An automated iterative monitoring method and system for preventing the swaying of a test platform.

Abstract

This invention discloses an automated iterative monitoring method and system for preventing platform swaying. This invention relates to the field of engineering surveying technology, addressing the problem that existing methods are prone to measurement errors, making continuous stakeout and monitoring via a moving platform difficult. This invention acquires images of at least three non-collinear fixed base points with known absolute coordinates and an image of the forward stakeout target; calculates the absolute coordinates and attitude parameters of the platform on the moving platform; combines the absolute coordinates of the platform with the target image parameters synchronously acquired by the forward camera to calculate the absolute coordinates of the stakeout target; and uses the newly calculated stakeout target as the base point to drive the platform in iterative forward measurement. This method achieves fast measurement speed through synchronous imaging by front and rear cameras, fundamentally eliminating platform sway errors, effectively suppressing error accumulation through forward iteration using base points, and enabling real-time correction of the zoom lens via the target group, thus realizing long-distance, automated, and high-precision engineering stakeout and structural deformation monitoring.

Description

Technical Field

[0001] This invention relates to the field of engineering measurement technology, and in particular to an automated iterative monitoring method and system for preventing the swaying of a measuring platform base point. Background Technology

[0002] In modern building construction, large-scale structure operation and maintenance, tunnel construction, and linear engineering construction, it is generally necessary to lay out the absolute coordinates of landmark points or to conduct long-term displacement, settlement, and convergence monitoring of key monitoring points. Existing surveying methods mostly employ total stations for manual or automated measurement. The basic process is as follows: the total station is set up on a known coordinate base point, and after leveling and orientation, the telescope is rotated to aim at the point to be measured. The coordinates of the point to be measured are then calculated by measuring angles and distances.

[0003] The existing measurement methods described above have the following drawbacks: During the rotational scanning process of the total station, the base, tripod, or frame of the measuring platform is prone to slight deformation, displacement, or swaying, leading to a shift in the station's reference and directly introducing significant measurement errors. In long-distance, continuous construction, these errors accumulate, severely affecting the accuracy of the layout and the reliability of monitoring. Furthermore, traditional total stations rely on single-lens rotational measurement, making it difficult to achieve fully automated, non-contact, and highly stable continuous layout and monitoring. Therefore, there is an urgent need for a layout and monitoring method that can eliminate station deformation and sway errors, enable automated continuous advancement, and provide stable and reliable accuracy. Summary of the Invention

[0004] The purpose of this invention is to provide an automated iterative monitoring method and system for preventing the swaying of the measuring platform base point, in order to solve the problems that existing measurement methods are prone to measurement errors and difficult to achieve continuous stakeout and monitoring.

[0005] In a first aspect, the present invention provides an automated iterative monitoring method for the forward movement of a monitoring platform's swaying reference point, comprising the following steps: Step 1: Acquire images of at least three fixed base points with known absolute coordinates, wherein the fixed base points are not collinear, and acquire an image of at least one target to be staked out in front; wherein, the measuring platform is mounted on a mobile carrier, and the measuring platform integrates a computing unit, a rear camera and a front camera, and the computing unit is connected to the rear camera and the front camera respectively; the images of the fixed base points are acquired by the rear camera, and the images of the staked out target are acquired synchronously by the front camera.

[0006] Step 2: Based on the absolute coordinates of the fixed base point and its position information in the image captured by the rear camera, calculate the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier.

[0007] Step 3: Calculate the absolute coordinates of the lofting target based on the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier, as well as the image parameters of the lofting target synchronously acquired by the forward-facing camera.

[0008] Step 4: Using the lofting target as a new fixed base point, drive the mobile carrier to move forward.

[0009] Step 5: Repeat steps 1 to 4 to achieve automated stakeout and monitoring with fixed base points iterative forward.

[0010] Furthermore, in step one, the front-facing camera and the rear-facing camera are telephoto lenses, fixed-focus lenses, or zoom lenses that are fixedly mounted on the measuring platform of the mobile carrier or mounted on the two-dimensional scanning platform.

