Crown block scheduling method

Abstract

The invention provides a crown block scheduling method. The crown block scheduling method comprises the steps of dividing an implementation space according to a task plan; the method comprises the following steps: classifying tasks according to crown block types required by the tasks to obtain a plurality of task groups, then calculating the task priority of each task in each task group in real time, and sorting the tasks from high to low according to the task priorities; all crown blocks with the operation space in the implementation space are obtained, classification is carried out according to crown block types, a plurality of crown block groups are obtained, and the crown block groups and the task groups are associated according to the crown block types needed by the task groups; and matching the tasks in the associated task group with the crown blocks in the crown block group according to a task priority sequence by taking the maximum number of tasks completed in unit time as a target, and then operating the crown blocks according to the requirements of the matched tasks. The problems that in the prior art, a manual scheduling mode is adopted for crown block scheduling, the mode is low in efficiency, depends on the related experience of a crane and cannot guarantee the reasonability of crown block scheduling are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of overhead crane scheduling, and particularly to an overhead crane scheduling method. Background Art

[0002] An overhead crane is a bridge-type crane that runs on an elevated track. It can make full use of the space under the bridge to lift materials without being hindered by ground equipment. It is widely used in indoor and outdoor warehouses, factories, docks, open storage yards, etc. It is the most widely used and most numerous type of lifting machinery. To improve the efficient operation of the production logistics system, it is necessary to reasonably arrange the operations of overhead cranes and efficiently carry out material handling to meet the requirements of each production process. At the same time, when multiple overhead cranes are operating, they cannot cross-operate, and the distance between overhead cranes needs to be greater than the safety distance to ensure safe operation. Therefore, as an important part of enterprise production scheduling, effective overhead crane scheduling plays a crucial role in improving the overall efficiency of the production system.

[0003] Currently, manual scheduling is a commonly used method for actual overhead crane scheduling. A ground signalman is equipped. By observing the operation direction of the overhead crane and production tasks, the double overhead crane is operated through communication equipment or an electric control device to complete the scheduling task. This method has low efficiency, and the signalman needs to be in the operation area to observe and issue instructions during the operation of the overhead crane, which has a large potential safety hazard. Moreover, the quality of scheduling is related to human experience. Therefore, an automated and intelligent scheduling method is urgently needed. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides an overhead crane scheduling method, which solves the problem that in the prior art, manual scheduling is adopted for overhead crane scheduling, which has low efficiency, relies on the relevant experience of signalmen, and cannot ensure the rationality of overhead crane scheduling.

[0005] According to an embodiment of the present invention, an overhead crane scheduling method includes:

[0006] Dividing the implementation space according to the task plan;

[0007] Classifying the tasks according to the type of overhead crane required for the tasks to obtain multiple task groups, then calculating the task priority of each task in each task group in real time, and sorting them from high to low according to the task priority;

[0008] Obtaining all overhead cranes whose operating space is within the implementation space, classifying them according to the type of overhead crane, obtaining multiple overhead crane groups, and associating the overhead crane groups with the task groups according to the type of overhead crane required by the task groups;

[0009] With the goal of completing the largest number of tasks per unit time, the tasks in the associated task group are matched with the overhead cranes in the overhead crane group according to the task priority order, and then the overhead cranes operate according to the needs of the matched tasks.

[0010] Preferably, the method for dividing the implementation space for each task according to the task plan includes:

[0011] Obtain the position information of the work points of each task, then convert the position information of the work points into the scheduling operation range, and calculate the operation time of each task;

[0012] Sort the tasks in ascending order according to the left boundary of the scheduling operation range;

[0013] According to the types of tasks that the overhead crane can execute, divide the tasks into multiple task libraries that can be operated. Then, according to the operation time of each task, calculate the average task volume required for each corresponding overhead crane operation in each task library that can be operated, and add the fluctuating task volume to obtain the task volume range for each overhead crane operation;

[0014] On the premise that the operation volume of each overhead crane is within the task volume range, perform optimization for the overlapping area according to the scheduling operation range of each task, and use the maximum and minimum values of the scheduling operation range when the total area of the overlapping area is the smallest as the implementation space.

[0015] Preferably, the formula for the overlapping area optimization is as follows:

[0016]

[0017] Among them, is the set of the maximum values of the scheduling operation ranges of all tasks assigned to the i-th overhead crane, is the set of the minimum values of the scheduling operation ranges of all tasks assigned to the i-th overhead crane.

