Steel pipe flexible conveying scheduling method and system

Abstract

This invention relates to the field of industrial automation production technology, specifically to a flexible steel pipe conveying and scheduling method and system. The method includes: acquiring real-time status data of multiple workstations in the production line, including the status of each workstation and the number of steel pipes in the input buffer; based on the status of each workstation, determining the tasks to be conveyed between the source workstation of the steel pipes that have been processed and the target workstation that is idle; calculating the global scheduling priority of each task to be conveyed; and selecting the task with the highest global scheduling priority for execution. In other words, the solution of this invention can improve the operating efficiency and equipment utilization rate of the entire production line.

Description

Technical Field

[0001] This invention relates to the field of industrial automation production technology, specifically to a flexible steel pipe conveying and scheduling method and system. Background Technology

[0002] In modern steel pipe manufacturing processes, steel pipes need to be transferred between multiple different workstations (such as cutting, grinding, heat treatment, quality inspection, etc.). To improve production efficiency and automation, factories typically deploy automated conveying equipment, such as overhead cranes and automated guided vehicles (AGVs), in conjunction with a manufacturing execution system (MES) to schedule the conveying of steel pipes.

[0003] The common technical approach currently is to use sensors deployed at each workstation and input buffer to monitor the production line status in real time, such as whether a workstation is idle and the amount of material in the buffer. Once a workstation completes processing, the scheduling system decides on the next task to be transported based on a set of preset fixed rules or static priorities. For example, it may adopt a "first-in, first-out" principle or prioritize transporting steel pipes to any downstream workstation that is currently idle.

[0004] However, the aforementioned techniques have significant limitations in practical applications. Essentially, the scheduling method is a "greedy" strategy, relying solely on the current, local state of affairs—for example, considering only "which workstation has completed its task" and "which target workstation is currently idle." This approach ignores the impact of the task to be transported on the subsequent state of the entire production line, lacking a global perspective. As a result, while the transport decisions may seem reasonable locally and in the short term, they often lead to imbalances in the production process globally and in the long term. Material congestion quickly forms in front of some popular or slow-processing workstations; simultaneously, upstream materials for other workstations are prematurely reassigned, causing them to enter a prolonged "idle waiting" state.

[0005] The coexistence of congestion and idleness mentioned above severely restricts the overall equipment utilization rate and total output efficiency of the production line, making it impossible to achieve globally optimal flexible production scheduling. Summary of the Invention

[0006] The purpose of this invention is to propose a flexible steel pipe conveying and scheduling method and system to solve the problems of global production process imbalance and low efficiency caused by local greedy strategies in the steel pipe scheduling process of the prior art; to this end, this invention provides solutions in the following two aspects.

[0007] In a first aspect, the present invention provides a flexible steel pipe conveying scheduling method, comprising:

[0008] Acquire real-time status data of multiple workstations in the production line, including the status of each workstation and the number of steel pipes in the input buffer area;

[0009] Based on the status of each workstation, determine the tasks to be transported between the source workstation of the steel pipes that have been processed and the target workstation that is in an idle state on the production line.

[0010] Calculate the global scheduling priority of each task to be delivered;

[0011] Select the task with the highest global scheduling priority for execution;

[0012] Among them, the global scheduling priority is positively correlated with the pre-acquired call value and the global equilibrium contribution; the call value is positively correlated with the downstream idle index and negatively correlated with the total time cost required to complete the task to be transported; the downstream idle index is positively correlated with the ratio of the maximum capacity of the input buffer of each downstream workstation of the target workstation to the current number of steel pipes; the global equilibrium contribution is the difference between the variance of the material occupancy rate of the input buffer of all workstations on the production line before the task to be transported is executed and the variance of the virtual material occupancy rate after one virtual execution of the task to be transported.

[0013] The above solution comprehensively considers the value of the call and the global balance contribution to the overall material distribution of the production line. It can make decisions from a global and predictive perspective, effectively avoiding the problems of material distribution imbalance, congestion at some workstations and idle workstations caused by traditional methods, and significantly improving the operating efficiency and equipment utilization of the entire production line.

