Terrain feature analysis method applied to road route selection

Abstract

The invention relates to the technical field of road construction, in particular to a topographic feature analysis method applied to road route selection, which comprises the following steps: acquiring digital topographic information of a road route area needing to be planned; generating a digital terrestrial model; acquiring an outer contour polyline of the digital terrestrial model, and constructing a digital terrestrial model bounding rectangle according to the outer contour polyline; rasterizing the external rectangle of the digital terrestrial model into a plurality of detection areas with preset sizes, and taking a sampling point in each detection area at an interval of a plurality of unit lengths; judging whether each sampling point is located in an outer contour polyline range of the digital terrain model or not, if so, enabling the sampling point to participate in regional topographic feature analysis of the detection region to which the sampling point belongs, and if not, enabling the sampling point not to participate in regional topographic feature analysis of the detection region to which the sampling point belongs; accurate topographic data and analysis results can be provided for highway route design, route passing mountainous areas and areas with large fluctuation degrees are avoided, and the scientificity of decision making is improved.

Description

Technical Field

[0001] The invention relates to the technical field of highway construction, and in particular to a terrain feature analysis method applied to highway route selection. Background Art

[0002] In the professional practice of highway survey and design, choosing a route that meets the requirements is a crucial step, as it will determine the economic benefits, construction difficulty, and future operational benefits of the road project.

[0003] With the development of economy and the acceleration of urbanization, the demand for transportation has increased dramatically. In order to meet the growing transportation demand, new roads need to be built and the existing transportation network needs to be improved. This demand has prompted engineers and planners to seek more efficient methods for highway route selection and design. Many highway construction projects need to cross complex terrains, such as mountains, hills and urban areas. The traditional route selection method is not accurate enough, resulting in less optimized design solutions, which in turn increases construction costs and difficulty. In addition, the project budget is usually limited, and it is necessary to control costs through optimized design, which includes reducing earthwork volume, reducing construction difficulty, and avoiding high construction and maintenance costs.

[0004] In order to meet the complex challenges faced in modern highway construction, it is urgent to propose a method that can accurately analyze terrain characteristics to better provide data and decision support for highway route selection, helping designers, engineers and planners to develop more effective highway construction plans. Summary of the invention

[0005] The purpose of the present invention is to provide route selection decision support for highway route design when facing complex terrain conditions by accurately analyzing the terrain features in the electronic topographic map, avoid the route passing through mountainous areas and areas with large undulations, improve the scientific nature of decision-making, reduce construction difficulty and earthwork volume, thereby controlling project costs, and comprehensively consider environmental factors to reduce the damage of highways to cities.

[0006] To achieve the purpose of the present invention, the following technical solutions are adopted:

[0007] A terrain feature analysis method for highway route selection comprises the following steps:

[0008] Based on digital terrain maps, collect digital terrain information of the area where highway routes need to be planned;

[0009] Generate a digital terrain model based on the digital terrain information as basic data for highway route planning;

[0010] Acquire the outer contour polyline of the digital terrain model, and construct a circumscribed rectangle of the digital terrain model according to the outer contour polyline;

[0011] Rasterizing the circumscribed rectangle of the digital terrain model into a plurality of detection areas of preset sizes, and taking a sampling point every a plurality of unit lengths in each detection area;

[0012] It is determined whether each sampling point is within the outer contour polyline range of the digital terrain model. If so, the sampling point participates in the regional terrain feature analysis of the detection area to which it belongs. Otherwise, the sampling point does not participate in the regional terrain feature analysis of the detection area to which it belongs.

[0013] A further improvement is that the method for determining whether each sampling point is located within the outer contour polyline range of the digital terrain model includes:

[0014] Construct a ray starting from the sampling point to be determined and pointing to the positive direction of the X-axis;

[0015] Calculate the total number of intersections between the ray and each edge of the outer contour polyline;

[0016] If the total number of intersection points is an odd number, the sampling point to be determined is located within the range of the outer contour polyline; if the total number of intersection points is not an odd number, the sampling point to be determined is located outside the range of the outer contour polyline.

