Multi-element coordinated shifting method for keeping topological relation

Abstract

The invention relates to the technical field of map making, and discloses a multi-element coordinated shifting method for keeping a topological relation, which comprises the following steps of: acquiring original data of a vector map, cleaning geometric coordinates, and generating preprocessed vector map data; performing topological relation classification and constraint strength assignment on the vector map data to generate the total constraint strength of each map element; meanwhile, by calculating the minimum Euclidean distance of boundary points between the map elements and combining the minimum safety distance between the elements of the map making specification, the conflict degree of any two map elements is generated; on the basis of the total constraint strength of each map element and the conflict degree of any two map elements, constructing a shift objective function, performing iterative solution by adopting a gradient descent method, and generating an optimal shift vector of the map elements so as to realize coordinated shift of the map elements; according to the method, global optimal shifting is achieved, conflict transfer is avoided, shifting efficiency is improved, and map precision and topological integrity are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of mapmaking technology, and more specifically to a method for coordinated shifting of multiple elements while maintaining topological relationships. Background Technology

[0002] In the process of cartographic generalization, the densification and symbolization of spatial elements as the scale decreases inevitably lead to spatial conflicts. How to coordinate the relocation to resolve conflicts and maintain the topological relationships between elements has become a key challenge in improving map readability and the integrity of geographic information.

[0003] Traditional relocation methods are mostly based on geometric rules or local optimization strategies. While they can alleviate conflicts in specific scenarios, they struggle to maintain global topological consistency and dynamic relationships among multiple elements. Furthermore, most methods directly use uncleaned vector map data for relocation calculations. Anomalies in boundary point coordinates caused by measurement errors and data entry deviations in the original data can distort subsequent element distance calculations, leading to misjudgments of conflicts or deviations in relocation direction, ultimately disrupting topological relationships. In addition, early relocation research focused on single element types, improving local relocation effects by modifying classic algorithms. For example, for road network relocation, the Snake model controls deformation by minimizing energy, but its static parameter settings are ill-suited to complex road network topologies. Therefore, the shortcomings of existing technologies in terms of original data reliability, conflict determination standardization, relocation optimization quantification, and proactive topology maintenance make it difficult to meet the dual requirements of efficient conflict resolution and strict topology preservation in large-scale, high-precision map production. Summary of the Invention

[0004] To address the aforementioned shortcomings in existing technologies, this invention provides a multi-element coordinated shifting method that maintains topological relationships. This method solves the problems of existing map element shifting methods, which struggle to maintain global topological consistency, dynamic association of multiple elements, resolve conflicts, and strictly maintain topology, ultimately leading to low shifting accuracy.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A multi-element coordinated shift method that preserves topological relationships includes the following steps: S1. Collect raw vector map data, including the boundary point coordinates, feature type, feature level, and topological relationship information between map features. S2. Perform geometric coordinate cleaning on the original vector map data to generate preprocessed vector map data; S3. Based on the preprocessed vector map data, perform topological relationship classification and constraint strength assignment to generate the total constraint strength of each map element; S4. Based on the preprocessed vector map data, the minimum Euclidean distance between the boundary points of each map feature is calculated, and combined with the minimum safe distance between features in the cartographic specification, the conflict degree of any two map features is generated. S5. Based on the total constraint strength of each map element and the conflict degree between any two map elements, the objective function of shifting is to prioritize the adjustment of elements with lower total constraint strength and prioritize the resolution of conflicts between elements with greater conflict. The gradient descent method is used to iteratively solve the problem and generate the optimal shift vector for the map elements to achieve coordinated shifting of map elements.