[0011] Further, step two includes: based on the images captured by the rear-facing camera, identifying the image center of each fixed base point, and combining the ranging function to determine the straight-line distance from the measuring platform on the mobile carrier to each fixed base point, as well as the spherical coordinate angle of each fixed base point relative to the measuring platform, wherein the spherical coordinate angle includes azimuth and polar angle; for any fixed base point, subtracting the relative rectangular coordinate offset obtained by converting the straight-line distance, azimuth, and polar angle of the fixed base point from its absolute coordinates to obtain the absolute coordinates of the measuring platform represented by that fixed base point; constructing a system of equations using the absolute coordinate expressions of the measuring platform represented by at least three non-collinear fixed base points, and obtaining the unique absolute coordinate value of the measuring platform by solving the system simultaneously; after knowing the absolute coordinates of the measuring platform, determining the pointing orientation of the measuring platform in the global coordinate system based on the absolute coordinates of any fixed base point and the absolute coordinates of the measuring platform.

[0012] Further, step three includes: identifying the image center of the stakeout target based on the image synchronously acquired by the forward-facing camera, and determining the straight-line distance from the measuring platform on the mobile carrier to the stakeout target, as well as the spherical coordinate angle of the stakeout target relative to the measuring platform, based on the straight-line distance, azimuth angle, and polar angle; converting the spherical coordinate measurement parameters of the stakeout target relative to the measuring platform into relative rectangular coordinate offsets in the local coordinate system of the measuring platform based on the straight-line distance, azimuth angle, and polar angle; and vector-superimposing the absolute coordinates of the measuring platform and the relative rectangular coordinate offsets in the global absolute coordinate system to obtain the absolute coordinates of the stakeout target.

[0013] Furthermore, based on the image parameters of the stakeout target synchronously acquired by the forward-facing camera, the absolute coordinates of the stakeout target are calculated, including: identifying and obtaining the image center coordinates of at least one stakeout target based on the image acquired by the forward-facing camera; calculating the difference in row and column pixel counts between the image of the stakeout target and the image center based on the image center coordinates; and calculating the azimuth and polar angles of the stakeout target relative to the measuring platform based on the known focal length of the precise imaging lens of the forward-facing camera, the difference in row and column pixel counts.

[0014] Furthermore, the calculation of the azimuth and polar angles of the fixed base point relative to the measuring platform, and the calculation of the azimuth and polar angles of the stakeout target relative to the measuring platform, are performed based on the known focal lengths of the precise imaging lenses of the rear camera and the front camera, respectively. When the rear camera and / or the front camera are zoom lenses, the calculation also includes a step of calibrating and correcting the real-time optical magnification of the corresponding cameras. The calibration and correction steps include: A target group consisting of multiple targets with fixed spacing is obtained. In the image captured by the zoom lens to be calibrated, the image center coordinates of any two targets are determined. Based on the image center coordinates of the two targets, the difference in the number of row pixels in the image of the center of the two targets is calculated. Based on the known actual physical distance between the fixed-spacing targets, the difference in the number of row pixels, and the known camera pixel size, the precise imaging lens focal length of the zoom lens at the current focal length is calculated. Based on the precise imaging lens focal length, the real-time optical magnification of the zoom lens is calibrated and corrected.

[0015] Furthermore, the mobile carrier includes a railcar, a mobile trolley, a car chassis, or a drone.

[0016] Furthermore, by repeatedly executing steps one to three at different times, the absolute coordinates of the same lofting target at different times are obtained, and the displacement or deformation of the lofting target is calculated by comparison, thereby realizing structural deformation monitoring.

[0017] Furthermore, the method is applied to tunnel and road bridge engineering to achieve monitoring and positioning attitude measurement of surrounding rock settlement, horizontal convergence or slant distance convergence, rock drill posture, and road and bridge slope safety deformation.

[0018] Secondly, the present invention provides an automated iterative monitoring system for anti-swaying base points, comprising: at least three fixed base points with known absolute coordinates and a measuring platform, wherein the fixed base points are not collinearly arranged, and the measuring platform is installed on a mobile carrier; the measuring platform integrates a computing unit, a rear camera and a front camera, and the computing unit is connected to the rear camera and the front camera respectively.

[0019] The rear-facing camera is used to face and identify the fixed base point.

[0020] The forward-facing camera is used to synchronously face and identify the lofting target or a group of lofting targets consisting of multiple lofting targets.