[0018] Preferably, the difference between the current moment and the occurrence moment of the task plan is used as the task priority of the task. The smaller the difference, the greater the task priority.

[0019] Preferably, in the same task group, there may be multiple tasks with the same task priority. If there is only one overhead crane in the associated overhead crane group and the task group, and there is only one or multiple tasks with the same priority, it is necessary to check whether the operation space of the overhead crane covers the scheduling operation ranges of all tasks, and place the priority of the tasks whose scheduling operation ranges cannot be covered by the operation space of the overhead crane at the lowest level.

[0020] Preferably, if there is only one crane in the associated crane group and task group, and there are multiple tasks with the same priority, it is necessary to calculate in real time the number of task conflicts between each task to be executed in the task group and the tasks being executed in all task groups. After the task being executed in the current task group is completed, the crane selects the task with the smallest number of task conflicts for execution. If there are multiple tasks with the smallest number of task conflicts, the crane selects the task with the starting point of the task closest to the position of the crane at the current moment for execution.

[0021] Preferably, if there are multiple cranes in the associated crane group and task group, and there is only one task with the same priority, it is necessary to calculate in real time the number of crane conflicts between the cranes in the crane group and the crane executing the task, and select the crane with the smallest number of crane conflicts to execute the task.

[0022] Preferably, if there are multiple cranes in the associated crane group and task group, and there are also multiple tasks with the same priority, calculate in real time the number of task conflicts or spatial overlap degrees between each task to be executed in the task group and the tasks being executed, as well as the number of crane conflicts between the cranes and the crane executing the task. Then, arrange the tasks to be executed in ascending order of the number of task conflicts or spatial overlap degrees, arrange the cranes according to the number of crane conflicts, and match the task with the smallest number of task conflicts with the crane with the smallest number of crane conflicts.

[0023] Preferably, if there are no tasks with the same number of task conflicts, arrange the tasks to be executed in ascending order of the number of task conflicts. If there are tasks with the same number of task conflicts, arrange the tasks to be executed in ascending order of the spatial overlap degree.

[0024] Preferably, the calculation formula for the spatial overlap degree is as follows:

[0025]

[0026] where w is the task to be executed for which the spatial overlap degree is to be calculated, i is other tasks to be executed, X Ew is the maximum value of the task scheduling operation range of the task to be executed w, X Bw is the minimum value of the task scheduling operation range of the task to be executed w, X Ei is the maximum value of the task scheduling operation range of other task i, X Bi is the minimum value of the task scheduling operation range of other task i.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention divides task groups and crane groups according to the types of cranes required for tasks in a task plan, associates the task groups and crane groups, dynamically calculates the task priorities of each task in real time and makes dynamic divisions. At the same time, by calculating the number of task conflicts and the degree of spatial overlap, it is ensured that tasks with the smallest number of task conflicts or the smallest number of spatial overlaps are preferentially executed under the same priority. In addition, by calculating the number of crane conflicts, the arrangement priority of cranes is planned, and the crane with the smallest number of crane conflicts is preferentially allowed to operate first, ensuring that tasks are preferably executed according to the plan while reducing spatial conflicts between tasks as much as possible, and executing as many tasks simultaneously as possible, so as to achieve the goal of completing the largest number of tasks per unit time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the overall flowchart of the crane scheduling according to the embodiment of the present invention.

[0030] Figure 2 It is the flowchart of the crane scheduling in the case of one crane and one task to be executed according to the embodiment of the present invention.

[0031] Figure 3 It is the flowchart of the crane scheduling in the case of one crane and multiple tasks to be executed according to the embodiment of the present invention.

[0032] Figure 4 It is the flowchart of the crane scheduling in the case of multiple cranes and one task to be executed according to the embodiment of the present invention.

[0033] Figure 5 It is the flowchart of the crane scheduling in the case of multiple cranes and multiple tasks to be executed according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The technical solutions in the present invention will be further described below in conjunction with the drawings and embodiments.

[0035] As Figure 1 shown, the embodiment of the present invention proposes a crane scheduling method, including:

[0036] Dividing the implementation space according to the task plan;

[0037] In order to improve the utilization rate of the crane, it is necessary to divide the implementation space of the task according to the task plan, and then select the crane according to the implementation space, so as to avoid the crane only running in a small range after starting.

[0038] First, obtain the main production tasks from the current moment to a period in the future, and convert the main production tasks into scheduling tasks. The information included in the main production tasks are: the location of the work point, the heat number, the steel grade, the work points where each task plan starts to be processed and the planned start time, the work points where each task plan ends to be processed, the planned start time of processing, the planned end time of processing, the task type, and the task quantity.

