CN114283070B - Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud - Google Patents

Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud Download PDF

Info

Publication number
CN114283070B
CN114283070B CN202210213772.8A CN202210213772A CN114283070B CN 114283070 B CN114283070 B CN 114283070B CN 202210213772 A CN202210213772 A CN 202210213772A CN 114283070 B CN114283070 B CN 114283070B
Authority
CN
China
Prior art keywords
points
section
unmanned aerial
aerial vehicle
grid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202210213772.8A
Other languages
Chinese (zh)
Other versions
CN114283070A (en
Inventor
王广帅
邓继伟
马帅
高文峰
张冠军
赵海
兰树增
聂虎啸
王凯
张英杰
张文腾
岳亮
葛玉辉
高帅
赵梦杰
王建强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China Railway Design Corp
Original Assignee
China Railway Design Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China Railway Design Corp filed Critical China Railway Design Corp
Priority to CN202210213772.8A priority Critical patent/CN114283070B/en
Publication of CN114283070A publication Critical patent/CN114283070A/en
Application granted granted Critical
Publication of CN114283070B publication Critical patent/CN114283070B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

The invention discloses a method for manufacturing a terrain section by fusing unmanned aerial vehicle image and laser point cloud, which comprises the steps of obtaining unmanned aerial vehicle image and laser point cloud data; generating a digital elevation model, and performing orthorectification on the unmanned aerial vehicle image; constructing a section line with a ground object attribute label; extracting skeleton features and minutiae; combining the section lines with the ground feature attribute labels, the skeleton characteristics and the minutiae to generate a refined sparse terrain section result and the like. The laser point cloud and the unmanned aerial vehicle image are jointly utilized to manufacture the ground line, so that the defect of a single data source is effectively overcome. The method is suitable for high-precision section line manufacturing in complex areas, and can also obtain attribute point information of ground objects such as roads, houses and the like, so that various requirements of engineering investigation and topographic mapping are met.

