A bucket wheel machine unmanned cooperative operation material taking path planning method

Abstract

The present application relates to the technical field of path planning, in particular to a kind of bucket wheel machine unmanned cooperative operation's material taking path planning method, comprising the following steps: the three-dimensional stockpile model of stockyard is constructed, according to the operation position and operation range of adjacent bucket wheel machine, the operation overlap area of adjacent bucket wheel machine is determined;The stockpile in operation overlap area is divided into several stockpile blocks, and the priority distribution table of the stockpile block in overlap area is generated by priority calculation;Based on priority distribution table, the stockpile block of operation overlap area is assigned to adjacent two bucket wheel machines;The preliminary path of each bucket wheel machine is planned using the allocation result, and the path planning needs to follow;Real-time stockpile form updates and path adjustment.The present application effectively avoids the conflict of two bucket wheel machines processing the same stockpile block, while achieving dynamic balance of task load, ensuring the efficiency and sustainability of cooperative operation.

Description

Technical Field

[0001] This invention relates to the field of path planning technology, and in particular to a method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator. Background Technology

[0002] Bucket wheel excavators, as large-scale stacker-reclaimer equipment, are widely used in bulk material transportation and storage fields such as ports, mines, and power plants. Their main task is to efficiently complete material stacking and reclaiming operations. However, with the expansion of bulk material yards and the increasing complexity of operational needs, the traditional operating methods of bucket wheel excavators have gradually revealed the following problems:

[0003] Frequent conflicts in collaborative operations: In scenarios where multiple bucket wheel excavators work together, the working areas of adjacent bucket wheel excavators may overlap. If there is a lack of reasonable task allocation and path planning mechanisms, multiple devices may process the same pile of material at the same time, thereby causing operational conflicts and waste of equipment resources.

[0004] Insufficient adaptability to dynamic environments: The stockpile shape of bulk material yards often changes due to material reclaiming, collapse or landslides. Traditional static path planning methods are difficult to adapt to these dynamic changes in a timely manner, resulting in path planning failure or reduced operational efficiency, and may even cause equipment safety problems.

[0005] To address the above issues, current research mainly focuses on data sensing based on a single sensor or path planning in static environments, lacking comprehensive solutions for dynamic material stacking environments and multi-machine collaborative operation scenarios. Summary of the Invention

[0006] This invention provides a method for planning the material handling path in unmanned collaborative operation of bucket wheel excavators.

[0007] A method for planning the material handling path in unmanned collaborative operation of a bucket wheel excavator includes the following steps:

[0008] S1. Real-time data of the material yard area is collected by multimodal sensors to construct a three-dimensional stockpile model of the material yard. Based on the working position and working range of adjacent bucket wheel excavators, the overlapping area of ​​adjacent bucket wheel excavators is determined and marked in the three-dimensional stockpile model.

[0009] S2, divide the stockpile in the overlapping area of ​​the operation into several stockpile blocks, and generate a priority distribution table of the stockpile blocks in the overlapping area by calculating the priority and taking into account the stockpile height and stockpile stability.

[0010] S3, based on the priority distribution table, allocates the stack blocks in the overlapping operation area to two adjacent bucket wheel excavators. The allocation rules include:

[0011] S31, high-priority stockpiles are preferentially allocated to bucket wheel excavators that are closest to them;

[0012] S32, avoids the same pile of material being assigned to two bucket wheel excavators, ensuring the independence of task allocation;

[0013] S33, maintain the balance of material distribution to avoid idle or overloaded operation of a bucket wheel excavator;

[0014] S4, using the allocation results of S3, plans a preliminary path for each bucket wheel excavator. The path planning must follow:

[0015] S41, the path of each bucket wheel excavator is limited to the area of ​​its assigned stockpile block;

[0016] S42, path nodes are arranged in descending order of priority to ensure that material picking tasks are completed according to priority;

[0017] S43, the path planning takes into account the boom length and rotation range of the bucket wheel excavator to avoid entering unassigned areas;

[0018] S5, Real-time Material Stacking Pattern Update and Path Adjustment: During the operation of the bucket wheel excavator, when the position of the material stack block in the overlapping area changes, the distance between the material stack block and the bucket wheel excavator is recalculated and reassigned to the nearest bucket wheel excavator with the updated distance. When the material stacking height or material stacking stability changes, the priority of the material stack block is updated.

