CN110706153B - Tunnel section rapid extraction method based on original point cloud data - Google Patents

Tunnel section rapid extraction method based on original point cloud data Download PDF

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CN110706153B
CN110706153B CN201911276835.9A CN201911276835A CN110706153B CN 110706153 B CN110706153 B CN 110706153B CN 201911276835 A CN201911276835 A CN 201911276835A CN 110706153 B CN110706153 B CN 110706153B
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tunnel
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吴勇生
曾雄鹰
龙兴
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Hunan Lianzhi Technology Co Ltd
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    • G06T3/00Geometric image transformations in the plane of the image
    • G06T3/06Topological mapping of higher dimensional structures onto lower dimensional surfaces
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    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
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    • G01CMEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
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Abstract

The invention provides a tunnel section rapid extraction method based on original point cloud data. The method comprises the following steps: the method comprises the following steps: scanning the acquired tunnel surface original coordinate point cloud data Dr; step two: calculating a slope k at the section S to be extracted, and obtaining sorted point cloud data Ds according to the value of k; step three: crude extraction of point cloud data to obtain point cloud data Dc; step four: carrying out fine extraction on point cloud data to obtain a point set Dp of a section; step five: the extracted cross-section point set Dp is converted to a planar coordinate system. According to the method, a tunnel section design drawing and a flat curve element table and a vertical curve element table of an interval where a tunnel is located are collected; and calculating the central coordinate and normal vector of the section to be extracted, and performing two times of extraction, coarse extraction and fine extraction, wherein 90% of point cloud data can be filtered out in the coarse extraction operation, so that the calculation efficiency is improved, the extracted section coordinate data is finally obtained, and the extracted section coordinate data can be converted into a plane coordinate system as required.

Description

Tunnel section rapid extraction method based on original point cloud data
Technical Field
The invention relates to the technical field of monitoring and measuring of three-dimensional laser scanning tunnels, in particular to a tunnel section rapid extraction method based on original point cloud data.
Background
The monitoring and measuring technology is an important component of tunnel construction, is an important technical means for mastering the surrounding rock dynamics and verifying the rationality of a supporting structure, and is an important basis for determining reasonable supporting time. The importance of monitoring and measuring technology is self-evident, a management unit also invests a large amount of manpower and material resources, however, the monitoring and measuring means have not been developed greatly in the last two decades, mechanical measuring means such as a precise level gauge and a convergence gauge are still used, the efficiency is extremely low, and the measuring result is seriously interfered by human beings. A plurality of defects of the traditional monitoring means are overcome, and the construction unit pays attention to the defects, so that the actual monitoring and measuring work is more and more floated on the surface, and the management unit is very headache.
Therefore, when the three-dimensional laser scanning technology is introduced to the field of monitoring and measuring, the tunnel construction management unit shows great interest. The three-dimensional laser scanning technology is high-efficient, stable and reliable in tunnel monitoring and measuring, and tunnel construction units are conquered gradually.
With the gradual maturity and continuous development of the three-dimensional laser scanning technology, in tunnel deformation monitoring or detection work, the three-dimensional laser scanner is increasingly applied to tunnels and underground engineering due to the advantages that the three-dimensional laser scanner does not need to be in direct contact with a target to be detected, and a large amount of data information can be acquired in a short time. By utilizing three-dimensional laser scanner data post-processing software, according to a fitted tunnel model generated by registration, the deviation between each section of tunnel and the designed model is detected with high precision by comparing with the designed model, and the task requirements in a series of tunnel engineering construction such as tunnel vault settlement, convergence displacement, bias voltage condition, overexcavation and underexcavation, axis deviation, initial support invasion limit, secondary lining thickness primary detection and the like can be accurately obtained.
In the traditional tunnel monitoring and measuring work, the total station and the level gauge are heavy in observation task, small in data quantity and more in error factors, so that the three-dimensional laser scanning technology can play great advantages in the aspects of tunnel monitoring and measuring and the like.
