter solution that meets all constraint conditions is output. After the parameter solution is generated, the projection algorithm adjusts the geometric structure of the parametric template based on the updated parameter values (such as extending the length of the beam member to 6200mm) and regenerates the two-dimensional construction drawings (such as updating the dimension annotation of the beam span and adjusting the sectional views of relevant nodes). The generated drawings are synchronized to all associated terminals through the multi-terminal collaboration interface, enabling remote users to view the latest design results in real time.

[0067] Through the standardized instruction transmission and verification, accurate constraint relationship positioning and updating, and synchronous drawing generation trigger mechanism for solving, the above process realizes the real-time linkage between parameter adjustment and drawing update in the multi-terminal collaborative design scenario, avoids design conflicts caused by information asynchronization, and improves the efficiency and consistency of multi-disciplinary and multi-location collaborative design.

[0068] Specifically, the parametric construction drawing generation method based on the constraint solving algorithm described in the present invention further includes: Based on the multi-disciplinary collaborative data interface, associatively map the parametric template with the external BIM design model, and establish the synchronization rule between the variable parameters in the parametric template and the parameters of the external BIM design model; When it is detected that the parameters of the external BIM design model change, automatically update the constraint relationship of the parametric template based on the synchronization rule, and trigger constraint solving and drawing generation.

[0069] The engineering design model realizes parameter linkage with the external BIM design model through the multi-disciplinary collaborative data interface, which specifically includes two technical steps: establishing parameter associative mapping and updating in response to parameter changes, aiming to improve the efficiency and consistency of multi-disciplinary collaborative design through cross-system data synchronization.

[0070] The establishment of the associative mapping of the multi-disciplinary collaborative data interface is based on the parameter correspondence between the parametric template and the external BIM model. The interface uses a standardized data format (such as the IFC Industry Foundation Class standard) to communicate with the external BIM model. First, extract the key parameters in the external BIM model (such as column positioning coordinates, beam section dimensions, pipeline material properties, etc.), and assign a unique identifier to each parameter (such as "BIM_Column X Coordinate", "BIM_Beam Height"). At the same time, the variable parameters defined in the parametric template (such as "Template_Column X Coordinate", "Template_Beam Height") have been pre-bound to the geometric attribute fields of the template (such as the position coordinates of column components, the section height of beam components). The system establishes the correspondence between the external BIM parameters and the parametric template parameters (such as mapping "BIM_Column X Coordinate" to "Template_Column X Coordinate") through the parameter mapping configuration interface, and defines the synchronization rule (such as direct numerical synchronization, linear conversion rule "Template_Beam Height = BIM_Beam Height + 50mm" or conditional mapping rule "When BIM_Pipeline Material is steel pipe, Template_Pipeline Clearance = 200mm"). The mapping relationship and synchronization rule are stored in the engineering design model in the form of a configuration file as the basis for cross-system parameter linkage.

[0071] When parameter changes in the external BIM design model are detected, the system automatically updates the constraint relationships of the parametric template based on the synchronization rules. The parameter changes in the external BIM model are captured through an event listening mechanism (such as the BIM software triggering a "parameter modification" event and sending a notification). After the interface receives the event, it parses the changed parameter identifier (such as "BIM_column X coordinate") and the new value (such as "X = 5200mm"), and queries the mapping configuration file to obtain the corresponding parametric template parameters (such as "template_column X coordinate") and the synchronization rule (such as direct synchronization). The system updates the corresponding parameters in the parametric template according to the synchronization rule (such as updating "template_column X coordinate" from 5000mm to 5200mm), and checks the constraint relationships associated with this parameter (such as the column centerline alignment rule in geometric constraints and the ratio relationship between column spacing and beam span in dimension constraints). If the parameter update causes the constraint relationship to be incompatible (such as after the column X coordinate changes, the original dimension constraint of "column spacing = 6000mm" needs to be adjusted), the system automatically adjusts the relevant constraint rules (such as modifying the column spacing constraint to "column spacing = current column X coordinate - adjacent column X coordinate"), forming a new set of parameter constraint relationships.

