CN106441222B - Route section plotting board and method based on digital photographing - Google Patents

Abstract

The invention discloses a line cross-section surveying and mapping device and method based on digital photography. The device includes M benchmarks and surveying and mapping terminals, wherein M=2n+1, n is an integer and n≥1; the benchmarks include a main pole and a positioning block , the connection position between the main rod and the positioning block is provided with a first rotating shaft, and two slave rods located on both sides of the main rod are installed on the first rotating shaft, and the upper part of the main rod is provided with a second rotating shaft for the first laser emitter Two rotating shafts, the surveying and mapping terminal includes a tripod, a mount, a digital camera, a second laser transmitter and a computer; the method includes steps: 1. Determine the plane position of the surveyed and mapped line cross-section; 2. Determine the position of the digital camera and collect images Upload the information to the computer; 3. Process the image information and calculate the coordinates of each benchmark; 4. Transform the spatial coordinate system; 5. Draw the cross-section of the line. The invention has the advantages of simple and convenient operation and portability, high speed of measuring and drawing the cross-section of the line, high precision of computer processing, and wide application range.

Description

Device and method for line cross-section surveying and mapping based on digital photography

technical field

The invention belongs to the technical field of cross-section surveying and mapping, and in particular relates to a digital camera-based line cross-section surveying and mapping device and method.

Background technique

In the early stage of line design, it is necessary to conduct cross-sectional surveying and mapping of the places where the line passes, the purpose of which is to calculate the preliminary design of the line and the engineering quantity. The traditional cross-section surveying method mainly includes using total station or GPS-RTK to survey and map the cross-section of the line trend. The speed of the total station to measure the cross-section is very slow, and it is difficult to operate in some areas with complex terrain; use GPS -Although RTK can improve the measurement speed, in some areas where the reception of satellite signals is relatively poor, GPS-RTK cannot receive satellite signals at all, its accuracy and speed will be greatly affected, and the input cost is high. Therefore, there is a lack of a line cross-section surveying and mapping device and method based on digital photography that is low in cost, simple to operate, easy to carry, and reduces the number of times satellite communications are used. The position of the line cross section is found by multiple benchmarks and taken by an ordinary digital camera. The multiple benchmarks arranged in the same plane convert the actual data through the deformation of the distance parameters in the image and the reduction factor, and the computer processing speed is fast, which can solve the surveying and mapping of the cross-section of the line in areas that cannot be measured by other existing instruments.

Contents of the invention

The technical problem to be solved by the present invention is to provide a line cross-section surveying and mapping device based on digital photography, which is novel and reasonable in design, easy to operate and carry, fast in measuring and drawing the line cross-section, and computer processing. The utility model has the advantages of high precision, wide application range and convenient popularization and use.

In order to solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a line cross-section surveying and mapping device based on digital photography, which is characterized in that it includes M benchmarks inserted on the ground and used to determine the position of the line cross-section, and are arranged on the A surveying and mapping terminal used to collect and process benchmark parameters on one side of the line cross section, where M=2n+1, n is an integer and n≥1; the benchmark includes a main pole and a positioning block arranged at the bottom of the main pole, and the main pole and the positioning block There is a first rotating shaft at the connection position of the first rotating shaft, and two slave rods are installed on the first rotating shaft. The two slave rods are respectively located on both sides of the main rod. The rotating shaft, the main rod, the slave rod and the first laser emitter are located on the same plane; the surveying and mapping terminal includes a tripod, a mount mounted on the tripod and a digital camera mounted on the mount, and the lens in the digital camera is directly above or A second laser emitter perpendicular to the line cross-section is installed directly below, and the signal output end of the digital camera is connected with the computer.

The above-mentioned line cross-section surveying and mapping device based on digital photography is characterized in that: the line cross-section is located on the plane where the M benchmarks arranged coplanarly are located.

The above-mentioned line cross-section surveying and mapping device based on digital photography is characterized in that: among the M markers, the marker at the middle position is a middle stake marker, and the middle stake marker is installed on the center line of the road.

