A method for constructing a three-dimensional visualization model of the shaft wall of a main ore pass

Abstract

The present invention relates to the technical field of model construction, and specifically discloses a method for constructing a three-dimensional visualization model of the shaft wall of a main ore pass. The present invention obtains the ore unloading parameters of the shaft wall in real time based on a database and monitoring equipment, uses parametric modeling methods to establish a three-dimensional geometric model of the ore pass shaft wall, and discretizes the shaft wall into several grid units with material properties and initial damage states. It judges whether the movement trajectory of the ore block satisfies the shaft wall collision condition, conducts ore movement simulation in the three-dimensional geometric model, decomposes the velocity of the ore block when the ore block collides with the shaft wall, calculates the change in kinetic energy before and after the collision to obtain the impact energy, uses the Gaussian attenuation function to disperse part of the energy to the adjacent shaft wall grid units, calculates the damage increment of each shaft wall grid unit and accumulates it as the local damage value, and automatically adjusts the ore unloading flow through a feedback control algorithm, realizing the dynamic monitoring and control of the damaged state of the shaft wall, and effectively ensuring the safety of mine production.

Description

Technical Field

[0001] The present invention relates to the technical field of model construction, and more specifically, to a method for constructing a three-dimensional visualization model of the shaft wall of an ore main pass. Background Art

[0002] With the continuous expansion of the scale of mine exploitation and the rapid development of mining technology, the main pass, as a key passage for ore unloading and transportation, the safety and stability of its shaft wall structure have become important issues that need to be solved urgently in mine production. During the ore unloading process, due to the continuous impact of the high-speed fluid generated by the falling ore and the flowing material on the shaft wall, the local stress state of the shaft wall is complex, and it is extremely easy to form a local high-stress concentration area under high flow velocity and high flow rate conditions, resulting in local damage, spalling or even large-area collapse of the rock mass. The existing literature (Yin Yue, Lu Zengxiang, Ma Chi. Influence of the three-dimensional movement of ore and rock on the collision range of the main pass shaft wall [J]. Metal Mine, 2020, (11): 31-36. DOI: 10.19614 / j.cnki.jsks.202011005.) mentions that during the ore unloading process, when the ore and rock blocks enter the main pass from the inclined chute, their initial motion states (including velocity, direction angle, etc.) directly determine the collision position and the impacted area with the shaft wall, and gives a motion trajectory diagram of the ore block in the pass as shown in Figure 2 Since the high-speed movement and randomness of the ore and rock blocks, multiple impacts will cause cumulative damage to the shaft wall. By establishing a three-dimensional motion model of the ore and rock blocks, the impact range of the main pass shaft wall can be predicted and analyzed. The velocity magnitude and the initial direction angle of the ore when it enters the pass jointly determine its motion trajectory and the position of the first collision with the shaft wall. However, when the ore flow rate is high, although the pass structure parameters remain unchanged, the inertial effect during the collision is more obvious due to the high speed, which easily changes the distribution of the impact area, resulting in a higher or more concentrated impact area, thus affecting the force distribution of the shaft wall. When the ore flow rate is low, it will lead to a reduction in work efficiency, making it difficult to balance the ore unloading flow rate between ensuring high-efficiency production and shaft wall protection. To solve the above problems, a technical solution is provided now. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for constructing a three-dimensional visualization model of the shaft wall of an ore main pass, which combines the three-dimensional geometric model of the pass shaft wall with a feedback control algorithm to automatically adjust the ore unloading flow rate to solve the problem that it is difficult to balance the ore unloading flow rate between ensuring high-efficiency production and shaft wall protection, realizes the dynamic monitoring and control of the damaged state of the shaft wall, and effectively guarantees the safety of mine production, so as to solve the problems raised in the above background art.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for constructing a three-dimensional visualization model of a main ore chute wall comprises the following steps:

[0006] Step 1, obtaining the shaft wall unloading parameters in real time based on the database and monitoring equipment;

[0007] Step 2: Use a parametric modeling method to establish a three-dimensional geometric model of the shaft wall, and discretize the shaft wall into a number of grid units with material properties and initial damage states to determine whether the movement trajectory of the ore block meets the shaft wall collision condition;

[0008] Step 3, by simulating the movement of ore in a three-dimensional geometric model, when the ore block collides with the well wall, the velocity of the ore block is decomposed according to the coefficient of restitution, the change in kinetic energy before and after the collision is calculated, and the impact energy is obtained;

[0009] Step 4: Multiply the impact energy by the absorption rate of the well wall material and distribute it to the well wall grid unit where the collision point is located, and use the Gaussian attenuation function to disperse part of the energy to the adjacent well wall grid units, calculate the damage increment of each well wall grid unit and accumulate it as the local damage value; the well wall grid unit divides the well wall evenly according to the circumferential direction and height direction of the main chute, and divides it into Layer, divided into Layer; each well wall grid unit records its center coordinates and area;

[0010] Step 5, using 3D graphics rendering technology and color mapping to display the real-time damage value of each grid cell of the well wall in the form of a heat map, and at the same time animating the movement trajectory of the ore block and the collision event;

[0011] Step 6, according to the real-time damage data and collision frequency of each area of ​​the well wall, the unloading flow rate is automatically adjusted through the feedback control algorithm to achieve real-time closed-loop control of the unloading flow rate.

