An efficient search method for multi-objective flexible job shop scheduling problems

Flexible job shop scheduling is very important in both fields of production management and combinatorial optimization. Owing to the high computational complexity, it is quite difficult to achieve an optimal solution to this problem with traditional optimization approaches. Motivated by some empirical knowledge, we propose an efficient search method for the multi-objective flexible job shop scheduling problems in this paper. Through the work presented in this work, we hope to move a step closer to the ultimate vision of an automated system for generating optimal or near-optimal production schedules. The final experimental results have shown that the proposed algorithm is a feasible and effective approach for the multi-objective flexible job shop scheduling problems.     

基于TSAPO的柔性作业车间计划和调度

为使多目标柔性作业车间计划与调度的制定更适合实际生产的动态变化,提出增加动态反馈的闭环柔性作业车间计划模型及二阶式蚁群粒子群混合优化算法TSAPO。通过增加动态监视功能,及时更新和反馈实际生产数据。利用对优化目标的二阶段分解,设计带有反馈机制的调度算法。实验结果证明,该算法在求解多目标柔性作业车间调度问题中具有较好的优化效果。     

求解区间柔性作业车间调度的多目标进化算法

针对不确定多目标柔性作业车间调度问题,将工序加工时间采用区间数表示,以区间最大完工时间和区间机器总负荷为优化目标,构建多目标区间柔性作业车间调度模型,并设计一种多目标进化优化算法对该模型进行求解.算法采用混合策略生成初始化种群,并采用贪婪插入法对染色体进行解码,通过基于可能度的占优关系评价个体性能,将区间目标归一化结合拥挤距离反映优化解的分布情况.实验结果验证了所提出算法的有效性.     

遗传算法求解多目标柔性Job-shop问题

本文描述了基于可变机器约束的多目标柔性Job-shop调度问题模型,并应用一种改进的遗传算法进行求解。我们采用了表示工序先后顺序及机器选择的二维编码方式,以多目标优化函数为度量,通过三种遗传操作扩展后代的多样性和算法的搜索空间。仿真结果验证了该算法能有效解决多目标优化问题。     

基于正态云模型的状态转移算法求解多目标柔性作业车间调度问题

为了求解具有多目标多约束的柔性作业车间调度问题,提出一种基于正态云模型的状态转移算法.构建以最小化最大完工时间、机器总负荷及瓶颈机器负荷为目标的多目标柔性作业车间调度问题的数学模型;针对灰熵关联度适应度分配策略在Pareto解比较序列与参考序列之间的差值相等时不能引导算法进化的情况,提出一种改进灰熵关联度的适应度值分配策略;同时引入兼具模糊性和随机性的云模型进化策略以改进状态转移算法,可有效避免算法早熟并增加候选解的多样性.仿真结果表明:基于正态云模型的状态转移算法能够有效解决多目标柔性作业车间调度问题;与其他算法相比,所提出算法求解问题的收敛精度更高、收敛速度更快.     

面向能耗机制的多目标柔性作业车间调度*

针对面向绿色制造的车间调度问题,考虑能源消耗、最大完工时间、生产成本等调度目标,建立了多目标柔性作业车间调度问题模型,并提出一种改进离散蝙蝠算法来求解。针对这个模型的特点,为了有效地表达出工序与粒子种群之间的关系,提出一种整数编码策略。为了避免粒子早熟收敛、求解精度低等问题,设计了一种具有记忆能力的粒子变异操作。为了克服基本蝙蝠算法固定参数不足的缺点,重新调整惯性权重的值,提出一种线性递减的惯性权重策略。针对具体生产实例进行验证,实验数据表明,该改进算法在求解多目标柔性作业车间调度问题上具有良好的性能,是一种有效的调度算法。     

Ant colony optimization for multi-objective flow shop scheduling problem

Flow shop scheduling problem consists of scheduling given jobs with same order at all machines. The job can be processed on at most one machine; meanwhile one machine can process at most one job. The most common objective for this problem is makespan. However, multi-objective approach for scheduling to reduce the total scheduling cost is important. Hence, in this study, we consider the flow shop scheduling problem with multi-objectives of makespan, total flow time and total machine idle time. Ant colony optimization (ACO) algorithm is proposed to solve this problem which is known as NP-hard type. The proposed algorithm is compared with solution performance obtained by the existing multi-objective heuristics. As a result, computational results show that proposed algorithm is more effective and better than other methods compared.     

