Single crown block scheduling method suitable for single-discharge-port bulk stock bin

Abstract

The invention discloses a single crown block scheduling method suitable for a single-discharge-port bulk stock bin, and belongs to the field of production operation scheduling, the method considers the tight front-back order relation between tasks caused by the spatial position of bulk material storage in the stock bin, the tight front-back order relation between the tasks is determined by judging the spatial position of the tasks, and the scheduling efficiency of the single crown block is improved. It is guaranteed that the obtained scheduling result conforms to logic in the spatial position, and the fluency and efficiency of actual operation are improved; through accurate task planning and path optimization, the operation efficiency can be improved, so that a scheduling scheme is rapidly obtained, the moving distance of the crown block is reduced, the operation efficiency is improved, energy consumption is reduced, and the method is suitable for single-crown-block scheduling of single-discharge-port bulk bins in various situations.

Description

Technical Field

[0001] The present invention belongs to the field of production operation scheduling, and more specifically, relates to a single overhead crane scheduling method applicable to a bulk silo with a single discharge port. Background Art

[0002] Currently, overhead crane operation relies primarily on manual experience and lacks systematic scheduling support, resulting in low efficiency and potential safety hazards. Furthermore, manual operation makes it difficult to precisely control and optimize the operating process, hindering the maximization of overhead crane performance. With the advancement of industrial automation technology, the need to improve operational efficiency and reduce costs is becoming increasingly urgent. Summary of the Invention

[0003] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a single overhead crane scheduling method suitable for a bulk silo with a single discharge port. By scheduling and planning the paths of the tasks performed by the overhead crane, the total moving distance of the overhead crane can be reduced, the operating efficiency can be improved, and the efficient operation of the overhead crane during the operation process can be ensured.

[0004] To achieve the above objectives, according to a first aspect of the present invention, a single overhead crane dispatching method applicable to a bulk silo with a single discharge port is provided, wherein the overhead crane is an electric double-girder bridge grab crane comprising a trolley, a trolley, a hoisting rope, and a grab bucket. The method comprises:

[0005] S1: Merge the remaining task list that was not executed in the previous scheduling with the newly generated task list when the current scheduling is triggered to obtain the total task list of the current job to be performed;

[0006] S2, with any point at the bottom of the silo as the origin, and the horizontal axes parallel to the trolley track, the trolley track, and the lifting rope as the x, y, and z axes, respectively, establish a coordinate system, and divide the silo into three-dimensional grids according to the circumscribed cuboid corresponding to the grab bucket volume; the numbers of the squares where the starting position and target position of task n in the total task list are located in the x, y, and z directions are used as the starting position coordinates P n0 (x n0 ,y n0 ,z n0 ) and target position coordinates P n1 (x n1 ,y n1 ,z n1 ); according to the above coordinates, obtain the set of tasks preceding task n according to the preset rules; take the task n and its preceding task as nodes, use directed edges to represent the order relationship between the tasks corresponding to the two nodes, and construct a task network diagram;

[0007] The preset rules include: if the starting position coordinates P of task n n0 (x n0 ,yn0 ,z n0 ) and the starting position coordinates P of task m m0 (x m0 ,y m0 ,z m0 ) satisfies x n0 =x m0 ,y n0 =y m0 , z n0 =z m0 -1; or, if the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) and the target position coordinates P of task m m1 (x m1 ,y m1 ,z m1 ) satisfies x n1 =x m1 ,y n1 =y m1 , z n1 =z m1 +1; or, the starting position coordinate P of task m m0 (x m0 ,y m0 ,z m0 ) and the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) satisfies x m0 =x n1 ,y m0 =y n1 , z m0 =z n1 , then task m is the immediate predecessor of task n; n = 1, 2, ..., N, m = 1, 2, ..., N, N is the total number of tasks in the total task list;

[0008] S3, initialize the scheduled set S and decision set D to empty sets;

[0009] S4: Put the task with the lowest priority among the tasks corresponding to the node with in-degree 0 in the task network graph into D, and calculate the current position of the overhead crane and the starting position P of each task in D. g0 Distance in the xoy plane Will The smallest task g' is selected as the next task for the overhead crane and is removed from D and placed in S. The current position of the overhead crane is updated to the target position of g'. The node corresponding to g' and all directed edges starting from this node are deleted from the task network graph to update the task network graph. The current position of the overhead crane is represented by the number of the square in the x, y, and z directions. g = 1, 2, ..., G, where G is the total number of tasks in D.

