猫群优化算法求解柔性作业车间调度问题

根据柔性作业车间的生产特点,对基本猫群优化算法进行设计和改进,提出了一种改进型猫群优化算法（Improved Cat Swarm Optimization,ICSO）,用于优化车间内工件的最大完工时间。算法给出了两段式个体位置编码方式和基于启发式算法的种群初始化策略;采用自适应行为模式选择方法,使其能够有效协调算法全局和局部搜索;提出了基于多样化搜寻算子的搜寻模式,增强算法的全局搜索能力;提出了基于莱维飞行的跟踪模式,增强算法的局部搜索能力。此外,算法中还引入了跳跃机制,使算法性能能够得到进一步的改善。实验数据表明ICSO算法在求解FJSP问题方面具有一定的有效性。     

混合灰狼优化算法求解柔性作业车间调度问题

将灰狼优化算法(GWO)用于柔性作业车间调度问题(FJSP),以优化最大完工时间为目标,提出一种混合灰狼优化算法(HGWO).首先,采用两段式编码方式,建立GWO连续空间与FJSP离散空间的映射关系;其次,设计种群初始化方法,保证算法初始解的质量;然后,嵌入一种变邻域搜索策略,加强算法的局部搜索能力,引入遗传算子,提升算法的全局探索能力;最后,通过实验数据验证HGWO算法在求解FJSP问题方面的有效性.     

改进的离散型萤火虫优化算法求解柔性作业车间调度问题

针对传统的群智能优化算法在求解柔性作业车间调度问题(FJSP)时,存在寻优能力不足且易陷入局部最优等缺点,本文以最小化最大完工时间为目标,将萤火虫算法(FA)用于求解柔性作业车间调度问题,提出一种改进的离散型萤火虫算法(DFA)。首先,通过两段式编码建立FA连续优化问题与FJSP离散优化问题之间的联系;其次,设计一种群初始化方法,以确保初始解的质量以及多样性;然后,提出改进离散型萤火虫优化算法并引入局部搜索算法,加强算法的全局搜索能力和局部搜索能力;最后,对标准算例进行仿真,验证DFA算法求解FJSP的有效性。通过与遗传算法和粒子群优化算法进行仿真对比,表明了DFA求解FJSP的优越性。     

基于改进量子猫群算法的流水车间调度研究

猫群算法（Cat Swarm Optimization,CSO）是近年来提出的一种新型群体智能算法,针对猫群算法在求解大规模调度问题中出现的不足,如易早熟、搜索效率低下等,提出了一种改进的量子猫群算法。将猫群算法的跟踪模式和搜寻模式中猫群位置的更新,通过基于量子旋转门的量子位概率幅更新的方式来实现,并提出了随时间可变的猫群模式选择配比MR。在求解流水线调度问题的仿真实验结果中表明,改进量子猫群算法的性能远远优于基本猫群算法。     

多目标粒子群优化算法在柔性车间调度中的应用

将粒子群优化(Particle Swarm Optimization,PSO)算法和混沌搜索方法结合在一起,提出一种求解多目标柔性作业车间调度问题(Flexible job shop scheduling problem,FJSP)的新算法,利用混沌对PSO的参数进行自适应优化来有效平衡算法的全局搜索和局部开挖能力,并采用混沌局部优化策略来改善算法的搜索性能.此外,为了搜索到问题的所有非劣解,采用基于模糊逻辑的适应度函数来评价粒子.对于四个典型FJSP实例的实验验证了算法的可行性和有效性.     

离散多种群入侵杂草优化算法求解柔性作业车间调度问题

针对柔性作业车间调度问题(FJSP)的特点,在基本入侵杂草优化算法原理的基础上,提出一种离散多种群入侵杂草优化算法.该算法引入多种群思想且在算法初期不进行种群交流,在各种群内采用交叉算子进行交流.当空间扩展时,采用自适应变异位数策略和领域搜索策略,提高了算法初期的全局搜索和后期的局部挖掘能力.在算法后期进行种群交流,提高了算法的收敛速度和寻优精度.将该算法用于柔性作业车间调度问题,且在解码时提出一种矩阵解码法.计算实例验证了所提出算法的有效性和优越性.     

