CN-115829425-B - Virtual unit scheduling method and system based on grouping technology and improved CS algorithm

CN115829425BCN 115829425 BCN115829425 BCN 115829425BCN-115829425-B

Abstract

The invention discloses a virtual unit scheduling method and a system based on a grouping technology and an improved CS algorithm, and belongs to the field of virtual unit scheduling. The method comprises the steps of receiving workpiece groups, machine groups and manufacturing units, dividing the workpiece groups into the same workpiece groups, wherein all components in the workpiece groups are similar in process, machining all the same workpiece groups in the machine groups, the manufacturing units are in one-to-one correspondence with the machine groups, constructing a virtual unit scheduling objective function to minimize the maximum finishing time of all workpiece machining processes, coding the workpiece machining sequences, AGV allocation and intra-unit machine configuration on different machines, solving the coded virtual unit scheduling problem by adopting an improved CS algorithm, introducing the Lewy flight of the self-adaptive flight step length and variable neighborhood search with the self-adaptive bird nest discovery probability, decoding the optimal solution, and outputting a virtual unit scheduling result. The invention can effectively solve the scheduling problem of the virtual unit and can acquire the production scheme with the shortest finishing time as the target.

Inventors

ZHANG LIPING
SUN RUI

Assignees

武汉科技大学

Dates

Publication Date: 20260505
Application Date: 20221223

Claims (5)

1. A virtual unit scheduling method based on a grouping technique and an improved CS algorithm, comprising: acquiring the number of workpieces, the number of machines, the number of AGVs, the number of manufacturing units, the number of steps of each workpiece, the processing time of each step on different machines and the processing sequence of the steps; the method comprises the steps of receiving a workpiece group, a machine group and manufacturing units, wherein all components in the workpiece group are similar in process, all machines in the machine group process the same workpiece group, the manufacturing units are in one-to-one correspondence with the machine group, and the AGV is responsible for transporting workpieces needing cross-unit processing; Constructing an objective function of virtual unit scheduling to minimize the maximum finishing time of all workpiece machining processes; encoding the processing sequence of workpieces on different machines, AGV allocation and machine configuration in a unit; Solving the coded virtual unit scheduling problem by adopting an improved CS algorithm, wherein the improved CS algorithm introduces the Laiweider flight with the self-adaptive flight step length and the variable neighborhood search with the self-adaptive bird nest discovery probability; decoding the optimal solution and outputting a virtual unit scheduling result; wherein the objective function is: The objective function needs to satisfy a constraint condition: ① And (4) restraining working procedures before and after the workpiece: ② Each machine is assigned to a designated unit: ③ The same workpiece can only be processed on one machine at the same time: ④ Time constraints of an AGV in transporting a given workpiece: ⑤ The difference between the total number of units of any unit cannot exceed 2: Wherein, the Representing a workpiece Is the first of (2) Working procedure in machine The end processing time of the upper opportunity machine, Representing a workpiece Is the first of (2) Working procedure in machine The time of the end of the time period, Representing a workpiece Is the first of (2) Working procedure in machine At the start time of the process, the process is started, Representation machine Whether or not to be distributed to the manufacturing unit , Indicating the number of the manufacturing unit, Indicating the number of units to be manufactured, Indicating the serial number of the workpiece, Indicating the number of workpieces to be processed, Representing a workpiece Is characterized by that the number of steps of (a), Representing a workpiece Is used for the number of the working procedures, Representing a workpiece Is the first of (2) Whether or not the working procedure is in the machine The upper part of the processing is processed, Representing a workpiece Is the first of (2) The sequence number of the procedure is Is set to be a start time of the AGV, Representing a workpiece Is the first of (2) The sequence number of the procedure is Is set up to the AGV's travel time, Representing a workpiece Is the first of (2) The sequence number of the procedure is Is set to be a constant value, Indicating the serial number of the processing machine, Representing the number of machines; the coding of the work piece processing sequence, AGV distribution and in-unit machine configuration on different machines comprises the following steps: Four sections of codes are adopted, namely a working procedure section, a machine section, an AGV section and a unit section; Converting the bird nest segment into the working procedure segment according to the reference sequence of the bird nest rotating working procedure segment, wherein the length of the bird nest segment is the total number of working procedures, and the value range of the bird nest segment is 0-1 decimal; for the machine section, randomly selecting one machine from the machine group which can be selected in the corresponding procedure; for AGV segments, the random generation range is Wherein, Representing the total number of AGVs; For the unit sections, the value range is determined according to the corresponding machine of the procedure and the machine-unit distribution scheme Is an integer of (a).
2. The method of claim 1, wherein the adaptive flight step size is calculated as: Wherein, the Representing the actual flight step size of the vehicle, The random step size proposed by Mantegna is shown, Representing the current bird's nest and, Representing the bird nest with the optimal number of current iterations, The control step size is indicated as such, Indicating the total number of iterations that should be performed, Representing the current number of iterations.
3. The method of claim 1, wherein the adaptive bird nest discovery probability is calculated as: Wherein, the The probability of discovery is represented as such, Representing the minimum probability of finding that the device is to be used, Representing the magnitude of the probability of the transformation, Indicating the total number of iterations that should be performed, Representing the current number of iterations.
4. The method of claim 1, wherein the variant-neighbor search is a swap, a transpose, or a pre-insert.
5. A virtual unit scheduling system based on a grouping technology and an improved CS algorithm is characterized by comprising a processor and a memory; The memory is used for storing computer execution instructions; the processor configured to execute the computer-executable instructions such that the method of any one of claims 1 to 4 is performed.

