Three-dimensional laser scanner data acquisition method and system
By using the equidistant acquisition method and employing contour pre-scanning and iterative transition interpolation calculation, the problems of uneven data and low efficiency in traditional 3D laser scanner data acquisition methods are solved. This achieves uniform and precise data acquisition, improves scanning efficiency and accuracy, and reduces instrument damage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 肖厚藻
- Filing Date
- 2026-04-14
- Publication Date
- 2026-05-12
AI Technical Summary
Traditional 3D laser scanner data acquisition methods result in overly dense data acquisition at near distances and overly sparse data acquisition at distant distances. Furthermore, existing adaptive methods are inefficient and cause severe damage to the instrument, failing to meet practical needs.
The equidistant acquisition method is adopted. The region to be measured is pre-scanned Np times, the longest contour line is selected as the reference, the radial angle is evenly divided according to the expected scanning interval, and the axial rotation angle is calculated by iterative transition interpolation to achieve uniform and fine data acquisition.
It achieves uniform and precise acquisition of data points, improves scanning efficiency, avoids blind operation, meets scanning accuracy requirements, and reduces instrument damage.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of laser scanning, and more specifically to a data acquisition method and system for a three-dimensional laser scanner. Background Technology
[0002] A 3D laser scanner is a novel 3D coordinate measuring instrument integrating multiple high technologies. It employs a non-contact, high-speed laser measurement method to acquire 3D data of an array of geometric patterns on the surface of the object being measured, in the form of a point cloud. While the basic principle of laser ranging is well-developed, ensuring the accuracy and effectiveness of data acquisition, its data acquisition methods still warrant further discussion. Traditional data acquisition methods—such as the isometric acquisition method—are still relevant. Figure 1 , 2 As shown, the scanning head's radial oscillation and axial rotation are controlled by two stepper motors. The scanning head first rotates uniformly axially at a preset radial angle, acquiring one data point per rotation (usually a fixed value between 0.5° and 3°). After completing one full scan, the scanning head automatically oscillates (usually raises) by a preset angle (usually a fixed value between 1° and 5°) and continues the next scan until the entire scanning process is complete. This data acquisition method, where both the radial oscillation angle and the axial rotation angle are fixed values for each rotation, results in overly dense data acquisition at close range and overly sparse data acquisition at distant ranges.
[0003] Based on traditional data acquisition methods, the Beijing General Research Institute of Mining and Metallurgy has proposed an adaptive data acquisition method. During the scanning process, a pre-scan of the next scanning point is performed. Based on the scanning results, the radial oscillation angle θ and the axial rotation angle α are adjusted. Then, the next point is scanned based on the adjusted θ' and α'. The principle is as follows: Figure 3 As shown, this method plays a certain role in improving the precision and uniformity of data acquisition. However, it requires both the stepper motor controlling the radial oscillation and the stepper motor controlling the axial rotation to operate back and forth continuously. Furthermore, the contours shown in the figure do not actually exist, leading to significant uncertainty. This method not only greatly reduces the efficiency of data acquisition but also causes severe damage to the instrument, failing to meet practical needs.
[0004] No one abroad has yet researched data acquisition methods for 3D laser scanners, so there is an urgent need for an efficient and practical data acquisition method for 3D laser scanners. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a three-dimensional laser scanner data acquisition method and system that can obtain uniform and fine data acquisition points that meet the expected scanning spacing as much as possible.
[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a data acquisition method for a three-dimensional laser scanner—an equidistant acquisition method, comprising: N p Sub-contour pre-scan (N) p ≥1 (set by the user based on the complexity of the area to be tested). Based on the pre-scan results, 2*N is obtained. p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. The baseline contour is evenly divided according to the expected scanning interval Tol (Tol>0, set by the user according to requirements), thereby calculating the angle θ of the scanning head's radial swing for each time. i ; In the radial angle θ i The angle α of the scanning head's axial rotation is obtained by iterative transition interpolation between each contour line and the next contour line. i,j ; According to each radial swing angle θ i and the axial rotation angle α under that radial angle i,j Laser scanning is performed to obtain three-dimensional spatial data points of the area to be measured.
