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

Abstract

This invention belongs to the field of deformation monitoring technology and discloses a laser target-finding method, its implementation device, and a tunnel deformation monitoring method. The laser target-finding method first involves setting a laser ranging module and a target at intervals on the object to be monitored; then, the laser ranging module projects an emitted laser beam towards the target; the projection point of the emitted laser beam serves as the origin to establish a sampling point coordinate system; the projection point of the emitted laser beam is controlled to move in a spiral motion around the origin within the sampling point coordinate system, collecting the real-time intensity and coordinate values ​​of all sampling points in the system; after the spiral motion ends, the target area is determined based on the real-time intensity values ​​of the sampling points, and the center point of the target is determined based on the coordinate values ​​of the sampling points within the target area. This invention improves the initial target-finding efficiency and accuracy, enabling faster monitoring; it achieves automatic and intelligent target-finding, significantly reducing construction time and debugging difficulty, thus reducing manpower and monitoring costs.

Description

Technical Field

[0001] This invention relates to the field of deformation monitoring technology, and in particular to a laser target-finding method and its implementation device, as well as a tunnel deformation monitoring method. Background Technology

[0002] 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.

[0003] 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. Summary of the Invention

[0004] The purpose of this invention is to provide 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.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The first objective of this invention is to provide a laser target finding method, comprising the following steps:

[0007] S1, laser ranging modules and targets are set at intervals on the object being detected;

[0008] S2, the laser ranging module projects an emitted laser toward the target;

[0009] S3, establish a sampling point coordinate system with the projection point of the emitted laser as the origin;

[0010] S4, 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 intensity value and real-time coordinate value of all sampling points in the sampling point coordinate system;

[0011] S5, after the spiral motion ends, the target area is determined based on the real-time intensity value of the sampling point, and the center point of the target is determined based on the coordinate value of the sampling point within the target area.

[0012] In some embodiments, in step S4, 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. After each step, the projection point rotates 90° toward the origin of the coordinate system and then moves stepwise again. After each step, the displacement value of the step displacement increases by one displacement difference, and the trajectory of the step movement is a straight line.

[0013] In some embodiments, the displacement difference is the displacement value of the step displacement when the projection point moves for the first time.

[0014] In some embodiments, the outer diameter of the trajectory of the helical motion is at least twice the outer diameter of the target.

[0015] In some embodiments, the target is provided with a reflective coating, which causes the intensity of the reflected light from the emitted laser on the target to be different from the intensity at non-target locations when the emitted laser irradiates the target.

[0016] A second objective of this invention is to provide an apparatus for implementing a laser target-finding method, comprising:

[0017] A base, wherein the base is disposed at a distance from the target;

[0018] A first drive assembly is disposed on the base, and a mounting bracket is provided at the output end of the first drive assembly. The first drive assembly is used to drive the mounting bracket to rotate around a horizontal axis.

[0019] The second drive assembly is disposed on the mounting bracket, on which the laser ranging module is mounted. The second drive assembly is used to drive the laser ranging module to rotate around a vertical axis.

[0020] 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.

[0021] 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.

[0022] In some embodiments, both the first drive component and the second drive component are miniature servo drivers.

[0023] A third objective of this invention is to provide a tunnel monitoring method, comprising the following steps:

[0024] Targets and the implementation device of the laser target finding method provided by the present invention are set on both sides of the tunnel. The laser target finding method provided by the present invention is used to find and locate the target and determine the center point of the target.

[0025] The laser emitted by the laser ranging module is projected onto the center point of the target;

[0026] The intensity of the reflected light from the emitted laser is collected and compared in real time. If the intensity value decreases, it is considered to be off-target, and the tunnel may be deformed.

[0027] The beneficial effects of this invention are:

[0028] The laser target-finding method provided by this invention locates the target based on the intensity change of the reflected light from the emitted laser beam. The projection point of the emitted laser beam is used as the origin to establish a sampling point coordinate system. The trajectory of the projection point is controlled to move in a spiral motion within the sampling point coordinate system. When the spiral trajectory covers the target area, the target area can be determined based on the intensity value of the reflected light from the emitted laser beam. The coordinate values ​​of the sampling points within the target area can determine the center point of the target, thus achieving automatic laser target finding. This laser target-finding method can improve the initial target-finding efficiency and accuracy of the monitoring process, allowing for faster commencement of the monitoring process. This invention achieves automatic and intelligent target finding, significantly reducing construction time and debugging difficulty, and helping to reduce manpower expenditure and monitoring costs.

