A deep coal mine rock wall laser displacement monitoring device

Abstract

The present application relates to the technical field of laser monitoring, and more particularly to a deep coal mine rock wall laser displacement monitoring device. It comprises a laser ranging module and a plurality of installation tubes. The side close to the laser ranging module of the installation tube is fixedly connected with a main end cover. The installation tube is provided with a reflecting disc and is fixedly connected with a photoelectric sensor and a control power module. The side away from the adjacent main end cover of the installation tube is fixedly connected with a secondary end cover. The secondary end cover is provided with a traction member. The traction member and the adjacent installation tube on the side away from the laser ranging module are jointly fixedly connected with a steel wire rope. The present application connects two adjacent targets by means of the steel wire rope. When a target loses signal due to deviation, the steel wire rope transmits the deviation information to the adjacent target. The information obtained by the target knows the situation of the target that loses signal, eliminates the interference signal caused by the line of sight obstruction and dust, and is beneficial to the normal progress of the project.

Description

Technical Field

[0001] This invention relates to the field of laser monitoring technology, and more specifically to a laser displacement monitoring device for deep coal mine rock walls. Background Technology

[0002] As a fundamental energy source, the safe, efficient, green, and intelligent mining of coal is of paramount importance. Currently, integrating artificial intelligence technology into coal mine construction is driving mining towards automation, unmanned operation, and intelligence. During tunneling, the working face disturbs the stable structure of the surrounding rock, causing deformation and leading to disasters such as roof falls, floor heave, and sidewall displacement, threatening safe production. To address these issues, existing technologies can be used to monitor the deformation of the surrounding rock in real time, accurately grasp its changes, provide timely warnings of the extent of damage, and offer decision-making support for roadway support, thereby ensuring safe and efficient operations and creating a safe environment for intelligent tunneling.

[0003] The commonly used traditional roadway monitoring technology in coal mines is laser displacement monitoring. This technology involves installing reflective targets at key locations on the roadway roof, sides, and floor (such as deformation-sensitive areas and geological structural zones), and deploying laser rangefinders in relatively stable areas to align with the targets, forming a monitoring network. Roadway deformation is determined by measuring changes in the distance between the laser rangefinder and the targets, triggering an alarm. However, when significant displacement of the surrounding rock causes the targets to move, or when the line of sight is obstructed or interfered with by dust, the target signal may be lost. The system cannot distinguish the specific cause of the signal loss (whether it is severe displacement or interference fault), and once the signal is lost, an alarm is triggered immediately, requiring workers to evacuate. This often results in workers making futile trips back and forth, delaying the project and reducing the reliability of the alarm system. Summary of the Invention

[0004] The purpose of this invention is to provide a laser displacement monitoring device for deep coal mine rock walls, so as to overcome the shortcomings of current coal mine rock wall monitoring technology, which cannot determine the cause of signal loss, causing workers to make futile trips and delaying the progress of the project.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A laser displacement monitoring device for deep coal mine rock walls includes: a laser ranging module and several mounting cylinders. A main end cap is fixed to the side of each mounting cylinder closest to the laser ranging module. A reflector is installed inside each mounting cylinder, and a photoelectric sensor and a control power module are fixedly connected thereto. A secondary end cap is fixed to the side of each mounting cylinder away from the adjacent main end cap. A traction component is provided on the secondary end cap. A steel wire rope is fixedly connected between the traction component and the adjacent mounting cylinder on the side away from the laser ranging module. A trigger bar is fixed to the traction component. A strip-shaped groove is provided on the secondary end cap, and a trigger switch is installed within the groove. The trigger bar is engaged within the groove and contacts the trigger switch. The photoelectric sensor, the control power module, and the trigger switch within the same mounting cylinder are sequentially electrically connected. A feedback component for feeding information back to the laser ranging module and a fixing component for fixing the module to the roadway rock wall are provided within each mounting cylinder.

[0006] Furthermore, the feedback component includes a mounting bracket and a servo motor. The mounting bracket is fixed to the side of the main end cover near the reflector. The servo motor is fixed to the mounting bracket. The control power module is electrically connected to the servo motor. The output shaft of the servo motor is fixed to the reflector. The reflector has a reflective coating on its outer side near the main end cover.