[0006] The present invention has the following beneficial effects: The multi-element coordinated shift method proposed in this invention, which preserves topological relationships, collects raw data containing boundary point coordinates, element attributes, and topological associations, and generates high-quality preprocessed data through geometric coordinate cleaning. Then, based on the preprocessed data, the topological constraint strength, i.e., the total constraint strength and conflict degree, is quantified. Finally, a shift objective function is constructed with the goal of prioritizing the adjustment of elements with low constraint strength and prioritizing the solution of element pairs with high conflict degree. The optimal shift vector is solved iteratively by the gradient descent method to complete the coordinated shift. This method not only achieves the global optimal shift but also avoids conflict transfer, improves shift efficiency, and ultimately ensures map accuracy and topological integrity. Moreover, it can be adapted to large-scale high-precision map production. Attached Figure Description

[0007] Figure 1 This is a flowchart illustrating a multi-element coordinated shifting method that maintains topological relationships, as proposed in this invention. Detailed Implementation

[0008] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0009] like Figure 1 As shown, a multi-element coordinated shifting method that preserves topological relationships includes the following steps: S1. Collect raw vector map data, including the boundary point coordinates, feature type, feature level, and topological relationship information between map features.

[0010] In this embodiment, a vector map and its raw data are obtained from a cartographic database. This raw data includes geometric coordinate data of each map element (coordinates of boundary points), attribute data of each element (element type, element level, and map scale), and raw topological relationship data (topological association information between map elements). The boundary point coordinates of each map element need to be standardized to the target cartographic scale and projected coordinate system. Attribute data represents the inherent attributes of each map element, used to assist in identifying topological relationship types and map accuracy thresholds, including element type (e.g., roads, plots, buildings), element level (e.g., national level, county level roads), etc. Raw topological relationship data represents the preliminary identified topological association information between map elements. It does not require manual strength determination; it only needs to record whether an association exists and a preliminary representation of the association type, including associated element pairs (e.g., ...). Representing map elements With map elements The data includes data on the existence of relationships and preliminary identification of topological relationship types (such as preliminary classification of inclusion, intersection, adjacency, and no association). These original topological relationship data are automatically identified using the topology inspection tools of GIS software. After the software loads vector data, it can generate a preliminary topological relationship table (topological association information between map features) by checking intersection or inclusion relationships.

[0011] S2. Perform geometric coordinate cleaning on the original vector map data to generate preprocessed original vector map data.

[0012] Specifically, step S2 includes S21-S26: S21. Obtain the boundary point coordinate sequence for each map feature, i.e.:

[0013] in, , Representing map elements respectively The x and y coordinates of boundary point 1, , Representing map elements respectively The x and y coordinates of boundary point 2, , Representing map elements respectively Boundary points The horizontal and vertical coordinates.

[0014] In this embodiment, the boundary point coordinate sequence of each map feature is obtained, thereby providing the necessary data foundation for subsequent geometric coordinate cleaning.

[0015] S22. Based on the coordinate sequence of boundary points for each map feature, calculate the Euclidean distance between two adjacent boundary points of each map feature, i.e.:

[0016]

[0017] in, Representing map elements Adjacent boundary points With boundary points European distance, , Representing map elements Boundary points x-coordinate and y-coordinate , Representing map elements respectively Boundary points x-coordinate and y-coordinate Representing map elements The number of boundary points.

[0018] In this embodiment, by calculating the Euclidean distance between adjacent boundary points, the local changes in map feature boundaries can be quantified; that is, by calculating the boundary points... With boundary points The Euclidean distance measures the spatial span between the two boundary points, which is used for anomaly detection in subsequent steps.

[0019] S23. Based on the Euclidean distance between the two adjacent boundary points of each map feature, obtain the distance sequence composed of the Euclidean distances between the two adjacent boundary points of each map feature, that is:

[0020] in, Representing map elements The distance sequence consisting of the Euclidean distances between each pair of adjacent boundary points. Representing map elements Adjacent boundary point 1 and boundary point European distance, Representing map elements Adjacent boundary points With boundary points Euclidean distance.

[0021] S24. Calculate the mean and standard deviation of the distance series composed of the Euclidean distances between each pair of adjacent boundary points of each map feature.

[0022] In this embodiment, the purpose of calculating the mean and standard deviation of each distance sequence is to grasp the central tendency and dispersion of the distances between adjacent boundary points of map elements as a whole. The mean reflects the average level of the distance between adjacent boundary points and reflects the central tendency of the distance, while the standard deviation reflects the fluctuation of the distance and reflects the dispersion. Therefore, by calculating the standard deviation and mean of each distance sequence, these statistics are used to provide quantitative standards for the subsequent judgment of outliers, making the detection of outliers more objective and scientific.

