Laser target localization method and implementation apparatus therefor, and tunnel deformation monitoring method

Abstract

A laser target localization method and an implementation apparatus therefor, and a tunnel deformation monitoring method. The laser target localization method comprises: providing in a spaced manner a laser ranging module (31) and a target on an object to be subjected to detection (S1); the laser ranging module (31) projecting an emergent laser onto the target (S2); establishing a sampling point coordinate system by using a projection point of the emergent laser as the coordinate origin (S3); making the projection point of the emergent laser move in a spiral line around the coordinate origin in the sampling point coordinate system, and collecting real-time coordinate values of all sampling points (100) in the sampling point coordinate system, and real-time intensity values of reflected light of the emergent laser at the positions of all the sampling points (100) (S4); and after the spiral-line movement ends, determining the region of the target on the basis of the real-time intensity values of the reflected light at the positions of all the sampling points (100), and on the basis of the coordinate values of all the sampling points (100) in the region of the target, determining the central point of the target (S5).

Description

Laser target finding method and its implementation device and tunnel deformation monitoring method

[0001] This application claims priority to Chinese Patent Application No. 202410926404.7, filed on July 11, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of deformation monitoring technology, such as a laser target finding method and its implementation device, and a tunnel deformation monitoring method. Background Technology

[0003] Deformation monitoring refers to the method of measuring the deformation of a monitored object or structure, which can be an area or a specific building or structure. Tunnel construction is an indispensable and important task in modern urban development. However, the stability and safety of tunnels are directly related to the safety of people's lives and property, and are issues that must be given priority during construction. To ensure the stability and safety of tunnels, tunnel deformation monitoring is essential.

[0004] Currently, the main methods for detecting tunnel deformation are total stations and laser scanners. Total stations can achieve high-precision measurements, but the measurements require manual, timed or intermittent operation, resulting in low detection efficiency and making it impossible to achieve automatic real-time monitoring of the entire tunnel. Laser scanners use laser beams for three-dimensional measurement, which can quickly obtain the surface morphology of the tunnel, but the accuracy is not high, and the subsequent computation is large and costly.

[0005] Summary of the Invention

[0006] This application provides a laser target finding method and its implementation device, as well as a tunnel deformation monitoring method, to improve the automation and intelligence of tunnel monitoring and realize real-time monitoring of tunnel deformation.

[0007] The following technical solution is adopted in this application:

[0008] This application provides a laser target finding method, including:

[0009] Laser ranging modules and targets are placed at intervals on the object being detected;

[0010] The laser ranging module projects an emitted laser toward the target;

[0011] A sampling point coordinate system is established with the projection point of the emitted laser as the origin;

[0012] The projection point of the emitted laser moves in a spiral motion around the origin of the coordinate system in the sampling point coordinate system, and collects the real-time coordinate values ​​of all sampling points in the sampling point coordinate system, as well as the real-time intensity values ​​of the reflected light of the emitted laser at all sampling point positions.

[0013] After the spiral motion ends, the target area is determined based on the real-time intensity value of the reflected light at all sampling point locations, and the center point of the target is determined based on the coordinate values ​​of all sampling points within the target area.

[0014] In some embodiments, the trajectory of the spiral motion is as follows: starting from the origin of the coordinate system, the projection point moves stepwise according to the step displacement. For each step, the projection point rotates 90° toward the origin of the coordinate system, and then moves stepwise again. For each step, the displacement value increases by one displacement difference, and the trajectory of the step movement is a straight line.

[0015] In some embodiments, the displacement difference is the displacement value of the step displacement when the projection point moves for the first time.

[0016] In some embodiments, the outer diameter of the trajectory of the helical motion is at least twice the outer diameter of the target.

[0017] In some embodiments, the target is provided with a reflective coating, and in response to determining that the emitted laser irradiates the reflective coating, the intensity value of the reflected light from the emitted laser is different from the intensity value of the reflected light from the emitted laser irradiating a non-target location.

[0018] This application provides an apparatus for implementing a laser target-finding method, comprising:

[0019] A base, wherein the base is disposed at a distance from the target;

[0020] A first drive assembly is disposed on the base, and the output end of the first drive assembly is provided with a mounting bracket. The first drive assembly is configured to drive the mounting bracket to rotate around a horizontal axis.

[0021] A second drive assembly is mounted on the mounting bracket, on which a laser ranging module is mounted. The second drive assembly is configured to drive the laser ranging module to rotate about a vertical axis.

