A method for precast coal filling mining

Abstract

The application discloses a kind of prefabricated coal filling mining methods.The method comprises the following steps: S1, after completing a coal mining operation at fully mechanized working face, control the filling hydraulic support to move forward in sequence, drive the single-track crane track to extend forward synchronously;S2, by prefabricated coal transport storage train continuously transports prefabricated coal body to working face, uses prefabricated coal transport installation robot to transport prefabricated coal body to the specified filling position in goaf;S3, at the specified filling position, control prefabricated coal transport installation robot to stack, align and assemble multiple prefabricated coal bodies in vertical direction layer by layer, form prefabricated coal support column stably supported between goaf roof and floor;S4, repeat steps S1 to S3 until the mining and filling of the whole working face are completed.The application realizes unmanned, high efficiency, low cost and reusability of goaf resources of filling mining through prefabricated coal column robotized automatic assembly and mining and filling synchronous process.

Description

Technical Field

[0001] This invention relates to the field of intelligent coal mining technology, and in particular to a precast pier coal backfilling mining method. Background Technology

[0002] With the increasing depletion of shallow coal resources, deep and complex geological mining has become the norm, leading to increasingly prominent safety issues such as goaf subsidence, ecological damage, gas accumulation, and rock bursts. Backfilling mining technology, as an effective way to control surrounding rock deformation, reduce surface subsidence, improve resource recovery rates, and achieve green mining, has become an important development direction for safe and efficient coal mining.

[0003] The backfilling mining methods in related technologies mainly include gangue backfilling, paste backfilling, and high-water-content material backfilling. While these methods alleviate safety issues caused by goaf areas to some extent, the backfilling process often involves transporting backfill materials to the goaf via pipelines or vehicles, followed by spreading and compaction. This process is limited by material preparation, transportation capacity, and underground space constraints. Backfilling operations often lag behind the coal mining advance speed, severely restricting the mining efficiency of the working face and making it difficult to achieve parallel mining and backfilling operations.

[0004] The filling area is usually located behind the goaf, in a complex environment with potential safety hazards such as roof collapse and accumulation of harmful gases. A large amount of material handling, equipment operation, and quality control still require manual intervention, which is not only labor-intensive but also exposes workers to a high-risk environment for extended periods, making it difficult to guarantee their personal safety.

[0005] The filling method requires the establishment of surface filling stations, the laying of complex transportation pipelines, or reliance on a large number of mine cars for transportation, resulting in large system investment and high maintenance costs. In addition, the preparation, transportation, and solidification processes of filling materials require strict control, leading to high overall operating costs and poor economic benefits, which limits the large-scale application of this technology in medium and large-sized mines.

[0006] The filling technology has limited adaptability to geological conditions of the working face (such as dip angle, faults, and roof and floor stability) and mining processes (such as retreat mining). In particular, retreat mining requires the excavation of a large number of roadways in advance, resulting in a long preparation period, high costs, and difficulties in roadway maintenance, which further increases the complexity and cost of the technology implementation.

[0007] Once the filling material is formed, its shape is fixed, and it is difficult to form a regular space that can be used inside. This limits the secondary development and utilization of resources in the goaf and fails to fully realize the potential value of filling mining. Summary of the Invention

[0008] The present invention aims to at least partially solve one of the technical problems in the related art.

[0009] Therefore, embodiments of the present invention propose a precast pier coal backfilling mining method, which achieves unmanned, high-efficiency, low-cost backfilling mining and the reuse of goaf resources through robotic automatic assembly of precast piers and synchronous mining and backfilling processes.

[0010] The precast pier coal backfilling mining method of this invention includes:

[0011] S1. After the coal mining machine completes a coal mining operation in the fully mechanized mining face, the filling hydraulic support behind the coal mining machine is controlled to move forward in sequence to support the newly exposed roof. During the forward movement of the filling hydraulic support, the monorail at the tail of the filling hydraulic support is driven to extend forward synchronously, forming a dynamically moving material transport channel in the goaf area behind the fully mechanized mining face. S2, standardized precast piers are continuously transported to the working face by a precast pier transport and storage train arranged along the roadway, and the precast pier transport and installation robot running on the monorail is used to grab the precast piers from the transport and storage train and transport them to the designated filling position in the goaf. S3, at the designated filling location, control the precast pier transportation and installation robot to stack, align and assemble multiple precast piers layer by layer in the vertical direction to form a precast pier support column that provides stable support between the top and bottom plates of the goaf. S4. Repeat steps S1 to S3 to make the advancement of the fully mechanized mining face and the construction of the precast pier support columns proceed synchronously and cyclically until the mining and filling of the entire working face is completed.

