Bulk material unmanned automatic stacking and unstacking transfer method and system

Abstract

The present application relates to material transfer technical field, disclose a kind of bulk material unmanned automatic stacking and taking transfer method and system, comprising: the three-dimensional point cloud data of acquisition bulk material yard, according to three-dimensional point cloud data splicing acquisition yard overall point cloud, according to yard overall point cloud establishes elevation map;Bulk material stack height transfer car body attitude data is collected, according to body attitude data, on the basis of elevation map, planning material taking movement path, real-time update three-dimensional point cloud data and correct material taking movement path;With back-end transfer equipment communication, cooperatively controls material taking movement path, according to the three-dimensional point cloud data of real-time update dynamic calculation yard remaining material quantity, complete bulk material unmanned automatic stacking and taking transfer.The present application realizes the efficient, safe, stable operation of bucket wheel stacker-reclaimer by unmanned, intelligent control, reduces manual intervention, improves equipment operation efficiency, and is suitable for the intelligent operation and maintenance demand of large bulk material yard.

Description

Technical Field

[0001] This invention relates to the field of material handling technology, specifically to a method and system for unmanned automated stacking, retrieving and transporting of bulk materials. Background Technology

[0002] With the continuous expansion of industrial production and logistics, the use and circulation of bulk materials in industries such as mining, ports, power, and coal are becoming increasingly frequent, and the demand for stacking and reclaiming efficiency and automation in stockyards is also continuously increasing. Although traditional bucket wheel stacker-reclaimers have the advantages of continuous conveying and high capacity, their adaptability to stack height and material hardness in dynamic stockyard environments is limited, and they rely on manual operation for a long time, making it difficult to balance efficiency and safety.

[0003] To achieve intelligent and unmanned operation of bulk material storage yards, existing technologies are gradually incorporating sensor monitoring, automatic control, and 3D environmental perception to enable automatic movement, precise pitching, and adaptive cutting of the material surface. However, due to the variable material distribution in storage yards, the complexity of equipment attitude control, and the imperfect linkage and early warning systems for conveying and faults, efficiently completing core tasks such as bulk material stacking, transfer, positioning, and obstacle avoidance remains a key challenge that urgently needs to be addressed in the industry. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by this invention is: how to efficiently complete the core tasks such as automatic stacking, picking, and transfer of bulk materials.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for unmanned automatic stacking, retrieving and transferring of bulk materials, comprising:

[0007] Collect 3D point cloud data of bulk material stockpile, stitch together the 3D point cloud data to obtain the overall point cloud of the stockpile, and build an elevation map based on the overall point cloud of the stockpile.

[0008] Collect the attitude data of the bulk material stacker to loading machine body, and plan the material handling movement path based on the body attitude data and the elevation map, update the 3D point cloud data in real time, and correct the material handling movement path.

[0009] It communicates with the backend transfer equipment to coordinate the control of the material handling path, and dynamically calculates the remaining material in the stockpile based on real-time updated 3D point cloud data to complete the unmanned automatic stacking, picking and transfer of bulk materials.

[0010] As a preferred embodiment of the unmanned automatic stacking and transfer method for bulk materials described in this invention, the step of obtaining the overall point cloud of the stockyard by stitching together three-dimensional point cloud data includes filtering the three-dimensional point cloud data, performing preliminary coordinate transformation on each frame of the filtered three-dimensional point cloud data, and aligning it to the same world coordinate system.

[0011] The feature descriptors of the 3D point cloud data are calculated, and a RANSAC-based feature matching algorithm is used for coarse registration. Fine registration is then used to fine-tune the coarse registration results to accurately align overlapping areas.

[0012] Repeat the coarse registration and fine registration process to align and merge multiple frames of 3D point cloud data into the same world coordinate system to obtain the overall point cloud of the storage yard.

[0013] As a preferred embodiment of the unmanned automatic stacking and transfer method for bulk materials described in this invention, the step of establishing an elevation map based on the overall point cloud of the stockyard includes: on the basis of the overall point cloud of the stockyard, using (x, y) as the plane coordinates, setting the resolution of the grid on the plane (x, y), dividing the grid into grid units according to the resolution, recording the maximum height of each grid unit, and obtaining an equally spaced gridded elevation map.

[0014] Acquire historical data on materials transferred from bulk material yards, and set a set of key attributes for each material, including material hardness grade, bulk density, and safe slope threshold.

[0015] Based on historical data of materials, key attribute ranges for each material are obtained, and a material database is established.

[0016] When staff create a stacking, reclaiming, and transfer task, the system calls the corresponding key attributes of the material type in the material database and layers the elevation map according to the material type entered by the operator.

[0017] As a preferred embodiment of the unmanned automated stacking, retrieving, and transferring method for bulk materials described in this invention, the step of layering the elevation map includes obtaining the overall height range of the storage yard [z] based on the elevation map. min , z max Generate a baseline layer thickness based on the key properties of the material;

[0018] The slope of each grid cell is read from the elevation map. For each grid cell, the local layer thickness is calculated based on the slope and the hardness of the material, and is expressed as follows:

[0019] Δh local (i)=Δh base -α s ·f s (S(i))-α m ·f m (Hm )

[0020] Where, Δh local (i) represents the local layer thickness of mesh cell i; Δh base Indicates the reference layer thickness; α s f represents the slope correction factor; s (S(i)) represents the slope mapping function; S(i) represents the slope of grid cell i; α m f represents the hardness correction factor; m (H m ) represents the hardness mapping function; H m Indicates the hardness of material m;

[0021] By mapping slope and hardness to 0 or positive values ​​using slope mapping functions and hardness mapping functions, the relationship between Δh and hardness is quantified. base The reduction force, for the calculated Δh local (i) Perform a limiting process to obtain the actual layer thickness for each region.