[0019] Optionally, S1 specifically includes:

[0020] S11 is equipped with a lidar and camera installed on the bucket wheel excavator to collect real-time data of the material yard area, including the height, density distribution and boundary shape of the material pile, and to perform fusion processing on the collected real-time data;

[0021] S12, based on the calibrated data, a three-dimensional point cloud model of the material yard area is generated by point cloud processing. Based on the three-dimensional point cloud model, a three-dimensional stockpile model of the material yard is constructed through surface fitting and volume calculation to obtain the spatial distribution, stockpile height and volume information of the stockpile.

[0022] S13. Based on the operating parameters of the bucket wheel excavator, including boom length, rotation radius and actual working position, calculate the operating coverage of each bucket wheel excavator, and use geometric calculation methods to analyze the overlapping part of the operating range of two adjacent bucket wheel excavators to determine the boundary coordinates of the overlapping area.

[0023] S14. In the three-dimensional material stacking model, spatially label the determined overlapping areas of operations.

[0024] Optionally, S2 specifically includes:

[0025] S21, Block Division: Based on the 3D stacking model of the overlapping area, the overlapping area is divided into several unit stacking blocks according to a fixed spatial grid size (Δx, Δy). The 3D center coordinates of each stacking block are (x...). k y k , z k ), where z k This indicates the average height of the stockpile;

[0026] S22, Priority Calculation Parameter Extraction: For each stockpile k, extract the following feature parameters:

[0027] a) Stacking height H k The average height of the stockpile is calculated using the following formula: Where, N k z represents the number of point cloud data points within the stockpile. i The height of a point within the stockpile;

[0028] b) Stockpile stability S k The stability coefficient based on the slope of the stockpile is defined as follows:

[0029] Where, θ k Let θ be the slope angle of the stockpile block k. max The maximum allowable stable slope angle for the stockpile. The ratio of the height difference within the stockpile to the horizontal distance is tan(θ). max The value is defined as the tangent value corresponding to the maximum stable slope of the stockpile.

[0030] S23, Priority Calculation: Calculate the priority P of each stockpile block by considering both stockpile height and stockpile stability. k :P k =ω1·H k +ω2·S k Where ω1 and ω2 are weight parameters for priority calculation, reflecting the importance of stockpile height and stockpile stability respectively, satisfying ω1+ω2=1, ω1 is 0.6 and ω2 is 0.4;

[0031] S24, Generation of the priority distribution table: Based on the priority P of each stockpile. k The stacked blocks within the overlapping area are sorted to generate a priority distribution table, which includes the planar coordinates (x, y) of the stacked blocks. k y k Priority value P k Stacking height H k Stockpile stability S k This information is used to guide subsequent allocation of stockpiles and path planning.

[0032] Optionally, in S31, the high-priority stockpile blocks are preferentially allocated to the nearest bucket wheel excavators, which includes calculating the distance D between the stockpile block k and the two adjacent bucket wheel excavators. 1k and D 2k According to the priority value P of each stockpile in the priority distribution table k and planar coordinates (x) k y k The calculation is as follows:

[0033] Where (X1, Y1) and (X2, Y2) are the current positions of bucket wheel excavator 1 and bucket wheel excavator 2, respectively. Priority is given to allocating the highest priority stack block k to the nearest bucket wheel excavator i, i.e., the bucket wheel excavator that meets the following conditions:

[0034] i = arg min i∈{1，2} D ik .