[0012] In some embodiments, in step S1, the monorail is fixed to the tail beam or base of the filling hydraulic support in a detachable or hinged manner via a connector, so that it moves as a whole as the support pulls.

[0013] In some embodiments, in step S2, multiple precast pier transport and installation robots are set up to work collaboratively on the monorail track. The task allocation of each precast pier transport and installation robot is dynamically scheduled by the central controller based on the position of the transport and storage train, the progress of each filling position, and the real-time status of the robot.

[0014] In some embodiments, the precast pier transport and installation robot includes a walking mechanism, a robotic arm, and an end effector. The walking mechanism is matched with the monorail track, the robotic arm is used for multi-degree-of-freedom movement, and the end effector is a clamp with gripping, adsorption, or pin docking functions, used to grasp and transport the precast piers and complete inter-layer alignment and connection.

[0015] In some embodiments, in step S3, the precast pier is a modular structure with a standardized design, and its upper and lower surfaces are provided with interlocking mechanisms. When the precast pier is assembled, the interlocking mechanisms of the upper and lower precast piers are aligned and connected by the control of the precast pier transport and installation robot to form the precast pier support column that bears the overall force.

[0016] In some embodiments, the interlocking mechanism is a tenon and groove mating structure, a male and female connector pin structure, or a snap-fit ​​structure with a positioning guide surface. The end effector of the precast pier transport and installation robot has a built-in force sensor and a vision positioning system for real-time feedback of alignment accuracy and connection status during assembly.

[0017] In some embodiments, in step S3, the constructed precast pier support columns are arranged in a matrix or quincunx pattern within the goaf, with regular gaps between each precast pier support column.

[0018] In some embodiments, after the mining and backfilling operations are completed, the gap space between the precast pier support columns is sealed and reinforced to transform it into an underground storage facility for sealing carbon dioxide, storing compressed air, or other materials.

[0019] In some embodiments, the top or tail beam of the filling hydraulic support is integrated with an environmental monitoring sensor for real-time monitoring of the roof pressure, delamination information and gas concentration in the goaf behind it, and the monitoring data is fed back to the central controller for dynamic adjustment of the arrangement density and assembly speed of the precast pier support columns or triggering an early warning.

[0020] The precast pier coal backfilling mining method of this invention, by employing forward mining combined with a dynamic monorail transport channel, achieves completely synchronous parallel operations of coal mining and backfilling, solving the problems of large-scale roadway engineering and mutual interference between mining and backfilling in traditional processes, and improving mining efficiency. A track-mounted robot automatically grasps and transports standardized precast piers, and precisely assembles them into structured support columns within the goaf, thereby replacing manual operation in high-risk environments and achieving safe, unmanned backfilling.

[0021] The resulting regular column arrangement not only effectively controls the roof and ensures safety, but the regular gaps between the columns also provide conditions for subsequent conversion into underground space utilization such as carbon dioxide storage facilities or compressed air energy storage. The entire system only requires moderate modifications to the existing fully mechanized mining equipment, and through integrated environmental monitoring and central intelligent scheduling, the system possesses adaptive optimization capabilities. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the underground layout of the equipment supporting the precast pier coal backfilling mining method according to an embodiment of the present invention.

[0023] Figure 2 This is a partial schematic diagram of the stacking process of precast piers at the filling position according to an embodiment of the present invention.

[0024] Figure 3 This is a partial schematic diagram of the transport and storage train arranged underground according to an embodiment of the present invention.

[0025] Figure label: 1-Coal mining machine; 2-Hydraulic support for filling; 3-Monorail track; 4-Transport and storage train; 5-Precast piers; 6-Robot; 7-Support column; 8-Connecting parts. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The precast pier coal backfilling mining method of the present invention is described below with reference to the accompanying drawings.

