CAD terrain gradient analysis and daily standard wind speed increase coefficient calculation method

Abstract

The invention discloses a CAD terrain gradient analysis and daily standard wind speed increase coefficient calculation method. The method comprises the steps that all vertexes of a target broken line in a contour line section CAD graph are extracted; according to the slope of a connecting line between two adjacent vertexes, extracting a transition line segment with a changed slope; calculating the height difference of the i-th transition line segment and the included angle between the i-th transition line segment and the vertical auxiliary line; calculating a first coefficient, a second coefficient and a third coefficient; and calculating a daily standard wind speed increase coefficient corresponding to the i-th transition line segment according to the sum. The method solves the problems that in CAD topographic map design, when line segments with changed gradients in broken lines of a contour profile map are manually extracted, batch processing of the broken lines is needed, time is wasted, and efficiency is low; meanwhile, the prior art lacks the function of automatically calculating the wind speed increase coefficient under the daily standard specification.

Description

Technical Field

[0001] This invention relates to the field of engineering CAD design technology, specifically a method for CAD terrain slope analysis and calculation of the daily wind speed increase coefficient. Background Technology

[0002] In the process of topographic map design using CAD software, users typically need to manually divide the polylines in the contour profile into multiple segments and analyze the slope changes of each segment to identify those with varying slopes. When faced with the need to process multiple polylines in batches, this manual operation consumes significant time and manpower, resulting in low overall efficiency in slope analysis. Furthermore, even after slope analysis, current technology lacks an automatic calculation function for the wind speed increase coefficient required by Japanese standards, making it difficult to meet the accurate calculation requirements of Japanese wind loads in real-world engineering scenarios, thus impacting the efficiency and accuracy of engineering design. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention proposes a method for analyzing CAD terrain slope and calculating the Japanese standard wind speed increase coefficient. The aim is to solve the problem of time-consuming and inefficient batch processing of polylines in CAD topographic map design when manually extracting segments with varying slopes from contour profiles. Furthermore, existing technologies lack automatic calculation functions for the Japanese standard wind speed increase coefficient, thus failing to meet the requirements for calculating Japanese standard wind loads in engineering projects.

[0004] To achieve this objective, the present invention adopts the following technical solution: A method for CAD terrain slope analysis and calculation of the daily wind speed increase coefficient includes the following steps: Step S1: Extract the target polyline from the contour profile CAD drawing, and extract all vertex data from the target polyline; Step S2: Calculate the slope of the line connecting two adjacent vertices in the target polyline, and determine whether the absolute value of the slope is greater than or equal to the preset slope threshold. If yes, the line connecting the two adjacent vertices is determined to be a slope-changing line segment; otherwise, the line connecting the two adjacent vertices is determined to be a flat line segment. Step S3: Traverse all slope change segments and flat segments in top-to-bottom order. During the traversal, if there are at least two slope change segments that are continuously connected, extract the starting vertex of the first slope change segment and the ending vertex of the last slope change segment, and connect these two vertices to form a transition segment; if there is any slope change segment that is directly connected to a flat segment, then determine the slope change segment as a transition segment. Step S4: Calculate the height difference of the i-th transition segment. and the angle between the i-th transition segment and the vertical auxiliary line. ; Step S5: According to The first coefficient is calculated based on the value of . Second coefficient and the third coefficient ; Step S6: According to , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated.

[0005] Preferably, step S1 further includes the following steps: counting the total number of vertices of the target polyline and determining whether the total number of vertices of the target polyline is greater than or equal to a preset target point number threshold. If yes, then steps S2-S6 are executed; if no, then the vertices in the target polyline are extracted again.

