On-line monitoring system and method for filling roof contact based on laser ranging

Abstract

The invention discloses a filling roof contact online monitoring system and method based on laser ranging, and belongs to the field of filling mining, and the system comprises the following steps: laser ranging, a filling device and a monitoring control module; wherein the laser ranging is used for carrying an airborne laser scanning system and a laser ranging system to scan and obtain the height of a top plate and a bottom plate and the form data of a top plate of a goaf; the monitoring control module is used for dynamically generating a filling rate-roof gap relation curve based on the roof and floor height and roof form data of the goaf; the filling device is used for conducting intelligent filling based on the filling rate-roof gap relation curve. According to the filling roof contact online monitoring system based on laser ranging, the height of the filling body is monitored in real time through the laser ranging device, the filling speed and flow are adjusted at any time, and over-filling or insufficient filling is prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of filling mining, and particularly relates to an on-line monitoring system and method for filling roof contact based on laser ranging. Background Art

[0002] The mined-out areas formed after the exploitation of mineral resources are prone to problems such as surface subsidence and rock bursts, which makes the filling mining method that is safe, environmentally friendly, economical and efficient an inevitable choice. As the core branch of the artificial support mining method, the filling method mainly includes three categories: dry filling, hydraulic filling and cemented filling. Among them, cemented filling has become the mainstream process in the industry due to its advantages such as rapid solidification, high structural strength and simple process. During the specific mining process, the degree of dense roof contact of the filling body is directly related to the stope safety and production efficiency - the higher the roof contact rate, the more conducive it is to the treatment of the mined-out area and the mining operation of adjacent ore bodies.

[0003] During the traditional roof contact filling stage, due to the limitation of space closure, it is impossible for personnel to conduct on-site observations. Conventional drilling verification and empirical judgment are prone to filling volume deviation, which not only poses the risk of roof instability but also causes resource waste. Especially for mined-out areas with complex roof shapes and irregular concave and convex surfaces, the difficulty of accurate roof contact doubles. In addition, the secondary settlement phenomenon generated after the filling body dehydrates and solidifies further highlights the necessity of a dynamic monitoring system. These series of technical pain points urgently need to be systematically solved through innovative monitoring means.

[0004] The prior art has proposed the fiber optic stress sensing technology to improve the accuracy of real-time monitoring of filling roof contact. However, there are also some deficiencies. On the one hand, the sensor accuracy and stability problems may affect the accuracy and stability of the fiber optic stress sensor in roof contact filling monitoring; on the other hand, in some fiber Bragg grating sensors, due to the absorption of a part of the energy by the epoxy resin, there is a transfer error in the strain of the fiber Bragg grating sensor, which is prone to cause strain lag, especially causing a large error in dynamic measurement. Therefore, the present invention proposes an on-line monitoring system and method for filling roof contact based on laser ranging. Summary of the Invention

[0005] To solve the above technical problems, the present invention proposes an on-line monitoring system and method for filling roof contact based on laser ranging to solve the problems existing in the above prior art.

[0006] To achieve the above object, the present invention provides an on-line monitoring system for filling roof contact based on laser ranging, including: laser ranging, a filling device and a monitoring and control module;

[0007] Wherein, the laser ranging is used to scan and obtain the height of the roof and floor and the roof shape data of the mined-out area by carrying an airborne laser scanning system and a laser ranging system;

[0008] The monitoring and control module is used to dynamically generate a filling rate-roof gap relationship curve based on the roof and floor heights and roof morphology data of the goaf;

[0009] The filling device is used to perform intelligent filling based on the filling rate-roof gap relationship curve.

[0010] Optionally, the monitoring and control module includes: a signal acquisition unit, a data processing and analysis unit, and an intelligent control and dynamic adjustment unit;

[0011] Among them, the signal acquisition unit is used to obtain the goaf morphology signal in real time based on the airborne laser scanning system;

[0012] The data processing and analysis unit is used to process the goaf morphology signal based on a multi-source fusion algorithm to obtain a filling rate-roof gap relationship curve;

[0013] The intelligent control and dynamic adjustment unit is used to adjust the grouting flow parameters based on the filling rate-roof gap relationship curve and a preset threshold, synchronously trigger an audible and visual alarm, and generate a disposal work order to guide the operator to perform precise supplementary injection.