[0028] like Figures 1 to 3 As shown, the precast pier coal backfilling mining method of this invention includes: S1, after the coal mining machine 1 completes a coal mining operation in the fully mechanized mining face, the filling hydraulic support 2 behind the coal mining machine 1 is controlled to move forward in sequence to support the newly exposed roof. During the forward movement of the filling hydraulic support 2, the monorail hoisting track 3 located at the tail of the filling hydraulic support 2 is driven to extend forward synchronously, forming a dynamically moving material transport channel in the goaf area behind the fully mechanized mining face.

[0029] The monorail track 3 is connected to the tail of the hydraulic support 2 for filling, ensuring that the transport path is always anchored at the forefront of the supported area (tail of the support). The standard cyclical action of the coal mining machine 1 cutting coal and moving the support forward (pulling the support) not only completes mining and support but also simultaneously and automatically extends the transport channel in the filling area. This step is crucial for achieving forward mining and filling, eliminating the need for pre-excavation and maintenance of numerous dedicated filling roadways required by traditional backward mining. The transport channel is constructed as mining progresses, without the need for advance excavation.

[0030] The extension of the transportation channel is completely synchronized with the coal mining progress, achieving zero-delay connection between coal mining and backfilling preparation in time and space. This lays the physical foundation for subsequent high-efficiency backfilling operations, avoids the need for separate tunnels to be excavated for backfilling, and reduces the amount of work and construction costs. The backfilling operation area (monorail crane operating area) is always adjacent to the roof fully supported by hydraulic supports, and the safety of the working environment is far superior to that of traditional backfilling operation points deep in mined-out areas.

[0031] S2, standardized precast piers 5 are continuously transported to the working face by the precast pier transport and storage train 4 arranged along the roadway. The precast pier transport and installation robot 6, which runs on the monorail track 3, grabs the precast piers 5 from the transport and storage train 4 and transports them to the designated filling position in the goaf.

[0032] Precast piers 5 are used as filling units, pre-produced in factories or on the ground, ensuring controllable quality and uniform specifications, replacing the complex process of traditional on-site mixing and pumping of irregularly shaped filling materials underground. The precast pier transport and storage train 4 serves as a mobile warehouse, providing continuous material supply. The precast pier transport and installation robot 6 runs on a dynamic monorail track 3, achieving precise three-dimensional spatial delivery from the warehouse to designated coordinates, forming a flexible logistics system consisting of a track network and the mobile robot 6.

[0033] From material handling to transportation, the entire process is executed by Robot 6, completely freeing workers from heavy and dangerous material handling positions, thus responding to the core objective of reducing hazardous work. Rail transport is smooth and efficient, unaffected by floor conditions; Robot 6 handles materials accurately and quickly. Compared to mine car transfers or pipeline pumping, this system is more reliable, easier to automate, and allows for better matching of transport capacity with mining progress. It eliminates the need for complex ground filling stations, high-pressure pumping pipelines, and related cleaning and maintenance work, greatly simplifying the entire filling system.

[0034] S3, at the designated filling location, the precast pier transport and installation robot 6 controls multiple precast piers 5 to be stacked, aligned and assembled layer by layer in the vertical direction to form a precast pier support column 7 that provides stable support between the top and bottom plates of the goaf.

[0035] Structured support replaces dense filling, transforming the concept of filling into structured support. Instead of filling the space with loose or flowing materials, robots 6 assemble modular units into support columns 7 that can actively bear the pressure of the roof slab. The support columns 7 form rigid or semi-rigid contact with the roof and floor slabs, providing timely support. By controlling the robotic arm and end effector of robot 6, millimeter-level alignment, placement, and connection of prefabricated piers 5 in three-dimensional space are achieved (e.g., through grooves, pins, etc.).

[0036] The Robot 6 assembly system achieves full automation of the filling operation. The precast columns immediately provide support after assembly, which can more effectively control the early delamination and subsidence of the goaf roof, superior to the passive support method of traditional filling materials that slowly solidify to reach strength. Only a portion of the goaf volume of material (i.e., the column part) is needed to support the roof, which significantly reduces the consumption and cost of filling materials compared to filling the entire space.