[0035] Optionally, the avoidance of allocating the same pile of material to two bucket wheel excavators in S32 is implemented based on the task allocation independence rule, ensuring that the same pile of material k will not be allocated to two bucket wheel excavators at the same time. Before allocation, it is checked whether the pile of material k has been allocated. If k has been allocated to bucket wheel excavator i, it is prohibited from being allocated to another bucket wheel excavator, thus ensuring the independence of task allocation.

[0036] Optionally, the avoidance of idle or overloaded operation of a bucket wheel excavator in S33 is implemented based on load balancing rules. By monitoring the task progress and the number of allocated material blocks of the two bucket wheel excavators in real time, the task load is balanced, and the number of material blocks N1 and N2 currently allocated to bucket wheel excavators 1 and 2 are calculated. During the allocation process, when the load of one bucket wheel excavator is significantly higher than that of the other (i.e., N1-N2>ΔN), the load is balanced. max ΔN max If the value is 2), the remaining stockpiles will be allocated to the bucket wheel excavators with lighter loads.

[0037] Optionally, in step S4, the planar coordinates (x, y) of each stockpile block are extracted based on the stockpile blocks allocated in step S3. k y k As path nodes, the set of path nodes assigned to each bucket wheel excavator is sorted according to priority value P. k Sort the nodes from highest to lowest to generate a path node queue. Where i represents the bucket wheel machine number.

[0038] Optionally, in S42, arranging path nodes in descending order of priority includes arranging them according to priority queue Q. i Connect the path nodes in sequence to plan the path.

[0039] Prioritize the retrieval of high-priority stockpiles.

[0040] Optionally, S5 specifically includes:

[0041] S51, Recalculation and Reassignment When the Position of a Stockpile Changes: When the position of a stockpile changes (e.g., due to collapse or landslide, i.e., the plane coordinates change from (x...)... k y k ) becomes the new planar coordinates (x) k ′,y k When the distance D between the stockpile and the bucket wheel excavator is recalculated, the distance D between the stockpile and the bucket wheel excavator is recalculated. ik ′, and assign it to the bucket wheel machine that is closest to it after the update;

[0042] S52, Reassignment: Based on the updated distance, assign the stockpile block k to the bucket wheel excavator i that satisfies the following condition: i = argmin i∈{1，2} D ik ′.

[0043] Optionally, S5 further includes:

[0044] Stockpile Height Update: Recalculate the average height H of the stockpile block k ′;

[0045] Stockpile stability update: Based on the updated state of the stockpile, recalculate its stability S. k ′;

[0046] Priority update: Recalculate the priority P of the stockpile. k ′.

[0047] The beneficial effects of this invention are:

[0048] This invention, by constructing a three-dimensional stockpile model of the material yard and combining it with multi-modal sensors to monitor changes in the stockpile shape in real time, can accurately identify the overlapping areas of adjacent bucket wheel excavators and dynamically allocate stockpile blocks. It uses a priority distribution table to guide the task allocation and path planning of stockpile blocks, effectively avoiding conflicts between two bucket wheel excavators handling the same stockpile block, while achieving dynamic balance of task load, ensuring the efficiency and continuity of collaborative operation.

[0049] This invention addresses the morphological changes in stockpiles caused by collapses, landslides, etc., by designing a dynamic update mechanism. By recalculating the distance between the stockpile blocks and the bucket wheel excavator and the stockpiling priority in real time, it ensures that the stockpile blocks are always assigned to the nearest bucket wheel excavator. Furthermore, it adjusts the priority distribution table based on the latest stockpile height and stability, optimizes path planning, and enhances the system's adaptability to dynamic environments, providing strong technical support for unmanned collaborative operations under complex working conditions.