[0022] In some embodiments, the apparatus for implementing the laser target finding method further includes a controller, which is disposed on the base and is communicatively connected to the first drive component and the second drive component.

[0023] In some embodiments, the distance between the first drive component and the horizontal axis is equal to the distance between the second drive component and the vertical axis.

[0024] In some embodiments, the first driving component and the second driving component are respectively driven by a micro servo driver.

[0025] This application provides a tunnel monitoring method, including:

[0026] Targets and the implementation device of the laser target finding method provided in this application are set on both sides of the tunnel. The laser target finding method provided in this application is used to find and locate the target and determine the center point of the target.

[0027] The laser emitted by the laser ranging module is projected onto the center point of the target;

[0028] The intensity of the reflected light from the emitted laser is collected in real time and compared with the collected intensity values. If the intensity value decreases, it is considered as a miss. Attached Figure Description

[0029] Figure 1 is a flowchart of the laser target finding method provided in an embodiment of this application;

[0030] Figure 2 is a schematic diagram showing the correspondence between the motion trajectory of the spiral motion in the sampling point coordinate system in the laser target finding method provided in the embodiment of this application;

[0031] Figure 3 is a schematic diagram of the structure of the device for implementing the laser target finding method provided in the embodiment of this application;

[0032] Figure 4 is a side view of the device for implementing the laser target finding method provided in an embodiment of this application;

[0033] Figure 5 is a schematic diagram illustrating the calculation principle of the stroke of the micro servo driver in the implementation device of the laser target finding method provided in the embodiments of this application;

[0034] Figure 6 is a flowchart of the tunnel monitoring method provided in an embodiment of this application.

[0035] In the picture:

[0036] 100. Sampling points;

[0037] 1. Base; 2. First drive assembly; 21. Mounting bracket; 22. Horizontal axis; 3. Second drive assembly; 31. Laser ranging module; 32. Vertical axis; 4. Controller. Detailed Implementation

[0038] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0040] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0041] As shown in Figures 1-6, embodiments of this application provide a laser target finding method and its implementation device, as well as a method for tunnel deformation detection using the laser target finding method and its implementation device.

[0042] As shown in Figure 1, the laser target-finding method includes the following steps:

[0043] S1, laser ranging module 31 and target are set at intervals on the object to be detected;

[0044] S2, the laser ranging module 31 projects the emitted laser toward the target;

[0045] S3, establish the sampling point 100 coordinate system with the projection point of the emitted laser as the origin;

[0046] S4, the projection point of the emitted laser moves in a spiral motion around the origin in the coordinate system of sampling point 100, and collects the real-time coordinate values ​​of all sampling points 100 in the coordinate system of sampling point 100, as well as the real-time intensity values ​​of the reflected light of the emitted laser at all sampling points 100.

[0047] S5. After the spiral motion ends, the target area is determined based on the real-time intensity value of the reflected light at all sampling points 100. The center point of the target is determined based on the coordinate values ​​of all sampling points 100 within the target area.

[0048] The laser target-finding method provided in this application can be used to detect fixed structures such as houses and bridges. In the following embodiments, a tunnel is used as an example. The laser target-finding method uses the emitted laser from the laser ranging module 31 to find the target. Based on the intensity change of the reflected light from the emitted laser, when the emitted laser is projected onto the target, it will have a set or abrupt intensity value of the reflected light. In this embodiment, the projection point of the emitted laser is used as the origin of the coordinate system, and a sampling point 100 coordinate system is established. The trajectory of the projection point is controlled to move in a spiral motion within the sampling point 100 coordinate system. When the spiral motion trajectory covers the target area, the target area can be determined based on the intensity value of the reflected light from the emitted laser. The coordinate values ​​of the sampling point 100 within the target area can determine the center point of the target, thereby achieving automatic laser target finding. It can be understood that this laser target-finding method can improve the initial target-finding efficiency and accuracy of the monitoring process, so as to start the monitoring process as soon as possible. This application realizes automatic intelligent target finding, greatly reducing construction time and debugging difficulty, and helping to reduce manpower expenditure and monitoring costs. It should be further explained that the laser ranging module 31 and the target have an initial approximate positioning during installation, so the initial projection point of the emitted laser can be located exactly in the target area, or even if it is located outside the target area, the distance will not be large, meaning that the spiral motion can traverse the target area. If the spiral motion trajectory cannot traverse the target area or only a small part of the target area is covered, the initial installation position can be adjusted to improve the target finding efficiency.