The above-mentioned line cross-section surveying and mapping device based on digital photography is characterized in that: the laser beam emitted by the second laser emitter is perpendicular to the line cross-section and is located on the straight line where the main pole of the middle stake is located.

The above-mentioned line cross-section surveying and mapping device based on digital photography is characterized in that: the main rod and the slave rod are telescopic rods, and the length of the telescopic rods is l Satisfy: 1m≤l≤1.5m.

The above-mentioned line cross-section surveying and mapping device based on digital photography is characterized in that: the rotation angle between the slave rod around the first rotation axis and the main rod is 0°-90°.

At the same time, the invention also discloses a line cross-section surveying and mapping method with simple method steps, reasonable design, and the actual distance can be calculated through the deformation of the photo image, which is characterized in that the method includes the following steps:

Step 1. Determine the plane position of the surveyed and mapped line cross-section: first, install the middle stake mark on the center line of the road, fully expand the two slave bars of the middle stake mark, and adjust the height of the middle stake mark. Azimuth, determine the reference position of the line cross-section; then, install N benchmarks on both sides of the middle stake marker, and open the respective first laser transmitters in the 2N markers to scan the plane where the middle stake marker is located , determine the cross-section of the surveyed and mapped line, wherein, N=2n-1, the middle pile point is installed on the middle pile point obtained by satellite detection, and the coordinates of the middle pile point are known;

Step 2. Determine the position of the digital camera and collect image information and upload it to the computer: first, adjust the laser beam emitted by the second laser emitter to shoot perpendicularly to the cross-section of the line and the laser beam emitted by the second laser emitter is in line with the The straight lines where the main poles in the middle stake benchmarks intersect; then, adjust the focal length of the digital camera, place the markers on both sides of the M markers close to the inside of the boundary of the field of view in the digital camera, press the shutter to obtain the image information of the M markers and the Upload the image information to the computer;

Step 3, image information processing and calculation of the coordinates of each benchmark: calibrate the position of each marker on the image, find the position of the middle stake marker, and establish a rectangular coordinate system o-xz with the first rotation axis of the middle stake marker as the coordinate origin , taking the straight line where the main pole of the middle pile benchmark is located as the z-axis of the Cartesian coordinate system o-xz, taking the straight line where the secondary pole of the middle pile benchmark is located as the x-axis of the rectangular coordinate system o-xz, by the Calculate the coordinates of each benchmark on both sides of the middle stake benchmark, and the calculation methods of the coordinates of the two adjacent benchmarks are the same;

When calculating the coordinates of two adjacent benchmarks to be calculated, the process is as follows:

Step 301, setting auxiliary points: Auxiliary points A are randomly generated on the slope between two adjacent benchmarks on the image by computer;

Step 302, according to the formula In step 301, the deformation coefficient k ₁ of the benchmark pole located at the auxiliary point A along the x-axis direction and the deformation coefficient k ₂ of the benchmark pole located at the other side of the auxiliary point A along the x-axis direction in step 301, wherein, i is the pole expanded from the pole , i=1 or 2, _{la ai} is the length of the i-th slave rod corresponding to the benchmark with a deformation coefficient of k ₁ on the image, l _bi is the length of the i-th slave rod corresponding to the benchmark with a deformation coefficient of k ₂ on the image ;

Step 303, according to the formula Calculate the deformation coefficient k _A at the auxiliary point A along the x-axis direction, where s _a is the distance from the auxiliary point A to the benchmark on the side of the auxiliary point A on the image along the x-axis direction, and s _b is the distance between the auxiliary point A along the x-axis The distance between the direction and the pole on the other side of the auxiliary point A on the image;

Step 304, according to the formula Calculate the distance L _x between two adjacent landmarks in the x-axis direction, where L _a is the actual distance corresponding to the distance parameter s _a on the image in the actual site, and L _b is the distance parameter s _b on the image in the actual site the corresponding actual distance;