[0023] S25, Targeting Map Elements The Laida criterion is used to determine the Euclidean distance between two adjacent boundary points of the map feature. Whether the distance is greater than or less than the sum of the mean and standard deviation of its distance sequence; if so, then the boundary point of the map feature. If it is an outlier, proceed to step S26; otherwise, the boundary point of the map feature... The coordinates are correct and should be retained.

[0024] In this embodiment, based on the Raida criterion ( The criteria (using the mean plus three standard deviations) are used to identify outliers, effectively recognizing points on the boundaries of map features that deviate from the normal distance range. These outliers may be caused by measurement errors, data entry errors, etc. Timely identification can prevent these erroneous data from adversely affecting subsequent map feature analysis (feature displacement), ensuring the quality of map feature data. Furthermore, due to Euclidean distance... It describes the boundary points. With boundary points The spatial span between them, based on the Laida criterion, when or When, specify the boundary points With boundary points The distance between them has increased abnormally, and they are more inclined towards the previous boundary point. The position is off, which causes the subsequent boundary point to be off. The distance is abnormal, therefore, when or At that time, the identified outliers should be boundary points. ;in, Representing map elements The mean of the distance sequence formed by the Euclidean distances between each pair of adjacent boundary points. Representing map elements The standard deviation of the distance sequence consisting of the Euclidean distances between each pair of adjacent boundary points.

[0025] S26. Determine the boundary points of the map feature. If the boundary point is the first or last boundary point of the map feature, delete it directly. Otherwise, perform linear interpolation on the two adjacent points of the boundary point and replace the original x and y coordinates of the boundary point with the linear interpolation result to obtain the corrected boundary point.

[0026]

[0027] in, , These represent the x and y coordinates of the corrected boundary points, respectively. , Representing map elements respectively Boundary points The x-coordinate and y-coordinate.

[0028] In this embodiment, for map feature boundary points identified as anomalies, the point is deleted depending on whether it is the first or last boundary point. The purpose is as follows: because the first and last boundary points lack a preceding or following adjacent point, linear interpolation cannot be performed, so they are directly deleted; while anomalies in the middle can be corrected by linear interpolation between adjacent boundary points to ensure the continuity and rationality of the boundary. Therefore, this step corrects anomalies by linear interpolation, which can restore the boundary of map features to a smooth and continuous state, thereby ensuring the accuracy of the geometric shape of map features. This provides high-quality map feature data for subsequent operations such as multi-feature coordinated shifting while maintaining topological relationships, ensuring the accuracy of spatial and topological relationships of map features in subsequent operations.

[0029] S3. Based on the preprocessed vector map data, perform topological relationship classification and constraint strength assignment to generate the total constraint strength of each map element.

[0030] Specifically, step S3 includes S31-S34: S31. Obtain the set of map features to be processed, i.e.:

[0031] in, This represents the set of map features to be processed. , , These represent map element 1, map element 2, and map element respectively. .

[0032] S32. Obtain the topological relationship types between map features. , Representing map elements With map elements The types of topological relationships between them.

[0033] S33, Based on Topological Relationship Type The strength of inherent attributes determines the strength of constraints between map elements. , Representing map elements With map elements The constraint strength between them is as follows: If the topological relationship type To establish an inclusion relationship, assign this map feature a constraint strength of 0. .

[0034] If the topological relationship type To establish an intersection relationship, assign the map feature a constraint strength of 0. .

[0035] If the topological relationship type Assuming an adjacency relationship, assign the map feature a constraint strength of [value]. .

[0036] If the topological relationship type Since there is no correlation, the constraint strength for this map feature is set to 0. .

[0037] In this embodiment, the topological relationship types between map elements include containment, intersection, adjacency, and no association. Based on the inherent strength of these topological relationship types, i.e., containment has the strongest association and no association has the weakest association, map elements with containment, intersection, adjacency, and no association are assigned constraint strength values ​​from largest to smallest in sequence. This transformation of qualitative topological relationship types (containment, intersection, adjacency, no association) into quantitative constraint strength values ​​(3, 2, 1, 0) allows the degree of topological constraint between map elements to be measured numerically, so that subsequent steps can quantify the constraint strength of each map element and thus determine the priority of map element displacement. At the same time, this quantification avoids the subjectivity of manual judgment, making the quantification of map topological relationships and subsequent processing more scientific and operable.