[0021] The computing unit is used to acquire images of at least three fixed base points with known absolute coordinates; calculate the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier based on the absolute coordinates of the fixed base points and their position information in the images acquired by the rear camera; calculate the absolute coordinates of the laying-out target based on the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier, as well as the image parameters of the laying-out target synchronously acquired by the front camera; use the laying-out target as a new fixed base point to drive the mobile carrier to move forward; repeat the above process to achieve automated laying-out and monitoring of fixed base points iteratively forward.

[0022] The beneficial effects of this invention are as follows: The automated iterative monitoring method and system for preventing platform swaying addresses the problem of accumulated errors caused by platform deformation and swaying due to rotating scanning in traditional total station measurement methods. By establishing fixed reference points and employing simultaneous imaging with dual front and rear cameras, this invention fundamentally avoids platform reference offset caused by equipment rotation during measurement, thus eliminating this source of error in principle. The fixed-point iterative measurement method effectively suppresses error accumulation in long-distance continuous measurement, significantly improving the long-term accuracy and reliability of stakeout and monitoring. Simultaneously, the use of fixed-interval target groups for real-time calibration of the zoom lens solves the problem of low focal length accuracy of zoom lenses, ensuring measurement stability at different distances. This method supports various mobile carriers such as railcars, mobile carts, and even drones, enabling truly fully automated and contactless continuous operation. It can adapt to complex, high-risk, or traditionally difficult-to-cover engineering scenarios such as tunnels, bridges, slopes, and aerial hovering. While achieving high-precision coordinate layout, it can also automatically monitor structural deformation, displacement, settlement, and convergence by comparing coordinates at different time periods. It has outstanding advantages such as high precision, good stability, high degree of automation, and strong environmental adaptability. Attached Figure Description

[0023] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0024] Figure 1 The diagram shows the composition and principle of the automatic iterative monitoring system for the anti-shaking base point of the test platform according to the present invention.

[0025] Figure 2This is a schematic diagram of the target group and magnification correction in this invention.

[0026] Figure 3 This is a schematic diagram of the forward iterative layout and monitoring process of the present invention.

[0027] Illustration: 1-Fixed base point; 2-Rear camera; 3-Front camera; 4-Mobile carrier; 5-Target group for placement; 6-Calculation unit. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The technical solutions provided by various embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0029] Please see Figures 1 to 3 This invention provides an automated iterative monitoring method for preventing the swaying of a test platform, comprising the following steps: Step 1: Acquire images of at least three fixed base points with known absolute coordinates, the fixed base points being non-collinear, and acquire an image of at least one target to be laid out in front; wherein, the test platform is installed on a mobile carrier, and the test platform integrates a computing unit, a rear camera, and a front camera, the computing unit being connected to the rear camera and the front camera respectively; the images of the fixed base points are acquired by the rear camera, and the images of the target are acquired synchronously by the front camera.

[0030] Specifically, at least three fixed base points with known absolute coordinates are set up. A measuring platform integrating a rear-facing camera, a front-facing camera, and a computing unit is mounted on a mobile carrier. To improve measurement accuracy, the front-facing and rear-facing cameras can be fixedly mounted on the measuring platform of the mobile carrier, or they can be telephoto lenses mounted on a 2D scanning platform, or they can be fixed-focus or zoom lenses. Setting up one rear-facing and one front-facing camera, or multiple cameras, achieves rapid measurement with no blind spots in the coverage of the base points and the target points. Setting up simultaneous image capture and calculation by the rear-facing and front-facing cameras significantly shortens the measurement time, even to the microsecond level, enabling uninterrupted measurement without moving the measuring platform. Simultaneous image capture and calculation by the rear-facing and front-facing cameras avoids measurement errors caused by platform deformation or base offset during the measurement process.

[0031] Step 2: Based on the absolute coordinates of the fixed base point and its position information in the image acquired by the rear camera, calculate the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier.

[0032] This invention identifies the image center of each fixed base point based on images captured by a rear-facing camera. Combined with a ranging function, it determines the straight-line distance from the measuring platform on the moving carrier to each fixed base point, as well as the spherical coordinate angle of each fixed base point relative to the measuring platform. The spherical coordinate angle includes azimuth and polar angle. For any fixed base point, the absolute coordinates of the measuring platform represented by that fixed base point are obtained by subtracting the relative rectangular coordinate offset converted from the straight-line distance, azimuth, and polar angle of that fixed base point from its absolute coordinates. A system of equations is constructed using the absolute coordinate expressions of at least three non-collinear fixed base points, and a unique absolute coordinate value of the measuring platform is obtained by solving the system simultaneously. Given the absolute coordinates of the measuring platform, the pointing orientation of the measuring platform in the global coordinate system is determined based on the absolute coordinates of any fixed base point and the absolute coordinates of the measuring platform.