Step 305, according to the formula In step 301, the deformation coefficient k ₁ ' of the pole on one side of the auxiliary point A along the z-axis direction and the deformation coefficient k' ₂ of the pole on the other side of the auxiliary point A along the z-axis direction are calculated, wherein l' _a is the image The upper deformation coefficient is the length of the main pole corresponding to the benchmark pole with a deformation coefficient of k ₁ ', l _b ' is the length of the main pole corresponding to the benchmark pole with a deformation coefficient of k' ₂ on the image;

Step 306, according to the formula Calculate the deformation coefficient k' _A at the auxiliary point A along the z-axis direction, where s' _a is the distance from the auxiliary point A to the pole on the side of the auxiliary point A on the image along the z-axis direction, and s' _b is the auxiliary point A The distance along the z-axis from the pole on the other side of the auxiliary point A on the image;

Step 307, according to the formula Calculate the distance L _z between two adjacent landmarks in the z-axis direction, where L' _a is the actual distance corresponding to the distance parameter s' _a on the image in the actual field, and L _b is the distance parameter s' _b on the image The corresponding actual distance in the actual site;

Step 308, repeating step 302 to step 307 multiple times until the calculation process of the coordinates of each benchmark in the rectangular coordinate system o-xz is completed;

Step 4, space coordinate system transformation: the coordinate transformation of the coordinates of the M benchmarks distributed in the rectangular coordinate system o-xz is carried out by the computer using the coordinate transformation method, and the coordinates of the M benchmarks in the rectangular coordinate system o-xz are converted to On the ginseng coordinate system or the geocentric coordinate system, obtain the actual spatial coordinates of the M benchmarks in the ginseng coordinate system or the geocentric coordinate system;

Step 5. Drawing of the cross-section of the line: the computer smoothly connects the actual spatial coordinates of the M benchmarks obtained in step 4 along the increasing direction of the x-coordinate, and draws the cross-section of the line.

Compared with the prior art, the present invention has the following advantages:

1. The benchmark pole in the line cross-section surveying and mapping device based on digital photography adopted in the present invention is fixed on the ground by inserting the positioning block underground, and two slave poles are rotated on the first rotating shaft. One slave rod or one of the two slave rods is used as the measurement reference in the horizontal direction, and both the slave rod and the main rod can be retracted, the structure is simple, and it is convenient to carry.

2. In the line cross-section surveying and mapping device based on digital photography adopted by the present invention, a plurality of benchmarks are photographed by a digital camera to obtain line cross-section parameters, and the actual data is converted by the deformation of the distance parameters on the image and the zoom factor, and the data is processed by a computer. Fast, reliable and stable.

3. The digital photography-based line cross-section surveying and mapping method used in the present invention has simple steps. By establishing a rectangular coordinate system o-xz, the distance deformation and zooming in the horizontal direction of the x-axis and the vertical direction of the z-axis are calculated respectively. Through the conversion of the spatial coordinate system, the coordinates of each benchmark on the line cross-section are converted to the ginseng coordinate system or the geocentric coordinate system, and the drawing of the line cross-section is convenient, quick and efficient.

4. The present invention is novel and reasonable in design, low in investment cost, simple in operation, convenient to carry, reduces dependence on satellite communication, has strong practicability, and is easy to popularize and use.

To sum up, the present invention has novel and reasonable design, simple and convenient operation and portability, high speed of measuring and drawing the cross-section of the line, high precision of computer processing, wide application range, and easy popularization and use.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the use status diagram of the line cross-section surveying and mapping device based on digital photography adopted in the present invention.

Fig. 2 is a structural schematic diagram of a benchmark in the line cross-section surveying and mapping device of the present invention.

Fig. 3 is a schematic diagram of the positional relationship between two adjacent benchmarks in the Cartesian coordinate system o-xz in the digital photography-based line cross-section surveying and mapping method of the present invention.

