免疫粒子群算法在混流装配线排序中的应用

混流装配线上的产品投产排序是影响装配线生产效率的重要因素.建立以最小化装配线总闲置—超载成本为优化目标的装配线排序模型,采用粒子群算法来解决混流装配线的投产排序问题.考虑到基本粒子群算法易陷入局部最优解的问题,引入免疫算法思想对其进行改进,根据抗体亲和性与浓度值的计算,及时进行粒子的替换以维持种群的多样性,防止粒子过早...     

工作研究在双边装配线平衡中的应用

针对双边装配线上某些工作站之间表面上看起来不存在等待与空闲时间,而实际上因操作方位及优先约束关系的限制存在大量的等待时间的现象,运用"5W1H"分析技术和"ECRS"四大原则,结合装配线平衡理论,对装配线的瓶颈工段进行改善,并重新布置装配线.新方案的实施使产线平衡率提高19.1%.     

应用SIMOGRAMS方法解决装配生产线瓶颈

详细介绍了SIMOGRAMS,一种新的人机操作分析、联合操作分析的新方法.针对某轮胎公司现有生产能力无法满足市场需求的实际问题,首先确定瓶颈车间-成型车间,然后运用SIMOGRAMS工具,从该车间装配生产的主要产品装配流程入手,对整个装配过程进行联合操作分析,提出了初步改善方案并分析改善效果.最后将装配线从固定式布置改变为产品式布置,根据各基本工作单元所包含的工作量将其组合成工作量基本相等的工作包,并将这些工作包分派给每个操作者或工作站,形成基于几种产品的细胞单元,大幅度提高了手工装配线的生产能力和灵活性.     

基于车型相似度的装配线排序

通过总结混流装配线排序问题,提出了一种新的装配线排序模型.根据装配车型的关键件不同,引入车型相似度的概念,应用遗传算法解决以最大化相似度总和为目标的混流装配线优化排序问题.经实践中应用,关键件装配更换次数减少了70%.     

基于eM-Plant软件的液压支架装配线物流仿真与优化

以eM-Plant软件为平台,对混流装配线进行仿真建模.在某液压支架项目建成之前,对订单所包含的产品种类、型号规格、需求数量、交货期及物流配送情况进行仿真,并合理优化小车数量、速度和装载量等参数.认为AGV小车为5台,运行速度为1.2m/s,运载量为20件的方案较优.     

基于仿真优化方法的混合装配线平衡

针对混合装配线平衡问题传统求解方法的局限性,提出采用仿真优化方法求解该问题。基于最小化工作站和仿真优化方法,分别建立以均匀化各个工作站平均负荷和瞬时负荷为目标的数学模型和仿真模型,并设计了遗传算法作为优化算法。根据仿真优化的原理构建了仿真优化系统并针对系统运行费时的特点,提出了相应的改进方法。通过实际例子验证了方法的可行性。     

遗传禁忌搜索算法在混流装配线排序中的应用

针对混流装配线排序问题，提出了一种混合遗传禁忌搜索算法，在每一代遗传演化之后，按一定比例随机选择部分解进行禁总搜索，以提高算法的全局搜索能力和收敛性。通过一个混流装配线排序实验，分别利用遗传算法和遗传禁忌搜索算法进行求解，结果表明遗传禁忌搜索算法具有更好的全局搜索能力和收敛性能。     

混流汽车液压电子制动控制单元装配线平衡问题设计与研究

为了有效解决混流汽车液压电子制动控制单元装配线平衡问题,提出了基于优化遗传算法的求解方法。首先对于复杂的液压电子制动控制单元装配线的工艺装配过程进行设计与计算,分析液压电子制动控制单元的生产工艺步序、工作站数、生产节拍、以最小化生产节拍、最小化工作站数以及均衡各工作站的加权平均负荷进行多目标优化。同时构建液压制动控制单元装配工艺平衡问题的测量模型,并进行案例分析,利用模型求解。最后,以某独资汽车零部件工厂的汽车液压电子制动控制单元装配线为例,对工艺过程进行数学建模,采用优化遗传算法进行求解。结果表明,所提方法与测量模型可为汽车液压电子制动控制单元装配线平衡问题提供可行的解决方案。     