[0012] As a further solution of the present invention, in step 1, the well wall unloading parameters include well wall parameters and unloading parameters; the well wall parameters include diameter and well depth; the unloading parameters include unloading flow rate and unloading time.

[0013] As a further solution of the present invention, in step 2, it is determined whether the motion trajectory of the ore block meets the well wall collision condition, and the specific steps are:

[0014] Step 21, by taking a time step during the unloading period Calculate the trajectory of the ore block, based on each time step The position coordinates of the ore block construct the first motion trajectory coordinate set , summarize the first motion trajectory coordinate set of all ore blocks Get the first trajectory sequence , where the location coordinates of the ore block are:

[0015] ;

[0016] ;

[0017] ;

[0018] In the formula: is the coordinate of the ore block in the x - direction at time , is the coordinate of the ore block in the y - direction at time , represents the coordinate of the ore block in the z - direction at time , is the coordinate of the ore block in the x - direction at the current moment t, is the coordinate of the ore block in the y - direction at the current moment t, is the coordinate of the ore block in the z - direction at the current moment t, is the initial velocity when the ore block enters the ore - discharging area, is the angle between the initial velocity of the ore block and the horizontal direction, is the deflection angle of the initial movement direction of the ore block in the horizontal plane, is the time step, is the gravitational acceleration;

[0019] Step 22: According to the first trajectory sequence , determine whether the movement trajectory of the ore block satisfies the shaft - wall collision condition. The shaft - wall collision condition is judged according to the projection of the ore - block movement trajectory on the horizontal plane. The judgment formula for the shaft - wall collision condition is:

[0020] ;

[0021] In the formula: is the coordinate of the ore block in the x - direction at time is the coordinate of the ore block in the y - direction at time is the shaft - wall diameter;

[0022] Step 23: When all the first - movement - trajectory coordinate sets of the ore block satisfy the shaft - wall collision condition, it indicates that the ore block does not collide with the shaft wall; when there are first - movement - trajectory coordinate sets of the ore block that do not satisfy the shaft - wall collision condition, it indicates that the ore block collides with the shaft wall.

[0023] As a further solution of the present invention, in step 3, when the ore block collides with the shaft wall, decompose the velocity of the ore block according to the coefficient of restitution, calculate the change in kinetic energy before and after the collision, and obtain the impact energy, specifically:

[0024] Step 31: Decompose the velocity of the ore block into a normal component and a tangential component, and obtain the normal incident velocity at the moment of collision as , and the tangential incident velocity as . Calculate the normal velocity component and the tangential velocity component of each ore block when it leaves after the collision in real time. Then the velocity components of the ore block when it leaves after the collision are:

[0025] ;

[0026] ;

[0027] ;

[0028] In the formula: is the normal velocity component of the ore block when it leaves after the collision, is the tangential velocity component of the ore block when it leaves after the collision, is the normal restitution coefficient, is the normal incident velocity at the moment of collision, is the tangential restitution coefficient, is the tangential incident velocity at the moment of collision;

[0029] Step 32: Calculate the impact energy released by the collision according to the kinetic energy difference before and after the collision:

[0030] ;

[0031] In the formula: is the impact energy released by the collision, is the velocity of the ore block before the collision with the shaft wall, is the velocity of the ore block when it leaves after the collision, is the mass of the ore block.

[0032] As a further solution of the present invention, in Step 4, multiply the impact energy by the absorption rate of the shaft wall material and distribute it to the shaft wall grid unit where the collision point is located, and use the Gaussian attenuation function to disperse part of the energy to the adjacent units, and calculate the damage increment of each shaft wall grid unit and accumulate it as the local damage value. The specific steps are as follows:

[0033] Step 41: At each collision, multiply the impact energy released by the collision by the energy absorption rate of the shaft wall material as the actual transmitted energy to the local shaft wall for this collision;

[0034] Step 42: Each grid unit of the shaft wall three-dimensional model is given an initial damage value of zero during initialization, and the damage increment is calculated according to the following formula when the collision occurs:

[0035] ;

[0036] In the formula: is the damage increment, is the actual transmitted energy of the collision to the local wellbore wall, is the collision energy threshold, indicates that if , the result is zero; if , the result is ;

[0037] Step 43: Use a Gaussian attenuation function to allocate the actual transmitted energy of the collision to the local wellbore wall among the collision point and its adjacent wellbore grid cells. Select the collision point located in the wellbore grid cell and the wellbore grid cells in its neighborhood, and calculate the local damage value of each wellbore grid cell in its neighborhood;

[0038] Step 44: After each collision, update the cumulative damage value of the corresponding wellbore grid cell, and record the collision position, occurrence time, impact energy, and the updated cumulative damage value at the same time to form a collision event log.

[0039] As a further solution of the present invention, in Step 43, the local damage value of each wellbore grid cell in the neighborhood is obtained by multiplying the damage increment by an attenuation factor . The attenuation factor is used to reflect the distance effect between the collision point and the center of the adjacent cell, being the standard deviation of the Gaussian attenuation function.

