An automatically positioning and orienting laser scanning system and method

Abstract

The application discloses an automatic positioning and orienting laser scanning system and method, and the system comprises a robot total station, which has a long-distance communication function, is used for receiving a hand book device instruction, automatically searching a target prism, performing measurement, and converting measurement data into coordinates in an absolute coordinate system; a three-dimensional laser scanner, which comprises a WIFI communication module and is used for performing three-dimensional scanning on a target to be measured to generate point cloud data, and a 360-degree measurement prism is further arranged on the top of the three-dimensional laser scanner; and a hand book device, which comprises a WIFI communication module and is used for controlling the cooperative work of the robot total station and the three-dimensional laser scanner, including driving a measurement instruction to be issued, data to be received and analyzed. The application realizes efficient three-dimensional laser scanning.

Description

Technical Field

[0001] This invention relates to the field of laser measurement and point cloud generation application technology, specifically to an automatic positioning and orientation laser scanning system and method. Background Technology

[0002] 3D laser scanners utilize the principle of laser ranging to quickly reconstruct a 3D model and various graphic data such as lines, surfaces, and volumes of the target object by recording the 3D coordinates, reflectivity, and texture of a large number of dense points on the surface of the object being measured. 3D laser scanning systems can acquire a large number of data points of the target object densely; therefore, compared to traditional single-point measurement, 3D laser scanning technology is considered a technological breakthrough, evolving from single-point measurement to surface measurement. 3D laser scanning technology has also found numerous applications in fields such as cultural relic protection, architecture, planning, civil engineering, factory renovation, interior design, building monitoring, traffic accident handling, legal evidence collection, disaster assessment, ship design, digital cities, and military analysis. A 3D laser scanning system consists of hardware for data acquisition and software for data processing. Depending on the carrier, 3D laser scanning systems can be categorized into airborne, vehicle-mounted, ground-based, and handheld types. The entire system comprises a laser transmitter, receiver, time counter, motor-controlled rotatable filter, control circuit board, microcomputer, CCD sensor, and software.

[0003] A total station, also known as a total station electronic tachometer, is an instrument that, once observed at a station, automatically displays necessary data such as slope distance, zenith distance (vertical angle), and horizontal angle, and obtains horizontal distance, elevation difference, and point coordinates almost simultaneously. By connecting the data terminal of the total station's field data collection to a computer or plotter via a transmission interface, and using data processing and plotting software, automated mapping can be achieved. Total stations have become very mature and reliable after decades of development. Currently, total stations have evolved into a new generation of intelligent surveying total stations. These utilize a special camera that receives high-reflectivity light and a motor mounted on the total station body, driving the total station to rotate horizontally and vertically. When the camera detects a high-reflectivity target matching the set parameters, the rotation stops, and the measurement functions are activated to measure distance and angle, calculating the three-dimensional coordinates of the high-reflectivity target using distance and angle.

[0004] In conventional gantry scanner data processing, the common method is point cloud registration. Registration typically involves keypoint extraction methods such as PFP, PFHP, Span Image, and SHOT to extract feature points. Then, feature point matching and spatial rigidity invariance are used to register the point clouds of two stations, and the rotation and translation parameters between the two stations are calculated. However, point cloud registration methods have limitations. Because registration relies on matching feature points in the point cloud, in similar environments such as tunnels or indoor spaces, the lack of or similarity of features can easily lead to mismatches in the point clouds, resulting in registration failure. Therefore, in such advanced scenarios, point cloud scanning typically employs a target sphere stitching method. Specifically, at each station, at least three circular target spheres are placed in both the direction of travel and the opposite direction, ensuring that at least six target spheres can be identified and extracted from the point cloud at that station. Similarly, at the next station, at least three new circular target spheres will be placed in the direction of travel, while the target spheres in the opposite direction will remain unchanged, using the same target spheres and their positions from the previous station. This ensures that at least three target spheres in the same positions exist in each adjacent station. This method allows for stitching adjacent stations together using a traverse. However, this approach requires frequent placement of target spheres, resulting in a significant workload. Furthermore, since the target spheres lack coordinates, the registered point cloud remains a local coordinate system. Therefore, some current solutions use a prism sphere approach, replacing the target sphere mentioned above with a special target that is half prism and half target sphere. A total station can be used to measure each target sphere, thus converting the point cloud data from a station's relative coordinate system to the total station's absolute coordinate system based on the coordinates of the three target spheres. However, this requires manual measurement of the target spheres. Some solutions have also attempted to use robotic total stations to measure the target spheres, but in typical narrow areas, the increased distance between the target spheres and the robotic total station causes the robot to fail or stop searching for prisms due to a small field of view, preventing the robot from finding all the prisms. Therefore, a better method is needed to work under these conditions.