[0014] The present invention also provides an online monitoring method for filling roof contact based on laser ranging for implementing the above system. The method includes:

[0015] Generating a three-dimensional point cloud model of the roof based on the roof and floor heights and roof morphology data of the goaf;

[0016] Adjusting the arrangement position of the laser ranging device based on the three-dimensional point cloud model of the roof;

[0017] Installing the laser ranging device based on the arrangement position of the laser ranging device, starting the installed laser ranging device, and sampling and measuring the time-varying distance between the filling body and the roof at the same time interval;

[0018] Starting the filling device, and introducing an environmental parameter compensation term through a resistance type temperature and humidity sensor during the filling roof contact process to correct the time-varying distance to obtain a compensated time-varying distance;

[0019] Based on the compensated time-varying distance, the monitoring and control module dynamically generates a filling rate-roof gap relationship curve;

[0020] Dynamically adjusting the grouting flow parameters based on the dynamically generated filling rate-roof gap relationship curve to complete the filling.

[0021] Optionally, the expression for generating the three-dimensional point cloud model of the roof is:

[0022]

[0023] In the formula, S is the distance measurement value obtained by the 3D laser scanner through the pulse ranging method, α is the lateral scanning angle, θ is the longitudinal scanning angle, c is the propagation speed of the laser in the atmosphere, and (X, Y, Z) are the 3D coordinates.

[0024] Optionally, the expression for calculating the compensated time-varying distance by introducing the environmental parameter compensation term is:

[0025]

[0026] In the formula, β and γ are the compensation coefficients for temperature T and humidity H, T0 and H0 are the reference temperature and humidity under the calibration environment, and ΔZ new represents the compensated time-varying distance, h represents the height difference between component A of the fixed laser ranging device and the bottom plate, and L AB represents the distance of the laser beam emitted from point A to point B, and L AB′ represents the distance of the laser beam emitted from point A to point B'.

[0027] Optionally, after the filling is completed, the laser ranging device is restarted for secondary ranging;

[0028] When the result of the secondary ranging shows that the filling body has undergone secondary settlement, the compensated time-varying distance is secondarily corrected based on the non-linear compression characteristics of the filling body material to obtain the time-varying distance considering secondary settlement;

[0029] Based on the time-varying distance considering secondary settlement, the intelligent control and dynamic adjustment unit issues a settlement warning to complete the final roof contact.

[0030] Optionally, the expression for calculating the time-varying distance considering secondary settlement is:

[0031]

[0032] In the formula, ΔZ comp represents the time-varying distance considering secondary settlement, λ is the material compression coefficient, and t is the filling time.

[0033] Compared with the prior art, the present invention has the following advantages and technical effects:

[0034] Based on high-density point cloud modeling, the airborne laser scanning system can accurately identify complex structural features such as roof overhangs and honeycomb fractures. By dynamically adjusting the elevation angle and rotation angle of the ranging device, the uniformity control of roof contact is achieved in the concave and convex surface areas, completely solving the filling blind area problem of traditional processes in the special-shaped roof scenario. Brief Description of the Drawings

[0035] The accompanying drawings, which form a part of this application, are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the accompanying drawings:

[0036] Figure 1 is a schematic diagram of three-dimensional scanning of a goaf in an embodiment of the present invention;

[0037] Figure 2 is a layout plan of laser rangefinders in an embodiment of the present invention;

[0038] Figure 3 is a schematic diagram of the working principle of a laser rangefinder during the process of the filling body contacting the roof in an embodiment of the present invention;

[0039] Figure 4 is a system diagram of an on-line laser ranging monitoring system in an embodiment of the present invention;

[0040] Figure 5 is a schematic diagram of the principle of triangulation ranging and linear ranging of a laser rangefinder in an embodiment of the present invention;