[0039] Obtain each auxiliary task from the associated auxiliary operation library according to the main production plan, and convert the auxiliary tasks into scheduling tasks. The information included in the auxiliary tasks are: the location of the work point, the work points where each task plan starts to be processed, the work points where each task plan ends to be processed, the task type, and the task quantity.

[0040] Obtain each temporary task from the temporary operation library, and convert the temporary tasks into scheduling tasks. The information included in the scheduling tasks are: the location of the work point, the work points where each task plan starts to be processed, the work points where each task plan ends to be processed, the task type, and the task quantity.

[0041] Based on the work points where each task plan starts to be processed and the work points where each task plan ends to be processed in the main production tasks, auxiliary tasks, and temporary tasks, the scheduling operation range of the corresponding task can be known. Calculate the operation time according to the task quantity. This task time includes the operation time at the task start and end points and the transportation time within the scheduling operation range.

[0042] Then, sort the tasks in ascending order according to the left boundary of the scheduling operation range, and at the same time obtain the size, running safety distance, and executable task types of each overhead crane.

[0043] After that, divide all tasks into multiple executable task libraries of different types according to the executable task types of the overhead cranes and the task types of each task. At this time, to complete all tasks in the executable task library, multiple overhead cranes are required for each executable task library. Then, calculate the average task quantity of each overhead crane in each executable task library according to the operation time of each task average(ρ l ), that is, the sum of the operation times of all tasks in the executable task library divided by the number of overhead cranes that can execute all tasks in the executable task library. Increase the fluctuating task quantity on the basis of the average task quantity to obtain the operation quantity range of each overhead crane: (average(ρ l )×(1 - σ), average(ρ l )×(1 + σ)), where σ generally takes a value of 0.2. In addition, if average(ρ l )×(1 + σ) is greater than or equal to the maximum task quantity ρ max that all overhead cranes can carry, then set the maximum value of the operation quantity range of each overhead crane to ρ max , that is, (average(ρ l)×(1-σ),ρ max )。

[0044] Finally, on the premise that the workload of each overhead crane is within the task volume range, with the goal of minimizing the overlapping area of the overhead crane operations, the overlapping area is optimized according to the scheduling operation range of each task. The overlapping area optimization formula is as follows:

[0045]

[0046] Among them, P(i,j) represents the intersection of the task operation ranges assigned to the i-th overhead crane and the j-th overhead crane, is the set of maximum values of all task scheduling operation ranges assigned to the i-th overhead crane, is the set of minimum values of all task scheduling operation ranges assigned to the i-th overhead crane.

[0047] From this, when the total area of the overlapping area is the least, the operation range area of the overhead crane i is (X Bi ,X Ei ), and this operation range (X Bi ,X Ei ) is used as the implementation space.

[0048] Classify the tasks according to the type of overhead crane required by the tasks to obtain multiple task groups, then calculate the task priority of each task in each task group in real time, and sort them from high to low according to the task priority;

[0049] According to the task (including the above-mentioned main production tasks, auxiliary tasks and temporary tasks) plan, obtain the to-be-executed tasks that have not started to be executed after a delay of δ minutes from the current moment T, that is, within the time period [T, T+δ]. For these to-be-executed tasks, at the starting target points of each task within the time range, there are material units arriving and need to be transported by the overhead crane, and the end target points can all accept the tasks.

[0050] Classify all the to-be-executed tasks according to the type of overhead crane required by the tasks to form multiple task groups, then calculate the time urgency and task priority of each task in each task group. The time urgency is equal to the difference between the current moment and the planned occurrence moment of the to-be-executed task, denoted as θ. At the same time, determine its priority according to the result of θ. The larger the priority value, the higher the priority. The value determination principle is as follows:

[0051] If θ≤0, then the task priority = 100;

[0052] If 0≤θ≤μ, then the task priority = 80;

[0053] If μ≤θ≤2μ, then the task priority = 60;

[0054] If 2μ≤θ, then the task priority = 40.

[0055] According to the above priority division, it can be known that since the time urgency within a certain range is divided into the same priority, there may be multiple tasks to be executed belonging to the same priority in each task group, and then they are sorted according to the task priority from high to low.