In the application of the three-dimensional laser scanning technology to the tunnel, monitoring and measuring work is generally performed by extracting a section, which is mainly because tunnel monitoring and measuring are always performed by taking the section as a unit. The existing section extraction method mainly comprises the steps of performing surface fitting on tunnel cloud breaking data, and then performing slicing processing according to tunnel route design information to obtain measurement data of each section. The method has the defects that the point cloud data subjected to integral fitting possibly has a local distortion problem, so that the extracted section data cannot truly reflect the actual change condition of the tunnel, and further the measuring significance is lost.
In summary, a method for rapidly extracting a tunnel section based on original point cloud data is urgently needed to solve the problems in the prior art.
Disclosure of Invention
The invention aims to provide a tunnel section rapid extraction method based on original point cloud data, so as to solve the problem of rapid extraction of the tunnel section.
In order to achieve the aim, the invention provides a tunnel section rapid extraction method based on original point cloud data, which comprises the following steps:
the method comprises the following steps: collecting tunnel section design drawing, route flat curve element table and vertical curve element table of the section where the tunnel section design drawing is located, and tunnel surface original coordinate point cloud data obtained by scanning
Figure 549583DEST_PATH_IMAGE001
Step two: calculating a slope k of the section S to be extracted, and sequencing the original coordinate point cloud data Dr along the x-axis or y-axis direction of a coordinate axis according to the value of k to obtain sequenced point cloud data Ds;
step three: roughly extracting point cloud data, namely extracting point cloud data Dc of a coordinate interval where the section S is located from the sorted tunnel original coordinate point cloud data Ds according to the tunnel clearance width L and the slope k;
step four: accurately extracting point cloud data, and calculating a central three-dimensional coordinate O at the section S to be extracted
Figure DEST_PATH_IMAGE003AAAA
And a normal vector n thereof, and calculating a point set Dp of the section to be extracted according to a distance formula from the point to the plane;
step five: the extracted cross-section point set Dp is converted to a planar coordinate system.
Further, the calculation method of the slope k is as follows:
Figure 494405DEST_PATH_IMAGE004
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE006AAAA
is the azimuth angle of the line element starting point coordinate, R is the radius of the circular curve,
Figure 971523DEST_PATH_IMAGE007
to moderate the curve length, s is the calculated cross-section to line elementAnd F is a symbol parameter, and takes 1 when the line element is deviated to the left and takes 1 when the line element is deviated to the right.
Further, the ordering rule of the original coordinate point cloud data Dr in the second step is as follows: when in use
Figure 914071DEST_PATH_IMAGE008
Sorting according to the y-axis direction; when in use
Figure 414323DEST_PATH_IMAGE009
And then sorting according to the x-axis direction.
Further, the method for extracting the point cloud data Dc of the coordinate interval where the section S is located includes:
Figure 834940DEST_PATH_IMAGE010
further, the method for calculating the normal vector n of the section S includes:
Figure 361037DEST_PATH_IMAGE011
where i is the slope of the section S.
Further, the method for calculating the finely extracted cross-section point set Dp comprises the following steps:
Figure 474487DEST_PATH_IMAGE012
wherein d is the thickness of the extracted section, the value of d is 0.5-1 cm,
Figure 399717DEST_PATH_IMAGE013
is the 2 norm of the vector n.
Further, the method for converting the cross-section point set Dp into a planar coordinate system includes:
Figure 686342DEST_PATH_IMAGE014
the technical scheme of the invention has the following beneficial effects:
(1) the invention relates to a tunnel section rapid extraction method based on original point cloud data, which comprises the steps of calculating a center coordinate and a normal vector of a section to be extracted by collecting a tunnel section design drawing and a flat curve element table and a vertical curve element table of an interval where a tunnel is located; through two times of extraction, coarse extraction and fine extraction, 90% of point cloud data can be filtered out through the coarse extraction operation, so that the calculation efficiency is improved, the extracted section coordinate data is finally obtained, and the extracted section coordinate data can be converted into a plane coordinate system according to the requirement.
(2) The method for rapidly extracting the tunnel section based on the original point cloud data is rigorous in theory, convenient to implement, capable of simply, efficiently and accurately extracting the coordinate information of any section of the tunnel, and capable of providing important technical support for full-section tunnel monitoring methods such as three-dimensional laser scanning and the like, such as vault crown settlement monitoring, peripheral displacement monitoring, section clearance detection, lining thickness detection and the like.