[0017] A further improvement is that the regional terrain feature analysis includes determining the degree of undulation of each detection area based on sampling points in each detection area that participate in the regional terrain feature analysis.

[0018] A further improvement is that the method of determining the degree of undulation of each detection area according to the sampling points participating in the regional terrain feature analysis in each detection area includes:

[0019] Assuming that there are N sampling points participating in the regional terrain feature analysis in a certain detection area to be judged, the elevation set corresponding to the N sampling points participating in the regional terrain feature analysis is e1, e2, e3..., and the formula for calculating the undulation degree of the detection area to be judged is as follows:

[0020]

[0021] Among them, μ represents the average elevation of the detection area to be judged;

[0022]

[0023] When σ is less than the first preset parameter value, it means that the fluctuation degree of the detection area to be determined is small, otherwise it means that the fluctuation degree of the detection area to be determined is large.

[0024] A further improvement is that the regional terrain feature analysis includes judging whether each detection area belongs to a hilly area or a basin area according to sampling points participating in the regional terrain feature analysis in each detection area.

[0025] A further improvement is that the method of judging whether each detection area belongs to a hilly area or a basin area according to the sampling points participating in the regional terrain feature analysis in each detection area includes:

[0026] According to the sampling points involved in the regional terrain feature analysis in each detection area, the average elevation of each detection area is calculated separately. Assuming μ A is the average elevation of the detection area A1 to be judged, let:

[0027] G1 = Average elevation of the adjacent detection areas around detection area A1 > μ A The number of detection areas;

[0028] G2 = Average elevation of the adjacent detection areas around detection area A1 ≤ μ A The number of detection areas;

[0029] G3 = G1 / (G1+G2);

[0030] When G3<the second preset parameter value, it is determined that the detection area A1 belongs to a hilly area, and the larger the value of G3 is, the more obvious the hilly feature is;

[0031] When G3≥the second preset parameter value, it is determined that the detection area A1 belongs to a basin area, and the smaller the value of G3 is, the more obvious the basin feature is.

[0032] A further improvement is that the terrain feature analysis method also includes obtaining the contour line of the urban agglomeration area.

[0033] A further improvement is that the method for obtaining the urban agglomeration area contour line includes:

[0034] Step a: Prepare point cloud data representing the urban area;

[0035] Step b: Select any point Q1 in the point cloud data;

[0036] Step c: select a point Q2 adjacent to point Q1, and the Euclidean distance between point Q2 and point Q1 is ≤ the third preset parameter value;

[0037] Step d: Determine two circles with radii of the fourth preset parameter value from point Q1 and point Q2, and the intersection of the two circles is point Q1 and point Q2;

[0038] Step e: Determine whether the line between point Q1 and point Q2 is a boundary line. If one of the two circles does not exist in any point other than points Q1 and Q2 in the point cloud data, the line between point Q1 and point Q2 is determined to be a boundary line, and point Q2 is determined to be a boundary point. Take point Q2 as the new point Q1 and re-execute step c.

[0039] If one of the two circles does not exist in any point in the point cloud data except points Q1 and Q2, the line between points Q1 and Q2 is judged as not a boundary line, and the boundary point set that has been successfully judged is traced back to obtain an urban agglomeration area contour line, and then return to step b to start obtaining a new urban agglomeration area contour line until all points in the point cloud data have executed step c and ended.

[0040] A further improvement is that the digital terrain information includes contour lines and elevation points.

[0041] A further improvement is that the digital terrain model is generated by Autodesk Civil 3D software, and the outer contour polylines of the digital terrain model are obtained through the Autodesk Civil 3D software interface.

[0042] The beneficial effects of the present invention are:

[0043] The present invention can help highway designers to more accurately select highway routes and reduce uncertainties in design and construction by analyzing terrain features in detail and dividing regional types.