[0049] In step S4, the trajectory of the spiral motion is as follows: starting from the origin of the coordinate system, the projection point moves step by step according to the step displacement. For each step, the projection point rotates 90° toward the origin of the coordinate system, and then continues to move step by step. For each step, the displacement value increases by one displacement difference, and the trajectory of the step movement is a straight line.

[0050] As shown in Figure 2, the trajectory of the spiral motion is obtained through the linear displacement of the projection point. In the XOY coordinate system of sampling point 100, the initial projection point is defined as the origin O. The initial step displacement of the initial projection point is taken as a coordinate unit (1cm). After intersecting with multiple straight lines that are parallel or perpendicular to the coordinate axis at each coordinate unit, an intersection point (or grid point) is formed. Multiple intersection points are defined as sampling point 100 (black nodes in Figure 2). In this embodiment, a rectangular target with dimensions of 5cm × 5cm is used as an example. The spiral motion trajectory has dimensions of 10cm × 10cm. By controlling the projection point to move linearly with step displacement, the initial step displacement of the projection point is one coordinate unit along the positive Y-axis. Then, it rotates 90° to the right to change the direction of movement to the positive X-axis, continues to move one coordinate unit, and then rotates 90° towards the origin O, i.e., towards the negative Y-axis. After these two step movements, the step displacement increases by one displacement difference (in this embodiment, the displacement difference is one coordinate unit, i.e., 1cm). The projection point moves beyond the position of the origin along the negative Y-axis and turns back to the negative X-axis, and so on, forming a spiral motion trajectory. By setting the projection point to move in a spiral motion, it is easier to find the target position within the gradually expanding spiral area. Moreover, the projection point moves linearly within the sampling point coordinate system, which facilitates obtaining the coordinate value corresponding to the field strength value, simplifies the calculation process, and improves the target finding efficiency. In this embodiment, real-time field strength and real-time coordinate values ​​are collected at each sampling point 100.

[0051] In some embodiments, the displacement difference is the displacement value of the step displacement when the projection point moves for the first time.

[0052] In this embodiment, the displacement difference is one coordinate unit, as shown in Figure 2. The initial step displacement is 1cm, and the coordinate unit is set to 1cm. The projection point moves twice in each step, increasing by one coordinate unit. If a spiral motion trajectory with uniform intervals is achieved, it is beneficial to calculate and determine the position of the target.

[0053] In some embodiments, the outer diameter of the trajectory of the helical motion is at least twice the outer diameter of the target.

[0054] When the emission point of the emitted laser is located within the target area, the outer diameter of the spiral motion trajectory can be slightly larger than the target's outer diameter. When the emission point is outside the target area, the spiral motion trajectory must be at least twice the target's outer diameter. This ensures the spiral motion trajectory covers the entire target area as much as possible, improving the accuracy of determining the target's center point. When the origin O is exactly outside the target, after the emission point completes its spiral motion, the target area is exactly within the spiral motion trajectory. The intensity values ​​of sampling points 100 within this target area are equal. Based on the coordinate values ​​of sampling points 100 within the target area, the center point of the target area can be calculated. Then, the emission point of the emitted laser is adjusted to be located at the target's center point to complete target finding, allowing for subsequent real-time monitoring. It can be understood that the spiral motion trajectory can be adjusted based on the real-time intensity and coordinate values ​​collected during the emission point's motion. The initial projection point of the emitted laser can also be determined according to the laser target finding method provided in this application, so that the target position can be obtained within the motion trajectory of a certain size, which helps to reduce or reduce the travel of the laser ranging module 31 when controlling the projection point position and saves installation space.

[0055] In some embodiments, the target is provided with a reflective coating. When the emitted laser irradiates the reflective coating on the target, the reflective coating causes the intensity value of the reflected light of the emitted laser on the target to be different from the intensity value of the reflected light of the emitted laser irradiating a non-target location.

[0056] It is understandable that the laser emitted by the laser ranging module 31 is reflected after being projected onto the target. The reflective coating can reduce the energy loss of the reflected light so as to obtain reflected light with a larger intensity value. Based on the intensity value of the reflected light, it can be determined whether the projection point is located in the target area.

[0057] The laser target finding method implementation device provided in this application includes a base 1, a first driving component 2, and a second driving component 3. The base 1 and the target are arranged at a distance from each other. The first driving component 2 is disposed on the base 1, and the output end of the first driving component 2 is provided with a mounting bracket 21. The first driving component 2 is configured to drive the mounting bracket 21 to rotate around a horizontal axis 22. The second driving component 3 is disposed on the mounting bracket 21, and a laser ranging module 31 is mounted on the mounting bracket 21. The second driving component 3 is configured to drive the laser ranging module 31 to rotate around a vertical axis 32.