[0005] Chinese invention application No. 201410118157.4 discloses "A positioning device for a three-dimensional laser scanner and an absolute positioning method for laser point clouds". The device includes a positioning base for a three-dimensional laser scanner and two positioning prisms. The two positioning prisms are respectively set on both sides of the positioning base for the three-dimensional laser scanner through positioning prism connecting rods. The positioning prism connecting rods are fixed on the positioning base for the three-dimensional laser scanner, and the two positioning prisms are connected at both ends of the positioning prism connecting rods through screw threads. The method includes: Step 10: Fixing the 3D laser scanner on the 3D laser scanner positioning device, and collecting field data by combining the 3D laser scanner, the 3D laser scanner positioning device, and the total station, collecting the 3D point cloud of all measured objects and the total station feature points; Step 20: Importing the field data collected in Step 10 into a computer; Step 30: The data calculation module in the computer calculates the absolute position coordinates of the 3D point cloud of the measured object based on the 3D point cloud of the measured object and the total station feature points, and outputs it to the output module in the computer; Step 40: The output module in the computer outputs the positioned 3D laser point cloud data structure that is consistent with the coordinate system of the total station control measurement. The technical solution provided by this invention discloses a fixed prism positioning device and a 7-parameter coordinate transformation, but it does not solve the problem of point cloud direction deviation and relies on manual measurement with a total station. Summary of the Invention

[0006] To address the technical problems of existing 3D laser scanning systems, such as a large number of devices, high workflow complexity, slow search speed, and limited field of view, this invention provides an automatic positioning and orientation laser scanning system and method. The technical solution adopted by this invention is as follows:

[0007] The first aspect of the present invention provides an automatic positioning and orientation laser scanning system, the system comprising:

[0008] The robotic total station has long-distance communication capabilities, used to receive instructions from handheld devices, automatically search for target prisms, perform measurements, and convert measurement data into coordinates in an absolute coordinate system.

[0009] A 3D laser scanner, including a WIFI communication module, is used to perform 3D scanning of the target to generate point cloud data. The top of the 3D laser scanner is also equipped with a 360-degree measuring prism.

[0010] The handheld device, including a WIFI communication module, is used to control the collaborative operation of the robotic total station and the 3D laser scanner, including issuing driving measurement commands, receiving data, and parsing data.

[0011] As a preferred embodiment, the system also includes a dedicated communication protocol module integrated into the handheld device for sequentially sending the following instructions:

[0012] First command: Command to drive the 3D laser scanner to rotate by a preset angle;

[0013] Second instruction: Instruction to drive the robot total station to perform automatic target recognition;

[0014] Repeat the first instruction to the second instruction at least 4 times to obtain multiple sets of 360-degree measurement prism coordinates and corresponding encoder angle values.

[0015] As a preferred embodiment, the handheld device calculates the absolute coordinates of the optical axis center of the 3D laser scanner by fitting the coordinates of multiple measurement points of the 360-degree measuring prism.