Fig. 4 is a method block diagram of the digital photography-based line cross-section surveying and mapping method of the present invention. Explanation of reference signs:

1—benchmark; 1-1—first rotating shaft; 1-2—slave pole;

1-3—positioning block; 1-4—main rod; 1-5—second rotating shaft;

1-6—first laser emitter; 2—line cross section; 3—digital camera;

4—mounting base; 5—tripod; 7—computer.

detailed description

As shown in Fig. 1 and Fig. 2, the line cross-section mapping device based on digital photography according to the present invention includes M marker posts 1 that are inserted on the ground and are used to determine the position of the line cross-section 2, and are arranged on the line One side of the cross-section 2 is used to collect and process the surveying and mapping terminal of the parameters of the benchmark 1, where M=2n+1, n is an integer and n≥1; the benchmark 1 includes the main pole 1-4 and the positioning set at the bottom of the main pole 1-4 Block 1-3, the connecting position of main rod 1-4 and positioning block 1-3 is provided with first rotating shaft 1-1, and two slave rods 1-2 are installed on the first rotating shaft 1-1, two slave rods Rod 1-2 is respectively positioned at the both sides of master rod 1-4, and the top of master rod 1-4 is provided with the second rotating shaft 1-5 that rotates for first laser transmitter 1-6, and master rod 1-4, slave rod 1-2 and the first laser emitter 1-6 are located on the same plane; the surveying and mapping terminal includes a tripod 5, a mount 4 installed on the tripod 5 and a digital camera 3 installed on the mount 4, in the digital camera 3 A second laser emitter perpendicular to the line cross-section 2 is installed directly above or directly below the lens, and the signal output terminal of the digital camera 3 is connected with a computer 7 .

In this embodiment, among the M marker posts 1 , the marker post 1 at the middle position is a middle stake marker, and the middle stake marker is installed on the center line of the road.

In actual use, the cross section of the line includes the cross section of the road, the cross section of the road, the cross section of the river bed, the cross section of the belt-like features or the cross section of the green belt, etc. On the middle pile point, the middle pile point is the position detected in advance and the middle pile point is located on the center line of the road, adjust the orientation of the middle pile benchmark, and the positioning block 1-3 is installed on the middle pile point.

In this embodiment, the line cross-section 2 is located on the plane where the M poles 1 arranged in the same plane are located.

In this embodiment, the rotation angle between the slave rod 1-2 around the first rotating shaft 1-1 and the main rod 1-4 is 0°-90°.

After the positioning block 1-3 is installed on the middle pile point, fully expand the slave rod 1-2 to both sides of the main rod 1-4, make the slave rod 1-2 unfold 90° perpendicular to the main rod 1-4, and turn on the first laser Transmitter 1-6 and make the first laser transmitter 1-6 rotate around the second rotating shaft 1-5 to emit the laser beam, and the expansion in the pole 1 adjacent to the middle pile pole is swept along the laser beam from the pole 1-2 Plane layout of the surface, open the first laser emitter 1-6 in the benchmark 1 and rotate the scanning plane equally, so that the expansion in the next benchmark 1 is laid out along the plane of the laser beam scanning plane from the pole 1-2, and so on, no Let me repeat.

When the pole 1 is actually placed on the ground, the position of the pole 1 is not necessarily flat, so that the two slave poles 1-2 of the pole 1 cannot be rotated by 90°. At this time, according to the terrain, ensure that the two slave poles 1 - One of the secondary poles 1-2 in -2 is fully expanded and kept perpendicular to the main pole 1-4, ensuring the reliability of image data captured by the digital camera 3.

In this embodiment, the laser beam emitted by the second laser emitter is perpendicular to the line cross-section 2 and is located on the straight line where the main pole 1-4 of the center pile marker is located.

In this embodiment, the M poles 1 are extended and arranged on both sides of the center pole, and the second laser emitter is used to emit a laser beam perpendicular to the line cross section 2 and located on the main pole 1 of the center pole. On the straight line where -4 is located, ensure that the digital camera 3 is facing the measurement center formed by M benchmarks 1. At this time, the image data acquired by the digital camera 3 has the smallest deformation, the calculation error is small, and unnecessary data brought when acquiring data is reduced. noise.