[0058] As shown in Figures 3 and 4, taking the L-shaped base 1 as an example, the first drive assembly 2 is fixed on the horizontal plate of the base 1. The output end of the first drive assembly 2 faces upward and can extend and retract in the vertical direction. One end of the mounting bracket 21 is connected to the output end of the first drive assembly 2, and the second end of the mounting bracket 21 is rotatably connected to the vertical plate of the base 1 via a horizontal shaft 22. When the output end of the first drive assembly 2 extends and retracts, the mounting bracket 21 rotates around the horizontal shaft 22, and the projection point moves along the Y-axis. The laser ranging module 31 is mounted on the mounting bracket 21. The first end of the laser ranging module 31 is rotatably connected to the mounting bracket 21 via a vertical shaft 32, and the second end of the laser ranging module 31 is connected to the output end of the second drive assembly 3. The output end of the second drive assembly 3 is set in the horizontal direction and can extend and retract to drive the laser ranging module 31 to rotate in the horizontal plane, thereby controlling the projection point to move along the X-axis. This embodiment of the application achieves movement control of the projection point by rotating the laser ranging module 31, which is suitable for deformation monitoring of large structures such as tunnels. When the laser ranging module 31 is far from the target, the projection point can be controlled to move in a straight line over a large distance by rotating the laser ranging module 31 at a small angle. This helps to save installation space, makes the drive control more flexible and convenient, and provides high control accuracy.

[0059] In some embodiments, the apparatus for implementing the laser target finding method further includes a controller 4, which is disposed on the base 1 and is communicatively connected to the first drive component 2 and the second drive component 3.

[0060] In this embodiment, both the first drive component 2 and the second drive component 3 employ miniature servo drives. By communicating with the miniature servo drives via the controller 4, automatic intelligent target finding can be achieved, improving target finding efficiency. For example, during target finding, the laser ranging module 31 projects an emitted laser towards the target and calculates the distance L1 between the projection point and the emission point of the emitted laser. Distance L1 can also be a set value during installation. The controller 4 acquires the distance L1. Based on distance L1, coordinate units (step displacement L2, set according to target size and target finding accuracy), and the rotation arm L4 of the laser ranging module 31 (the distance L between the first drive component 2 and the horizontal axis 22 or the distance between the second drive component 3 and the vertical axis 32), the controller 4 can calculate the output stroke L3 of the miniature servo drive, thereby achieving helical motion of the projection point. As shown in Figure 5, the output stroke L3 of the miniature servo drive is as follows:

[0061] L3 = L2 × L4 / L1

[0062] During the movement of the projection point, the controller 4 collects the field strength and coordinate data of the sampling point 100, and can determine the target area and the center point of the target based on this data, thereby achieving automatic intelligent target finding with high target finding efficiency and high position accuracy.

[0063] In some embodiments, the distance between the first drive component 2 and the horizontal axis 22 is equal to the distance between the second drive component 3 and the vertical axis 32.

[0064] This allows the controller 4 to simultaneously obtain the stroke of the first drive component 2 and the second drive component 3 in a single calculation, saving calculation time and simplifying the calculation process. When the two distances are not equal, the controller 4 needs to calculate the stroke separately and drive the rotation amplitude of the laser ranging module 31 separately.

[0065] The device for implementing the laser target-finding method in this application controls the spiral motion of the projection point of the emitted laser by controlling the rotation of the laser ranging module 31. The controller 4 automatically calculates and controls the single stroke of the micro servo driver to achieve automatic intelligent target-finding. The laser ranging module 31 is rotatably mounted, which is convenient for installation and implementation and occupies little space.

[0066] This application also provides a tunnel monitoring method, as shown in Figure 6, including the following steps:

[0067] On both sides of the tunnel, targets and the implementation device of the laser target finding method provided in the above embodiments of this application are respectively set up. The laser target finding method provided in the embodiments of this application is used to find and locate the target and determine the center point (i.e., the bullseye).

[0068] The laser emitted by the laser ranging module 31 is projected onto the center point of the target;

[0069] The intensity of the reflected light from the emitted laser is collected and compared in real time. If the intensity decreases, it is considered to be off-target, and the tunnel may be deformed.

