Three-dimensional laser scanning auxiliary device and reference system rotation method thereof

Abstract

The present application relates to a three-dimensional laser scanning auxiliary device and a reference system rotation method thereof. The existing device and method have problems such as heavy workload, dangerous operation, the need to re-level when adjusting height, and high redundancy of coordinate conversion method. The top of the triangular main support is provided with a scanning device connector for installing a three-dimensional laser scanner to obtain point cloud data of the measured surface and the cross target. The extension rod is horizontally arranged, one end of which is connected to the lower part of the triangular main support, and the other end is provided with a three-dimensional electronic compass display to obtain the inclination and inclination angle of the movable triangular iron plate. The movable triangular iron plate is located on the side and provided with a cross target. The cross target is arranged on the triangular main support, and no additional target frame is needed, reducing the workload. The cross target is located on the side and can be horizontally extended and retracted, and can be away from the side during erection, reducing the risk. The extension rod can move up and down, and there is no need to re-level when adjusting the height. The coordinate conversion is directly realized by using Euler angles and cosine matrix, reducing the redundancy.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional laser scanning, and more specifically to a three-dimensional laser scanning auxiliary device and a method for rotating its reference system. Background Technology

[0002] Three-dimensional laser scanning technology has been widely used in tunnel and rock slope surveying. Compared with traditional surveying methods, three-dimensional laser scanning acquires massive amounts of point cloud data based on various scanning devices, enabling a more comprehensive presentation of the three-dimensional structure of the measured object. During the scanning process, control points need to be set up and scanning equipment deployed to acquire point cloud data. The point cloud data obtained by the scanning equipment is in relative coordinates, and the point cloud data scanned from different control points are in different coordinate systems. Therefore, it is necessary to transform the relative coordinates to the same coordinate system to achieve multi-station stitching.

[0003] Rotating and unifying the coordinate reference systems of various scanning devices facilitates subsequent coordinate transformations, but requires setting up a large number of crosshairs as control points, resulting in a large workload and impacting implementation efficiency. Patent CN114858140A discloses a method and device for transforming the point cloud coordinates of a deep-buried tunnel structure surface based on a target device. In this target device, a first, second, and third plate are set on the top of a triangular target frame. Height adjusters are located below these plates. Three crosshairs are set on the third plate, which is close to the surface being measured, allowing the crosshairs to be marked on the surface without directly placing them on the side of the surface. However, this target device is merely a target-bearing structure with a single function. Combined with the assumptions of other equipment, this results in a significant workload. The third plate with the crosshair target is located at the top of the triangular target frame. When marking the crosshair target on the surface being measured, it needs to be close to the surface, posing a danger when scanning certain hazardous locations. After setting up the triangular target frame, adjusting the height of the crosshair target requires adjusting a height adjuster, necessitating releveling of the entire target device, which is quite cumbersome. Furthermore, its coordinate transformation method uses a rotation matrix, employing nine parameters to represent three degrees of freedom, resulting in significant redundancy. Summary of the Invention

[0004] The purpose of this invention is to provide a three-dimensional laser scanning auxiliary device and its reference system rotation method to solve the problems of existing equipment, such as large workload, dangerous operation, the need to readjust the entire device when adjusting the height of the crosshair target, and the high redundancy of existing methods.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A three-dimensional laser scanning auxiliary device, the device comprising a triangular main support, an extension rod, and a movable triangular iron plate;

[0007] The top of the triangular main support is provided with a scanning device connector for mounting a 3D laser scanner.

[0008] The extension rod is horizontally set, one end of which is movably connected to the lower part of the triangular main bracket, and the other end is provided with a hinge and connected to a movable rectangular steel plate. A three-dimensional electronic compass digital display is provided on the outside of the movable rectangular steel plate.

[0009] The movable triangular iron plate is an inverted equilateral triangle. The bottom of the movable triangular iron plate is connected to the top of the movable rectangular steel plate. The movable triangular iron plate includes three rectangular iron plates connected end to end, and a cross target is set at each of the three connection points.

[0010] After the movable triangular iron plate is brought close to the surface to be measured, the three-dimensional laser scanner is used to acquire point cloud data of the surface to be measured and the crosshair target, and the three-dimensional electronic compass digital display is used to acquire the inclination α1 and tilt angle β1 of the movable triangular iron plate.