[0038] S34. Based on the constraint strength between map elements Calculate the total constraint strength for each map feature, i.e.:

[0039] in, Representing map elements Total constraint strength, This indicates the total number of map elements.

[0040] In this embodiment, the constraint strength between each map element is considered. The total constraint strength of each map feature is calculated by summing. This allows us to use the total constraint strength to reflect the degree to which a map feature is subject to topological constraints from all other related features. The greater the total constraint strength, the stronger the topological constraints on the map feature. This provides a key quantitative indicator for subsequent feature shift priority determination operations, thereby ensuring that map features follow the strength rules of topological constraints when shifting, while maintaining the rationality of map topological relationships.

[0041] S4. Based on the preprocessed vector map data, the minimum Euclidean distance between the boundary points of each map feature is calculated, and combined with the minimum safe distance between features according to the cartographic specifications, the conflict degree of any two map features is generated.

[0042] In this embodiment, the minimum safe distance between features in the map cartographic specification is the minimum spatial distance that must be maintained between similar or dissimilar features as clearly stipulated in the map cartographic specification. It is related to the map scale and feature type combination, and can be queried through the preset national standard safe distance table via "scale-feature type combination".

[0043] Specifically, step S4 includes S41-S42: S41. Obtain the minimum Euclidean distance between boundary points of each map feature, specifically: Obtain map elements any boundary point to map features The Euclidean distance between any boundary point is used to filter out the smallest Euclidean distance, which is then taken as the minimum Euclidean distance between boundary points of all map features. , Representing map elements Boundary Points to Map Elements The minimum Euclidean distance between boundary points.

[0044] In this embodiment, the minimum Euclidean distance between boundary points of each map feature is the actual minimum distance between the features.

[0045] S42. Based on the minimum Euclidean distance between boundary points of each map feature and the minimum safe distance between features according to cartographic standards, calculate the conflict degree of any two map features, i.e.:

[0046] in, Representing map elements With map elements The degree of conflict This indicates the minimum safe distance between features in a map cartographic standard.

[0047] In this embodiment, the ratio of the minimum Euclidean distance between boundary points of map features to the minimum safe distance between features is used as the conflict degree between map features. This allows subsequent steps to consider the conflict degree of each map feature pair when establishing the shift objective function, prioritizing feature pairs with high conflict as the targets for conflict resolution. Specifically, when... When describing map elements With map elements There is a conflict, meaning the actual distance is less than the safe clearance, requiring relocation. When less than 1 is satisfied, The smaller the size, the greater the conflict; when When describing map elements With map elements There is no conflict, meaning the actual distance meets the safety clearance requirement, and no action is needed.

[0048] S5. Based on the total constraint strength of each map element and the conflict degree between any two map elements, the objective function of shifting is to prioritize the adjustment of elements with lower total constraint strength and prioritize the resolution of conflicts between elements with greater conflict. The gradient descent method is used to iteratively solve the problem and generate the optimal shift vector for the map elements to achieve coordinated shifting of map elements.

[0049] In this embodiment, to achieve coordinated relocation of conflicting elements, a relocation objective function is constructed and iteratively optimized to determine the relocation vector of map elements, combining the overall constraint strength and conflict degree. Specifically, map elements with lower overall constraint strength are adjusted first, and map elements with high conflict are resolved first. The relocation objective function is constructed, and gradient descent is used for iterative optimization to solve for the optimal relocation vector of each map element. This reduces the overall conflict degree while satisfying topological constraints, ultimately achieving coordinated relocation of map elements. The specific operation process is as follows: Specifically, step S5 includes S51-S55: S51. Define the shift vector of map features, that is:

[0050] in, Representing map elements The shift vector, , Representing map elements respectively exist , The amount of displacement in direction.

[0051] In this embodiment, a predefined shift vector for map features is used to construct the shift objective function in subsequent steps.

[0052] S52. Prioritizing adjustments to elements with lower overall constraint strength and resolving conflicts among elements with higher conflict strength, the shift objective function is constructed by minimizing the weighted sum of global conflicts and topological constraint violations.