[0044] The present invention can reduce earthwork volume and complex construction requirements through effective terrain feature analysis, optimize route design and reduce construction difficulty, thereby shortening construction period, improving engineering efficiency, controlling engineering costs and improving economic benefits.

[0045] The present invention obtains the contour line of the urban agglomeration area through terrain feature analysis, which can effectively avoid the highway route directly passing through the urban agglomeration area, reducing unexpected problems in construction and demolition costs.

[0046] In general, the present invention can provide accurate terrain data and analysis results for highway route design, avoid routes passing through mountainous areas and areas with large undulations, improve the scientific nature of decision-making, reduce construction difficulty and earthwork volume, thereby controlling project costs, and comprehensively consider environmental factors to reduce the damage of highways to cities. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the outer contour polyline and circumscribed rectangle of the digital terrain model in an embodiment of the present invention;

[0048] Figure 2 It is a schematic diagram of the detection area and sampling points in the circumscribed rectangle;

[0049] Figure 3 A schematic diagram for determining whether a sampling point is within the range of the outer contour polyline;

[0050] Figure 4 Schematic diagram of detection area A1 and its surrounding 8 adjacent detection areas;

[0051] Figure 5 It is a schematic diagram of taking point Q1 and point Q2 from the point cloud data;

[0052] Figure 6 It is a schematic diagram of two circles determined by point Q1 and point Q2;

[0053] Figure 7 The figure is a schematic diagram of the urban agglomeration area outline formed by connecting boundary points. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0055] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0056] Please refer to the attached Figure 1 -Attached Figure 7 , the embodiment of the present invention proposes a terrain feature analysis method for highway route selection, such as Figure 1 and Figure 2 As shown, the following steps are included:

[0057] Step 1: Based on the digital topographic map, collect digital terrain information such as contour lines and elevation points of the area where the highway route needs to be planned.

[0058] Step 2: Generate a digital ground model based on the digital terrain information using professional terrain modeling software (such as Autodesk Civil 3D software) as basic data for highway route planning.

[0059] Step 3: Obtain the outer contour polylines (P1, P2, P3...) of the digital terrain model through the Autodesk Civil 3D software interface, and construct a circumscribed rectangle of the digital terrain model according to the outer contour polylines.

[0060] Specifically, the method for constructing the circumscribed rectangle of the digital terrain model according to the outer contour polyline is as follows: the minimum coordinate point MinP and the maximum coordinate point MaxP are calculated according to the coordinate points of the outer contour polyline, and the calculation formula is as follows:

[0061] MinP.x=min(P1.x, P2.x, P3.x, ..);

[0062] MinP.y=min(P1.y, P2.y, P3.y, ..);

[0063] MaxP.x=max(P1.x, P2.x, P3.x, ..);

[0064] MaxP.y=max(P1.y,P2.y,P3.y,..);

[0065] The circumscribed rectangle of the digital terrain model is constructed based on the minimum coordinate point MinP and the maximum coordinate point MaxP.

[0066] Step 4: rasterize the circumscribed rectangle of the digital terrain model into a number of detection areas of preset sizes, and take a sampling point every 10 unit lengths in each detection area. In this embodiment, the size of each detection area is 100*100.

[0067] Step 5: Determine whether each sampling point is within the outer contour polyline range of the digital terrain model. If so, the sampling point participates in the regional terrain feature analysis of the detection area to which it belongs. Otherwise, the sampling point does not participate in the regional terrain feature analysis of the detection area to which it belongs. This can reduce invalid data processing and improve analysis efficiency and accuracy.

[0068] In a feasible solution of the embodiment of the present invention, as Figure 3 As shown, the method for determining whether each sampling point is located within the outer contour polyline range of the digital terrain model includes:

[0069] Construct a ray R starting from the sampling point P0 to be determined and pointing to the positive direction of the X-axis.

[0070] The total number of intersections between the ray R and each edge of the outer contour polyline is calculated.