[0056] According to the implementation space of the tasks, all overhead cranes whose operating spaces are within the implementation space are obtained, and they are classified according to the type of overhead crane to obtain multiple overhead crane groups. Then, according to the type of overhead crane required by the task group, the overhead crane groups are associated with the task groups. In theory, an overhead crane group must be able to be associated with a task group, but a task group may not be able to be associated with an overhead crane group. Therefore, for the tasks in the task group that cannot be associated with an overhead crane group, the priority of this task is adjusted to the lowest.

[0057] With the goal of maximizing the number of tasks completed per unit time, the tasks in the associated task groups are matched with the overhead cranes in the overhead crane groups in the order of task priority, and then the overhead cranes operate according to the needs of the matched tasks.

[0058] Since the overhead cranes within an overhead crane group have the same type, and there are multiple task priorities for the tasks within a task group, on the premise of giving priority to completing tasks with high task priorities, there are the following 4 situations regarding the number of overhead cranes in an overhead crane group and the number of tasks with the same priority in a task group:

[0059] (1) One overhead crane, one task to be executed

[0060] As Figure 2 shown, in this case, it is necessary to check whether the operating space of the overhead crane covers the scheduling operation range of all tasks. If the scheduling operation range of this task to be executed is within the operating space of this overhead crane, then this overhead crane executes this task to be executed. If the scheduling operation range of this task to be executed is not within the operating space of this overhead crane, then the priority of this task to be executed is set to the lowest, and after all other tasks are completed, this task is associated with other overhead cranes.

[0061] (2) One overhead crane, multiple tasks to be executed

[0062] As Figure 3 shown, in this case, it is necessary to check whether the operating space of the overhead crane covers the scheduling operation range of all tasks. If the scheduling operation range of this task to be executed is not within the operating space of this overhead crane, then the priority of this task to be executed is adjusted to the lowest.

[0063] For the to-be-executed tasks whose scheduling job scope is within the operating space of the overhead crane, since their priorities are the same, it is also necessary to calculate the number of task conflicts between the to-be-executed tasks and the tasks being executed in all task groups, and adjust the execution priorities of the to-be-executed tasks according to the number of task conflicts, so as to avoid excessive conflicts between the to-be-executed tasks and other tasks being executed.

[0064] First, calculate the task coverage range of each to-be-executed task. If the positions of the overhead crane are all greater than the starting point and the ending point of the to-be-executed task, the task coverage range is counted as the minimum value among the position of the to-be-executed overhead crane and the starting point and the ending point of the task; if the positions of the overhead crane are all less than the starting point and the ending point of the task, the task coverage range is counted as the maximum value among the position of the overhead crane and the starting point and the ending point of the task; if the position of the overhead crane is between the starting point and the ending point, the task coverage range is counted as the position of the starting point and the ending point of the overhead crane; sort the task coverage ranges of all to-be-executed tasks in ascending order to form a set of to-be-executed task coverage ranges [X Bw , X Ew .

[0065] If the overhead crane executing the task is in the no-load state, the operating range of the task d being executed is the starting point and the ending point of the task. If the overhead crane executing the task is in the loaded state, the operating range of the task d being executed is the current position and the ending point of the overhead crane. Thus, the task coverage ranges of all tasks being executed can be obtained [X Bd , X Ed .

[0066] Calculate the number of task conflicts between the to-be-executed task w and the task d being executed according to the following formula:

[0067]

[0068] Accumulate the number of task conflicts between the to-be-executed task w and all tasks being executed. If there is only one to-be-executed task with the minimum number of task conflicts, the overhead crane selects the to-be-executed task with the minimum number of task conflicts for execution. If there are multiple to-be-executed tasks with the minimum number of task conflicts, the overhead crane selects the to-be-executed task closest to the position of the overhead crane for execution.

[0069] (3) Multiple overhead cranes, one to-be-executed task

[0070] As Figure 4 shown, this situation is similar to (2). Calculate the number of overhead crane conflicts between the idle overhead crane and the overhead cranes executing tasks in other overhead crane groups, so as to avoid excessive conflicts between the idle overhead crane and other overhead cranes executing tasks when performing tasks.

[0071] Determine the operating direction of the idle overhead crane according to the starting point and the ending point of the to-be-executed task;

[0072] ① If the task direction of other cranes that are currently performing tasks is the same as the running direction of the idle crane:

[0073] If the serial number of the idle crane A is less than the serial number of other cranes that are currently performing tasks (hereinafter referred to as other cranes), then:

[0074] When the starting point of the idle crane A < the end point of other cranes - serial number difference * (crane width + safety distance) and the end point of the idle crane A < the end point of other cranes - serial number difference * (crane width + safety distance), then the crane conflict number = 0, where the serial number difference refers to the serial number difference between the idle crane A and other cranes;

[0075] In other cases, the crane conflict number = the serial number difference between the idle crane A and other cranes.