[0007] Furthermore, within the same central angle corresponding to the end face of the reflector, circles concentric with the end face of the reflector but with different radii all have two intersection points with the aforementioned central angle, and the difference in light reflectivity corresponding to the two intersection points on any one of the aforementioned circles is the same.

[0008] Furthermore, the fixing component includes: a ball head, a fixing seat, and a fastening nut. The ball head is fixedly connected to the mounting cylinder, and the ball head is ball-jointed with the fixing seat. The fixing seat is used to anchor to the surface of the tunnel rock wall, and the fastening nut is threadedly connected to the fixing seat. The fastening nut is used to compress the deformation of the fixing seat.

[0009] Furthermore, the secondary end cap is provided with a sliding groove, within which a sliding component is slidably and rotatably connected. A rubber ring is fixedly connected to the sliding component, and the rubber ring contacts the sliding groove with friction between them. A color film is fixedly connected to the sliding component, and the side of the color film away from the adjacent sliding component passes through the strip groove and is fixedly connected to a clamping strip. The trigger strip is slidably connected to the clamping strip, and an elastic strip is fixedly connected between the clamping strip and the traction component. An installation strip is fixedly connected to the side of the secondary end cap near the adjacent main end cap, and a color sensor is mounted on the installation strip. The color sensor is electrically connected to the control power module.

[0010] Furthermore, the frictional force between the rubber ring and the sliding groove is greater than the yield load of the elastic strip, and the yield load of the elastic strip is greater than the traction force brought by the self-weight of the adjacent wire rope.

[0011] Furthermore, the color film is fan-shaped, and the center of the side of the color film is located on the central axis of the sliding member.

[0012] Furthermore, the long edges of the groove are all horizontal.

[0013] Furthermore, the mounting strip contacts the color film to keep the color film flat.

[0014] Furthermore, the mounting strip is provided with a receiving groove.

[0015] The beneficial technical effects of this invention are: This invention uses steel wire ropes to connect two adjacent targets. When a target loses its signal due to displacement, the steel wire ropes transmit the displacement information to the adjacent target. This allows the information obtained from the target to indicate the target where the signal is lost, eliminating interference signals caused by obstructed vision or dust, and helping to maintain the normal progress of the project.

[0016] By rotating the reflector disk to change the reflectivity of the target to the laser, the intensity of the reflected laser light received by the laser ranging module changes when measuring the distance to the same target. This transmits the offset information of adjacent targets to the laser ranging module, enabling the laser ranging module to issue a corresponding alarm based on the received information.

[0017] By sensing the color change of the color film through a color sensor, the direction and distance of the color film's offset can be determined. The offset information is then transmitted to the laser ranging module through the rotational speed change of the reflector. This completes the data on the deformation of the tunnel rock wall, providing more solid data support for personnel evacuation and tunnel reinforcement. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the mounting cylinder and photoelectric sensor of the present invention; Figure 3 This is a three-dimensional structural diagram of the reflector and mounting base of the present invention; Figure 4 This is a three-dimensional structural diagram of the secondary end cap and the traction component of the present invention; Figure 5 This is a three-dimensional structural diagram of the trigger strip and color film of the present invention; Figure 6 This is a three-dimensional structural cross-sectional view of the sliding component and color film of the present invention; Figure 7 Appendix to this invention Figure 6 Enlarged view of point A in the middle; Figure 8 This is an exploded view of the main end cap, reflector disk, and secondary end cap of the present invention; Figure 9 This is a three-dimensional structural diagram of the mounting strip and color sensor of the present invention.

[0019] In the attached diagram, the following are the reference numerals: 1. Laser ranging module; 2. Mounting cylinder; 3. Main end cap; 4. Reflector; 5. Photoelectric sensor; 6. Control power module; 7. Secondary end cap; 701. Strip groove; 8. Traction component; 9. Trigger bar; 10. Trigger switch; 11. Mounting bracket; 12. Servo motor; 13. Ball head; 14. Fixing base; 15. Fastening nut; 16. Sliding component; 161. Sliding groove; 17. Rubber ring; 18. Color film; 19. Clamping bar; 20. Elastic bar; 21. Mounting bar; 211. Receiving groove; 22. Color sensor. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Certain embodiments of the invention will be described more fully below with reference to the accompanying drawings, and some, but not all, of these embodiments will be shown. In fact, various embodiments of the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the invention to meet applicable legal requirements.