[0072] After the parameter constraint relationship update is completed, the system triggers the iterative calculation of the constraint solving engine and the generation of two-dimensional construction drawings. The constraint solving engine loads the updated set of constraint relationships, recalculates the parameter solutions (such as verifying whether the associated parameters such as beam span and slab thickness satisfy the constraint conditions after the column X coordinate changes, and if there are conflicts, performing weight assignment and relaxation calculations based on the preset priorities) until a conflict-free parameter solution is output. The projection algorithm adjusts the geometric structure of the parametric template based on the updated parameter values (such as adjusting the position of column members and extending the length of beam members to match the new column spacing), and regenerates the two-dimensional construction drawings (such as updating the column positioning markings and adjusting the beam span dimension markings). The generated drawings are synchronized to each professional design terminal through the user interface of the engineering design model and the multi-terminal collaboration interface, realizing real-time linkage between BIM model changes and construction drawing updates.

[0073] The above process realizes the deep collaboration between the parametric template and the external BIM model through parameter mapping of the standardized data interface, event-driven change detection, and automatic adjustment of constraint relationships. The parameter synchronization rule ensures the consistency of cross-system data, and the dynamic update of constraint relationships avoids manual repeated adjustments, significantly improving the efficiency and accuracy of construction drawing generation in multi-disciplinary collaborative design.

[0074] The present invention provides a method for generating parametric construction drawings based on a constraint solving algorithm, and the specific implementation process is as follows: The method realizes the automatic generation and dynamic adjustment of construction drawings through the collaborative work of the parametric template and the constraint solving engine. The following details the specific implementation steps of the technical solution: In the creation stage of the engineering design model, a digital model framework including parametric templates needs to be constructed. The parametric templates form an initial template library by analyzing the general structural features of historical engineering drawings and extracting the basic geometric topological relationships and variable parameter ranges. After the user selects a basic template from the template library through the interactive interface, custom parameters can be added based on the current engineering requirements, such as the size threshold of components, material properties, or connection rules. This template is embedded in the engineering design model and serves as the core carrier for subsequent constraint setting and drawing generation.

[0075] The process of setting constraint conditions is carried out around the association rules between parameters. The user inputs geometric constraints, dimension constraints, and logical constraints through the graphical interface: Geometric constraints are used to define the relative positions and topological relationships between components, such as the alignment method of beam-column joints or the spatial avoidance rules of pipelines; Dimension constraints generate length, angle, or ratio associations based on the numerical ranges set by the user, such as the ratio limit between wall thickness and floor height; Logical constraints describe the dynamic relationships between parameters through formulaic expressions, such as triggering the size adjustment of adjacent components when the length of a certain component exceeds the threshold. All constraint conditions are integrated into a set of parameter constraint relationships, forming the input data for subsequent parsing and solving.

[0076] The formula parser is responsible for converting the set of constraint relationships into a machine-recognizable rule form. In the parsing process, the geometric association rules, dimension association rules, and logical expressions are first unified into an intermediate expression format, such as structured data based on JSON or XML. Subsequently, a hierarchical parsing of the intermediate expression is performed through a syntax tree construction algorithm to generate a tree structure reflecting the dependency relationships between parameters. The semantic verification module verifies the syntax tree to check whether it is compatible with the parameter types and value ranges defined in the parametric template, avoiding rule conflicts or out-of-bounds errors. The syntax tree that passes the verification is converted into a set of parameter association rules executable by the constraint solving engine, realizing the computability of the rules.

[0077] The constraint solving engine adopts an iterative calculation and conflict resolution strategy to process the set of parameter association rules. When the engine is initialized, a preset conflict resolution strategy is loaded, such as a weight assignment rule or a relaxation algorithm based on parameter priorities. When a conflict is detected in the rule set, the engine performs iterative backtracking based on the priorities of the conflicting parameters and performs relaxation calculations on the conflicting parameters by adjusting the weight values, such as reducing the weight of non-critical components to give priority to meeting the core dimension requirements. The calculation results are fed back to the parametric template of the engineering design model in real time, driving the dynamic update of the template parameters until a conflict-free parameter solution that meets all constraint conditions is output. If the conflict cannot be automatically resolved, the engine generates an adjustable parameter range and prompts through the user interface, triggering manual intervention and constraint condition correction.