[0016] As a preferred embodiment, the robotic total station also includes a built-in algorithm module for:

[0017] Based on the coordinates of at least four 360-degree measuring prism measurement points and the corresponding encoder angle values, fit the rotation plane and optical axis center coordinates of the 3D laser scanner;

[0018] The rotation matrix of the point cloud data is calculated by the angle deviation of the encoder, and the point cloud in the relative coordinate system is converted into the point cloud in the absolute coordinate system.

[0019] A second aspect of the present invention provides an automatic positioning and orientation laser scanning method, the method comprising:

[0020] Set up the robotic total station and level the ground. Determine the absolute coordinates and orientation of the total station using backsight orientation or resection method.

[0021] Place the 3D laser scanner near the object to be measured, ensuring that it is in line of sight to the total station;

[0022] The handheld device sends preset commands to the robot total station and 3D laser scanner via a dedicated protocol to perform measurements, and obtains multiple sets of data pairs, wherein the data pairs consist of the angle values ​​of the codebook and the coordinates of the 360-degree measuring prism on the top of the scanner.

[0023] Based on the data pair, fit the rotation plane of the 3D laser scanner and calculate the coordinates of the optical axis center;

[0024] The scanner's center direction is determined by the encoder angle deviation, and a rotation matrix is ​​generated. The relative coordinate system point cloud data collected by the scanner is then transformed to the absolute coordinate system using the rotation matrix and the center coordinates.

[0025] As a preferred embodiment, the method of using a handheld device to send preset commands to a robotic total station and a 3D laser scanner via a dedicated protocol to perform measurements and obtain multiple sets of data pairs includes:

[0026] a) Drive the 3D laser scanner to rotate by an angle less than 60 degrees and record the current encoder angle value V;

[0027] b) Drive the robot total station to measure the coordinates P of the prism at the top of the 3D laser scanner, which measures 360 degrees.

[0028] c) Repeat steps a)-b) at least 4 times to generate multiple sets of data pairs P1-V1, P2-V2, P3-V3, P4-V4, ..., P n -V n .

[0029] As a preferred embodiment, the method for calculating the coordinates of the optical axis center by fitting the rotation plane of the 3D laser scanner based on the data pair includes:

[0030] Data selection:

[0031] Select the coordinates of four 360-degree measuring prism measurement points, denoted as P1 ( x 1, y 1, z 1) P2 ( x 2, y 2, z 2) P3 ( x 3, y 3, z 3) P4 ( x 4, y 4, z 4);

[0032] Plane fitting:

[0033] Calculate the vector by selecting the coordinates of three 360-degree measuring prism measurement points. , The cross product yields the normal vector. ;

[0034] Generate the initial plane equation based on the normal vector. ;

[0035] Calculate the distance from the fourth point P4 to the plane. D , where; if the distance D If the value exceeds a preset threshold, the least squares method is used to optimize the plane equation.

[0036] Calculation of the center of the circle:

[0037] Project the four points P1, P2, P3, and P4 onto the fitting plane to convert them into a two-dimensional point set. to ;

[0038] Solve the equation of a circle Obtain the coordinates of the center of the circle. ;

[0039] The optical axis center offset is calculated based on the preset structural parameters of the 3D laser scanner; the three-dimensional coordinates of the optical axis center are calculated based on the calculated optical axis center offset; wherein the preset structural parameters include the height h1 of the 360-degree measuring prism and the height h2 from the center of the scanner optical axis to the top of the scanner, and h1+h2 is the light output center offset.

[0040] As a preferred embodiment, the scanner's center-of-motion orientation is determined by the encoder angle deviation, and a rotation matrix is ​​generated. The method for transforming the relative coordinate system point cloud data acquired by the scanner to an absolute coordinate system using the rotation matrix and the center-of-motion coordinates includes:

[0041] Based on the encoder angle values ​​V1, V2, V3, V4 and the fitting plane normal vector, calculate the angle between the 0-degree mark of the encoder and the XY plane of the absolute coordinate system. dV ;

[0042] According to the included angle dV The rotation matrix is ​​obtained, and then the rotation matrix is ​​converted from the point cloud into a relative coordinate system to an absolute coordinate system after being solved into a relative coordinate system.