[0021] In the description of this invention, it should be noted that the terms "inner," "outer," "upper," "lower," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, 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 invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] Example 1 This embodiment discloses a laser displacement monitoring device for deep coal mine rock walls to identify the cause of target signal loss and reduce the probability of workers making futile round trips and slowing down the progress of the project.

[0023] See Figures 1 to 7A laser displacement monitoring device for deep coal mine rock walls includes: a laser ranging module 1 and several mounting cylinders 2. The laser ranging module 1 has the functions of emitting and receiving laser light and detecting the intensity of the received laser light. The laser ranging module 1 is fixed to the rock wall of the roadway by anchoring. The laser ranging module 1 can change the laser emission angle in the up-down and left-right directions to correspond to multiple targets. A main end cap 3 is fixed to the right side of the mounting cylinder 2. (See...) Figure 1 The upper part of the main end cap 3 is provided with a light-transmitting hole. The mounting cylinder 2 is equipped with a reflector 4 and a photoelectric sensor 5 and a control power module 6 are fixedly connected to it. (See...) Figure 3 The outer periphery of the right side of the reflector 4 is provided with a ring-shaped reflective coating, which is a glass microsphere coating. A secondary end cap 7 is fixed to the left side of the mounting cylinder 2. A traction component 8 is provided to the left of the secondary end cap 7. A steel wire rope is fixed to the traction component 8 and the adjacent mounting cylinder 2 on its left side. A trigger bar 9 is fixed to the traction component 8. A strip groove 701 is provided at the lower part of the secondary end cap 7. A trigger switch 10 is installed in the strip groove 701. The trigger bar 9 is stuck in the strip groove 701 and contacts the trigger switch 10, so that the circuit composed of the trigger switch 10, photoelectric sensor 5 and control power module 6 is kept in an open state. The photoelectric sensor 5, control power module 6 and trigger switch 10 in the same mounting cylinder 2 are electrically connected in sequence. A feedback component for feeding back information to the laser ranging module 1 is provided in the mounting cylinder 2. A fixing component for fixing it to the tunnel rock wall is provided in the mounting cylinder 2.

[0024] The above setup enables the connection of two adjacent targets using steel wire ropes. In this way, if a target loses its signal due to displacement, the displacement information can be transmitted to the adjacent target via the steel wire rope. This allows the information obtained from the target to indicate the location of the lost signal, eliminating interference signals caused by obstructed vision or dust, and helping to maintain the normal progress of the project.

[0025] It should be noted that in this embodiment, the force required for the trigger bar 9 to detach from the strip groove 701 is greater than the traction force brought by the weight of the wire rope itself. This purpose can be achieved by controlling the magnitude of the friction between the trigger bar 9 and the strip groove 701.

[0026] See Figure 2 and Figure 3The feedback components include: a mounting bracket 11 and a servo motor 12. The mounting bracket 11 is fixed to the left side of the main end cover 3, and the servo motor 12 is fixed to the mounting bracket 11. The control power module 6 is electrically connected to the servo motor 12. When the photoelectric sensor 5 receives the light signal, the control power module 6 is electrically connected to the servo motor 12. The output shaft of the servo motor 12 is fixed to the reflector 4. Within the same central angle corresponding to the end face of the reflector 4, circles concentric with the end face of the reflector 4 and with different radii all have two intersection points with the aforementioned central angle, and the light reflectivity difference corresponding to the two intersection points on any of the aforementioned circles is the same.

[0027] The above settings enable the target's reflectivity to the laser to be changed by rotating the reflector disk 4. This means that when the laser ranging module 1 measures the distance to the same target, the intensity of the reflected laser light received by the laser ranging module 1 changes. In this way, the offset information of adjacent targets is transmitted to the laser ranging module 1, so that the laser ranging module 1 issues a corresponding alarm based on the received information.

[0028] See Figures 1 to 3 The fixing assembly includes a ball head 13, a fixing seat 14, and a fastening nut 15. The ball head 13 is fixedly connected to the mounting cylinder 2, and the ball head 13 is ball-jointed with the fixing seat 14. The ball joint between the fixing seat 14 and the ball head 13 is provided with a ring-shaped, evenly distributed notch. The fixing seat 14 is used to anchor to the surface of the tunnel rock wall. The fastening nut 15 is threadedly connected to the fixing seat 14. The left side of the fixing seat 14 is provided with a threaded groove, and the outer diameter of the left side of the fixing seat 14 gradually increases from front to back, so that the fastening nut 15 can retract inward through the threaded drive of the left side of the fixing seat 14.