Description

Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud
Technical Field
The invention relates to the technical field of unmanned aerial vehicle surveying and mapping, in particular to a method for manufacturing a terrain cross section by fusing unmanned aerial vehicle images and laser point clouds.
Background
The terrain section is very important terrain characteristic information, can reflect the elevation fluctuation condition of a local area in a certain plane line direction, and can also vividly display the terrain type and the characteristics of the area. Therefore, the topographic fracture surface is widely applied to the fields of engineering investigation and construction of railways, highways and the like, homeland surveying and mapping and the like. The traditional method for acquiring the terrain section is that an operator utilizes instruments such as a total station, a GPS/RTK and the like to acquire the coordinates of a terrain point in a target area, and then the operator calculates and draws a section vector diagram. However, in actual projects, due to the complex topographic environment of the measuring area (such as mountainous areas, canyons and dense forests), sometimes the operators cannot reach the point to be measured, and the section measuring accuracy cannot be guaranteed. Moreover, the manual measurement mode has low working efficiency and high labor cost, and can not meet the requirements of current engineering construction and topographic mapping on section production gradually.
With the development of software and hardware equipment, unmanned aerial vehicles have gradually become an important survey and drawing remote sensing data acquisition means. Compared with the traditional large-airplane aerial photography, the unmanned aerial vehicle has the advantages of low cost, flexibility and the like, and plays an increasingly important role in urban modeling and engineering investigation design. The digital image sensor is carried by the unmanned aerial vehicle platform, and high-resolution image data can be obtained. The real-scene three-dimensional model obtained by three-dimensional reconstruction based on the image can be used for section measurement. Compared with manual measurement, the method has the advantages that the working efficiency is greatly improved, and the working cost is controlled. However, the problem is that the visible light image cannot observe the ground of the area with more covering objects, and the accurate terrain profile line cannot be obtained by utilizing a real-scene three-dimensional model for the vegetation dense area. The airborne laser radar can effectively solve the problem of topographic survey of vegetation coverage areas by virtue of the characteristic of strong penetrating power, so that the airborne laser radar is widely applied to the field of surveying and mapping. However, engineering investigation tasks such as railways and highways generally require to obtain accurate positions of ground objects such as roads and houses on sections, and laser radars can only obtain three-dimensional coordinates of the ground and cannot obtain spectrum and texture information of the ground objects, so that the attributes of the ground objects such as the roads cannot be directly interpreted from point clouds. In summary, the images of the unmanned aerial vehicle and the laser point clouds can be used for manufacturing the terrain cross section, but the images and the laser point clouds have defects, and a terrain cross section measuring technical method suitable for various conditions cannot be formed by singly depending on a certain technical means. The current unmanned aerial vehicle platform can carry on laser radar and visible light image sensor simultaneously, and how fully jointly use the spectrum texture information that ground three-dimensional coordinate that laser radar measurement obtained and image provided, it is still a difficult point to obtain the topography section that satisfies the survey and drawing demand.
Disclosure of Invention
Therefore, the invention aims to provide a method for manufacturing a topographic cross section by fusing an unmanned aerial vehicle image and a laser point cloud, wherein the laser point cloud and the unmanned aerial vehicle image are jointly utilized to manufacture a ground line, so that the defect of a single data source is effectively overcome. The method is suitable for high-precision section line production of complex areas (such as vegetation coverage areas), and can also obtain attribute point information of ground objects such as roads, houses and the like, thereby meeting various requirements of engineering investigation and topographic mapping.
In order to achieve the purpose, the invention discloses a method for manufacturing a terrain cross section by fusing an unmanned aerial vehicle image and a laser point cloud, which comprises the following steps:
s1, acquiring unmanned aerial vehicle images and laser point cloud data;
s2, extracting ground point data from the obtained laser point cloud data to generate a digital elevation model, and performing orthorectification on the unmanned aerial vehicle image based on the digital elevation model;
s3, constructing an irregular triangular net by using the extracted ground point data, calculating to obtain a section line and a position of the section line on an orthoimage by using the irregular triangular net according to input section plane position information, and adding a ground attribute label to the section line by combining image texture information in the unmanned aerial vehicle image to finally obtain the section line with the ground attribute label;
s4, extracting key points from the section line, and obtaining the linear skeleton characteristics of the section by using the key points; calculating the detail points of local characteristic change by adopting a local detection method;
and S5, combining the section lines with the ground feature attribute labels, the skeleton characteristics and the minutiae to generate a refined sparse terrain section result.
Further preferably, in S2, when the ground point data is extracted from the acquired laser point cloud data to generate the digital elevation model, the method includes the following steps:
s201, performing gross error point detection on the acquired laser point cloud, and removing gross error points according to a detection result;