装配线仿真流程及其案例研究

针对目前装配线仿真研究缺少模型检验步骤而导致仿真结果不可信的问题,在总结目前装配线仿真研究的基础上,引入两次仿真模型有效性的检验过程,提出完整的装配线仿真流程。为验证该流程的有效性,以实际装配线为例,在分析布局与工艺流程的基础上,考虑物流线布局、瓶颈机器数量、AGV数量和AGV速度对产能的影响,设计并基于Plant Simulation软件建立24种方案。所有方案仿真模型有效性的检验通过后,通过比较各方案的产能与机器利用率得到最佳方案。仿真结果表明,优化后的产能较初始方案提升约227%,瓶颈机器利用率提升约51%,平均机器利用率提升约121%。所提仿真优化流程可行且有效,可为装配线仿真研究与应用提供指导,对其他生产领域的仿真研究也具有借鉴意义。     

工作研究在生产装配线优化设计的应用

运用工作研究的程序分析、操作分析和动作分析方法,对某公司电能表的生产装配线流程和节拍进行了详细的测定与分析,对有关瓶颈工序、不规则操作和不合理的动作等问题提出了改进优化方案,并对改进前后的方案进行了对比分析,实践证明改进效果明显。     

Mixed model assembly system with multiple secondary feeder lines: layout design and balancing procedure for ATO environment

The constant research for efficiency and flexibility has forced assembly systems to change from simple/single assembly lines to mixed model assembly lines, while the necessity to reduce inventory has led the transition from single to multi-line systems, where some components are assembled in secondary lines, called feeder lines, connected to the main one by a ‘pull philosophy’. A possible approach to configure such an assembly system is to balance the main line first and use the retrieved cycle time to balance each feeder line separately, which is a questionable solution, especially if operators can perform tasks on both the feeder and the main line. Moreover for its complexity the mixed model balancing problem is usually solved transforming it into a single model by creating a single ‘virtual average model’, representative of the whole production mix. The use of a virtual average model assumes that the processing times of some models are higher or lower than the cycle time, which creates overload/idle time at the stations. This approach, especially in complex multi line production systems, largely reduces the assembly line productivity and increases the buffers dimensions. This paper faces the mixed model assembly line balancing problem in the presence of multiple feeder lines, introducing an innovative integrated main-feeder lines balancing procedure in case of unpaced assembly systems. The proposed approach is compared with the classical one and validated through simulation and industrial applications.     

发动机装配线平衡方法研究

研究了发动机装配线进行线平衡的基本思想及线平衡的前期基础工作，参照Thomopoulos的平衡搜寻法，以某公司的发动机装配线为例，提出了一种对有约束单一型发动机装配线平衡较实用的搜寻方法，阐明了如何对线平衡效果进行评估等内容。     

Workers’ rest allowance and smoothing of the workload in assembly lines

Ergonomic aspects have a crucial role in manual assembly systems. They impact on the workers’ health, final product quality and productivity. For these reasons, there is the necessity to integrate them into the assembly line balancing phase as, whereas, only time and cost variables are considered. In this study, human energy expenditures are considered as ergonomic aspects and we integrate them, for the first time, into the assembly line balancing problem type 2 through the rest allowance evaluation. We consider as an objective function the minimization of the smoothness index. Firstly, a new optimal method based on mixed integer linear programming and a new linearization methodology are proposed. Then, a heuristic approach is introduced. To complete the study, a computational experimentation is presented to validate the mathematical model and to compare the methodologies proposed in terms of computational time, complexity and solution. Additionally, we provide a detailed analysis of the impact that rest allowance evaluation can have on productivity comparing the results obtained, taking into account the rest allowance integration before, during and after the assembly balancing process.     

A multi-decision genetic approach for workload balancing of mixed-model U-shaped assembly line systems

A mixed-model assembly line is a type of production line where a variety of product models similar in product characteristics are produced. As a consequence of introducing the just-in-time (JIT) production principle, it has been recognised that a U-shaped assembly line system offers several benefits over the traditional straight line system. This paper proposes a new evolutionary approach to deal with workload balancing problems in mixed-model U-shaped lines. The proposed method is based on the multi-decision of an amelioration structure to improve a variation of the workload. This paper considers both the traditional straight line system and the U-shaped assembly line, and is thus an unbiased examination of line efficiency. The performance criteria considered are the number of workstations (the line efficiency) and the variation of workload, simultaneously. The results of experiments enhanced the decision process during multi-model assembly line system production; thus, it is therefore suitable for the augmentation of line efficiency in workstation integration and simultaneously enhancement of the variation of the workload. A case study is examined as a validity check in collaboration with a manufacturing company.     