[0037] Furthermore, the columnar support naturally preserves regular and interconnected gaps between the columns, providing a structural basis for subsequent space utilization (such as CO2 sequestration), which is an added value that traditional dense filling cannot achieve.

[0038] S4. Repeat steps S1 to S3 to make the advancement of the fully mechanized mining face and the construction of the precast pier support pillars 7 proceed synchronously and cyclically until the mining and filling of the entire working face is completed.

[0039] This step defines S1-S3 as a complete, repeatable process cycle of coal mining, support shifting, transportation, and assembly. The entire system is operated with an integrated control system to coordinate the timing and spatial arrangement of the actions of multiple devices, including the coal mining machine 1, the filling hydraulic support 2, the monorail track 3, the robot 6, and the transport and storage train 4.

[0040] Since the backfilling operation is carried out simultaneously with the next cycle of coal mining in the goaf behind the support, it basically does not occupy the production time of the coal mining face, thus minimizing the impact on the efficiency of the original mining process.

[0041] In some embodiments, in step S1, the monorail track 3 is fixed to the tail beam or base of the filling hydraulic support 2 in a detachable or hinged manner via the connector 8, so that it moves as a whole with the movement of the support puller.

[0042] For example, the articulated connector 8 includes components such as pins, ear plates, and ball joints, which form a connection between the monorail track 3 and the filling hydraulic support 2 that can rotate around one or more axes. This can effectively compensate for the relative displacement and angle changes between the track and the support caused by unevenness of the base plate and adjustment of the support posture (such as lifting and swinging) during the advancement of the working face, and prevent stress concentration and damage caused by rigid connection.

[0043] Alternatively, the detachable connector 8 includes quick-release clips, pin-slot connections, bolted connections, etc., allowing the track to be separated from the support when needed. When a section or connection point of the monorail track 3 is damaged, it can be quickly disassembled and replaced without cutting or welding, greatly improving the maintainability and availability of the system.

[0044] Specifically, such as Figure 2 and Figure 3 As shown, in practical applications, a chain is used as the connector 8 to suspend the monorail track 3 on the tail beam of the filling hydraulic support 2. It consists of a high-strength round link chain, shackles, adjusting chain links (such as turnbuckles), and a dedicated track suspension beam or lugs. The upper end of the chain is connected to the suspension lugs fixed to the lower surface of the support tail beam via shackles, and the lower end is connected to the load-bearing beam of the monorail track 3 via shackles or directly. This utilizes the mechanical property of the chain, which only bears tensile force and almost no bending moment or compressive force.

[0045] The chain can swing freely in three-dimensional space, perfectly absorbing the relative displacement in all directions caused by the lifting, swaying and undulation of the support, and the undulation of the base plate. This ensures that the track moves smoothly and stably with the support without causing the system to stop due to jamming or deformation, and it is highly adaptable to complex geological conditions.

[0046] In some embodiments, in step S2, multiple precast pier transport and installation robots 6 are set up to work collaboratively on the monorail track 3. The task allocation of each precast pier transport and installation robot 6 is dynamically scheduled by the central controller based on the position of the transport and storage train 4, the progress of each filling position, and the real-time status of the robot 6.

[0047] The central controller collects and integrates three types of key information in real time through various sensors and communication networks deployed in the system, and constructs a digital twin potential map of the entire work site.

[0048] Material supply status: the location of transport and storage train 4, the type, quantity, and arrangement order of prefabricated piers 5 in each train compartment.

[0049] Task requirements status: progress of each filling location, including ready locations (support has been moved forward and space has been made available), locations under construction, and completed locations; the type and quantity of precast piers required for each filling location; and roof pressure monitoring data (which may affect the priority of support at that location).

[0050] Actuator resource status: The real-time status of Robot 6, including position, power / hydraulic pressure, current task, working status of the robotic arm and end effector (normal, fault, busy, idle), running speed, etc.

[0051] Based on the aforementioned real-time situation, the central controller runs its built-in scheduling algorithm. The core of its logical model is to solve the optimization problem of task allocation and path planning for multiple robots (6 tasks). The decision-making logic includes the following levels: Task decomposition and release: The macro-objective of filling the entire area behind the working face is decomposed into countless micro-atomic tasks, which involve transporting prefabricated piers 5 with specific numbers to filling positions at specific coordinates and completing specific actions (grabbing, transporting, placing, docking).