[0071] If the total number of intersections is an odd number, the sampling point to be determined is located within the range of the outer contour polyline. If the total number of intersections is not an odd number, the sampling point to be determined is outside the range of the outer contour polyline. Figure 3 As shown, the total number of intersections between the sampling point P0 to be determined and the edges of the outer contour polyline is 3, so it can be determined that the sampling point P0 is located within the outer contour polyline range of the digital terrain model.

[0072] In a preferred solution of an embodiment of the present invention, the regional terrain feature analysis includes determining the degree of undulation of each detection area according to sampling points participating in the regional terrain feature analysis in each detection area.

[0073] It can be understood that by calculating the degree of undulation of each detection area, more detailed terrain information can be obtained to help route designers better understand the terrain characteristics of each area.

[0074] Specifically, the method of determining the degree of undulation of each detection area according to the sampling points participating in the regional terrain feature analysis in each detection area includes:

[0075] Assuming that there are N sampling points participating in the regional terrain feature analysis in a certain detection area to be judged, the elevation set corresponding to the N sampling points participating in the regional terrain feature analysis is e1, e2, e3..., and the formula for calculating the undulation degree of the detection area to be judged is as follows:

[0076]

[0077] Wherein, μ represents the average elevation of the detection area to be judged.

[0078]

[0079] When σ is less than the first preset parameter value, it means that the fluctuation degree of the detection area to be determined is small, otherwise it means that the fluctuation degree of the detection area to be determined is large.

[0080] Preferably, in this embodiment, the first preset parameter value is set to 2, which is an artificially determined empirical parameter value, and those skilled in the art can make adjustments according to actual needs.

[0081] In a preferred solution of an embodiment of the present invention, the regional terrain feature analysis includes determining whether each detection area belongs to a hilly area or a basin area according to sampling points participating in the regional terrain feature analysis in each detection area.

[0082] It can be understood that hilly areas usually have a higher range of height variation and a larger standard deviation, indicating that the terrain has some undulations. Basin areas usually have a lower range of height variation and a smaller standard deviation, indicating that the terrain is relatively flat, with the center lower than the periphery.

[0083] Through quantitative analysis, hilly areas and basin areas can be distinguished more accurately, providing more targeted data support for highway route selection. In addition, after clarifying the terrain type, designers can also flexibly adjust the route design plan according to specific conditions, such as selecting a suitable slope in a hilly area and a suitable drainage measure in a basin.

[0084] Specifically, in this embodiment, the method of judging whether each detection area belongs to a hilly area or a basin area according to the sampling points participating in the regional terrain feature analysis in each detection area includes:

[0085] According to the sampling points involved in the regional terrain feature analysis in each detection area, the average elevation of each detection area is calculated separately. Assuming μ A is the average elevation of the detection area A1 to be judged, let:

[0086] G1 = Average elevation of the adjacent detection areas around detection area A1 > μ A The number of detection areas.

[0087] G2 = Average elevation of the adjacent detection areas around detection area A1 ≤ μ A The number of detection areas.

[0088] G3 = G1 / (G1+G2).

[0089] When G3<the second preset parameter value, it is determined that the detection area A1 belongs to a hilly area, and the larger the value of G3 is, the more obvious the hilly feature is.

[0090] When G3≥the second preset parameter value, it is determined that the detection area A1 belongs to a basin area, and the smaller the value of G3 is, the more obvious the basin feature is.

[0091] Preferably, the second preset parameter value is 0.5. Of course, those skilled in the art can make appropriate adjustments to the second preset parameter value according to actual needs.

[0092] like Figure 4 As shown, there are 8 adjacent detection areas around the detection area A1, and the average elevations of the 8 adjacent detection areas are μ1, μ2, μ3, μ4, μ5, μ6, μ7, and μ8 respectively.

[0093] In a preferred solution of an embodiment of the present invention, the terrain feature analysis method further includes obtaining the contour line of the urban agglomeration area.

[0094] Specifically, in this embodiment, the method for obtaining the urban agglomeration area contour line includes:

[0095] Step a: Prepare point cloud data representing the urban area.