[0022] As a preferred embodiment of the unmanned automated stacking and transfer method for bulk materials described in this invention, the step of planning the material handling path based on the elevation map includes obtaining the ground height H(i,j) corresponding to each grid cell (i,j) according to the elevation map, calculating the slope difference between adjacent grid cells, and marking the grid cell (i,j) as infeasible if the calculated slope difference Slope(i,j) exceeds the safe slope threshold.

[0023] The fuselage attitude data includes the fuselage orientation angle and the bucket wheel tilt angle. The motion plan of the bucket wheel machine is defined on the elevation map as: K = {(x, y, θ, φ)}, where (x, y) represents the discrete coordinates of the fuselage on the grid, θ represents the fuselage orientation angle, and φ represents the bucket wheel tilt angle.

[0024] The sampling space is constructed by the grid method. The starting position of the bulk material stack height transfer to the vehicle {(x0, y0, θ0, φ0)} is obtained according to the fuselage attitude data. The search is performed, and the neighboring nodes are expanded in turn, and the cost is accumulated until the material picking position is reached.

[0025] The output material handling path is a sequence of nodes: {(x0, y0, θ0, φ0), (x1, y1, θ1, φ1), ..., (x n y n θ n φ n )} indicates the aircraft's trajectory, orientation changes, and bucket wheel tilt angle changes.

[0026] As a preferred embodiment of the unmanned automatic stacking and transfer method for bulk materials described in this invention, the method of correcting the material handling path includes, during bucket wheel operation, acquiring three-dimensional point cloud data of the material handling position in real time through sensors, and coordinating with the real-time collected body posture data to locally update the elevation map.

[0027] Retrieve the height distribution H recorded in the previous cycle at the material sampling location on the elevation map. old (i, j), and the new height distribution H after local update new The difference between (i, j) is calculated to obtain the height difference ΔH(i, j). The material taking situation is determined based on the height difference and the actual layer thickness.

[0028] If ΔH(i, j) is greater than the actual layer thickness, it is judged as excessive material taking;

[0029] If ΔH(i,j) is less than the actual layer thickness, it is determined that the material is insufficient.

[0030] The actual layer thickness for the next cycle will be adjusted based on the material extraction situation.

[0031] As a preferred embodiment of the unmanned automatic stacking and transfer method for bulk materials described in this invention, the collaborative control includes: acquiring the transfer rate and material flow of the back-end transfer equipment, calculating the material handling rate based on the real-time collected machine posture data, and performing collaborative control based on the comparison result of the transfer rate and the material handling rate.

[0032] A bulk material unmanned automatic stacking and transfer system employing any of the methods described in this invention, wherein: a scene module collects three-dimensional point cloud data of a bulk material stockpile, stitches together the three-dimensional point cloud data to obtain an overall point cloud of the stockpile, and establishes an elevation map based on the overall point cloud of the stockpile;

[0033] The path module collects the attitude data of the bulk material stacker to loading machine body. Based on the body attitude data, it plans the material handling movement path on the elevation map, updates the 3D point cloud data in real time, and corrects the material handling movement path.

[0034] The collaboration module communicates with the backend transfer equipment to coordinate and control the material handling path. It dynamically calculates the remaining material in the stockpile based on real-time updated 3D point cloud data, thus completing the unmanned automatic stacking, picking, and transfer of bulk materials.

[0035] A computer device includes: a memory and a processor; the memory stores a computer program, including: the steps of the processor executing the computer program to implement the method described in any one of the present invention.

[0036] A computer-readable storage medium having a computer program stored thereon, comprising the steps of implementing the method described in any one of the present invention when the computer program is executed by a processor.

[0037] The beneficial effects of this invention are as follows: The method of this invention acquires three-dimensional point cloud data by arranging multiple sensors on the bucket wheel stacker-reclaimer, and plans the single cutting amount using an adaptive layering method. Combined with the linkage control with the back-end conveying equipment, it effectively improves the stability and efficiency of unattended stacker-reclaimer operations. At the same time, dynamic monitoring is used to analyze the material surface deformation and conveyor belt load information in real time, thereby automatically adjusting the pitch angle, cutting speed and transfer sequence, significantly reducing the risk of bucket wheel overload or material collapse. When foreign objects or abnormal torque are detected, the system can stop the machine in an emergency and sound an alarm, achieving safer and more continuous bulk material transportation and stockpile management. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is an overall flowchart of a method for unmanned automated stacking, retrieving and transferring of bulk materials, provided in one embodiment of the present invention.