[0011] Furthermore, the device also includes a first circular level and a second circular level;

[0012] The first circular level is mounted on the connector of the scanning device;

[0013] The second circular level is mounted on the extension rod.

[0014] Furthermore, the triangular main support includes three legs, and the bottom end of each leg is connected to a movable telescopic rod via a rotating tensioner.

[0015] Furthermore, one of the legs has a groove arranged along the length of the leg on its inner side, and one end of the extension rod is installed into the groove by a rotating tensioner.

[0016] On the other hand, a reference system rotation method is provided for a three-dimensional laser scanning auxiliary device, the method being implemented based on the aforementioned three-dimensional laser scanning auxiliary device, comprising:

[0017] Adjust the height of the main triangular support, the height of the extension rod, and the tilt angle of the movable triangular iron plate so that the movable triangular iron plate is close to the surface being measured, and so that the bubbles of the first and second circular levels are centered.

[0018] The point cloud data of the measured surface and the cross-shaped target are obtained by the three-dimensional laser scanner, and the point cloud coordinates of the three cross-shaped targets, P1(x1,y1,z1), P2(x2,y2,z2), and P3(x3,y3,z3), are extracted from the point cloud data respectively.

[0019] The compass inclination α1 and compass tilt angle β1 of the movable triangular iron plate are obtained by the digital display of the three-dimensional electronic compass.

[0020] The scanning tendency α2 and scanning tilt angle β2 of the movable triangular iron plate are determined based on P1, P2, and P3.

[0021] Calculate the normal vector n1 between α1 and β1, and the normal vector n2 between α2 and β2. Then calculate the angle θ between n1 and n2 and the rotation axis vector (r). x r y r z );

[0022] According to θ and (r) x r y r z Calculate the rotation angles α, β, and γ along the z-axis, y-axis, and x-axis respectively;

[0023] The rotation matrix is ​​obtained by combining θ with α, β, and γ;

[0024] The coordinates of the point cloud data are converted into geodetic coordinates using a rotation matrix.

[0025] Further, determining the scanning tendency α2 and scanning tilt angle β2 of the movable triangular iron plate based on P1, P2, and P3 includes:

[0026] Based on P1, P2, and P3, obtain the normal vector of the plane containing the crosshair target:

[0027]

[0028] Let the normal vector be (a1, b1, c1), and calculate the scanning inclination α2 and scanning tilt angle β2 of the plane where the crosshair target is located, i.e., the movable triangular iron plate, based on the normal vector:

[0029]

[0030] When b1 > 0

[0031]

[0032] When b1≤0

[0033]

[0034] Furthermore, calculate the normal vector n1 between α1 and β1, and the normal vector n2 between α2 and β2, and then calculate the angle θ between n1 and n2 and the rotation axis vector (r). x r y r z ),include:

[0035] Calculate n1 and n2:

[0036] n1=(n x1 n y1 n z1 )=(sinβ1cosα1 sinβ1sinα1 cosβ1);

[0037] n2=(n x2 n y2 n z2 )=(sinβ2cosα2 sinβ2sinα2 cosβ2);

[0038] Calculate θ based on n1 and n2:

[0039] cosθ=(n x1 ×n x2 +n y1 ×n y2 +n z1 ×n z2 ) / (sqrt(n x1 2 +n y1 2 +n z1 2 )×sqrt(n x2 2 +n y2 2 +n z2 2 ));

[0040] Calculate (r) based on the cross product of n1 and n2. x r y r z ):

[0041] r x =n y1 ×n z2 -n z1 ×n y2 ;

[0042] r y =n z1 ×n x2 -n x1 ×n z2 ;

[0043] r z =n x1 ×n y2 -n y1 ×n x2 .

[0044] Furthermore, according to θ and (rx r y r z Calculate the rotation angles α, β, and γ along the z-axis, y-axis, and x-axis respectively, including:

[0045] α=arctan(r z / r y );

[0046]

[0047] γ=arctan(r x / r z ).