[0078] After the parametric solution is generated, the updated parametric template is mapped to a 2D construction drawing through a projection algorithm. The projection algorithm is based on the principle of orthogonal projection and combines the geometric structures and dimension rules defined in the parametric template to automatically generate a plan view that complies with engineering drawing specifications. For example, for complex 3D node connections, the algorithm automatically generates sectional views and detail drawings according to the topological relationships to completely represent hidden components and spatial relationships in the 2D drawing. The generated drawing is saved as a version snapshot including the current parametric solution and constraint relationships by the version management module, supporting users to trace back to historical states and re-trigger the solution process.

[0079] The compliance check of the drawing is implemented through an audit module. The audit module loads a preset engineering specification database and automatically compares the geometric structures, annotation information, and parameter ranges in the drawing. When a violation mark is detected, the module generates a correction suggestion associated with the violation location, such as missing component dimensions or material parameters exceeding the threshold. After the correction suggestion is fed back through the user interface, it is directly associated with the constraint condition setting module to trigger the adjustment of the corresponding constraint rules and the regeneration of the drawing.

[0080] Multi-terminal collaboration and external model linkage are achieved through a dedicated interface. Remote users submit parameter adjustment instructions through the multi-terminal collaboration interface, and the instructions include the unique identifier and updated value of the target parameter. After receiving the instructions, the engineering design model dynamically updates the relevant constraint conditions and simultaneously triggers the iterative calculation of the constraint solution engine and the real-time refresh of the drawing. For multi-disciplinary collaboration scenarios, the parametric template establishes a parameter mapping relationship with the external BIM design model through a data interface. When the parameters in the BIM model change, the mapping rules are automatically synchronized to the constraint relationships of the parametric template to drive constraint solution and drawing update, achieving the consistency of cross-system data.

[0081] The above steps achieve full-process linkage through the data center function of the engineering design model. The parametric template, as the core carrier, runs through the entire life cycle of constraint setting, rule parsing, conflict resolution, and drawing generation. The collaborative work of the constraint solution engine and the formula parser solves the lag problem of parameter adjustment and drawing update in traditional methods. The introduction of the version management, compliance check, and multi-terminal collaboration modules further improves the robustness and engineering applicability of the system, realizing the intelligence and automation of the construction drawing generation process.

[0082] The parametric construction drawing generation method of the present invention is realized through the following technical solutions: In the creation stage of the engineering design model, a digital model framework embedded with parametric templates needs to be constructed. The parametric templates are based on DXF or DWG files of historical engineering drawings or system-defined sketch templates. Through feature extraction algorithms, common structural features are identified, such as the axis intersection coordinates of beam-column joints and the topological relationships of pipeline layouts, to generate an initial template library. After the user selects a template through the interactive interface, custom parameters associated with engineering requirements can be added. For example, the column section diameter can be defined as an interval parameter (500mm ≤ D ≤ 800mm) and bound to the geometric attribute fields of the template. The templates are stored in a structured data format, including parameter names, types, value ranges, and association rule fields, providing a data basis for subsequent constraint settings.

[0083] During the constraint condition setting process, the user defines geometric, dimensional, and logical association rules through the graphical interface. Geometric constraints are generated based on the topological structure of the template. For example, the centerline alignment tolerance of adjacent column members is set to ±5mm, and the minimum clear distance between the pipeline and the beam bottom is constrained to 200mm. Dimensional constraints are set through numeric input boxes or sliders. For example, the plate thickness parameter is limited to [120mm, 150mm], and a proportional relationship is established with the adjacent beam span (L_beam = 1.2 × L_plate). Logical constraints are defined using formulaic expressions. For example, when the floor height H ≥ 4m, an automatic adjustment rule for the column section diameter D is triggered (D = H / 8 + 300mm). After all constraint conditions pass the format check, they are integrated into a set of parameter constraint relationships, including constraint types, acting parameters, and expression data.