[0040] Figure 2 A model diagram of a bucket wheel material handling component for an unmanned automated stacking, retrieving and transferring method for bulk materials, provided in one embodiment of the present invention;

[0041] Figure 3 A physical image of a bucket wheel material handling component for an unmanned automated stacking and transfer method for bulk materials, provided in one embodiment of the present invention;

[0042] Figure 4 This is a physical image of a bulk material stacking and loading vehicle, which is part of an embodiment of the present invention, for an unmanned automated stacking and transfer method for bulk materials. Detailed Implementation

[0043] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0044] Example 1, referring to Figure 1 - Figure 4As an embodiment of the present invention, a method for unmanned automated stacking, retrieving, and transferring of bulk materials is provided, comprising:

[0045] S1: Collect 3D point cloud data of bulk material stockpile, stitch together the 3D point cloud data to obtain the overall point cloud of the stockpile, and build an elevation map based on the overall point cloud of the stockpile.

[0046] Furthermore, multiple sensors, such as lidar (360° scanning or multi-beam type) and depth cameras, are installed at locations easily overlooking the bulk material stacker, such as the cantilever, tower, or roof of the bulk material yard, to acquire real-time three-dimensional point clouds of the bulk material yard. Gyroscopes, tilt sensors, and other attitude monitoring devices are also deployed at key parts of the machine. Once the stacking, reclaiming, and transfer task begins, the sensors are activated to collect three-dimensional point cloud data from multiple directions. This three-dimensional point cloud data includes point clouds on the surface of the material stack, ground reference data, and point clouds on the surface of the bulk material stacker.

[0047] Furthermore, the overall point cloud of the storage yard is obtained by stitching together the 3D point cloud data. Outlier removal and downsampling (such as based on VoxelGrid or uniform grid) are performed on each frame of local point cloud to reduce noise and reduce data volume. Based on the fuselage attitude, rotation angle and sensor calibration parameters recorded by the sensor during acquisition, a preliminary coordinate transformation is performed on each frame of point cloud to roughly align it to the same world coordinate system.

[0048] Point cloud feature descriptors (such as FPFH, ISS feature points, or other geometric features) are used to provide a feature matching basis for subsequent stitching. Coarse registration is performed on the point clouds using RANSAC-based feature matching or other matching algorithms to estimate the rotation and translation relationship between the two point clouds in 3D space by finding similar feature pairs. Fine registration refines the coarse registration results using Iterative Closest Point (ICP) or other local optimization algorithms to minimize point-to-point / point-to-surface errors and achieve more accurate alignment of overlapping areas.

[0049] Repeat the coarse registration and fine registration process to align and merge multiple frames of 3D point cloud data into the same world coordinate system to obtain the overall point cloud of the storage yard.

[0050] Furthermore, to achieve more efficient motion planning, the overall point cloud model is typically converted into a "2.5D" or "3D" discrete representation that is convenient for algorithms to use. In most bulk material yard applications, the yard mainly exhibits undulating terrain (i.e., the horizontal area is much larger than the height variation), so an elevation map is generated by extracting information from the top surface of the grid for path search.

[0051] The specific steps for establishing an elevation map based on the overall point cloud of the storage yard include: setting the grid resolution on the plane (x, y) according to the size of the storage yard and the required accuracy (e.g., 1m × 1m per grid, or finer or coarser), and calculating the entire storage yard in [x, y]. min x max ] and [y min y max Grid index within the range;

[0052] For each point (x) in the 3D point cloud i y i , z i Find the corresponding grid cell (I, J), and within that cell, count all z values ​​that fall into that grid point. i Value, take the maximum height z max (I, J) represents the height of the grid cell on the elevation map;

[0053] After calculating the maximum height of all grids, a two-dimensional matrix corresponding to the grid is obtained, thus forming an elevation map.

[0054] Using a 2.5D height map as the main input for motion planning avoids the uncertainties caused by special scenarios such as multi-layered structures or cavities. In bulk stockyards with relatively simple material yard shapes, this surface elevation projection can efficiently support the search and optimization of automatic stacking and transfer paths.

[0055] For typical bulk material handling scenarios without obvious "overhead" stockpiles (coal yards, ore yards, cement raw materials, etc.), the method of this invention can quickly model, update in real time, and automatically plan, significantly improving the efficiency and safety of stockpiling, handling, and transportation in unmanned environments. For extremely complex three-dimensional structures, a full three-dimensional voxel (VOXEL) or triangular mesh can be used; however, in the bulk material stockpiles targeted by this invention, elevation maps are sufficient for most needs, offering advantages such as higher efficiency and simpler maintenance.

[0056] Furthermore, after obtaining the elevation map, the stockyard is divided into layers according to height to guide the bucket wheel reclaimer in cutting layer by layer (or segment by segment). In existing technologies, stockyards are typically divided using "equal thickness" or "simple multi-layer settings." In reality, layer thickness, cutting priority, and bucket wheel reclaimer workload are all closely related to the material's cutability. If material characteristics can be retrieved from the database before the task begins, subsequent automatic planning will be more targeted. For example, loose materials can allow for a larger single cut depth, while hard materials require smaller layer thicknesses to prevent overload or excessive wear.

[0057] In bulk material storage environments, such as industrial or port yards, common bulk materials like coal, ore, cement raw materials, and grain often exhibit relatively predictable physical properties (hardness, density, moisture content, etc.). Establishing a material property database to pre-record frequently transported bulk material types and their corresponding hardness, loose density, or moisture content can reduce the workload of on-site ad-hoc measurements. Before initiating a stockpiling, reclaiming, or transport task, the system interface allows users to select the "material type for this operation," automatically retrieving the corresponding attributes from the database, or adjusting parameters before starting the task.