[0029] Rock wall displacement monitoring process: Based on the length of the tunnel and the condition of the rock wall, the staff determines the distance between adjacent targets (the entire assembly consisting of the installation cylinder 2 and all its parts is referred to as the target in this article). During actual installation, all targets are anchored on one side of the tunnel, and the laser ranging module 1 is anchored above the same side of the tunnel. The orientation of the targets is adjusted so that the laser emitted by the laser ranging module 1 can illuminate all targets.

[0030] The process for adjusting the target orientation is as follows: The operator rotates the fastening nut 15, causing the fastening nut 15 to move forward relative to the fixed seat 14, thereby reducing the squeezing force of the fixed seat 14 on the ball head 13. At this time, the angle of the mounting cylinder 2 is swung so that the laser emitted from the laser ranging module 1 illuminates the center point of the light-transmitting hole on the main end cover 3. At this time, the position of the mounting cylinder 2 remains unchanged, and the fastening nut 15 is rotated in the opposite direction. The fastening nut 15 is used to retract the front part of the fixed seat 14 inward, increasing the squeezing force of the fixed seat 14 on the ball head 13. Then, the friction between the ball head 13 and the fixed seat 14 is used to fix the position of the mounting cylinder 2. This completes the process of adjusting the target orientation.

[0031] During routine monitoring, the laser ranging module 1 periodically and individually measures the distance between itself and all targets. By observing the changes in the distance, the movement of the rock wall at the target corresponding to that distance is determined. The specific distance measurement steps are as follows: The laser ranging module 1 automatically adjusts to the angle corresponding to the target. Then, the laser ranging module 1 simultaneously emits multiple laser segments (the number of laser segments is greater than or equal to two). After receiving the laser, the reflector 4 of the corresponding target reflects the laser back, so that the laser ranging module 1 receives the reflected laser. The distance between the two is measured based on the time interval between the emission and reception of the laser.

[0032] If one of the targets shifts and cannot receive and reflect the laser (the shifted target will be named the first target), during the target shifting process, the traction member 8 on the adjacent target to its right (the target to be pulled will be named the second target) will be moved by the steel wire rope. The traction member 8 will drive the trigger bar 9 to move. Before the trigger bar 9 moves out of the strip groove 701, the first target can still receive the laser. In this state, the trigger bar 9 of the second target is still in contact with the trigger switch 10. After the trigger bar 9 moves out of the strip groove 701, the first target can no longer receive the laser, and the trigger bar 9 of the second target loses contact with the trigger switch 10. At this time, the trigger switch 10 closes the circuit and electrically connects the photoelectric sensor 5 and the control power module 6.

[0033] When the laser ranging module 1 measures the distance between itself and the second target, the laser emitted by the laser ranging module 1 reaches the surface of the reflector disk 4. After reflection and refraction by the reflector disk 4, part of the laser is reflected back, and the other part is refracted to the photoelectric sensor 5, causing the photoelectric sensor 5 to receive a signal. The photoelectric sensor 5 controls the servo motor 12 to rotate, and the output shaft of the servo motor 12 drives the reflector disk 4 to rotate at a constant speed. This causes a change in the light reflectivity of the position corresponding to the light-transmitting hole on the main end cover 3 of the reflector disk 4, so that the light intensity of the reflected laser received by the laser ranging module 1 gradually decreases. In this way, the laser ranging module 1 can determine that the first target adjacent to the left of the second target has shifted and issue an alarm in time to remind the staff in the tunnel to evacuate in time. At the same time, knowing the reason for the loss of the target signal makes it easier for the staff to remedy the tunnel problem corresponding to the point of signal loss.

[0034] Example 2 This embodiment is a further optimization based on Embodiment 1.