[0033] Specifically, three non-collinear fixed base points are set. , , The three-dimensional absolute coordinates are: .

[0034] The measurement parameters of the measuring platform C relative to the fixed base point can be obtained from scanning and ranging equipment, and are therefore known parameters. (The distance from the measuring platform to the fixed base point is missing.) , , The straight-line distances are respectively The measuring platform scans the fixed reference point. , , The spherical coordinate angles (with the measuring platform itself as the origin of the spherical coordinates) are as follows: , , .

[0035] Spherical coordinates definition: It is the azimuth angle (the angle between the azimuth angle and the X-axis when the azimuth platform is rotated around the Z-axis). It is the polar angle (the angle between the polar angle and the Z-axis of the measuring platform). The radius vector (the straight-line distance from the measuring platform to the target). The straight-line distance from the measuring platform to any target i to be measured. azimuth angle of scan target i Polar angle . Formula for distance between two points in space:

[0036] This represents the straight-line distance between two points M and N in space. , , These represent the x-coordinate, y-coordinate, and vertical coordinate of point M in a three-dimensional rectangular coordinate system, respectively. , , These represent the x-coordinate, y-coordinate, and vertical coordinate of point N in a three-dimensional rectangular coordinate system, respectively.

[0037] Formula for converting spherical coordinates to relative rectangular coordinates (local coordinate system of the measuring station):

[0038] In the formula It represents the coordinate offset of the target point relative to the measuring station, and is the core quantity connecting the local coordinate system of the measuring station and the global absolute coordinate system.

[0039] Absolute coordinates of the measuring station Detailed derivation: Establish the coordinate relationship between the fixed base point and the measuring platform. Using the formula for converting spherical coordinates to relative rectangular coordinates, the relative coordinates of the fixed base point in the local coordinate system of the measuring platform are equal to the absolute coordinates of the fixed base point minus the absolute coordinates of the measuring platform. For any fixed base point... There is a core relational expression: (1) The physical meaning of this equation is that the relative coordinate offset of the local coordinate system of the measuring station is completely equivalent to the coordinate difference of the global absolute coordinate system, which is the core equation in this derivation. Decomposing it into a single-base-point measuring station coordinate expression, and transforming the above equation, we can directly solve for the measuring station coordinate expression expressed by a single fixed base point. For example: (2-1) Similarly, the fixed base points can be written out. , The corresponding coordinate expression for the measuring station: (2-2) (2-3) Solve the system of equations to find a unique solution. Since the absolute coordinates of the measuring station are unique, the above three equations are pairwise equal, and solving them together yields a system of three linear equations in three variables.

[0040] Joint fixed base points With fixed base point (X / Y / Z are equal): (3) Joint fixed base points With fixed base point : (4) The final unique expression for the coordinates of the measuring platform: Equations (2-1), (2-2), and (2-3) are all direct solutions for the coordinates of the measuring platform. Since the measurement parameters and the coordinates of the fixed base point are known quantities, a unique solution can be directly calculated (the calculation results of the three sets of formulas can be mutually verified in engineering). A fixed base point is selected. The expression is used as the final formula for the coordinates of the measuring station (either one can be chosen in the project).

[0041] (5) The absolute coordinates of the measuring platform can be derived from the known absolute coordinates of a single fixed base point and the measurement parameters of the measuring platform for that fixed base point. In direct solution, the core function of the three fixed reference points is to mutually verify the measurement accuracy and eliminate random errors.

[0042] Step 3: Calculate the absolute coordinates of the target based on the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier, as well as the image parameters of the target acquired synchronously by the forward-facing camera.