Description

Virtual unit scheduling method and system based on grouping technology and improved CS algorithm Technical Field The invention belongs to the field of virtual unit scheduling, and in particular relates to a virtual unit scheduling method and a virtual unit scheduling system based on a grouping technology and an improved CS algorithm. Background Along with the trend of various domestic and foreign market orders, the requirement of mass production is gradually reduced, so in order to meet the requirements of various small-batch products, the grouping technology is widely applied to the field of manufacturing industry, and most obvious is unit manufacturing, but the switching between each product order can necessarily cause the unit to reconstruct, and the production efficiency and the reconstruction can influence the orderly implementation of actual production. Therefore, a mixed integer mathematical programming model of virtual unit scheduling is proposed herein, which can improve production efficiency, improve equipment utilization, reduce reconstruction cost, and the like when a unit is reconstructed. Compared with the traditional virtual cell scheduling, the method uses three links of cell construction, cell layout and cell scheduling for reference. In the unitized manufacturing process, most researchers only optimize a single problem therein. The method aims at line transformation problems such as the facing sun and aims at minimizing the number of staff and finishing time, unit construction is carried out by considering the relation between workpieces and units, U-shaped unit reconstruction problems such as Ding Xianghai and aims at logistics, construction and time cost and the like are considered, unit scheduling problems which consider the mobile material flow cost among units and the total finishing time of a system are studied by even Yongwei and the like, machine faults are considered in unit scheduling by Zhao Zian and aims at minimizing the comprehensive cost caused by machine faults and the finishing time. In an actual manufacturing system, virtual unit scheduling integration optimization can obtain a better solution set compared with independent decisions, and can effectively and rapidly cope with market demand changes of multiple varieties in small batches. The virtual unit scheduling is dynamically integrated and optimized, the reconstruction cost caused by unit layout is abandoned, and a new virtual unit scheduling model is provided. The virtual unit scheduling problem is an NP-hard problem. The exact algorithm has limitations and is often used to solve small-scale cases. Heuristic algorithms, intelligent optimization algorithms and other methods have achieved great achievements in the field, but as the complexity of the problem increases, improving the solving performance of the problem is still the key point of current research. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a virtual unit scheduling method and a virtual unit scheduling system based on a grouping technology and an improved CS algorithm, which aim to solve the problem that the solution obtained when the prior method solves the problem is not the optimal solution. To achieve the above object, in a first aspect, the present invention provides a virtual unit scheduling method based on a grouping technique and an improved CS algorithm, including: acquiring the number of workpieces, the number of machines, the number of AGVs, the number of manufacturing units, the number of steps of each workpiece, the processing time of each step on different machines and the processing sequence of the steps; the method comprises the steps of receiving a workpiece group, a machine group and manufacturing units, wherein all components in the workpiece group are similar in process, all machines in the machine group process the same workpiece group, the manufacturing units are in one-to-one correspondence with the machine group, and the AGV is responsible for transporting workpieces needing cross-unit processing; Constructing an objective function of virtual unit scheduling to minimize the maximum finishing time of all workpiece machining processes; encoding the processing sequence of workpieces on different machines, AGV allocation and machine configuration in a unit; Solving the coded virtual unit scheduling problem by adopting an improved CS algorithm, wherein the improved CS algorithm introduces the Laiweider flight with the self-adaptive flight step length and the variable neighborhood search with the self-adaptive bird nest discovery probability; and decoding the optimal solution and outputting a virtual unit scheduling result. Preferably, the objective function is: The objective function needs to satisfy a constraint condition: a. And (4) restraining working procedures before and after the workpiece: b. Each machine is assigned to a designated unit: c. the same workpiece can only be processed o