s202, filtering the laser point cloud after the rough difference points are removed, and obtaining ground points and non-ground points by adopting a filtering algorithm (including but not limited to a semi-global filtering algorithm, a progressive triangulation network filtering algorithm and a morphological filtering algorithm); and constructing a triangulation network by using the ground points, and performing interpolation to obtain a digital elevation model.
Further preferably, in S201, the following method is adopted to perform rough point detection on the acquired laser point cloud:
dividing the three-dimensional grid into a plurality of cuboids according to the size of a preset grid for the acquired laser point cloud data, and respectively counting the number of laser points falling into each cuboid grid; when the number of laser points in a certain cuboid grid is less than a preset threshold value, the cuboid grid is marked as a suspected rough difference grid, the number of the laser points of 26 neighborhood grids of the suspected rough difference grid in a three-dimensional space is counted, if at least one grid exists in the 26 neighborhood grids, the grid is a non-suspected grid, the grid is a normal grid, and otherwise, the points in the cuboid grid are judged to be rough difference points.
Further preferably, in S2, the method for performing orthorectification on the unmanned aerial vehicle image based on the digital elevation model includes:
projecting four vertexes of the acquired unmanned aerial vehicle image onto the digital elevation model to obtain the coverage range of the unmanned aerial vehicle image on the ground;
dividing the coverage area into two-dimensional grids along X and Y directions, and back-projecting a central point to the unmanned aerial vehicle image by utilizing a collinear condition equation for each grid to obtain an accurate position point of the central point on the unmanned aerial vehicle image;
and then calculating the gray value of the grid where the precise position point is located by utilizing the gray value of the neighborhood pixel of the precise position point and adopting a bilinear interpolation method, and by analogy, calculating the gray values of all grid points to finish the correction of the orthographic image of the unmanned aerial vehicle.
Further preferably, in S3, an irregular triangulation network is constructed using the extracted ground point data, and a section line is calculated using the irregular triangulation network according to the input section plane position information, including the steps of:
the input section plane position information comprises plane coordinates of a plurality of section nodes; according to the plane coordinates of the section nodes, the section is intercepted on the irregular triangular net to obtain an original section line L;
calculating section line
Figure 566624DEST_PATH_IMAGE002
Intersection with triangle side in triangulation network
Figure 393766DEST_PATH_IMAGE004
Plane coordinates, calculating the intersection point by interpolation according to the elevation values of two end points of the intersecting triangle side
Figure 397494DEST_PATH_IMAGE004
The elevation value of (a);
and performing the elevation interpolation calculation on all the triangles to obtain the elevation values of all the section points, thereby forming a complete section line.
Further preferably, in S3, when an irregular triangulation network is constructed using the extracted ground point data, and the position of the cross-sectional line on the ortho-image is calculated using the irregular triangulation network based on the input cross-sectional plane position information, the following method is employed:
setting the node coordinates of the section line
Figure 651889DEST_PATH_IMAGE005
The affine transformation parameters of the orthographic image of the unmanned aerial vehicle are
Figure 842699DEST_PATH_IMAGE006
Then line node is broken
Figure 598166DEST_PATH_IMAGE007
Coordinates on an orthoimage of an unmanned aerial vehicle
Figure 66187DEST_PATH_IMAGE008
The calculation formula is as follows:
Figure 881696DEST_PATH_IMAGE009
in the formula (I), the compound is shown in the specification,
Figure 559802DEST_PATH_IMAGE010
further preferably, in S3, the feature attribute labels include house, road, scarp, river.
Further preferably, in S4, extracting key points from the cross section line, and obtaining the skeleton feature of the cross section line by using the key points, the method includes the following steps:
obtaining key points of a section line as initial skeleton points, wherein the key points comprise end points, highest points and lowest points;
connecting lines of two adjacent framework points to serve as a processing unit, and sequentially judging whether the interior of each processing unit contains other framework points;
and acquiring a vector set of all the skeleton points as the skeleton characteristics of the section line shape.
Further preferably, the method for sequentially determining whether each processing unit includes other skeleton points includes the following steps:
calculating any section node in each processing unit
Figure 728747DEST_PATH_IMAGE011
Connecting lines to two skeleton points
Figure 441488DEST_PATH_IMAGE012
Perpendicular distance therebetween
Figure 37685DEST_PATH_IMAGE013
Distance from plumb
Figure 203087DEST_PATH_IMAGE014
Selecting
Figure 300356DEST_PATH_IMAGE013
And
Figure 742970DEST_PATH_IMAGE014
is larger value as
Figure 900282DEST_PATH_IMAGE011
A characteristic saliency value of;
calculating the characteristic significant values of all the section points to obtain the node with the maximum characteristic significant value
Figure 428346DEST_PATH_IMAGE015
If a node
Figure 63727DEST_PATH_IMAGE015
Is greater than a first preset threshold
Figure 626427DEST_PATH_IMAGE016
Then consider the node
Figure 689061DEST_PATH_IMAGE015
Adding the skeleton points into a skeleton point queue, otherwise, considering the skeleton points as skeleton points
Figure 563476DEST_PATH_IMAGE012
The interior does not contain skeleton points.
More preferably, in S4, when calculating the minutiae of the local characteristic change by the local detection method, three adjacent nodes are sequentially extracted from the end point of the cross-sectional line
Figure 143493DEST_PATH_IMAGE018
Figure 419753DEST_PATH_IMAGE020
And
Figure 918868DEST_PATH_IMAGE022
calculating the intermediate point