[0010] S5, repeat S4 until the task network diagram is empty, obtain the order in which the overhead crane executes each task in the total task list, and formulate an overhead crane operation schedule based on the start time of each task and the time required to complete each task.

[0011] According to a second aspect of the present invention, there is provided an electronic device comprising: a computer-readable storage medium and a processor;

[0012] The computer-readable storage medium is used to store executable instructions;

[0013] The processor is configured to read the executable instructions stored in the computer-readable storage medium and execute the method according to the first aspect.

[0014] According to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method according to the first aspect.

[0015] According to a fourth aspect of the present invention, there is provided a computer program product comprising a computer program or instructions, which implement the method according to the first aspect when executed by a processor.

[0016] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0017] The scheduling method provided by the present invention takes into account the tight sequence relationship between tasks caused by the spatial position of bulk material storage in the silo. By judging the spatial position of the tasks, the tight sequence relationship between the tasks is determined, ensuring that the obtained scheduling results are logical in terms of spatial position, thereby improving the fluency and efficiency of actual operations; through precise task planning and path optimization, it can improve operation efficiency, thereby quickly obtaining scheduling plans, reducing the moving distance of the overhead crane, improving operation efficiency, and reducing energy consumption. It is suitable for single overhead crane scheduling of bulk silos with a single outlet in various situations.

[0018] As a preferred solution, the method provided by the present invention improves the priority of tasks that have low priority but need to be completed as soon as possible due to spatial location through task priority alignment processing, so that the work content of these tasks themselves is ignored when making task decisions, and these tasks are scheduled as early as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structural plan layout of a bulk silo with a single discharge port provided by an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of three-dimensional meshing of a silo based on a circumscribed cuboid corresponding to the grab bucket's content space, provided by an embodiment of the present invention;

[0021] Figure 3 This is a flowchart of the preceding task search provided by an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the position relationship of tasks in close sequence provided by an embodiment of the present invention;

[0023] Figure 5 is a task network diagram provided by an embodiment of the present invention;

[0024] Figure 6 This is the task priority alignment process provided by an embodiment of the present invention;

[0025] Figure 7 is a task network diagram after task priorities are updated according to an embodiment of the present invention;

[0026] Figure 8 This is a flow chart of a single overhead crane scheduling algorithm provided by an embodiment of the present invention;

[0027] Figure 9 This is a task network diagram after secondary update provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0029] The embodiment of the present invention provides a single overhead crane dispatching method applicable to a bulk silo with a single discharge port, wherein the overhead crane is an electric double-beam bridge grab crane, such as Figure 1 As shown, it includes a large vehicle, a small vehicle, a lifting rope and a grab bucket, and the method includes:

[0030] S1: Merge the remaining task list that was not executed in the previous scheduling with the newly generated task list when the current scheduling is triggered (i.e., the task list formed by the task planning when the current scheduling is triggered) to obtain the total task list of the current job to be completed;

[0031] S2, with any point at the bottom of the silo as the origin, and the horizontal axes parallel to the trolley track, the trolley track, and the lifting rope as the x, y, and z axes, respectively, establish a coordinate system, and divide the silo into three-dimensional grids according to the circumscribed cuboid corresponding to the grab bucket volume; the numbers of the squares where the starting position and target position of task n in the total task list are located in the x, y, and z directions are used as the starting position coordinates P n0 (x n0 ,y n0 ,z n0 ) and target position coordinates P n1 (x n1 ,y n1 ,z n1 ); according to the above coordinates, obtain the set of tasks preceding task n according to the preset rules; take the task n and its preceding task as nodes, use directed edges to represent the order relationship between the tasks corresponding to the two nodes, and construct a task network diagram;