[0040] As a further solution of the present invention, in Step 5, use three-dimensional graphics rendering technology and color mapping to display the real-time damage values of each wellbore grid cell in the form of a heat map, and render the wellbore grid cells and ore blocks;

[0041] Rendering of wellbore grid cells: Draw the wellbore grid cells. The initial color can be set to gray. When there is damage data, apply color mapping to each wellbore grid cell: According to the damage increment, map it to blue for 0 damage and red for the maximum damage, and perform gradient interpolation to form a real-time changing heat map. The heat map can be overlaid with a certain transparency so that both the wellbore structure and the damage distribution can be seen. For the areas that have not been impacted, keep the background color; as the simulation progresses, the colors of the cells will change continuously. For example, when a certain place is impacted frequently, the color will gradually evolve from blue → green → yellow → red, and the user can clearly understand the damage hot spots.

[0042] ​Ore block rendering: Render moving ore blocks as particles or entities. When represented simply, small balls or polyhedra can be used to represent ore blocks. For enhanced perception during rendering, motion trails or velocity vector arrows can be given according to the ore block's speed to assist in the display. The color of the ore blocks can also be encoded, for example, using a unified color to distinguish from the shaft wall, or changing in shade according to the speed magnitude (bright color at high speed, dark color at low speed). When the ore blocks collide instantaneously, a flash or special mark can be made on the graph for prompt. For example, briefly flashing a small spark effect indicates a violent collision, enabling users to intuitively capture the location and time of the collision event.

[0043] Technical effects and advantages of the method for constructing a three-dimensional visualization model of the shaft wall of the main ore chute in the present invention: Based on the database and monitoring equipment, the present invention obtains the ore discharge parameters of the shaft wall in real time, uses the parametric modeling method to establish a three-dimensional geometric model of the chute shaft wall, and discretizes the shaft wall into several grid units with material properties and initial damage states, determines whether the movement trajectory of the ore block satisfies the shaft wall collision condition, conducts ore movement simulation in the three-dimensional geometric model, decomposes the ore block speed when the ore block collides with the shaft wall, calculates the change in kinetic energy before and after the collision to obtain the impact energy, uses the Gaussian attenuation function to disperse part of the energy to adjacent shaft wall grid units, calculates the damage increment of each shaft wall grid unit and accumulates it as the local damage value, and automatically adjusts the ore discharge flow through the feedback control algorithm, realizing the dynamic monitoring and control of the damaged state of the shaft wall, and effectively ensuring the safety of mine production. Brief Description of the Drawings

[0044] Figure 1 It is the three-dimensional visualization and real-time monitoring interface provided by the present invention;

[0045] Figure 2 It is the movement trajectory diagram of the ore block in the chute provided by the present invention;

[0046] Figure 3 It is the schematic flow chart of the method for constructing a three-dimensional visualization model of the shaft wall of the main ore chute provided by the present invention;

[0047] Figure 4 It is the schematic flow chart of step 2 in the method for constructing a three-dimensional visualization model of the shaft wall of the main ore chute provided by the present invention;

[0048] Figure 5 It is the schematic flow chart of step 3 in the method for constructing a three-dimensional visualization model of the shaft wall of the main ore chute provided by the present invention;

[0049] Figure 6 It is the schematic flow chart of step 4 in the method for constructing a three-dimensional visualization model of the shaft wall of the main ore chute provided by the present invention. Detailed Embodiments

[0050] The following will clearly and completely describe the technical solutions in the present invention in conjunction with the accompanying drawings in the present invention. Obviously, the described technical solutions are only a part of the present invention, rather than all of it. Based on the technical solutions in the present invention, all other technical solutions obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0051] Embodiment 1

[0052] Figure 3 It is a schematic flow chart of a method for constructing a three-dimensional visualization model of the shaft wall of a main ore pass in the present invention. As shown in the figure, a method for constructing a three-dimensional visualization model of the shaft wall of a main ore pass includes the following steps:

[0053] Step 1: Based on the database and monitoring equipment, the ore discharge parameters of the shaft wall are obtained in real time.

[0054] Step 2: Use the parametric modeling method to establish a three-dimensional geometric model of the ore pass shaft wall, and discretize the shaft wall into several grid units with material properties and initial damage states, and judge whether the movement trajectory of the ore block meets the shaft wall collision condition.

[0055] Step 3: Through ore movement simulation in the three-dimensional geometric model, when the ore block collides with the shaft wall, decompose the velocity of the ore block according to the restitution coefficient, calculate the change in kinetic energy before and after the collision, and obtain the impact energy.

[0056] Step 4: Multiply the impact energy by the absorption rate of the shaft wall material and distribute it to the shaft wall grid unit where the collision point is located, and use the Gaussian attenuation function to disperse part of the energy to the adjacent shaft wall grid units, calculate the damage increment of each shaft wall grid unit and accumulate it as the local damage value; the shaft wall grid units evenly divide the shaft wall in the circumferential direction and height direction of the main ore pass, and are divided into layers along the wall height and layers along the circumference; each shaft wall grid unit records its central coordinates and area.