基于启发式算法的电控板装配线线平衡优化

为了解决人员配置不稳定而导致的工位作业负荷不平衡问题,以某电控板装配企业为对象,构建其电控板装配线生产模型和线平衡优化模型。在该优化模型中,将约束条件转化为启发式规则,改进模型的参数设置和处理过程,将该模型转化为可求解的启发式算法。以该企业某电控装配线为例,通过线平衡优化实验证明该模型有效提高产量和线平衡率,说明该模型是有效和实用的。     

装配线平衡系统研究与开发

装配线的平衡问题已有大量理论研究,但缺乏应用工具.为了消除该问题理论与实际应用之间的鸿沟,利用有效的算法,开发了一个装配线平衡的系统.简要介绍了装配线平衡问题及其求解算法,阐述了系统的功能及其实现过程.企业界的工程技术人员利用该系统可以有效地解决装配线平衡问题,从而提高装配线的生产效率.     

U-shaped assembly line balancing problem with genetic algorithm

This paper presents a multi-objective genetic algorithm (moGA) to solve the U-shaped assembly line balancing problem (UALBP). As a consequence of introducing the just-in-time (JIT) production principle, it has been recognized that U-shaped assembly line systems offer several benefits over the traditional straight line systems. We consider both the traditional straight line system and the U-shaped assembly line system, thus as an unbiased examination of line efficiency. The performance criteria considered are the number of workstations (the line efficiency) and the variation of workload. The results of experiments show that the proposed model produced as good or even better line efficiency of workstation integration and improved the variation of workload.     

Heuristic procedures for solving the general assembly line balancing problem with setups

The general assembly line balancing problem with setups (GALBPS) was recently defined in the literature. It adds sequence-dependent setup time considerations to the classical simple assembly line balancing problem (SALBP) as follows: whenever a task is assigned next to another at the same workstation, a setup time must be added to compute the global workstation time, thereby providing the task sequence inside each workstation. This paper proposes heuristic procedures, based on priority rules, for solving GALBPS, many of which are an improvement upon heuristic procedures published to date.     

Integrated procedure of balancing and sequencing for mixed-model assembly lines: a multi-objective evolutionary approach

A mixed-model assembly line is a type of production line which is used to assemble a variety of product models with a certain level of similarity in operational characteristics. This variety causes workload variance among other problems resulting in low efficiency and line stops. To cope with these problems, a hierarchical design procedure for line balancing and model sequencing is proposed. It is structured in terms of an amelioration procedure. On the basis of our evolutionary algorithm, a genetic encoding procedure entitled priority-based multi-chromosome (PMC) is proposed. It features a multi-functional chromosome and provides efficient representation of task assignment to workstations and model sequencing. The lean production perspective recognises the U-shape assembly line system as more advanced and beneficial compared to the traditional straight line system. To assure the effectiveness of the proposed procedure, both straight and U-shape assembly lines are examined under two major performance criteria, i.e., number of workstations (or line efficiency) as static criterion and variance of workload (line and models) as dynamic criterion. The results of simulation experiments suggest that the proposed procedure is an effective management tool of a mixed-model assembly line system.     

Stochastic assembly line balancing using beam search

This paper presents a beam search-based method for the stochastic assembly line balancing problem in U-lines. The proposed method minimizes total expected cost comprised of total labour cost and total expected incompletion cost. A beam search is an approximate branch and bound method that operates on a search tree. Even though beam search has been used in various problem domains, this is the first application to the assembly line balancing problem. The performance of the proposed method is measured on various test problems. The results of the computational experiments indicate that the average performance of the proposed method is better than the best-known heuristic in the literature for the traditional straight-line problem. Since the proposed method is the first heuristic for the stochastic U-type problem with the total expected cost criterion, we only report its results on the benchmark problems. Future research directions and the related bibliography are also provided in the paper.