阅读说明：本技术 基于不规则三角网的线路横断面自动提取方法 (Automatic line cross section extraction method based on irregular triangulation network ) 是由 陈泽远 许张柱 王宾宾 张先文 金鸿 张斌 杨宏宝 范靖岘 于 2020-06-28 设计创作，主要内容包括：本发明涉及一种基于不规则三角网的线路横断面自动提取方法,所述方法首先确定线路断面里程的坐标、切线和横断面方向,然后利用ArcGIS Object API实现在不规则三角网模型上提取点高程,最后输出文本形式的断面数据和曲线图。本发明能够自动计算里程点的坐标、切线和横断面方向,按固定间隔提取高程数据,使用者只需要少量的内业数据准备工作便可快速获取断面数据并自动绘图。这不仅改变了传统方式的作业模式,将大量的野外作业转移到室内,避免了野外安全事故的发生,同时也提高了工作效率。(The invention relates to an automatic line cross section extraction method based on an irregular triangulation network. The invention can automatically calculate the coordinate, the tangent line and the cross section direction of the mileage point, extract elevation data according to fixed intervals, and a user can quickly acquire section data and automatically draw by only needing a small amount of homework data preparation work. The method changes the operation mode of the traditional mode, transfers a large amount of field operation to the indoor, avoids the occurrence of field safety accidents, and simultaneously improves the working efficiency.)

1. The automatic extraction method of the line cross section based on the irregular triangulation network is characterized by comprising the following steps:

The method comprises the steps of firstly determining coordinates, tangents and cross section directions of mileage of a line cross section, then utilizing three-dimensional display and analysis functions of ArcGIS software to extract the elevation of an irregular triangulation network, and finally outputting section data and a curve graph in a text form.

2. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 1, wherein:

the method specifically comprises the following steps:

step 1: obtaining an irregular triangulation network model;

step 2: preparing a line configuration file and a section mileage file;

and 3, step 3: importing an irregular triangulation network model;

and 4, step 4: extracting a section;

and 5, step 5: deriving section data;

and 6, step 6: drawing a section curve chart.

3. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 2, wherein:

the step 1 specifically comprises the following steps:

an irregular triangulation network model is generated based on photogrammetry, oblique photogrammetry, or LiDAR data.

4. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 3, wherein:

the step 2 specifically comprises the following steps:

calculating coordinates of the mileage points by using an intersection method or a line element method; when curve elements exist, an intersection point method is adopted, otherwise, a line element method is adopted;

Before data processing, an intersection normal line configuration file or a line element normal line configuration file needs to be prepared;

the section mileage file records the mileage and the left and right ranges of the cross section to be automatically extracted, and the sections are extracted one by one according to the mileage in the file.

5. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 4, wherein:

the step 3 specifically comprises the following steps:

creating a MultiPath element class, then importing an irregular triangulation model into the element class, and finally creating a layer by the element class and adding the layer into a view window for displaying.

6. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 5, wherein:

the step 4 specifically comprises the following steps:

firstly, ensuring that an irregular triangulation network graph layer is in a visible state, then reading in a route configuration file and a section mileage file, sequentially traversing each mileage by software, and calculating coordinates, tangents and cross section direction lines of the mileage; the cross section extraction process of one mileage is as follows:

(1) judging whether the mileage is in a configuration interval or not according to the line configuration file, if the mileage exceeds the configuration interval, recording an error log, and continuously extracting the section of the next mileage;

(2) If the coordinates of the mileage can be calculated, continuously calculating the tangent line and the cross section line of the mileage according to the configuration file;

(3) on the cross section line, calculating the plane coordinates of the sampling points from the position of the mileage point of the line to the left and the right respectively according to the left and the right ranges and the sampling intervals of the mileage section, and calculating and storing the elevation of the line by an elevation interpolation method provided by ArcGIS Object according to the plane coordinates of the sampling points;

and (4) repeating the steps (1) to (3) until cross section sampling and elevation calculation of all the mileage are completed.

7. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 6, wherein:

the step 5 specifically comprises the following steps:

and (4) exporting cross section data in a text form, wherein the file contains the coordinates and the elevation of the sampling point of each mileage.

8. The method for automatically extracting the cross section of the line based on the irregular triangulation network as claimed in claim 7, wherein:

the step 6 specifically comprises the following steps:

reading in the section data exported in the step 5, creating a multi-segment line graph layer and a text graph layer, drawing curves and coordinate axes in the multi-segment line graph layer, and adding characters in the text graph layer.

Technical Field

The invention belongs to the field of line engineering survey, and particularly relates to an automatic line cross section extraction method based on an irregular triangulation network.

Background

In linear engineering, such as surveying of railways and highways, cross-sectional mapping along a line is an important aspect of primary determination. The traditional mapping method adopts a total station or a GPS-RTK field to acquire coordinates and elevations of points on an actual cross section, but mapping is achieved in an interior industry, and the method consumes a large amount of manpower and has low automation degree.

Irregular Triangulated Network (TIN) models, which are commonly used to construct digital ground models, particularly digital elevation models, use a series of connected triangles to fit the earth's surface or other Irregular surfaces, and are shown in fig. 1.

With the continuous development of the mapping technology, a non-contact and efficient sensing measurement mode is continuously developed and widely applied to line surveying, for example, the technologies such as unmanned aerial vehicle aerial photogrammetry, unmanned aerial vehicle oblique photogrammetry, unmanned aerial vehicle airborne LiDAR and the like can be used for easily acquiring images or point clouds of a target area, and an irregular triangulation network model can be generated according to a certain algorithm. The irregular triangulation network model can be used as a digital earth surface model of a target area, the existing photogrammetry and point cloud processing software is general software, has no service function for line engineering and does not support secondary development, and GIS software can realize the import, export and analysis of the irregular triangulation network.

Disclosure of Invention

The invention aims to provide an automatic line cross section extraction method based on an irregular triangulation network, which reduces field survey work and improves cross section measurement efficiency. The method can calculate the coordinates, the tangent lines and the cross section direction of the section mileage points by respectively using an intersection point method and a line element method, carries out secondary development based on ArcGIS Object, and realizes related elevation calculation by using the model display and analysis functions of ArcGIS software.

The technical scheme adopted by the invention is as follows:

the automatic extraction method of the line cross section based on the irregular triangulation network is characterized by comprising the following steps:

the method comprises the steps of firstly determining coordinates, tangents and cross section directions of mileage of a line cross section, then utilizing three-dimensional display and analysis functions of ArcGIS software to extract the elevation of an irregular triangulation network, and finally outputting section data and a curve graph in a text form.

The method specifically comprises the following steps:

step 1: obtaining an irregular triangulation network model;

step 2: preparing a line configuration file and a section mileage file;

and 3, step 3: importing an irregular triangulation network model;

and 4, step 4: extracting a section;

and 5, step 5: deriving section data;

and 6, step 6: drawing a section curve chart.

The step 1 specifically comprises the following steps:

an irregular triangulation network model is generated based on photogrammetry, oblique photogrammetry, or LiDAR data.

The step 2 specifically comprises the following steps:

calculating coordinates of the mileage points by using an intersection method or a line element method; when curve elements exist, an intersection point method is adopted, otherwise, a line element method is adopted;

before data processing, an intersection normal line configuration file or a line element normal line configuration file needs to be prepared;

the section mileage file records the mileage and the left and right ranges of the cross section to be automatically extracted, and the sections are extracted one by one according to the mileage in the file.

The step 3 specifically comprises the following steps:

creating a MultiPath element class, then importing an irregular triangulation model into the element class, and finally creating a layer by the element class and adding the layer into a view window for displaying.

