Schematic pipeline three-dimensional model generation method based on spatial topological relation constraint

Abstract

The invention relates to a spatial topological relation constraint-based schematic pipeline three-dimensional model generation method, which comprises the following steps of: integrating data in an underground pipe network information data set into a unified coordinate system, extracting and retaining important attributes in underground pipe network information, taking roads and plots as spatial constraints, and on the basis of ensuring a pipeline topological relation, generating a three-dimensional model of an underground pipe network. Based on a noise-controllable random disturbance model and a spring-damping model, desensitization and decryption are realized while small displacement of the position of the underground pipeline is simulated, collision detection and conflict correction are continuously performed on preset spatial constraint conditions, and spatial constraint condition inspection is performed on the underground pipeline after displacement each time. And then calling a CityGML standard template to generate a schematic pipeline three-dimensional model for the current underground pipe network information based on the disturbed node coordinates of the underground pipeline and the reserved attribute information, so that the desensitization and decryption of the underground pipeline information are realized, and more topological structures and spatial distribution characteristics of the underground pipeline are reserved.

Description

Technical Field

[0001] The present invention relates to the field of underground pipeline network data processing, and particularly to a method for generating a schematic three-dimensional pipeline model based on spatial topological relationship constraints. Background Art

[0002] The underground pipeline network system is an important part of the urban pipeline network system, and the pipeline information data of the underground pipeline network system is of great significance for urban pipeline network maintenance and response to emergencies.

[0003] In the existing management process of underground pipeline network information data, insufficient sharing of pipeline information easily increases the risk of third parties damaging underground pipelines during construction. Since the current management of underground pipeline networks still remains at the manual operation stage for a long time, it is difficult to respond to emergencies, reducing the efficiency of underground pipeline network construction and maintenance. At the same time, the closed management of pipeline information also easily causes the underground pipeline network management system to become a "zombie system", and its data cannot be effectively fed back or updated, thus forming a "data island". Therefore, realizing the sharing of underground pipeline network information is an important measure to break the "data island" and improve the maintenance and management efficiency of underground pipeline networks.

[0004] Since underground pipeline information belongs to the category of confidentiality, it needs to be strictly managed through measures such as pipeline decryption and desensitization methods. The existing underground pipeline information decryption and desensitization methods are mainly the following forms: The first is the grid-based desensitization processing method, that is, converting pipeline data into map grids for desensitization to generate a desensitized layer; the second is the numerical and attribute desensitization method, that is, offsetting or blurring sensitive numerical values such as elevation and pipe diameter to reduce data accuracy, and at the same time deleting or replacing some confidential attributes to only retain basic geographical information; the third is a method combining neural network transformation and Chebyshev polynomial model, and through control point perturbation and model coefficient iteration, irreversible desensitization of spatial data is achieved.

[0005] However, the existing underground pipeline information processing methods adopted to meet underground information sharing have deficiencies: They do not consider range control and the topological relationship between pipelines, which easily leads to the pipeline position deviating from the reasonable range, or causes errors in the topological relationship between pipelines, and then results in abnormal situations such as pipeline collisions or intersections.

[0006] Therefore, how to meet the sharing of underground pipeline information on the premise of ensuring the security and confidentiality of pipeline information and retaining the topological relationship between pipelines is a technical problem that urgently needs to be solved in the current field of underground pipeline information management. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints for the above-mentioned existing technologies. This method for generating a schematic pipeline three-dimensional model can ensure that the requirements for sharing underground pipeline information are met while ensuring the security and confidentiality of pipeline information and retaining the topological relationships between pipelines.

[0008] The technical solution adopted by the present invention to solve the above technical problems is as follows: A method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints, characterized by including the following steps: Step 1, perform data integration and preprocessing on the underground pipe network information data set, integrate the data in the underground pipe network information data set into a unified coordinate system, and extract and retain the important attributes in the underground pipe network information; Step 2, preset spatial constraint conditions for restricting the spatial range of underground pipe network pipeline distribution based on the road surface and plot range involved in the underground pipe network; Step 3, implement the position offset of underground pipelines based on a noise-controllable random perturbation model, and use a spring-damping model to constrain the spacing between the perturbed underground pipelines, so as to maintain the relative topological relationship while simulating the position offset of underground pipelines; Step 4, perform collision detection and conflict correction on the preset spatial constraint conditions to ensure that the offset underground pipelines do not exceed the restricted spatial range of underground pipe network pipeline distribution; Step 5, check the spatial constraint conditions for the underground pipelines after each offset to ensure that the position offset of the underground pipelines meets the spatial constraint conditions; Step 6, based on the node coordinates after perturbation of the underground pipelines and the retained important attribute information, call the CityGML standard template to generate a schematic pipeline three-dimensional model for the current underground pipe network information.