[0076] If the serial number of the idle crane A is greater than the serial number of other cranes, then:

[0077] When the starting point of the idle crane A > the destination of other cranes + serial number difference * (crane width + safety distance) and the end point of the crane A > the end point of other cranes + serial number difference * (crane width + safety distance), then the crane conflict number = 0;

[0078] In other cases, the crane conflict number = the serial number difference between the idle crane A and other cranes.

[0079] ② If the task direction of other cranes that are currently performing tasks is not the same as the running direction of the idle crane:

[0080] If the serial number of the idle crane A is less than the serial number of other cranes, then:

[0081] When the starting point of the idle crane A < min(set of starting points of other cranes, set of landing points of other cranes) - serial number difference * (crane width + safety distance) and the landing point of the idle crane A < min(set of starting points of other cranes, set of landing points of other cranes) - serial number difference * (crane width + safety distance), then the crane conflict number = 0;

[0082] In other cases, the crane conflict number = the serial number difference between the idle crane A and other cranes.

[0083] If the serial number of the idle crane A is greater than the serial number of other cranes, then:

[0084] When the starting point of the idle crane A > max(set of starting points of other cranes, set of landing points of other cranes) and the landing point of the idle crane A > max(set of starting points of other cranes, set of landing points of other cranes) + serial number difference * (crane width + safety distance), then the crane conflict number = 0;

[0085] In other cases, the crane conflict number = the serial number difference between the idle crane A and other cranes.

[0086] After that, select the idle overhead crane with the minimum number of overhead crane conflicts to execute this task.

[0087] (4) Multiple overhead cranes and multiple tasks to be executed

[0088] As Figure 5 shown, in this case, for the tasks to be executed:

[0089] Count the task coverage range of each task to be executed as the positions of the starting point and the ending point of its scheduling operation range; sort the task coverage ranges of all tasks to be executed in ascending order by value to form a set of task coverage ranges to be executed [X Bw , X Ew , and then calculate the task conflict number of each task to be executed according to the calculation formula in (2).

[0090] If there are no tasks to be executed with the same task conflict number, then sort the tasks to be executed in ascending order of task conflict number, and sequentially select the tasks to be executed with the minimum task conflict number for execution. If there are tasks to be executed with the same task conflict number, then it is also necessary to calculate the spatial folding degree of the tasks to be executed. The spatial folding degree is the size of the overlapping area of the scheduling operation ranges between each task. The smaller the overlapping area, the smaller the conflict.

[0091] The calculation formula for the spatial folding degree is as follows:

[0092]

[0093] Among them, w is the task to be executed for which the spatial overlap degree is to be calculated, i is other tasks to be executed, XEw is the maximum value of the task scheduling operation range of the task to be executed w, XBw is the minimum value of the task scheduling operation range of the task to be executed w, XEi is the maximum value of the task scheduling operation range of other tasks i, and XBi is the minimum value of the task scheduling operation range of other tasks i.

[0094] Sort the tasks to be executed in ascending order of spatial overlap degree, and sequentially select the tasks to be executed with the minimum spatial overlap degree for execution.

[0095] For the overhead crane:

[0096] If there is no idle overhead crane in the overhead crane group, wait until an idle overhead crane appears;

[0097] If there is only one idle overhead crane in the overhead crane group, handle it according to case (1);

[0098] If there are multiple idle overhead cranes in the overhead crane group, handle it according to case (3).

[0099] In summary, by calculating the task conflict number and the spatial overlap degree, tasks with the smallest task conflict number or the smallest spatial overlap number are preferentially executed under the same priority. In addition, by calculating the crane conflict number, the arrangement priority of the cranes is planned, and the crane with the smallest crane conflict number is preferentially allowed to run first, ensuring that while the tasks are selected to be executed as much as possible according to the plan, the spatial conflicts between various tasks are reduced, and as many tasks as possible are executed simultaneously, so as to achieve the goal of completing the largest number of tasks per unit time.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for dispatching an overhead crane, characterized in that: include: Divide the implementation space according to the mission plan; Classify tasks according to the type of overhead crane required for the tasks to obtain multiple task groups, then calculate the task priority of each task in each task group in real time and sort them from high to low according to the task priority; Obtain all the overhead cranes whose operation spaces are within the implementation space, and classify them according to the overhead crane types to obtain multiple overhead crane groups, and associate the overhead crane groups with the task groups according to the overhead crane types required by the task groups; With the goal of completing the maximum number of tasks per unit time, the tasks in the associated task groups are matched with the overhead cranes in the overhead crane group in order of task priority, and then the overhead cranes operate according to the needs of the matched tasks.