[0041] Figure 6 is a schematic diagram of three-dimensional inspection of the empty roof after the filling body is solidified in an embodiment of the present invention;

[0042] Figure 7 is a sectional view of a cuboid accommodation hole in an embodiment of the present invention;

[0043] Marking description: 1. UAV; 2. Three-dimensional laser scanner; 3. Target; 4. Roof; 5. Goaf; 6. Empty height; 7. Conducting wire; 8. Filling body; 9. Laser ranging device; 10. Cuboid accommodation hole; 11. Emitter lens; 12. Receiver lens; 13. Semiconductor laser; 14. Photosensitive element; 15. Ore pillar; 16. Filling retaining wall; 17. Filling slurry; 18. Filling pipeline; 19. Deterministic time-varying distance at time T; 20. Degenerate time-varying distance at time T+1; 21. Laser ranging; 211. Airborne laser scanning system; 212. Laser ranging system; 22. Filling device; 23. Monitoring and control module; 231. Signal acquisition unit; 232. Data processing and analysis unit; 233. Intelligent control and dynamic adjustment unit; 24. Borehole three-dimensional laser scanner; 25. Empty area; 26. Resistive temperature and humidity sensor; 27. Steel skeleton. Detailed implementation manners

[0044] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the accompanying drawings and combine with the embodiments to detail this application.

[0045] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0046] Embodiment 1

[0047] As Figure 1 shown, in this embodiment, an on-line monitoring system and method for filling roof contact based on laser ranging are provided. The core of the present invention is to pre-acquire the three-dimensional space parameters of the goaf through an airborne laser scanning system, including key data such as volume calculation, elevation reference plane, top and bottom plate elevations, and roof geometry. Based on the three-dimensional digital model generated by scanning, the layout points and spacing of the laser ranging devices can be scientifically planned to achieve millimeter-level dynamic monitoring of the lifting process of the filling body. The system restores the real geological structure through three-dimensional modeling technology, combines high-precision laser ranging with an automated control system to form a closed-loop management of the entire filling roof contact process, not only increasing the roof contact qualification rate to over 95%, but also effectively avoiding the safety risks of manual operation. Especially for goafs with complex and uneven roof shapes, this solution demonstrates significant technical adaptability and engineering practical value.

[0048] As a specific implementation manner of this embodiment, the on-line monitoring system for filling roof contact based on laser ranging includes: an airborne laser scanning system 211, a laser ranging system 212, a filling device 22, and a monitoring and control module 23; before the filling process starts, the airborne laser scanning system 211 is used to scan the goaf 5, and the obtained three-dimensional model data can be used to extract results such as the volume of the goaf, elevation plan, top and bottom plate heights, and roof shape; the laser ranging device 9 is arranged according to the top and bottom plate heights and roof shape of the scanned goaf 5 to monitor the time-varying distance from the filling body 8 in the goaf 5 to the roof; the monitoring and control module 23 includes a signal acquisition unit 231, a data processing and analysis unit 232, and an intelligent control and dynamic adjustment unit 233, which is used to analyze the ranging data. The on-line monitoring system for filling roof contact based on laser ranging provided by the present invention monitors the height of the filling body in real time through the laser ranging device 9 and adjusts the filling speed and flow rate at any time to prevent overfilling or underfilling.

[0049] An airborne laser scanning system 211 is used to scan the roof and floor heights and roof morphology of the goaf 5. The airborne laser scanning system 211 consists of a drone 1 and a 3D laser scanner 2, etc.; the 3D laser scanner 2 adopts SLAM (Simultaneous Localization and Mapping) technology and constructs a three-dimensional point cloud map of the goaf in real time through a 360° rotating 3D laser LiDAR sensor, realizing precise positioning (positioning accuracy ±0.1%) in an environment without GNSS, and can be mounted on a load-bearing drone 1 as a set of three-dimensional measurement systems; in addition, in view of problems such as the spatial limitation of the flight of the drone caused by the ore pillar 15 in the goaf 5 as a temporary support structure, the airborne laser scanning system 211 integrates a spherical obstacle avoidance algorithm, supports 360° omnidirectional obstacle detection (obstacle avoidance distance <1m), ensures the safe flight of the drone in narrow roadways (width ≥1.5m) and complex roof structures, and can realize automatic point cloud stitching and on-site instant data processing. Finally, the maximum ranging of the airborne laser scanning system 211 is 100m, the laser accuracy is + / -3cm, the measurement range is 360°×360°, the acquisition frequency is 300,000pt / s, and the flight speed is 5m / s and above.