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。     

基于混合人工蜂群算法的多目标柔性作业车间调度问题研究

传统的优化算法在求解面对多目标柔性作业车间调度时,往往求解效率低且难以获得最优解。为了求解多目标柔性作业车间调度问题,设计了混合人工蜂群算法。种群的初始化采用了多种方法相结合的策略。在人工蜂群算法的不同阶段采用不同的搜索机制,在雇佣蜂阶段采用开发搜索,针对跟随蜂阶段蜜蜂跟随的对象的优秀解进行小幅度的更新,从而提高了搜索的表现。禁忌搜索与改进的人工蜂群算法相结合,有效的提升了获得最优解的概率。通过相关文献中的标准实例对设计的混合人工蜂群算法进行一系列求解测试,实验的结果有效的说明了算法在求解柔性作业车间调度问题时效果显著。通过求解结果对比表明人工蜂群算法的高效性和优越性。     

遗传算法解柔性作业车间调度问题应用综述

柔性作业车间调度问题是典型的NP难问题,对实际生产应用具有指导作用。近年来,随着遗传算法的发展,利用遗传算法来解决柔性作业车间调度问题的思想和方法层出不穷。为了促进遗传算法求解柔性作业车间调度问题的进一步发展,阐述了柔性作业车间调度问题的研究理论,对已有改进方法进行了分类,通过对现存问题的分析,探讨了未来的发展方向。     

Two-generation Pareto ant colony algorithm for multi-objective job shop scheduling problem with alternative process plans and unrelated parallel machines

The flexibilities of alternative process plans and unrelated parallel machines are benefit for the optimization of the job shop scheduling problem, but meanwhile increase the complexity of the problem. This paper constructs the mathematical model for the multi-objective job shop scheduling problem with alternative process plans and unrelated parallel machines, splits the problem into two sub-problems, namely flexible processing route decision and task sorting, and proposes a two-generation (father and children) Pareto ant colony algorithm to generate a feasible scheduling solution. The father ant colony system solves the flexible processing route decision problem, which selects the most appropriate process node set from the alternative process node set. The children ant colony system solves the sorting problem of the process task set generated by the father ant colony system. The Pareto ant colony system constructs the applicable pheromone matrixes and heuristic information with respect to the sub-problems and objectives. And NSGAII is used as comparison whose genetic operators are re-defined. The experiment confirms the validation of the proposed algorithm. By comparing the result of the algorithm to NSGAII, we can see the proposed algorithm has a better performance.     

批量生产柔性作业车间多目标精细化调度方法

提出了一种批量生产柔性作业车间多目标精细化调度方法。针对批量生产柔性作业车间多目标调度问题特点,建立了一类以完工时间最短和制造成本最低为优化目标的等量分批柔性作业车间调度多目标优化模型。提出了5种批量生产柔性作业车间精细化调度技术;设计了一种改进的NSGA II算法对模型进行求解。算法中引入面向对象技术处理复杂的实体逻辑关系,使用矩阵编码技术进行编码,采用分段交叉和分段变异的遗传算子实现遗传进化,应用上述5种精细化调度技术于解码过程以提高设备利用率。通过案例分析验证了该方法的有效性。     

任务分解控制及人员柔性的车间集成调度

针对复杂产品制造环境下制造任务分解与资源配置脱节的问题,提出了制造任务分解与多目标人员柔性车间资源配置优化方法。在对复杂制造任务特点进行分析的基础上,建立了任务分解粒度控制模型和考虑人员柔性的制造单元资源模型,利用自适应非支配排序遗传算法进行求解,得到了较为满意的任务分解和车间资源调度方案。     

Multi-objective simulation optimization for uncertain resource assignment and job sequence in automated flexible job shop

In this study a multi-objective problem considering uncertainty and flexibility of job sequence in an automated flexible job shop (AFJS) is considered using manufacturing simulation. The AFJS production system is considered as a complex problem due to automatic elements requiring planning and optimization. Several solution approaches are proposed lately in different categories of meta-heuristics, combinatorial optimization and mathematically originated methods. This paper provides the metamodel using simulation optimization approach based on multi-objective efficiency. The proposed metamodel includes different general techniques and swarm intelligent technique to reach the optimum solution of uncertain resource assignment and job sequences in an AFJS. In order to show the efficiency and productivity of the proposed approach, various experimental scenarios are considered. Results show the optimal resources assignment and optimal job sequence which cause efficiency and productivity maximization. The makespan, number of late jobs, total flow time and total weighted flow time minimization have been resulted in an automated flexible job shop too.     