[0014] Optionally, the global scheduling priority is:

[0015] ;

[0016] in, To the source work station Reach the target workstation The global scheduling priority of the tasks to be delivered; To the source work station Reach the target workstation The invocation value of the task to be delivered; To the source work station Reach the target workstation The global balanced contribution of the tasks to be delivered.

[0017] The global scheduling priority in the above scheme enables the decision-making to focus not only on the individual value of tasks, but also on their optimization effect on global delivery.

[0018] Optionally, the real-time status data may also include: the current position of the conveying equipment, the maximum capacity of the input buffer area at each workstation, and the standard processing cycle of the steel pipe at each workstation.

[0019] Optionally, the total time cost is the sum of the first conveying time, the remaining processing time, and the second conveying time; the first conveying time is the time required to travel from the current position of the nearest idle conveying equipment to the source station; the remaining processing time is the difference between the standard processing cycle of the steel pipe in the source station and the time already processed; if the processing of the steel pipe has been completed, the remaining processing time is 0; the second conveying time is the time required for the idle conveying equipment to transport the steel pipe from the source station to the target station.

[0020] The total time cost mentioned above accurately reflects the time required to execute a task to be delivered and provides reliable data for cost-benefit assessment of subsequent scheduling decisions.

[0021] Optionally, the invocation value for:

[0022] ;

[0023] in, For the target workstation Downstream idle index; It is the distance from the source workstation The current position of the nearest idle conveyor v; The conveyor equipment v is from the current position Move to the source station Required first delivery time; Source workstation The remaining processing time for the steel pipe; The conveying equipment v moves the steel pipe from the source station Transport to the target workstation The required second delivery time, , Source workstation The coordinates of the target workstation j.

[0024] The aforementioned call value can be used to evaluate different tasks to be delivered.

[0025] Optionally, the downstream idle index is:

[0026] ;

[0027] in, For the target workstation Downstream idle index; Target workstation The set of all downstream workstations; It is the collection of all downstream workstations. The number of intermediate workstations; It is the downstream work station Maximum capacity of the input buffer; It is the downstream work station The current number of steel pipes in the input buffer.

[0028] The downstream idle index of the above scheme can predict the potential shutdown risk of the production line downstream, thereby delivering materials to the critical bottleneck path in advance and effectively preventing the chain shutdown problem caused by local material shortage.

[0029] Optionally, each downstream station of the target station is obtained by acquiring the static topology information of the production line, which includes the process path diagram of each station and its directly connected downstream stations.

[0030] Optionally, the status of each workstation includes working, idle, and faulty.

[0031] Optionally, selecting the task to be transported with the highest global scheduling priority for execution includes: sending control commands to the control systems of the corresponding conveying equipment and related workstations to complete the scheduling; and returning to the step of obtaining the real-time status data to perform a new round of scheduling.

[0032] In the second aspect, a flexible steel pipe conveying and scheduling system includes:

[0033] processor;

[0034] The memory stores computer instructions for a flexible steel pipe conveying scheduling method, which, when executed by the processor, causes the system to perform the aforementioned flexible steel pipe conveying scheduling method.

[0035] The beneficial effects of this invention are as follows:

[0036] The present invention takes a global and predictive approach, obtains the global scheduling priority of each conveying task, and schedules the corresponding conveying tasks according to the global scheduling priority. This can solve the problems of material distribution imbalance, congestion at some workstations, and idleness at some workstations in the production line, thereby improving the conveying efficiency of steel pipes. Attached Figure Description

[0037] Figure 1 This schematically illustrates a flowchart of the steps of a flexible steel pipe conveying and scheduling method in this embodiment;

[0038] Figure 2 The schematic diagram illustrates a structural block diagram of a flexible steel pipe conveying and scheduling system in this embodiment. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0040] The present invention provides a flexible steel pipe conveying scheduling method and system that can dynamically evaluate the contribution of each potential conveying task to the overall balance of the production line, thereby making more efficient scheduling decisions.

[0041] like Figure 1 As shown, a flexible steel pipe conveying and scheduling method in this embodiment includes the following steps:

[0042] Step S1: Collect real-time status data of steel pipes on the production line.