[0029] The device for implementing the laser target finding method of the present invention controls the spiral motion of the projection point of the emitted laser by controlling the rotation of the laser ranging module. It is easy to install and implement, occupies little space, and is conducive to realizing automatic intelligent target finding.

[0030] The tunnel monitoring method provided by this invention monitors deformation based on changes in the intensity of reflected light, which has the advantages of high monitoring accuracy and can realize real-time monitoring of tunnel deformation, making it safer and more reliable. Attached Figure Description

[0031] Figure 1 This is a flowchart of the laser target finding method provided in the embodiments of the present invention;

[0032] Figure 2 This is a schematic diagram showing the correspondence between the trajectory of the spiral motion in the laser target finding method provided in this embodiment of the invention and the coordinate system of the sampling point;

[0033] Figure 3 This is a schematic diagram of the structure of the device for implementing the laser target finding method provided in an embodiment of the present invention;

[0034] Figure 4 This is a side view of the device for implementing the laser target finding method provided in an embodiment of the present invention;

[0035] Figure 5 This 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 this embodiment of the invention.

[0036] Figure 6 This is a flowchart of the tunnel monitoring method provided in an embodiment of the present invention.

[0037] In the picture:

[0038] 100. Sampling points;

[0039] 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

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0041] In the description of this invention, unless otherwise explicitly 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 invention based on the specific circumstances.

[0042] In this invention, unless otherwise explicitly 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 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 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.

[0043] 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 the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0044] like Figures 1-6 This invention provides a laser target finding method and its implementation device, as well as a method for detecting tunnel deformation using the laser target finding method and its implementation device.

[0045] like Figure 1 The laser target-finding method, as shown in the flowchart, includes the following steps:

[0046] S1, laser ranging module 31 and target are set at intervals on the object to be detected;

[0047] S2, the laser ranging module 31 projects the emitted laser toward the target;

[0048] S3, establish the sampling point 100 coordinate system with the projection point of the emitted laser as the origin;

[0049] 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 intensity value and real-time coordinate value of all sampling points 100 in the coordinate system of sampling point 100.

[0050] S5. After the spiral motion ends, the target area is determined based on the real-time intensity value of sampling point 100, and the center point of the target is determined based on the coordinate values ​​of sampling point 100 within the target area.

[0051] The laser target-finding method provided by this invention can be used to locate 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 locate 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, allowing for faster commencement of the monitoring process. This invention achieves 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, that is, the target area can be traversed by the helical motion. If the trajectory of the helical motion 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.

[0052] 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. After each step, the projection point rotates 90° toward the origin of the coordinate system and then moves step by step again. After each step, the displacement value increases by one displacement difference. The trajectory of the step movement is a straight line.

[0053] like Figure 2 As shown, the trajectory of the helical 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 parallel or perpendicular to the coordinate axis at each coordinate unit, intersection points (or grid points) are formed. Multiple intersection points are defined as sampling point 100. Figure 2(The black nodes in the diagram). In this embodiment, a rectangular target is used as an example. The target size is 5cm × 5cm, and the size of the spiral motion trajectory is 10cm × 10cm. By controlling the projection point to move linearly according to the step displacement, the initial step displacement of the projection point is to move one coordinate unit along the positive Y-axis, then rotate 90° to the right to change the direction of movement to the positive X-axis, continue to move one coordinate unit, and then rotate 90° towards the origin O, i.e., towards the negative Y-axis. After the above two step movements, the step displacement increases by a 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 then 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, it is easier to find the target position within the gradually expanding spiral area. Moreover, the projection point moves linearly within the sampling point 100 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.

[0054] In some embodiments, the displacement difference is the displacement value of the step displacement when the projection point moves for the first time.

[0055] In this embodiment, the displacement difference is one coordinate unit, such as Figure 2 The initial step displacement is 1cm, the coordinate unit is set to 1cm, the projection point moves twice every step, and the coordinate unit is increased by one. If a spiral motion trajectory with uniform intervals is achieved, it will be beneficial to calculate and determine the position of the target.

[0056] In some embodiments, the outer diameter of the trajectory of the helical motion is at least twice the outer diameter of the target.

[0057] 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 outer diameter of the target. When the emission point is outside the target area, the spiral motion trajectory must be at least twice the outer diameter of the target. This allows the spiral motion trajectory to cover as much of the target area as possible, thereby improving the accuracy of determining the target's center point. Figure 2As shown, when the origin O is exactly outside the target, after the projection point completes the spiral motion, the target area (shown by the dotted line in the figure) is exactly within the trajectory of the spiral motion. 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 projection point of the emitted laser is adjusted to be located at the center point of the target to complete the target finding process, allowing for subsequent real-time monitoring. It can be understood that the trajectory of the spiral motion can be adjusted based on the real-time intensity and coordinate values ​​collected during the projection point's movement. The initial projection point of the emitted laser can also be determined using the laser target finding method provided by this invention, thereby obtaining the target position within a defined trajectory. This helps reduce or minimize the travel of the laser ranging module 31 when controlling the projection point position, saving installation space.