[0009] Improved, in the method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints, the underground pipe network information data set includes underground pipeline information data, road information data, and plot information data, the important attributes include the basic attributes of the underground pipe network and the topological connection relationship, the basic attributes of the underground pipe network include the pipe diameter and material of the underground pipelines, and the topological connection relationship includes the topological connection relationships between valves, inspection wells, and pipeline connection points.

[0010] Further, in the method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints, the process of performing data integration and preprocessing on the underground pipe network information data set includes: Step a1, set the initial underground pipelines as a set of continuous line segments; Step a2, perform parameterization processing on each continuous line segment in the set of continuous line segments to obtain the parameterized continuous line segments; Step a3, set the direction vectors of the continuous line segments after parametric processing.

[0011] Further improvement: In the method for generating a schematic three-dimensional pipeline model based on spatial topological relationship constraints, by using a gradient descent algorithm to optimize the objective function, it is ensured that the connected pipelines in the underground pipe network satisfy the node collinearity condition.

[0012] Furthermore, in the method for generating a schematic three-dimensional pipeline model based on spatial topological relationship constraints, the spatial constraint conditions include the maximum curvature change, the maximum offset, the maximum disturbance offset, the minimum disturbance offset, and the minimum safety distance between pipe segments; and the disturbance offset of the underground pipeline is between the maximum disturbance offset and the minimum disturbance offset.

[0013] Improvement: In the method for generating a schematic three-dimensional pipeline model based on spatial topological relationship constraints, in step 4, an octree or an R-tree is used to hierarchically organize the roads, plots, and pipelines involved to support fast spatial relationship query and collision area location.

[0014] Further, in the method for generating a schematic three-dimensional pipeline model based on spatial topological relationship constraints, in step 4, when a collision area is detected, the projection method is used to constrain the collision area to the road or plot boundary to complete the conflict correction operation.

[0015] Compared with the prior art, the advantages of the present invention are as follows: The method for generating a schematic three-dimensional pipeline model based on spatial topological relationship constraints of the present invention integrates the data in the underground pipe network information data set into a unified coordinate system, extracts and retains the important attributes in the underground pipe network information, and then uses the roads and plots as spatial constraints. On the basis of ensuring the pipeline topological relationship, it realizes the position offset of the underground pipeline based on a noise-controllable random perturbation model, and uses a spring-damping model to constrain the distance between the perturbed underground pipelines, so as to maintain the relative topological relationship while simulating the position offset of the underground pipeline, and continuously performs collision detection and conflict correction on the preset spatial constraint conditions to ensure that the offset underground pipeline does not exceed the limited underground pipe network pipeline distribution space range, and checks the spatial constraint conditions for the underground pipeline after each offset to ensure that the position offset of the underground pipeline conforms to the spatial constraint conditions. Then, based on the perturbed node coordinates and the retained attribute information of the underground pipeline, a CityGML standard template is called to generate a schematic three-dimensional pipeline model for the current underground pipe network information. The generated schematic three-dimensional pipeline model not only realizes the desensitization and decryption of the underground pipeline information, but also retains more topological structures and spatial distribution characteristics of the underground pipeline, and meets the sharing application of the underground pipe network information to a greater extent. Brief Description of the Drawings

[0016] Figure 1Schematic flow chart of the method for generating a three-dimensional model of a pipeline based on spatial topological relationship constraints in an embodiment of the present invention. Detailed implementation manners