[0050] This invention utilizes dynamically allocated material stack information to strictly limit the planned bucket wheel excavator path within its assigned range, avoiding path intersections or resource waste. This ensures the priority execution of high-priority tasks and optimizes the overall path, minimizing the risk of path conflicts and improving the operating efficiency and safety of the bucket wheel excavator. Furthermore, by incorporating constraints related to the boom length and rotation range of the bucket wheel excavator, the accuracy of path planning is further enhanced, effectively improving the stability and safety of unmanned operations. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram illustrating the division and priority calculation of stockpiles in an embodiment of the present invention. Detailed Implementation

[0054] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0055] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0056] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0057] like Figures 1-2 As shown, a method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator includes the following steps:

[0058] S1. Real-time data of the material yard area is collected by multimodal sensors to construct a three-dimensional stockpile model of the material yard. Based on the working position and working range of adjacent bucket wheel excavators, the overlapping area of ​​adjacent bucket wheel excavators is determined and marked in the three-dimensional stockpile model.

[0059] S2, divide the stockpile in the overlapping area of ​​the operation into several stockpile blocks, and generate a priority distribution table of the stockpile blocks in the overlapping area by calculating the priority and taking into account the stockpile height and stockpile stability.

[0060] S3, based on the priority distribution table, allocates the stack blocks in the overlapping operation area to two adjacent bucket wheel excavators. The allocation rules include:

[0061] S31, high-priority stockpiles are preferentially allocated to bucket wheel excavators that are closest to them;

[0062] S32, avoids the same pile of material being assigned to two bucket wheel excavators, ensuring the independence of task allocation;

[0063] S33, maintain the balance of material distribution to avoid idle or overloaded operation of a bucket wheel excavator;

[0064] S4, using the allocation results of S3, plans a preliminary path for each bucket wheel excavator. The path planning must follow:

[0065] S41, the path of each bucket wheel excavator is limited to the area of ​​its assigned stockpile block;

[0066] S42, path nodes are arranged in descending order of priority to ensure that material picking tasks are completed according to priority;

[0067] S43, the path planning takes into account the boom length and rotation range of the bucket wheel excavator to avoid entering unassigned areas;

[0068] S5, Real-time Material Stacking Pattern Update and Path Adjustment: During the operation of the bucket wheel excavator, the position of the initially divided material stack may change due to material collapse, landslides, etc. When the position of the material stack changes in the overlapping area of ​​the operation, the distance between the material stack and the bucket wheel excavator is recalculated and reassigned to the nearest bucket wheel excavator after the update. When the material stack height and material stack stability change, the priority of the material stack is updated.

[0069] S1 specifically includes:

[0070] S11 is equipped with a lidar and camera installed on the bucket wheel excavator to collect real-time data of the material yard area, including the height, density distribution and boundary shape of the material pile, and to perform fusion processing on the collected real-time data;

[0071] S12, based on the calibrated data, a three-dimensional point cloud model of the material yard area is generated by point cloud processing. Based on the three-dimensional point cloud model, a three-dimensional stockpile model of the material yard is constructed through surface fitting and volume calculation to obtain the spatial distribution, stockpile height and volume information of the stockpile.

[0072] S13. Based on the operating parameters of the bucket wheel excavator, including boom length, rotation radius and actual working position, calculate the operating coverage of each bucket wheel excavator, and use geometric calculation methods to analyze the overlapping part of the operating range of two adjacent bucket wheel excavators to determine the boundary coordinates of the overlapping area.

[0073] S14. In the three-dimensional material stacking model, spatially label the determined overlapping areas of operations.

[0074] LiDAR and camera data fusion:

[0075] P(x, y, z) = α·P LiDAR (x, y, z) + β·P Camera (x, y, z), where P(x, y, z) is the fused 3D point cloud data, (x, y, z) represents the 3D coordinates of the point, and P... LiDAR (x, y, z) is the 3D point cloud data acquired by the lidar, P Camera (x, y, z) is the 3D point cloud data acquired by the camera, and α and β are weighting coefficients that reflect the importance of the LiDAR and camera data. They are usually set according to the accuracy of the sensors (α = 0.7, β = 0.3).

[0076] The mathematical expression of the three-dimensional stockpile model is as follows: in,

[0077] Z = f(x, y) is the surface model of the stockpile in the material yard, representing the stockpile height at any point (x, y). Interp(·) is the interpolation function used to convert point cloud data into a continuous surface model.