求解多目标作业车间调度问题的混合变异杂草优化算法

针对多目标作业车间调度问题,提出一种混合变异杂草优化算法。该算法采用基于各子目标熵值权重的欧氏贴近度作为适应度值计算方法,引导种群向Pareto前端进化。在进化过程中,运用快速非支配排序策略构建Pareto档案,并利用进化种群中最优个体实时更新Pareto最优解集,提升算法的优化性能;同时通过引入变异算子增加种群多样性,避免算法陷入局部最优。最后,基于Benchmark算例的仿真实验,验证了该算法求解多目标作业车间调度问题的有效性。     

考虑多目标的柔性工艺与调度集成优化算法

针对工艺规划与车间调度集成优化问题,在考虑零件的加工工序柔性、工序次序柔性及加工机器柔性的基础上,以最大完工时间、总加工成本和总拖期时间为优化目标,对多目标柔性工艺与车间调度集成问题建模,提出一种基于改进人工蜂群算法的多目标柔性工艺与车间调度集成优化策略,并提出邻域变异操作以及全局交叉操作,对种群进行更新。引入Pareto方法,通过对适应度评价、贪婪准则、Pareto最优解集构造和保存以及解得多样性维护等方面进行改进,设计了一种基于Pareto方法的多目标人工蜂群算法。最后,通过采用基本人工蜂群算法及改进人工蜂群算法对六个工件、五台机床的柔性工艺与车间调度集成问题进行优化,验证了改进算法的有效性。     

Discrepancy search for the flexible job shop scheduling problem

The flexible job shop scheduling problem (FJSP) is a generalization of the classical job shop problem in which each operation must be processed on a given machine chosen among a finite subset of candidate machines. The aim is to find an allocation for each operation and to define the sequence of operations on each machine, so that the resulting schedule has a minimal completion time. We propose a variant of the climbing discrepancy search approach for solving this problem. We also present various neighborhood structures related to assignment and sequencing problems. We report the results of extensive computational experiments carried out on well-known benchmarks for flexible job shop scheduling. The results demonstrate that the proposed approach outperforms the best-known algorithms for the FJSP on some types of benchmarks and remains comparable with them on other ones.     

基于改进的基因表达式编程算法在作业车间调度问题中的应用

文章提出一种新颖的方法一改进的基因表达式编程算法来求解作业车间调度问题。作业车间调度问题是许多实际生产调度问题的简化模型,基因表达式编程算法结合了遗传算法和遗传编程的优点,具有更强的解决问题能力,对基因表达式编程算法进行改进使其在作业车间调度问题的应用上更加有效;最后应用一个实例来验证提出方法的有效性。     

多目标柔性Job Shop调度问题的技术现状和发展趋势*

首先概述了多目标柔性Job Shop调度问题的基本概念,包括问题定义、常用假设条件、性能指标和问题的分类,讨论了其复杂性;其次,分别从建模、优化方法和原型系统研究方面综述了其发展过程和研究现状,对一类更加通用的多目标柔性Job Shop问题进行了简单的文献综述;最后指出了现有研究存在的问题与不足,并对未来的发展趋势进行了探讨。     

Group shops scheduling with makespan criterion subject to random release dates and processing times

This paper deals with a stochastic group shop scheduling problem. The group shop scheduling problem is a general formulation that includes the other shop scheduling problems such as the flow shop, the job shop and the open shop scheduling problems. Both the release date of each job and the processing time of each job on each machine are random variables with known distributions. The objective is to find a job schedule which minimizes the expected makespan. First, the problem is formulated in a form of stochastic programming and then a lower bound on the expected makespan is proposed which may be used as a measure for evaluating the performance of a solution without simulating. To solve the stochastic problem efficiently, a simulation optimization approach is developed that is a hybrid of an ant colony optimization algorithm and a heuristic algorithm to generate good solutions and a discrete event simulation model to evaluate the expected makespan. The proposed approach is tested on instances where the random variables are normally, exponentially or uniformly distributed and gives promising results.