[0043] In this embodiment, data interface is established with the factory's Manufacturing Execution System (MES) and field sensor network to periodically acquire real-time status data of the steel pipe throughout the production line. This real-time status data includes:

[0044] The status of each workstation, including "working", "idle", "malfunctioning", etc.;

[0045] The number of steel pipes in the input buffer of each workstation;

[0046] The status of each conveying device, including its current position. "Busy / Idle" status, among which, The coordinates of the current position;

[0047] The collection of steel pipes to be scheduled, the current position of each steel pipe, and the next processing step to be completed.

[0048] In addition, it is necessary to obtain the static topology information and process parameters of the production line, specifically including:

[0049] Maximum capacity of the input buffer for each workstation;

[0050] Standard processing cycle for steel pipes at each workstation;

[0051] The process path diagram of the production line, that is, the set of all possible direct downstream stations for each station;

[0052] Based on the factory layout diagram, the first conveying time between any two stations of the conveying equipment when conveying steel pipes is obtained.

[0053] Step S2: Calculate the global scheduling priority of each task to be delivered.

[0054] In this embodiment, when there is at least one steel pipe that has been processed (located at the source station) (and at least one available target station capable of receiving the steel pipe) At that time, the system does not immediately execute the delivery, but instead prepares for each possible delivery from the source station. Reach the target workstation The tasks to be delivered are analyzed from local to global perspectives, and their global scheduling priority is calculated.

[0055] Specifically, the process of obtaining the global scheduling priority is as follows:

[0056] Step S21: Calculate the downstream idle index of the target workstation.

[0057] To assess the priority of supplying steel pipes to an idle workstation, this invention considers not only whether the workstation itself is idle, but also whether downstream workstations are also at risk of shutdown. For example, if the target workstation... Downstream workstations The input buffer will also be cleared soon, so please prepare the input buffer for the target workstation in time. Replenishing materials can prevent the production chain from reversing from the target workstation. A series of work stoppages began to occur.

[0058] Therefore, this embodiment constructs a downstream idle index. To assess the risk of potential work stoppages.

[0059] Specifically, target workstation Downstream idle index for:

[0060] ;

[0061] in, Target workstation The direct downstream workstation set, It is the collection of all downstream workstations. The number of intermediate workstations It is the downstream work station Maximum capacity of the input buffer It is the downstream work station The input buffer contains the current number of steel pipes, and j is the sequence number of the target workstation.

[0062] In the above formula, when the downstream station The current number of steel pipes in the input buffer The smaller, The larger the value, the better for the downstream workstation. The greater the free time, the better. The higher the value, the better it indicates the target workstation. The higher the priority of the transport steel pipes, the lower the potential risk of production interruption.

[0063] Step S22: Calculate the call value of the task to be delivered.

[0064] It should be noted that even if the destination of a transport task is very idle, if the transport equipment performing the task is far away, the time consumption will be significant, thus reducing the transport efficiency of the steel pipes. Therefore, after obtaining the downstream idle index of each target workstation, it is also necessary to assess the comprehensive value of the transport task by combining it with the total time cost required to complete the task. That is, to calculate the call value of the transport task, which aims to balance the benefits of the task (meeting urgent needs) with the total time cost (transport time).

[0065] In this embodiment, the call value is directly proportional to the downstream idle index and inversely proportional to the total time cost.

[0066] Specifically, for a source workstation Reach the target workstation The pending delivery task, its call value The calculation formula is:

[0067] ;

[0068] in, To the source work station To the target workstation The call value of the task to be delivered. For the target workstation Downstream idle index, It is the distance from the source workstation The current position of the nearest available conveyor v. The conveyor equipment v is from the current position Source workstation The required first delivery time, Source workstation The remaining processing time for the steel pipe. The conveying equipment v moves the steel pipe from the source station Transport to the target workstation The required second delivery time, , Source workstation The coordinates of the target workstation j.

[0069] In the above formula, the remaining processing time represents the time the equipment needs to wait. If the steel pipe processing is completed, the remaining processing time is 0. The denominator represents the total time cost of completing the task to be conveyed (including the scheduling time of the conveying equipment, possible waiting time, and conveying time).