In this embodiment, both the main rod 1-4 and the slave rod 1-2 are telescopic rods, and the length of the telescopic rods is l Satisfy: 1m≤l≤1.5m.

In actual operation, when the benchmark 1 is not used, the main pole 1-4 and the slave pole 1-2 are retracted to the shortest distance, which is convenient to carry. When the benchmark 1 is used, the main pole 1-4 and the slave pole 1-2 are stretched to The longest distance reduces the ratio of image data to actual distance, thereby improving calculation accuracy.

As shown in Figure 3 and Figure 4, a method of utilizing the device according to claim 1 to carry out line cross-section surveying and mapping, comprising the following steps:

Step 1. Determine the plane position of the surveyed and mapped line cross-section: first, install the middle stake pole on the center line of the road, fully expand the two slave bars 1-2 of the middle stake pole, and adjust the middle pole. The azimuth angle of the stake pole is used to determine the reference position of the line cross section 2; then, N poles 1 are respectively installed on both sides of the middle pole pole, and the respective first laser transmitters 1-6 in the 2N poles 1 are turned on to scan On the plane where the middle stake pole is located, determine the line cross-section 2 surveyed and mapped, wherein, N=2n-1, the middle stake pole is installed on the middle stake point obtained by satellite detection, and the coordinates of the middle stake point are known;

In this embodiment, among the M marker posts 1 placed on the ground, avoid crossing the ridge or valley between two adjacent marker posts 1 to ensure the correctness of the surveying and mapping of the line cross-section 2; A benchmark 1 obtains the turning direction of the line cross section 2, and the benchmark 1 is placed on the continuously rising or descending slope according to the effective distance scanned by the laser beam to ensure an effective measurement distance interval.

Step 2. Determine the position of the digital camera and collect image information and upload it to the computer: first, adjust the laser beam emitted by the second laser emitter to shoot perpendicularly to the line cross-section 2 and the laser beam emitted by the second laser emitter is consistent with the The straight lines where the main poles 1-4 in the middle pile benchmarking poles intersect; then, adjust the focal length of the digital camera 3, and place the benchmarking poles 1 on both sides of the M benchmarking poles 1 close to the inside of the boundary of the field of view in the digital camera 3, and press the shutter to obtain M image information of a benchmark 1 and upload the image information to a computer 7;

When actually taking pictures, try to ensure that the outermost two benchmarks 1 of the M benchmarks 1 are close to the boundary of the field of view of the digital camera 3, and use the field of view of the digital camera 3 while ensuring that all the M benchmarks 1 are captured, to avoid M The benchmarks 1 are gathered in the middle of the photo, the ratio of the actual benchmarks 1 to the benchmarks on the image is enlarged, and the processing accuracy of the computer 7 is reduced.

Step 3, image information processing and calculation of the coordinates of each benchmark: calibrate the position of each marker 1 on the image, find the position of the middle stake marker, and establish a rectangular coordinate with the first rotation axis 1-1 of the middle stake marker as the coordinate origin System o-xz, take the straight line where the main pole 1-4 of the middle pile benchmark is located as the z-axis of the Cartesian coordinate system o-xz, and take the straight line where the secondary pole 1-2 of the middle pile benchmark is located as the rectangular coordinate system For the x-axis of o-xz, the coordinates of each benchmark 1 are calculated from the middle stake benchmark to its two sides, and the coordinate calculation methods of two adjacent benchmarks 1 are the same;

When calculating the coordinates of two adjacent benchmarks 1 to be calculated, the process is as follows:

Step 301, setting auxiliary points: use the computer 7 to randomly generate auxiliary points A on the slope between two adjacent benchmarks on the image;