[0057] Step 5: Use three-dimensional graphics rendering technology and color mapping to display the real-time damage values of each grid unit of the shaft wall in the form of a heat map, and at the same time display the movement trajectory of the ore block and the collision event in an animated manner.

[0058] Step 6: According to the real-time damage data and collision frequency of each area of the shaft wall, automatically adjust the ore discharge flow through the feedback control algorithm to achieve real-time closed-loop control of the ore discharge flow.

[0059] It should be noted that for the modeling of ore blocks: Ore blocks can be regarded as moving rigid body entities. The ore source may be a continuous flow (such as continuous ore discharge from a bunker gate) or discrete batches (a batch of ore drops every certain period). For simulation convenience, an ore generator can be defined at the wellhead to generate ore blocks according to the set flow rate or time series. In terms of the shape of ore blocks, for simplicity of calculation, approximate spherical or cubic shapes are usually adopted. In DEM simulation, equivalent diameter spheres are commonly used to represent irregular crushed stones. Of course, the fidelity can also be improved by using polyhedrons or irregular shapes (such as forming blocks by clustering spheres). This model supports ore blocks of different particle sizes to reflect the ore size distribution. If the influence of particle size on collisions is to be considered, the diameter of ore blocks can be set to follow a certain statistical distribution (such as normal, lognormal, or the distribution obtained from actual screening), and randomly selected when generating ore blocks. The mass of ore blocks is calculated based on their volume and density. The density of ore blocks is usually known, and a unified ore density can be set in the model or a slight perturbation can be given to different ore blocks.

[0060] The ore motion simulation adopts a time-stepping method: within the time step , the accelerations, velocities, and displacements of all active ore blocks are calculated, and whether new collisions occur is detected. If an ore block is within the wellbore wall surface, it is determined that a collision event has occurred, and the collision response needs to be calculated (modifying the velocity according to the aforementioned collision mechanics model and generating impact data). Since the wellbore wall is a fixed boundary, the detection of the collision between the ore block and the wellbore wall is relatively simple: as long as the distance from the center of the ore block to the center of the shaft is less than the shaft radius, it means the ore block has entered the wall; further considering the size of the ore block, it can be determined that the surface of the ore block contacts the wall surface.

[0061] Whenever a collision occurs, record the wellbore grid cell where the collision occurs and the impact energy, and perform a damage accumulation algorithm update on this wellbore grid cell. At the same time, calculate the rebound trajectory of the ore block according to the velocity after the collision. If the velocity of the ore block is still large after rebounding, it may hit the opposite wellbore wall again, so that an ore block may experience multiple collisions until the velocity decreases and finally slides to the bottom of the ore pass. The simulation will continue until the ore block reaches the bottom outlet (or the velocity approaches zero and stays at the bottom of the well). Then, if necessary, this ore block can be removed from the simulation (equivalent to falling into a ore car or conveyor belt), and new ore blocks are continuously generated and input to achieve the simulation of continuous flow.

[0062] Specifically, in step 1, the wellbore ore unloading parameters include wellbore parameters and ore unloading parameters; the wellbore parameters include diameter and well depth; the ore unloading parameters include ore unloading flow rate and ore unloading duration.

[0063] Figure 4 This is a schematic flow diagram of step 2 in the method for constructing a three-dimensional visualization model of the wellbore wall of the main ore pass of the present invention. As shown in the figure, in step 2, it is judged whether the movement trajectory of the ore block meets the wellbore collision condition. The specific steps are as follows:

[0064] Step 21, calculate the movement trajectory of the ore blocks at a time step within the ore unloading period, and construct a first movement trajectory coordinate set according to the position coordinates of each ore block at each time step and summarize the first movement trajectory coordinate sets of all ore blocks to obtain a first trajectory sequence , where the position coordinates of the ore block are: ;

[0065] ;

[0066] ;

[0067] ;

[0068] In the formula: is the coordinate of the ore block in the x direction at time , is the coordinate of the ore block in the y direction at time , represents the coordinate of the ore block in the z direction at time , is the coordinate of the ore block in the x direction at the current time t, is the coordinate of the ore block in the y direction at the current time t, is the coordinate of the ore block in the z direction at the current time t, is the initial velocity of the ore block when it enters the ore unloading area, is the angle between the initial velocity of the ore block and the horizontal direction, is the deflection angle of the initial movement direction of the ore block in the horizontal plane, is the time step, is the gravitational acceleration;

[0069] Step 22, judge whether the movement trajectory of the ore block meets the shaft wall collision condition according to the first trajectory sequence . The shaft wall collision condition is judged according to the projection of the ore block movement trajectory on the horizontal plane. The judgment formula for the shaft wall collision condition is:

[0070] ;

[0071] In the formula: is the coordinate of the ore block in the x direction at time , is the coordinate of the ore block in the y direction at time , is the shaft wall diameter;

[0072] ​Step 23, when the first motion trajectory coordinate sets of the ore block all meet the well wall collision condition, it indicates that the ore block has not collided with the well wall; when there is a first motion trajectory coordinate set of the ore block that does not meet the well wall collision condition, it indicates that the ore block has collided with the well wall.