[0017] The present invention will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0018] This embodiment provides a method for generating a schematic three-dimensional model of a pipeline based on spatial topological relationship constraints to meet the requirements of sharing underground pipeline information on the premise of ensuring the security and confidentiality of pipeline information and retaining the topological relationship between pipelines. Specifically, referring to Figure 1 As shown, the method for generating a schematic three-dimensional model of a pipeline based on spatial topological relationship constraints in this embodiment includes the following steps 1 to 6: Step 1: Perform data integration and preprocessing on the underground pipe network information data set, integrate the data in the underground pipe network information data set into a unified coordinate system, and extract and retain the important attributes in the underground pipe network information. Specifically, the underground pipe network information data set here includes underground pipeline information data, road information data, and plot information data. The important attributes include the basic attributes of the underground pipe network and the topological connection relationship. The basic attributes of the underground pipe network include the pipe diameter and material of the underground pipeline, and the topological connection relationship includes the topological connection relationships between valves, manholes, and pipeline connection points. Step 2: Preset spatial constraint conditions for restricting the spatial range of the distribution of underground pipe network pipelines based on the road surface and plot range involved in the underground pipe network. Step 3: Implement the position offset of the underground pipeline based on a random perturbation model with controllable noise, and use a spring-damping model to constrain the distance between the perturbed underground pipelines to maintain the relative topological relationship while simulating the position offset of the underground pipeline. Step 4: Perform collision detection and conflict correction on the preset spatial constraint conditions to ensure that the offset underground pipelines do not exceed the restricted spatial range of the distribution of underground pipe network pipelines. Step 5: Check the spatial constraint conditions for the underground pipelines after each offset to ensure that the position offset of the underground pipelines meets the spatial constraint conditions. Among them, in this embodiment, the spatial constraint conditions here include the maximum curvature change amount, the maximum offset amount, the maximum perturbation offset amount, the minimum perturbation offset amount, and the minimum safety distance between pipe segments. And the perturbation offset amount of the underground pipeline is between the maximum perturbation offset amount and the minimum perturbation offset amount. Step 6: Based on the perturbed node coordinates of the underground pipeline and the retained important attribute information, call the CityGML standard template to generate a schematic three-dimensional model of the pipeline for the current underground pipe network information.

[0019] Specifically, in step 1 of this embodiment, the process of performing data integration and preprocessing on the underground pipe network information data set includes the following steps a1 to a3: Step a1: Set the initial underground pipelines as a set of continuous line segments. Among them, the initial underground pipelines are marked as , ; M is the total number of continuous line segments in the set of continuous line segments, is the i-th continuous line segment in the set of continuous line segments; Step a2: Perform parameterization processing on each continuous line segment in the set of continuous line segments to obtain the parameterized continuous line segments. Among them, the parameterized continuous line segments are marked as : ; ; Among them, is the starting point of the i-th continuous line segment , is the i-th continuous line segment 's end point; Step a3: Set the direction vector of each parameterized continuous line segment. Among them, the direction vector of the i-th continuous line segment is marked as , .

[0020] In order to satisfy the condition that adjacent pipelines in the underground pipe network meet the node collinearity condition, the schematic pipeline three-dimensional model generation method of this embodiment optimizes the objective function by means of a gradient descent algorithm to ensure that the connected pipelines in the underground pipe network meet the node collinearity condition. Among them: The objective function is set as follows: ; ; Among them, is the initial position of the node , is the initial position of the node , and that is, the observed values, is the collinearity condition constraint determinant function formed by the three-dimensional space coordinates of the nodes ( , ), and λ is the weight coefficient used to balance the priority of node position change and collinearity condition; The condition for the connected pipelines to meet the node collinearity condition is: for adjacent pipelines and , there exists a node position t i such that .

[0021] Specifically in this embodiment, the construction of the noise-controllable random perturbation model in step 3 is as follows: ; Among them, is the starting point of the i-th continuous line segment , is the position after the starting point is perturbed by step 1. α is the global perturbation intensity coefficient, β is the attenuation factor that controls the attenuation speed of the perturbation with distance, and s i is the cumulative walking distance from the current point to the starting point, is a random vector subject to an anisotropic Gaussian distribution; The spring-damping model in step 3 is constructed as follows: ; ; ; Among them, is the sum of the elastic damping forces between the node and all its adjacent nodes. J represents the total number of all adjacent nodes of the node , is the elastic damping force between the node and its j-th adjacent node . φ represents the elastic coefficient. For example, this φ is 5 to 10 times the diameter of the underground pipeline; d min represents the minimum safety distance between adjacent pipelines in the underground pipeline. For example, d min is 1.5 times the diameter of the underground pipeline; γ represents the damping coefficient. For example, the value range of γ is 10% to 20%; represents the velocity of the node , represents the velocity of the adjacent node ; Δt represents the time step. For example, the value of Δt is 0.1, and m i represents the mass of the node . For example, m i takes the unit mass 1; represents the position of the node after the t-th perturbation. The initial position of the node is the position after noise-controlled random perturbation, represents the velocity of the node at the position where it is located after the t-th perturbation. The initial velocity of the node is 0; For example, in this embodiment, some code paragraphs of the perturbation model in step 3 are as follows: import numpy as np class ControllableRandomNoisePerturbation: def __init__(self, alpha=1.0, beta=1.0, anisotropic_cov=None): """ Initialize the random perturbation model with controllable noise Parameters: - alpha: Global perturbation intensity coefficient - beta: Decay factor controlling the decay rate of perturbation with distance - anisotropic_cov: Covariance matrix of anisotropic Gaussian distribution (3x3) """ self.alpha = alpha self.beta = beta # Set the default anisotropic covariance matrix if anisotropic_cov is None: self.anisotropic_cov = np.array([[1.0, 0.5, 0.2], [0.3, 1.0, 0.4],[0.5, 0.3, 1.0]]) else: self.anisotropic_cov = anisotropic_cov def perturb_segment(self, start_point, current_point, cumulative_distance): """ Apply controllable random perturbation to the end points on the pipeline segment Parameters: - start_point: Initial position of the end point - current_point: Position of the end point after the previous perturbation - cumulative_distance: Cumulative walking distance from the current point to the start point Returns: - New position after perturbation """ In addition, it should be noted that in Step 4, an octree or an R-tree is used to hierarchically organize the roads, plots, and pipelines involved to support fast spatial relationship queries and locate the collision area. Of course, in Step 4, when a collision area is detected, the projection method is used to constrain the collision area to the road or plot boundary to complete the conflict correction operation; where: The conflict correction operation method is as follows: ; Wherein, is the adjusted position of the node, is the position of the outer node of the current spatial constraint range, ε is the adjustment step length along the normal direction, is the normal vector of the conflict surface corresponding to the collision area. According to actual needs, in this embodiment, the adjustment step length ε is 50% - 80% of the conflict distance.

