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1.
为实现柔性工艺与车间调度集成优化,在考虑工件特征的加工工艺、次序及加工机器的柔性基础上,以最小化最大完工时间为优化目标,提出一种基于交叉变异的人工蜂群算法。该算法针对柔性工艺与车间调度集成问题的离散性特征,对工艺路线进行序列编码,工件调度采用基于工序的编码方式。通过工艺种群与调度种群的交叉变异操作,分别使采蜜蜂及观察蜂进行局部寻优,侦查蜂进行全局寻优,以此提高算法性能。在此基础上用两部分测试实例分别验证了集成研究的必要性及改进算法的有效性。  相似文献   

2.
Job shop scheduling problem is a typical NP-hard problem. To solve the job shop scheduling problem more effectively, some genetic operators were designed in this paper. In order to increase the diversity of the population, a mixed selection operator based on the fitness value and the concentration value was given. To make full use of the characteristics of the problem itself, new crossover operator based on the machine and mutation operator based on the critical path were specifically designed. To find the critical path, a new algorithm to find the critical path from schedule was presented. Furthermore, a local search operator was designed, which can improve the local search ability of GA greatly. Based on all these, a hybrid genetic algorithm was proposed and its convergence was proved. The computer simulations were made on a set of benchmark problems and the results demonstrated the effectiveness of the proposed algorithm.  相似文献   

3.
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。  相似文献   

4.
Job shop scheduling problem is a typical NP-hard problem. An inventory based two-objective job shop scheduling model was proposed in this paper, in which both the make-span (the total completion time) and the inventory capacity were as objectives and were optimized simultaneously. To solve the proposed model more effectively, some tailor made genetic operators were designed by making full use of the characteristics of the problem. Concretely, a new crossover operator based on the critical path was specifically designed. Furthermore, a local search operator was designed, which can improve the local search ability of GA greatly. Based on all these, a hybrid genetic algorithm was proposed. The computer simulations were made on a set of benchmark problems and the results demonstrated the effectiveness of the proposed algorithm.  相似文献   

5.
针对作业车间调度问题的特征,提出一种基于基因表达式的克隆选择算法。在这个方法中,采用基因表达式编程算法中的编码方式来表示调度方案,同时为了提出的方法具有更强的全局搜索能力,运用克隆选择算法作为搜索引擎。最后,验证提出的方法的有效性,对7组Benchmark实例进行测试。实验结果表明,基于基因表达式的克隆选择算法在求解作业车间调度问题中是非常有效的。  相似文献   

6.
基于混合遗传算法的车间调度问题的研究   总被引:7,自引:2,他引:5  
提出了在柔性生产环境下基于遗传算法与模拟退火算法混合的动态调度算法,充分发挥遗传算法良好的全局搜索能力和模拟退火算法有效避免陷入局部极小的特性,有很好的收敛精度,并且能够在扰动发生后提供新的调度计划;通过交叉,变异等遗传操作、得到目标的最佳或次优解,最后对算法进行了仿真研究,仿真结果表明该算法是可行的,与传统的调度算法相比,其优越性是明显的。  相似文献   

7.
In this paper, we present a particle swarm optimization for multi-objective job shop scheduling problem. The objective is to simultaneously minimize makespan and total tardiness of jobs. By constructing the corresponding relation between real vector and the chromosome obtained by using priority rule-based representation method, job shop scheduling is converted into a continuous optimization problem. We then design a Pareto archive particle swarm optimization, in which the global best position selection is combined with the crowding measure-based archive maintenance. The proposed algorithm is evaluated on a set of benchmark problems and the computational results show that the proposed particle swarm optimization is capable of producing a number of high-quality Pareto optimal scheduling plans.  相似文献   