[0043] As a preferred embodiment, the method for optimizing plane equations using the least squares method includes:

[0044] Assume the plane equation is:

[0045]

[0046] Convert the plane equation to point normal form:

[0047]

[0048] in, p , q , r All of these are parameters to be determined;

[0049] For each data point ( x i , y i , z i Its perpendicular distance to the plane is:

[0050]

[0051] Construct the objective function:

[0052]

[0053] in, n This indicates the number of measurement points involved in the plane fitting. iThe index number of the point;

[0054] The objective function aims to minimize the sum of squared errors at all points.

[0055] A third aspect of the present invention provides a computer device, including a storage medium, a processor, and a computer program stored in the storage medium and executable by the processor, wherein the computer program, when executed by the processor, implements the steps of the aforementioned automatic positioning and orientation laser scanning method.

[0056] Compared with the prior art, the beneficial effects of this invention are:

[0057] This invention uses a 360-degree measuring prism installed at any position, combined with a multi-point fitting algorithm, eliminating the need for physical alignment and significantly reducing setup time.

[0058] This invention uses handheld software to automatically drive the scanner to rotate and fit the optical axis center, replacing manual calibration, and is suitable for rapid deployment in complex terrains (such as tunnels and mines).

[0059] This invention calculates the rotation matrix by using the code disk angle deviation (dV), eliminating the problem of 180° direction reversal of point clouds in feature degradation scenarios (such as tunnels), and greatly improving the stitching success rate.

[0060] This invention significantly improves the accuracy of point cloud stitching by combining least-squares plane fitting with structural parameter correction. Attached Figure Description

[0061] Figure 1 This embodiment provides a connection diagram of an automatic positioning and orientation laser scanning system;

[0062] Figure 2 This embodiment provides a flowchart of an automatic positioning and orientation laser scanning method;

[0063] Explanation of reference numerals in the attached figures:

[0064] 1. Robotic total station; 2. 3D laser scanner; 21. 360-degree measuring prism; 3. Handheld device. Detailed Implementation

[0065] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention.

[0066] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0067] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0068] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0069] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. The invention will be further described below with reference to the accompanying drawings and embodiments.

[0070] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0071] Example 1

[0072] Please refer to Figure 1 This embodiment provides an automatic positioning and orientation laser scanning system, the system comprising:

[0073] The robot total station 1 has long-distance communication capabilities, which is used to receive instructions from the handheld device 3, automatically search for the target prism, perform measurements, and convert the measurement data into coordinates in the absolute coordinate system;

[0074] The 3D laser scanner 2 includes a WIFI communication module for performing 3D scanning of the target to generate point cloud data. The top of the 3D laser scanner 2 is also equipped with a 360-degree measuring prism 21.

[0075] The handheld device 3 includes a WIFI communication module, which is used to control the collaborative work of the robot total station 1 and the 3D laser scanner 2, including issuing driving measurement commands, receiving data and parsing data.

[0076] In one specific embodiment, the system further includes a dedicated communication protocol module integrated into the handheld device 3, for sending the following instructions in sequence:

[0077] First command: The command to drive the 3D laser scanner 2 to rotate by a preset angle: _startScanRotate;

[0078] Second command: Drive the robot total station 1 to execute the automatic target recognition command _startATR;

[0079] Repeat the first instruction to the second instruction at least 4 times to obtain multiple sets of coordinates of the 360-degree measuring prism 21 and the corresponding encoder angle values.

[0080] In one specific embodiment, the handheld device 3 calculates the absolute coordinates of the optical axis center of the three-dimensional laser scanner 2 by fitting the coordinates of multiple measurement points of the 360-degree measuring prism 21.