[0078] This represents the coordinates of the i-th point in the collected point cloud dataset;

[0079] Material stockpile volume calculation: Where V is the volume of the stockpile. Z is the projected area of ​​the stockpile on the horizontal plane, f(x, y) is the surface model of the stockpile, and Z is the projection area of ​​the stockpile on the horizontal plane. ground It is the ground reference height;

[0080] Calculation of the operating range of adjacent bucket wheel excavators: Among them, R i (x, y) is the working radius of bucket wheel excavator i, (X... i Y i ) is the coordinate of bucket wheel machine i, R max，i R is the maximum operating radius of bucket wheel excavator i; condition: if R i (x, y) ≤ R max，i If point (x, y) is within the operating range of bucket wheel machine i;

[0081] The boundary of the overlapping region is then calculated as follows:

[0082] in, R1(x, y) and R2(x, y) represent the overlapping working areas of two adjacent bucket wheel excavators, respectively, and represent the working radii of bucket wheel excavator 1 and bucket wheel excavator 2.

[0083] The labeling rules for overlapping areas of tasks are as follows:

[0084] Where M(x, y, z) is the label matrix, indicating whether a point in the 3D material stacking model belongs to an overlapping region. The overlapping area is the work area. (x, y, z) are the coordinates of a point in the 3D stacking model. Points with a value of 1 belong to the overlapping area and can be marked as conflict areas in the 3D model for subsequent path planning.

[0085] S2 specifically includes:

[0086] S21, Block Division: Based on the 3D stacking model of the overlapping area, the overlapping area is divided into several unit stacking blocks according to a fixed spatial grid size (Δx, Δy). The 3D center coordinates of each stacking block are (x...). k y k , z k ), where z k This represents the average height of the stockpile, assuming the height difference between adjacent stockpiles is less than a preset threshold. h The grid cells form a more uniform material stack area;

[0087] S22, Priority Calculation Parameter Extraction: For each stockpile k, extract the following feature parameters:

[0088] a) Stacking height H k The average height of the stockpile is calculated using the following formula: Where, N k z represents the number of point cloud data points within the stockpile. i The height of a point within the stockpile;

[0089] b) Stockpile stability Sk The stability coefficient based on the slope of the stockpile is defined as follows:

[0090] Where, θ k Let θ be the slope angle of the stockpile block k. max The maximum allowable stable slope angle for the stockpile. The ratio of the height difference within the stockpile to the horizontal distance is tan(θ). max ) is defined as the tangent value corresponding to the maximum stable slope of the stockpile. For bulk materials, tan(θ) max The value is between 0.5 (approximately 26.6°) and 1.0 (approximately 45°).

[0091] S23, Priority Calculation: Calculate the priority P of each stockpile block by considering both stockpile height and stockpile stability. k :P k =ω1·H k +ω2·S k Where ω1 and ω2 are weight parameters for priority calculation, reflecting the importance of stockpile height and stockpile stability respectively, satisfying ω1+ω2=1, ω1 is 0.6 and ω2 is 0.4;

[0092] S24, Generation of the priority distribution table: Based on the priority P of each stockpile. k The stacked blocks within the overlapping area are sorted to generate a priority distribution table, which includes the planar coordinates (x, y) of the stacked blocks. k y k Priority value P k Stacking height H k Stockpile stability S k This information is used to guide subsequent allocation of stockpiles and path planning.

[0093] High-priority stockpiles: The top 30% of stockpiles with the highest priority values;

[0094] Low-priority stockpiles: The bottom 70% of stockpiles with lower priority values.

[0095] In S31, high-priority stockpiles are preferentially allocated to the nearest bucket wheel excavators, including calculating the distance D between stockpile k and the two adjacent bucket wheel excavators. 1k and D 2k According to the priority value P of each stockpile in the priority distribution table k and planar coordinates (x) k y k The calculation is as follows:

[0096] Where (X1, Y1) and (X2, Y2) are the current positions of bucket wheel excavator 1 and bucket wheel excavator 2, respectively. Priority is given to allocating the highest priority stack block k to the nearest bucket wheel excavator i, i.e., the bucket wheel excavator that meets the following conditions:

[0097] i = arg min i∈{1，2} D ik .