[0032] The preset rules include: if the starting position coordinates P of task n n0 (x n0 ,y n0 ,z n0 ) and the starting position coordinates P of task m m0 (x m0 ,y m0 ,z m0 ) satisfies x n0 =x m0 ,y n0 =y m0 , z n0 =z m0 -1; or, if the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) and the target position coordinates P of task m m1 (x m1 ,y m1 ,z m1 ) satisfies x n1 =x m1 ,y n1 =y m1 , z n1 =z m1 +1; or, the starting position coordinate P of task m m0 (x m0 ,y m0 ,z m0 ) and the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) satisfies x m0 =xn1 ,y m0 =y n1 , z m0 =z n1 , then task m is the immediate predecessor of task n; n = 1, 2, ..., N, m = 1, 2, ..., N, N is the total number of tasks in the total task list;

[0033] S3, initialize the scheduled set S and decision set D to empty sets;

[0034] S4: Put the task with the lowest priority among the tasks corresponding to the node with in-degree 0 in the task network graph into D, and calculate the current position of the overhead crane and the starting position P of each task in D. g0 Distance in the xoy plane Will The smallest task g' is selected as the next task for the overhead crane and is removed from D and placed in S. The current position of the overhead crane is updated to the target position of g'. The node corresponding to g' and all directed edges starting from this node are deleted from the task network graph to update the task network graph. The current position of the overhead crane is represented by the number of the square in the x, y, and z directions. g = 1, 2, ..., G, where G is the total number of tasks in D.

[0035] S5, repeat S4 until the task network diagram is empty, obtain the order in which the overhead crane executes each task in the total task list, and formulate an overhead crane operation schedule based on the start time of each task and the time required to complete each task.

[0036] In step S1, the total task list to be performed is obtained by merging the remaining task list that has not been executed in the previous scheduling and the task list formed by the task planning when the scheduling is triggered.

[0037] The task list information includes: task number, material grabbing operation time, material loosening operation time, starting position, target position and task priority.

[0038] Before S2, the following data preprocessing can be performed in advance to obtain the data required for subsequent task scheduling.

[0039] Get the current position of the overhead crane P c0 , Overhead crane travel speed The fixed height z of the lifting rope and grab before the trolley moves, the distance Δh of the lowest point of the grab's uniform descent above the target position of the overhead crane, and the time when the overhead crane starts working after completing the scheduling (i.e., the task start time); among them, the current position of the overhead crane during initialization is the current position of the overhead crane when no task is executed or the target position of the current task executed by the overhead crane; the task start time is the current moment when the overhead crane is not executing the task after the scheduling is completed or the next moment after the overhead crane completes the task it is currently executing; the travel speed of the overhead crane is the speed at which the trolley, trolley, and grab move Calculate the distance the crane moves when performing each task in the total task list based on the above parameters and the time to complete the task t n .

[0040] The distance moved by the trolley and carriage of the overhead crane is the distance moved by the overhead crane when performing the task, including the distance moved by the overhead crane from the current position to the starting position of the task and the distance moved from the starting position to the target position of the task. The distance of each movement is the distance between the coordinates of the corresponding two positions in the xoy plane; the process of completing a task includes four stages: the overhead crane moves from the current position to the starting position of the task, the lifting rope and grab bucket descend to grab the bulk material and lift it to a fixed height (hereinafter referred to as the "task lifting process"), the overhead crane moves from the starting position of the task to the target position of the task, the lifting rope and grab bucket descend to release the bulk material and lift it to a fixed height (hereinafter referred to as the "task unloading process"). The time to complete the task refers to the sum of the time spent in these four stages. The time to complete the task is the basis for formulating the work schedule.