[0053]

[0054]

[0055] in, This indicates taking the minimum value. Describe the shift objective function. , , These represent map element 1, map element 2, and map element respectively. The shift vector, Indicates map features before displacement With map elements The degree of conflict Indicates map features after displacement With map elements The degree of conflict Representing map elements Shift weights Representing map elements Total constraint strength, Representing map elements Shift weights Representing map elements The total constraint strength; where, , This reflects that the smaller the total constraint strength, the larger the shift weight, and the higher the priority of the element's shift. Reflects map element pairs, i.e., map elements With map elements The overall adjustability between elements with low overall constraint strength makes them easier to coordinate.

[0056] In this embodiment, based on the above steps defining the shift vector of map features and the calculation method for conflict degree, the conflict degree between shifted map features can be calculated, specifically as follows: Assuming the map features are shifted, The coordinates of the boundary points become , Map elements before displacement Boundary points The horizontal and vertical coordinates; based on the above conflict degree calculation method, calculate the map features after displacement. With map elements The degree of conflict, i.e.: , Indicates map features after displacement Boundary Points to Map Elements The minimum Euclidean distance between boundary points; Furthermore, the objective of constructing the shift objective function by minimizing the weighted sum of global conflict and topological constraint violation levels is as follows: Since the shift of elements with low overall constraint strength has a relatively small impact on the overall topology, prioritizing their adjustment makes overall coordination easier; prioritizing the resolution of conflicting element pairs can more efficiently alleviate conflicts between map elements. The concept of "large conflict" is reflected in the parameters... We hope this value is as large as possible, i.e., a large conflict corresponds to... The value is small and less than 1, therefore, the objective function is to minimize the collision degree after the shift. Conflict degree before shift The ratio, i.e., the desired ratio as close as possible or greater than Ultimately, this led to This eliminates the conflict.

[0057] Therefore, when constructing the shift objective function, priority is given to processing feature pairs with high conflict. This can quickly and effectively alleviate severe feature conflicts in the map, avoiding the inefficiency caused by indiscriminate processing and improving the efficiency of conflict resolution. At the same time, the degree of topological constraint violation is considered, so that the original topological relationship between map features can be maintained as much as possible during feature shifting and adjustment, reducing the damage to the topological correctness of map data caused by shifting operations and ensuring the quality of map data. Finally, based on the constructed shift objective function, gradient descent can be used for iterative solution to obtain the optimal shift amount of map features, so as to achieve coordinated shifting of map features.

[0058] S53. The gradient descent method is used to iteratively solve the shift objective function, that is:

[0059] in, Indicates the first Map elements in the next iteration The shift vector, Indicates the first Map elements in the next iteration The shift vector, This indicates the control of the iteration step size, with a value of 0.1. In practical applications, it can be adjusted according to the convergence situation. This indicates that the shift objective function is in the shift vector. The gradient at the point reflects the shift objective function as a function of the shift vector. The changing trend is used to guide the direction of displacement.

[0060] In this embodiment, the gradient descent method is introduced to iteratively solve the displacement objective function, which can more efficiently find the optimal displacement vector that minimizes the displacement objective function, accelerate the calculation process of coordinated displacement of elements, improve the overall processing efficiency, and this method is also applicable to various complex map element distribution scenarios. Whether it is a simple element conflict or a displacement requirement under complex topological constraints between multiple elements, the gradient descent method can be gradually optimized through iteration, which has strong adaptability and can be widely used in map data processing of different scales and different element types. Moreover, it can be fully automated without much human intervention, and can process a large number of map element displacement calculations in batches, reducing the workload of manual operation and human error, and improving the automation level of map data processing.

[0061] S54. Determine whether the shift objective function has converged. If it has, obtain the optimal shift vector for the map features and proceed to step S55. Otherwise, continue to step S53.

[0062] In this embodiment, the shift objective function converges, that is, the change in the objective function is less than a set threshold, and then the iteration process is terminated, and the optimal shift vector is finally obtained. At the same time, the gradient descent method is used, that is, the optimal shift amount is automatically solved by mathematical methods, which avoids the subjectivity of manual intervention and improves the shift accuracy.