[0084] When the formula parser analyzes the set of constraint relationships, it first converts geometric rules into distance equations (such as |X1 - X2| ≤ 5mm), dimensional proportional relationships into linear equations (such as k1 × L1 + k2 × L2 = 0), and logical conditional statements into piecewise functions. The parsed intermediate expressions are used to generate an abstract syntax tree (AST) through a syntax tree construction algorithm. The tree nodes include operators, parameter identifiers, and constant values. The semantic verification module traverses the syntax tree nodes to verify the existence of parameters, type matching (e.g., length parameters cannot be added to angle parameters), and compliance of value ranges (e.g., whether the plate thickness is within the range of [120mm, 150mm]). The syntax tree that passes the verification is serialized into an instruction set recognizable by the constraint solver. For example, the linear equation is converted into matrix form Ax = b, where A is the coefficient matrix and b is the constraint constant.

[0085] The constraint solving engine uses an iterative algorithm to process the parameter association rule set, and loads the conflict resolution strategy during initialization. For example, the priority of defining structural safety parameters (such as column bearing capacity) is higher than that of economic parameters (such as concrete dosage). When a constraint conflict is detected, the engine relaxes the conflicting parameters according to the priority: retaining strict constraints for high-priority parameters (such as D≥600mm), and relaxing constraints for low-priority parameters (allowing the plate thickness to float within the range of [110mm, 150mm]). After each iteration, the updated parameter values are fed back to the parametric template in real time to drive the geometric reconstruction of the 3D model. If the iteration fails to converge after more than 10 times, the engine generates an adjustable range for the conflicting parameters (such as recommending that the beam span be adjusted to 4800-5200mm), and highlights the constraints that need to be manually corrected through the user interface.

[0086] When the projection algorithm generates two-dimensional drawings, it uses a combination of orthogonal projection and dynamic sectioning. For the three-dimensional model in the parametric template, the main view is generated along the axis direction, and the sectioning position is automatically selected according to the component density. For example, when generating a section view at the beam-column node, the algorithm uses the 50% position of the beam height as the section plane, retaining the information of stirrup spacing (such as @100mm) and the number of longitudinal reinforcements (such as 8Φ20). The annotation module automatically generates dimension annotations based on the values in the parameter solution. For example, the column section diameter D=650mm is converted into the "D650" annotation text and associated with the template parameter identifier. The generated construction drawings are output in DWG format, and the current parameter solution, constraint relationship and projection parameters are recorded through the version management module to form a version snapshot.

[0087] The version management module uses differential storage technology to record only the parameter changes between versions. When the user selects a historical snapshot, the module parses the snapshot data and reloads it into the engineering design model, triggering the iterative calculation of the constraint solving engine. For example, when rolling back to version V2, the column diameter parameter is restored from 650mm to 600mm, and the engine recalculates the associated beam span and plate thickness parameters, generates an updated 2D drawing, and accurately restores the historical state.

[0088] The audit module integrates the engineering specification database, including mandatory clauses such as the "Architectural Structural Drawing Standard". During verification, the module traverses the geometric elements and annotation information in the drawings, and checks whether the beam-column nodes are marked with the stirrup reinforcement area range (such as ≥500mm) and whether the minimum clearance mark is retained at the intersection of pipelines (such as ≥200mm). If a violation is detected (such as the plate thickness is marked as 110mm but the constraint condition is set to ≥120mm), the module generates correction suggestions and locates the corresponding constraint relationship entry. The user can directly jump to the constraint setting interface to adjust the parameter range or association rules.

[0089] The multi-terminal collaboration interface realizes data synchronization based on the WebSocket protocol. When a remote user submits a parameter adjustment instruction, the instruction message includes a parameter ID (such as "P_beam span"), a target value (such as L = 8000mm), and a timestamp. After receiving the instruction, the engineering design model updates the corresponding constraint conditions and broadcasts them to all terminals, triggering constraint solving and drawing refreshing. For BIM model linkage, parameter change events of external models are parsed through the IFC format. For example, when the column positioning coordinates in BIM are modified by Δx = 200mm, the mapping rule converts Δx into the axis offset of the parametric template, triggering the recalculation of the dimensions of associated components and updating the positioning annotations in the 2D drawing to achieve consistent cross-system data linkage.