Figure 421524DEST_PATH_IMAGE020
To
Figure 398708DEST_PATH_IMAGE018
And
Figure 670420DEST_PATH_IMAGE022
vertical distance of connecting line and plumb distance
Figure 74857DEST_PATH_IMAGE024
And
Figure 189443DEST_PATH_IMAGE026
get it
Figure 580104DEST_PATH_IMAGE024
And
Figure 96536DEST_PATH_IMAGE026
the larger value of the sum as
Figure 671874DEST_PATH_IMAGE020
Local saliency value of
Figure 149123DEST_PATH_IMAGE028
If local significance is present
Figure 733688DEST_PATH_IMAGE028
Greater than a second predetermined threshold
Figure 714414DEST_PATH_IMAGE030
Then it is considered as
Figure 460653DEST_PATH_IMAGE020
Is a minutia point; and sequentially judging whether each section node is a detail point.
The application discloses a fuse topography section preparation method of unmanned aerial vehicle image and laser point cloud compares in prior art, has following advantage at least:
1. the application discloses a method for manufacturing a terrain section by fusing an unmanned aerial vehicle image and a laser point cloud, which is used for manufacturing a ground line by jointly utilizing the laser point cloud and the unmanned aerial vehicle image, and effectively avoids the defect of a single data source. The method is suitable for high-precision section line production of complex areas (such as vegetation coverage areas), and can also obtain attribute point information of ground objects such as roads, houses and the like, thereby meeting various requirements of engineering investigation and topographic mapping.
2. The application discloses a method for manufacturing a terrain section by fusing unmanned aerial vehicle images and laser point clouds provides an effective method for refining and thinning nodes of the profile line, can obtain skeleton points and key points of local feature details which reflect terrain features, and solves the problems that traditional section achievement points are more in number and large in redundancy.
3. The application discloses a method for manufacturing a terrain section by fusing unmanned aerial vehicle image and laser point cloud, when guaranteeing the quality of a terrain section measuring result, greatly reduces field work load in the traditional terrain measuring process, improves operation efficiency and safety, reduces production operation economic cost, and has strong practical application and popularization value.
Drawings
Fig. 1 is a schematic flow chart of the method for manufacturing a topographic cross section by fusing an unmanned aerial vehicle image and a laser point cloud.
Fig. 2 is a schematic diagram of the least square optimization of the center line of the top surface of the steel rail in the method for manufacturing the topographic cross section by fusing the unmanned aerial vehicle image and the laser point cloud provided by the invention.
Fig. 3 is a schematic diagram of track straight/curve judgment.
Detailed Description
The invention is described in further detail below with reference to the figures and the detailed description.
As shown in fig. 1, an embodiment of the invention provides a method for manufacturing a topographic cross section by fusing an image of an unmanned aerial vehicle and a laser point cloud, which includes the following steps:
s1, acquiring unmanned aerial vehicle images and laser point cloud data; it should be noted that the method also includes accurate external orientation elements of the image and parameters in the camera;
s2, extracting ground point data from the obtained laser point cloud data to generate a digital elevation model, and performing orthorectification on the unmanned aerial vehicle image based on the digital elevation model;
s3, constructing an irregular triangular net by using the extracted ground point data, calculating to obtain a section line and a position of the section line on an orthoimage by using the irregular triangular net according to input section plane position information, and adding a ground attribute label to the section line by combining image texture information in the unmanned aerial vehicle image to finally obtain the section line with the ground attribute label;
s4, extracting key points from the section line, and obtaining the linear skeleton characteristics of the section by using the key points; calculating the detail points of local characteristic change by adopting a local detection method;
and S5, combining the section lines with the ground feature attribute labels, the skeleton characteristics and the minutiae to generate a refined sparse terrain section result.
In S2, when extracting ground point data from the acquired laser point cloud data and generating a digital elevation model, first removing low points and noise points from the laser point cloud by using a grid detection method, then performing point cloud filtering and generating a digital elevation model using the ground points, specifically including the following steps:
s201, performing gross error point detection on the acquired laser point cloud, and removing gross error points according to detection results;
s202, filtering the laser point cloud after the rough difference points are removed, and obtaining ground points and non-ground points by adopting a filtering algorithm (specifically, a semi-global filtering algorithm, a progressive triangulation network filtering algorithm or a morphological filtering algorithm); and constructing a triangulation network by using the ground points, and performing interpolation to obtain a digital elevation model.
In S201, the following method is adopted to perform rough point detection on the acquired laser point cloud:
dividing the three-dimensional grid into a plurality of cuboids according to the acquired laser point cloud data by the preset grid size, and respectively counting the number of laser points, namely LiDAR points, falling into each cuboid grid; as shown in FIG. 2, if the number of points in a grid is less than a certain threshold
Figure 284252DEST_PATH_IMAGE031
If so, the point in the grid is considered as a suspected gross error point, and the grid is a suspected gross error grid. For each suspected coarse difference grid
Figure DEST_PATH_IMAGE032
Counting the number of LiDAR points of 26 neighborhood grids in the three-dimensional space, and if at least one grid in the 26 neighborhood grids is a non-suspected grid, determining that the grid is a non-suspected grid
Figure 813454DEST_PATH_IMAGE032
Is a normal grid, otherwise, the grid is judged