[0058] Specifically, a set of key attributes is set for each common bulk material (such as coal A, ore B, grain C, limestone D, etc.): hardness grade (such as Mohs hardness range or compressive strength indicator), bulk density, safe slope threshold, load on the feed bucket wheel, etc. The key attribute range of each material is obtained based on the historical data of the material, and a material database is established.

[0059] When staff create a stacking, reclaiming, and transfer task, the operator selects or enters the corresponding material type on the interface. Based on the material type entered by the operator, the system calls the corresponding key attributes of the material type in the material database and calculates the adaptive layer thickness to layer the elevation map.

[0060] The process of layering the elevation map includes obtaining the overall height range of the stockpile based on the elevation map, and generating a baseline layer thickness based on the key attributes of the material. The baseline layer thickness is a fixed initial value that is determined based on the overall height range of the stockpile and the characteristics of the material, either through experience or verified in previous operations (e.g., 2 meters for loose materials and 1 meter for hard materials).

[0061] The slope of each grid cell is read from the elevation map. For each grid cell, the local layer thickness is calculated based on the slope and the hardness of the material, and is expressed as follows:

[0062] Δh local (i)=Δh base -α s ·f s (S(i))-α m ·f m (H m )

[0063] Where, Δh local (i) represents the local layer thickness of mesh cell i; Δh base Indicates the reference layer thickness; α s f represents the slope correction factor; s (S(i)) represents the slope mapping function; S(i) represents the slope of grid cell i; α m f represents the hardness correction factor; m (Hm ) represents the hardness mapping function; H m This indicates the hardness of material m.

[0064] By mapping slope and hardness to 0 or positive values ​​using slope mapping functions and hardness mapping functions, the relationship between Δh and hardness is quantified. base The reduction intensity is expressed as:

[0065] f s (S(i))=max(0,S(i)-S safe )

[0066] f m (H m ) = max(0, H m -H0)

[0067] Where max represents the maximum value; S safe This indicates the safe slope threshold, which is retrieved based on the material type; H0 represents the baseline hardness.

[0068] To prevent the calculated result of the formula from being too high or too low, the calculated Δh is... local (i) Perform amplitude limiting processing, reducing Δh local (i) Limiting the minimum layer thickness Δh to which mechanical energy can effectively cut min And the layer thickness Δh to ensure that there is no risk of overload due to excessive cutting thickness in a single operation. max Between these, the actual layer thickness for each region is obtained.

[0069] It should be noted that the actual layer thickness can be understood as the vertical depth that the bucket wheel needs to excavate in one cutting operation (or one work cycle) in that area. When the system determines the actual layer thickness Δh of a certain area... local (i) after that means that on the current layer of material in that area, the bucket wheel excavator will cut off Δh this time. local The height difference is ultimately used to guide the height of the material layer that the bucket wheel excavator should cut away in each working cycle within the corresponding area, and is the core parameter for realizing the automatic layered cutting strategy of this invention.

[0070] Slope S(i) or hardness H m When α is large, s ·f s (S(i)) or α m ·f m (H m This will increase, thereby reducing the local layer thickness Δh. local (i) reduces the excavation volume of the bucket wheel excavator in one pass; when both the slope and hardness are small, the deduction term in the formula is minimal, Δh local (i) Approaching Δh base It can quickly cut layers, improving efficiency.

[0071] During automated operation, if the sensors (torque sensor or acoustic vibration sensor) detect a large difference between the actual load and the database estimate, the control system can adjust the layer thickness or lifting degree appropriately. If the material properties are found to be inconsistent with the pre-registered properties at certain times (such as a sudden increase in density or a sharp increase in moisture content), the system can record the discrepancies in real time and prompt the operator to update the material properties to gradually improve the database.

[0072] By adaptively adjusting the layer thickness, the cutting thickness is automatically reduced in areas with high slope or high hardness to prevent the bucket wheel excavator from exceeding torque limits or overturning. In flat and easy-to-dig areas, the single-layer thickness is maintained or even increased to speed up the operation. By combining the hardness values ​​of different materials in the database with feedback from on-site sensors, the thresholds and coefficients in the formula can be continuously optimized during task execution, making the system more closely match the actual bulk material conditions.

[0073] Applying this adaptive stratification approach allows for dynamic adjustments based on the local characteristics of the stockyard and the capabilities of the bucket wheel excavator, making the material handling process more efficient, stable, and safe. Compared to traditional single-thickness stratification, although it requires slightly more computation and sensor information processing, in most large-scale automated stockyard operations, the resulting efficiency and safety improvements significantly outweigh the additional computing power consumption.

[0074] In operations involving commonly used materials, directly calling database parameters allows the bucket wheel excavator to quickly enter the most suitable cutting and transport rhythm, reducing the time spent on blind trial and adjustment. For high-hardness or highly abrasive materials, pre-tightening the cutting depth or increasing the pitch safety margin can prevent excessive wear between the bucket wheel and the support plate, and also prevent overload or material collapse accidents.

[0075] S2: Collect the attitude data of the bulk material stacker to loading machine body. Based on the body attitude data, plan the material handling movement path on the elevation map, update the 3D point cloud data in real time, and correct the material handling movement path.