[0007] In this process, the baseline contour line is evenly divided according to the expected scanning interval Tol (Tol>0, set by the user according to requirements), thereby calculating the angle θ of each radial swing of the scanning head. i .
[0008] The angle θ of the scanning head's radial oscillation each time i Calculate as follows: θ i =Θ i -Θ i-1 =arcsin(R n,i / S n,i )-arcsin(R n,i-1 / S n,i-1 ) In the formula, Θ i R is the angle between the ray emitted after the i-th radial swing of the scanning head and the initial azimuth line (i≥1, Θ0=0); n,i S is the perpendicular distance from the point where the ray emitted after the i-th radial oscillation of the scanning head intersects the reference contour line to the initial azimuth line (n=1, indicating that the ray emitted by the scanning head intersects the reference contour line); n,i The distance from the laser scanning head to the point where the ray emitted after the i-th radial oscillation of the scanning head intersects with the reference contour line (n=1, indicating that the ray emitted by the scanning head intersects with the reference contour line).
[0009] Wherein, at the radial angle θ i The angle α of the scanning head's axial rotation is obtained by iterative transition interpolation between each contour line and the next contour line. i,j .
[0010] The angle α of each rotation of the scanning head axis i,j Calculate as follows: α i,j =Tol×360 / (2π×r n,i,m ) In the formula, Tol is the expected scan spacing; R n,i The perpendicular distance from the point where the ray emitted after the i-th radial oscillation of the scanning head intersects the reference contour line to the initial azimuth line (n≥1, indicating that the ray emitted by the scanning head intersects the n-th contour line); r n,i,m For R n,i With R n+1,i The distance value obtained by the m-th iteration transition interpolation (n≥1, indicating that the ray emitted by the scan head intersects with the n-th contour line).
[0011] Secondly, the present invention provides a three-dimensional laser scanner data acquisition system, comprising: The information setting unit is used to set the spatial orientation information of the scanning head, including the spatial coordinates of the scanning head, the azimuth and tilt angles at the initial position, and the radial range of the scanning head; The pre-scanning unit is used to facilitate users in setting up a pre-scanning scheme according to the complexity of the area to be tested. The selection unit is used to obtain 2*N based on the pre-scan results. p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. The calculation unit is used to calculate each radial oscillation angle θ. i and the axial rotation angle α under that radial angle i,j ; Equidistant scanning units are used to sequentially scan according to each radial swing angle θ. i and the axial rotation angle α under that radial angle i,j Laser scanning is performed to obtain three-dimensional spatial data points of the area to be measured.
