基于遗传算法的车间作业调度问题求解

文章提出了一个求解车间作业调度问题的完备的、强壮的遗传算法。在分析车间作业调度问题的数学模型的基础上,给出了:(1)采用分段结构的染色体编码思想;(2)生成可行调度的算法;(3)计算调度目标函数的算法;(4)三种遗传算子及其辅助算子———修正算子的设计。最后,通过仿真验证了算法的有效性和稳定性。     

关于车间作业调度的组合优化算法

车间调度问题由于具有重要的理论和实用价值吸引了很多研究者的兴趣,但一个复杂的车间调度不仅可能涉及到成千上万道车间调度工序,而且工序的变更又可能导致相当大的调度规模.本文针对调度提出了一种改进的遗传算法,该算法引入了生物界DNA的思想将染色体分为双链,并在一个制造企业软件系统中应用了此算法.     

基于改进变异算子的遗传算法求解柔性作业车间调度①

柔性作业车间调度问题是对传统车间调度问题的扩充,它更接近于现实的生产调度问题。针对柔性作业车间调度的特点,设计了基于关键工序的变异算子,使变异集中于关键路径,从而提高了变异过程的效率。还采用二向量编码、初始种群定位法和POX交叉算子,设计了新的应用于柔性作业车间调度的遗传算法,并通过实验验证了算法的有效性。     

遗传算法的双向车间作业调度算法研究

将双向调度思想应用于作业车间调度,得到一种新调度算法。算法中关键零件采用反向调度,尽可能地满足交货期要求,一般零件采用前向调度方法,最大效率地利用车间资源,尽可能早完工。利用遗传算法的全局搜索特性,得到最佳的调度结果。     

基于演化策略算法的作业车间调度优化

提出一种基于工件操作次序的二维实数编码方法,采用演化策略算法求解作业车间调度问题。设计一种基于三点交叉互换的重组算子用于生成子代个体,并采用个体编码基因随机重新生成的方法设计变异算子。实验结果证明,演化策略算法能有效优化作业车间调度问题,与遗传算法和粒子群优化算法相比,其优化性能更好,并且基于三点交叉互换重组算子的演化策略算法的性能好于基于两点交叉和基于四点交叉互换重组算子的演化策略算法。     

车间作业调度遗传算法中的交叉算子研究

针对车间作业调度遗传算法，在车间作业调度数学表达模型基础上，讨论车间作业调度遗传算法交叉算子的宏观设计与微观设计，提出了ＪＳＳ（ＪｏｂＳｈｏｐＳｃｈｅｄｕｌｉｎｇ）交叉算子设计原则，并给出其应用结论，说明了交叉算子设计的有效性。     

车间作业调度遗传算法中的编码研究

首先讨论了车间作业调度数学表达模型，然后提出了车间作业高度基因等概念，接着详细论述了ＪＳＳ连锁基因编码法的机理，最后给出了ＪＳＳ连锁基因编码法的实施步骤并说明了ＪＳＳ连锁基因编码法的可行性。     

求解车间作业调度问题的混合遗传模拟退火算法

为了克服传统遗传算法解决车间作业调度问题的局限性,结合遗传算法(GA)和模拟退火算法(SA)的优点,提出一种混合遗传模拟退火算法(GASA),以便高效地解决车间作业调度问题.该算法既发挥了遗传算法收敛速度快、模拟退火算法搜索面广的优点,又克服了前者收敛容易早熟而后者收敛速度较慢的问题.在算法的操作细节上,加入自适应调整的遗传操作及最优个体保留策略,以及增加记忆功能的模拟退火操作与收敛准则.从而既防止了算法会陷入局部最优解的问题,又提高了算法的收敛速度及搜索效率.将提出的混合遗传模拟退火算法(GASA)应用于Muth和Thompson基准问题的实验运行,证明了该算法的高效性和有效性.     