[0043] This invention identifies the image center of the stakeout target based on images synchronously acquired by a forward-facing camera, and, combined with a ranging function, determines the straight-line distance from the measuring platform on the moving carrier to the stakeout target, as well as the spherical coordinate angle of the stakeout target relative to the measuring platform, including the azimuth and polar angles. Based on the straight-line distance, azimuth, and polar angles, the spherical coordinate measurement parameters of the stakeout target relative to the measuring platform are converted into relative rectangular coordinate offsets in the local coordinate system of the measuring platform. In the global absolute coordinate system, the absolute coordinates of the measuring platform and the relative rectangular coordinate offsets are vector-superimposed to obtain the absolute coordinates of the stakeout target.

[0044] absolute coordinates of target i Detailed derivation: Absolute coordinates of the measuring station The above method has been used to solve the problem, which forms the basis for solving the target coordinates. The coordinate offset of the target relative to the measuring platform is established, and the measuring platform scans the target i to obtain the spherical coordinates. Using the formula for converting spherical coordinates to relative rectangular coordinates, we obtain the absolute coordinate offset of target i relative to the measuring platform C: (6) In the formula These represent the coordinate offsets of target i relative to the measuring platform C in the X, Y, and Z axes, respectively.

[0045] The absolute coordinates of the target and the absolute coordinates of the measuring platform are correlated. In the global absolute coordinate system, the absolute coordinates of target i are equal to the absolute coordinates of the measuring platform plus the coordinate offset of the target relative to the measuring platform. The core correlation formula is: (7) Substituting the offset from equation (6) into equation (7), we obtain the final derivation of the absolute coordinates of the target i: (8) Substituting the coordinate equation (5) of the measuring platform into (8), we can obtain the expansion directly expressed by the base point parameters and the target measurement parameters, without needing to calculate the measuring platform coordinates separately. The target coordinates can be solved in one step:

[0046] The absolute coordinates of target i are a linear superposition of the absolute coordinates of the measuring platform and the relative offset. The solution can be obtained directly by only needing the coordinates of the measuring platform and the measurement parameters of the measuring platform relative to target i.

[0047] In addition, the method for obtaining image parameters of the stakeout target synchronously acquired by the forward-facing camera includes: identifying and acquiring the image center coordinates of at least one stakeout target in the image acquired by the forward-facing camera; calculating the difference in row and column pixel counts between the image center coordinates and the image center; and calculating the azimuth and polar angles of the stakeout target relative to the measuring platform based on the known focal length of the forward-facing camera's precise imaging lens and the differences in row and column pixel counts.

[0048] When the forward-facing camera is a zoom lens, the lofting target is a target group composed of multiple targets, and the spacing between any two targets in the target group is fixed. After calculating the difference in the number of row pixels and the difference in the number of column pixels between the image of the lofting target and the image center, the method further includes: obtaining the image center coordinates of the two fixed-spacing targets in the image captured by the forward-facing camera; calculating the difference in the number of row pixels in the image of the center of the two targets based on the image center coordinates of the two targets; calculating the precise imaging lens focal length of the zoom lens at the current focal length based on the known actual physical distance between the fixed-spacing targets, the difference in the number of row pixels, and the known camera pixel size; and calibrating and correcting the real-time optical magnification of the forward-facing camera based on the precise imaging lens focal length.

[0049] The forward-facing camera synchronously acquires images of the target in front, obtaining the target image coordinates, azimuth, polar angle, and distance r. Since the image sensor does not require centering each target (total station crosshair alignment) to calculate the azimuth and polar angles, but instead calculates them based on the difference in the number of rows and columns of pixels between the target i image and the image center, precise focal lengths of the front and rear camera imaging lenses are required. and .

[0050] Figure 2 In this diagram, D represents the center-to-center distance of the fixed target, for example, D = 200 mm. According to the present invention, the absolute coordinates of the staked-out target can be accurately calculated in the following manner.

[0051] When using a zoom lens for imaging, a target group with a fixed spacing D is used. The optical magnification M of the camera, that is, the displacement of the target corresponding to the measurement point of a single pixel of the camera, can be calibrated and corrected in real time as shown in formula (10). Combined with the measurement coordinates of the base point, the imaging parameters of the target and the magnification after correction, the absolute coordinates of the stakeout target can be accurately calculated. With a focal length of 100mm and a camera pixel size of =0.0008mm, 8000 Taking 6000 pixels as an example, the precise focal length at distance S (Solution to the inability of zoom lenses to accurately obtain high-precision focal length) The question is:

[0052] in This is the difference in the number of pixels in the center row of two targets with a fixed spacing D. The above formula relates to the focal lengths of the front and rear cameras. and Both are applicable.