[0012] As described above, the 3D laser scanner data acquisition method and system of this invention can obtain uniform and precise data acquisition points that meet the expected scanning interval as much as possible, thus achieving equidistant acquisition. This solves the problem of uneven data points obtained by traditional data acquisition methods and also meets the accuracy requirements of data acquisition personnel, avoiding blind data acquisition. Attached Figure Description
[0013] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 , 2 A schematic diagram illustrating the principle of the conventional data acquisition method for 3D laser scanners—the isometric acquisition method; Figure 3 A schematic diagram of the adaptive data acquisition method for a 3D laser scanner proposed by the Beijing General Research Institute of Mining and Metallurgy is shown. Figure 4 A flowchart of a three-dimensional laser scanner data acquisition method provided in an embodiment of the present invention is shown; Figure 5 A schematic diagram of the equidistant acquisition method for a three-dimensional laser scanner provided in an embodiment of the present invention is shown. Figure 6 This diagram illustrates an iterative transition interpolation method involved in the three-dimensional laser scanner data acquisition method provided in an embodiment of the present invention. Figure 7 A schematic diagram of the interactive interface of the three-dimensional laser scanner data acquisition system provided in an embodiment of the present invention is shown. Figure 8 This diagram illustrates point data obtained using traditional data acquisition methods. Figure 9 This diagram illustrates point data obtained by the data acquisition method according to an embodiment of the present invention. Figure 10 A schematic diagram illustrating the modeling results of traditionally collected data is shown. Figure 11 A schematic diagram showing the modeling results of the collected data in an embodiment of the present invention is shown; Figure 12 A schematic diagram of the structure of the three-dimensional laser scanner data acquisition system provided in an embodiment of the present invention is shown. Detailed Implementation
[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example
[0016] Figure 4 A flowchart of a three-dimensional laser scanner data acquisition method according to Embodiment 1 of the present invention is shown. The three-dimensional laser scanner data acquisition method described in Embodiment 1 includes: Step 101: Perform N on the area to be tested. p Sub-contour pre-scan (N) p ≥1 (set by the user based on the complexity of the area to be tested). Step 102: Obtain 2*N based on the pre-scan results p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. Step 103: Divide the baseline contour line evenly according to the expected scanning interval Tol (Tol>0, set by the user according to requirements), thereby calculating the angle θ of the scanning head's radial swing for each time. i ; In this step, the radial angle θ of the scanning head oscillation i Calculate as follows: θ i =Θ i -Θ i-1 =arcsin(R n,i / S n,i )-arcsin(R n,i-1 / S n,i-1 ) In the formula, Θ i R is the angle between the ray emitted after the i-th radial swing of the scanning head and the initial azimuth line (i≥1, Θ0=0); n,i S is the perpendicular distance from the point where the ray emitted after the i-th radial oscillation of the scanning head intersects the reference contour line to the initial azimuth line (n=1, indicating that the ray emitted by the scanning head intersects the reference contour line); n,i The distance from the laser scanning head to the point where the ray emitted after the i-th radial oscillation of the scanning head intersects with the reference contour line (n=1, indicating that the ray emitted by the scanning head intersects with the reference contour line). Step 104: At the radial angle θ i The angle α of the scanning head's axial rotation is obtained by iterative transition interpolation between each contour line and the next contour line. i,j ; In this step, the scanning head rotates axially by an angle α. i,j Calculate as follows: α i,j =Tol×360 / (2π×r n,i,m ) In the formula, Tol is the expected scan spacing; R n,iThe perpendicular distance from the point where the ray emitted after the i-th radial oscillation of the scanning head intersects the reference contour line to the initial azimuth line (n≥1, indicating that the ray emitted by the scanning head intersects the n-th contour line); r n,i,m For R n,i With R n+1,i The distance value obtained by the m-th iteration transition interpolation (n≥1, indicating that the ray emitted by the scan head intersects with the n-th contour line).
[0017] Step 105: Sequentially adjust the radial oscillation angles θ i and the axial rotation angle α under that radial angle i,j Laser scanning is performed to obtain three-dimensional spatial data points of the area to be measured.
[0018] like Figure 5 As shown, two preliminary scans are performed to obtain approximate information of two cross-sections of the area to be measured. At the intersection, each scan result is divided into two parts, thus obtaining four contour lines of the area to be measured. The lengths of the four contour lines are calculated, and the longest contour line is selected as the reference contour line. The reference contour line is numbered 1, and the remaining contour lines are numbered 2, 3, and 4 in a counterclockwise direction. The next contour line after the fourth contour line is designated as the reference contour line.
[0019] Divide the baseline profile into equal parts according to the expected scanning interval Tol. The thickened part of the baseline profile in the figure is the i-th part after the equal division. The angle θ of the i-th swing of the scanning head can be calculated accordingly. i ; at radial angle θ i The angle α of the scanning head's axial rotation is obtained by iterative transition interpolation between each contour line and the next contour line. i,j .