The step 4 specifically comprises the following steps:

firstly, ensuring that an irregular triangulation network graph layer is in a visible state, then reading in a route configuration file and a section mileage file, sequentially traversing each mileage by software, and calculating coordinates, tangents and cross section direction lines of the mileage; the cross section extraction process of one mileage is as follows:

(1) judging whether the mileage is in a configuration interval or not according to the line configuration file, if the mileage exceeds the configuration interval, recording an error log, and continuously extracting the section of the next mileage;

(2) if the coordinates of the mileage can be calculated, continuously calculating the tangent line and the cross section line of the mileage according to the configuration file;

(3) on the cross section line, calculating the plane coordinates of the sampling points from the position of the mileage point of the line to the left and the right respectively according to the left and the right ranges and the sampling intervals of the mileage section, and calculating and storing the elevation of the line by an elevation interpolation method provided by ArcGIS Object according to the plane coordinates of the sampling points;

and (4) repeating the steps (1) to (3) until cross section sampling and elevation calculation of all the mileage are completed.

The step 5 specifically comprises the following steps:

and (4) exporting cross section data in a text form, wherein the file contains the coordinates and the elevation of the sampling point of each mileage.

The step 6 specifically comprises the following steps:

reading in the section data exported in the step 5, creating a multi-segment line graph layer and a text graph layer, drawing curves and coordinate axes in the multi-segment line graph layer, and adding characters in the text graph layer.

The invention has the following advantages:

the software developed by the invention can automatically calculate the coordinate, the tangent line and the cross section direction of the mileage point, and extract elevation data on the irregular triangulation network model at fixed intervals along the section line direction, so that a user can quickly acquire section data and automatically draw by only needing a small amount of internal data preparation work. The method changes the operation mode of the traditional mode, transfers a large amount of field operation to the indoor, avoids the occurrence of field safety accidents, and simultaneously improves the working efficiency.

Drawings

FIG. 1: irregular triangulation network (TIN) schematic.

FIG. 2: and automatically extracting a flow chart based on the cross section of the line of the irregular triangulation network.

FIG. 3: mileage tangent and cross-sectional line graphs. (in the figure, 4, 5 and 6 are mileage marks along the line)

FIG. 4: the cross section is provided with sampling points at fixed intervals.

Detailed Description

The present invention will be described in detail with reference to specific embodiments.

The invention relates to an automatic line cross section extraction method based on an irregular triangulation network.

The method specifically comprises the following steps:

step 1: obtaining an irregular triangulation network model;

step 2: preparing a line configuration file and a section mileage file;

and 3, step 3: importing an irregular triangulation network model;

and 4, step 4: extracting a section;

and 5, step 5: deriving section data;

and 6, step 6: drawing a section curve chart.

The step 1 specifically comprises the following steps:

an irregular triangulation network model is generated based on photogrammetry, oblique photogrammetry, or LiDAR data.

The step 2 specifically comprises the following steps:

the coordinates of the mileage points are calculated by using an intersection point method or a line element method, when curve elements exist, the intersection point method is adopted, otherwise, the line element method is adopted;

before data processing, an intersection normal route configuration file or a line element normal route configuration file needs to be prepared.

The section mileage file records the mileage and the left and right ranges of the cross section to be automatically extracted, and the sections are extracted one by one according to the mileage in the file.

The step 3 specifically comprises the following steps:

creating a MultiPath element class, then importing an irregular triangulation model into the element class, and finally creating a layer by the element class and adding the layer into a view window for displaying.

The step 4 specifically comprises the following steps:

firstly, ensuring that an irregular triangulation network graph layer is in a visible state, then reading in a route configuration file and a section mileage file, sequentially traversing each mileage by software, and calculating coordinates, tangents and cross section direction lines of the mileage; the cross section extraction process of one mileage is as follows:

(1) judging whether the mileage is in a configuration interval or not according to the line configuration file, if the mileage exceeds the configuration interval, recording an error log, and continuously extracting the section of the next mileage;

(2) if the coordinates of the mileage can be calculated, continuously calculating the tangent line and the cross section line of the mileage according to the configuration file;

(3) on the cross section line, calculating the plane coordinates of the sampling points from the position of the mileage point of the line to the left and the right respectively according to the left and the right ranges and the sampling intervals of the mileage section, and calculating and storing the elevation of the line by an elevation interpolation method provided by ArcGIS Object according to the plane coordinates of the sampling points;

and (4) repeating the steps (1) to (3) until cross section sampling and elevation calculation of all the mileage are completed.