[0090] The above embodiments transform the abstract steps of the claims into operable technical details through a hierarchical technical solution. The construction and parsing process of the parametric template supports the template creation step; the iterative strategy and conflict handling mechanism of the constraint solving engine improve the parameter solution generation process; the collaboration between the projection algorithm and the review module realizes the closed-loop of drawing generation and compliance verification. The data flow between modules (such as parameter constraint set → syntax tree → solution instruction set) provides a full implementation basis for the technical features of the claims.

[0091] The present invention provides a method for generating parametric construction drawings based on a constraint solving algorithm. Its core process realizes automatic drawing through the collaboration of a parametric template and a constraint solving engine. First, a parametric template is embedded in the engineering design model, which defines the basic structure of the construction drawing (such as the layout of beam and column axes) and variable parameters associated with engineering requirements (such as component dimensions, material properties). Users input geometric, dimensional, and logical constraint conditions based on actual needs, such as defining the alignment tolerance between adjacent components or the proportional relationship between parameters, to generate a set of parameter constraint relationships. Subsequently, the formula parser converts the constraint rules into intermediate expressions, and through syntax tree construction and semantic verification, generates a set of parameter association rules that can be recognized by the constraint solving engine. The constraint solving engine uses an iterative algorithm to process the rule set and outputs parameter solutions that satisfy all constraint conditions in combination with a conflict resolution strategy (such as priority weight assignment). Finally, the updated parametric template is mapped into a 2D construction drawing that conforms to engineering drawing specifications through a projection algorithm, realizing dynamic drawing driven by parameters.

[0092] Further refine the types and action mechanisms of constraint relationships. Geometric constraints are used to define the relative positions (such as the alignment tolerance of column centerlines ±5mm) and topological relationships (such as pipeline avoidance rules) of graphical elements in engineering design models, and generate geometric association rules based on the basic structure of parametric templates. Dimension constraints define the length, angle, or proportional relationships of components based on the numerical ranges input by users (such as wall thickness [120mm, 150mm]), and are converted into linear equations or proportional rules through a formula parser. Logical constraints describe the dynamic associations between parameters through formulaic expressions (such as conditional trigger rules), for example, automatically adjusting the column section size when the floor height exceeds a threshold. The logical expressions are parsed and then input into the constraint solving engine after parsing. The three types of constraints work together to cover the spatial layout, dimension compliance, and dynamic adjustment requirements in engineering design.

[0093] The parsing process of the formula parser is divided into three stages. First, geometric association rules, dimension association rules, and logical expressions are uniformly converted into an intermediate expression format (such as JSON or XML) to eliminate the format differences of different constraint types. Subsequently, a hierarchical parsing of the intermediate expressions is performed through a syntax tree construction algorithm to generate a tree-like structure reflecting the parameter dependency relationships. The semantic verification module traverses the syntax tree nodes to verify the existence of parameters, type matching (such as length parameters cannot be added to angle parameters), and value range compliance (such as whether the slab thickness is within the set interval). The syntax tree that passes the verification is serialized into an instruction set executable by the constraint solving engine (such as the matrix equation Ax = b) to achieve the computability of the rules and model compatibility.

[0094] The creation of parametric templates is based on data mining and reuse of historical engineering drawings. Through feature extraction algorithms (such as axis intersection recognition, topological relationship analysis), general structural features are extracted from historical drawings to generate an initial template library associated with the engineering design model. After the user selects a template through the interactive interface, custom parameters can be added based on the current engineering requirements. For example, a cantilever length parameter can be added or the material strength threshold can be adjusted in the selected beam-column template. The templates loaded into the model automatically inherit the structural features of the historical data and at the same time support flexible parameter expansion, taking into account both design efficiency and personalized needs.