基于混合遗传算法的作业车间调度问题的研究与仿真

作业车间调度问题(JSP)是一类典型的NP-hard问题,遗传算法(GA)由于其隐合并行性和全局解空间搜索两大优点而成为解决JSP问题的常用工具.但是,由于JSP问题本身的特点,普通遗传算法难以在解此类问题时得到满意解,最突出的问题就是过早收敛于某一局部最优解,使算法效率降低.在此基础上,将遗传算法和模拟退火算法相结合,提出了一种基于遗传和模拟退火的混合算法,该算法将模拟退火算法赋予搜索过程时变性融入其中,具有明显的概率跳跃性,并选取了典型问题进行分析和仿真研究.仿真结果表明,与传统的遗传算法相比该方法是行之有效的.     

一种基于混合遗传算法的车间调度算法

为了克服单独的遗传算法用于车间作业调度缺点,提出一种遗传算法与启发式算法结合的混合遗传算法,在运用该算法的过程中给出了适合的遗传操作和启发式规则的应用方法。结果表明：混合遗传算法优于两种单独的算法。     

A hybrid genetic and variable neighborhood descent algorithm for flexible job shop scheduling problems

This paper addresses the flexible job shop scheduling problem (fJSP) with three objectives: min makespan, min maximal machine workload and min total workload. We developed a hybrid genetic algorithm (GA) for the problem. The GA uses two vectors to represent solutions. Advanced crossover and mutation operators are used to adapt to the special chromosome structure and the characteristics of the problem. In order to strengthen the search ability, individuals of GA are first improved by a variable neighborhood descent (VND), which involves two local search procedures: local search of moving one operation and local search of moving two operations. Moving an operation is to delete the operation, find an assignable time interval for it, and allocate it in the assignable interval. We developed an efficient method to find assignable time intervals for the deleted operations based on the concept of earliest and latest event time. The local optima of moving one operation are further improved by moving two operations simultaneously. An extensive computational study on 181 benchmark problems shows the performance of our approach.     

A new hybrid parallel genetic algorithm for the job‐shop scheduling problem

The job‐shop scheduling problem (JSSP) is considered one of the most difficult NP‐hard problems. Numerous studies in the past have shown that as exact methods for the problem solution are intractable, even for small problem sizes, efficient heuristic algorithms must achieve a good balance between the well‐known themes of exploitation and exploration of the vast search space. In this paper, we propose a new hybrid parallel genetic algorithm with specialized crossover and mutation operators utilizing path‐relinking concepts from combinatorial optimization approaches and tabu search in particular. The new scheme relies also on the recently introduced concepts of solution backbones for the JSSP in order to intensify the search in promising regions. We compare the resulting algorithm with a number of state‐of‐the‐art approaches for the JSSP on a number of well‐known test‐beds; the results indicate that our proposed genetic algorithm compares fairly well with some of the best‐performing genetic algorithms for the problem.     

An effective asexual genetic algorithm for solving the job shop scheduling problem

By using the notion of elite pool, this paper presents an effective asexual genetic algorithm for solving the job shop scheduling problem. Based on mutation operations, the algorithm selectively picks the solution with the highest quality from the pool and after its modification, it can replace the solution with the lowest quality with such a modified solution. The elite pool is initially filled with a number of non-delay schedules, and then, in each iteration, the best solution of the elite pool is removed and mutated in a biased fashion through running a limited tabu search procedure. A decision strategy which balances exploitation versus exploration determines (i) whether any intermediate solution along the run of tabu search should join the elite pool, and (ii) whether upon joining a new solution to the pool, the worst solution should leave the pool. The genetic algorithm procedure is repeated until either a time limit is reached or the elite pool becomes empty. The results of extensive computational experiments on the benchmark instances indicate that the success of the procedure significantly depends on the employed mechanism of updating the elite pool. In these experiments, the optimal value of the well-known 10 × 10 instance, ft10, is obtained in 0.06 s. Moreover, for larger problems, solutions with the precision of less than one percent from the best known solutions are achieved within several seconds.     