[0081] In one specific embodiment, the robotic total station 1 further includes a built-in algorithm module for:

[0082] Based on the coordinates of the measurement points of at least four 360-degree measuring prisms 21 and the corresponding encoder angle values, fit the rotation plane and optical axis center coordinates of the three-dimensional laser scanner 2.

[0083] The rotation matrix of the point cloud data is calculated by the angle deviation of the encoder, and the point cloud in the relative coordinate system is converted into the point cloud in the absolute coordinate system.

[0084] Specifically, the typical workflow of the system is as follows:

[0085] 1. Set up the robot total station 1 and level it; whether it is centered depends on whether the robot total station 1 is set up on a known point.

[0086] 2. The robot total station 1 is set up, and the coordinates and orientation of the current position of the robot total station 1 are measured by backsight orientation or resection.

[0087] 3. The 3D laser scanner 2 is placed near the object to be scanned, and the 3D laser scanner 2 and the robot total station 1 are kept in line of sight.

[0088] 4. The handheld device 3 is connected to the robot total station 1 and the 3D laser scanner 2 respectively.

[0089] 5. The handheld software drives the robot total station 1 to observe and record the coordinates of the 360-degree measuring prism 21 on top of the 3D laser scanner 2.

[0090] 6. The handheld software drives the 3D laser scanner 2 to perform scanning operations.

[0091] 7. The above constitutes one station of scanning. After completion, the 3D laser scanner 2 is moved to the next station, and steps 5-6 are repeated for measurement.

[0092] 8. When the distance between the 3D laser scanner 2 and the robot total station 1 reaches a certain level, or when they are no longer in line of sight, the robot total station 1 needs to be moved. At this time, steps 1-6 need to be repeated.

[0093] Example 2

[0094] Please refer to Figure 2 This embodiment provides an automatic positioning and orientation laser scanning method, the method comprising:

[0095] S1: Set up the robotic total station and level the ground. Determine the absolute coordinates and orientation of the total station using backsight orientation or resection method.

[0096] S2: Place the 3D laser scanner near the object to be measured, ensuring that it is in line of sight to the total station;

[0097] S3: Using a handheld device, preset commands are sent to the robot total station and 3D laser scanner via a dedicated protocol to perform measurements and obtain multiple sets of data pairs, wherein the data pairs consist of the angle values ​​of the codebook and the coordinates of the 360-degree measuring prism on the top of the scanner;

[0098] In one specific embodiment, the method of using a handheld device to send preset commands to a robotic total station and a 3D laser scanner via a dedicated protocol to perform measurements and obtain multiple sets of data pairs includes:

[0099] a) Drive the 3D laser scanner to rotate by an angle less than 60 degrees and record the current encoder angle value V;

[0100] b) Drive the robot total station to measure the coordinates P of the 360-degree measuring prism on the top of the 3D laser scanner;

[0101] c) Repeat steps a)-b) at least 4 times to generate multiple sets of data pairs P1-V1, P2-V2, P3-V3, P4-V4, ..., P n -V n .

[0102] S4: Based on the data pair, fit the rotation plane of the 3D laser scanner and calculate the coordinates of the optical axis center;

[0103] In one specific embodiment, the method for calculating the coordinates of the optical axis center by fitting the rotation plane of a 3D laser scanner based on the data pair includes:

[0104] Data selection:

[0105] Select the coordinates of four measurement points for the 360-degree measuring prism, denoted as P1 ( x 1, y 1, z 1) P2 ( x 2, y 2, z 2) P3 ( x 3, y 3, z 3) P4 ( x 4, y 4, z 4);

[0106] Plane fitting:

[0107] Calculate the vector by selecting the coordinates of the measurement points of three 360-degree measuring prisms. , The cross product yields the normal vector. ;

[0108] Generate the initial plane equation based on the normal vector. ;

[0109] Calculate the distance from the fourth point P4 to the plane. D , where; if the distance D If the value exceeds a preset threshold, the least squares method is used to optimize the plane equation.