[0096] Step b: Select any point Q1 in the point cloud data.

[0097] Step c: Figure 5 As shown, a point Q2 adjacent to point Q1 is selected, and the Euclidean distance between point Q2 and point Q1 is ≤ the third preset parameter value, and the third preset parameter value is preferably 200, that is, point Q2 satisfies

[0098] Step d: Determine two circles with radii equal to a fourth preset parameter value from point Q1 and point Q2, the intersection of the two circles is point Q1 and point Q2, the centers of the two circles are C1 and C2 respectively, and preferably, the fourth preset parameter value is set to 100.

[0099] Step e: Determine whether the line between point Q1 and point Q2 is a boundary line. If one of the two circles does not exist in any point in the point cloud data except points Q1 and Q2, the line between point Q1 and point Q2 is determined to be a boundary line, and point Q2 is determined to be a boundary point. Take point Q2 as the new point Q1 and re-execute step c.

[0100] If one of the two circles does not exist in any point in the point cloud data except points Q1 and Q2, the line between points Q1 and Q2 is judged not to be a boundary line, and the boundary point set that has been successfully judged is traced back to obtain an urban agglomeration area contour line, and then return to step b to start a new urban agglomeration area contour line acquisition until all points in the point cloud data have executed step c. Figure 7 Shown is a schematic diagram of the urban agglomeration area outline formed by connecting boundary points.

[0101] Specifically, the formula for calculating whether one of the two circles does not exist in any point other than points Q1 and Q2 in the point cloud data is: Assume that any point AP satisfies Then point AP exists in the circle with center C1 if Then point AP exists in the circle whose center is C2. Figure 6 The situation shown is that there is no point in the point cloud data except points Q1 and Q2 in the circle with the center C2, so it can be determined that point Q2 is a boundary point.

[0102] The present invention can help highway designers to more accurately select highway routes and reduce uncertainties in design and construction by analyzing terrain features in detail and dividing regional types.

[0103] The present invention can reduce earthwork volume and complex construction requirements through effective terrain feature analysis, optimize route design and reduce construction difficulty, thereby shortening construction period, improving engineering efficiency, controlling engineering costs and improving economic benefits.

[0104] The present invention obtains the contour line of the urban agglomeration area through terrain feature analysis, which can effectively avoid the highway route directly passing through the urban agglomeration area, reducing unexpected problems in construction and demolition costs.

[0105] In general, the present invention can provide accurate terrain data and analysis results for highway route design, avoid routes passing through mountainous areas and areas with large undulations, improve the scientific nature of decision-making, reduce construction difficulty and earthwork volume, thereby controlling project costs, and comprehensively consider environmental factors to reduce the damage of highways to cities.

[0106] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A terrain feature analysis method for highway route selection, characterized in that: The following steps are involved: Based on digital terrain maps, collect digital terrain information of the area where highway routes need to be planned; Generate a digital terrain model based on the digital terrain information as basic data for highway route planning; Acquire the outer contour polyline of the digital terrain model, and construct a circumscribed rectangle of the digital terrain model according to the outer contour polyline; Rasterizing the circumscribed rectangle of the digital terrain model into a plurality of detection areas of preset sizes, and taking a sampling point every a plurality of unit lengths in each detection area; It is determined whether each sampling point is within the outer contour polyline range of the digital terrain model. If so, the sampling point participates in the regional terrain feature analysis of the detection area to which it belongs. Otherwise, the sampling point does not participate in the regional terrain feature analysis of the detection area to which it belongs.

2. A terrain feature analysis method for highway route selection according to claim 1, characterized in that: The method for determining whether each sampling point is within the outer contour polyline range of the digital terrain model includes: Construct a ray starting from the sampling point to be determined and pointing to the positive direction of the X-axis; Calculate the total number of intersections between the ray and each edge of the outer contour polyline; If the total number of intersection points is an odd number, the sampling point to be determined is located within the range of the outer contour polyline; if the total number of intersection points is not an odd number, the sampling point to be determined is located outside the range of the outer contour polyline.