[0076] Furthermore, the planning of the material handling path based on the elevation map includes obtaining the ground height H(i,j) corresponding to each grid cell (i,j) according to the elevation map, calculating the slope difference between adjacent grid cells, and marking the grid cell (i,j) as infeasible if the calculated slope difference Slope(i,j) exceeds the safe slope threshold; otherwise, marking it as feasible. In addition, physical constraints such as the travel boundary and turning radius of the bulk material stacker transfer vehicle can be combined to mark grid cells that are beyond the reach of the mechanical structure as infeasible.

[0077] The motion plan of the bucket wheel excavator is defined on the elevation map as follows: K = {(x, y, θ, φ)}, where (x, y) represents the discrete coordinates of the excavator body on the grid, θ represents the orientation angle of the excavator body, and φ represents the tilt angle of the bucket wheel.

[0078] Establish the following constraint: Maximum pitch angle: φ ≤ φ max ;

[0079] Safe slope: Overly steep grids have already been removed during the feasible area assessment.

[0080] Turning radius of the machine body: On bucket wheel excavators with rotating or slewing platforms, it is necessary to ensure that there are no obstacles or collisions around the machine; this can be reflected in the expansion obstacles of the feasible grid.

[0081] Material pile height difference: This is reflected in the elevation map. If the elevation of a certain place is too high and exceeds the cutting capacity of the bucket wheel, it can also be marked as temporarily infeasible.

[0082] The sampling space is constructed using the A / D grid method. The starting position of the bulk material stack transfer to the vehicle {(x0, y0, θ0, φ0)} is obtained based on the fuselage attitude data. A search is performed, and the neighboring nodes are expanded in turn, accumulating costs until the material picking position is reached.

[0083] The output material handling path is a sequence of nodes: {(x0, y0, θ0, φ0), (x1, y1, θ1, φ1), ..., (x n y n θ n φ n )} indicates the aircraft's trajectory, orientation changes, and bucket wheel tilt angle changes.

[0084] like Figure 4 As shown, the bulk material stacker-to-load vehicle body moves on tracks according to the planned discrete path (x n y n θ n φ n It sends walking commands (how many meters forward / backward) and turning commands (how many degrees the fuselage turns left / right) to the walking drive system segment by segment to achieve overall attitude adjustment of the fuselage.

[0085] like Figure 3 As shown, the bucket wheel assembly is fixed to the front end of the cantilever and can be adjusted up and down and left and right within a certain range via the pitch cylinder and slewing mechanism. Once the fuselage reference point (x) is reached... n y n θ n φ n Once the geometric relationship is determined, the position of the bucket wheel can be calculated. Since the mechanical structure of the fuselage and the bucket wheel remains unchanged, after completing the first calculation of the relative geometric relationship, the position of the bucket wheel can be directly obtained from the position of the fuselage without needing to be calculated again.

[0086] It should be noted that in the elevation map, the bulk material stacker transfer vehicle occupies a large portion of the space. The discrete coordinates (x, y) of the vehicle body on the grid are the "motion reference" of the whole machine. The planar motion of the vehicle body (including walking and turning) can be described by its translation and orientation changes. A reference point is selected at the main turning center of the bulk material stacker transfer vehicle (such as the turntable center or the geometric center of the vehicle body), and the reference point is defined as the discrete coordinates (x, y) of the vehicle body on the grid.

[0087] Furthermore, when performing the bucket wheel material handling operation, the bucket wheel tilt angle φ is calculated based on the actual layer thickness to control the material handling. The core idea is to use the actual layer thickness to estimate the amount of extension and retraction that the pitching cylinder should extend, thereby obtaining the required bucket wheel tilt angle.

[0088] Specifically, the hinge point between the cantilever and the main structure of the machine is considered the pitch rotation center. The difference between the current height of the pitch rotation center and the material layer surface is calculated, and then combined with the actual layer thickness to determine the expected descent of the bucket wheel center. Based on the inverse kinematics of a single-joint arm in existing mechanics and robotics, the required descent is mapped to the required pitch angle φ. n The control system will φ n The command is sent to the pitch cylinder or motor drive module, instructing the actuator to drive the boom to move down (or up) to that angle. In actual machinery, closed-loop control (such as PID or feedback based on cylinder position / tilt sensors) is often used to continuously correct the output until φ... n It matches and remains stable within the error range.

[0089] Before the bulk material stacker reaches the designated picking position, the rotational speed or feed rate of the bucket wheel within that thickness range needs to be determined. Specifically, the system first reads the maximum available rotational speed of the bucket wheel and the allowable pitch range of the equipment, and combines this with the material properties, hardness, and layer thickness in the material yard; a target picking rate q (tons / hour) is set to ensure that "single layer cutting volume × rotational speed" is neither overloaded nor too conservative, and the corresponding bucket wheel rotational speed is calculated. If the machine body forward speed also needs to be considered, the volumetric flow rate can be approximated by cross-sectional area × forward speed, and then the bucket wheel rotational speed can be matched. The target picking rate q can be set with a preset value for the material type and stored as a key attribute in the material database.