[0050] Furthermore, as Figure 1 shown, select the entrance of the goaf 5 as the starting measurement site or the initial target 3, and use the airborne laser scanning system 211 to be stationary at this point for 10s. Use the drone 1 to mount the 3D laser scanner 2 to conduct a 360° detailed scan of the goaf 5 at a flight speed of 5m / s and an acquisition frequency of 300000pt / s. The 3D laser scanner 2 is a Hovermap system.

[0051] The core optical components of the laser ranging device 9 include a transmitter lens 11 and a receiver lens 12, which are respectively used for collimating the emitted laser beam and focusing the reflected signal. The semiconductor laser 13 serves as the light source module and can emit near-infrared pulsed laser with a wavelength of 905 nm, and its peak power reaches 50 W. It cooperates with the photosensitive element 14 (using an avalanche photodiode APD) to achieve high-sensitivity reception of weak reflected light. The laser ranging device 9 excavates a cuboid accommodation hole 10 with a size of 210×90×260 mm (length×width×height) at a predetermined position according to the top and bottom plate height and shape data of the mined-out area 5 obtained by the airborne laser scanning system 211. When installing the device, first weld the prefabricated steel skeleton 27 support structure in the hole, and then fix the laser rangefinder main body on the steel skeleton 27 through a universal rotating component to ensure that its 360° omnidirectional rotation is not restricted. A resistive temperature and humidity sensor 26 is installed on the steel skeleton 27 50 cm directly below the rangefinder. The outside of the sensor is wrapped with a silica gel seal and a stainless steel protective net, and the protection level reaches IP68, which can resist the splashing of filling slurry and the impact of rock debris. All wires 7 (including laser signal wires, sensor data wires, and power supply lines) are sleeved with armored bellows, routed along the inside of the steel skeleton 27 and fixed with buckles to avoid mechanical damage. The core unit of this device includes a laser transmitter, a receiver, a high-precision timing module, and a temperature and humidity compensation circuit. The measurement range covers 0.05 - 200 m, and the basic accuracy is ±1.5 mm. By real-time collecting the ambient temperature and humidity data, the refractive index deviation of the laser in the atmosphere is automatically corrected, so that the measurement stability of ±2 mm is still maintained under extreme working conditions (temperature of 0 - 40 °C, humidity of 95%). The rotating base adopts a ceramic bearing and waterproof grease seal design, combined with an explosion-proof cast aluminum shell, to ensure continuous operation for 2000 hours without failure in an environment with a dust concentration of 200 mg / m 3 environment.

[0052] The monitoring and control module 23 is composed of three functional units: signal acquisition, data processing and analysis, and intelligent dynamic regulation. The front-end acquisition unit built in the airborne laser scanning system 211 can obtain the elevation of the top and bottom plates of the goaf 5 and the three-dimensional topography data of the roof in real time, providing an accurate spatial coordinate reference for the layout of the laser ranging device 9. The laser ranging terminal realizes data interconnection with the signal acquisition unit 231 through shielded twisted pair wires, and captures the millimeter-level dynamic displacement during the filling body lifting process at a sampling frequency of 50 Hz. The data processing and analysis unit 232 integrates a multi-source data fusion algorithm, registers the laser ranging value, temperature and humidity compensation parameters with the three-dimensional point cloud model in space, generates a filling rate-roof gap relationship curve in real time, and conveys regulation instructions to the filling station through a 4-20 mA industrial bus. The intelligent control and dynamic adjustment unit 233 is equipped with a two-level early warning mechanism: when the roof contact gap in a local area exceeds 3 mm, the system automatically reduces the grouting flow rate in this area and triggers a buzzer alarm; if deviations of more than 5 mm continuously occur at multiple points, an emergency shutdown protocol is started. All abnormal data is synchronously uploaded to the mine digital twin platform to form a filling quality heat map with spatial coordinate marks, providing visual navigation for subsequent supplementary grouting operations.