[0073] Through step 1, the geometric parameters of the shaft wall (diameter, shaft depth) and the unloading parameters (unloading flow rate, unloading time) are obtained from the database and monitoring equipment in real time to ensure that the input data of the model always reflects the actual working conditions on site, which helps to improve the accuracy of simulation and judgment; the motion trajectory of the ore block in the unloading process is calculated using discrete time steps to form a first motion trajectory coordinate set, and the first trajectory sequence is generated by summarizing, so that the entire motion process can be simulated finely, and every position change of the ore block in the motion process can be captured, which is convenient for subsequent collision judgment and energy calculation; collision detection is simplified by judging the position coordinates of the ore block on the horizontal plane. Since the shaft wall is usually a cylinder, using horizontal projection to judge whether it enters the shaft wall area is an intuitive and efficient method. When all coordinates in the first trajectory sequence meet the collision conditions, it can be quickly determined that the ore block has not collided with the well wall; conversely, once there are coordinates that do not meet the conditions, the collision event can be captured in time, which is convenient for the subsequent calculation of impact energy and well wall damage; using discrete time steps for trajectory calculation can not only maintain simulation accuracy, but also quickly determine the collision state through simple conditional judgment, thereby reducing calculation complexity; after determining the collision point, the impact energy can be further calculated using the change in kinetic energy before and after the collision, and the energy can be apportioned using the Gaussian attenuation function according to subsequent steps to calculate the damage of each grid unit of the well wall. The step-by-step implementation strategy enables the entire system to form a complete closed-loop control system from parameter acquisition, trajectory calculation, collision detection, energy distribution to damage accumulation.

[0074] Figure 5 The present invention provides a flow chart of step 3 in a method for constructing a three-dimensional visualization model of a main ore chute wall. As shown in the figure, in step 3, when an ore block collides with the shaft wall, the velocity of the ore block is decomposed according to the coefficient of restitution, and the change in kinetic energy before and after the collision is calculated to obtain the impact energy, specifically:

[0075] Step 31, decompose the velocity of the ore block into a normal component (perpendicular to the well wall surface at the collision point) and a tangential component (parallel to the well wall surface), and obtain the normal incident velocity at the moment of collision: , the tangential incident velocity is , then the velocity component of the ore block when it leaves after collision is:

[0076] ;

[0077] ;

[0078] ;

[0079] In the formula: is the normal velocity component when the ore block leaves after collision, is the tangential velocity component when the ore block leaves after collision, is the normal restitution coefficient, is the normal incident velocity at the moment of collision, is the tangential restitution coefficient, is the tangential incident velocity at the moment of collision;

[0080] Step 32, calculate the impact energy released by the collision according to the kinetic energy difference before and after the collision:

[0081] ;

[0082] In the formula: is the impact energy released by the collision, is the velocity of the ore block before colliding with the shaft wall, is the velocity of the ore block when it leaves after the collision, is the mass of the ore block.

[0083] Figure 6 This is the flow chart of step 4 in the method for constructing a three-dimensional visualization model of the shaft wall of the main ore pass provided by the present invention. As shown in the figure, in step 4, multiply the impact energy by the absorption rate of the shaft wall material and distribute it to the shaft wall grid unit where the collision point is located, and use the Gaussian attenuation function to disperse part of the energy to adjacent units, calculate the damage increment of each shaft wall grid unit and accumulate it as the local damage value. The specific steps are as follows:

[0084] Step 41, in each collision, the impact energy released by the collision is multiplied by the energy absorption rate of the shaft wall material as the actual transmitted energy to the local shaft wall for this collision:

[0085] ;

[0086] Step 42, the grid units of the three-dimensional model of the shaft wall are all given an initial damage value of zero during initialization, and the damage increment is calculated according to the following formula when a collision occurs:

[0087] ;

[0088] In the formula: is the damage increment, is the actual transmitted energy to the local shaft wall by the collision, is the collision energy threshold, It means that effective damage energy is generated only when the actually transferred energy exceeds the collision energy threshold, and the excess part contributes to the destruction;

[0089] Step 43: Use a Gaussian attenuation function to allocate the actually transferred energy of the collision to the local wellbore wall at the collision point and its adjacent wellbore grid cells, and select the collision point located in the wellbore grid cell of and the wellbore grid cells within its neighborhood of the collision point. Then, the local damage value of each wellbore grid cell within its neighborhood is:

[0090] ;

[0091] In the formula: is the local damage value caused by the collision event to the wellbore grid cell , is the damage increment obtained by the grid cell where the collision point is located, is the central coordinate of the wellbore grid cell where the collision point is located, is the central coordinate of the wellbore grid cell where the collision point

[0092] Step 44: After each collision, update the cumulative damage value of the corresponding wellbore grid cell, and at the same time record the collision position, occurrence time, impact energy, and the updated cumulative damage value to form a collision event log.