[0020] like Figure 6 As shown, the angle of rotation of the scanning head axis is obtained by iterative interpolation between each contour line and the next contour line. Initial r n,i,0 =R n,i By controlling r n,i,0 The distance of rotation is equal to Tol, from which α is calculated. i,0 At this time r n,i,0 Iteration for r n,i,1 The α values are obtained by iterative transition interpolation. i,j until r n,i,m With R n+1,i The iteration terminates when the distance of rotation between them is less than Tol.
[0021] The three-dimensional laser scanner data acquisition method provided in this embodiment of the invention first completes the approximate contour scan of the area to be measured according to a preset scanning scheme (this process is called radial priority pre-scanning); secondly, the pre-scanning data is analyzed to calculate the working instructions for controlling the scanner to perform uniform and fine scanning (i.e., obtaining the angle of radial swing and the angle of axial rotation for each time), ensuring that the acquired data is uniform and fine (this process is called axial priority fine uniform scanning).
[0022] like Figure 7 As shown, in practical use, first, specify the spatial orientation information of the scanning head, including the spatial coordinates of the scanning head and the azimuth and tilt angles of the initial position; second, set the radial range according to the instrument's performance; set the radial priority pre-scan scheme (0° angle indicates a horizontal pre-scan to obtain approximate horizontal profile information, 90° angle indicates a longitudinal pre-scan to obtain approximate vertical profile information, and any angle pre-scan scheme can be set), and start the "Start Radial Priority Pre-Scan" button to obtain several profile information; divide each profile through the intersection point to obtain the contour line of the area to be measured, and select the longest contour line as the reference contour line. Then, set the tolerance of the axial priority uniform scan, i.e., the expected scanning interval, and start the "Start Axial Priority Uniform Scan" button, i.e., obtain the different angles θ of each oscillation of the scanning head. i and at each radial angle θ i Below, the axial rotation angle α of the scanning head i,j Finally, according to each radial angle θ i and the corresponding axial rotation angle α i,j Perform a scan to obtain uniform and detailed data acquisition results.
[0023] This method is applied to three-dimensional laser scanning of goaf areas in underground mines. Figure 8 For point data obtained using traditional data acquisition methods, Figure 9 This refers to data point information obtained using the data acquisition method provided by this invention. Figure 10 and Figure 11 The images show the reconstruction results of underground mining voids obtained from point data collected using different methods.
[0024] The 3D laser scanner data acquisition method described in this invention allows for the input of the desired spacing between each data point. By sequentially employing a radial-priority pre-scanning and an axial-priority uniform scanning scheme, uniform and precise data acquisition points that closely match the desired spacing are obtained. This solves the problem of uneven data points obtained by traditional data acquisition methods and also fulfills the data acquisition personnel's expectation of achieving a certain level of accuracy in the scan results, avoiding blind data acquisition.
[0025] This invention improves scanning results while ensuring scanning efficiency, and also avoids blind scanning.
[0026] Example 2 Figure 12 A schematic diagram of the structure of a three-dimensional laser scanner data acquisition system provided in Embodiment 2 of the present invention is shown. The three-dimensional laser scanner data acquisition system described in Embodiment 2 of the present invention includes: The information setting unit 91 is used to set the spatial orientation information of the scanning head, including the spatial coordinates of the scanning head, the azimuth and tilt angles at the initial position, and the radial range of the scanning head; The pre-scanning unit 92 is used to facilitate users in setting a pre-scanning scheme according to the complexity of the area to be tested. Selection unit 93 is used to obtain 2*N based on the pre-scan results. p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. Calculation unit 94 is used to calculate each radial oscillation angle θ. i and the axial rotation angle α under that radial angle i,j ; Equidistant scanning unit 95 is used to sequentially scan according to each radial swing angle θ i and the axial rotation angle α under that radial angle i,j Laser scanning is performed to obtain three-dimensional spatial data points of the area to be measured.