[0110] Calculation of the center of the circle:

[0111] Project the four points P1, P2, P3, and P4 onto the fitting plane to convert them into a two-dimensional point set. to ;

[0112] Solve the equation of a circle Obtain the coordinates of the center of the circle. ;

[0113] The optical axis center offset is calculated based on the preset structural parameters of the 3D laser scanner; the three-dimensional coordinates of the optical axis center are calculated based on the calculated optical axis center offset; wherein the preset structural parameters include the height h1 of the 360-degree measuring prism and the height h2 from the center of the scanner optical axis to the top of the scanner, and h1+h2 is the light output center offset.

[0114] In one specific embodiment, the method for optimizing plane equations using the least squares method includes:

[0115] Assume the plane equation is:

[0116]

[0117] Convert the plane equation to point normal form:

[0118]

[0119] in, p , q , r All of these are parameters to be determined;

[0120] For each data point ( x i , y i , z i Its perpendicular distance to the plane is:

[0121]

[0122] Construct the objective function:

[0123]

[0124] in, n This indicates the number of measurement points involved in the plane fitting. i The index number of the point;

[0125] The objective function aims to minimize the sum of squared errors at all points.

[0126] S5: Determine the scanner's center direction by the code disk angle deviation and generate a rotation matrix; transform the relative coordinate system point cloud data collected by the scanner to the absolute coordinate system using the rotation matrix and the center coordinates;

[0127] In one specific embodiment, the scanner's center-of-motion orientation is determined by the encoder angle deviation, and a rotation matrix is ​​generated. The method for transforming the relative coordinate system point cloud data acquired by the scanner to an absolute coordinate system using the rotation matrix and the center-of-motion coordinates includes:

[0128] Based on the encoder angle values ​​V1, V2, V3, V4 and the fitting plane normal vector, calculate the angle between the 0-degree mark of the encoder and the XY plane of the absolute coordinate system. dV Specifically:

[0129] Calculate the vector from the center of the circle to the measurement point:

[0130] Given the coordinates of the fitted circle center P0 and four measurement points P1, P2, P3, and P4, calculate the vector:

[0131]

[0132] in, i =1,2,3,4.

[0133] Calculate the angle between adjacent vectors:

[0134] vector and The included angle Equal to the difference in encoder angle:

[0135]

[0136] in, and For adjacent vectors, j =1,2,3,4, and i ≠ j ; V i , V j This refers to the encoder angle value returned by the scanner.

[0137] Construct a local coordinate system:

[0138] X-axis (unit vector) ):

[0139] Pick Direction:

[0140]

[0141] Y-axis (unit vector) ):

[0142] calculate exist Projection on the vertical plane:

[0143] Unitization:

[0144]

[0145] Calculate the angle of the 0-degree direction of the code disk in the local coordinate system:

[0146] Vector corresponding to the 0-degree direction of the code disk The coordinates in the local coordinate system are:

[0147]

[0148] in ϕ The angle to be determined.

[0149] Based on geometric relationships: when the encoder angle VWhen =0, its direction is the same as The included angle is V 1 (i.e.) ϕ =− V 1).

[0150] Solving for angle deviation dV :

[0151] dV It is the angle between the 0-degree direction of the code disk and the X-axis of the absolute coordinate system, calculated through the following steps:

[0152] Extracting the absolute coordinate system reference direction:

[0153] Take the unit vector of the X-axis in the absolute coordinate system. ;

[0154] Projected onto the fitted plane:

[0155] Will Projected onto the fitting plane (normal vector is ):

[0156]

[0157] Calculate the angle of the projection vector in the local coordinate system:

[0158]

[0159] Final angle deviation:

[0160]

[0161] According to the included angle dV The rotation matrix is ​​obtained, and then the rotation matrix is ​​converted from the point cloud into a relative coordinate system to an absolute coordinate system after being solved into a relative coordinate system.