[0006] Preferably, in step S4, the height difference of the i-th transition segment is calculated. Specifically, it includes the following sub-steps: Step S41: Construct vertical auxiliary lines and set the extension direction of the vertical auxiliary lines as the x-axis direction; Step S42: Obtain the x-axis coordinates of the starting vertex of the i-th transition segment. and the x-coordinate of the terminating vertex ; Step S43: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] and Perform the difference operation to obtain the height difference of the i-th transition segment. ; The angle between the i-th transition line segment and the vertical auxiliary line Specifically, it includes the following sub-steps: Step S44: Obtain the y-axis coordinate of the starting vertex of the i-th transition segment. and the y-coordinate of the terminating vertex ; Step S45: According to , , and The slope of the i-th transition segment is calculated. ,in, The specific calculation formula is as follows: ; Step S46: According to Using trigonometric functions, the angle between the i-th transition segment and the vertical auxiliary line can be calculated. .

[0007] Preferably, step S5 specifically includes the following sub-steps: when hour, =1.6, , =-2; when hour, , , =-2; when hour, , , ; when hour, =1.3, =1.45, =0.3.

[0008] Preferably, step S6 specifically includes the following sub-steps: Step S71: Obtain the terrain surface roughness category corresponding to the i-th transition line segment, and determine the height parameter corresponding to the terrain surface roughness of the i-th transition line segment based on the category. ; Step S72: According to , , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated. ,in, The specific calculation formula is as follows: +1; Here, exp(.) represents the exponential function.

[0009] Preferably, the method further includes the following steps: setting terrain data annotation rules, wherein the terrain data annotation rules specifically include: using green lines to mark transition segments; , , , , and The information is marked in the right area of ​​the corresponding transition line segment; , , , , and The text color of the annotation is set to green; , , , , and The information is annotated using MText multiline text format; according to the terrain data annotation rules, transition segments, , , , , as well as Perform visual annotation.

[0010] The technical solution provided by this invention may include the following beneficial effects: This solution extracts all vertex data of the target polyline in the contour profile CAD drawing and combines this with slope analysis of the lines connecting adjacent vertices to automatically extract transition segments with varying slopes. When faced with batch processing requirements for multiple polylines, compared to the traditional manual method of obtaining slope-varying segments from contour profile polylines, this solution employs automation, effectively saving significant time and manpower costs and improving the overall efficiency of slope analysis. Furthermore, this solution calculates the angle between the i-th transition segment and the vertical auxiliary line. The height difference of the i-th transition segment First coefficient Second coefficient and the third coefficient Based on the above parameters, the wind speed increase coefficient is automatically calculated, thereby accurately meeting the calculation requirements of the standard wind load in actual engineering scenarios. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the steps involved in a CAD terrain slope analysis and calculation of the daily wind speed increase coefficient. Detailed Implementation

[0012] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0013] A method for CAD terrain slope analysis and calculation of the daily wind speed increase coefficient includes the following steps: Step S1: Extract the target polyline from the contour profile CAD drawing, and extract all vertex data from the target polyline; Step S2: Calculate the slope of the line connecting two adjacent vertices in the target polyline, and determine whether the absolute value of the slope is greater than or equal to the preset slope threshold. If yes, the line connecting the two adjacent vertices is determined to be a slope-changing line segment; otherwise, the line connecting the two adjacent vertices is determined to be a flat line segment. Step S3: Traverse all slope change segments and flat segments in top-to-bottom order. During the traversal, if there are at least two slope change segments that are continuously connected, extract the starting vertex of the first slope change segment and the ending vertex of the last slope change segment, and connect these two vertices to form a transition segment; if there is any slope change segment that is directly connected to a flat segment, then determine the slope change segment as a transition segment. Step S4: Calculate the height difference of the i-th transition segment. and the angle between the i-th transition segment and the vertical auxiliary line. ; Step S5: According to The first coefficient is calculated based on the value of . Second coefficient and the third coefficient ; Step S6: According to , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated.