[0048] Furthermore, combining θ with α, β, and γ yields the rotation matrix, including:

[0049] The rotation matrix along the z-axis is:

[0050]

[0051] The rotation matrix along the y-axis is:

[0052]

[0053] The rotation matrix along the x-axis is:

[0054]

[0055] Furthermore, the coordinates of the point cloud data are converted into geodetic coordinates using a rotation matrix, including:

[0056] If the coordinates obtained by the 3D laser scanner are (x0, y0, z0);

[0057] Converted to geodetic coordinates:

[0058]

[0059] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0060] The three-dimensional laser scanning auxiliary device provided by this invention connects a movable triangular iron plate with a crosshair target to a triangular main support, and sets the scanning equipment connector for mounting the three-dimensional laser scanner on the top of the triangular main support. It can both support the three-dimensional laser scanner and set the crosshair target. It is equivalent to directly setting the crosshair target, which serves as the control point, on the triangular main support of the three-dimensional laser scanner. There is no need to install a separate target frame, which is convenient to carry and reduces the workload.

[0061] The three-dimensional laser scanning auxiliary device provided by this invention features a movable triangular iron plate with a crosshair target located on the side of a triangular main support. Connected to the main support via an extension rod, the plate is laterally extendable. During setup, the plate can be initially moved away from the side to be scanned, and then the crosshair target can be pushed towards that side via the extension rod, reducing operational risks. Furthermore, the end of the extension rod can move up and down within a groove on the main support, allowing adjustment of the crosshair target's height simultaneously with the extension rod's height, without affecting other components or requiring readjustment.

[0062] The rotation method of the reference system of the three-dimensional laser scanning auxiliary device provided by the present invention directly uses Euler angles and cosine matrix to realize coordinate transformation. The calculation process is simple and intuitive, and only the rotation angles of the x, y and z axes need to be considered, which greatly reduces redundancy. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0064] Figure 1 This is a front view structural diagram of the device provided in the embodiments of this application.

[0065] Figure 2 This is a top view of the device provided in the embodiments of this application.

[0066] Figure 3 This is a side view of the device provided in the embodiments of this application.

[0067] Figure 4 This is a structural diagram of the movable triangular iron plate provided in the embodiments of this application.

[0068] The diagram is labeled as follows:

[0069] 1-Triangular main support, 2-Extension rod, 3-Modible triangular iron plate, 4-Scanning equipment connector, 5-First circular level, 6-First tripod, 7-Second tripod, 8-Third tripod, 9-First movable telescopic rod, 10-Second movable telescopic rod, 11-Third movable telescopic rod, 12-First rotating tensioner, 13-Second rotating tensioner, 14-Third rotating tensioner, 15-Fourth rotating tensioner, 16-First extension frame, 17-Second circular level, 18-Second extension frame, 19-Hinge, 20-First rectangular iron plate, 21-Second rectangular iron plate, 22-Third rectangular iron plate, 23-First crosshair target, 24-Second crosshair target, 25-Third crosshair target, 26-First bolt, 27-Second bolt, 28-Third bolt, 29-Slide groove, 30-Modible rectangular steel plate. Detailed Implementation

[0070] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0071] In the description of this invention, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0073] It should be noted that similar reference numerals and letters indicate similar items; therefore, once an item is defined in one embodiment, it does not need to be further defined and explained in subsequent embodiments. Furthermore, in the description of this invention, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. Of course, such objects can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in a sequence other than that illustrated or described herein.

[0074] This invention provides a three-dimensional laser scanning auxiliary device for rapidly deploying targets on-site and converting the coordinates of the carried three-dimensional laser scanner into geodetic coordinates to accurately acquire information about the target. Figure 1-4 The device mainly consists of three parts: a triangular main support 1, an extension rod 2, and a movable triangular iron plate 3.