[0052] Robot 6 - Task Matching: The system assigns tasks to the required robots (6). Matching principles are typically based on multi-objective optimization. For example, minimizing the total completion time of all tasks is a primary objective. The algorithm considers the current position and speed of the robots (6), as well as the spatial distribution of task points, avoiding clustering or long-distance travel. If the pressure on a certain top plate suddenly increases (sensor alarm), the controller dynamically increases the priority of the filling task at that location and schedules the nearest or most suitable robot (6) to handle it first. This prevents one robot (6) from being overloaded while others remain idle. When an abnormal state of a robot (6) is detected (e.g., low battery, joint overheating), its task is dynamically transferred to another robot (6), and a charging or maintenance task is assigned to it.

[0053] The controller continuously monitors the task execution status, such as whether robot 6 arrives on time, whether the grasping is successful, and whether the assembly accuracy meets the standard (through feedback from the force / vision sensors at the end of robot 6).

[0054] When unexpected events occur (such as: transport and storage train 4 suspending resupply due to a malfunction, an abnormality in the base plate at a filling location requiring adjustment of the plan, or robot 6 experiencing a sudden malfunction), the controller can respond quickly. Based on the new situation, it instantly recalculates and distributes new task sequences to ensure that the system can still operate towards the optimal goal under disturbances.

[0055] In some embodiments, the precast pier transport and installation robot 6 includes a walking mechanism, a robotic arm, and an end effector. The walking mechanism is matched with the monorail track 3, the robotic arm is used for multi-degree-of-freedom motion, and the end effector is a clamp with gripping, adsorption, or pin docking functions, used to grasp and transport the precast pier 5 and complete the inter-layer alignment and connection.

[0056] The traveling mechanism is a suspended track-based mobile platform, adapted to the drive and suspension systems of underground I-beams or dedicated monorail tracks 3. The drive unit includes an explosion-proof motor, a reducer, and drive wheels. The drive wheels (usually rubber tires) press tightly against the upper surface or side of the lower flange of the monorail track 3, relying on friction to provide forward / reverse power. The suspension and guiding unit includes load-bearing wheel sets and lateral guide wheels. The load-bearing wheel sets (usually two or more pairs) are suspended from the lower flange of the track, bearing the entire weight of the robot 6 and its load. The lateral guide wheels clamp the track web or flange from both sides, preventing the robot 6 from lateral swaying or derailment, ensuring smooth operation. Power and communication are provided by a drag cable, sliding contact line, or battery. Real-time communication with the central controller is achieved wirelessly or via wired means, receiving commands and uploading status updates.

[0057] Multi-DOF downhole robotic arms typically employ a 6-DOF tandem articulated arm (capable of arbitrary position and orientation), or, to save cost and space, a 4-5 DDOF arm (sufficient for positioning and basic orientation adjustment). When a large working space is required, a composite structure combining a telescopic arm and rotary joints can be used. Driven by a fully hydraulic system (powered by the downhole pump station) or an explosion-proof servo motor, each joint incorporates a position / force sensor. A robot controller enables high-precision point-to-point or continuous trajectory control, and includes collision detection and compliant control capabilities.

[0058] The end effector can employ hydraulically or electrically driven parallel or arc-shaped grippers, lined with a high-friction coefficient material (such as polyurethane) to adapt to the side shape of the precast pier 5 and provide reliable gripping force. For precast pier 5 with a flat surface (such as a concrete slab), a vacuum suction cup array can be integrated to achieve rapid gripping and release without clamping stress.

[0059] The end effector can integrate a guide cone / sleeve, a fine-tuning mechanism, and a pin actuator. The guide cone / sleeve provides coarse positioning for the mating mechanisms (such as male and female tenons) of the upper and lower piers during placement. The fine-tuning mechanism, based on force / visual feedback, performs millimeter-level lateral micro-motion to compensate for alignment errors. The pin actuator is a retractable push rod or rotating mechanism used to insert the connecting pin into the aligned pin hole or tighten the connecting bolt.