[0014] This solution presents a method for CAD terrain slope analysis and calculation of the daily wind speed increase coefficient, such as... Figure 1As shown, the first step is to extract the target polyline from the contour profile CAD drawing and extract all vertex data from the target polyline. In this embodiment, by extracting all vertex data from the target polyline in the contour profile CAD drawing, accurate and complete basic data support is provided for subsequent slope analysis. The second step is to calculate the slope of the line connecting two adjacent vertices in the target polyline and determine whether the absolute value of the slope is greater than or equal to a preset slope threshold. If so, the line connecting the two adjacent vertices is determined to be a slope change segment; otherwise, it is determined to be a flat segment. In this embodiment, the preset slope threshold is 0.001. By calculating the slope of the line connecting two adjacent vertices in the target polyline, the inclination of each segment in the target polyline can be accurately quantified, thereby efficiently and objectively analyzing the slope change characteristics of each segment in the target polyline. By comparing the absolute value of the slope of the line connecting two adjacent vertices in the target polyline with a preset slope threshold of 0.001, misjudgments caused by precision errors in floating-point calculations can be accurately avoided, thus ensuring the accuracy and stability of the slope attribute determination results. The third step is to traverse all slope change segments and flat segments in top-to-bottom order. During the traversal, if at least two slope change segments are continuously connected, the starting vertex of the first slope change segment and the ending vertex of the last slope change segment are extracted, and these two vertices are connected to form a transition segment. If any slope change segment is directly connected to a flat segment, that slope change segment is identified as a transition segment. In this embodiment, by extracting and identifying transition segments, slope areas in the terrain can be accurately identified. These areas are key areas that cause wind load changes. This design provides accurate regional positioning basis for the subsequent calculation of the daily wind speed increase coefficient. The fourth step is to calculate the height difference of the i-th transition segment. and the angle between the i-th transition segment and the vertical auxiliary line. In this embodiment, through calculation and This allows for the quantitative characterization of the terrain undulations corresponding to the transition line segment, providing a data foundation for the subsequent calculation of the daily wind speed increase coefficient. The fifth step is based on... The first coefficient is calculated based on the value of . Second coefficient and the third coefficient In this embodiment, due to different The mechanism and extent of the impact of terrain steepness on wind speed also vary, depending on the terrain's steepness. Calculate the corresponding first coefficient based on the value of . Second coefficient and the third coefficient This can accurately reflect the correlation between the steepness of the terrain and the wind speed influence coefficient. The sixth step is based on... , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated. In this embodiment, it is obtained by calculating the coefficient based on the following: , , and The calculation of the target wind speed increase coefficient can quantitatively correlate the geometric features of terrain undulations with the wind speed influence coefficient, thus achieving accurate calculation of the wind speed increase coefficient.

[0015] This solution extracts all vertex data of the target polyline in the contour profile CAD drawing and combines this with slope analysis of the lines connecting adjacent vertices to automatically extract transition segments with varying slopes. When faced with batch processing requirements for multiple polylines, compared to the traditional manual method of obtaining slope-varying segments from contour profile polylines, this solution employs automation, effectively saving significant time and manpower costs and improving the overall efficiency of slope analysis. Furthermore, this solution calculates the angle between the i-th transition segment and the vertical auxiliary line. The height difference of the i-th transition segment First coefficient Second coefficient and the third coefficient Based on the above parameters, the wind speed increase coefficient is automatically calculated, thereby accurately meeting the calculation requirements of the standard wind load in actual engineering scenarios.

[0016] Preferably, step S1 further includes the following steps: counting the total number of vertices of the target polyline, and determining whether the total number of vertices of the target polyline is greater than or equal to a preset target point number threshold. If yes, then steps S2-S6 are executed; if no, then the vertices in the target polyline are re-extracted. In this embodiment, the preset target point number threshold is 3. By performing threshold verification on the total number of vertices of the target polyline, it is ensured that the data used for subsequent terrain slope analysis has sufficient completeness, thereby avoiding a decrease in the accuracy of terrain slope analysis results due to insufficient vertex count.

[0017] Preferably, in step S4, the height difference of the i-th transition segment is calculated. Specifically, it includes the following sub-steps: Step S41: Construct vertical auxiliary lines and set the extension direction of the vertical auxiliary lines as the x-axis direction; Step S42: Obtain the x-axis coordinates of the starting vertex of the i-th transition segment. and the x-coordinate of the terminating vertex ; Step S43: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] and Perform the difference operation to obtain the height difference of the i-th transition segment. ; The angle between the i-th transition line segment and the vertical auxiliary line Specifically, it includes the following sub-steps: Step S44: Obtain the y-axis coordinate of the starting vertex of the i-th transition segment. and the y-coordinate of the terminating vertex ; Step S45: According to , , and The slope of the i-th transition segment is calculated. ,in, The specific calculation formula is as follows: ; Step S46: According to Using trigonometric functions, the angle between the i-th transition segment and the vertical auxiliary line can be calculated. .

