拆卸线平衡问题的改进细菌觅食优化算法

拆卸是产品回收过程中最重要的环节,拆卸过程高效与否直接影响产品的回收效率。为克服传统算法求解拆卸线平衡问题时性能不稳定的缺陷,在构建基于工作站利用率、负荷均衡,尽早拆卸有危害、高需求的零件,最小化拆卸成本等方面的拆卸线平衡问题多目标优化模型的基础上,提出一种改进的细菌觅食优化算法对问题求解。通过改进细菌的移动规则扩大搜索空间,引入全局信息共享策略增强算法收敛性能,定义了一种自适应驱散概率防止驱散操作中解的退化。在对不同规模算例的对比分析中,验证了该算法的有效性。     

基于蚁群优化算法的目标拆卸序列规划

为了能够以较高的效率求解出产品中目标零件的拆卸方案,基于产品中零件间的拆卸优先约束关系,提出并建立目标零件的拆卸层次信息图模型,将目标零件的拆卸序列规划问题转化为对该图模型中具备最优值的路径的搜索和寻优问题.同时,提出一种改进蚁群优化算法,以实现对目标零件拆卸层次信息图的构建和对拆卸方案的搜索与寻优.最后通过实例验证了该方法的可行性和计算效率.     

求解约束优化问题的自适应人工蜂群算法

针对约束优化问题，提出一种自适应人工蜂群算法。算法采用反学习初始化方法使初始种群均匀分布于搜索空间。为了平衡搜索过程中可行个体和不可行个体的数量，算法使用自适应选择策略。在跟随蜂阶段，采用最优引导搜索方程来增强算法的开采能力。通过对13个标准测试问题进行实验并与其他算法比较，发现自适应人工蜂群算法具有较强的寻优能力和较好的稳定性。     

目标驱动离散布谷鸟搜索算法的不完全拆卸线平衡多目标优化

针对拆卸需求零件和危害零件的不完全拆卸线平衡问题,构建了优化拆卸序列长度、工作站数目、空闲时间均衡指标和拆卸成本的多目标不完全拆卸线平衡模型;为适应问题的离散性、多目标、多约束特性,提出了一种基于Pareto解集的目标驱动离散布谷鸟搜索算法.该算法首先建立模型与鸟窝位置、鸟蛋属性的映射关系,以此制定莱维飞行操作、巢寄生操作的离散化规则;然后通过以目标为导向的驱动操作实现单目标深度优化与多目标协同优化;为获得分布性良好的拆卸方案,采用拥挤距离机制筛选外部档案中的非劣解.对不同规模的3个实例与19个基准算例进行实验,验证了该算法的有效性和优越性;以某打印机的不完全拆卸为例,采用文中模型和算法进行不完全拆卸线平衡多目标优化,为决策者提供了侧重点不同的9种拆卸方案.     

基于刺激-响应分工机制的人工蜂群算法

针对人工蜂群算法中探索与开采的不平衡以及由此导致的求解精度低、收敛速度慢等问题,提出一种基于刺激-响应分工机制的人工蜂群算法.将探索和开采看成两种不同的搜索任务,令蜜蜂在雇佣蜂阶段执行探索,在跟随蜂阶段执行开采.根据种群多样性设计搜索任务的环境刺激,利用搜索成功率设计蜜蜂个体的响应阈值.在刺激-响应分工机制下,蜜蜂在雇...     

工位数固定的U型拆卸线部分拆卸平衡问题

为提高工位数固定的U型拆卸线拆卸效率, 减少有害部件对操作人员的潜在威胁, 针对高价值零部件和有害零部件的拆卸需求, 本文提出了工位数固定的U型拆卸线部分拆卸平衡问题, 建立了以最小化节拍时间、高危工位数目和负载均衡为目标的优化模型, 并设计了改进的变邻域搜索算法进行求解. 在编码过程中提出一种基于零部件释放位置的选择策略, 以减少前继零部件拆卸顺序对编码的影响; 提出最小偏差二分法, 有效减少解码的迭代次数; 提出瓶颈挤压局部搜索策略, 用以优化节拍时间和均衡负载指标. 通过与其他算法对比, 结果表明改进的变邻域搜索算法求解具有优越性, 并且可实现对工位数固定的U型拆卸线部分拆卸平衡问题的高效求解.     