基于遗传和禁忌搜索算法求解车间调度优化问题

针对柔性生产环境下的车间调度问题,在考虑遗传算法早熟收敛问题和禁忌搜索法自适应优点的基础上,将遗传算法和禁忌搜索法结合起来,提出了基于遗传和禁忌搜索的混合动态优化调度算法,并用实例对该算法进行了仿真研究。结果表明,此算法有很好收敛精度,是可行的,并且能够在扰动发生后提供新的调度计划,与传统的调度算法相比较,体现了明显的优越性。     

A hybrid genetic algorithm for the job shop scheduling problems

The Job Shop Scheduling Problem (JSSP) is one of the most general and difficult of all traditional scheduling problems. The goal of this research is to develop an efficient scheduling method based on genetic algorithm to address JSSP. We design a scheduling method based on Single Genetic Algorithm (SGA) and Parallel Genetic Algorithm (PGA). In the scheduling method, the representation, which encodes the job number, is made to be always feasible, the initial population is generated through integrating representation and G&T algorithm, the new genetic operators and selection method are designed to better transmit the temporal relationships in the chromosome, and island model PGA are proposed. The scheduling methods based on genetic algorithm are tested on five standard benchmark JSSP. The results are compared with other proposed approaches. Compared to traditional genetic algorithm, the proposed approach yields significant improvement in solution quality. The superior results indicate the successful incorporation of a method to generate initial population into the genetic operators.     

双资源生产车间调度问题的研究

将遗传算法(GA)和模拟退火算法(SA)相结合研究了双资源生产车间的调度优化问题,该混合算法将机床设备和工人合理地分配给加工任务,使评价性能指标获得最优。通过与国内外学者的算法进行比较,本算法获得的生产周期最短,机床利用率和工人利用率都较高,并且在某些情况下,平均流动时间也较短。因此可以证明本算法具有一定的优越性。     

柔性作业调度的串并行模型对比与求解

作业处理中的柔性使得作业调度更为灵活,作业中操作的执行顺序满足拓扑排序是作业调度的前提。是否允许没有优先关系的操作在不同的机器上同时执行是区分串行和并行调度的条件。文中以共生进化算法求解一个复杂的作业调度模型为例,给出了算法实现串行调度和并行调度的具体区别,并给出了串行和并行调度的结果。结果表明,并行相对于串行对算法效率的提高与柔性大小相关,与作业的规模成反比。     

考虑工件移动时间的柔性作业车间调度问题研究

分析生产车间的实际生产状况,建立了考虑工件移动时间的柔性作业车间调度问题模型,该模型考虑了以往柔性作业车间调度问题模型所没有考虑的工件在加工机器间的移动时间,使柔性作业车间调度问题更贴近实际生产,让调度理论更具现实性。通过对已有的改进遗传算法的遗传操作进行重构,设计出有效求解考虑工件移动时间的柔性作业车间调度问题的改进遗传算法。最后对实际案例进行求解,得到调度甘特图和析取图,通过对甘特图和析取图的分析验证了所建考虑工件移动时间的柔性作业车间调度问题模型的可行性和有效性。     

Finding multiple solutions in job shop scheduling by niching genetic algorithms

The interest in multimodal optimization methods is increasing in the last years. The objective is to find multiple solutions that allow the expert to choose the solution that better adapts to the actual conditions. Niching methods extend genetic algorithms to domains that require the identification of multiple solutions. There are different niching genetic algorithms: sharing, clearing, crowding and sequential, etc. The aim of this study is to study the applicability and the behavior of several niching genetic algorithms in solving job shop scheduling problems, by establishing a criterion in the use of different methods according to the needs of the expert. We will experiment with different instances of this problem, analyzing the behavior of the algorithms from the efficacy and diversity points of view.     

基于新型帝国竞争算法的高维多目标柔性作业车间调度

针对高维多目标柔性作业车间调度问题(MaOFJSP),提出了一种新型帝国竞争算法(ICA)以同时最小化最大完成时间、最大拖期、最大机器负荷和总能耗,该算法采用新方法构建初始帝国使得大多数殖民国家分配数量相近的殖民地,引入殖民国家的同化,并应用新的革命策略和帝国竞争方法以获得高质量解.最后通过大量实验测试ICA新策略对其性能的影响并将ICA与其他算法对比,实验结果表明新型ICA在求解MaOFJSP方面具有较强的优势.