[0063] S55. Based on the optimal shift vector of map features, adjust the coordinates of the boundary points of each map feature to achieve coordinated shifting of map features, i.e.:

[0064]

[0065]

[0066] in, Representing map elements The optimal shift vector, , Representing map elements respectively exist , The optimal shift amount in the direction. , These represent the map elements after displacement. Boundary points x and y coordinates , These represent the map elements before the shift. Boundary points The horizontal and vertical coordinates.

[0067] In summary, this step, based on the optimal shift vector, adjusts the coordinates of map feature boundary points, enabling precise shifting of map features. This precision ensures that after shifting, map features not only effectively alleviate conflicts between features but also maintain their original shape, size, and other geometric characteristics to the greatest extent possible, making the spatial relationships on the map more rational. Simultaneously, through coordinated shifting, spatial conflicts between map features can be specifically resolved, allowing conflicting features to be distributed rationally in space while preserving topological relationships and geometric characteristics, improving map readability and aesthetics, and meeting the needs of cartographic standards and practical applications. Secondly, The entire shifting process is automatically completed based on mathematical calculations and optimization algorithms (gradient descent method), requiring minimal manual intervention. This significantly improves the efficiency of map data processing, especially when dealing with large-scale map data. It enables rapid coordinated shifting of multiple elements, saving manpower and time costs. Finally, during the shifting process, because the coordinated adjustment is based on the optimal shift vector, the original topological relationships between map elements (such as adjacency and containment relationships) can be well maintained. This avoids topological errors caused by improper shifting operations, ensuring the topological correctness of the map data and providing a reliable data foundation for subsequent map analysis and applications.

[0068] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

[0069] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A multi-element coordinated shifting method that preserves topological relationships, characterized in that, Includes the following steps: S1. Collect raw vector map data, including the boundary point coordinates, feature type, feature level, and topological relationship information between map features. S2. Perform geometric coordinate cleaning on the original vector map data to generate preprocessed vector map data; S3. Based on the preprocessed vector map data, perform topological relationship classification and constraint strength assignment to generate the total constraint strength of each map element; S4. Based on the preprocessed vector map data, the minimum Euclidean distance between the boundary points of each map feature is calculated, and combined with the minimum safe distance between features in the cartographic specification, the conflict degree of any two map features is generated. S5. Based on the total constraint strength of each map element and the conflict degree between any two map elements, the objective function of shifting is to prioritize the adjustment of elements with lower total constraint strength and prioritize the resolution of conflicts between elements with greater conflict. The gradient descent method is used to iteratively solve the problem and generate the optimal shift vector for the map elements to achieve coordinated shifting of map elements.

2. The multi-element coordinated shifting method that maintains topological relationships according to claim 1, characterized in that, Step S2 specifically includes: S21. Obtain the boundary point coordinate sequence for each map feature, i.e.: in, , Representing map elements respectively The x and y coordinates of boundary point 1, , Representing map elements respectively The x and y coordinates of boundary point 2, , Representing map elements respectively Boundary points The horizontal and vertical coordinates; S22. Based on the coordinate sequence of boundary points for each map feature, calculate the Euclidean distance between two adjacent boundary points of each map feature, i.e.: in, Representing map elements Adjacent boundary points With boundary points European distance, , Representing map elements Boundary points x-coordinate and y-coordinate , Representing map elements respectively Boundary points x-coordinate and y-coordinate Representing map elements The number of boundary points; S23. Based on the Euclidean distance between the two adjacent boundary points of each map feature, obtain the distance sequence composed of the Euclidean distances between the two adjacent boundary points of each map feature, that is: in, Representing map elements The distance sequence consisting of the Euclidean distances between each pair of adjacent boundary points. Representing map elements Adjacent boundary point 1 and boundary point European distance, Representing map elements Adjacent boundary points With boundary points Euclidean distance; S24. Calculate the mean and standard deviation of the distance series composed of the Euclidean distances between each pair of adjacent boundary points of each map feature; S25, Targeting Map Elements The Laida criterion is used to determine the Euclidean distance between two adjacent boundary points of the map feature. Whether the distance is greater than or less than the sum of the mean and standard deviation of its distance sequence; if so, then the boundary point of the map feature. If it is an outlier, proceed to step S26; otherwise, the boundary point of the map feature... The coordinates are correct; please retain them. S26. Determine the boundary points of the map feature. If the boundary point is the first or last boundary point of the map feature, delete it directly. Otherwise, perform linear interpolation on the two adjacent points of the boundary point and replace the original x and y coordinates of the boundary point with the linear interpolation result to obtain the corrected boundary point. in, , These represent the x and y coordinates of the corrected boundary points, respectively. , Representing map elements respectively Boundary points The x-coordinate and y-coordinate.