8.
The dynamic online job shop scheduling problem (JSSP) is formulated based on the classical combinatorial optimization problem – JSSP with the assumption that new jobs continuously arrive at the job shop in a stochastic manner with the existence of unpredictable disturbances during the scheduling process. This problem is hard to solve due to its inherent uncertainty and complexity. This paper models this class of problem as a multi-objective problem and solves it by hybridizing the artificial intelligence method of artificial immune systems (AIS) and priority dispatching rules (PDRs). The immune network theory of AIS is applied to establish the idiotypic network model for priority dispatching rules to dynamically control the dispatching rule selection process for each operation under the dynamic environment. Based on the defined job shop situations, the dispatching rules that perform best under specific environment conditions are selected as antibodies, which are the key elements to construct the idiotypic network. Experiments are designed to demonstrate the efficiency and competitiveness of this model.  相似文献   

9.
This article studies a no-wait two-stage flexible flow shop scheduling problem with setup times aiming to minimize the total completion time. The problem is solved using an adaptive imperialist competitive algorithm (AICA) and genetic algorithm (GA). To test the performance of the proposed AICA and GA, the algorithms are compared with ant colony optimisation, known as an effective algorithm in the literature. The performance of the algorithms are evaluated by solving both small and large-scale problems. Their performance is evaluated in terms of relative percentage deviation. Finally the results of the study are discussed and conclusions and potential areas for further study are highlighted.  相似文献   

10.
柔性作业车间调度问题具有解集多样化与解空间复杂的特点,传统多目标优化算法求解时容易陷入局部最优且丢失解的多样性。在建立以最大完工时间、最大能耗、机器总负荷为优化目标的柔性作业车间调度模型的情况下,提出一种改进的非支配排序遗传算法(Improved Non-dominated Sorting Genetic Algorithm II, INSGA-II)求解该模型。INSGA-II算法先将随机式初始化与启发式初始化方法混合,提高种群多样性;然后对工序部分与机器部分采用针对性的交叉、变异策略,提高算法全局搜索能力;最后设计自适应的交叉、变异算子以兼顾算法的全局收敛与局部寻优能力。在mk01~mk07标准数据集上的实验结果显示INSGA-II算法有着更优的算法收敛性与解集多样性。  相似文献   

11.
为提升维修作业与现代战机的适应程度,对军用飞机维修作业调度模型构建与调度优化算法设计进行探讨。在沿用柔性作业车间调度问题的形式化描述构建维修作业调度模型的基础上,选取遗传算法对执行步骤进行设计,引入耦合算子重新调整工序排序部分染色体以避免染色体违背耦合约束无法解码的情况发生,并采用维修作业调度案例与Brandimarte测试数据验证多目标调度优化算法的适用性与优化性。维修作业调度模型构建与调度优化算法的探讨促进维修管理的精细化,为调度相关领域的深入研究拓宽思路。  相似文献   

12.
A static job shop scheduling problem (JSSP) is a class of JSSP which is a combinatorial optimization problem with the assumption of no disruptions and previously known knowledge about the jobs and machines. A new hybrid algorithm based on artificial immune systems (AIS) and particle swarm optimization (PSO) theory is proposed for this problem with the objective of makespan minimization. AIS is a metaheuristics inspired by the human immune system. Its two theories, namely, clonal selection and immune network theory, are integrated with PSO in this research. The clonal selection theory builds up the framework of the algorithm which consists of selection, cloning, hypermutation, memory cells extraction and receptor editing processes. Immune network theory increases the diversity of antibody set which represents the solution repertoire. To improve the antibody hypermutation process to accelerate the search procedure, a modified version of PSO is inserted. This proposed algorithm is tested on 25 benchmark problems of different sizes. The results demonstrate the effectiveness of the PSO algorithm and the specific memory cells extraction process which is one of the key features of AIS theory. By comparing with other popular approaches reported in existing literatures, this algorithm shows great competitiveness and potential, especially for small size problems in terms of computation time.  相似文献   