[0070] Targets and the implementation device of the laser target-finding method provided in the above embodiments of this application can be set on both sides of the tunnel length direction. Targets and the implementation device of the laser target-finding method provided in the above embodiments of this application can also be set on both sides of the tunnel width direction. It is understood that at the initial monitoring moment, the emitted laser from the laser ranging module 31 is projected onto the center point of the target. Over time, if the tunnel deforms, the position of the target will change, and the projection point of the emitted laser on the target will also shift. The intensity detection value of the reflected light from the emitted laser is collected in real time, and the collected intensity detection values ​​are compared. If the intensity detection value of the reflected light decreases, it is considered to have missed the target, indicating that the monitored tunnel may be deformed. When the emitted laser misses the target, the emitted laser can no longer irradiate the reflective coating on the target, the energy loss of the reflected light increases, and the intensity value of the reflected light decreases.

[0071] The tunnel monitoring method provided in this application monitors deformation based on changes in the intensity of reflected light, which has high monitoring accuracy and can achieve real-time monitoring of tunnel deformation, making it safer and more reliable.

[0072] It should be explained that the change in the intensity value of the reflected light may be due to the sudden change in intensity value caused by the displacement of the target, or it may be due to the misjudgment of the target due to accidents such as temporary obstruction. Therefore, in this embodiment, when the intensity value changes, the coordinate value of the sampling point 100 can be further judged. If the field strength value and the coordinate value change at the same time, it is considered that there is a target miss, and the controller 4 can alarm the dispatch center.

Claims

1. Laser target finding methods, including: A laser ranging module (31) and a target are set at intervals on the object being detected; The laser ranging module (31) projects an emitted laser toward the target; A sampling point coordinate system is established with the projection point of the emitted laser as the origin; The projection point of the emitted laser moves in a spiral motion around the origin of the coordinate system in the sampling point coordinate system, and collects the real-time coordinate values ​​of all sampling points (100) in the sampling point coordinate system, as well as the real-time intensity values ​​of the reflected light of the emitted laser at all sampling points (100). After the spiral motion ends, the target area is determined based on the real-time intensity value of the reflected light at all sampling points (100) and the center point of the target is determined based on the coordinate values ​​of all sampling points (100) within the target area.

2. The laser target finding method according to claim 1, wherein, The trajectory of the spiral motion is as follows: starting from the origin of the coordinate system, the projection point moves step by step according to the step displacement. For each step, the projection point rotates 90° toward the origin of the coordinate system, and then moves step by step again. For each step, the displacement value increases by one displacement difference. The trajectory of the step movement is a straight line.

3. The laser target finding method according to claim 2, wherein, The displacement difference is the displacement value of the step displacement when the projection point moves for the first time.

4. The laser target finding method according to claim 2, wherein, The outer diameter of the trajectory of the spiral motion is at least twice the outer diameter of the target.

5. The laser target finding method according to claim 1, wherein, The target is provided with a reflective coating. In response to determining that the emitted laser irradiates the reflective coating, the intensity value of the reflected light from the emitted laser is different from the intensity value of the reflected light from the emitted laser irradiating a non-target location.

6. A device for implementing the laser target-finding method, comprising: A base (1) is provided at a distance from the target; A first drive assembly (2) is disposed on the base (1). The output end of the first drive assembly (2) is provided with a mounting bracket (21). The first drive assembly (2) is configured to drive the mounting bracket (21) to rotate around a horizontal axis (22). The second drive assembly (3) is mounted on the mounting bracket (21), and the laser ranging module (31) is mounted on the mounting bracket (21). The second drive assembly (3) is configured to drive the laser ranging module (31) to rotate around the vertical axis (32).

7. The apparatus for implementing the laser target finding method according to claim 6 further includes a controller (4), the controller (4) being disposed on the base (1), and the controller (4) being communicatively connected to the first drive component (2) and the second drive component (3) respectively.

8. The apparatus for implementing the laser target finding method according to claim 6, wherein, The distance between the first drive component (2) and the horizontal axis (22) is equal to the distance between the second drive component (3) and the vertical axis (32).

9. The apparatus for implementing the laser target finding method according to claim 6, wherein, The first drive component (2) and the second drive component (3) are driven by micro servo drivers respectively.

10. Tunnel monitoring methods, including: On both sides of the tunnel, targets and the implementation device of the laser target finding method according to any one of claims 6-9 are respectively set up. The laser target finding method according to any one of claims 1-5 is used to find and locate the target and determine the center point of the target. The laser emitted by the laser ranging module (31) is projected onto the center point of the target; The intensity of the reflected light from the emitted laser is collected in real time and compared with the collected intensity values. If the intensity value decreases, it is considered as a miss.

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