[0060] The end effector can also integrate force / torque sensors (sensing gripping force, contact force, assembly resistance) and vision systems (camera and light source for identifying marks on the pier and measuring alignment deviations).

[0061] Thus, robot 6 replaces manual labor in dangerous goaf areas for handling, stacking, and connecting materials, keeping workers away from exposed roofs, dust, noise, and heavy physical labor. The combination of the robotic arm and the end effector enables the stacking and alignment accuracy of the precast piers 5 to reach the millimeter level, ensuring reliable connections and guaranteeing that the formed precast pier support columns 7 have good verticality and strong integrity, providing uniform and reliable support force.

[0062] In some embodiments, in step S3, the precast pier 5 is a standardized modular structure with interlocking mechanisms on its upper and lower surfaces. During assembly of the precast pier 5, the interlocking mechanisms of the upper and lower precast pier 5 are aligned and connected by the control of the precast pier transport and installation robot 6 to form a precast pier support column 7 that bears the overall load.

[0063] Interlocking mechanisms are used to achieve precise positioning, force transmission, and overall integration between prefabricated units through forced engagement of geometric shapes and mechanical connections.

[0064] The mechanisms themselves (such as the conical surface of the tenon and the inclined surface of the guide groove) provide physical guidance during the placement of robot 6. Even if there is a slight positioning error at the end of robot 6, these guide surfaces can generate a lateral force at the moment of contact, guiding the pier to slide into the correct position, achieving passive and precise positioning, and reducing the extreme requirements for the absolute positioning accuracy of robot 6.

[0065] Once the connection is complete, the interlocking mechanism transforms the transmission path of the interaction forces (mainly pressure, but also possibly shear force and bending moment) between the upper and lower piers from simple surface contact friction to the internal constraint force generated by the geometric interlocking, increasing the resistance to shear, torsion and tensile forces, and preventing the columns from slipping or shifting between layers under eccentric loading or vibration.

[0066] The mechanism design is matched to the functionality of the robot 6's end effector. Whether the robot 6 is required to perform insertion, rotation, or pressing actions, its motion trajectory and the required force / displacement curves are well-defined and programmable, making the automated assembly process predictable, controllable, and detectable.

[0067] Optionally, the interlocking mechanism can be a tenon and groove mating structure, with one or more protruding tenons (cylindrical, square, or dovetail-shaped) on the lower surface of the upper pier and a matching groove on the upper surface of the lower pier.

[0068] The interlocking mechanism can be a male-female connector pin structure, with ear plates or sleeves with alignment holes on the mating surfaces of the upper and lower piers. Robot 6 (or a special tool integrated into the end effector) inserts a separate connecting pin (or bolt) into the hole to complete the connection.

[0069] The interlocking mechanism can be a snap-fit ​​structure with a positioning guide surface, and hooks and slots with beveled surfaces are set on the side or corner of the pier. After the robot 6 places the upper pier, it needs to apply a small horizontal thrust or rotation to make the hooks slide into the slots and lock.

[0070] In practical design, these structures are often used in combination. For example, tenons and grooves are used to achieve main load-bearing and precise positioning, while pin holes are arranged at the four corners of the pier for shear reinforcement in key areas; or guide buckles are added to the side to assist in rapid initial positioning.

[0071] Furthermore, the end effector of the precast pier transport and installation robot 6 incorporates a force sensor and a vision positioning system to provide real-time feedback on alignment accuracy and connection status during the assembly process.

[0072] Force sensors monitor contact forces during assembly. For example, when inserting a tenon, the force curve will first rise (contact with the guide surface), then fall (slide in), and finally stabilize (in place). Abnormal force curves can provide real-time alerts for alignment misalignment or mechanism damage.

[0073] The visual positioning system can identify the position of the interlocking mechanism on the lower pier before placement, and perform final precise positioning compensation. The combination of sensors and interlocking mechanisms forms an intelligent closed loop of machine perception interface status - execution of precise operations - verification of connection results, ensuring automated assembly.

[0074] In some embodiments, in step S3, the constructed precast pier support columns 7 are arranged in a matrix or quincunx pattern in the goaf, with regular gaps between each precast pier support column 7.