Figure 914265DEST_PATH_IMAGE032
The inner points are all coarse difference points.
In S2, performing orthorectification on the unmanned aerial vehicle image based on the digital elevation model, using the following method:
projecting four vertexes of the acquired unmanned aerial vehicle image onto the digital elevation model to obtain the coverage range of the unmanned aerial vehicle image on the ground;
dividing the coverage area into two-dimensional grids along X and Y directions, and back-projecting a central point to the unmanned aerial vehicle image by utilizing a collinear condition equation for each grid to obtain an accurate position point of the central point on the unmanned aerial vehicle image;
and then calculating the gray value of the grid where the accurate position point is located by utilizing the gray value of the neighborhood pixels of the accurate position point and adopting a bilinear interpolation method, and so on to obtain the gray values of all grid points and finish the correction of the orthoimage of the unmanned aerial vehicle.
In S3, an irregular triangulation network is constructed using the extracted ground point data, and a section line is calculated using the irregular triangulation network according to the input section plane position information, including the steps of:
the input section plane position information comprises plane coordinates of a plurality of section nodes; according to the plane coordinates of the section nodes, the section is intercepted on the irregular triangular net to obtain an original section line L;
calculating section line
Figure 831405DEST_PATH_IMAGE002
Intersection with triangle side in triangulation network
Figure 407880DEST_PATH_IMAGE004
Plane coordinates, calculating the intersection point by interpolation according to the elevation values of two end points of the intersecting triangle side
Figure 944035DEST_PATH_IMAGE004
The elevation value of (a);
and performing the elevation interpolation calculation on all the triangles to obtain the elevation values of all the section points to form a complete section line.
Further preferably, in S3, when an irregular triangulation network is constructed using the extracted ground point data, and the position of the cross-sectional line on the ortho-image is calculated using the irregular triangulation network based on the input cross-sectional plane position information, the following method is employed:
setting the node coordinates of the section line
Figure 23986DEST_PATH_IMAGE033
The affine transformation parameters of the orthographic image of the unmanned aerial vehicle are
Figure DEST_PATH_IMAGE034
Then line node is broken
Figure 784132DEST_PATH_IMAGE035
Coordinates on an orthoimage of an unmanned aerial vehicle
Figure DEST_PATH_IMAGE036
The calculation formula is as follows:
Figure 723269DEST_PATH_IMAGE037
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE038
according to calculation
Figure 453328DEST_PATH_IMAGE039
Image coordinates and, the coordinatesThe image texture at the point can judge the node
Figure 263152DEST_PATH_IMAGE035
The feature attribute labels include houses, roads, scarves, rivers, and the like, thereby giving attribute information to the relevant nodes. And obtaining a complete topographic section line with the information of the semantic attributes of the terrain.
Further preferably, in S4, extracting key points in the cross-sectional line, and obtaining the skeleton feature of the cross-sectional line shape by using the key points, the method includes:
obtaining key points of a section line as initial skeleton points, wherein the key points comprise end points, highest points and lowest points;
connecting lines of two adjacent framework points to serve as a processing unit, and sequentially judging whether the interior of each processing unit contains other framework points;
and acquiring a vector set of all the skeleton points as the skeleton characteristics of the section line shape.
As shown in fig. 3, it is further preferable that the method sequentially determines whether or not each of the processing units includes another skeleton point, including the steps of:
calculating any section node in each processing unit
Figure 53253DEST_PATH_IMAGE011
Connecting lines to two skeleton points
Figure 807583DEST_PATH_IMAGE012
Perpendicular distance therebetween
Figure 216698DEST_PATH_IMAGE013
Distance from plumb
Figure 271242DEST_PATH_IMAGE014
Selecting
Figure 842032DEST_PATH_IMAGE013
And
Figure 349237DEST_PATH_IMAGE014
is larger value as
Figure 296464DEST_PATH_IMAGE011
A characteristic saliency value of;
calculating the characteristic significant values of all the section points to obtain the node with the maximum characteristic significant value
Figure 939935DEST_PATH_IMAGE015
If a node
Figure 71839DEST_PATH_IMAGE015
Is greater than a first preset threshold
Figure 676127DEST_PATH_IMAGE016
Then consider the node
Figure 551679DEST_PATH_IMAGE015
Adding the skeleton points into a skeleton point queue, otherwise, considering the skeleton points as skeleton points
Figure 315236DEST_PATH_IMAGE012
The interior does not contain skeleton points.
More preferably, in S4, when calculating the minutiae of the local characteristic change by the local detection method, three adjacent nodes are sequentially extracted from the end point of the cross-sectional line
Figure 227828DEST_PATH_IMAGE018
Figure 709625DEST_PATH_IMAGE020
And
Figure 998655DEST_PATH_IMAGE022
calculating the intermediate point
Figure 882297DEST_PATH_IMAGE020
To
Figure 824845DEST_PATH_IMAGE018
And
Figure 669305DEST_PATH_IMAGE022
vertical distance of connecting line and plumb distance
Figure 621080DEST_PATH_IMAGE024
And
Figure 234595DEST_PATH_IMAGE026
get it
Figure 613624DEST_PATH_IMAGE024
And
Figure 70013DEST_PATH_IMAGE026
and, taking the larger value of the sum as
Figure 689127DEST_PATH_IMAGE020
Local saliency value of
Figure 547362DEST_PATH_IMAGE028
If local significance is present
Figure 972658DEST_PATH_IMAGE028
Greater than a second predetermined threshold
Figure 650764DEST_PATH_IMAGE030
Then it is considered as
Figure 944342DEST_PATH_IMAGE020
Is a minutia point; and sequentially judging whether each section node is a detail point.
And finally, combining the ground feature attribute points, the skeleton points and the fine nodes to obtain a result of the refined sparse terrain section points, and outputting and storing the result.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (10)