基于精英蜂群搜索策略的人工蜂群算法

针对人工蜂群(ABC)算法存在收敛速度慢、求解精度不高、容易陷入局部最优等问题,利用蜂群觅食过程中先由侦察蜂进行四处侦察食物,并利用蜂群搜索构建精英群体指导蜂群觅食寻优。据此,提出了一种模拟侦察蜂侦察觅食行为的基于精英蜂群搜索策略的连续优化算法。算法利用构建精英蜂群策略、改进侦察蜂搜索机制以及基于目标函数值选择寻优三个主要策略加强算法的搜索机制。数值实验表明,所提算法不仅寻优精度和寻优率非常高,且收敛速度快,并能适于高维空间的优化问题。     

基于IPSO混沌支持向量机的网络流量预测研究

针对传统混沌支持向量机参数寻优算法的不足,提出了一种改进的粒子群(IPSO)算法。该算法通过延长迭代的开始阶段和最后阶段的搜索时间,实现了算法的全局搜索与局部搜索能力之间的平衡,进而优化模型参数,建立了基于IPSO优化的混沌支持向量机预测模型。应用实例结果表明,该模型对网络流量预测是有效可行的,并具有较高的寻优效率、预测精度和较好的稳态性能。     

基于交叉-变异人工蜂群算法的微网优化调度

随着大规模可再生能源接入微网,其不确定性直接影响微网的优化调度.鉴于此,以微网的产能利润最大化为目标,构建微网日前产能调度的优化模型,其中对储能单元和需求响应负荷进行调度,对可再生能源产能预测的误差进行处理.考虑优化模型中包含的非线性特征,提出一种基于交叉和变异的人工蜂群算法以求解微网最优调度策略.所提出算法在雇佣蜂和观察蜂阶段,引入遗传算法中的交叉和变异操作对邻域搜索策略进行更新,以确保子代种群的多样性;在侦查蜂阶段,构建基于全局搜索的初始化机制,以提高算法搜索全局最优解的能力.仿真结果验证了所构建模型的有效性和算法的优越性.     

具有自适应趋向性和引导因子的人工蜂群算法

针对人工蜂群算法中存在的收敛速度慢、寻优精度低的问题,提出了一种改进的人工蜂群算法。该算法将自适应趋向性加入雇佣蜂的搜索方案中,同时在观察蜂的搜索方案中加入引导因子。通过雇佣蜂对优秀蜜源的动态趋向搜索以及观察蜂在引导因子引领下的协同搜索,显著提高了算法的局部搜索能力。基于八个标准测试函数的仿真结果表明,与基本人工蜂群算法相比,改进后的算法在寻优精度和收敛速度方面均有明显提升。     

Multi-objective partial parallel disassembly line balancing problem using hybrid group neighbourhood search algorithm

To reduce waste during disassembly production and improve disassembly efficiency, this study investigates a type of partial parallel disassembly line applicable for the simultaneous disassembly of different products. A multi-objective mathematical model for a partial parallel disassembly line balancing problem is built considering four optimisation goals, namely, the minimisation of the cycle time, number of workstations, idle index, and quantity of disassembly resources. In addition, a novel multi-objective hybrid group neighbourhood search algorithm is proposed. First, a certain set of neighbourhood individuals (from the current population of individuals) is generated via neighbourhood search mechanisms based on optimal embedding and exchange operations. Then, a Pareto filtering process is performed on a mixed population composed of the individuals of the current population and all neighbourhoods. Subsequently, the current population individuals are renewed based on the mixed population. To prevent the algorithm from falling into a local optimum and to enhance the algorithm’s global search performance, we conduct a local search strategy based on a simulated annealing operation on the newly generated population individuals. The effectiveness and superiority of the proposed algorithm are proven by solving two complete disassembly line balancing problems at different scales and a partial disassembly line balancing problem, and also by comparison with several algorithms investigated in existing literature. Finally, the proposed model and algorithm are applied to a partial parallel disassembly line designed for the simultaneous disassembly of two types of waste products in a household appliance disassembly enterprise. The results of the partial parallel disassembly line are compared with those of an initial single-product straight disassembly line, and the comparison results show that the solution results of the optimisation goals for the partial parallel disassembly line are more superior than those of the initial single-product straight disassembly line.     