[0095] When the constraint solving engine detects conflicts in the set of parameter association rules, iterative backtracking is performed based on the preset conflict parameter priorities in the model (such as structural safety parameters taking precedence over economic parameters). The engine assigns weights to the conflict parameters according to the priorities. For example, strict constraints are retained for the dimensions of key components, allowing secondary parameters to float within a certain range. The calculation results are fed back to the parametric template in real time to drive the dynamic update of the template parameters. If conflicts still exist after iteration, the engine generates an adjustable range for the conflict parameters (such as suggesting that the beam span be adjusted to 4800 - 5200mm), and highlights the constraint items that need to be corrected through the user interface to guide the user to adjust the constraint conditions or parameter thresholds.

[0096] The specific implementation of iterative backtracking includes weight assignment rules and relaxation calculations. The conflict resolution strategy defines the weight assignment rules according to the priorities of conflict parameters. For example, the weight coefficient of the column bearing capacity parameter is higher than that of the concrete usage parameter. Based on the weight rules, the engine performs relaxation calculations on the conflict parameters, gradually relaxing the constraints of low-priority parameters (such as allowing the slab thickness to float within the range of [110mm, 150mm]) until a conflict-free parameter solution is output. The calculation results are synchronized to the parametric template in real time to achieve dynamic update and consistency of model data.

[0097] After generating the 2D construction drawings, the version management module automatically records the current parameter solution and constraint relationships to form a version snapshot. The snapshot uses differential storage technology and only saves the parameter change amounts to reduce storage overhead. When the user selects a historical version, the module parses the snapshot data and reloads it into the engineering design model, triggering the iterative calculation of the constraint solving engine. For example, when rolling back to version V2, the column diameter parameter is restored from 650mm to 600mm, and the engine recalculates the associated beam span and slab thickness parameters to generate updated 2D drawings, realizing reversible traceability and rapid iteration of the design state.

[0098] The review module integrates an engineering specification database (such as the Standard for Architectural Structure Drawing) to perform compliance verification on the generated 2D drawings. The verification process traverses the geometric structures (such as the connection method of beam-column joints) and annotation information (such as dimensional tolerances) in the drawings to detect whether they meet the preset specifications. If violations are found (such as the slab thickness annotation value being lower than the constraint conditions), the module generates correction suggestions associated with the violation locations (such as prompting to adjust the slab thickness to ≥120mm) and locates the corresponding constraint relationship entries through the user interface, directly triggering the correction of the constraint conditions and the regeneration of the drawings.

[0099] The multi-terminal collaboration interface supports remote users to adjust design parameters in real time. The user submits parameter adjustment instructions (such as modifying the beam span L = 8000mm) through the interface, and the instruction message includes the target parameter identifier and the updated value. After receiving the instruction, the engineering design model dynamically updates the constraint conditions and synchronously triggers the iterative calculation of the constraint solving engine. The calculation results drive the adjustment of the parametric template in real time, and updated 2D drawings are generated through the projection algorithm to achieve data synchronization and rapid response under multi-terminal collaborative design.

[0100] Through a multi - professional collaborative data interface, a parametric template establishes a parameter mapping relationship with an external BIM design model. For example, the column positioning coordinates in the template are bound to the axis coordinates of the BIM model, and synchronization rules are defined. When the parameters of the BIM model change (such as the column position offset Δx = 200 mm), the mapping rules automatically update the constraint relationships of the parametric template, triggering the constraint solving engine to recalculate and generate updated 2D drawings. This mechanism realizes cross - system data linkage, avoids manual repeated adjustment, and improves the efficiency of multi - professional collaboration.