区间数可重入混合流水车间调度与预维护协同优化

针对加工时间不确定的可重入混合流水车间调度与预维护协同优化问题,构建以区间最大完工时间、区间总碳排放和区间总预维护费用为优化目标的集成调度模型.针对问题特性,通过设计改进的可能度计算方法,定义区间意义下解的Pareto占优关系.提出一种改进的离散鲸鱼群算法,通过同步调度与维护策略,实现制造与维护的联合优化;设计个体间距离计算策略,寻找“最近较优个体”;设计个体位置移动策略以及多邻域搜索策略,有效地平衡全局搜索和局部搜索,提高收敛精度.通过大量的仿真实验和结果对比分析,表明了所提出的算法对于求解区间数可重入混合流水车间调度和预维护协同优化问题的有效性和可行性.     

基于新型蛙跳算法的低碳柔性作业车间调度

针对低碳柔性作业车间调度问题(flexible job shop scheduling problem,FJSP),提出一种新型蛙跳算法(shuffled frog leaping algorithm,SFLA)以总碳排放最小化,该算法运用记忆保留搜索所得一定数量的最优解,并采取基于种群和记忆的种群划分方法,应用新的搜索策略如全局搜索与局部搜索的协调优化以实现模因组内的搜索,取消种群重组使算法得到简化.采用混合遗传算法和教–学优化算法作为对比算法,大量仿真对比实验验证了SFLA对于求解低碳FJSP具有较强的搜索能力和竞争力.     

一种改进的求解柔性作业车间调度问题的灰狼算法

柔性作业车间调度问题是智能制造领域的一类典型调度问题,它是制造流程规划和管理中最关键的环节之一,有效的求解方法对提高生产效率具有重要的现实意义。本文基于经典灰狼算法进行改进,以优化最大完工时间为目标,提出一种改进的灰狼算法来求解柔性作业车间调度问题。算法首先采用基于权值的编码形式,实现对经典狼群算法中连续性编码的离散化;其次在迭代优化过程中加入随机游走策略,以增强局部搜索能力;然后在种群更新过程中加入尾部淘汰策略,在避免局部优化的同时增加种群多样性,合理扩大算法的广度搜索范围。在标准算例上的仿真实验结果表明,改进的灰狼算法在求解FJSP时比经典灰狼算法在寻优能力方面具有明显的优势,相比其它智能优化算法,本文所提算法在每种算例上均具有更好的优化性能。     

一种动态双种群果蝇优化算法求解FJSP

为了有效解决柔性作业车间调度问题(FJSP),提出了一种具有较强进化机制的动态双种群果蝇优化算法(DDFOA),该算法采用自适应移动步长,并动态地将种群划分为先进子种群和后进子种群,其中先进子种群侧重局部搜索,后进子种群负责全局搜索。同时针对柔性作业车间调度问题,设计了合适的编码转化方案。最后,对算法的收敛性进行了证明,并选用经典算例对其进行仿真实验,仿真结果验证了DDFOA求解FJSP的有效性。     

A hybrid harmony search algorithm for the flexible job shop scheduling problem

In this paper, a novel hybrid harmony search (HHS) algorithm based on the integrated approach, is proposed for solving the flexible job shop scheduling problem (FJSP) with the criterion to minimize makespan. First of all, to make the harmony search (HS) algorithm adaptive to the FJSP, the converting techniques are developed to convert the continuous harmony vector to a kind of discrete two-vector code for the FJSP. Secondly, the harmony vector is mapped into a feasible active schedule through effectively decoding the transformed two-vector code, which could largely reduce the search space. Thirdly, a resultful initialization scheme combining heuristic and random strategies is introduced to make the initial harmony memory (HM) occur with certain quality and diversity. Furthermore, a local search procedure is embedded in the HS algorithm to enhance the local exploitation ability, whereas HS is employed to perform exploration by evolving harmony vectors in the HM. To speed up the local search process, the improved neighborhood structure based on common critical operations is presented in detail. Empirical results on various benchmark instances validate the effectiveness and efficiency of our proposed algorithm. Our work also indicates that a well designed HS-based method is a competitive alternative for addressing the FJSP.     