[0070] The higher the downstream idle index of the target workstation and the shorter the total time cost to complete the delivery, the higher the call value of the delivery task.

[0071] Step S23: Calculate the global balance contribution of the task to be delivered and obtain the global scheduling priority.

[0072] Since the optimal production state is one where the load on all workstations is relatively balanced, and materials flow smoothly on the production line, this embodiment also introduces a global perspective after obtaining the call value of each task to be conveyed. This involves calculating the global balance contribution to assess the impact of executing a task on the material distribution balance of the entire production line.

[0073] The process of obtaining the global equilibrium contribution is as follows:

[0074] First, calculate the load imbalance of the input buffers for all workstations on the production line.

[0075] This load imbalance is typically represented by the variance of buffer occupancy. Buffer occupancy is the ratio of the number of steel pipes in the input buffer of each workstation to the maximum capacity of the corresponding input buffer.

[0076] Secondly, for a source workstation Reach the target workstation After a virtual execution of the task to be transported, the virtual imbalance of the production line after the task is executed is calculated.

[0077] The virtual imbalance mentioned above is the variance of cache occupancy after one virtual execution.

[0078] The above virtual execution assumes that the execution starts from the source workstation once. Reach the target workstation The tasks to be delivered, after virtual execution at the source workstation The output buffer steel pipe is reduced by one, and the target station is... The number of steel pipes in the input buffer is increased by one.

[0079] Then, the global equilibrium contribution is calculated.

[0080] In this embodiment, the global balance contribution is the difference between the load imbalance and the virtual imbalance.

[0081] If the overall imbalance of the conveying schedule decreases after the task to be conveyed is executed, that is, the virtual imbalance is less than the load imbalance, the global balance contribution is a positive value, which means that the task to be conveyed has a positive contribution to the balance of the production line. That is, the greater the contribution, the more significant the effect of the task to be conveyed on smoothing the material distribution of the production line.

[0082] In this embodiment, the global scheduling priority of each task to be delivered is calculated by combining the call value and the global balanced contribution, specifically as follows:

[0083] ;

[0084] in, From the source work station Reach the target workstation The global scheduling priority of the tasks to be delivered. From the source work station Reach the target workstation The call value of the task to be delivered. From the source work station Reach the target workstation The global balanced contribution of the tasks to be delivered.

[0085] The above formula takes the value of the task of transporting the steel pipe itself as the basis, and uses a gain factor determined by the global equilibrium contribution. Scale up or down when the task to be conveyed can significantly improve the balance of the production line ( If the value is a large positive number, its global scheduling priority will be significantly increased; conversely, if the task to be delivered will exacerbate the imbalance during delivery ( If the value is negative, its global scheduling priority will be suppressed.

[0086] The aforementioned global scheduling priority ensures that scheduling decisions consider not only the value of individual tasks but also their impact on global delivery.

[0087] Step S3: Execute the task with the highest global scheduling priority to be delivered.

[0088] After obtaining the global scheduling priority of all tasks to be transported, the task with the highest global scheduling priority is selected for execution, i.e., sent to the corresponding transport device. The system sends instructions to the control system (such as PLC) to complete the transportation and scheduling of the steel pipes.

[0089] After completing one scheduling cycle, the system returns to step S1 and starts a new round of scheduling decision loop based on the updated production line status.

[0090] The solution of this invention introduces a global equilibrium contribution, which links each scheduling decision with the overall material distribution status of the production line. This effectively avoids the problem of congestion and idleness caused by local greedy strategies, and enables materials to flow more smoothly and evenly throughout the production line. This significantly reduces the waiting time at workstations caused by improper material allocation and improves the overall output efficiency and throughput of the production line.

[0091] This invention also provides a flexible steel pipe conveying and scheduling system. For example... Figure 2 As shown, the system includes a processor and a memory, the memory storing computer program instructions, which, when executed by the processor, implement the flexible steel pipe conveying scheduling method described above according to the present invention.

[0092] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and therefore will not be described in detail here.