[0053] As another specific implementation manner of this embodiment, this embodiment provides an on-line monitoring method for filling roof contact based on laser ranging, which specifically includes the following steps:

[0054] Generate a three-dimensional point cloud model of the roof based on the height of the top and bottom plates of the goaf and the roof shape data;

[0055] Adjust the layout position of the laser ranging device 9 based on the three-dimensional point cloud model of the roof;

[0056] Install the laser ranging device based on the layout position of the laser ranging device 9, start the installed laser ranging device 9, and sample and measure the time-varying distance between the filling body and the roof at the same time interval;

[0057] Start the filling device 22, and introduce an environmental parameter compensation term through the set resistive temperature and humidity sensor 26 during the filling roof contact process to correct the time-varying distance to obtain the compensated time-varying distance;

[0058] Based on the compensated time-varying distance, the monitoring and control module 23 dynamically generates a filling rate-roof gap relationship curve;

[0059] Dynamically adjust the grouting flow rate parameters based on the dynamically generated filling rate-roof gap relationship curve to complete the filling.

[0060] In order to accurately grasp the three-dimensional spatial form of goaf 5, the entrance of goaf 5 is selected as the starting point or initial target, and the airborne laser scanning system 211 is used to stay still at this point for 10 seconds. Further, the goaf 5 is scanned in detail at a flight speed of 5m / s, and the information such as the top and bottom plate height and the top plate form are extracted through the built-in signal acquisition unit 231 and the data processing and analysis unit 232. Among them, a conventional goaf three-dimensional modeling method dynamically obtains the pitch angle θ, azimuth angle α and pulse ranging value S of the goaf top plate through the three-dimensional laser scanner carried by the drone, and generates a three-dimensional point cloud model of the top plate in real time according to the following formula, and uses this as a proactive condition to dynamically adjust the layout of the laser ranging device.

[0061]

[0062] Where: S is the distance measurement value obtained by the three-dimensional laser scanner through the pulse ranging method, α is the horizontal scanning angle, θ is the vertical scanning angle, c is the propagation speed of the laser in the atmosphere, and t is the round-trip propagation time of the laser at the distance to be measured.

[0063] After the airborne laser scanning system 211 is finished working, a filling retaining wall 16 is built in the mining field. It is set at the entrance of the goaf, and the filling pipe 18 and the monitoring cable channel are pre-buried inside, which can effectively isolate the filling slurry 17 and guide it to flow into the goaf. When formulating the layout plan of the filling pipe 18, it should be kept at a distance of 1 to 2 meters from the laser ranging device 9 to avoid interference with the laser ranging device 9 caused by factors such as the filling slurry 17, temperature, and humidity.

[0064] Before the filling process begins, the arrangement position of the laser distance measuring device 9 is roughly determined based on the information such as the top and bottom plate height 6 and the top plate 4 shape obtained by the airborne laser scanning system 211.

[0065] in accordance with Adjust the spacing L of each laser distance measuring device 9, b is the total length of the goaf, a is taken as 0, and m is the number of spacing L.

[0066] Considering that the laser distance measuring device 9 is not taken out after use, too many spacings m will increase the cost of the laser distance measuring device 9, and too few spacings will affect the filling and top connection rate. Therefore, consider m≈1.87*(n-1) 0.4 The number of intervals is determined, where n is the number of laser distance measuring devices 9 .