[0053] According to precision The precise azimuth and polar angle of target i can be obtained from the following formulas:

[0054] K=1,2,3.

[0055] The row pixel difference between the center of the target i image and the center (4000, 3000); The column pixel difference between the center of the target i image and the center (4000, 3000); For scanning measurement of fixed reference points on the measuring platform , , Polar angle reading of the vertical scanning platform; For scanning measurement of fixed reference points on the measuring platform , , The azimuth reading of the horizontal scanning platform. (11)(12)(13)(14) and Substituting into formula (8) will give the absolute coordinates of the target i to be tested.

[0056] Step 4: Use the target as a new fixed base point and drive the moving carrier forward.

[0057] Step 5: Repeat steps 1 to 4 to achieve automated stakeout and monitoring with fixed base points iterative forward.

[0058] This invention uses the newly calculated stakeout target as the temporary fixed base point for the next stage. By moving the mobile carrier platform forward and repeating the above steps, it achieves the functions of iterative forward stakeout, continuous automated stakeout, and monitoring of the fixed base point.

[0059] Specifically, the mobile carrier of this invention includes a railcart, a mobile trolley, a car chassis, or a drone, which can complete measurement operations while moving on the ground or hovering in the air. By repeatedly executing steps one to three at different times, the absolute coordinates of the same stakeout target at different times are obtained. The displacement or deformation of the stakeout target is calculated by comparison, thereby realizing structural deformation monitoring. The method of this invention can be applied to tunnel and road bridge engineering to realize the settlement of surrounding rock, horizontal convergence or slant distance convergence, rock drill posture, deformation safety monitoring of road and bridge slope safety, and positioning posture measurement.

[0060] This invention also provides an automated iterative monitoring system for anti-swaying base points, comprising: at least three fixed base points 1 with known absolute coordinates and a measuring platform, wherein the fixed base points 1 are not collinearly arranged, and the measuring platform is mounted on a mobile carrier 4; the measuring platform integrates a computing unit 6, a rear-facing camera 2, and a front-facing camera 3, and the computing unit 6 is signal-connected to the rear-facing camera 2 and the front-facing camera 3 respectively. The rear-facing camera is used to face and identify the fixed base points. The front-facing camera is used to synchronously face and identify the stakeout target or a group of stakeout targets 5 composed of multiple stakeout targets. The computing unit is used to acquire images of at least three fixed base points with known absolute coordinates; calculate the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier based on the absolute coordinates of the fixed base points and their position information in the images acquired by the rear camera; calculate the absolute coordinates of the laying-out target based on the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier, as well as the image parameters of the laying-out target acquired synchronously by the front camera; use the laying-out target as a new fixed base point to drive the mobile carrier to move forward; repeat the above process to realize automated laying-out and monitoring of fixed base points iteratively forward.

[0061] The present invention will be described below with reference to several specific embodiments.

[0062] Example 1: Monitoring of Settlement and Convergence of Surrounding Rock in Tunnels Three fixed benchmarks with known absolute coordinates are set up in the stabilized section of the tunnel. An automated measuring platform is installed on the tunnel construction trolley, with the rear camera facing the rear benchmark and the front camera aimed at the surrounding rock monitoring target. The two cameras simultaneously image and calculate the coordinates of the measuring host device and the target. The next section of the surrounding rock target is measured by continuously zooming through a motor-driven system. The absolute coordinates of the target at that section are calculated by simultaneously capturing images with the front and rear cameras. This allows for the measurement of safety monitoring elements such as settlement, convergence, and slant distance convergence required for surrounding rock monitoring. The optical magnification M, which is the displacement of a single pixel of the camera corresponding to the measuring point target, is corrected using fixed-spaced targets to accurately calculate the absolute coordinates of the surrounding rock monitoring points. Before the trolley moves forward, three new benchmark targets are set at a fixed point. The absolute coordinates of the three new benchmarks are measured and calculated. The trolley moves forward about a certain distance (e.g., 30m), and the newly calculated benchmark targets are used as benchmarks to calculate the new absolute coordinates of the measuring host on the trolley. The measurement continues iteratively forward. Because the front and rear cameras capture images simultaneously, small-distance shaking of the measuring platform trolley does not affect the measurement.