[0098] In S32, the avoidance of assigning the same pile of material to two bucket wheel excavators is implemented based on the task allocation independence rule. This ensures that the same pile of material k will not be assigned to two bucket wheel excavators at the same time. Before allocation, it checks whether the pile of material k has already been allocated. If k has already been allocated to bucket wheel excavator i, it is prohibited from being allocated to another bucket wheel excavator, thus ensuring the independence of task allocation.

[0099] S33 avoids idle or overloaded operation of a bucket wheel excavator based on load balancing rules. This is achieved by real-time monitoring of the task progress and allocated material block quantity of both bucket wheel excavators, balancing the task load, and calculating the current allocated material block quantities N1 and N2 for bucket wheel excavators 1 and 2. During the allocation process, if the load of one bucket wheel excavator is significantly higher than that of the other (i.e., N1 - N2 > ΔN), the load will be balanced. max ΔN max If the value is 2), the remaining stockpile blocks are preferentially allocated to the lightly loaded bucket wheel excavators, i.e., i = arg min i∈{1，2} N i , where ΔN max This is the maximum difference threshold for load balancing.

[0100] In S4, based on the stockpiles allocated in S3, the planar coordinates (x, y) of each stockpile are extracted. k y k As path nodes, the set of path nodes assigned to each bucket wheel excavator is sorted according to priority value P. k Sort the nodes from highest to lowest to generate a path node queue. Where i represents the bucket wheel excavator number;

[0101] Path Range Limitation (S41): Path planning for each bucket wheel excavator is performed only within its assigned stacking block, ensuring the coordinates (x, y) of path nodes are limited. k y k The following conditions must be met: in, The range of material stacking blocks allocated to bucket wheel excavator i.

[0102] In S42, path nodes are arranged in descending order of priority, including according to priority queue Q. i Connect the path nodes in sequence to plan the path. Prioritize the retrieval tasks of high-priority stockpiles to ensure efficient path execution.

[0103] Boom length and rotation range constraints (S43): During path planning, the distance from the end of the bucket wheel excavator boom to the path node is calculated to be less than the maximum boom length of the bucket wheel excavator. Based on the rotation range of the bucket wheel excavator, the angle change between path nodes is ensured to be less than the rotation range of the bucket wheel excavator, so as to avoid the path entering unassigned stockpiles or exceeding the reachable range of the bucket wheel excavator.

[0104] S5 specifically includes:

[0105] S51, Recalculation and Reassignment When the Position of a Stockpile Changes: When the position of a stockpile changes (e.g., due to collapse or landslide, i.e., the plane coordinates change from (x...)... k y k ) becomes the new planar coordinates (x) k ′,y k When the distance D between the stockpile and the bucket wheel excavator is recalculated, the distance D between the stockpile and the bucket wheel excavator is recalculated. ik ′, and assign it to the bucket wheel machine that is closest to it after the update;

[0106] Recalculate the distance:

[0107] Among them, D ik ′ represents the Euclidean distance between bucket wheel excavator i and the updated position of stack block k, (X i Y i () represents the current coordinates of bucket wheel machine i;

[0108] S52, Reassignment: Based on the updated distance, assign the stockpile block k to the bucket wheel excavator i that satisfies the following condition: i = argmin i∈{1，2} D ik ′.

[0109] S5 also includes:

[0110] Stockpile Height Update: Recalculate the average height H of the stockpile block k ′:

[0111] Among them, H k ′ is the updated average height of the stockpile, N k ′ represents the number of point clouds contained in the updated stack, z j ′ represents the height of each point in the updated point cloud data within the stockpile;

[0112] Stockpile stability update: Based on the updated state of the stockpile, recalculate its stability S. k ′:

[0113] Where, θ k ′ is the slope angle of the updated stockpile.