[0090] Furthermore, the correction of the material handling path includes automatically defining a region of interest (ROI) based on the bucket wheel radius, rotation range, and current cutting layer height during bucket wheel operation. For example, the radius of the circle can be slightly larger than the distance from the outer edge of the bucket wheel, with the center of the bucket wheel as the center, or the fan-shaped area in front can be scanned in a focused manner to reduce the amount of data processing in irrelevant areas and improve real-time performance. The three-dimensional point cloud data of the ROI can be acquired in real time through sensors and combined with the real-time collected body attitude data to locally update the elevation map.

[0091] Retrieve the height distribution H recorded in the previous cycle at the material sampling location on the elevation map. old (i, j), and the new height distribution H after local update new The difference between (i, j) is calculated to obtain the height difference ΔH(i, j). The material taking situation is determined based on the height difference and the actual layer thickness.

[0092] Excessive material extraction: If ΔH(i,j) is greater than the expected material extraction thickness (e.g., much greater than the actual layer thickness), it may indicate material collapse or local over-digging.

[0093] Insufficient material intake: If ΔH(i,j) is much smaller than expected, it indicates that the material level is still too high, and the bucket wheel may not have penetrated to a sufficient depth.

[0094] Abnormal protrusion: If H is detected new If (i, j) is higher than the expected actual layer thickness, or if foreign objects (hardness greater than the set value) are present, it may indicate the presence of solid obstacles or material accumulation.

[0095] Based on the layer cutting thickness and the allowable fluctuation range of the material surface, the upper limit and lower limit of deformation are defined.

[0096] If ΔH(i,j) exceeds the deformation limit, it is judged as a "collapse or over-excavation" situation, and the pitch actuator is ordered to raise the bucket wheel or slow down.

[0097] If ΔH(i,j) is lower than the lower limit of deformation, it is determined that "insufficient material is taken out", and the pitch actuator is ordered to move the bucket wheel down by a certain angle or distance.

[0098] If an abnormal protrusion appears, mark it as "needs obstacle avoidance or replanning".

[0099] S3: Communicates with the backend transfer equipment to coordinate the control of the material handling path, dynamically calculates the remaining material quantity in the stockpile based on real-time updated 3D point cloud data, and completes unmanned automatic stacking, picking and transfer of bulk materials.

[0100] Furthermore, the collaborative control includes acquiring the transfer rate and material flow rate of the back-end transfer equipment, calculating the material handling rate based on the real-time collected machine posture data, and performing collaborative control based on the comparison result of the transfer rate and the material handling rate.

[0101] like Figure 2 As shown, a conveyor belt is connected to the rear of the bucket wheel for transporting materials. The rear-end transfer equipment includes the conveyor belt and other subsequent material transfer equipment. A two-way data communication is established between the bucket wheel machine control system and the rear-end transfer equipment via industrial Ethernet, wireless network or fieldbus (such as PROFIBUS / Modbus). This interface receives the belt speed information and load status of the rear conveyor belt, and can also send the current material picking speed and estimated material flow rate of the bucket wheel machine to the other party.

[0102] Real-time acquisition of conveyor belt speed v belt The current belt speed is fed back by sensors or frequency converters in the back-end equipment;

[0103] Surface height or material flow rate l belt The conveyor belt is equipped with a material level sensor or belt scale to detect whether the belt height exceeds the set threshold.

[0104] Bucket wheel material handling rate q new It can be estimated from the bucket wheel speed and the estimated single cutting amount / layer thickness.

[0105] The coordinated control includes, but is not limited to, belt speed-reclaim rate matching, belt surface height monitoring, and abnormal load protection. Specifically, the belt speed-reclaim rate matching includes adjusting the initially planned reclaim rate q of the bucket wheel excavator... new After calculation, it is compared with the current belt speed v. belt For comparison:

[0106] If q new >βv belt If the feed rate of the bucket wheel is faster than the safe transport capacity of the conveyor belt, a deceleration command or a reduction in the material picking depth is sent to the bucket wheel control.

[0107] If q new >γl belt This indicates that there is still room for speed increase at the rear end, and the bucket wheel speed can be appropriately increased to improve efficiency.

[0108] Among them, β and γ are adjustable coefficients, which ensure that the belt load is maintained within a safe range while maximizing the use of conveying capacity.

[0109] The band height monitoring includes monitoring the band height when the backend detects a band height of l. belt If the preset safety threshold is exceeded, the system will automatically send an alarm and control request: the bucket wheel excavator control system will immediately reduce the bucket wheel speed or suspend the digging action until the face is restored to a reasonable range; if no improvement is seen after a period of time, it will prompt remote monitoring or central control personnel to intervene manually.

[0110] The abnormal load protection includes the following: if the conveyor malfunctions (overload shutdown or deceleration), the information is transmitted to the bucket wheel excavator with high priority in the communication interface: upon receiving the information, the bucket wheel excavator immediately stops (or slows down) the material-taking rotation to ensure that the material does not accumulate at the conveyor end, causing blockage or spillage.

[0111] Through coordinated control of the bucket wheel excavator and the downstream transfer equipment, intelligent linkage of the entire automated stacking, reclaiming, and transfer system is achieved, improving the continuity and stability of bulk material conveying. Through two-way data communication, the bucket wheel excavator can obtain real-time information on the conveyor belt speed, belt height, and load, and match this information with its own material reclaiming rate. This dynamically coordinates the material reclaiming rate with the downstream conveying capacity, preventing overloading of the conveyor belt due to excessive feeding or inefficient operation of the conveying system due to insufficient feeding.