[0075] The triangular main support 1 comprises three legs, interconnected at the top to form a tripod structure. Each leg has a sleeve structure at its bottom with lateral screw holes. A telescopic rod is inserted into the bottom of the sleeve structure, and then secured through the lateral screw holes using a rotating tensioner (a bolt). The first leg 6 has a first telescopic rod 9 and a first rotating tensioner 12 at its bottom; the second leg 7 has a second telescopic rod 10 and a second rotating tensioner 13 at its bottom; and the third leg 8 has a third telescopic rod 11 and a third rotating tensioner 14 at its bottom. After loosening the rotating tensioners, the telescopic rods can move up and down within the sleeve structure at the bottom of the legs, thereby adjusting the length of each leg. A scanning device connector 4 is located at the top of the triangular main support 1 for mounting a 3D laser scanner. Since the length of each leg is independently adjustable, the height and tilt angle of the 3D laser scanner can be changed by adjusting the three legs. The scanning device connector 4 is equipped with a first circular level 5. During adjustment, the bubble in the first circular level 5 must be centered.

[0076] The extension rod 2 comprises two sections: a first extension frame 16 and a second extension frame 18, which together form a telescopic rod structure. The extension rod 2 is horizontally positioned, with one end movably connected to the lower part of the triangular main support 1, and the other end equipped with a hinge 19 and connected to a movable rectangular steel plate 30. A three-dimensional electronic compass display is mounted on the outer side of the movable rectangular steel plate 30. The movable rectangular steel plate 30 can rotate up and down around the hinge 19 to change its tilt angle. One of the legs, such as the first leg 6, has a groove 29 arranged along its length on its inner side. The side of the groove 29 has screw holes. One end of the extension rod 2 is inserted into the groove 29 and installed to the inner side of the first leg 6 via a fourth rotary tensioner 15. After rotating the fourth rotary tensioner 15, one end of the extension rod 2 can move up and down within the groove, thereby adjusting the height of the extension rod 2. A second circular level 17 is mounted on the first extension frame 16; during adjustment, the bubble in the second circular level 17 must be centered.

[0077] The movable triangular iron plate 3 is an inverted equilateral triangle, with its bottom connected to the top of the movable rectangular steel plate 30. The movable triangular iron plate 3 comprises three rectangular iron plates connected end-to-end, each with a crosshair target at one of the three connection points: a first crosshair target 23, a second crosshair target 24, and a third crosshair target 25. The rectangular iron plates are a first rectangular iron plate 20, a second rectangular iron plate 21, and a third rectangular iron plate 22. The first rectangular iron plate 20 and the second rectangular iron plate 21 are connected to the ends of the movable rectangular steel plate 30 by a first bolt 26 and a nut. The third rectangular iron plate 22 is connected to the first rectangular iron plate 20 by a second bolt 27 and a nut, and the third rectangular iron plate 22 is connected to the second rectangular iron plate 21 by a third bolt 28 and a nut. The movable triangular iron plate 3 can rotate around the first bolt 26 in its plane and can be rotated up and down by the movable rectangular steel plate 30.

[0078] Because the movable triangular iron plate 3 with the crosshair target is located on the side of the main triangular support 1 and connected to the main triangular support 1 via the extension rod 2, it can extend and retract laterally. During installation, it can be moved away from the side to be targeted first, and then the crosshair target can be pushed to the side to be targeted via the extension rod 2, reducing the risk of operation. In addition, the end of the extension rod 2 can move up and down within the sliding groove 29 provided on the main triangular support 1. Adjusting the height of the extension rod 2 adjusts the height of the crosshair target at the same time, without affecting other components and eliminating the need for readjustment.

[0079] Based on the aforementioned 3D laser scanning auxiliary device, this invention provides a reference system rotation method that can convert the acquired coordinates of a 3D laser scanner into geodetic coordinates. Although the method steps are described below, in some cases they may be performed in a different order. The method specifically includes:

[0080] S1: Adjust the attitude of the device.

[0081] S101: Adjusting the main triangular support 1:

[0082] The length of the tripod and the tilt angle of the 3D laser scanner can be adjusted by moving the telescopic rod and rotating the tensioner.

[0083] The overall height and tilt angle of the device can also be adjusted by adjusting the angle between the tripods.

[0084] S102: Adjusting extension rod 2:

[0085] The height of the extension rod 2 is adjusted by the fourth rotary tensioner 15, and the length of the extension rod 2 is adjusted by the telescopic rod structure.

[0086] S103: Adjustable movable triangle plate 3:

[0087] The tilt angle of the movable rectangular steel plate 30 can be adjusted by the hinge 19, which in turn adjusts the tilt angle of the movable triangular iron plate 3. Additionally, the first bolt 26 can be used to adjust the rotation of the movable triangular iron plate 3 within its plane.