[0162] Example 3

[0163] This embodiment provides a computer device, including a storage medium, a processor, and a computer program stored in the storage medium and executable by the processor. When the computer program is executed by the processor, it implements the steps of the automatic positioning and orientation laser scanning method described in Embodiment 2.

[0164] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An automatic positioning and orientation laser scanning system, characterized in that, The system includes: The robot total station (1) has long-distance communication capabilities, which is used to receive instructions from handheld devices, automatically search for target prisms, perform measurements, and convert measurement data into coordinates in an absolute coordinate system. The three-dimensional laser scanner (2) includes a WIFI communication module for performing three-dimensional scanning of the target to generate point cloud data. The top of the three-dimensional laser scanner (2) is also provided with a 360-degree measuring prism (21). The handheld device (3) includes a WIFI communication module for controlling the collaborative work of the robot total station (1) and the three-dimensional laser scanner (2), including driving the issuance of measurement commands, receiving and parsing data; The handheld device (3) calculates the absolute coordinates of the optical axis center of the three-dimensional laser scanner (2) by fitting the coordinates of multiple measurement points of the 360-degree measuring prism (21); The robotic total station (1) also includes a built-in algorithm module for: Based on the coordinates of the measurement points of at least four 360-degree measuring prisms (21) and the corresponding encoder angle values, fit the rotation plane and optical axis center coordinates of the three-dimensional laser scanner (2); The rotation matrix of the point cloud data is calculated by the angle deviation of the encoder, and the point cloud in the relative coordinate system is converted into the point cloud in the absolute coordinate system. Methods for fitting the rotation plane of a 3D laser scanner and calculating the coordinates of the optical axis center include: Data selection: Select the coordinates of four measurement points for the 360-degree measuring prism, denoted as P1 ( x 1, y 1, z 1) P2 ( x 2, y 2, z 2) P3 ( x 3, y 3, z 3) P4 ( x 4, y 4, z 4); Plane fitting: Calculate the vector by selecting the coordinates of the measurement points of three 360-degree measuring prisms. , The cross product yields the normal vector. ; Generate the initial plane equation based on the normal vector. ; Calculate the distance from the fourth point P4 to the plane. D , where; if the distance D If the value exceeds a preset threshold, the least squares method is used to optimize the plane equation. Calculation of the center of the circle: Project the four points P1, P2, P3, and P4 onto the fitting plane to convert them into a two-dimensional point set. to ; Solve the equation of a circle The coordinates of the center of the circle, P0, are obtained. ; The optical axis center offset is calculated based on the preset structural parameters of the 3D laser scanner; the three-dimensional coordinates of the optical axis center are calculated based on the calculated optical axis center offset; wherein the preset structural parameters include the height h1 of the 360-degree measuring prism and the height h2 from the optical axis center of the 3D laser scanner to the top of the 3D laser scanner, and h1+h2 is the light output center offset.

2. The automatic positioning and orientation laser scanning system according to claim 1, characterized in that, The system also includes a dedicated communication protocol module integrated into the handheld device (3) for sequentially sending the following instructions: First instruction: Instruction to drive the 3D laser scanner (2) to rotate by a preset angle; Second instruction: Drive the robot total station (1) to execute the instruction for automatic target recognition; Repeat the first instruction to the second instruction at least 4 times to obtain multiple sets of 360-degree measurement prism coordinates and corresponding encoder angle values.