[0027] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A data acquisition method for a three-dimensional laser scanner—the equidistant acquisition method, characterized in that, include: N p Sub-contour pre-scan (N) p ≥1 (set by the user based on the complexity of the area to be tested). Based on the pre-scan results, 2*N is obtained. p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. The baseline contour is evenly divided according to the expected scanning interval Tol (Tol>0, set by the user according to requirements), thereby calculating the angle θ of the scanning head's radial swing for each time. i ; In the radial angle θ i The angle α of the scanning head's axial rotation is obtained by iterative transition interpolation between each contour line and the next contour line. i,j ; According to each radial swing angle θ i and the axial rotation angle α under that radial angle i,j Laser scanning is performed to obtain three-dimensional spatial data points of the area to be measured.
2. The method according to claim 1, characterized in that, Through N p The pre-scan results in 2*N p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. Where N... p The results of the pre-scan intersect the initial azimuth line at the same point. This intersection point divides each scan result into two parts, thus obtaining 2*N. p The outline of the area to be measured; calculate 2*N p Calculate the lengths of the contour lines and select the longest one as the baseline contour line; number the baseline contour line 1, and number the remaining contour lines 2, 3, ..., 2*N in a counter-clockwise direction. p The 2nd*Nth p The next contour line after the first contour line is the reference contour line.
3. The method according to claim 1, characterized in that, The baseline contour is evenly divided according to the expected scanning interval Tol (Tol>0, set by the user according to requirements), thereby calculating the angle θ of the scanning head's radial swing for each time. i Among them, the angle θ of the radial swing of the scanning head each time. i Calculate as follows: i i =Θ i -I i-1 =arcsin(R n,i / S n,i )-arcsin(R n,i-1 / S n,i-1 ) In the formula, Θ i R is the angle between the ray emitted after the i-th radial swing of the scanning head and the initial azimuth line (i≥1, Θ0=0); n,i S is the perpendicular distance from the point where the ray emitted after the i-th radial oscillation of the scanning head intersects the reference contour line to the initial azimuth line (n=1, indicating that the ray emitted by the scanning head intersects the reference contour line); n,i The distance from the laser scanning head to the point where the ray emitted after the i-th radial oscillation of the scanning head intersects with the reference contour line (n=1, indicating that the ray emitted by the scanning head intersects with the reference contour line).
4. The method according to claim 1, characterized in that, In the radial angle θ i Below, the angle α of the scanning head axis rotation for each contour line is obtained through iterative transition interpolation between each contour line and the next contour line. i,j Among them, the angle α of the scanning head axis rotation each time. i,j Calculate as follows: a i,j =Tol×360 / (2π×r n,i,m ) In the formula, Tol is the expected scan spacing; R n,i The perpendicular distance from the point where the ray emitted after the i-th radial oscillation of the scanning head intersects the reference contour line to the initial azimuth line (n≥1, indicating that the ray emitted by the scanning head intersects the n-th contour line); r n,i,m For R n,i With R n+1,i The distance value obtained by the m-th iteration transition interpolation (n≥1, indicating that the ray emitted by the scan head intersects with the n-th contour line).
5. A three-dimensional laser scanner data acquisition system, characterized in that, include: The information setting unit is used to set the spatial orientation information of the scanning head, including the spatial coordinates of the scanning head, the azimuth and tilt angles at the initial position, and the radial range of the scanning head; The pre-scanning unit is used to facilitate users in setting up a pre-scanning scheme according to the complexity of the area to be tested. The selection unit is used to obtain 2*N based on the pre-scan results. p The outline of the area to be measured is drawn, and from 2*N p The longest contour line among the contour lines is selected as the baseline contour line. The calculation unit is used to calculate each radial oscillation angle θ. i and the axial rotation angle α under that radial angle i,j ; Equidistant scanning units are used to sequentially scan according to each radial swing angle θ. i and the axial rotation angle α under that radial angle i,j Laser scanning is performed to obtain three-dimensional spatial data points of the area to be measured.