[0093] By decomposing the velocity of the ore block into a normal component (perpendicular to the wellbore wall) and a tangential component (parallel to the wellbore wall), and using the restitution coefficient to correct the velocity after the collision respectively, the model can accurately reflect the energy loss and velocity attenuation during the collision process, so as to calculate the change in kinetic energy before and after the collision. Multiply the energy released by the collision by the absorption rate of the wellbore wall material, and use the actually transferred energy to the wellbore wall as the basis for damage assessment. This not only takes into account the energy absorption ability of the material but also avoids the unreasonable assumption of full energy transfer. Use a Gaussian attenuation function to allocate the collision energy from the collision point to the adjacent wellbore grid cells, and the energy distribution conforms to the physical characteristics of energy transfer in reality: the area near the collision point is most significantly affected, and the farther away, the smaller the impact. After each collision, the system automatically updates the cumulative damage value of the corresponding wellbore grid cell, and records the collision position, occurrence time, and impact energy to form a detailed collision event log, providing a reliable data basis for subsequent monitoring, analysis, and feedback control. Recording detailed collision logs not only helps to monitor the wellbore wall state in real time but also can be used for later statistical analysis, model calibration, and optimization of the early warning mechanism.

[0094] Specifically, in step 6, the real-time damage values of each grid cell of the shaft wall are displayed in the form of a heat map using 3D graphics rendering technology and color mapping. At the same time, the movement trajectories and collision events of the ore blocks are shown in animation, which specifically includes shaft wall grid cell rendering and ore block rendering.

[0095] Shaft wall grid cell rendering: Draw the shaft wall grid cells. The initial color can be set to gray. When there is damage data, apply color mapping to each shaft wall grid cell: According to the damage increment, map it to blue for 0 damage and red for the maximum damage, and perform gradient interpolation to form a real-time changing heat map. The heat map can be superimposed with a certain transparency so that both the shaft wall structure and the damage distribution can be seen. For areas that have not been impacted, keep the background color. As the simulation progresses, the colors of the cells will continuously change. For example, when a certain location is frequently impacted, the color will gradually evolve from blue → green → yellow → red, enabling users to clearly understand the damage hot spots at a glance.

[0096] Ore block rendering: Render the moving ore blocks as particles or entities. When simply represented, small balls or polyhedrons can be used to represent the ore blocks. To enhance perception during rendering, motion trails or velocity vector arrows can be given according to the ore block speed for auxiliary display. The colors of the ore blocks can also be encoded, such as using a unified color to distinguish them from the shaft wall, or changing in depth according to the speed magnitude (bright color for high speed and dark color for low speed). When a collision occurs between the ore blocks, a flash or special mark can be made on the graph for prompt. For example, briefly flash a small spark effect to indicate a violent collision, enabling users to intuitively capture the location and time of the collision event.

[0097] Specifically, in step 7, according to the real-time damage data and collision frequencies of each area of the shaft wall, automatically adjust the ore unloading flow rate through a feedback control algorithm to achieve real-time closed-loop control of the ore unloading flow rate.

[0098] Step 71: By real-time monitoring the local damage values and collision frequencies of each shaft wall grid cell, obtain key control indicators, including the maximum local damage value and the actual transmitted energy to the local shaft wall for each collision per unit time.

[0099] Step 72: Set the target local damage value and the transmitted energy threshold. When the maximum local damage value is greater than the target local damage value or the actual transmitted energy is greater than the transmitted energy threshold, the control module automatically reduces the ore block unloading flow rate. When the maximum local damage value is less than the target local damage value or the actual transmitted energy is less than the transmitted energy threshold, the control module automatically increases the ore block unloading flow rate.

[0100] Figure 1The 3D visualization and real-time monitoring interface provided by the present invention for the main ore pass can display the damage condition of the shaft wall and the movement state of ore blocks in real time. The left side of the interface is the parameter control and monitoring area, where the height of ore blocks and the ore unloading flow can be adjusted, and the current damage progress, collision frequency, and collision energy are displayed. The right side is a 3D graphics rendering window, which visually presents the local damage distribution of the shaft wall through color mapping (heat map). The red area represents a higher degree of damage, and the blue area represents a lower degree of damage. The "Start", "Pause", and "Stop" buttons below enable dynamic operation of the simulation or monitoring process. The overall interface not only facilitates the operator to adjust the ore unloading process but also can monitor and give early warnings of the safety state of the shaft wall in real time, thus effectively ensuring the safety of mine production and the shaft wall structure.

[0101] Example 2

[0102] Taking the main ore pass of a certain underground mine as an example, the following shaft wall ore unloading parameters are given. The shaft wall ore unloading parameters include shaft wall parameters and ore unloading parameters. The shaft wall parameters include a diameter of 5.0 m, a shaft depth of 70 m, and the shaft wall is divided into 14 layers (each layer is 5 m) in the height direction and 20 grid units in the circumferential direction, for a total of 14×20 = 280 grid units. The ore unloading parameters include an ore unloading flow of 5 blocks per second and an ore unloading duration of 60 s.