[0018] In this embodiment, in step S41, by setting the extension direction of the vertical auxiliary line as the x-axis direction, the calculation benchmark for the height difference can be effectively unified. In step S42, by obtaining the x-axis coordinates of the starting and ending vertices of the transition line segment, data support is provided for the subsequent quantitative calculation of the height difference. In step S43, the height difference is obtained by performing a difference operation on the x-axis coordinates of the starting and ending vertices of the transition line segment; the calculation logic is simple and efficient. In step S44, by obtaining the y-axis coordinates of the starting and ending vertices of the transition line segment, a data basis is provided for the subsequent calculation of the slope of the transition line segment. In step S45, by calculating the slope of the transition line segment based on the coordinates of the starting and ending vertices, the degree of inclination of the transition line segment is quantitatively characterized. In step S46, by calculating the angle between the transition line segment and the vertical auxiliary line based on the slope of the transition line segment and trigonometric function relationships, a quantitative index of terrain steepness is provided for the subsequent calculation of the wind speed increase coefficient.

[0019] Preferably, step S5 specifically includes the following sub-steps: when hour, =1.6, , =-2; when hour, , , =-2; when hour, , , ; when hour, =1.3, =1.45, =0.3.

[0020] In this embodiment, when hour, and All use fixed values. A linear function form is adopted to adapt to scenarios with steep terrain, ensuring the stability of coefficients and computational efficiency within this interval. When as well as hour, , and Both calculations employ a "baseline value + interval proportion correction term" method to achieve a smooth transition of coefficients at the critical points between adjacent intervals, better reflecting the wind speed influence pattern corresponding to gradual changes in terrain steepness. hour, , and All values ​​are fixed to adapt to relatively flat terrain and simplify the calculation logic in flat terrain.

[0021] Preferably, step S6 specifically includes the following sub-steps: Step S71: Obtain the terrain surface roughness category corresponding to the i-th transition line segment, and determine the height parameter corresponding to the terrain surface roughness of the i-th transition line segment based on the category. ; Step S72: According to , , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated. ,in, The specific calculation formula is as follows: +1; Here, exp(.) represents the exponential function.

[0022] In this embodiment, in step S71, the terrain surface roughness category of the i-th transition line segment is first obtained, and then its corresponding height parameter is determined to ensure that the basic data for calculating the subsequent daily wind speed increase coefficient conforms to the actual terrain conditions. Further, when the terrain surface roughness category corresponding to the i-th transition line segment is Class I-III, then... The value of is 5; when the terrain surface roughness category corresponding to the i-th transition line segment is Class IV, then The value is 10. In step S72, by according to , , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated. It can accurately quantify the impact of terrain on wind speed.

[0023] Preferably, the method further includes the following steps: setting terrain data annotation rules, wherein the terrain data annotation rules specifically include: using green lines to mark transition segments; , , , , and The information is marked in the right area of ​​the corresponding transition line segment; , , , , and The text color of the annotation is set to green; , , , , and The information is annotated using MText multiline text format; according to the terrain data annotation rules, transition segments, , , , , as well as Perform visual annotation.

[0024] In this embodiment, during the process of setting terrain data annotation rules, green lines are used to mark transition segments, thereby achieving visual differentiation between transition segments and other terrain segments; by... , , , , and The information labels are placed in the right-hand area of ​​the corresponding transition segment, making it easy for operators to quickly view the associated parameters of the transition segment; by... , , , , and The annotation text color is set to green to unify the annotation text color with the transition line segment color, further strengthening the binding relationship between the transition line segment and the corresponding associated information; by... , , , , and The information is annotated using MText multi-line text format, which can adapt to the layout requirements of multiple annotation parameters and avoid readability confusion caused by stacked annotation parameters. This is achieved through the use of transition lines, , , , , as well as Visual annotations make it easier for operators to clearly and intuitively understand the line segments with changing slopes and their associated parameters.