[0093] In this invention, the aforementioned memory can be any tangible medium containing or storing a program that can be used or combined with an instruction execution system, apparatus, or device. For example, a computer-readable storage medium can be any suitable magnetic or magneto-optical storage medium, such as Resistive Random Access Memory (RRAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Enhanced Dynamic Random Access Memory (EDRAM), High-Bandwidth Memory (HBM), Hybrid Memory Cube (HMC), etc., or any other medium that can be used to store desired information and can be accessed by an application, module, or both. Any such computer storage medium can be part of a device or accessible to or connected to a device. Any application or module described in this invention can be implemented by computer-readable / executable instructions stored or otherwise maintained on such a computer-readable medium.

[0094] In the description of this specification, "multiple" means at least two, such as two, three or more, etc., unless otherwise expressly and specifically defined.

[0095] While various embodiments of the invention have been shown and described in this specification, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention.

Claims

1. A flexible steel pipe conveying and scheduling method, characterized in that, include: Acquire real-time status data of multiple workstations in the production line, including the status of each workstation, the number of steel pipes in the input buffer, the current position of the conveying equipment, the maximum capacity of the input buffer of each workstation, and the standard processing cycle of the steel pipes at each workstation; Based on the status of each workstation, determine the tasks to be transported between the source workstation of the steel pipes that have been processed and the target workstation that is in an idle state on the production line. Calculate the global scheduling priority of each task to be delivered; Select the task with the highest global scheduling priority for execution; Among them, the global scheduling priority is positively correlated with the pre-acquired call value and the global balanced contribution. The value of the call for: ； in, For the target workstation Downstream idle index; It is the distance from the source workstation The current position of the nearest idle conveyor v; The conveyor equipment v is from the current position Move to the source station Required first delivery time; Source workstation The remaining processing time for the steel pipe; The conveying equipment v moves the steel pipe from the source station Transport to the target workstation The required second delivery time, , Source workstation The coordinates of the target workstation j; The downstream idle index is: ； in, For the target workstation Downstream idle index; Target workstation The set of all downstream workstations; It is the collection of all downstream workstations. The number of intermediate workstations; It is the downstream work station Maximum capacity of the input buffer; It is the downstream work station The current number of steel pipes in the input buffer; The global equilibrium contribution is the difference between the variance of the material occupancy rate of the input buffer area of ​​all workstations on the production line before the delivery task is executed and the variance of the virtual material occupancy rate after one virtual execution of the delivery task. The global scheduling priority is: ； in, To the source work station Reach the target workstation The global scheduling priority of the tasks to be delivered; To the source work station Reach the target workstation The invocation value of the task to be delivered; To the source work station Reach the target workstation The global balanced contribution of the tasks to be delivered.

2. The flexible steel pipe conveying and scheduling method according to claim 1, characterized in that, The first conveying time is the time required for the current position of the idle conveying equipment closest to the source station to reach the source station; the remaining processing time is the difference between the standard processing cycle of the steel pipe in the source station and the processing time already completed. If the processing of the steel pipe has been completed, the remaining processing time is 0; the second conveying time is the time required for the idle conveying equipment to transport the steel pipe from the source station to the target station.

3. The flexible steel pipe conveying and scheduling method according to claim 1, characterized in that, The downstream stations of the target station are obtained by acquiring the static topology information of the production line, which includes the process path diagram of each station and its directly connected downstream stations.

4. The flexible steel pipe conveying and scheduling method according to claim 1, characterized in that, The status of each workstation includes working, idle, and faulty.

5. The flexible steel pipe conveying and scheduling method according to claim 1, characterized in that, The step of selecting the task to be transported with the highest global scheduling priority for execution includes: sending control commands to the control systems of the corresponding conveying equipment and workstation to complete the scheduling; and returning to the step of obtaining the real-time status data to perform a new round of scheduling.

6. A flexible steel pipe conveying and dispatching system, characterized in that, include: processor; A memory storing computer instructions for a flexible steel pipe conveying scheduling method, which, when executed by the processor, causes the system to perform a flexible steel pipe conveying scheduling method according to any one of claims 1-5.

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