[0112] Furthermore, the dynamic calculation of the remaining material quantity in the stockpile based on real-time updated 3D point cloud data includes installing belt scales or flow sensors inside the machinery or on the conveyor belt at the end of the cantilever to measure the instantaneous material conveying volume, and calculating the total transfer volume over a time period Δt by integration:

[0113]

[0114] Where P represents the total transfer volume; t0 represents the start time; and p(t) represents the instantaneous transfer volume.

[0115] In the elevation map, the initial volume and current remaining volume of this layer in the stockpile can be estimated; the difference between the two should roughly match P (within the error threshold). If the difference is too large, it indicates that the model does not match reality (there may be material overflow into other areas or inaccurate material density estimation in the database), and it can be corrected when the material database or elevation map is updated.

[0116] When the system detects that the remaining material in a layer or region is below a threshold (e.g., <5% remaining material), it considers that the area to be basically empty. The system will then issue a "next region or lower layer" instruction, allowing the bucket wheel excavator to move to the adjacent layer or the next high point region according to the predetermined layering order, until the material removal task of all regions is completed, and then send a task completion signal.

[0117] The system utilizes level sensors and belt scales to detect the load status of the conveyor belt, ensuring that the belt height remains within a safe range. If the threshold is exceeded, the system automatically reduces the bucket wheel excavator's material handling rate or suspends operation to prevent material spillage or blockage. Furthermore, if the conveyor belt malfunctions due to overload, fault, or emergency shutdown, this information is quickly transmitted to the bucket wheel excavator control system via an industrial communication interface, ensuring the excavator immediately adjusts its operating status. This reduces operational interruptions caused by conveyor system failures and improves system stability.

[0118] Example 2, refer to Figure 2 -and Figure 3 This is one embodiment of the present invention. In order to verify the beneficial effects of the present invention, a simulation experiment is conducted for scientific demonstration.

[0119] like Figure 2 and Figure 3The diagram shown is a model of the bucket wheel material handling assembly of the present invention, including the material handling bucket wheel, conveyor belt and related structures.

[0120] The bucket wheel is the core material-handling component of the equipment. It is surrounded by multiple buckets, each with a first radial opening and a second opening in the direction of rotation, used to grab bulk materials during rotation. The claws on the outer edge of the buckets are used to cut and grab the stockpile, allowing the material to enter the bucket and be carried to the top discharge position as it rotates.

[0121] A conveyor belt is connected to the rear of the bucket wheel to receive the material unloaded from the bucket wheel and transport it to subsequent transfer equipment. The material on the bucket wheel falls evenly onto the conveyor belt through a guiding component, ensuring that the material does not scatter or clog during transportation.

[0122] The bucket wheel's rotation speed, material extraction depth, and pitch angle can be dynamically adjusted based on a real-time updated elevation map. The system first calculates the remaining material quantity and current layer thickness in the stockpile, and then automatically calculates the required pitch angle based on the geometric relationship between the bucket wheel and the machine body, ensuring the bucket wheel accurately cuts into the target material layer. During operation, sensors continuously monitor changes in the material surface. If material collapse, insufficient cutting, or over-digging is detected, the system will automatically adjust the bucket wheel's tilt angle, rotation speed, or feed rate to ensure operational stability and reduce equipment wear and energy consumption.

[0123] Furthermore, the bucket wheel excavator is linked with the downstream conveyor system for control. It receives data such as conveyor belt speed, load status, and material level height via an industrial communication interface, and feeds back its own material handling rate to the conveyor system to ensure that the material handling speed matches the conveying capacity. When the conveyor belt height exceeds a safety threshold, the system automatically adjusts the bucket wheel speed or suspends operation to prevent overloading or material spillage. If the conveyor malfunctions or stops in an emergency, the bucket wheel will also stop material handling synchronously, ensuring a safe and stable conveying process. Overall, the bucket wheel material handling component of this invention, through intelligent control, precise material handling, dynamic adjustment, and conveying linkage, achieves efficient, stable, and unmanned stacking, handling, and transfer of bulk materials, making it suitable for the high-efficiency operation requirements of large-scale automated material yards.

[0124] If the above functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0125] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0126] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0127] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0128] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for unmanned automated stacking, retrieving, and transferring of bulk materials, characterized in that, include: Collect 3D point cloud data of bulk material stockpile, stitch together the 3D point cloud data to obtain the overall point cloud of the stockpile, and build an elevation map based on the overall point cloud of the stockpile. Collect the attitude data of the bulk material stacker to loading machine body, and plan the material handling movement path based on the body attitude data and the elevation map, update the 3D point cloud data in real time, and correct the material handling movement path. It communicates with the back-end transfer equipment to coordinate the control of the material picking movement path, and dynamically calculates the remaining material in the stockpile based on the real-time updated 3D point cloud data to complete the unmanned automatic stacking, picking and transfer of bulk materials. The layering of the elevation map includes obtaining the overall height range of the storage yard based on the elevation map. Generate a baseline layer thickness based on the key properties of the material; The slope of each grid cell is read from the elevation map. For each grid cell, the local layer thickness is calculated based on the slope and the hardness of the material, and is expressed as follows: ； in, Represents grid cells Local layer thickness; Indicates the reference layer thickness; Indicates the slope correction factor; Represents the slope mapping function; Represents grid cells The slope; This indicates the hardness correction factor; Represents the hardness mapping function; Indicates material The hardness; By mapping slope and hardness to 0 or positive values ​​using slope mapping functions and hardness mapping functions, the relationship between slope and hardness is quantified. The reduction intensity, for the calculated Perform amplitude limiting to obtain the actual layer thickness for each region.