[0103] An ore block is generated by an ore generator at t = 0, and its initial coordinates are set at the shaft opening (x(0)=0, y(0)=0, z(0)=0), with an initial velocity of 7.67 m / s, an elevation angle of 30°, and an azimuth angle of 45°. After several time step calculations, when its horizontal distance reaches D / 2 = 2.5 m, it is determined that a collision occurs. Assuming that at t = 3.2 s, the position of the ore block is:

[0104] , , ;

[0105] The detection condition is satisfied ( ), so it is determined that a collision occurs, and the collision point is located in the grid unit corresponding to the shaft wall, and the center coordinates of this unit may be (3.0 m, 3.0 m, 15.0 m).

[0106] At the moment of collision, the velocity of the ore block is decomposed. Assuming the normal incident velocity = 5.0 m / s and the tangential incident velocity = 6.0 m. The velocity after collision is:

[0107] ;

[0108] ;

[0109] ;

[0110] The velocity before collision \(v\approx7.67\,m / s\), then the change in kinetic energy is:

[0111] ;

[0112] Multiply by the absorption rate of the shaft wall material (0.8) to obtain the actual transmitted energy:

[0113] ;

[0114] Preset , and according to the damage increment calculation formula, we get , which means that within the grid cell \(G(i,j)\) where the collision point is located, this collision results in a damage increment of 4.26 (unit: dimensionless value).

[0115] Use the Gaussian attenuation function to distribute this part of the energy in the neighborhood. Select the collision point located in the shaft wall grid cell and the shaft wall grid cell at a distance of 0.5 m in its neighborhood , then the local damage value of each shaft wall grid cell in its neighborhood is:

[0116] ;

[0117] For the grid cell at a distance of 1.0 m, , and calculate successively in this way. The damage increment obtained by each neighboring grid cell decays according to the distance, and finally this collision is distributed locally to update the cumulative damage value of each grid cell.

[0118] After each collision, the system records the collision event log, including the collision occurrence time, the central coordinates of the grid cell \(G(i,j)\) where the collision point is located, the impact energy and actual transmitted energy released by the collision, the damage increment calculated by the collision, and the damage increment distributed to each neighboring grid cell using the Gaussian distribution and the updated cumulative damage value. An example table of part of the collision event log after 60 s of simulation is shown in Table 1:

[0119]

[0120] Table 1 Example table of part of the collision event log after 60 s of simulation

[0121] Among them, the "highest neighborhood damage value" is the damage value obtained by the cell where the collision point is located, and other neighborhood cells obtain lower damage values according to different distances.

[0122] Through 3D graphics rendering technology, color mapping is performed on the real-time cumulative damage values of each grid cell on the shaft wall. Initially, the color of all grid cells is grayish blue (damage value is 0). As the simulation progresses, if the cumulative damage in a certain area gradually increases due to frequent collisions, the color gradually transitions from blue to green, yellow, and finally to red. For example, in the collision hot spot area, the cumulative damage value may reach 5.0 after continuous collisions, and this area will be displayed as dark red.

[0123] At the same time, the movement trajectories of the ore blocks are displayed in an animated way. After each ore block is generated at the wellhead, its position is continuously updated according to the movement trajectory; when a collision occurs, the collision point flashes and the collision direction and rebound trajectory are marked. Such an animated effect enables engineers to intuitively observe the spatial distribution and evolution process of the shaft wall damage during the ore unloading process.

[0124] During the entire simulation process, the system statistically calculates the maximum cumulative damage value and the average damage value of each area of the current shaft wall at regular intervals (every 10 s). For example, after the first 10 s of simulation, the maximum cumulative damage value may be 0.8, and the error at this time is -0.2; indicating that the shaft wall state is still safe, so the ore unloading flow rate is not adjusted;

[0125] At 20 s, if the maximum cumulative damage value reaches 1.2 and the error is 0.2, the PID controller is triggered to output a positive signal, causing the system to lower the ore unloading flow rate.

[0126] As the flow rate decreases, the collision frequency decreases, and the growth rate of the cumulative damage of the shaft wall slows down; when the local damage value returns to the safe level (for example, below 1.0), the controller allows the flow rate to increase appropriately, thus realizing real-time closed-loop regulation of the ore unloading flow rate.

[0127] The data change data table of the flow rate regulation process within 60 s of simulation is shown in Table 2:

[0128]

[0129] Table 2 Data change data table of the flow rate regulation process within 60 s of simulation

[0130] In the embodiments of the present invention, the ore unloading parameters of the shaft wall are obtained in real time based on a database and monitoring devices. A three-dimensional geometric model of the ore pass shaft wall is established by using a parametric modeling method, and the shaft wall is discretized into a number of grid elements with material properties and initial damage states. It is judged whether the movement trajectory of the ore block meets the shaft wall collision condition. By performing ore movement simulation in the three-dimensional geometric model, when the ore block collides with the shaft wall, the velocity of the ore block is decomposed, the change in kinetic energy before and after the collision is calculated to obtain the impact energy, part of the energy is dispersed to the adjacent shaft wall grid elements by using a Gaussian attenuation function, the damage increment of each shaft wall grid element is calculated and accumulated as a local damage value, and the ore unloading flow rate is automatically adjusted through a feedback control algorithm, realizing the dynamic monitoring and control of the damaged state of the shaft wall and effectively ensuring the safety of mine production.