13.
基于遗传算法的作业车间调度优化求解方法   总被引:2,自引:0,他引:2  
针对 job shop调度问题 ,提出了一种遗传算法编码方法和解码方法。该方法根据问题的特点 ,采用一种按工序用不同编号进行的染色体编码方案 ,并采用矩阵解码方法。此编码与调度方案一一对应 ,并且该编码方案有多种交叉操作算子可用 ,无须专门设计算子。算例计算结果表明 ,该算法是有效的 ,适用于解决 job shop调度问题 ,通过比较 ,该遗传算法优化 job shop调度操作简单并且收敛速度快。  相似文献   

14.
On the Complexity of Non-preemptive Shop Scheduling with Two Jobs   总被引:1,自引:0,他引:1  
Tamás Kis 《Computing》2002,69(1):37-49
In this note, we investigate the time complexity of non-preemptive shop scheduling problems with two jobs. First we study mixed shop scheduling where one job has a fixed order of operations and the operations of the other job may be executed in arbitrary order. This problem is shown to be binary NP-complete with respect to all traditional optimality criteria even if distinct operations of the same job require different machines. Moreover, we devise a pseudo-polynomial time algorithm which solves the problem with respect to all non-decreasing objective functions. Finally, when the job with fixed order of operations may visit a machine more than once, the problem becomes unary NP-complete. Then we discuss shop scheduling with two jobs having chain-like routings. It is shown that the problem is unary NP-complete with respect to all traditional optimality criteria even if one of the jobs has fixed order of operations and the jobs cannot visit a machine twice. Received July 28, 2001; revised May 15, 2002 Published online: July 26, 2002  相似文献   

15.
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.  相似文献   

16.
为求解车间作业调度问题,提出一种基于个体差异化自学习的改进教学算法.针对教学算法局部搜索能力不高的缺陷, 提出学生不仅应向能力好的学习者学习,亦应进行有差异的自我学习.通过学习者的完工时间评估学生的学习能力,提出学习次数概念,并设计自学习算子,完善学生阶段的更新,提高算法的局部搜索能力.最后,对OR-Library中的标准仿真实例进行实验,结果表明改进教学算法是有效的,其在收敛精度和鲁棒性能上均有较好的提高.  相似文献   

17.
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。  相似文献   

18.
As an extension of the classical job shop scheduling problem, flexible job shop scheduling problem (FJSP) is considered as a challenge in manufacturing systems for its complexity and flexibility. Meta-heuristic algorithms are shown effective in solving FJSP. However, the multiple critical paths issue, which has not been formally discussed in the existing literature, is discovered to be a primary obstacle for further optimization by meta-heuristics. In this paper, a hybrid Jaya algorithm integrated with Tabu search is proposed to solve FJSP for makespan minimization. Two Jaya operators are designed to improve solutions under a two-vector encoding scheme. During the local search phase, three approaches are proposed to deal with multiple critical paths and have been evaluated by experimental study and qualitative analyses. An incremental parameter setting strategy and a makespan estimation method are employed to speed up the searching process. The proposed algorithm is compared with several state-of-the-art algorithms on three well-known FJSP benchmark sets. Extensive experimental results suggest its superiority in both optimality and stability. Additionally, a real world scheduling problem, including six instances with different scales, is applied to further prove its ability in handling large-scale scheduling problems.  相似文献   

19.
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。  相似文献   

20.
基于Hopfield神经网络的作业车间生产调度方法   总被引:24,自引:2,他引:22  
该文提出了基于Hopfield神经网络的作业车间生产调度的新方法.文中给出了作业车间生产调度问题(JSP)的约束条件及其换位矩阵表示,提出了新的包括所有约束条件的计算能量函数表达式,得到相应的作业车间调度问题的Hopfield神经网络结构与权值解析表达式,并提出相应的Hopfield神经网络作业车间调度方法.为了避免Hopfield神经网络容易收敛到局部极小,从而产生非法调度解的缺点,将模拟退火算法应用于Hopfield神经网络求解,使Hopfield神经网络收敛到计算能量函数的最小值0,从而保证神经网络输出是一个可行调度方案.该文改进了已有文献中提出的作业调度问题的Hopfield神经网络方法,与已有算法相比,能够保证神经网络稳态输出为可行的作业车间调度方案.  相似文献   

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