[0075] For example, the support columns 7 are arranged in a grid pattern on the plan, forming a horizontally and vertically aligned, interconnected roadway-like or room-like grid space. The roof is simplified as a plate or beam supported by the surrounding coal pillars and the working face supports, with regular support points arranged below it. The support force is evenly distributed, and the bearing area of ​​each support column 7 is approximately a rectangle. The regular coordinates of the filling positions facilitate the central controller in generating fixed, repetitive work paths for the robot 6, simplifying the scheduling logic.

[0076] Alternatively, the support columns 7 can be distributed as equilateral triangles on the plan, meaning that the columns in each row are staggered by half a column spacing from the columns in the adjacent rows, forming a hexagonal honeycomb network. This results in a denser and more uniform distribution of support points. With the same column spacing, the maximum distance from any position in the quincunx arrangement to the nearest support column 7 is less than that in the matrix arrangement. With the same material consumption (the same number of support columns 7), it provides better roof stability and less subsidence, resulting in a higher cost-effectiveness of material utilization.

[0077] In some embodiments, after the mining and backfilling operation is completed, the gap space between the precast pier support columns 7 is sealed and reinforced to transform it into an underground storage facility for sealing carbon dioxide, storing compressed air or other materials.

[0078] For example, captured liquid or supercritical carbon dioxide can be pumped into a sealed interstitial space, where it can be permanently imprisoned underground by the pressure of the overlying rock strata and the low-permeability caprock. Furthermore, if the precast pier 5 or the surrounding rock contains active components (such as calcium and magnesium silicates), the carbon dioxide can react with them to form stable carbonate minerals, achieving permanent solidification.

[0079] Alternatively, during periods of surplus electricity (off-peak hours), a compressor injects high-pressure air into a sealed space; during periods of power shortage (peak hours), the high-pressure air is released to drive a turbine to generate electricity. Underground spaces are utilized as constant-temperature, constant-pressure, large-capacity gas storage tanks.

[0080] Alternatively, underground storage spaces can be used to store strategic resources such as oil, natural gas, and helium, or to dispose of specific wastes that have undergone stabilization treatment. Modifications are made according to the characteristics of the stored materials. For example, oil storage requires seepage and corrosion prevention; gas storage requires airtight reinforcement; and waste disposal requires multiple seepage barriers and monitoring systems.

[0081] In some embodiments, an environmental monitoring sensor is integrated on the top beam or tail beam of the filling hydraulic support 2 to monitor the roof pressure, delamination information and gas concentration of the goaf behind it in real time, and to feed the monitoring data back to the central controller for dynamically adjusting the arrangement density and assembly speed of the precast pier support columns 7 or triggering an early warning.

[0082] Understandably, multiple types of sensors are integrated on the top or tail beam of the filling hydraulic support 2 to monitor the key conditions of the goaf in a comprehensive and real-time manner.

[0083] Roof pressure sensors (such as vibrating wire or fiber optic pressure cells) are embedded between the support beam and the roof or above the tail beam to monitor the residual support pressure of the roof behind the goaf on the support or the load of collapsed rock strata. Their variation curves can reflect the roof activity patterns and periodic pressure conditions.

[0084] Roof delamination sensors (usually multi-point displacement gauges) are anchored in rock strata at different depths in the roof to monitor the separation displacement (delamination value) between rock strata, determine the integrity of the roof, and predict the risk of collapse.

[0085] Gas concentration sensors monitor the concentrations of gases such as oxygen, methane, carbon monoxide, and carbon dioxide behind the goaf for safety assurance (prevention of spontaneous combustion and gas accumulation) and environmental monitoring.

[0086] All sensor data is fed back to the central controller in real time via wired or wireless networks. The controller's algorithmic models (such as machine learning models based on historical data and rock strata movement theory models) fuse and analyze the data to determine the stability of the surrounding rock in the goaf in real time. For example: Stable state: Pressure is stable, delamination does not develop, and gas is normal.

[0087] Metastable state (early warning): Pressure rises slowly, delamination occurs and increases slowly.

[0088] Precursors to instability (alarms): rapid pressure changes, accelerated delamination, and the sound of micro-fractures (such as integrated microseismic monitoring).