[0058] In some embodiments, the target is provided with a reflective coating, which causes the intensity of the reflected light from the emitted laser on the target to be different from the intensity at non-target locations when the emitted laser irradiates the target.

[0059] 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.

[0060] The device for implementing the laser target finding method provided in this embodiment of the invention includes a base 1, a first driving component 2, and a second driving component 3. The base 1 is arranged at a distance from the target. 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 used 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 used to drive the laser ranging module 31 to rotate around a vertical axis 32.

[0061] like Figure 3 and Figure 4As shown, 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 is set 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 other end is rotatably connected to the vertical plate of the base 1 through the 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 set on the mounting bracket 21. One end of the laser ranging module 31 is rotatably connected to the mounting bracket 21 through the vertical shaft 32, and the other end 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 invention 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.

[0062] 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.

[0063] 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. Specifically, 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 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. Figure 5 As shown, the output travel L3 of the micro servo driver is as follows:

[0064] L3 = L2 × L4 / L1

[0065] 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.

[0066] 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.

[0067] 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.

[0068] The device for implementing the laser target finding method of the present invention controls the helical 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.

[0069] This invention also provides a tunnel monitoring method, such as... Figure 6 It includes the following steps:

[0070] On both sides of the tunnel, targets and the implementation device of the laser target finding method provided in the above embodiment of the present invention are respectively set up. The laser target finding method provided in the embodiment of the present invention is used to find and locate the target and determine the center point (i.e. the bullseye).

[0071] The laser emitted by the laser ranging module 31 is projected onto the center point of the target;

[0072] 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.

[0073] The tunnel monitoring method provided by this invention monitors deformation based on changes in the intensity of reflected light, which has the advantages of high monitoring accuracy and can realize real-time monitoring of tunnel deformation, making it safer and more reliable.

[0074] 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 of the invention, after 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.

[0075] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A tunnel monitoring method, characterized in that, Includes the following steps: S1, laser ranging modules (31) and targets are set at intervals on the tunnel; S2, the laser ranging module (31) projects an emitted laser toward the target; S3, establish a sampling point (100) coordinate system with the projection point of the emitted laser as the origin; S4, the projection point of the emitted laser moves in a spiral motion around the origin in the coordinate system of the sampling point (100) to collect the real-time intensity value and real-time coordinate value of all sampling points (100) in the coordinate system of the sampling point (100); 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. After each step, the projection point rotates 90° toward the origin of the coordinate system and then moves step by step again. After each step, the displacement value of the step displacement increases by one displacement difference. The trajectory of the step movement is a straight line. S5, after the spiral motion ends, the area of ​​the target is determined according to the real-time intensity value of the sampling point (100), and the center point of the target is determined according to the coordinate value of the sampling point (100) within the target area; S6, the laser emitted by the laser ranging module (31) is projected onto the center point of the target; S7. The intensity detection value of the reflected light of the emitted laser is collected in real time and compared. If the intensity detection value decreases, it is considered to be off-target. The outer diameter of the trajectory of the spiral motion is at least twice the outer diameter of the target; the target is provided with a reflective coating, and when the emitted laser irradiates the target, the reflective coating makes the intensity value of the reflected light of the emitted laser on the target different from the intensity value at the non-target position.

2. The tunnel monitoring method according to claim 1, characterized in that, The displacement difference is the displacement value of the step displacement when the projection point moves for the first time.

3. An apparatus for implementing the tunnel monitoring method according to any one of claims 1-2, characterized in that, include: A base (1) is provided at a distance from the target; the target is provided with a reflective coating, and when the emitted laser irradiates the target, the reflective coating makes the intensity value of the reflected light of the emitted laser on the target different from the intensity value at the non-target position; 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 used 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 used to drive the laser ranging module (31) to rotate around the vertical axis (32).

4. The implementing apparatus according to claim 3, characterized in that, It also includes a controller (4), which is mounted on the base (1) and is communicatively connected to the first drive component (2) and the second drive component (3).

5. The implementing apparatus according to claim 3, characterized in that, 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).

6. The implementing apparatus according to claim 3, characterized in that, Both the first drive component (2) and the second drive component (3) are micro servo drivers.

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