[0041] The silo is divided into three-dimensional grids according to the circumscribed rectangular parallelepiped corresponding to the grab bucket's storage space. That is, the silo is divided into three-dimensional grids according to the volume of bulk material grabbed by the grab bucket each time. Considering that the bulk material grabbed by the grab bucket is of irregular shape, the volume of the grab bucket's storage space is approximated, and the silo is divided into three-dimensional grids according to its circumscribed rectangular parallelepiped, such as Figure 2 As shown in FIG, after the silo is divided into three-dimensional grids, each grid can be numbered sequentially in the x, y, and z directions to represent the position of each grid in the coordinate system.

[0042] There is a discharge port at one end of the silo and a discharge port at the other end. Above the silo is a track that runs through the entire silo and the discharge port area. The horizontal axes parallel to the trolley track, the trolley track, and the lifting rope are used as the x, y, and z axes to establish a coordinate system. Taking the lower left corner of the silo near the discharge port as the coordinate origin, the horizontal axis along the track direction is the x-axis, and the vertical axis perpendicular to the track direction is the y-axis. The overhead crane consists of a trolley, a trolley, a lifting rope, and a grab bucket. The trolley travels along the x-axis on the track, and the trolley travels along the y-axis on the trolley. The trolley is connected to the grab bucket with a lifting rope and moves up and down along the z-axis to grab and release the bulk materials in the storage position (hereinafter referred to as "grabbing materials" and "loosening materials");

[0043] Among them, the starting position and target position of the task are a storage location coordinate; the storage location coordinate is the number of a fixed-size square in the x, y, and z directions after the silo is gridded. For example, the storage location No. 06 in the x direction, No. 01 in the y direction, and No. 04 in the z direction has the storage location coordinates (6, 1, 4).

[0044] The calculations during preprocessing include:

[0045] (1) The distance between the overhead crane's trolley and the starting position of task n The distance that the overhead crane's trolley and cart move from the starting position of task n to the target position of task n

[0046] Among them, P c0 is the current position of the overhead crane, P n0 is the starting position of task n, P n1 For the target position of task n, the distance moved by the overhead crane's trolley and carriage is replaced by the distance between the two position coordinates in the xoy plane.

[0047] (2) The time it takes for the overhead crane's trolley and carriage to move from their current position to the starting position of task n The time it takes for the overhead crane's trolley and cart to move from the starting position of task n to the target position of task n

[0048] In which, regardless of acceleration, the trolley and the car always move at a constant speed v when empty or loaded. x 、v y The large and small vehicles move at the same time, and the time it takes for the latest of the two directions to reach the target position is the time required for the driving process.

[0049] (3) The time it takes for the overhead crane's trolley and trolley to reach the starting position of task n and then perform the lifting process in task n The time it takes for the overhead crane's trolley and car to reach the target storage location of task n and then unload the task at task n

[0050] The grab bucket does not move simultaneously with the trolley and the small car. z is a fixed height value set during initialization. It does not need to consider the obstacle avoidance between the garbage piles in the silo. Before the trolley and the small car move, the grab bucket is raised to a height z where no interference occurs. After the trolley and the small car of the overhead crane reach the target position, the grab bucket moves at a height of v. z The grab bucket descends at a constant speed to Δh above the target position of the overhead crane, and then decelerates and descends. After completing the grabbing or loosening of the material, it accelerates and rises to the same height and then rises at v z The process of grabbing and loosening materials from the beginning of deceleration to the restoration of uniform speed is defined as the material grabbing or loosening operation. The material grabbing and loosening operation time of task n is given t n 、

[0051] (4) The total time for the overhead crane to complete task n

[0052] In step S3, the predecessor task set of each task is determined according to the predecessor task determination rule, and a task network diagram is generated according to each task and the predecessor task set of each task in the total task list. The task network diagram is a directed graph. The node with sequence number n in the directed graph represents task n, and the directed edge represents the predecessor-successor relationship between the tasks corresponding to the two nodes. The task corresponding to the node before the arrow is the predecessor task of the task corresponding to the node after the arrow.