In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 is a point cloud plot of original coordinates of a tunnel;
FIG. 2 is a cross-sectional profile plan of a tunnel;
FIG. 3 is a diagram of a coordinate interval where a tunnel section S is located;
FIG. 4 is the principle of crude extraction of the tunnel section S (k < 1);
FIG. 5 is a schematic diagram of rough extraction and fine extraction of a tunnel section S;
FIG. 6 is a three-dimensional graph of a tunnel section S;
fig. 7 is a two-dimensional graph of a tunnel section S.
Detailed Description
Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.
Example 1:
referring to fig. 1 to 7, a method for rapidly extracting a tunnel cross section based on original point cloud data is applied to monitoring and measuring a tunnel of a highway in Guangdong.
A tunnel section rapid extraction method based on original point cloud data comprises the following steps:
the method comprises the following steps: collecting tunnel section design drawing, route flat curve element table and vertical curve element table of the section where the tunnel section design drawing is located, and tunnel surface original coordinate point cloud data obtained by scanning
Figure 747839DEST_PATH_IMAGE001
Figure DEST_PATH_IMAGE016AA
Representing a point cloud, in which the subscripts
Figure DEST_PATH_IMAGE018AA
Represents a natural number; point cloud data
Figure 156824DEST_PATH_IMAGE001
Belonging to the left-hand coordinate system, i.e. the x-axis points in the north direction and the y-axis points in the east direction.
Step two: calculating a slope k of the section S to be extracted, and sequencing the original coordinate point cloud data Dr along the x-axis or y-axis direction of a coordinate axis according to the value of k to obtain sequenced point cloud data Ds; when in use
Figure 631667DEST_PATH_IMAGE008
Sorting according to the y-axis direction; when in use
Figure 659666DEST_PATH_IMAGE009
And then sorting according to the x-axis direction.
The calculation method of the slope k comprises the following steps:
Figure 903566DEST_PATH_IMAGE004
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE006AAAAA
is the azimuth angle of the line element starting point coordinate, R is the radius of the circular curve,
Figure 155556DEST_PATH_IMAGE007
in order to moderate the curve length, s is the distance from the calculated section to the starting point of the line element, F is a sign parameter, F is-1 when the line element is deviated from the left, and F is 1 when the line element is deviated from the right.
Step three: roughly extracting point cloud data, namely extracting point cloud data Dc of a coordinate interval where the section S is located from the sorted tunnel original coordinate point cloud data Ds according to the tunnel clearance width L and the slope k; as shown in fig. 4, the method for extracting the point cloud data Dc in the coordinate interval where the section S is located includes:
Figure 117695DEST_PATH_IMAGE010
in the formula (I), the compound is shown in the specification,
Figure DEST_PATH_IMAGE020AA
is a coordinate value of the coordinate value,
Figure DEST_PATH_IMAGE022AA
the coordinate values are the center coordinates.
The rough extraction operation can filter out 90% of point cloud data, thereby improving the calculation efficiency.
Step four: accurately extracting point cloud data, and calculating a central three-dimensional coordinate O at the section S to be extracted
Figure DEST_PATH_IMAGE003AAAAA
And calculating a point set Dp of the section to be extracted according to a distance formula from the point to the plane by using the normal vector n. The method for calculating the normal vector n of the section S comprises the following steps:
Figure 811369DEST_PATH_IMAGE011
where i is the slope of the section S.
The method for calculating the finely extracted section point set Dp comprises the following steps:
Figure 440934DEST_PATH_IMAGE012
wherein d is the thickness of the extracted section, the value of d is 0.5-1 cm,
Figure 801508DEST_PATH_IMAGE013
is the 2 norm of the vector n.
Step five: the extracted cross-section point set Dp is converted to a planar coordinate system. The method for converting the cross section point set Dp into the plane coordinate system comprises the following steps:
Figure 985365DEST_PATH_IMAGE014
wherein, R represents a rotation matrix, and Dt is a plane point set.
The tunnel section rapid extraction method based on the original point cloud data is rigorous in theory, convenient to implement, capable of simply, efficiently and accurately extracting coordinate information of any section of a tunnel, and capable of providing important technical support for full-section tunnel monitoring methods such as three-dimensional laser scanning and the like, such as vault settlement monitoring, peripheral displacement monitoring, section clearance detection, lining thickness detection and the like.