[0114] Priority update: Recalculate the priority P of the stockpile. k ′:

[0115] P k ′=ω1·H k ′+ω2·S k ′.

[0116] Update the priority P k Insert a priority distribution table, sort it from highest to lowest priority, and reassign path nodes.

[0117] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0118] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for planning the material handling path in unmanned collaborative operation of a bucket wheel excavator, characterized in that, Includes the following steps: S1. Real-time data of the material yard area is collected by multimodal sensors to construct a three-dimensional stockpile model of the material yard. Based on the working position and working range of adjacent bucket wheel excavators, the overlapping area of ​​adjacent bucket wheel excavators is determined and marked in the three-dimensional stockpile model. S2, divide the stockpile in the overlapping area of ​​the operation into several stockpile blocks, and generate a priority distribution table of the stockpile blocks in the overlapping area by calculating the priority and taking into account the stockpile height and stockpile stability. S2 specifically includes: S21, Block Division: Based on the 3D stacking model of the overlapping area, the overlapping area is divided into several stacking blocks according to a fixed spatial grid size (Δx, Δy). The 3D center coordinates of each stacking block are (x...). k ,y k ,z k ), where z k This indicates the average height of the stockpile; S22, Priority Calculation Parameter Extraction: For each stockpile k, extract the following feature parameters: a) Stacking height H k The average height of the stockpile is calculated using the following formula: Where, N k z represents the number of point cloud data points within the stockpile. i The height of a point within the stockpile; b) Stockpile stability S k The stability coefficient based on the slope of the stockpile is defined as follows: Where, θ k Let θ be the slope angle of the stockpile block k. max The maximum allowable stable slope angle for the stockpile. The ratio of the height difference within the stockpile to the horizontal distance is tan(θ). max The value is defined as the tangent value corresponding to the maximum stable slope of the stockpile. S23, Priority Calculation: Calculate the priority P of each stockpile block by considering both stockpile height and stockpile stability. k :P k =ω1·H k +ω2·S k , where ω1 and ω2 are the weight parameters for priority calculation, reflecting the importance of stockpile height and stockpile stability respectively, satisfying ω1+ω2=1; S24, Generation of the priority distribution table: Based on the priority P of each stockpile. k The stacked blocks within the overlapping area are sorted to generate a priority distribution table, which includes the planar coordinates (x, y) of the stacked blocks. k ,y k Priority value P k Stacking height H k Stockpile stability S k This information is used to guide subsequent allocation of stockpiles and path planning. S3, based on the priority distribution table, allocates the stack blocks in the overlapping operation area to two adjacent bucket wheel excavators. The allocation rules include: S31, high-priority stockpiles are preferentially allocated to bucket wheel excavators that are closest to them; S32, to avoid distributing the same pile of material to two bucket wheel excavators; S33, maintain the balance of material distribution to avoid idle or overloaded operation of a bucket wheel excavator; S4, using the allocation results of S3, plans a preliminary path for each bucket wheel excavator. The path planning must follow: S41, the path of each bucket wheel excavator is limited to the area of ​​its assigned stockpile block; S42, path nodes are arranged in descending order of priority to ensure that material picking tasks are completed according to priority; S43, the path planning takes into account the boom length and rotation range of the bucket wheel excavator to avoid entering unassigned areas; S5, Real-time Material Stacking Pattern Update and Path Adjustment: During the operation of the bucket wheel excavator, when the position of the material stack block in the overlapping area of ​​the operation changes, the distance between the material stack block and the bucket wheel excavator is recalculated and reassigned to the nearest bucket wheel excavator with the updated distance. When the material stacking height or material stacking stability changes, the priority of the material stack block is updated. S5 specifically includes: S51, Recalculation and Reassignment When the Position of the Stockpile Changes: When the position of the stockpile changes, i.e., the plane coordinate changes from (x...) k ,y k ) becomes the new planar coordinates (x) k ′,y k When the distance D between the stockpile and the bucket wheel excavator is recalculated, the distance D between the stockpile and the bucket wheel excavator is recalculated. ik ′, and assign it to the bucket wheel machine that is closest to it after the update; S52, Reassignment: Based on the updated distance, assign the stockpile block k to the bucket wheel excavator i that satisfies the following condition: i = argmin i∈{1,2} D ik ′; The S5 also includes: Stockpile Height Update: Recalculate the average height H of the stockpile block k ′; Stockpile stability update: Based on the updated state of the stockpile, recalculate its stability S. k ′; Priority update: Recalculate the priority P of the stockpile. k ′.