[0053] It can be understood that the task network diagram is composed of several task networks, and a task network is formed by multiple tasks strung together due to the immediate precedence relationship. That is, the task network diagram includes all nodes in the total task list and the immediate precedence relationship between the nodes.

[0054] The predecessor task determination rules include three rules. The predecessor task determination rules are used to determine the predecessor task set of each task to ensure that the task execution is logical in spatial location.

[0055] The principles of predecessor search include:

[0056] (1) For storage locations that need to be moved out

[0057] Follow the principle of moving out the bulk materials in the upper storage first and then moving out the bulk materials in the lower storage. This order is not subject to priority constraints. That is, if there is a starting position coordinate P of task n n0 (x n0 ,y n0 ,z n0 ) and the starting position coordinates P of task m m0 (x m0 ,y m0 ,z m0 ), there is a spatial relationship x n0 =x m0 ,y n0 =y m0 , z n0 =z m0 -1, then task m is the immediate predecessor of task n and must be completed before task n can be started;

[0058] (2) For storage locations that need to be moved in

[0059] Follow the principle of moving the bulk materials into the lower storage first and then into the upper storage. This order is not subject to priority constraints. That is, if there is a target position coordinate P for task n n1 (x n1 ,y n1 ,z n1 ) and the target position coordinates P of task m m1 (x m1 ,y m1 ,z m1 ), there is a spatial relationship xn1 =x m1 ,y n1 =y m1 , z n1 =z m1 +1, then task m is the immediate predecessor of task n and must be completed before task n can be started;

[0060] (3) For the same storage location

[0061] For the same storage location, the principle of moving out bulk materials first and then moving in bulk materials should be followed. This order is still not subject to priority constraints. That is, if there is a starting position coordinate P of task m m0 (x m0 ,y m0 ,z m0 ) and the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) satisfies x m0 =x n1 ,y m0 =y n1 , z m0 =z n1 , then task m is the predecessor task of task n and must be completed before task n can be started.

[0062] Preferably, after step S2 and before step S3, the method further includes aligning the priorities of the tasks according to the task network diagram:

[0063] S`1, let the task corresponding to a node with out-degree 0 in the task network graph be task e;

[0064] S'2, determine whether task e has a previous task whose priority has not been compared. If so, select any of them as task f, otherwise execute S'4;

[0065] S`3, if the priority of task f is V f Greater than the priority V of task e e , then let V f =V e , execute S`2, otherwise execute S`2 directly;

[0066] S`4, delete the node corresponding to task e and all directed edges ending at this node;

[0067] S`5, determine whether the current task network diagram is empty. If so, complete the processing, otherwise return to S`1.

[0068] Specifically, the task priority alignment operation is performed starting from the last task node of each task network in the task network diagram, and the priority of the immediate predecessor task whose priority value is greater than that of the current task is adjusted to be equal to that of the current task. The task information in the task network diagram is updated according to the result of the task priority alignment until the task network diagram is empty (i.e., there is no node), and the priority alignment process is completed.

[0069] That is, the priority alignment method is to select any task node with an out-degree of 0 in the task network diagram, and perform priority alignment on all the immediate predecessor tasks of the task. After completion, delete the task node and all directed edges with the task node as the end point. Repeat the above operation until the task network diagram is empty, and the task priority alignment operation is completed.

[0070] It is understandable that the task priority can be set by itself as long as it conforms to the priority relationship. It can be set so that the lower the task priority value, the higher the priority; or it can be set so that the lower the task priority value, the lower the priority. Taking the lower the task priority value, the higher the priority as an example, the task priority values include: 1, 2, and 3. The task with a task priority value of 1 is a feeding operation with a fixed target position. The task with a task priority value of 2 is a mixing and siloing operation with a fixed starting position. The task with a task priority value of 3 is a stacking operation.