1. A method for manufacturing a terrain section by fusing unmanned aerial vehicle images and laser point clouds is characterized by comprising the following steps:
s1, acquiring unmanned aerial vehicle images and laser point cloud data;
s2, extracting ground point data from the obtained laser point cloud data to generate a digital elevation model, and performing orthorectification on the unmanned aerial vehicle image based on the digital elevation model;
s3, constructing an irregular triangular net by using the extracted ground point data, calculating to obtain a section line and a position of the section line on an orthoimage by using the irregular triangular net according to input section plane position information, and adding a ground attribute label to the section line by combining image texture information in the unmanned aerial vehicle image to finally obtain the section line with the ground attribute label;
s4, extracting key points from the section line, and obtaining the linear skeleton characteristics of the section by using the key points; calculating the detail points of local characteristic change by adopting a local detection method;
and S5, combining the section lines with the ground feature attribute labels, the skeleton characteristics and the minutiae to generate a refined sparse terrain section result.
2. The method for manufacturing the terrain section fusing the unmanned aerial vehicle image and the laser point cloud as claimed in claim 1, wherein in S2, when extracting ground point data from the obtained laser point cloud data and generating the digital elevation model, the method comprises the following steps:
s201, performing gross error point detection on the acquired laser point cloud, and removing gross error points according to detection results;
s202, filtering the laser point cloud with the coarse difference points removed, and obtaining ground points and non-ground points by adopting a filtering algorithm; and constructing a triangulation network by using the ground points, and performing interpolation to obtain a digital elevation model.
3. The method for manufacturing the terrain cross section fusing the unmanned aerial vehicle image and the laser point cloud according to claim 2, wherein in S201, the laser point cloud obtained is subjected to gross error point detection by adopting the following method:
dividing the three-dimensional grid into a plurality of cuboids according to the size of a preset grid for the acquired laser point cloud data, and respectively counting the number of laser points falling into each cuboid grid; when the number of laser points in a certain cuboid grid is less than a preset threshold value, the cuboid grid is marked as a suspected rough difference grid, the number of the laser points of 26 neighborhood grids of the suspected rough difference grid in a three-dimensional space is counted, if at least one grid exists in the 26 neighborhood grids, the grid is a non-suspected grid, the grid is a normal grid, and otherwise, the points in the cuboid grid are judged to be rough difference points.
4. The method for manufacturing a terrain profile fusing an unmanned aerial vehicle image and a laser point cloud according to claim 1, wherein in S2, the unmanned aerial vehicle image is subjected to orthorectification based on a digital elevation model by adopting the following method:
projecting four vertexes of the acquired unmanned aerial vehicle image onto the digital elevation model to obtain the coverage range of the unmanned aerial vehicle image on the ground;
dividing the coverage area into two-dimensional grids along X and Y directions, and back-projecting a central point to the unmanned aerial vehicle image by utilizing a collinear condition equation for each grid to obtain an accurate position point of the central point on the unmanned aerial vehicle image;
and calculating the gray value of the grid where the accurate position point is located by utilizing the gray value of the neighborhood pixels of the accurate position point and adopting a bilinear interpolation method, and by analogy, calculating the gray values of all grid points to finish the correction of the orthographic image of the unmanned aerial vehicle.
5. The method for creating a topographic cross-section fusing an unmanned aerial vehicle image and a laser point cloud according to claim 1, wherein an irregular triangulation network is constructed in S3 using the extracted ground point data, and a cross-sectional line is calculated using the irregular triangulation network according to input cross-sectional plane position information, comprising:
the input section plane position information comprises plane coordinates of a plurality of section nodes; according to the plane coordinates of the section nodes, the section is intercepted on the irregular triangular net to obtain an original section line L;
calculating section line
Figure 196291DEST_PATH_IMAGE001
Intersection with triangle side in triangulation network
Figure 981758DEST_PATH_IMAGE002
Plane coordinates, calculating the intersection point by interpolation according to the elevation values of two end points of the intersecting triangle side
Figure 435873DEST_PATH_IMAGE002
The elevation value of (a);
and performing the elevation interpolation calculation on all the triangles to obtain the elevation values of all the section points to form a complete section line.
6. The method of claim 1, wherein in step S3, an irregular triangulation network is constructed using the extracted ground point data, and the position of the cross-sectional line on the orthographic image is calculated using the irregular triangulation network based on the input cross-sectional plane position information, by using the following method:
setting the node coordinates of the section line
Figure 339107DEST_PATH_IMAGE003
The affine transformation parameters of the orthoimage of the unmanned aerial vehicle are
Figure 878672DEST_PATH_IMAGE004
Then line node is broken
Figure 276287DEST_PATH_IMAGE005
Coordinates on an orthoimage of an unmanned aerial vehicle
Figure 381646DEST_PATH_IMAGE006
The calculation formula is as follows:
Figure 331148DEST_PATH_IMAGE007
in the formula (I), the compound is shown in the specification,
Figure 217064DEST_PATH_IMAGE008
7. the method of claim 1, wherein in step S3, the ground feature labels include house, road, scarp, river.
8. The method for manufacturing the terrain cross section by fusing the unmanned aerial vehicle image and the laser point cloud according to claim 1, wherein in S4, key points are extracted from a cross section line, and a skeleton feature of a cross section line shape is obtained by using the key points, and the method comprises the following steps:
obtaining key points of a section line as initial skeleton points, wherein the key points comprise end points, highest points and lowest points;
connecting lines of two adjacent framework points to serve as a processing unit, and sequentially judging whether the interior of each processing unit contains other framework points;
and acquiring a vector set of all the skeleton points as the skeleton characteristics of the section line shape.
9. The method for manufacturing the terrain cross section fusing the unmanned aerial vehicle image and the laser point cloud according to claim 8, wherein when it is sequentially judged whether the interior of each processing unit contains other skeleton points, the method comprises the following steps:
computing any of the interior of each processing unitSection node
Figure 543003DEST_PATH_IMAGE009
Connecting lines to two skeleton points
Figure 581497DEST_PATH_IMAGE010
Perpendicular distance therebetween
Figure 701900DEST_PATH_IMAGE011
Distance from plumb
Figure 543954DEST_PATH_IMAGE012
Selecting
Figure 283371DEST_PATH_IMAGE011
And
Figure 97743DEST_PATH_IMAGE012
is larger value as
Figure 654627DEST_PATH_IMAGE009
A characteristic saliency value of;
calculating the characteristic significant values of all the section points to obtain the node with the maximum characteristic significant value
Figure 515135DEST_PATH_IMAGE013
If a node
Figure 917298DEST_PATH_IMAGE013
Is greater than a first preset threshold
Figure 664805DEST_PATH_IMAGE014
Then consider the node
Figure 392590DEST_PATH_IMAGE013
Adding the skeleton points into a skeleton point queue, otherwise, considering the skeleton points as skeleton points
Figure 412498DEST_PATH_IMAGE010
The interior does not contain skeleton points.
10. The method of claim 9, wherein in step S4, when calculating the detail points of the local feature changes by using a local detection method, three adjacent nodes are sequentially extracted from the end point of the cross-sectional line
Figure 742985DEST_PATH_IMAGE015
Figure 469633DEST_PATH_IMAGE016
And
Figure 243685DEST_PATH_IMAGE017
calculating the intermediate point
Figure 688573DEST_PATH_IMAGE016
To
Figure 494855DEST_PATH_IMAGE015
And
Figure 731801DEST_PATH_IMAGE017
vertical distance of connecting line and plumb distance
Figure 270230DEST_PATH_IMAGE018
And
Figure 343359DEST_PATH_IMAGE019
get it
Figure 891015DEST_PATH_IMAGE018
And
Figure 654572DEST_PATH_IMAGE019
is larger value as
Figure 754115DEST_PATH_IMAGE016
Local saliency value of
Figure 439174DEST_PATH_IMAGE020
If local significance is present
Figure 400308DEST_PATH_IMAGE020
Greater than a second predetermined threshold
Figure 221634DEST_PATH_IMAGE021
Then it is considered as
Figure 429761DEST_PATH_IMAGE016
Is a minutia point; and sequentially judging whether each section node is a detail point.
CN202210213772.8A 2022-03-07 2022-03-07 Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud Active CN114283070B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210213772.8A CN114283070B (en) 2022-03-07 2022-03-07 Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210213772.8A CN114283070B (en) 2022-03-07 2022-03-07 Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud

Publications (2)

Publication Number Publication Date
CN114283070A CN114283070A (en) 2022-04-05
CN114283070B true CN114283070B (en) 2022-05-03

Family

ID=80882272

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210213772.8A Active CN114283070B (en) 2022-03-07 2022-03-07 Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud

Country Status (1)

Country Link
CN (1) CN114283070B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115048838B (en) * 2022-06-14 2024-04-09 湖南大学 Human body feature-based rapid human skeleton finite element model modeling method
CN115546266B (en) * 2022-11-24 2023-03-17 中国铁路设计集团有限公司 Multi-strip airborne laser point cloud registration method based on local normal correlation

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101154295A (en) * 2006-09-28 2008-04-02 长江航道规划设计研究院 Three-dimensional simulation electronic chart of navigation channel
CN102682479A (en) * 2012-04-13 2012-09-19 国家基础地理信息中心 Method for generating three-dimensional terrain feature points on irregular triangulation network
CN107092020A (en) * 2017-04-19 2017-08-25 北京大学 Merge the surface evenness monitoring method of unmanned plane LiDAR and high score image
CN110046563A (en) * 2019-04-02 2019-07-23 中国能源建设集团江苏省电力设计院有限公司 A kind of transmission line of electricity measuring height of section modification method based on unmanned plane point cloud
CN110390255A (en) * 2019-05-29 2019-10-29 中国铁路设计集团有限公司 High-speed rail environmental change monitoring method based on various dimensions feature extraction
CN111429498A (en) * 2020-03-26 2020-07-17 中国铁路设计集团有限公司 Railway business line three-dimensional center line manufacturing method based on point cloud and image fusion technology
CN111597605A (en) * 2020-04-02 2020-08-28 中国国家铁路集团有限公司 Railway dynamic simulation cockpit system
CN112562079A (en) * 2020-12-22 2021-03-26 中铁第四勘察设计院集团有限公司 Method, device and equipment for thinning topographic section data