[0022] Although the preferred embodiments of the present invention have been described in detail above, it should be clearly understood that various changes and modifications can be made to the present invention for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints, characterized in that, It includes the following steps: Step 1: Perform data integration and preprocessing on the underground pipeline network information data set, integrate the data in the underground pipeline network information data set into a unified coordinate system, and extract and retain the important attributes in the underground pipeline network information; Step 2: Preset spatial constraint conditions for restricting the spatial range of the distribution of underground pipeline network pipelines based on the road surface and plot range involved in the underground pipeline network; Step 3: Implement the position offset of underground pipelines based on a noise-controlled random perturbation model, and use a spring-damping model to constrain the spacing between the perturbed underground pipelines, so as to maintain the relative topological relationship while simulating the position offset of underground pipelines; Step 4: Perform collision detection and conflict correction on the preset spatial constraint conditions to ensure that the offset underground pipelines do not exceed the restricted spatial range of the distribution of underground pipeline network pipelines; Step 5: Check the spatial constraint conditions for the underground pipelines after each offset to ensure that the position offset of the underground pipelines conforms to the spatial constraint conditions; Step 6: Based on the perturbed node coordinates and the retained important attribute information of the underground pipelines, call the CityGML standard template to generate a schematic 3D pipeline model for the current underground pipeline network information.

2. The method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints according to claim 1, characterized in that, The underground pipeline network information data set includes underground pipeline information data, road information data, and plot information data. The important attributes include the basic attributes and topological connection relationships of the underground pipeline network. The basic attributes of the underground pipeline network include the pipe diameter and material of the underground pipelines, and the topological connection relationships include the topological connection relationships between valves, inspection wells, and pipeline connection points.

3. The method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints according to claim 2, characterized in that, The process of performing data integration and preprocessing on the underground pipeline network information data set includes: Step a1: Set the initial underground pipelines as a set of continuous line segments; Step a2: Perform parameterization processing on each continuous line segment in the set of continuous line segments to obtain the parameterized continuous line segments; Step a3: Set the direction vectors of each parameterized continuous line segment.

4. The method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints according to claim 3, characterized in that, By using a gradient descent algorithm to optimize the objective function, ensure that the connected pipelines in the underground pipeline network meet the condition of collinear nodes.

5. The method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints according to claim 4, characterized in that, The spatial constraint conditions include the maximum curvature change, maximum offset, maximum perturbation offset, minimum perturbation offset, and minimum safety distance between pipe segments; and the perturbation offset of the underground pipelines is between the maximum perturbation offset and the minimum perturbation offset.

6. The method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints according to claim 5, characterized in that, In Step 4, use an octree or R-tree to hierarchically organize the roads, plots, and pipelines involved to support fast spatial relationship query and positioning of the collision area.

7. The method for generating a schematic pipeline three-dimensional model based on spatial topological relationship constraints according to claim 6, characterized in that, In Step 4, when the collision area is detected, use the projection method to constrain the collision area to the road or plot boundary to complete the conflict correction operation.

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