[0067] like Figure 2 As shown, based on the three-dimensional shape data of the top and bottom plates of the goaf 5 obtained by the airborne laser scanning system 211, H is determined according to the spacing L along the top plate 4. f1 , H f2 , …, H fnIt is the final ranging point, and standard cuboid accommodation holes 10 with dimensions of 210×90×260mm (length×width×height) need to be excavated at each point. During construction, double constraints need to be met: firstly, ensure that the laser transmission path between the roof 4 and the filling body 8 is unobstructed; secondly, ensure that the laser ranging device 9 is completely embedded in the roof structure to prevent outward protrusion from affecting the quality of filling contact with the roof.

[0068] During installation, first weld a prefabricated steel skeleton 27 in the cuboid accommodation hole 10 as a support system, and fix the main body of the laser ranging device 9 to the steel skeleton 27 through a universal rotating component to achieve 360° omnidirectional non-blind-spot ranging. Install a resistive temperature and humidity sensor 26 on the steel skeleton 27 500mm directly below the laser ranging device 9. Its outer layer is encapsulated with a composite of a silica gel sealing sleeve and a stainless steel protective net, reaching the IP68 protection level, which can effectively resist slurry splashing and rock debris impact.

[0069] All wires 7 (including laser signal wires, sensor data lines, and power supply lines) are protected by armored bellows and are fixed along the inner side of the steel skeleton 27 through preset wire groove buckles to form a three-dimensional wiring system resistant to mechanical damage.

[0070] By real-time collecting the environmental parameters of the resistive temperature and humidity sensor 26, dynamically correct the deviation of the atmospheric refractive index, and still maintain a measurement stability of ±2mm under extreme conditions of 0 - 40°C temperature and 95% humidity.

[0071] The rotating base of the laser ranging device 9 adopts a composite sealing technology of ceramic bearings and waterproof grease, combined with an explosion-proof cast aluminum shell, to ensure 2000 - hour maintenance-free operation under the working condition of a dust concentration of 200mg / m 3 under the working condition of a dust concentration of 200mg / m³.

[0072] Figure 7 Further refine the installation standard, requiring the use of anti-loosening bolts to anchor the connecting components to the preset base of the accommodation hole, and achieve equipotential connection between the device and the power distribution system through shielded wires laid along the roadway roof.

[0073] When the filling work starts, start the laser ranging device 9, sample at the same time interval, the laser ranging device 9 continuously measures the time-varying distance ΔZ between the filling body and the roof, and the monitoring system compares the ranging points H f1 ,H f2 ,…,H fn with the height of the filling body in real time, and adjust the filling speed and flow rate at any time to prevent overfilling or underfilling.

[0074] According to the linear measurement principle, the formula for the time-varying distance ΔZ is as follows:

[0075]

[0076] In the formula, d fnis the time-varying distance, t is the time required for the light wave to travel to and fro, and c atm is the actual propagation speed of the corrected light speed:

[0077]

[0078] In the formula, c0 is the propagation speed of the laser in the atmosphere, n(T, P, H) is the atmospheric refractive index, which is related to the temperature T (K), air pressure P (hPa), and humidity H (%).

[0079] Considering the situation of under-connection at the edge during the filling and roof-supporting process, the laser ranging device 9 is arranged as Figure 5 shown. The connecting component of the laser ranging device 9 is fixed to A through bolts. The height difference h between A and the bottom plate is measured by the linear measurement principle. Since the height of the filling body is constantly changing, the inclination angle θ of the laser ranging device 9 is also constantly changing, and the laser beam emitted from point A to point B changes to B′ accordingly. The distances from A to B and B′ are L AB , L AB′ . In addition, in order to solve the influence of temperature and humidity on the laser propagation speed and improve the measurement stability in the complex mine environment, resistive temperature and humidity sensors 26 are arranged in the stope, aiming to dynamically adjust the ranging value through the environmental parameter compensation term and reduce the error caused by environmental interference.