[0035] See Figures 4 to 9The secondary end cap 7 is provided with a sliding groove 161. A sliding member 16 is rotatably connected within the sliding groove 161 and is limited in sliding. A rubber ring 17 is fixed to the sliding member 16. The rubber ring 17 contacts the sliding groove 161 and there is friction between them. A colored film 18 is fixed to the sliding member 16. The colored film 18 is fan-shaped, and the center of the side of the colored film 18 is located on the central axis of the sliding member 16. The colored film 18 is a thin metal sheet, so that the colored film 18 will not wrinkle due to local elastic deformation when subjected to the tensile force applied by the sliding member 16 and the clamping strip 19, keeping the surface of the colored film 18 flat. The colors of different parts of the side of the colored film 18 are different, so that the offset angle and movement distance of the colored film 18 can be judged by the local color of the colored film 18. The lower side of the colored film 18 passes through the strip groove 701 and is fixed to the clamping strip 19. The trigger strip 9 and the clamping strip 19 limit the sliding. The right side of the trigger strip 9 is a double-layer structure formed by folding and bonding, which prevents the right side of the trigger strip 9 from passing over the clamping strip 19. An elastic strip 20 is fixed between the clamping strip 19 and the traction member 8. The elastic strip 20 is a polyethylene sheet, meaning that the elastic deformation of the elastic strip 20 is small, but it can undergo large-scale plastic tensile deformation. The friction between the rubber ring 17 and the sliding groove 161 is greater than the yield load of the elastic strip 20, and the yield load of the elastic strip 20 is greater than the traction force brought by the self-weight of the adjacent steel wire rope. An installation strip 21 is fixed to the right side of the secondary end cap 7. A color sensor 22 is installed on the installation strip 21. The control power module 6 is electrically connected to the color sensor 22. The fan shape of the color film 18 enables it to maintain its position corresponding to the color sensor 22 not only during unidirectional sliding, but also after displacement.

[0036] The above settings enable the color sensor 22 to detect the color change of the color film 18, thereby knowing the offset direction and offset distance of the color film 18. The offset information is then transmitted to the laser ranging module 1 through the rotation speed change of the reflector 4. This completes the data on the deformation of the tunnel rock wall, providing more solid data support for personnel evacuation and tunnel reinforcement.

[0037] See Figure 4 and Figure 5 The long edge of the strip groove 701 is adjusted to a horizontal state during installation so that the offset of the color film 18 within the strip groove 701 is not affected by the strip groove 701.

[0038] See Figure 5 and Figure 9 The mounting strip 21 contacts the color film 18 to keep the color film 18 flat. The mounting strip 21 is provided with a receiving groove 211. The detection position of the color sensor 22 is located in the receiving groove 211. The receiving groove 211, the color film 18 and the color sensor 22 cooperate to form a space to reduce the influence of external light on the detection result of the color sensor 22.

[0039] The feedback process after target deviation is as follows: During the deviation of the first target, the traction member 8 on the adjacent second target is moved by the steel wire rope. The traction member 8 drives the trigger strip 9 to move, and at the same time stretches the elastic strip 20. During this process, the sliding member 16, the color film 18 and the clamping strip 19 remain stationary under the action of friction between the rubber ring 17 and the sliding groove 161. When the double-layer part of the trigger strip 9 contacts the clamping strip 19, the trigger strip 9 loses contact with the trigger switch 10. The trigger switch 10 closes the circuit, so that the photoelectric sensor 5 is electrically connected to the control power module 6. The trigger strip 9 can no longer move relative to the clamping strip 19. The traction member 8 pulls the color film 18 to move through the trigger strip 9 and the clamping strip 19, so that the color film 18 drives the sliding member 16 and the rubber ring 17 to move.

[0040] During the movement of the traction color film 18, if the first target moves downward due to the slippage and settlement of the corresponding rock wall, the angle of the steel wire rope relative to the secondary end cap 7 on the horizontal plane remains unchanged, and the color film 18 is simply pulled outward; if the first target moves horizontally due to the extrusion of coal from the two sides of the corresponding rock wall, the angle of the steel wire rope relative to the secondary end cap 7 on the horizontal plane continuously changes, and the color film 18 is pulled outward accompanied by an angle change; during the movement of the color film 18, the position of the color sensor 22 corresponding to the color film 18 continuously changes, causing the color of the color film 18 and the position of the color sensor 22 to continuously change.