[0025] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0026] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for CAD terrain slope analysis and calculation of daily wind speed increase coefficient, characterized in that: Includes the following steps: Step S1: Extract the target polyline from the contour profile CAD drawing, and extract all vertex data from the target polyline; Step S2: Calculate the slope of the line connecting two adjacent vertices in the target polyline, and determine whether the absolute value of the slope is greater than or equal to the preset slope threshold. If yes, the line connecting the two adjacent vertices is determined to be a slope-changing line segment; otherwise, the line connecting the two adjacent vertices is determined to be a flat line segment. Step S3: Traverse all slope change segments and flat segments in top-to-bottom order. During the traversal, if there are at least two slope change segments that are continuously connected, extract the starting vertex of the first slope change segment and the ending vertex of the last slope change segment, and connect these two vertices to form a transition segment; if there is any slope change segment that is directly connected to a flat segment, then determine the slope change segment as a transition segment. Step S4: Calculate the height difference of the i-th transition segment. and the angle between the i-th transition segment and the vertical auxiliary line. ; Step S5: According to The first coefficient is calculated based on the value of . Second coefficient and the third coefficient ; Step S6: According to , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated.

2. The method for CAD terrain slope analysis and calculation of daily wind speed increase coefficient according to claim 1, characterized in that: Step S1 also includes the following steps: Count the total number of vertices of the target polyline and determine whether the total number of vertices of the target polyline is greater than or equal to the preset target point number threshold. If yes, proceed with steps S2-S6; otherwise, re-extract the vertices from the target polyline.

3. The method for CAD terrain slope analysis and calculation of daily wind speed increase coefficient according to claim 1, characterized in that: In step S4, the height difference of the i-th transition segment is calculated. Specifically, it includes the following sub-steps: Step S41: Construct vertical auxiliary lines and set the extension direction of the vertical auxiliary lines as the x-axis direction; Step S42: Obtain the x-axis coordinates of the starting vertex of the i-th transition segment. and the x-coordinate of the terminating vertex ; Step S43: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] and Perform the difference operation to obtain the height difference of the i-th transition segment. ; The angle between the i-th transition line segment and the vertical auxiliary line Specifically, it includes the following sub-steps: Step S44: Obtain the y-axis coordinate of the starting vertex of the i-th transition segment. and the y-coordinate of the terminating vertex ; Step S45: According to , , and The slope of the i-th transition segment is calculated. ,in, The specific calculation formula is as follows: ； Step S46: According to Using trigonometric functions, the angle between the i-th transition segment and the vertical auxiliary line can be calculated. .

4. The method for CAD terrain slope analysis and calculation of daily wind speed increase coefficient according to claim 1, characterized in that: Step S5 specifically includes the following sub-steps: when hour, =1.6, , =-2; when hour, , , =-2; when hour, , , ; when hour, =1.3, =1.45, =0.

3.

5. The method for CAD terrain slope analysis and calculation of daily wind speed increase coefficient according to claim 1, characterized in that: Step S6 specifically includes the following sub-steps: Step S71: Obtain the terrain surface roughness category corresponding to the i-th transition line segment, and determine the height parameter corresponding to the terrain surface roughness of the i-th transition line segment based on the category. ; Step S72: According to , , , and The daily wind speed increase coefficient corresponding to the i-th transition line segment is calculated. ,in, The specific calculation formula is as follows: +1； Here, exp(.) represents the exponential function.

6. The method for CAD terrain slope analysis and calculation of daily wind speed increase coefficient according to claim 1, characterized in that: It also includes the following steps: Set terrain data annotation rules, which specifically include: Transition segments are marked with green lines; , , , , and The information is marked in the right area of ​​the corresponding transition line segment; , , , , and The text color of the annotation is set to green; , , , , and The information is annotated using MText multiline text format; According to the terrain data annotation rules, transition segments, , , , , as well as Perform visual annotation.

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