[0063] By comparing monitoring data from different time periods, we obtained the changes in surrounding rock settlement, horizontal convergence, and slope distance.

[0064] Example 2: UAV Aerial Positioning and Attitude Measurement Three fixed reference points with known coordinates are set up in an open area on the ground. The measuring platform is mounted on a UAV. When the UAV reaches the preset measurement position and hovers in the air, the rear camera identifies the ground reference points. The front camera observes the target to be measured and calculates the position and attitude of the UAV through the absolute coordinates of the reference points. The UAV flies forward to the preset measurement position and uses the target to be measured, which has just been calculated, as the new reference point to continue iterative measurement, so as to achieve high-precision aerial positioning and attitude measurement.

[0065] In summary, this invention employs fixed-base-point iterative closed-loop convergence measurement, significantly suppressing error accumulation and improving continuous stakeout accuracy; dual-camera synchronous imaging eliminates the need for rotational scanning from the base point to the measurement point, fundamentally avoiding errors caused by frame deformation or displacement during the measurement process of measurement systems such as total stations; the measuring platform can be mounted on various carriers such as trolleys and drones, adapting to complex scenarios such as ground, air, bridges, slopes, and tunnels; real-time correction of optical magnification using fixed-interval D-targets achieves both high-precision measurement and ensures measurement stability at different distances; and fully automated operation enables stakeout, displacement monitoring, settlement / convergence monitoring, positioning, and attitude measurement.

[0066] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention.

Claims

1. A method for automated iterative monitoring of the anti-sway base point of a measuring platform, characterized in that, Includes the following steps: Step 1: Acquire images of at least three fixed base points with known absolute coordinates, wherein the fixed base points are not collinear, and acquire an image of at least one target to be staked out in front; wherein, the measuring platform is mounted on a mobile carrier, and the measuring platform integrates a computing unit, a rear camera, and a front camera, and the computing unit is connected to the rear camera and the front camera respectively; the images of the fixed base points are acquired by the rear camera, and the images of the staked out target are acquired synchronously by the front camera; Step 2: Based on the absolute coordinates of the fixed base point and its position information in the image captured by the rear camera, calculate the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier. Step 3: Calculate the absolute coordinates of the lofting target based on the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier, and the image parameters of the lofting target synchronously acquired by the forward-facing camera. Step 4: Using the lofting target as a new fixed base point, drive the mobile carrier to move forward; Step 5: Repeat steps 1 to 4 to achieve automated stakeout and monitoring with fixed base points iterative forward.

2. The automated iterative monitoring of forward movement of a wobble base point of a test bed according to claim 1, wherein, In step one, the front-facing camera and the rear-facing camera are telephoto lenses, fixed-focus lenses, or zoom lenses that are fixedly mounted on the measuring platform of the mobile carrier or mounted on the two-dimensional scanning platform.

3. The automated iterative monitoring method for the anti-swaying base point of the monitoring platform according to claim 1, characterized in that, Step two includes: Based on the images captured by the rear-facing camera, the image center of each fixed base point is identified, and combined with the ranging function, the straight-line distance from the measuring platform on the mobile carrier to each fixed base point, as well as the spherical coordinate angle of each fixed base point relative to the measuring platform, are determined. The spherical coordinate angle includes the azimuth angle and the polar angle. For any fixed base point, the absolute coordinates of the measuring station represented by that fixed base point are obtained by subtracting the relative rectangular coordinate offset obtained by converting the straight distance, azimuth, and polar angle of that fixed base point from its absolute coordinates. A system of equations is constructed using the absolute coordinate expressions of at least three non-collinear fixed base points, and the unique absolute coordinate values ​​of the measuring station are obtained by solving the system simultaneously. After knowing the absolute coordinates of the measuring station, the orientation of the measuring station in the global coordinate system is determined based on the absolute coordinates of any fixed base point and the absolute coordinates of the measuring station.