[0131] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

[0132] Finally: The above description is only the preferred solution of the present invention and is not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for constructing a three-dimensional visualization model of a main ore chute wall, characterized in that: The steps include: Step 1, obtaining the shaft wall unloading parameters in real time based on the database and monitoring equipment; Step 2: Use parametric modeling methods to establish a three-dimensional geometric model of the shaft wall, and discretize the shaft wall into a number of grid units with material properties and initial damage states to determine whether the motion trajectory of the ore block meets the shaft wall collision condition. The specific steps are as follows: Step 21, by taking a time step during the unloading period Calculate the trajectory of the ore block, based on each time step The position coordinates of the ore block construct the first motion trajectory coordinate set , summarize the first motion trajectory coordinate set of all ore blocks Get the first trajectory sequence ; Step 22: According to the first trajectory sequence Determine whether the motion trajectory of the ore block meets the well wall collision condition. The well wall collision condition is determined based on the projection of the motion trajectory of the ore block on the horizontal plane. The judgment formula for the well wall collision condition is: ； Where: for The x-coordinate of the ore block at the moment, for The y coordinate of the ore block at the moment, is the diameter of the wellbore; Step 23, when the first motion trajectory coordinate sets of the ore block all meet the well wall collision condition, it indicates that the ore block has not collided with the well wall; when there is a first motion trajectory coordinate set of the ore block that does not meet the well wall collision condition, it indicates that the ore block has collided with the well wall; Step 3, by simulating the movement of ore in a three-dimensional geometric model, when the ore block collides with the well wall, the velocity of the ore block is decomposed according to the coefficient of restitution, the change in kinetic energy before and after the collision is calculated, and the impact energy is obtained; Step 4: Multiply the impact energy by the absorption rate of the well wall material and distribute it to the well wall grid unit where the collision point is located, and use the Gaussian attenuation function to disperse part of the energy to the adjacent well wall grid units, calculate the damage increment of each well wall grid unit and accumulate it as the local damage value. The specific steps are as follows: Step 41, at each collision, the impact energy released by the collision Multiply by the energy absorption rate of the wellbore material , as the actual energy transferred by the collision to the local wellbore wall ; Step 42, the grid cells of the three-dimensional model of the wellbore are all assigned an initial damage value of zero during initialization, and when a collision occurs, the damage increment is calculated according to the following formula: ； Where: is the damage increment, is the actual energy transferred by the collision to the local wellbore wall, is the collision energy threshold, If , the result is zero; if , the result is ; Step 43, using a Gaussian attenuation function, the actual energy transferred by the collision to the local well wall is apportioned among the collision point and its adjacent well wall grid cells, and the well wall grid cells located at the well wall are selected. The collision point and the well wall grid cells in its neighborhood The collision point , calculate the local damage value of each wellbore grid cell in its neighborhood; Step 44, after each collision, the cumulative damage value of the corresponding well wall grid unit is updated, and the collision position, occurrence time, impact energy and updated cumulative damage value are recorded to form a collision event log; Step 5, using 3D graphics rendering technology and color mapping to display the real-time damage value of each grid cell of the well wall in the form of a heat map, and at the same time animating the movement trajectory of the ore block and the collision event; Step 6, according to the real-time damage data and collision frequency of each area of ​​the well wall, the unloading flow rate is automatically adjusted through the feedback control algorithm to achieve real-time closed-loop control of the unloading flow rate.

2. A method for constructing a three-dimensional visualization model of a main ore chute wall according to claim 1, characterized in that: In step 1, the well wall unloading parameters include well wall parameters and unloading parameters; the well wall parameters include diameter and well depth; the unloading parameters include unloading flow rate and unloading time.

3. The method for constructing a three-dimensional visualization model of a main ore chute wall according to claim 1, characterized in that: In step 3, when the ore block collides with the well wall, the velocity of the ore block is decomposed according to the coefficient of restitution, the change in kinetic energy before and after the collision is calculated, and the impact energy is obtained, specifically: Step 31, decompose the velocity of the ore block into a normal component and a tangential component, and obtain the normal incident velocity at the moment of collision: , the tangential incident velocity is , calculate in real time the normal velocity component and tangential velocity component of each ore block when it leaves after collision; Step 32, calculating the impact energy released by the collision according to the kinetic energy difference before and after the collision.

4. The method for constructing a three-dimensional visualization model of a main ore chute wall according to claim 1, characterized in that: In step 43, the local damage value of each wellbore grid cell in the neighborhood is The damage increment is multiplied by a decay factor The attenuation factor is used to reflect the distance effect between the collision point and the center of the adjacent unit. is the standard deviation of the Gaussian decay function.

5. The method for constructing a three-dimensional visualization model of a main ore chute wall according to claim 1, characterized in that: In step 5, the real-time damage value of each grid cell of the well wall is displayed in the form of a heat map using three-dimensional graphics rendering technology and color mapping. The well wall grid cells and ore blocks are rendered, and the well wall grid cells are drawn. The initial color is set to gray. When there is a local damage value, color mapping is applied to each well wall grid cell. According to the damage increment, it is mapped to blue for 0 damage and red for maximum damage.

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