Discrete harmony search algorithm for flexible job shop scheduling problem with multiple objectives

Flexible job-shop scheduling problem (FJSP) is a practically useful extension of the classical job shop scheduling problem. This paper proposes an effective discrete harmony search (DHS) algorithm to solve FJSP. The objectives are the weighted combination of two minimization criteria namely, the maximum of the completion time (Makespan) and the mean of earliness and tardiness. Firstly, we develop a new method for the initial machine assignment task. Some existing heuristics are also employed for initializing the harmony memory with discrete machine permutation for machine assignment and job permutation for operation sequencing. Secondly, we develop a new rule for the improvisation to produce a new harmony for FJSP incorporating machine assignment and operation sequencing. Thirdly, several local search methods are embedded to enhance the algorithm’s local exploitation ability. Finally, extensive computational experiments are carried out using well-known benchmark instances. Computational results and comparisons show the efficiency and effectiveness of the proposed DHS algorithm for solving the FJSP with weighted combination of two objectives.     

Flexible job shop scheduling using hybrid differential evolution algorithms

This paper proposes hybrid differential evolution (HDE) algorithms for solving the flexible job shop scheduling problem (FJSP) with the criterion to minimize the makespan. Firstly, a novel conversion mechanism is developed to make the differential evolution (DE) algorithm that works on the continuous domain adaptive to explore the problem space of the discrete FJSP. Secondly, a local search algorithm based on the critical path is embedded in the DE framework to balance the exploration and exploitation by enhancing the local searching ability. In addition, in the local search phase, the speed-up method to find an acceptable schedule within the neighborhood structure is presented to improve the efficiency of whole algorithms. Extensive computational results and comparisons show that the proposed algorithms are very competitive with the state of the art, some new best known solutions for well known benchmark instances have even been found.     

A hybrid Jaya algorithm for solving flexible job shop scheduling problem considering multiple critical paths

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.     

An effective hybrid particle swarm optimization algorithm for multi-objective flexible job-shop scheduling problem

Flexible job-shop scheduling problem (FJSP) is an extension of the classical job-shop scheduling problem. Although the traditional optimization algorithms could obtain preferable results in solving the mono-objective FJSP. However, they are very difficult to solve multi-objective FJSP very well. In this paper, a particle swarm optimization (PSO) algorithm and a tabu search (TS) algorithm are combined to solve the multi-objective FJSP with several conflicting and incommensurable objectives. PSO which integrates local search and global search scheme possesses high search efficiency. And, TS is a meta-heuristic which is designed for finding a near optimal solution of combinatorial optimization problems. Through reasonably hybridizing the two optimization algorithms, an effective hybrid approach for the multi-objective FJSP has been proposed. The computational results have proved that the proposed hybrid algorithm is an efficient and effective approach to solve the multi-objective FJSP, especially for the problems on a large scale.     

基于离散鸡群压缩感知的WSNs多目标定位

对无线传感器网络（WSNs）多目标定位问题进行研究,提出一种基于离散鸡群压缩感知的多目标定位方法。首先给出离散鸡群算法（DCSO）相关定义,设计离散鸡群编码方式和迭代进化策略,在此基础上,构建基于压缩感知（CS）的WSNs多目标定位模型,对测量矩阵和稀疏矩阵进行合理选取,并将离散鸡群算法应用于CS信号重构算法中,实现对稀疏度未知多目标位置信息的精确重构。仿真结果表明,与OMP和MLE定位算法相比,该方法具有较高的多目标定位精度。     

Bi-criteria flexible job-shop scheduling with sequence-dependent setup times—Variable neighborhood search approach

In scheduling problems, taking the sequence-dependent setup times into account is one of the important issues that have recently been considered by researchers in the production scheduling field. In this paper, we consider flexible job-shop scheduling problem (FJSP) with sequence-dependent setup times to minimize makespan and mean tardiness. The FJSP consists of two sub-problems from which the first one is to assign each operation to a machine out of a set of capable machines, and the second one deals with sequencing the assigned operations on all machines. To solve this problem, a variable neighborhood search (VNS) algorithm based on integrated approach is proposed. In the presented optimization method, the external loop controlled the stop condition of algorithm and the internal loop executed the search process. To search the solution space, the internal loop used two main search engines, i.e. shake and local search procedures. In addition, neighborhood structures related to the sequencing problem and the assignment problem were employed to generate neighboring solutions. To evaluate the performance of the proposed algorithm, 20 test problems in different sizes are randomly generated. Consequently, computational results and comparisons validate the quality of the proposed approach.