Artificial bee colony algorithm for solving sequence-dependent disassembly line balancing problem

In this paper, we consider a sequence-dependent disassembly line balancing problem (SDDLBP) with multiple objectives that requires the assignment of disassembly tasks to a set of ordered disassembly workstations while satisfying the disassembly precedence constraints and optimizing the effectiveness of several measures. Since the complexity of SDDLBP increases with the number of parts of the product, an efficient methodology based on artificial bee colony (ABC) is proposed to solve the SDDLBP. ABC is an optimization technique which is inspired by the behavior of honey bees. The performance of the proposed algorithm was tested against six other algorithms. The results show that the proposed ABC algorithm performs well and is superior to the other six algorithms in terms of the objective values performance.     

A Pareto improved artificial fish swarm algorithm for solving a multi-objective fuzzy disassembly line balancing problem

To better reflect the uncertainty existing in the actual disassembly environment, the multi-objective disassembly line balancing problem with fuzzy disassembly times is investigated in this paper. First, a mathematical model of the multi-objective fuzzy disassembly line balancing problem (MFDLBP) is presented, in which task disassembly times are assumed as triangular fuzzy numbers (TFNs). Then a Pareto improved artificial fish swarm algorithm (IAFSA) is proposed to solve the problem. The proposed algorithm is inspired from the food searching behaviors of fish including prey, swarm and follow behaviors. An order crossover operator of the traditional genetic algorithm is employed in the prey stage. The Pareto optimal solutions filter mechanism is adopted to filter non-inferior solutions. The proposed model after the defuzzification is validated by the LINGO solver. And the validity and the superiority of the proposed algorithm are proved by comparing with a kind of hybrid discrete artificial bee colony (HDABC) algorithm using two test problems. Finally, the proposed algorithm is applied to a printer disassembly instance including 55 disassembly tasks, for which the computational results containing 12 non-inferior solutions further confirm the practicality of the proposed Pareto IAFSA in solving the MFDLBP.     

改进近邻人工蜂群算法求解柔性作业车间调度问题

为了更好地解决以最小化最大完工时间为目标的柔性作业车间调度问题,提出了一种改进的人工蜂群算法。首先,采用随机选择和反向学习策略来提高初始蜜源的质量。同时,设计了一种新颖的特征表示方式,用于计算蜜源之间的距离。在引领蜂阶段,通过引入交叉和变异策略来优化种群中的近距离蜜源。在探索蜂阶段,引入了六种变邻域方法,以扩大解空间的搜索范围。而在侦查蜂阶段,则根据蜜源的潜力值剔除局部最优个体。在15个数据集上进行了广泛实验,实验结果表明,该改进算法性能明显优于其他四种著名的群智能优化算法。该研究为解决柔性作业车间调度问题提供了一种新的有效方法,对于实际生产调度具有重要的实用价值。     

A solution approach based on beam search algorithm for disassembly line balancing problem

The disassembly line balancing (DLB) problem is the process of allocating a set of disassembly tasks to an ordered sequence of workstations in such a way that optimizes some performance measures (e.g., cycle time, number of stations). Since DLB problems belong to the class of NP hard, many heuristic and meta-heuristic algorithms are applied to cope with the complexity of the DLB problems in order to obtain acceptable solutions in a reasonable amount of time. In this study, a beam search (BS) based approach for the DLB problem is proposed. Minimization of number of workstations is used as the performance measure. The proposed algorithm is compared with the optimal solutions of well-known real cases and generated test problems. The results indicate that the proposed approach based on BS is a very competitive and promising tool for further researches.     

A Pareto-discrete hummingbird algorithm for partial sequence-dependent disassembly line balancing problem considering tool requirements

To reduce the disassembly costs to enterprises and improve the disassembly efficiency of waste products, this study proposed a partial sequence-dependent disassembly line balancing problem (PSD-DLBP) and established a multi-objective mathematical model to simultaneously minimize the number of workstations, total disassembly time, idle balance index and the number of disassembly tools. Then, a Pareto-discrete hummingbird algorithm (PDHA) was proposed to address PSD-DLBP effectively. The PDHA includes two stages: self-searching stage and information-interacting stage. With these two stages, the exploration and exploitation abilities of PDHA can be balanced. Later, the effectiveness and superiority of the PDHA were verified by comparing it with the other four algorithms for two different-scale examples. Finally, the model and PDHA were applied to the optimization of a partial sequence-dependent disassembly line of waste laptops. The optimization results show that the partial disassembly can make the line smoother and the utilization efficiency of workstations higher than full disassembly, and PDHA is superior in solving the PSD-DLBP.     