[0041] When the laser ranging module 1 emits a laser towards the second target, the photoelectric sensor 5 receives the light signal and activates the color sensor 22 through the control power module 6. The color sensor 22 identifies the color of the corresponding color film 18 at this time. The control power module 6 determines the length and offset angle of the color film 18 that has been pulled away based on the color identified by the color sensor 22, and controls the rotation speed of the servo motor 12 based on the information of the color film 18. In this way, the light intensity of the multiple laser segments emitted by the laser ranging module 1 changes sequentially after being reflected by the reflector 4, and the light intensity change amplitude of adjacent laser segments is consistent. When the laser ranging module 1 receives the reflected laser, it can know the movement information of the color film 18 based on the light intensity change amplitude of adjacent reflected laser segments. In this way, it determines the offset angle and amplitude of the first target, thereby judging the condition of the tunnel rock wall and issuing an appropriate alarm.

[0042] The present invention has been described in detail above with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the laser displacement monitoring device for deep coal mine rock walls according to the present invention. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser displacement monitoring device for deep coal mine rock walls, characterized in that, include: The system comprises a laser ranging module and several mounting cylinders. A main end cap is fixed to the side of each mounting cylinder closest to the laser ranging module. A reflector is installed inside each mounting cylinder, and a photoelectric sensor and a control power module are fixedly connected thereto. A secondary end cap is fixed to the side of each mounting cylinder furthest from the adjacent main end cap. A traction component is installed on the secondary end cap. A steel wire rope is fixedly connected between the traction component and the adjacent mounting cylinder furthest from the laser ranging module. A trigger bar is fixed to the traction component. A strip-shaped groove is provided on the secondary end cap, and a trigger switch is installed within the groove. The trigger bar is engaged within the groove and contacts the trigger switch. The photoelectric sensor, the control power module, and the trigger switch within the same mounting cylinder are sequentially electrically connected. The mounting cylinder contains a feedback component for transmitting information to the laser ranging module and a fixing component for securing it to the tunnel wall. The feedback component includes a mounting bracket and a servo motor. The mounting bracket is fixed to the side of the main end cover near the reflector. The servo motor is fixed to the mounting bracket. The control power module is electrically connected to the servo motor. The output shaft of the servo motor is fixed to the reflector. The reflector is provided with a reflective coating on the outside of the side of the main end cover near the main end cover. The secondary end cap is provided with a sliding groove, and a sliding component is rotatably connected within the sliding groove. A rubber ring is fixed to the sliding component, and the rubber ring contacts the sliding groove with friction between them. A color film is fixed to the sliding component, and the side of the color film away from the adjacent sliding component passes through the strip groove and is fixed to a clamping strip. The trigger strip is slidably connected to the clamping strip, and an elastic strip is fixed between the clamping strip and the traction component. An installation strip is fixed to the side of the secondary end cap near the adjacent main end cap, and a color sensor is installed on the installation strip. The color sensor is electrically connected to the control power module.

2. The laser displacement monitoring device for deep coal mine rock walls according to claim 1, characterized in that, Within the same central angle corresponding to the end face of the reflector, circles concentric with the end face of the reflector but with different radii all have two intersection points with the aforementioned central angle, and the difference in light reflectivity corresponding to the two intersection points on any one of the aforementioned circles is the same.

3. The laser displacement monitoring device for deep coal mine rock walls according to claim 1, characterized in that, The fixing component includes: The device comprises a ball head, a fixed seat, and a fastening nut. The ball head is fixedly connected to the mounting cylinder and ball-jointed with the fixed seat. The fixed seat is used to anchor the device to the surface of the tunnel rock wall. The fastening nut is threadedly connected to the fixed seat and is used to compress the fixed seat to deform.

4. The laser displacement monitoring device for deep coal mine rock walls according to claim 1, characterized in that, The frictional force between the rubber ring and the sliding groove is greater than the yield load of the elastic strip, and the yield load of the elastic strip is greater than the traction force brought by the self-weight of the adjacent wire rope.

5. The laser displacement monitoring device for deep coal mine rock walls according to claim 1, characterized in that, The color film is fan-shaped, and the center of the side of the color film is located on the central axis of the sliding member.

6. The laser displacement monitoring device for deep coal mine rock walls according to claim 1, characterized in that, The long edges of the groove are all horizontal.

7. The laser displacement monitoring device for deep coal mine rock walls according to claim 1, characterized in that, The mounting strip contacts the color film to keep the color film flat.

8. A laser displacement monitoring device for deep coal mine rock walls according to claim 7, characterized in that, The mounting strip is provided with a receiving groove.

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