2. A method for dispatching an overhead crane according to claim 1, characterized in that: Methods for dividing implementation space for each task according to the task plan include: Obtain the workstation location information of each task, then convert the workstation location information into the scheduling operation range, and calculate the operation time of each task; Sort the tasks from small to large according to the left boundary of the scheduling job scope; According to the types of tasks that can be performed by the crane, the tasks are divided into multiple operable task libraries. Then, according to the operation time of each task, the average task volume required for each crane operation in each operable task library is calculated, and the fluctuating task volume is added to obtain the task volume range of each crane operation. On the premise that the workload of each overhead crane is within the task volume range, the overlapping area is optimized according to the scheduling operation range of each task, and the maximum and minimum values ​​of the scheduling operation range when the total area of ​​the overlapping area is the smallest are used as the implementation space.

3. The method for dispatching an overhead crane according to claim 1, characterized in that: The formula for optimizing the overlapping area is as follows: Among them, P(i,j) represents the intersection of the task operation ranges assigned to the i crane and the j crane. is the maximum set of the scheduling scope of all tasks assigned to each i-th crane, The minimum set of operation scopes for all tasks assigned to the i-th overhead crane.

4. The method for dispatching an overhead crane according to claim 1, characterized in that: The difference between the current time and the time when the task is scheduled to occur is used as the task priority of the task. The smaller the difference, the greater the task priority.

5. A method for dispatching an overhead crane according to claim 2, characterized in that: In the same task group, there may be multiple tasks with the same task priority. If there is only one overhead crane in the associated overhead crane group and task group, and there is only one or more tasks with the same priority, it is necessary to check whether the operating space of the overhead crane covers the scheduling operation range of all tasks, and set the priority of the tasks whose scheduling operation range cannot be covered by the operating space of the overhead crane to the lowest.

6. A method for dispatching an overhead crane according to claim 5, characterized in that: If there is only one overhead crane in the associated overhead crane group and task group, but there are multiple tasks with the same priority, it is necessary to calculate in real time the number of task conflicts between each task to be executed in the task group and the tasks being executed in all task groups. After the tasks being executed in the current task group are completed, the overhead crane selects the task with the smallest number of task conflicts to execute. If there are multiple tasks with the smallest number of task conflicts, the overhead crane selects the task whose task starting point is closest to the overhead crane position at the current moment to execute.

7. The method for dispatching an overhead crane according to claim 2, characterized in that: If there are multiple cranes in the associated crane group and task group, but only one task with the same priority, the number of crane conflicts between the cranes in the crane group and the crane currently executing the task needs to be calculated in real time, and the crane with the smallest number of crane conflicts should be selected to execute the task.

8. The method for dispatching an overhead crane according to claim 2, characterized in that: If there are multiple overhead cranes and multiple tasks with the same priority in the associated overhead crane group and task group, the number of task conflicts or spatial overlaps between each task to be executed and the task being executed in the task group, as well as the number of overhead crane conflicts between the overhead crane and the overhead crane executing the task, are calculated in real time. The tasks to be executed are then arranged in ascending order according to the number of task conflicts or spatial overlaps, and the overhead cranes are arranged according to the number of overhead crane conflicts, and the task with the smallest number of task conflicts is matched with the overhead crane with the smallest number of overhead crane conflicts.

9. A method for dispatching an overhead crane as claimed in claim 8, characterized in that: If there are no tasks with the same number of task conflicts, the tasks to be executed are sorted in the order of the number of task conflicts from small to large. If there are tasks with the same number of task conflicts, the tasks to be executed are sorted in the order of the spatial overlap from small to large.

10. The method for dispatching an overhead crane according to claim 9, characterized in that: The calculation formula of the spatial overlap is as follows: Among them, w is the task to be executed for which the spatial overlap is to be calculated, i is other tasks to be executed, and X Ew is the maximum value of the task scheduling scope of task w to be executed, X Bw is the minimum value of the task scheduling scope of the task w to be executed, X Ei The maximum value of the task scheduling scope for other tasks i, X Bi The minimum value of the task scheduling scope for other tasks i.

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