[0071] Through the above-mentioned task priority alignment, the priority of tasks that have low priority but need to be completed as soon as possible due to spatial location can be increased, so that the work content of these tasks themselves can be ignored when making task decisions and these tasks can be scheduled as early as possible.

[0072] In step S3, the single overhead crane scheduling algorithm provided by the present invention is used to initialize the scheduled set and the decision set, and the task with the lowest priority among the tasks corresponding to the nodes with an in-degree of 0 in the task network diagram is placed in the decision set. Based on the priority rule, the next job to be executed is found in the decision set, and the scheduled set, the decision set and the current position of the overhead crane are updated. The above operation is repeated until all tasks in the task list are in the scheduled set, and the result of this scheduling is obtained.

[0073] The decision set is a set of unscheduled highest priority tasks whose immediate predecessor tasks are already in the scheduled set. The scheduled set contains all assigned tasks and is the scheduling result of each stage.

[0074] Step S3 includes:

[0075] S3.1, initialize the scheduled set S and decision set D to empty sets;

[0076] S3.2, based on the task network diagram and task priority, a decision set D is generated. The tasks in the decision set D meet the following requirements: 1. The task is not in the scheduled set; 2. All of the task's immediate predecessors are in the scheduled set (ensuring that the immediate predecessors are completed before the task); 3. The task is the highest priority task among the tasks that meet requirements 1 and 2. In other words, the task in the decision set is the task with the highest priority among the tasks corresponding to the nodes with in-degree 0 (no directed edge ending at the node) in the task network diagram, that is, B h is the set of tasks immediately preceding task h, g = 1, 2…N, h = 1, 2…N; obtain the current position of the overhead crane and the starting position P of each task in D g0 Distance in the xoy plane Let the next task of the overhead crane be The corresponding task g' is removed from the decision set D and placed in the scheduled set S; if there are multiple tasks that are Then randomly select one task as the next task of the overhead crane; update the current position of the overhead crane to the target position of the newly assigned task, and delete the task node and all directed edges starting from the task node in the task network graph;

[0077] S3.3, determine whether all tasks have been assigned (i.e., whether the task network diagram is empty). If there are still tasks that have not been assigned, proceed to step S3.2; otherwise, proceed to step S3.4.

[0078] S3.4, all tasks have been assigned to the crane, and the scheduled tasks are output in sequence, that is, the order in which the crane executes the tasks, according to the task start time and the time required to complete each task t n Create a homework schedule.

[0079] The method provided by the present invention is further described below by taking a bulk silo with a single discharge port, which is a garbage silo of a garbage incineration power plant, as an example.

[0080] (1) Initialization definition: Summarize the task list and determine the current position P of the overhead crane during this dispatch. c0 , set the moving speed of the cart, trolley and grab The fixed height z of the grab bucket when the trolley is moving, the height Δh of the grab bucket above the target position of the overhead crane before grabbing or loosening the material, and the time when the overhead crane starts to execute the task when the scheduling is completed. The data required for task scheduling is calculated based on the above parameters. and t n .

[0081] For example: The current position of the overhead crane is set to (12,6,25), v x Set to 1m / s, v y Set to 0.8m / s, v zSet to 0.5m / s, z to 25, Δh to 2. After completing this dispatch, the vehicle will start to perform the task at 8:00 am.

[0082] The parameters involved are shown in Table 1.

[0083] Table 1 Parameter list

[0084]

[0085] After the setup is completed, the initial task list is obtained as shown in Table 2.

[0086] Table 2 Initial task list

[0087]

[0088] (2) According to Figure 3 The process shown is used to determine the predecessor task. The specific steps are:

[0089] Select tasks one by one, set the task's immediate predecessor set to an empty set, and compare the starting position and target position of the task with the starting position and target position of all other tasks. The diagram of the position relationship of the immediate predecessor tasks is as follows: Figure 4 As shown, if any of the three preceding task determination rules is met, then the tasks form a preceding-success relationship, and the preceding task is added to the preceding task set until each task has been judged against all other tasks. Table 3 is obtained.