[0101] An embodiment of the present invention in the civil engineering scenario: In the design of high - rise building beam - column structures, the method of the present invention is applied to generate construction drawings. Engineering designers select a standard - layer parametric template from the historical project library. The template includes axis grids, beam - column joint connection rules, and initial parameters (such as column section diameter D = 600 mm). According to the current project requirements, the floor height H = 3.6 m is added as a variable parameter, and constraint conditions are set: geometric constraints define the alignment tolerance of adjacent column centerlines as ±5 mm; dimensional constraints set the proportional relationship between column diameter D and floor height H as D = H / 6 + 250 mm; logical constraints add a conditional trigger rule that when the floor height H≥4.0 m, the associated rule for automatically activating the column stirrup encryption zone length ≥500 mm is activated. The formula parser converts the constraints into intermediate expressions, and after verification by the syntax tree, a set of parameter association rules is generated. When the constraint solving engine detects that the floor height H = 4.2 m, it calculates the column diameter D = 4.2 / 6 + 250 = 700 mm, triggering the stirrup encryption rule, but there is a conflict with the original template beam span L = 6000 mm. The engine performs a relaxation calculation on the beam span based on the structural safety priority and outputs L = 6200 mm as a feasible solution. The projection algorithm generates 2D drawings according to the updated parameters, automatically annotates the column D700, beam L6200, and the encryption zone range, and generates detailed sectional drawings of beam - column joints. The review module detects the missing stirrup spacing annotation in the sectional drawing, feedbacks it to the constraint condition module, and adds the stirrup @100 mm annotation rule. After re - triggering the solution, a complete drawing is generated. The multi - terminal collaborative interface synchronously updates the parameters to the BIM model. When the external model adjusts the column positioning coordinate Δx = 200 mm, the mapping rules drive the update of the template parameters and regenerate the positioning annotation, realizing cross - system data consistency.

[0102] Through the collaborative mechanism of the parametric template and the constraint solving engine, the present invention systematically solves the technical problems in the transformation from 3D models to construction drawings. First, based on engineering drawing specifications, the parametric template defines the structural features of construction drawings and the association rules of variable parameters. The spatial topological relationships between components are solidified through geometric constraints (such as the axis alignment tolerance of beam-column joints), the numerical ratios between parameters are set through dimensional constraints (such as the dynamic association between wall thickness and floor height), and the dynamic adjustment rules triggered by conditions are described through logical constraints (such as automatically strengthening the column section when the storey height exceeds the limit). The three types of constraints are converted into a set of computable association rules through a formula parser, and the constraint solving engine iteratively outputs conflict-free parameter solutions based on the conflict resolution strategy, realizing the geometric and logical integrity of the drawings during parameter adjustment and avoiding the loss of details during the projection process.

[0103] Regarding the compliance issue of drawing specifications, the system has an in-built audit module that is linked to the engineering specification database. When the projection algorithm generates 2D drawings, in combination with the structural definitions and drawing rules in the parametric template, it automatically generates standard-compliant view expressions (such as multi-directional sectional views of complex nodes). The audit module traverses the geometric structure, annotation information, and parameter ranges of the drawings, and compares them in real time with the preset specification items (such as the integrity of stirrup encryption zone annotations, pipeline net distance thresholds). When violations are detected, it generates precisely positioned correction suggestions (such as the missing beam span dimension in the annotation), and is reversely associated with the constraint condition setting module to trigger the iterative update of the constraint rules, realizing the closed-loop linkage between design data and drawing specifications.

[0104] Regarding the bottleneck in drawing generation efficiency, the system optimizes the process through a multi-terminal collaboration interface and an external model mapping mechanism. After a remote user submits a parameter adjustment instruction, the constraint solving engine synchronously calculates based on the dynamically updated constraint relationships, driving the real-time reconstruction of the parametric template and the drawing refresh. The parameter mapping rules with external BIM models (such as axis coordinate synchronization) enable cross-system data linkage, and automatically trigger constraint solving and drawing update when changes in the external model are detected. The version management module records snapshots of parameter solutions and constraint relationships, supporting one-key backtracking and re-solving of historical states, eliminating the redundant operations of manual repetitive adaptation of model iterations in traditional methods, and significantly improving the robustness of drawing generation and the multi-disciplinary collaboration efficiency.