[0088] During the adjustment process, the movable triangle plate 3 is brought close to the surface being measured, and the bubbles of the first circular level 5 and the second circular level 17 are centered.

[0089] S2: Obtain point cloud data of the test surface and the cross-shaped target using a 3D laser scanner, and extract the point cloud coordinates P1(x1,y1,z1), P2(x2,y2,z2), and P3(x3,y3,z3) of the three cross-shaped targets from the point cloud data.

[0090] S3: Obtain the compass inclination α1 and compass tilt angle β1 of the movable triangular iron plate 3 through a three-dimensional electronic compass digital display.

[0091] S4: Determine the scanning tendency α2 and scanning tilt angle β2 of the movable triangular iron plate 3 based on P1, P2, and P3, including:

[0092] S401: Based on P1, P2, and P3, obtain the normal vector of the plane containing the crosshair target:

[0093]

[0094] S402: Let the normal vector be (a1, b1, c1), and calculate the scanning inclination α2 and scanning tilt angle β2 of the plane where the crosshair target is located, i.e., the movable triangular iron plate 3, based on the normal vector:

[0095]

[0096] When b1 > 0

[0097]

[0098] When b1≤0

[0099]

[0100] S5: Calculate the normal vector n1 between α1 and β1, and the normal vector n2 between α2 and β2, and then calculate the angle θ between n1 and n2 and the rotation axis vector (r). x r y r z ),include:

[0101] S501: Calculate n1 and n2:

[0102] n1=(n x1 n y1 nz1 )=(sinβ1cosα1 sinβ1sinα1 cosβ1);

[0103] n2=(n x2 n y2 n z2 )=(sinβ2cosα2 sinβ2sinα2 cosβ2);

[0104] S502: Calculate θ based on n1 and n2:

[0105] cosθ=(n x1 ×n x2 +n y1 ×n y2 +n z1 ×n z2 ) / (sqrt(n x1 2 +n y1 2 +n z1 2 )×sqrt(n x2 2 +n y2 2 +n z2 2 ));

[0106] S503: Calculate (r) based on the cross product of n1 and n2. x r y r z ):

[0107] r x =n y1 ×n z2 -n z1 ×n y2 ;

[0108] r y =n z1 ×n x2 -n x1 ×n z2 ;

[0109] r z =n x1 ×n y2 -n y1 ×n x2 .

[0110] S6: Based on θ and (r) x r y r z Calculate the rotation angles α, β, and γ along the z-axis, y-axis, and x-axis respectively, including:

[0111] α=arctan(r z / r y );

[0112]

[0113] γ=arctan(r x / r z ).

[0114] In the zyx order of Euler angles, the third value γ represents the angle of rotation about the x-axis; the second value β represents the angle of rotation about the y-axis after rotating about the z-axis by α; and the first value α represents the angle of rotation about the z-axis first.

[0115] S7: Combining θ with α, β, and γ yields the rotation matrix, including:

[0116] The rotation matrix along the z-axis is:

[0117]

[0118] The rotation matrix along the y-axis is:

[0119]

[0120] The rotation matrix along the x-axis is:

[0121]

[0122] S8: Convert the coordinates of the point cloud data into geodetic coordinates using a rotation matrix, including:

[0123] If the coordinates obtained by the 3D laser scanner are (x0, y0, z0);

[0124] Converted to geodetic coordinates:

[0125]

[0126] The present invention also provides a storage medium comprising a stored program that, when executed by a processor, performs the aforementioned computational process. The storage medium may be located in any computer terminal within a group of computer terminals in a computer network, or in any mobile terminal within a group of mobile terminals. The storage medium is configured to store program code for performing the aforementioned steps.

[0127] Those skilled in the art will understand that all or part of the functions of the method of the present invention can be implemented by hardware or by computer program. When all or part of the functions in the above embodiments are implemented by computer program, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the above functions are implemented by executing the program by a computer. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be implemented. In addition, when all or part of the functions in the above embodiments are implemented by computer program, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash drive, or portable hard drive, and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be implemented.