4. The automated iterative monitoring method for the forward movement of the anti-swaying base point as described in claim 3, characterized in that, Step three includes: Based on the images synchronously acquired by the forward-facing camera, the image center of the stakeout target is identified, and combined with the ranging function, the straight-line distance from the measuring platform on the mobile carrier to the stakeout target, as well as the spherical coordinate angle of the stakeout target relative to the measuring platform, are determined. The spherical coordinate angle includes the azimuth angle and the polar angle. Based on the straight-line distance, azimuth angle, and polar angle, the spherical coordinate measurement parameters of the stakeout target relative to the measuring platform are converted into relative rectangular coordinate offsets in the local coordinate system of the measuring platform. In the global absolute coordinate system, the absolute coordinates of the measuring platform are vector-superimposed with the relative rectangular coordinate offset to obtain the absolute coordinates of the stakeout target.

5. The automated iterative monitoring method for the forward movement of the anti-swaying base point as described in claim 4, characterized in that, Based on the image parameters of the stakeout target synchronously acquired by the forward-facing camera, the absolute coordinates of the stakeout target are calculated, including: Based on the images captured by the forward-facing camera, identify and obtain the image center coordinates of at least one lofting target; Based on the coordinates of the image center, calculate the difference in the number of row pixels and the difference in the number of column pixels between the image of the target and the image center. Based on the known focal length of the precise imaging lens of the forward-facing camera, the difference in the number of rows and columns of pixels, calculate the azimuth and polar angle of the target relative to the measuring platform.

6. The automated iterative monitoring method for the forward movement of the anti-swaying base point as described in claim 5, characterized in that, The calculation of the azimuth and polar angles of the fixed reference point relative to the measuring platform, and the calculation of the azimuth and polar angles of the stakeout target relative to the measuring platform, are performed based on the known focal lengths of the precise imaging lenses of the rear camera and the front camera, respectively. When the rear camera and / or the front camera are zoom lenses, the calculation also includes a step of calibrating and correcting the real-time optical magnification of the corresponding cameras. The calibration and correction steps include: Obtain the image center coordinates of any two targets in the image captured by the zoom lens to be calibrated, which consists of a target group composed of multiple targets with fixed spacing. Based on the image center coordinates of the two targets, calculate the difference in the number of row pixels in the image where the center of the two targets is located; Based on the known spacing, the actual physical distance between the fixed targets, the difference in the number of rows, and the known camera pixel size, the accurate imaging lens focal length of the zoom lens at the current focal length is calculated. The real-time optical magnification of the zoom lens is calibrated and corrected based on the focal length of the precise imaging lens.

7. The automated iterative monitoring method for the forward movement of the anti-swaying base point as described in claim 1, characterized in that, The mobile carrier includes a railcar, a mobile trolley, a car chassis, or a drone.

8. The automated iterative monitoring method for the forward movement of the anti-swaying base point as described in claim 1, characterized in that, By repeatedly executing steps one through three at different times, the absolute coordinates of the same stakeout target at different times are obtained. The displacement or deformation of the stakeout target is then calculated by comparison, thereby realizing structural deformation monitoring.

9. The automated iterative monitoring method for the forward movement of the anti-swaying base point of the monitoring station according to claim 1, characterized in that, The method is applied to tunnel and road bridge engineering to achieve monitoring and positioning attitude measurement of surrounding rock settlement, horizontal convergence or slant distance convergence, rock drill posture, and road and bridge slope safety deformation.

10. An automated iterative monitoring system for preventing the swaying of a test platform, characterized in that, include: At least three fixed base points with known absolute coordinates and a measuring platform, wherein the fixed base points are not collinearly arranged, and the measuring platform is mounted on a mobile carrier; the measuring platform integrates a computing unit, a rear camera and a front camera, and the computing unit is connected to the rear camera and the front camera respectively. The rear-facing camera is used to face and identify the fixed base point; The forward-facing camera is used to synchronously face and identify the lofting target or a group of lofting targets composed of multiple lofting targets; The calculation unit is used to acquire images of at least three fixed base points with known absolute coordinates; calculate the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier based on the absolute coordinates of the fixed base points and their position information in the images acquired by the rear camera; calculate the absolute coordinates of the lofting target based on the absolute coordinates and attitude parameters of the measuring platform on the mobile carrier, as well as the image parameters of the lofting target synchronously acquired by the front camera; and use the lofting target as a new fixed base point to drive the mobile carrier to move forward. Repeat the above process to achieve automated stakeout and monitoring by iterating forward from a fixed base point.

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