Step 302, according to the formula In step 301, the deformation coefficient k ₁ of the benchmark pole located at the auxiliary point A along the x-axis direction and the deformation coefficient k ₂ of the benchmark pole located at the auxiliary point A along the x-axis direction in step 301, wherein, i is the secondary pole of the benchmark pole 1 1-2 The number of expansions, i=1 or 2, _{la ai} is the length of the i-th slave bar corresponding to the benchmark with a deformation coefficient of k ₁ on the image, l _bi is the benchmark with a deformation coefficient of k ₂ on the image corresponding to the i-th from the length of the rod;

It should be noted that the actual terrain fluctuations are uncertain. When the position where the benchmark 1 is installed is flat, the two slave poles 1-2 of the benchmark 1 can be expanded, and the deformation coefficient error can be reduced by taking the average; when the position where the benchmark 1 is placed is bad, When the two slave poles 1-2 cannot be fully expanded, ensure that one of the two slave poles 1-2 is deployed to a horizontal position. When actually selecting the placement position of the marker pole 1, try to choose a flat position so that the marker pole 1 is fully deployed.

Step 303, according to the formula Calculate the deformation coefficient k _A at the auxiliary point A along the x-axis direction, where s _a is the distance from the auxiliary point A to the benchmark on the side of the auxiliary point A on the image along the x-axis direction, and s _b is the distance between the auxiliary point A along the x-axis The distance between the direction and the pole on the other side of the auxiliary point A on the image;

Step 304, according to the formula Calculate the distance L _x between two adjacent landmarks 1 in the x-axis direction, where L _a is the actual distance corresponding to the distance parameter s _a on the image in the actual site, and L _b is the distance parameter s _b on the image in the actual site The corresponding actual distance in

In this embodiment, the distance between the corresponding benchmark 1 and the middle stake benchmark is calculated from the middle stake benchmark to its two sides, wherein the coordinates of the middle stake benchmark are known, and the position of the new benchmark can be quickly determined through displacement changes coordinate.

Step 305, according to the formula In step 301, the deformation coefficient k ₁ ' of the pole on one side of the auxiliary point A along the z-axis direction and the deformation coefficient k' ₂ of the pole on the other side of the auxiliary point A along the z-axis direction are calculated, wherein l' _a is the image The upper deformation coefficient is the length of the main pole corresponding to the benchmark pole with a deformation coefficient of k ₁ ', l _b ' is the length of the main pole corresponding to the benchmark pole with a deformation coefficient of k' ₂ on the image;

It should be noted that the inverted T-shaped benchmark 1 is actually used, and there is only one main pole 1-4 of the benchmark 1, which will not be blocked, and the displacement change in the z-axis direction is directly measured and calculated.

Step 306, according to the formula Calculate the deformation coefficient k' _A at the auxiliary point A along the z-axis direction, where s' _a is the distance from the auxiliary point A to the pole on the side of the auxiliary point A on the image along the z-axis direction, and s' _b is the auxiliary point A The distance along the z-axis from the pole on the other side of the auxiliary point A on the image;

Step 307, according to the formula Calculate the distance L _z between two adjacent landmarks 1 in the z-axis direction, where L' _a is the actual distance corresponding to the distance parameter s' _a on the image in the actual scene, and L _b is the distance parameter s' _b on the image The corresponding actual distance in the actual site;

Step 308, repeat step 302 to step 307 multiple times until the calculation process of the coordinates of each benchmark 1 in the rectangular coordinate system o-xz is completed;

Step 4, space coordinate system conversion: the computer 7 adopts the coordinate transformation method to carry out coordinate transformation on the coordinates of the M benchmarks 1 distributed in the rectangular coordinate system o-xz, and converts the coordinates of the M benchmarks 1 in the rectangular coordinate system o-xz The coordinates are converted to the ginseng coordinate system or the geocentric coordinate system, and the actual space coordinates of the M benchmarks 1 in the ginseng coordinate system or the geocentric coordinate system are obtained;

In actual use, my country's ginseng coordinate system mainly includes the 1954 Beijing coordinate system and the 1980 Xi'an coordinate system, and the geocentric coordinate system mainly includes the 2000 China Geodetic Coordinate System (CGCS2000) and the 1984 World Geodetic Coordinate System (WGS84).