The step 5 specifically comprises the following steps:

and (4) exporting cross section data in a text form, wherein the file contains the coordinates and the elevation of the sampling point of each mileage.

The step 6 specifically comprises the following steps:

reading in the section data exported in the step 5, creating a multi-segment line graph layer and a text graph layer, drawing curves and coordinate axes in the multi-segment line graph layer, and adding characters in the text graph layer.

See the flow chart of fig. 2:

the method comprises the following specific steps:

step 1: obtaining an irregular triangulation network model

With the development and popularization of unmanned aerial vehicle technology, photogrammetry and LiDAR which take an unmanned aerial vehicle as a flight platform are the most efficient means for acquiring the original data of the irregular triangulation network, and the irregular triangulation network model can be generated by using ContextCapture image processing software or Terrasolide point cloud processing software.

Step 2: preparation of line configuration files and profile mileage files

The software developed by the invention provides two line calculation methods, one is an intersection point method with definite geometric significance, and the other is a line element method which is a building block method utilizing tangent and circle radius to calculate. The accuracy of the line element method is lower than that of the intersection point method, the error can reach mm level, when the curve elements exist, the intersection point method can be adopted, otherwise, the line element method can be utilized.

Before data processing, an intersection normal route configuration file or a line element normal route configuration file needs to be prepared.

The section mileage file records the mileage and the left and right ranges of the cross section to be automatically extracted, and the software developed by the invention can extract the sections one by one according to the mileage in the file.

And 3, step 3: importing irregular triangulation network model

In ArcGIS software, the irregular triangulation network model is treated as a MultiPath data. The importing process is divided into two steps, firstly, a MultiPath element class is newly built, a coordinate system of the MultiPath element class is set, and then the irregular triangulation network model is imported into the element class; and finally, creating a layer by using the element class and adding the layer to a three-dimensional map window for displaying.

And 4, step 4: extraction section

Firstly, ensuring that an irregular triangulation network graph layer is in a visible state, then reading in a route configuration file and a section mileage file, and sequentially traversing each mileage by software to calculate the coordinate, the tangent and the cross section direction line of the mileage. The cross section extraction process of one mileage is as follows:

(1) and judging whether the mileage is in the configured interval according to the line configuration file, recording an error log if the mileage exceeds the configured interval, and continuously extracting the section of the next mileage.

(2) If the coordinates of the mileage can be calculated, the tangent and cross section lines thereof continue to be calculated according to the profile, see fig. 3.

(3) On the cross section line, according to the left and right ranges and sampling intervals of the mileage section, the plane coordinates of the sampling points are calculated from the mileage points on the line to the left and right respectively, then the elevations of the sampling points are calculated and stored by an elevation interpolation method provided by ArcGIS Object according to the plane coordinates of the sampling points, and fig. 4 shows the sampling on the cross section line with 1 meter as a fixed interval.

And (4) repeating the steps (1) to (3) until cross section sampling and elevation calculation of all the mileage are completed.

And 5, step 5: deriving profile data

And (4) exporting cross section data in a text form, wherein the file contains the coordinates and the elevation of the sampling point of each mileage.

And 6, step 6: drawing a section curve chart

Reading in the section data exported in the step 5, creating a multi-segment line graph layer and a text graph layer, drawing curves and coordinate axes in the multi-segment line graph layer, and adding characters in the text graph layer.

The invention is not limited to the examples, and any equivalent changes to the technical solution of the invention by a person skilled in the art after reading the description of the invention are covered by the claims of the invention.