[0090] Table 3 List of sets of precedence and follow-up relations

[0091]

[0092] After the search is completed, the node with the sequence number n represents task n, and the directed edge (arrow) represents the tight sequence relationship between the tasks of two nodes. Based on the tight sequence relationship between tasks, a task network diagram can be preliminarily generated, which contains several task networks. Figure 5 shown.

[0093] (3) After the task network diagram is generated, follow the steps below Figure 6 The process shown is to align task priorities. The specific steps are:

[0094] Step 1: Let a task in the task network that has no immediate subsequent task (task node with out-degree 0) be task e;

[0095] Step 2: Determine whether task e has any predecessor tasks whose priorities have not been compared. If so, select any of them as task f and continue with step 3. Otherwise, proceed to step 5.

[0096] Step 3 Compare the priority V of task f and task ef With V e , if V e <V f , continue to step 4, otherwise, go to step 2;

[0097] Step 4: Let V f =V e , proceed to step 2;

[0098] Step 5: Delete the node corresponding to task e and all edges ending at this node.

[0099] Step 6 determines whether the task network diagram is empty. If so, all task networks have been processed and the process ends. Otherwise, go to step 1.

[0100] The results are shown in Table 4. After completing the task priority alignment, the priority of each task in the original task network diagram is updated, as shown in Figure 7 As shown, at this time, the nodes and directed edges of the task network graph have not changed, but the priorities of the tasks corresponding to the nodes have been aligned.

[0101] Table 4 Task list priority value update

[0102]

[0103] (4) Perform single-day vehicle dispatching, such as Figure 8 The specific steps are as follows: in the initial stage, the scheduled set and decision set are cleared, the task with the lowest priority among the tasks corresponding to the node with in-degree 0 in the task network diagram is placed in the decision set, and based on the priority rule, the task closest to the current position of the overhead crane is selected from the decision set as the next job to be executed, which is removed from the decision set and moved into the scheduled set. The current position of the overhead crane, the task network diagram, and the decision set are updated. The above steps are repeated until all tasks are in the scheduled set, completing the scheduling. The elements of the scheduled set are output in sequence, which is the operation sequence of the overhead crane. Combined with the start time of the overhead crane and the task execution time, the operation schedule of this scheduling is obtained.

[0104] That is, the decision set According to the calculation results of the above steps, we can get choose The corresponding task g' is the next task of the overhead crane, and the scheduled set S = {g'} ∪ S is updated, and the current position of the overhead crane is updated to Update the task network diagram as follows Figure 9 As shown;

[0105] After all tasks are assigned in this way, the updated scheduled set S is obtained, and the elements in it are taken out in sequence to obtain the task execution sequence A.

[0106] The job schedule can be generated based on the duration and start time of the task as shown in Table 5 below.

[0107] Table 5 Assignment schedule

[0108]

[0109] An embodiment of the present invention provides an electronic device, comprising: a computer-readable storage medium and a processor;

[0110] The computer-readable storage medium is used to store executable instructions;

[0111] The processor is configured to read the executable instructions stored in the computer-readable storage medium and execute the method described in any one of the above embodiments.

[0112] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method described in any of the above embodiments.

[0113] An embodiment of the present invention provides a computer program product, including a computer program or instructions, which implements the method described in any of the above embodiments when executed by a processor.