Step 5. Drawing the cross-section of the line: the computer 7 smoothly connects the actual spatial coordinates of the M benchmarks 1 obtained in step 4 along the increasing direction of the x-coordinate, and draws the cross-section of the line.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any way. All simple modifications, changes and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still belong to the technical aspects of the present invention. within the scope of protection of the scheme.

Claims (3)

1. The line cross-section surveying and mapping device based on digital photography, is characterized in that: comprise M and be placed on the ground and be used for determining the benchmark post (1) of line cross-section (2) position, and be arranged on described line cross-section (2) ) one side is used to collect and process the surveying and mapping terminal of the parameters of the benchmark (1), wherein M=2n+1, n is an integer and n≥1; the benchmark (1) includes the main pole (1-4) and is set on the main pole (1 -4) The positioning block (1-3) at the bottom, the connection position between the main rod (1-4) and the positioning block (1-3) is provided with a first rotating shaft (1-1), the first rotating shaft (1-1 ) are installed with two slave rods (1-2) for rotation, and the two slave rods (1-2) are respectively located on both sides of the main rod (1-4), and the upper part of the main rod (1-4) is provided with a A second rotating shaft (1-5) that a laser emitter (1-6) rotates, the main rod (1-4), the slave rod (1-2) and the first laser emitter (1-6) are located on the same plane The surveying and mapping terminal comprises a tripod (5), a mount (4) installed on the tripod (5) and a digital camera (3) installed on the mount (4), directly above the lens in the digital camera (3) Or a second laser transmitter perpendicular to the line cross-section (2) is installed directly below, and the signal output terminal of the digital camera (3) is connected to the computer (7); The benchmark post (1) at the middle position among the M benchmark posts (1) is a mid-stake benchmark, and the mid-stake benchmark is installed on the center line of the road; The laser beam emitted by the second laser emitter is perpendicular to the line cross-section (2) and is located on the straight line where the main pole (1-4) of the middle pile mark is located; Both the main rod (1-4) and the slave rod (1-2) are telescopic rods, and the length of the telescopic rods is l Satisfy: 1m≤l≤1.5m; The rotation angle between the slave rod (1-2) around the first rotating shaft (1-1) and the master rod (1-4) is 0°-90°. 2. The line cross-section surveying and mapping device based on digital photography according to claim 1, characterized in that: said line cross-section (2) is located on the plane where M marker posts (1) are arranged coplanarly. 3. A method utilizing the device according to claim 1 to carry out line cross-section surveying and mapping, characterized in that the method may further comprise the steps: Step 1, determine the plane position of the surveyed and mapped line cross-section: first, install the middle stake pole on the center line of the road, fully expand the two slave bars (1-2) of the middle stake pole, adjust the Describe the azimuth angle of the middle pile benchmark, determine the reference position of the line cross section (2); then, install N benchmarks (1) respectively on both sides of the middle pile benchmark, and open the respective No. A laser emitter (1-6) scans the plane where the middle stake pole is located, and determines the surveyed and mapped line cross-section (2), wherein, N=2n-1, and the middle stake pole is installed on the ground obtained by satellite detection. On the middle stake point, the coordinates of the middle stake point are known; Step 2. Determine the position of the digital camera and collect image information and upload it to the computer: first, adjust the laser beam emitted by the second laser emitter to shoot perpendicularly to the line cross section (2) and the laser beam emitted by the second laser emitter Intersect with the straight line where main pole (1-4) is located in the said middle pile benchmarking pole; Then, adjust the focal length of digital camera (3), the benchmarking pole (1) on both sides in M benchmarking poles (1) is close to digital camera (3 ) on the inner side of the boundary of the field of view, press the shutter to obtain the image information of the M benchmarks (1) and upload the image information to the computer (7); Step 3, image information processing and calculating the coordinates of each benchmark: calibrate the position of each marker (1) on the