[0080] Based on the triangulation principle and the compensated time-varying distance ΔZ introduced with the environmental parameter compensation term new The calculation formula is as follows:

[0081]

[0082] In the formula, β and γ are the compensation coefficients for temperature T and humidity H, which are calibrated through experiments; T0 and H0 are the reference temperature and humidity under the calibration environment.

[0083] In order to solve the problem of roof-supporting failure caused by the secondary settlement of the filling body after solidification, the non-linear compression characteristics of the filling body material are considered. At this time, the time-varying distance ΔZ considering the secondary settlement comp The calculation formula is updated to:

[0084]

[0085] In the formula, λ is the material compression coefficient, which is calibrated through laboratory tests; t is the filling time.

[0086] As Figure 4As shown in the figure, the monitoring and control module 23 adopts a three-level joint control architecture: The signal acquisition unit 231 obtains the morphological signals of the goaf 5 in real time through the airborne laser scanning system, and captures the millimeter-level displacement signals of the laser ranging terminal at a sampling frequency of 50 Hz; The data processing and analysis unit 232 uses a multi-source fusion algorithm to perform spatial registration on the ranging values, temperature and humidity parameters, and point cloud model, and dynamically generates a filling rate-roof clearance relationship curve; When it is detected that the roof contact clearance in a local area exceeds the design threshold, the intelligent control and dynamic adjustment unit 233 immediately adjusts the grouting flow parameters through a 4-20 mA industrial bus, synchronously triggers an audible and visual alarm, and generates a handling work order to guide the operators to implement precise supplementary injection. All abnormal data are mapped to the mine digital twin platform in real time, and a filling quality heat map is output to provide three-dimensional visual navigation for subsequent roof contact acceptance. This interlock control system strictly ensures the contact density between the filling body 8 and the roof 4. When unacceptable deviations continuously occur at multiple points, the system automatically executes an emergency shutdown protocol.

[0087] At the end of filling, the height of the filling body is at the deterministic time-varying distance 19 at time T as shown in the figure. Figure 3 shown.

[0088] After the filling is solidified, the laser ranging device 9 is started again for precise ranging to confirm the final roof contact effect of the filling body 8, and to monitor whether there is secondary settlement of the filling body 8, that is, the change from the deterministic time-varying distance 19 at time T to the degenerate time-varying distance 20 at time T+1. If settlement problems are found, the intelligent control and dynamic adjustment unit 233 will issue a warning to remind the staff to take further supplementary work to ensure that the final filling roof contact effect meets the design standards. In addition, as shown in the figure, boreholes can be drilled in the overlying strata or roof, and the borehole three-dimensional laser scanner 24 (C-ALS, endoscope type) can enter the goaf 25 from the hole, and the final roof contact effect can be confirmed through three-dimensional scanning. Figure 6 shown.

[0089] Compared with traditional technologies, this solution has three core advantages:

[0090] (1) Relying on the laser ranging accuracy of ±1.5 mm, it realizes the millimeter-level capture of the lifting trajectory of the filling body, and improves the roof contact qualification rate from the industry average of 70% to over 95%;

[0091] (2) By constructing a "perception - analysis - execution" closed loop through the intelligent control system, the filling station can automatically adjust the grouting pressure and flow according to the real-time three-dimensional clearance heat map, reducing the single-shift manual inspection frequency by 80%, and avoiding the potential hidden dangers of personnel entering high-risk working faces;

[0092] (3) Based on high-density point cloud modeling, the airborne laser scanning system can accurately identify complex structural features such as roof hanging bodies and honeycomb fissures. By dynamically adjusting the elevation angle and rotation angle of the ranging device, the uniformity control of roof contact is achieved in concave and convex areas, completely solving the filling blind area problem of traditional processes in the scenario of special-shaped roofs.

[0093] In this embodiment, by using laser ranging technology to perform real-time ranging on the filling body, the ranging accuracy is high and continuous, and it can achieve efficient and safe filling roof contact monitoring under complex roof structures, greatly improving the mine production efficiency and safety guarantee level.