3. The terrain feature analysis method for highway route selection according to claim 1, characterized in that: The regional terrain feature analysis includes determining the degree of undulation of each detection area according to sampling points participating in the regional terrain feature analysis in each detection area.

4. A terrain feature analysis method for highway route selection according to claim 3, characterized in that: Methods for determining the degree of undulation of each detection area based on sampling points participating in the regional terrain feature analysis in each detection area include: Assuming that there are N sampling points participating in the regional terrain feature analysis in a certain detection area to be judged, and the elevation set corresponding to the N sampling points participating in the regional terrain feature analysis is e1, e2, e3..., the formula for calculating the undulation degree of the detection area to be judged is as follows: Among them, μ represents the average elevation of the detection area to be judged; When σ is less than the first preset parameter value, it means that the fluctuation degree of the detection area to be determined is small, otherwise it means that the fluctuation degree of the detection area to be determined is large.

5. The terrain feature analysis method for highway route selection according to claim 1, characterized in that: The regional terrain feature analysis includes determining whether each detection area belongs to a hilly area or a basin area according to sampling points participating in the regional terrain feature analysis in each detection area.

6. A terrain feature analysis method for highway route selection according to claim 5, characterized in that: Methods for determining whether each detection area belongs to a hilly area or a basin area based on sampling points participating in the regional terrain feature analysis in each detection area include: According to the sampling points involved in the regional terrain feature analysis in each detection area, the average elevation of each detection area is calculated separately. Assuming μ A is the average elevation of the detection area A1 to be judged, let: G1 = Average elevation of the adjacent detection areas around detection area A1 > μ A The number of detection areas; G2 = Average elevation of the adjacent detection areas around detection area A1 ≤ μ A The number of detection areas; G3 = G1 / (G1+G2); When G3<the second preset parameter value, it is determined that the detection area A1 belongs to a hilly area, and the larger the value of G3 is, the more obvious the hilly feature is; When G3≥the second preset parameter value, it is determined that the detection area A1 belongs to a basin area, and the smaller the value of G3 is, the more obvious the basin feature is.

7. A terrain feature analysis method for highway route selection according to any one of claims 1 to 6, characterized in that: The terrain feature analysis method also includes obtaining the contour line of the urban agglomeration area.

8. The terrain feature analysis method for highway route selection according to claim 7, characterized in that: The method for obtaining the urban agglomeration area contour line comprises: Step a: Prepare point cloud data representing the urban area; Step b: Select any point Q1 in the point cloud data; Step c: select a point Q2 adjacent to point Q1, and the Euclidean distance between point Q2 and point Q1 is ≤ the third preset parameter value; Step d: Determine two circles with radii of the fourth preset parameter value from point Q1 and point Q2, and the intersection of the two circles is point Q1 and point Q2; Step e: Determine whether the line between point Q1 and point Q2 is a boundary line. If one of the two circles does not exist in any point other than points Q1 and Q2 in the point cloud data, the line between point Q1 and point Q2 is determined to be a boundary line, and point Q2 is determined to be a boundary point. Take point Q2 as the new point Q1 and re-execute step c. If one of the two circles does not exist in any point in the point cloud data except points Q1 and Q2, the line between points Q1 and Q2 is judged as not a boundary line, and the boundary point set that has been successfully judged is traced back to obtain an urban agglomeration area contour line, and then return to step b to start obtaining a new urban agglomeration area contour line until all points in the point cloud data have executed step c and ended.

9. The terrain feature analysis method for highway route selection according to claim 1, characterized in that: The digital terrain information includes contour lines and elevation points.

10. The terrain feature analysis method for highway route selection according to claim 1, characterized in that: The digital terrain model is generated by Autodesk Civil 3D software, and the outer contour polyline of the digital terrain model is obtained through the Autodesk Civil 3D software interface.

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