[0128] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A reference system rotation method for a three-dimensional laser scanning auxiliary device, characterized in that: The method is implemented based on a three-dimensional laser scanning auxiliary device, which includes a triangular main support (1), an extension rod (2), and a movable triangular iron plate (3). The top of the triangular main support (1) is provided with a scanning equipment connector (4) for mounting a three-dimensional laser scanner. The extension rod (2) is horizontally positioned, with one end movably connected to the lower part of the triangular main support (1), and the other end provided with a hinge (19) and connected to a movable rectangular steel plate (30). A three-dimensional laser scanner is provided on the outer side of the movable rectangular steel plate (30). The electronic compass displays digitally; the movable triangular iron plate (3) is an inverted equilateral triangle, the bottom of the movable triangular iron plate (3) is connected to the top of the movable rectangular steel plate (30), the movable triangular iron plate (3) includes three rectangular iron plates connected end to end, and a crosshair target is set at each of the three connection points; after the movable triangular iron plate (3) is close to the surface to be measured, the three-dimensional laser scanner is used to acquire the point cloud data of the surface to be measured and the crosshair target, and the three-dimensional electronic compass displays digitally are used to acquire the inclination of the movable triangular iron plate (3). and tilt angle The device also includes a first circular level (5) and a second circular level (17); the first circular level (5) is mounted on the scanning device connector (4); the second circular level (17) is mounted on the extension rod (2); The method includes: Adjust the height of the main triangular support (1), the height of the extension rod (2), and the tilt angle of the movable triangular iron plate (3) so that the movable triangular iron plate (3) is close to the surface being measured, and so that the bubbles of the first circular level (5) and the second circular level (17) are in a centered state. The point cloud data of the measured surface and the crosshair targets are acquired using the 3D laser scanner, and the point cloud coordinates of the three crosshair targets are extracted from the point cloud data. , , ; The compass inclination of the movable triangle plate (3) is obtained through the digital display of the three-dimensional electronic compass. With compass tilt ; according to , , Determine the scanning tendency of the movable triangular iron plate (3). With scanning tilt angle ; calculate and normal vector ,as well as and normal vector , and then calculate and The included angle and rotation axis vector ; according to and Calculate the rotation angles along the z-axis, y-axis, and x-axis respectively. ; Combination and Obtain the rotation matrix; The coordinates of the point cloud data are converted into geodetic coordinates using a rotation matrix. in: according to , , Determine the scanning tendency of the movable triangular iron plate (3). With scanning tilt angle ,include: according to , , Obtain the normal vector of the plane containing the crosshair target: ； Let the normal vector be The scanning tendency of the plane where the crosshair target is located, i.e., the movable triangular iron plate (3), is determined based on the normal vector. With scanning tilt angle : ； when hour, ； when hour, ； calculate and normal vector ,as well as and normal vector , and then calculate and The included angle and rotation axis vector ,include: calculate and : ； ； according to and calculate : ； according to and Cross product calculation : ； ； 。 2. The reference system rotation method of the three-dimensional laser scanning auxiliary device according to claim 1, characterized in that: The triangular main support (1) includes three legs, and the bottom end of the legs is connected to a movable telescopic rod via a rotating tensioner.

3. The reference system rotation method of the three-dimensional laser scanning auxiliary device according to claim 2, characterized in that: One of the legs has a groove (29) arranged along the length of the leg on its inner side, and one end of the extension rod (2) is installed into the groove (29) by a rotating tensioner.

4. The reference system rotation method of the three-dimensional laser scanning auxiliary device according to claim 3, characterized in that: according to and Calculate the rotation angles along the z-axis, y-axis, and x-axis respectively. ,include: ； ； 。 5. The reference system rotation method of the three-dimensional laser scanning auxiliary device according to claim 4, characterized in that: Combination and The rotation matrix is ​​obtained, including: The rotation matrix along the z-axis is: ； The rotation matrix along the y-axis is: ； The rotation matrix along the x-axis is: 。 6. The reference system rotation method of the three-dimensional laser scanning auxiliary device according to claim 5, characterized in that: The point cloud data coordinates are converted into geodetic coordinates using a rotation matrix, including: If the coordinates obtained by the 3D laser scanner are ; Converted to geodetic coordinates: 。

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