模糊作业时间的拆卸线平衡Pareto多目标优化

针对实际拆卸作业的复杂性,建立了考虑模糊作业时间的多目标拆卸线平衡问题的数学模型,提出了一种基于Pareto解集的多目标遗传模拟退火算法进行求解。改进了模拟退火操作的Metropolis准则,使其能够求解多目标优化问题。采用拥挤距离评价非劣解的优劣,保留了优秀个体,并通过精英选择策略,将非劣解作为遗传操作的个体,引导算法向最优方向收敛。基于25项拆卸任务算例,通过与现有的单目标人工蜂群算法进行对比,验证了所提算法的有效性和优越性。最后将该算法应用于某打印机拆卸线实例中,求得8种可选平衡方案,实现了求解结果的多样性。     

Mixed model U-line balancing type-1 problem: A new approach

Avoiding work overload (imbalance) in mixed model U-line production systems entails an investigation into both balancing and sequencing problems at the same time and that is why some authors have considered both planning problems simultaneously. However because of the existing differences between planning horizons of balancing and sequencing problems (the former is a long to mid-term planning problem whereas the latter has a short term planning horizon) this simultaneous approach is only practical under very special conditions. It is also known that installation of an assembly line usually needs considerable capital investments and consequently it is necessary to design and balance such a system so that it works as efficiently as possible. To do so, in this paper, we develop a new approach to balance a mixed model U-shaped production system independent of what product sequences may be. This new approach is based on minimization of crossover workstations. Due to utilization of crossover workstations, balancing mixed model assembly lines in U-shaped line layouts is more complicated than that of straight lines. Some kind of issues including the ‘model mixes’ appearing in such workstations and the time taken for an operator to move from one side of the line to another increase the complexity of mixed model U-line balancing problems (MMULBP). Therefore it seems reasonable to develop a model in which minimizing the number of crossover workstations and maximizing the line efficiency are considered at the same time. Such a model is presented in this paper. In the proposed model, minimizing the variation of workload is also considered and taking into account operator's travel times, an extra time is assigned to workload of crossover workstations. Furthermore a genetic algorithm (GA) is proposed and a number of well-known test problems are solved by the GA and the related results are illustrated. Finally, the conclusion is presented.     

Lexicographic bottleneck mixed-model assembly line balancing problem: Artificial bee colony and tabu search approaches with optimised parameters

The lexicographic bottleneck assembly line balancing problem is a recently introduced problem which aims at obtaining a smooth workload distribution among workstations. This is achieved hierarchically. The workload of the most heavily loaded workstation is minimised, followed by the workload of the second most heavily loaded workstation and so on. This study contributes to knowledge by examining the application of the lexicographic bottleneck objective on mixed-model lines, where more than one product model is produced in an inter-mixed sequence. The main characteristics of the lexicographic bottleneck mixed-model assembly line balancing problem are described with numerical examples. Another contribution of the study is the methodology used to deal with the complex structure of the problem. Two effective meta-heuristic approaches, namely artificial bee colony and tabu search, are proposed. The parameters of the proposed meta-heuristics are optimised using response surface methodology, which is a well-known design of experiments technique, as a unique contribution to the expert and intelligent systems literature. Different from the common tendency in the literature (which aims to optimise one parameter at a time), all parameters are optimised simultaneously. Therefore, it is shown how a complex production planning problem can be solved using sophisticated artificial intelligence techniques with optimised parameters. The methodology used for parameter setting can be applied to other metaheuristics for solving complex problems in practice. The performances of both algorithms are assessed using well-known test problems and it is observed that both algorithms find promising solutions. Artificial bee colony algorithm outperforms tabu search in minimising the number of workstations while tabu search shows a better performance in minimising the value of lexicographic bottleneck objective function.