[0094] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An on-line monitoring system for filling roof contact based on laser ranging, characterized in that, Including: Laser ranging (21), filling device (22) and monitoring and control module (23); Among them, the laser ranging (21) is used to carry an airborne laser scanning system (211) and a laser ranging system (212) to scan and obtain the top and bottom plate heights and roof morphology data of the goaf; The monitoring and control module (23) is used to dynamically generate a filling rate-roof gap relationship curve based on the top and bottom plate heights and roof morphology data of the goaf; The filling device (22) is used to perform intelligent filling based on the filling rate-roof gap relationship curve.

2. The online monitoring system for filling and roof contact based on laser ranging according to claim 1, characterized in that, The monitoring and control module (23) includes: a signal acquisition unit (231), a data processing and analysis unit (232), and an intelligent control and dynamic adjustment unit (233); Among them, the signal acquisition unit (231) is used to obtain the goaf morphology signal in real time based on the airborne laser scanning system (211); The data processing and analysis unit (232) is used to process the goaf morphology signal based on a multi-source fusion algorithm to obtain a filling rate-roof gap relationship curve; The intelligent control and dynamic adjustment unit (233) is used to adjust the grouting flow rate parameter based on the filling rate-roof gap relationship curve and a preset threshold, synchronously trigger an audible and visual alarm, and generate a disposal work order to guide the operator to perform precise supplementary injection.

3. An on-line monitoring method for backfill roof contact based on laser ranging, characterized in that, For implementing the system as described in claims 1-2, the method includes: Generating a three-dimensional point cloud model of the roof based on the top and bottom plate heights and roof morphology data of the goaf; Adjusting the layout position of the laser ranging device (9) based on the three-dimensional point cloud model of the roof; Installing the laser ranging device based on the layout position of the laser ranging device (9), starting the installed laser ranging device (9), and performing sampling measurements of the time-varying distance between the filling body and the roof at the same time interval; Starting the filling device (22), and introducing an environmental parameter compensation term during the filling contacting the roof process to correct the time-varying distance to obtain a compensated time-varying distance; Based on the compensated time-varying distance, the monitoring and control module (23) dynamically generates a filling rate-roof gap relationship curve; Dynamically adjusting the grouting flow rate parameter based on the dynamically generated filling rate-roof gap relationship curve to complete the filling.

4. The online monitoring method for filling and roof contact based on laser ranging according to claim 3, characterized in that, The expression for generating a three-dimensional point cloud model of the roof is: In the formula, S is the distance measurement value obtained by the three-dimensional laser scanner through pulse ranging, α is the lateral scanning angle, θ is the longitudinal scanning angle, c is the propagation speed of the laser in the atmosphere, and (X, Y, Z) are the three-dimensional coordinates.

5. The online monitoring method for filling and roof contact based on laser ranging according to claim 4, characterized in that The expression for introducing an environmental parameter compensation term to calculate the compensated time-varying distance is: In the formula, β and γ are compensation coefficients of temperature T and humidity H, T0 and H0 are the reference temperature and humidity under the calibration environment, and ΔZ new represents the compensated time-varying distance, h represents the height difference between component A of the fixed laser ranging device (9) and the bottom plate, and L AB represents the distance of the laser beam emitted from point A to point B, and L AB′ represents the distance of the laser beam emitted from point A to point B'.

6. According to the online monitoring method for filling contacting the roof based on laser ranging as described in claim 5, characterized in that After the filling is completed, start the laser ranging device (9) again for secondary ranging; When the result of the secondary ranging is that the filling body undergoes secondary settlement, the compensated time-varying distance is secondarily corrected based on the non-linear compression characteristics of the filling body material to obtain a time-varying distance considering secondary settlement; Based on the time-varying distance considering secondary settlement, the intelligent control and dynamic adjustment unit (233) issues a settlement warning to complete the final roof contact.

7. The online monitoring method for filling and roof contact based on laser ranging according to claim 6, characterized in that The expression for calculating the time-varying distance considering secondary settlement is: where ΔZ comp represents the time-varying distance considering secondary settlement, λ is the material compression coefficient, and t is the filling time.

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