2. The method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator according to claim 1, characterized in that, S1 specifically includes: S11 is equipped with a lidar and camera installed on the bucket wheel excavator to collect real-time data of the material yard area, including the height, density distribution and boundary shape of the material pile, and to perform fusion processing on the collected real-time data; S12, based on the calibrated data, a three-dimensional point cloud model of the material yard area is generated by point cloud processing. Based on the three-dimensional point cloud model, a three-dimensional stockpile model of the material yard is constructed through surface fitting and volume calculation to obtain the spatial distribution, stockpile height and volume information of the stockpile. S13. Based on the operating parameters of the bucket wheel excavator, including boom length, rotation radius and actual working position, calculate the operating coverage of each bucket wheel excavator, and use geometric calculation methods to analyze the overlapping part of the operating range of two adjacent bucket wheel excavators to determine the boundary coordinates of the overlapping area. S14. In the three-dimensional material stacking model, spatially label the determined overlapping areas of operations.

3. The method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator according to claim 2, characterized in that, The high-priority stockpile blocks in S31 are preferentially allocated to the nearest bucket wheel excavators, which includes calculating the distance D between the stockpile block k and the two adjacent bucket wheel excavators. 1k and D 2k According to the priority value P of each stockpile in the priority distribution table k and planar coordinates (x) k ,y k The calculation is as follows: Where (X1,Y1) and (X2,Y2) are the current positions of bucket wheel excavator 1 and bucket wheel excavator 2, respectively. Priority is given to allocating the highest priority stack block k to the nearest bucket wheel excavator i, i.e., the bucket wheel excavator that satisfies the following condition: i = arg min i∈{1,2} D ik .

4. The method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator according to claim 3, characterized in that, The avoidance of allocating the same pile of material to two bucket wheel excavators in S32 is based on the task allocation independence rule. It ensures that the same pile of material k will not be allocated to two bucket wheel excavators at the same time. Before allocation, it checks whether the pile of material k has been allocated. If k has been allocated to bucket wheel excavator i, it is prohibited from being allocated to another bucket wheel excavator, thus ensuring the independence of task allocation.

5. The method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator according to claim 4, characterized in that, The avoidance of idle or overloaded operation of a bucket wheel excavator in S33 is based on load balancing rules. By monitoring the task progress and the number of allocated material blocks of the two bucket wheel excavators in real time, the task load is balanced, and the number of material blocks N1 and N2 currently allocated to bucket wheel excavator 1 and bucket wheel excavator 2 is calculated. During the allocation process, when the load of one bucket wheel excavator is higher than that of the other, the remaining material blocks are preferentially allocated to the bucket wheel excavator with a lighter load.

6. The method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator according to claim 1, characterized in that, In step S4, the planar coordinates (x, y) of each material block are extracted based on the material blocks allocated in step S3. k ,y k As path nodes, the set of path nodes assigned to each bucket wheel excavator is sorted according to priority value P. k Sort the nodes from highest to lowest to generate a path node queue. Where i represents the bucket wheel machine number.

7. The method for planning the material handling path for unmanned collaborative operation of a bucket wheel excavator according to claim 6, characterized in that, In step S42, the path nodes are arranged in descending order of priority, including according to priority queue Q. i Connect the path nodes in sequence to plan the path. Prioritize the retrieval of high-priority stockpiles.

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