[0114] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for dispatching a single overhead crane for a bulk silo with a single discharge port, wherein the overhead crane is an electric double-beam bridge grab crane, comprising a trolley, a trolley, a lifting rope, and a grab bucket, characterized in that: The method comprises: S1: Merge the remaining task list that was not executed in the previous scheduling with the newly generated task list when the current scheduling is triggered to obtain the total task list of the current job to be performed; S2, with any point at the bottom of the silo as the origin, and the horizontal axes parallel to the trolley track, the trolley track, and the lifting rope as the x, y, and z axes, respectively, establish a coordinate system, and divide the silo into three-dimensional grids according to the circumscribed cuboid corresponding to the grab bucket volume; the numbers of the squares where the starting position and target position of task n in the total task list are located in the x, y, and z directions are used as the starting position coordinates P n0 (x n0 ,y n0 ,z n0 ) and target position coordinates P n1 (x n1 ,y n1 ,z n1 ); according to the above coordinates, obtain the set of tasks preceding task n according to the preset rules; take the task n and its preceding task as nodes, use directed edges to represent the order relationship between the tasks corresponding to the two nodes, and construct a task network diagram; The preset rules include: if the starting position coordinates P of task n n0 (x n0 ,y n0 ,z n0 ) and the starting position coordinates P of task m m0 (x m0 ,y m0 ,z m0 ) satisfies x n0 =x m0 ,y n0 =y m0 , z n0 =z m0 -1; or, if the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) and the target position coordinates P of task m m1 (x m1 ,y m1 ,z m1 ) satisfies x n1 =x m1 ,y n1 =y m1 , z n1 =z m1 +1; or, the starting position coordinate P of task m m0 (x m0 ,y m0 ,z m0 ) and the target position coordinates P of task n n1 (x n1 ,y n1 ,z n1 ) satisfies x m0 =x n1 ,y m0 =y n1 , z m0 =z n1 , then task m is the immediate predecessor of task n; n = 1, 2, ..., N, m = 1, 2, ..., N, N is the total number of tasks in the total task list; S3, initialize the scheduled set S and decision set D to empty sets; S4: Put the task with the lowest priority among the tasks corresponding to the node with in-degree 0 in the task network graph into D, and calculate the current position of the overhead crane and the starting position P of each task in D. g0 Distance in the xoy plane Will The smallest task g' is selected as the next task for the overhead crane and is removed from D and placed in S. The current position of the overhead crane is updated to the target position of g'. The node corresponding to g' and all directed edges starting from this node are deleted from the task network graph to update the task network graph. The current position of the overhead crane is represented by the number of the square in the x, y, and z directions. g = 1, 2, ..., G, where G is the total number of tasks in D. S5, repeat S4 until the task network diagram is empty, obtain the order in which the overhead crane executes each task in the total task list, and formulate an overhead crane operation schedule based on the start time of each task and the time required to complete each task.

2. The method according to claim 1, wherein After step S2 and before step S3, the process further includes aligning the priorities of the tasks according to the task network diagram: S`1, let the task corresponding to a node with out-degree 0 in the task network graph be task e; S'2, determine whether task e has a previous task whose priority has not been compared. If so, select any of them as task f, otherwise execute S'4; e = 1, 2 ... N, f = 1, 2 ... N; S`3, if the priority of task f is V f Greater than the priority V of task e e , then let V f =V e , execute S`2, otherwise execute S`2 directly; S`4, delete the node corresponding to task e and all directed edges ending at this node; S`5, determine whether the current task network diagram is empty. If so, complete the processing, otherwise return to S`1.

3. The method according to claim 1 or 2, wherein: In step S3, if there are multiple The smallest task is randomly selected as the next task to be executed by the overhead crane.

4. The method according to claim 1, wherein The total time for the crane to complete task n in, v x 、v y 、v z are the moving speeds of the trolley, car and grab respectively, P c0x 、P c0y are the numbers of the grid where the overhead crane is currently located in the x and y directions, t n 、 are the material grabbing and loosening operation times of task n, z is the fixed height value of the grab bucket set during initialization, and Δh is the distance between the grab bucket and the target position of the overhead crane before it decelerates and descends.

5. An electronic device, characterized in that: include: Computer-readable storage medium and processor; The computer-readable storage medium is used to store executable instructions; The processor is configured to read the executable instructions stored in the computer-readable storage medium and execute the method according to any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method according to any one of claims 1 to 4.

7. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

Images