image, find the position of the middle stake marker, and take the first rotation axis (1-1) of the middle stake marker as the coordinate The origin establishes the rectangular coordinate system o-xz, takes the straight line where the main pole (1-4) of the middle stake benchmark post is the z axis of the rectangular coordinate system o-xz, and takes the slave bar (1-2) of the middle stake benchmark post as the z axis of the rectangular coordinate system o-xz ) is the x-axis of the Cartesian coordinate system o-xz, and the coordinates of each benchmark (1) are calculated from the middle stake benchmark to its two sides, and the coordinate calculation methods of two adjacent benchmarks (1) are the same; When calculating the coordinates of two adjacent benchmarks (1) to be calculated, the process is as follows: Step 301, setting auxiliary points: Auxiliary points A are randomly generated on the slope between two adjacent benchmarks on the image by computer (7); Step 302, according to the formula In step 301, the deformation coefficient k ₁ of the benchmark pole located at the auxiliary point A along the x-axis direction and the deformation coefficient k ₂ of the benchmark pole located at the auxiliary point A along the x-axis direction in step 301, wherein, i is the benchmark pole (1) The quantity expanded from the rod (1-2), i=1 or 2, _{la ai} is the length of the i-th slave rod corresponding to the benchmark with a deformation coefficient of k ₁ on the image, and l _bi is the benchmark with a deformation coefficient of k ₂ on the image Corresponding to the length of the i-th slave rod; Step 303, according to the formula Calculate the deformation coefficient k _A at the auxiliary point A along the x-axis direction, where s _a is the distance from the auxiliary point A to the benchmark on the side of the auxiliary point A on the image along the x-axis direction, and s _b is the distance between the auxiliary point A along the x-axis The distance between the direction and the pole on the other side of the auxiliary point A on the image; Step 304, according to the formula Calculate the distance L _x between two adjacent landmarks (1) in the x-axis direction, where L _a is the actual distance corresponding to the distance parameter s _a on the image in the actual scene, and L _b is the distance parameter s _b on the image The corresponding actual distance in the actual site; Step 305, according to the formula In step 301, the deformation coefficient k ₁ ' of the pole on one side of the auxiliary point A along the z-axis direction and the deformation coefficient k' ₂ of the pole on the other side of the auxiliary point A along the z-axis direction are calculated, wherein l' _a is the image The upper deformation coefficient is the length of the main pole corresponding to the benchmark pole with a deformation coefficient of k ₁ ', l _b ' is the length of the main pole corresponding to the benchmark pole with a deformation coefficient of k' ₂ on the image; Step 306, according to the formula Calculate the deformation coefficient k' _A at the auxiliary point A along the z-axis direction, where s' _a is the distance from the auxiliary point A to the pole on the side of the auxiliary point A on the image along the z-axis direction, and s' _b is the auxiliary point A The distance along the z-axis from the pole on the other side of the auxiliary point A on the image; Step 307, according to the formula Calculate the distance L _z between two adjacent landmarks (1) in the z-axis direction, where L' _a is the actual distance corresponding to the distance parameter s' _a on the image in the actual scene, and L _b is the distance parameter s on the image ' _b The corresponding actual distance in the actual site; Step 308, repeatedly repeating step 302 to step 307, until the calculation process of the coordinates of each benchmark (1) in the rectangular coordinate system o-xz is completed; Step 4, space coordinate system transformation: adopt coordinate transformation method to carry out coordinate transformation to the coordinates of M markerposts (1) distributed in the Cartesian coordinate system o-xz by computer (7), convert M in the Cartesian coordinate system o-xz The coordinates of the benchmark posts (1) are converted to the ginseng coordinate system or the geocentric coordinate system, and the actual space coordinates of the M benchmark posts (1) in the ginseng coordinate system or the geocentric coordinate system are obtained; Step 5, drawing the line cross-section: the computer (7) smoothly connects the actual space coordinates of the M benchmarks (1) obtained in step 4 along the direction of increasing x coordinates, and draws the line cross-section.