3. A laser scanning method for automatic positioning and orientation, characterized in that, The method includes: Set up the robot total station and level the ground. Determine the absolute coordinates and orientation of the robot total station using backsight orientation or resection method. Place the 3D laser scanner near the object to be measured, ensuring that it is in line of sight to the robot total station; The handheld device sends preset commands to the robot total station and 3D laser scanner through a dedicated protocol to perform measurements, and obtains multiple sets of data pairs, wherein the data pairs consist of the angle values ​​of the codebook and the coordinates of the 360-degree measuring prism on the top of the 3D laser scanner; Based on the data pair, fit the rotation plane of the 3D laser scanner and calculate the coordinates of the optical axis center; The orientation of the 3D laser scanner's center is determined by the angle deviation of the encoder disk, and a rotation matrix is ​​generated. The point cloud data in the relative coordinate system collected by the 3D laser scanner is then transformed to the absolute coordinate system using the rotation matrix and the center coordinates. The method for fitting the rotation plane of a 3D laser scanner and calculating the coordinates of the optical axis center based on the data pair includes: Data selection: Select the coordinates of four measurement points for the 360-degree measuring prism, denoted as P1 ( x 1, y 1, z 1) P2 ( x 2, y 2, z 2) P3 ( x 3, y 3, z 3) P4 ( x 4, y 4, z 4); Plane fitting: Calculate the vector by selecting the coordinates of the measurement points of three 360-degree measuring prisms. , The cross product yields the normal vector. ; Generate the initial plane equation based on the normal vector. ; Calculate the distance from the fourth point P4 to the plane. D , where; if the distance D If the value exceeds a preset threshold, the least squares method is used to optimize the plane equation. Calculation of the center of the circle: Project the four points P1, P2, P3, and P4 onto the fitting plane to convert them into a two-dimensional point set. to ; Solve the equation of a circle The coordinates of the center of the circle, P0, are obtained. ; The optical axis center offset is calculated based on the preset structural parameters of the 3D laser scanner; the three-dimensional coordinates of the optical axis center are calculated based on the calculated optical axis center offset; wherein the preset structural parameters include the height h1 of the 360-degree measuring prism and the height h2 from the optical axis center of the 3D laser scanner to the top of the 3D laser scanner, and h1+h2 is the light output center offset.

4. The automatic positioning and orientation laser scanning method according to claim 3, characterized in that, The method of using a handheld device to send preset commands to a robotic total station and a 3D laser scanner via a dedicated protocol to perform measurements and obtain multiple sets of data pairs includes: a) Drive the 3D laser scanner to rotate by an angle less than 60 degrees and record the current encoder angle value V; b) Drive the robot total station to measure the coordinates P of the 360-degree measuring prism on the top of the 3D laser scanner; c) Repeat steps a)-b) at least 4 times to generate multiple sets of data pairs P1-V1, P2-V2, P3-V3, P4-V4, ..., P n -V n .

5. The automatic positioning and orientation laser scanning method according to claim 4, characterized in that, The orientation of the 3D laser scanner's center of gravity is determined by the angle deviation of the encoder disk, and a rotation matrix is ​​generated. The method for transforming relative coordinate system point cloud data acquired by a 3D laser scanner to an absolute coordinate system using the aforementioned rotation matrix and station center coordinates includes: Based on the encoder angle values ​​V1, V2, V3, V4 and the fitting plane normal vector, calculate the angle between the 0-degree mark of the encoder and the XY plane of the absolute coordinate system. dV ; According to the included angle dV The rotation matrix is ​​obtained, and then the rotation matrix is ​​converted from the point cloud into a relative coordinate system to an absolute coordinate system after being solved into a relative coordinate system.

6. The automatic positioning and orientation laser scanning method according to claim 5, characterized in that, The method for optimizing plane equations using the least squares method includes: Assume the plane equation is: Convert the plane equation to point normal form: in, p , q , r All of these are parameters to be determined; For each data point ( x i , y i , z i Its perpendicular distance to the plane is: Construct the objective function: in, n This indicates the number of measurement points involved in the plane fitting. i The index number of the point; The objective function aims to minimize the sum of squared errors at all points.

7. A computer device, characterized in that: It includes a storage medium, a processor, and a computer program stored in the storage medium and executable by the processor, wherein the computer program, when executed by the processor, implements the steps of an automatic positioning and orientation laser scanning method as described in any one of claims 3 to 6.

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