In this embodiment, a three-dimensional laser scanner is used to scan the surface of a highway tunnel in Guangdong to obtain an original point cloud coordinate, xyz file (the visualization result is shown in fig. 1). And a section profile (as shown in figure 2), a flat curve element table and a vertical curve element table are collected through a design document. The concrete working flow of extracting the section at a certain pile number of the tunnel is as follows:
(1) as shown in fig. 2, the tunnel section clearance length L =11.77m, and the center coordinate O (2491170.127,480573.6779,181.6866), the slope k =1.0249, and the normal vector n (0.6983, 0.7157, 0.0103) at the section S are calculated according to the design route information.
(2) Due to | k | >1, the original coordinate point cloud data is sorted according to the y axis, and the y axis interval range where the section S is located is calculated (as shown in fig. 4).
(3) And d =0.5 cm is taken, and points meeting the conditions are selected according to formula calculation to form a three-dimensional point set of the section S (as shown in the attached figure 6).
(4) Converting the three-dimensional point set of the section S into a plane coordinate system according to a coordinate conversion formula (as shown in FIG. 7)
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A tunnel section rapid extraction method based on original point cloud data is characterized by comprising the following steps:
the method comprises the following steps: collecting tunnel section design drawing, route flat curve element table and vertical curve element table of the section where the tunnel section design drawing is located, and tunnel surface original coordinate point cloud data D obtained by scanningr{Dr|pi(xi,yi,zi)∈Dr};
Step two: calculating a slope k of the section S to be extracted, and sequencing the original coordinate point cloud data Dr along the x-axis or y-axis direction of a coordinate axis according to the value of k to obtain sequenced point cloud data Ds;
step three: roughly extracting point cloud data, namely extracting point cloud data Dc of a coordinate interval where the section S is located from the sorted tunnel original coordinate point cloud data Ds according to the tunnel clearance width L and the slope k;
step four: accurately extracting point cloud data, and calculating a central three-dimensional coordinate O (x) of a section S to be extracted0,y0,z0) Andcalculating a point set Dp of the section to be extracted according to a distance formula from a point to a plane by using a normal vector n;
the method for calculating the finely extracted section point set Dp comprises the following steps:
Figure FDA0002383518370000011
wherein d is the extracted section thickness, the value of d is 0.5-1 cm, | | n | count2Is the 2 norm of the vector n.
2. The method for rapidly extracting the tunnel section based on the original point cloud data as claimed in claim 1, wherein the calculation method of the slope k is as follows:
Figure FDA0002383518370000012
wherein α is the azimuth of the line element starting point coordinate, R is the radius of the circular curve, l is the length of the easement curve, s is the distance from the calculated section to the starting point of the line element, F is the sign parameter, F is-1 when the line element is deviated to the left, and F is 1 when the line element is deviated to the right.
3. The method for rapidly extracting a tunnel section based on original point cloud data of claim 1, wherein the ordering rule of the original coordinate point cloud data Dr in the second step is as follows: when the | k | is more than or equal to 1, sorting according to the y-axis direction; when | k | <1, sorting is performed in the x-axis direction.
4. The method for rapidly extracting the tunnel section based on the original point cloud data as claimed in claim 1, wherein the method for extracting the point cloud data Dc in the coordinate interval where the section S is located is as follows:
Figure FDA0002383518370000021
Figure FDA0002383518370000022
in the formula, L represents a tunnel headroom width.
5. The method for rapidly extracting the tunnel section based on the original point cloud data as claimed in claim 1, wherein the normal vector n of the section S is calculated by:
Figure FDA0002383518370000023
where i is the slope of the section S.
6. The method for rapidly extracting the tunnel section based on the original point cloud data according to any one of claims 1 to 5, characterized by further comprising the following five steps: the extracted cross-section point set Dp is converted to a planar coordinate system.
7. The method for rapidly extracting a tunnel section based on original point cloud data as claimed in claim 6, wherein the method for converting the section point set Dp into a plane coordinate system is as follows:
Dt={pi∈Dp:(pi-O)·R};
Figure FDA0002383518370000024
where R represents the rotation matrix and α is the azimuth of the line element origin coordinate.
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