[0089] Dangerous conditions: Gas levels exceed limits, signs of open flame appear (sudden increase in CO concentration).

[0090] Therefore, based on the precise response provided by the actual working conditions of the roof, support can be proactively strengthened at the initial stage of roof instability (such as the initial appearance of delamination). Unnecessary support is reduced in stable areas (optimized layout density), and support is strengthened in dangerous areas (densification or acceleration), minimizing the cost of backfill materials while ensuring safety.

[0091] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 simplifying the description, and are not intended to 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.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, an electrical connection, or a connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0094] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0095] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0096] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for coal backfilling mining using precast piers, characterized in that, include: S1. After the coal mining machine completes a coal mining operation in the fully mechanized mining face, the filling hydraulic support behind the coal mining machine is controlled to move forward in sequence to support the newly exposed roof. During the forward movement of the filling hydraulic support, the monorail at the tail of the filling hydraulic support is driven to extend forward synchronously, forming a dynamically moving material transport channel in the goaf area behind the fully mechanized mining face. S2, standardized precast piers are continuously transported to the working face by a precast pier transport and storage train arranged along the roadway, and the precast pier transport and installation robot running on the monorail is used to grab the precast piers from the transport and storage train and transport them to the designated filling position in the goaf. S3, at the designated filling location, control the precast pier transportation and installation robot to stack, align and assemble multiple precast piers layer by layer in the vertical direction to form a precast pier support column that provides stable support between the top and bottom plates of the goaf. S4. Repeat steps S1 to S3 to make the advancement of the fully mechanized mining face and the construction of the precast pier support columns proceed synchronously and cyclically until the mining and filling of the entire working face is completed.

2. The precast pier coal backfilling mining method according to claim 1, characterized in that, In step S1, the monorail is fixed to the tail beam or base of the filling hydraulic support in a detachable or hinged manner via a connector, so that it moves as a whole as the support pulls.

3. The precast pier coal backfilling mining method according to claim 1, characterized in that, In step S2, multiple precast pier transport and installation robots are set up to work collaboratively on the monorail track. The task allocation of each precast pier transport and installation robot is dynamically scheduled by the central controller based on the position of the transport and storage train, the progress of each filling position, and the real-time status of the robot.

4. The precast pier coal backfilling mining method according to claim 1 or 3, characterized in that, The precast pier transportation and installation robot includes a walking mechanism, a robotic arm, and an end effector. The walking mechanism is matched with the monorail track. The robotic arm is used for multi-degree-of-freedom movement. The end effector is a clamp with gripping, adsorption, or pin docking functions, used to grab and transport the precast piers and complete inter-layer alignment and connection.

5. The precast pier coal backfilling mining method according to claim 1, characterized in that, In step S3, the precast pier is a modular structure with a standardized design. Its upper and lower surfaces are equipped with interlocking mechanisms. When assembling the precast pier, the interlocking mechanisms of the upper and lower precast piers are aligned and connected by the control of the precast pier transport and installation robot to form the precast pier support column that bears the overall force.

6. The precast pier coal backfilling mining method according to claim 5, characterized in that, The interlocking mechanism is a tenon and groove mating structure, a male and female connector pin structure, or a snap-fit ​​structure with a positioning guide surface. The end effector of the precast pier transport and installation robot has a built-in force sensor and a vision positioning system, which are used to provide real-time feedback on alignment accuracy and connection status during the assembly process.

7. The precast pier coal backfilling mining method according to claim 1, characterized in that, In step S3, the constructed precast pier support columns are arranged in a matrix or quincunx pattern in the goaf, with regular gaps between each precast pier support column.

8. The precast pier coal backfilling mining method according to claim 7, characterized in that, After the mining and backfilling operations are completed, the gaps between the precast pier support columns are sealed and reinforced to transform them into underground storage facilities for sealing carbon dioxide, storing compressed air, or other materials.

9. The precast pier coal backfilling mining method according to claim 1, characterized in that, The top or tail beam of the filling hydraulic support is equipped with an environmental monitoring sensor to monitor the roof pressure, delamination information and gas concentration in the goaf behind it in real time. The monitoring data is fed back to the central controller to dynamically adjust the arrangement density and assembly speed of the precast pier support columns or to trigger an early warning.

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