3. The multi-element coordinated shifting method that maintains topological relationships according to claim 1, characterized in that, Step S3 specifically includes: S31. Obtain the set of map features to be processed, i.e.: in, This represents the set of map features to be processed. , , These represent map element 1, map element 2, and map element respectively. ; S32. Obtain the topological relationship types between map features. , Representing map elements With map elements Topological relationship types between them; S33, Based on Topological Relationship Type The strength of inherent attributes determines the strength of constraints between map elements. , Representing map elements With map elements The constraint strength between them is as follows: If the topological relationship type To establish an inclusion relationship, assign this map feature a constraint strength of 0. ; If the topological relationship type To establish an intersection relationship, assign the map feature a constraint strength of 0. ; If the topological relationship type Assuming an adjacency relationship, assign the map feature a constraint strength of [value]. ; If the topological relationship type Since there is no correlation, the constraint strength for this map feature is set to 0. ; S34. Based on the constraint strength between map elements Calculate the total constraint strength for each map feature, i.e.: in, Representing map elements Total constraint strength, This indicates the total number of map elements.

4. The multi-element coordinated shifting method that maintains topological relationships according to claim 1, characterized in that, Step S4 specifically includes: S41. Obtain the minimum Euclidean distance between boundary points of each map feature, specifically: Obtain map elements any boundary point to map features The Euclidean distance between any boundary point is used to filter out the smallest Euclidean distance, which is then taken as the minimum Euclidean distance between boundary points of all map features. , Representing map elements Boundary Points to Map Elements The minimum Euclidean distance between boundary points; S42. Based on the minimum Euclidean distance between boundary points of each map feature and the minimum safe distance between features according to cartographic specifications, calculate the conflict degree of any two map features, i.e.: in, Representing map elements With map elements The degree of conflict This indicates the minimum safe distance between elements.

5. The multi-element coordinated shifting method that maintains topological relationships according to claim 1, characterized in that, Step S5 specifically includes: S51. Define the shift vector of map features, that is: in, Representing map elements The shift vector, , Representing map elements respectively exist , The amount of displacement in direction; S52. Prioritizing adjustments to elements with lower overall constraint strength and resolving conflicts among elements with higher conflict strength, the shift objective function is constructed by minimizing the weighted sum of global conflicts and topological constraint violations. in, This indicates taking the minimum value. Describe the shift objective function. , , These represent map element 1, map element 2, and map element respectively. The shift vector, Indicates the total number of map features. Indicates map features before displacement With map elements The degree of conflict Indicates map features after displacement With map elements The degree of conflict Representing map elements Shift weights Representing map elements Total constraint strength, Representing map elements Shift weights Representing map elements Total constraint strength; S53. The gradient descent method is used to iteratively solve the shift objective function, that is: in, Indicates the first Map elements in the next iteration The shift vector, Indicates the first Map elements in the next iteration The shift vector, This indicates the control of the iteration step size. This indicates that the shift objective function is in the shift vector. gradient at; S54. Determine whether the shift objective function has converged. If it has, obtain the optimal shift vector for the map element and proceed to step S55. Otherwise, continue to step S53. S55. Based on the optimal shift vector of map features, adjust the coordinates of the boundary points of each map feature to achieve coordinated shifting of map features, i.e.: in, Representing map elements The optimal shift vector, , Representing map elements respectively exist , The optimal shift amount in the direction. , These represent the map elements after displacement. Boundary points x and y coordinates , These represent the map elements before the shift. Boundary points The horizontal and vertical coordinates.

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