2. The unmanned automated stacking, retrieving, and transferring method for bulk materials as described in claim 1, characterized in that: The step of obtaining the overall point cloud of the storage yard by stitching together three-dimensional point cloud data includes filtering the three-dimensional point cloud data, performing preliminary coordinate transformation on each frame of three-dimensional point cloud data after filtering, and aligning it to the same world coordinate system. The feature descriptors of the 3D point cloud data are calculated, and a RANSAC-based feature matching algorithm is used for coarse registration. Fine registration is then used to fine-tune the coarse registration results to accurately align overlapping areas. Repeat the coarse registration and fine registration process to align and merge multiple frames of 3D point cloud data into the same world coordinate system to obtain the overall point cloud of the storage yard.

3. The unmanned automated stacking, retrieving, and transferring method for bulk materials as described in claim 2, characterized in that: The process of creating an elevation map based on the overall point cloud of the storage yard includes, on the basis of the overall point cloud of the storage yard, using... For planar coordinates, set the grid on the plane. Based on the resolution, the map is divided into grid cells, and the maximum height of each grid cell is recorded to obtain an equally spaced gridded elevation map. Acquire historical data on materials transferred from bulk material yards, and set a set of key attributes for each material, including material hardness grade, bulk density, and safe slope threshold. Based on historical data of materials, key attribute ranges for each material are obtained, and a material database is established. When staff create a stacking, reclaiming, and transfer task, the system retrieves the corresponding material type and key attributes from the material database based on the material type entered by the operator, and then layers the elevation map.

4. The unmanned automated stacking, retrieving, and transferring method for bulk materials as described in claim 3, characterized in that: The process of planning the material handling path based on the elevation map includes obtaining each grid cell from the elevation map. Corresponding ground height Calculate the slope difference between adjacent grid cells. If the calculated slope difference... If the slope exceeds the safe slope threshold, the grid cells will be... Mark as infeasible; The fuselage attitude data includes the fuselage orientation angle and the bucket wheel tilt angle, and the motion plan of the bucket wheel excavator is defined on the elevation map: ,in This represents the discrete coordinates of the fuselage on the grid. Indicates the angle of the fuselage; Indicates the angle of inclination of the bucket wheel; The sampling space was constructed using a grid method, and the starting position of the bulk material stack height for loading was obtained based on the fuselage attitude data. Perform a search, expand the neighboring nodes in turn, accumulate costs, until the material picking location is reached; The output material handling path is a sequence of nodes. This indicates the aircraft's trajectory, orientation changes, and bucket wheel tilt angle changes.

5. The unmanned automated stacking, retrieving, and transferring method for bulk materials as described in claim 4, characterized in that: The correction of the material picking movement path includes, during bucket wheel operation, acquiring three-dimensional point cloud data of the material picking position in real time through sensors, and combining it with the real-time collected body attitude data to locally update the elevation map; Retrieve the height distribution of the material sampling location recorded in the previous cycle from the elevation map. , and the new height distribution after local update Perform difference calculations to obtain the height difference. The material selection is determined based on the height difference and the actual layer thickness: like If the thickness exceeds the actual layer thickness, it is determined to be excessive material extraction. like If the thickness is less than the actual layer thickness, it is determined to be insufficient material. The actual layer thickness for the next cycle will be adjusted based on the material extraction situation.

6. The unmanned automated stacking, retrieving, and transferring method for bulk materials as described in claim 5, characterized in that: The collaborative control includes acquiring the transfer rate and material flow of the back-end transfer equipment, calculating the material handling rate based on the real-time collected machine posture data, and executing collaborative control based on the comparison result of the transfer rate and the material handling rate.

7. A bulk material unmanned automated stacking and transfer system, applied to the bulk material unmanned automated stacking and transfer method according to any one of claims 1 to 6, characterized in that, include, The scene module collects 3D point cloud data of bulk material stockpiles, stitches together the 3D point cloud data to obtain the overall point cloud of the stockpiles, and builds an elevation map based on the overall point cloud of the stockpiles. The path module collects the attitude data of the bulk material stacker to loading machine body. Based on the body attitude data, it plans the material handling movement path on the elevation map, updates the 3D point cloud data in real time, and corrects the material handling movement path. The collaboration module communicates with the backend transfer equipment to coordinate and control the material handling path. It dynamically calculates the remaining material in the stockpile based on real-time updated 3D point cloud data, thus completing the unmanned automatic stacking, picking, and transfer of bulk materials.

8. A computer device, comprising: Memory and processor; The memory stores a computer program, characterized in that: when the processor executes the computer program, it implements the steps of the unmanned automatic stacking and transfer method for bulk materials as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the unmanned automated stacking, retrieving and transferring method for bulk materials as described in any one of claims 1-6.

Images