Claims

1. A parametric construction drawing generation method based on a constraint solving algorithm, characterized in that Including: Create an engineering design model, in which a parametric template is embedded, and the parametric template defines the basic structure of the construction drawings and variable parameters associated with engineering requirements; Based on the constraint conditions input by the user, set geometric associations, dimension associations, and logical associations for the variable parameters in the parametric template to generate a set of parameter constraint relationships; Parse the association rules in the set of parameter constraint relationships through a formula parser to generate a set of parameter association rules recognizable by the constraint solving engine; Input the set of parameter association rules into the constraint solving engine for iterative calculation, and the constraint solving engine outputs parameter solutions that meet all constraint conditions based on a preset conflict resolution strategy; Update the variable parameters in the parametric template according to the values in the parameter solutions, and map the updated parametric template to two-dimensional construction drawings through a projection algorithm.

2. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 1, characterized in that The set of parameter constraint relationships includes: Geometric constraints, used to define the relative positions and topological relationships of graphic elements in the engineering design model, and generate geometric association rules according to the basic structure of the parametric template; Dimension constraints, used to define the length, angle, or proportional relationship of graphic elements according to the numerical range input by the user, and convert them into dimension association rules through the formula parser; Logical constraints, used to generate logical expressions based on the formulaic associations or conditional trigger rules between parameters, and the logical expressions are input into the constraint solving engine after being parsed by the formula parser.

3. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 2, characterized in that Parse the association rules in the set of parameter constraint relationships through a formula parser to generate a set of parameter association rules recognizable by the constraint solving engine, including: Convert geometric association rules, dimension association rules, and logical expressions into intermediate expressions in a unified format; Construct a syntax tree for the intermediate expressions, and verify the compatibility of the syntax tree with the parametric template of the engineering design model through a semantic verification module; Generate a set of parameter association rules executable by the constraint solving engine according to the syntax tree that passes the verification.

4. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 3, wherein The creation of the parametric template includes: Extract general structural features from historical engineering drawings to generate an initial template library associated with the engineering design model; In response to the user's selection operation on the template in the initial template library, load the selected template into the engineering design model, and add custom parameters associated with the template according to the engineering requirements input by the user.

5. The parametric construction drawing generation method based on the constraint solving algorithm according to claim 4, wherein Also including: When the constraint solving engine detects conflicts in the generated set of parameter association rules, perform iterative backtracking based on the preset conflict parameter priorities in the engineering design model to determine the weight distribution of the conflict parameters; Generate an adjustable range for the conflict parameters according to the weight distribution, and feedback the adjustable range through the user interface of the engineering design model to trigger the user to correct the constraint relationships.

6. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 5, wherein, The iterative backtracking includes: Determine the weight distribution rules in the conflict resolution strategy according to the conflict parameter priorities; Perform relaxation calculations on the conflict parameters based on the weight distribution rules, and feedback the calculation results to the parametric template in the engineering design model until the constraint solving engine outputs parameter solutions without conflicts.

7. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 6, wherein Also including: The version management module based on the engineering design model generates a version snapshot including the current parameter solution and constraint relationships. In response to the user's selection operation on the historical version snapshot, load the parameter solution and constraint relationships in the version snapshot into the engineering design model, and re-trigger constraint solving and drawing generation.

8. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 7, characterized in that, It also includes: The review module that imports the generated 2D construction drawings into the engineering design model, and performs compliance verification on the geometric structures and parameters in the drawings according to the preset engineering specifications. When a violation is detected, generate a correction suggestion associated with the violation mark, and trigger an operation to correct the constraint relationship through the user interface of the engineering design model.

9. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 8, wherein It also includes: Receive the parameter adjustment instruction input by the remote user through the multi-terminal collaboration interface of the engineering design model. The parameter adjustment instruction includes the target parameter identifier and the updated value. Dynamically update the constraint relationship based on the parameter adjustment instruction, and synchronously trigger parameter solution calculation and regeneration of the 2D construction drawing through the constraint solving engine.

10. The parametric construction drawing generation method based on a constraint solving algorithm according to claim 9, characterized in that It also includes: Based on the multi-disciplinary collaboration data interface, associate and map the parametric template with the external BIM design model, and establish a synchronization rule for the variable parameters in the parametric template and the parameters of the external BIM design model. When it is detected that the parameters of the external BIM design model change, automatically update the constraint relationship of the parametric template based on the synchronization rule, and trigger constraint solving and drawing generation.

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