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101154295A (en) * 2006-09-28 2008-04-02 长江航道规划设计研究院 Three-dimensional simulation electronic chart of navigation channel
CN102682479A (en) * 2012-04-13 2012-09-19 国家基础地理信息中心 Method for generating three-dimensional terrain feature points on irregular triangulation network
CN107092020A (en) * 2017-04-19 2017-08-25 北京大学 Merge the surface evenness monitoring method of unmanned plane LiDAR and high score image
CN110046563A (en) * 2019-04-02 2019-07-23 中国能源建设集团江苏省电力设计院有限公司 A kind of transmission line of electricity measuring height of section modification method based on unmanned plane point cloud
CN110390255A (en) * 2019-05-29 2019-10-29 中国铁路设计集团有限公司 High-speed rail environmental change monitoring method based on various dimensions feature extraction
CN111429498A (en) * 2020-03-26 2020-07-17 中国铁路设计集团有限公司 Railway business line three-dimensional center line manufacturing method based on point cloud and image fusion technology
CN111597605A (en) * 2020-04-02 2020-08-28 中国国家铁路集团有限公司 Railway dynamic simulation cockpit system
CN112562079A (en) * 2020-12-22 2021-03-26 中铁第四勘察设计院集团有限公司 Method, device and equipment for thinning topographic section data

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
"Road_Profile_Estimation_Using_a_3D_Sensor_and_Inte";Tao Ni等;《sensors》;20200731;第1-17页 *
"无人机激光点云和多光谱数据的融合技术研究";陈杰;《中国新技术新产品》;20210731;第5-7页 *
"无人机航摄在铁路工程中的应用";邓继伟;《铁道勘察》;20200430;第23-27页 *
"无人机铁路综合巡线应用研究";赵海 等;《科技成果》;20200728;第1-5页 *
"海量低空机载LiDAR点云的地形断面快速生成算法";周建红 等;《测绘科学技术学报》;20180723;第170-174页 *

Also Published As

Publication number Publication date
CN114283070A (en) 2022-04-05

Similar Documents

Publication Publication Date Title
CN102506824B (en) Method for generating digital orthophoto map (DOM) by urban low altitude unmanned aerial vehicle
CN111597666B (en) Method for applying BIM to transformer substation construction process
US7944547B2 (en) Method and system of generating 3D images with airborne oblique/vertical imagery, GPS/IMU data, and LIDAR elevation data
CN114283070B (en) Method for manufacturing terrain section by fusing unmanned aerial vehicle image and laser point cloud
CN113607135B (en) Unmanned aerial vehicle inclination photogrammetry method for road and bridge construction field
CN105783878A (en) Small unmanned aerial vehicle remote sensing-based slope deformation detection and calculation method
CN104952107A (en) Three-dimensional bridge reconstruction method based on vehicle-mounted LiDAR point cloud data
CN111105496A (en) High-precision DEM construction method based on airborne laser radar point cloud data
CN112100715A (en) Three-dimensional oblique photography technology-based earthwork optimization method and system
CN113916130B (en) Building position measuring method based on least square method
CN111667569B (en) Three-dimensional live-action soil visual accurate measurement and calculation method based on Rhino and Grasshopper
CN114859374B (en) Newly-built railway cross measurement method based on unmanned aerial vehicle laser point cloud and image fusion
CN109146990B (en) Building outline calculation method
CN110889899A (en) Method and device for generating digital earth surface model
Sun et al. Building displacement measurement and analysis based on UAV images
CN110046563B (en) Power transmission line section elevation correction method based on unmanned aerial vehicle point cloud
CN111006645A (en) Unmanned aerial vehicle surveying and mapping method based on motion and structure reconstruction
Mao et al. Precision evaluation and fusion of topographic data based on UAVs and TLS surveys of a loess landslide
Rebelo et al. Building 3D city models: Testing and comparing Laser scanning and low-cost UAV data using FOSS technologies
Ahmad et al. Generation of three dimensional model of building using photogrammetric technique
CN113744393B (en) Multi-level slope landslide change monitoring method
WO2022104251A1 (en) Image analysis for aerial images
CN114004949A (en) Airborne point cloud assisted mobile measurement system arrangement parameter calibration method and system
Song et al. Multi-feature airborne LiDAR strip adjustment method combined with tensor voting algorithm
Chen et al. 3D model construction and accuracy analysis based on UAV tilt photogrammetry

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant