缓冲区容量约束下发动机混流装配线排序研究

为解决缓冲区容量约束下发动机混流装配排序问题,以关键部件消耗均匀化和最大完工时间最小化为目标,建立了优化数学模型,设计了一种多目标遗传算法,采用了混合交叉算子和启发式变异方法,并设计了基于帕累托分级和共享函数的适应度函数,将多目标遗传算法和多目标模拟退火算法的优化结果进行了比较。研究结果表明,多目标遗传算法在满意度和计算效率方面均优于多目标模拟退火算法,是一种有效的混流装配线排序问题求解算法。     

混合粒子群算法在混流装配线优化调度中的应用

应用粒子群算法求解混流装配线的优化调度问题,给出粒子的构造方法,并针对算法中存在过早收敛的问题,提出了一种与局部优化和粒子微变异方法相结合的混合粒子群算法.给出了一个实例,实例应用粒子群算法和混合粒子群算法分别进行求解,与其他一些方法比较表明,混合粒子群算法可以有效、快速地求得混流装配线优化调度问题的解.     

面向产品族的混流装配线平衡研究

基于产品族的模块化与通用性,研究了面向产品族装配的混流线平衡问题.基于对一族产品装配过程的聚类分析,提出了面向产品族的混流装配线的平衡设计方法和模型,可以为大规模定制企业实现面向产品族的混流装配提供参考,并用案例说明本文方法的应用.     

基于eM-Plant对注塑企业的生产线建模仿真

分析了注塑企业生产流程,并建立其生产工序的数学模型和仿真程序。根据企业的订单数量、车间生产线的规模等因素,通过对生产过程中批量的控制,研究批量和在制品库存水平的关系,提出了通过控制批量实现控制在制品的数学关系。     

Integrated Production Planning and Scheduling on Automobile Assembly Lines

We address the closely related problems of production planning and scheduling on mixed model automobile assembly lines. We propose an integrated solution, in which a production plan that is feasible with respect to aggregate capacity constraints is developed and then a sequence that is feasible with respect to this plan is sought. We propose three tabu-search-based algorithms that explore the solution spaces for both problems to different degrees to find a combination of a production plan and schedule that are feasible and that approximately optimize the objective function (involving the overproduction and underproduction of finished automobiles, the set-up cost, the idle times of work-cells on the line, the makespan and the load deviations among work-cells). Simulation is used to evaluate alternative schedules. Stochastic extensions are proposed and the complexities of these algorithms are discussed. Example runs comparing the algorithms are presented for deterministic cases, stochastic cases, types of automobiles, buffer sizes and number of work-cells. The results show that an embedded tabu search algorithm is suitable for solving small scale problems, an alternate tabu search algorithm for the medium scale and a serial tabu search algorithm for the large scale.     

Integral Manufacturing of Composite Skin-Stringer Assembly and Their Stability Analyses

Stiffened composite constructions are increasingly being used in the primary structures of aircraft. One key component in these structures is the assembly between the skin and the stringer. The purpose of the stringers sandwiched between two separate layers of skin is to provide structural integrity to a relatively weak skin-structure. Current practice is to fabricate the skin and the stringer separately, assemble them with adhesively bonded joints, and then co-cure the entire assembly in an autoclave. However, the reliability of the joint manufactured in this fashion is not dependable and hence requires riveting of the skin with the stringer by hundreds of mechanical fasteners. Although the mechanical fastener improves the joint reliability, it certainly increases the weight and reduces the strength of the structure by introducing stress concentration points around the rivet holes. In order to eliminate these disadvantages, an innovative low cost manufacturing technique has been developed. The technique utilizes the vacuum assisted resin transfer molding (VARTM) process to co-inject both the skin and the stringer in one integral step. Furthermore, the skin and the stringer are now part of one continuous fabric preform which by default eliminates any adhesive bonding. Several skin-stringer assemblies with plain weave carbon fabric and SC-15 epoxy resin have been manufactured following this procedure. Stability of the manufactured skin-stringer assembly has been investigated experimentally. The extensive analysis focused on the determination of the critical load corresponding to the instability of the structure, failure load and study of the failure mechanisms. Details of manufacturing procedures and experimental investigations are presented in the paper.     

插口组装线的产能分析和平衡改善

基于生产线平衡原理和基础工业工程(IE)手法,以作业测定为依据研究插口组装线的产能和平衡状况,针对产能过剩工序和瓶颈工序,分析工艺流程及操作,提出了持续改善方案.并对改善结果进行分析,在减少了一道工序的基础上使产能满足需求,平衡率达到预期目的.     

Selection of Item Response Model by Genetic Algorithm

A method of selecting an item response model with a genetic algorithm is proposed, where a model indicator variable is regarded as a chromosome to distinguish other individuals. This scheme enables a model for each item to be selected automatically. The genetic algorithm with the set of techniques that is implemented here is called the simple genetic algorithm, and the results obtained from simulation studies were satisfactory. An issue with the graded response model and the generalized partial credit model was examined using simulation studies and numerical examples was to find which was the more useful of these two prevailing kinds. The results obtained from simulation studies proved the graded response model fit the data more flexibly, since it fit the data generated under the generalized partial credit model more frequently than for the opposite case. However, the generalized partial credit model was more suitable for two real data sets.

     

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。     

An Analysis of Automated Storage and Retrieval Systems in Manufacturing Assembly Lines

An automated storage/retrieval system is a material handling system that can be used to pick and to deliver materials in a direct access fashion. An M/G/1 queueing model is used to study the system performance under a first-come-first-served dispatching rule. More detailed studies for different dispatching rules have been done by simulation. A number of cases with different hardware characteristics and workloads have been investigated. Conclusion is drawn based upon the results obtained from analysis as well as numerical experiments.     

Allocation of Buffer Capacities for a Class of Fixed Cycle Production Lines

The sequential relay model of a fixed cycle production: line is considered in which integer buffer capacities can be allocated between each pair of adjacent production facilities. The feasible sizes of any set of allocations is constrained by a general system of linear constraints. Upper and lower bounds are established for the steady-state system output and certain concave, separable programs are formulated to determine buffer capacities. The result of the optimization process is integrated into a simulation model for comparison and evaluation.     

Balancing Single Model Assembly Lines: Comments on A Paper by E. M. Dar-El (Mansoor)

In this brief note, we comment upon a statement made by E. M. Dar-El on the “computational impracticality” of a precedence matrix, enumeration method for balancing assembly lines,and show through an examination of several randomly generated, large problems, that the technique involved may indeed be quite effective in balancing assembly lines involving numerous individual work elements in a reasonable amount of computation time.     

Minimizing Makespan on Mixed Mass Production Lines of Two and Three Machines

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定频变温下粘弹材料动力学特性数据拟合分析

本文研究了粘弹性阻尼材料的耗能机理和动态阻尼特性,采用分数导数模型,并与温频等效原理相结合,得到了粘弹性阻尼材料的复模量、损耗因子与温度关系的参数化数学模型;并结合粘弹性阻尼材料的DMA测试实验数据对模型参量进行了拟合。实验结果和误差分析表明拟合的数学模型能够准确反映粘弹性材料在定频率变温度条件下的动力学特性的变化情况。     

基于装配相似性与灰色模型的汽车装配工时预测

汽车企业为适应市场需求的不断变化,加快了推出新车型产品的步伐。针对目前汽车总装混流工时预测速度缓慢的问题,提出基于装配相似性与灰色理论GM（0,N）模型的装配工时预测方法。将装配工时按特性分为取料时间、定位时间和连接时间,提取影响各部分工时的关键因素,通过计算样本与基准零件的装配相似系数,结合装配工时在MATLAB中构建拟合曲线,最后在函数关系式和GM（0,N）模型中分别预测定位时间和连接时间。通过与MTM法进行比较,证实该方法具有准确性和高效性。     

虚拟企业CRM系统的原型分析和设计

描述了虚拟企业CRM（客户关系管理）系统的特点，分析了虚拟企业CRM的信息流，在此基础上给出了一个分布式的虚拟企业CRM运作系统，其必须由虚拟企业CRM的协调企业统一管理和协调，并构造了虚拟企业CRM系统中的协调企业的功能模块参考结构，提出了实现虚拟企业CRM的技术体系参考模型。     

混合装配线防错系统的研究与开发

提出了面向复杂机械产品混合装配线的多Agent防错系统的模型,进行了相应的适应混合流水装配线的软硬件系统结构的研究。采用RS485总线控制系统的硬件配置,建立了工作站节点、数据采集、数据集成接口、智能决策等多Agent软件模块,形成了可适应装配产品变换的具有一定柔性、可扩展配置的防错系统。     

An Item Response Model for Multidimensional Analysis of Multiple-Choice Data

An item response model, similar to that in test theory, was proposed for multiple-choice questionaire data. In this model both subjects and item categories are represented as points in a multidimensional euclidean space. The probability of a particular subject choosing a particular item category is stated as a decreasing function of the distance between the subject point and the item category point. The subject point is assumed to follow a certain distribution, and is then integrated out to derive marginal probabilities of response patterns. A marginal maximum likelihood (MML) method was developed to estimate coordinates of the item category points as well as distributional properties of the subject point. Bock and Aitkin’s EM algorithm was adapted to the MML estimation of the proposed model. Examples were given to illustrate the method, which we call MAXMC.

     

TECHNICAL NOTE: Dynamic Manning of Long Cycle Assembly Lines With Learning Effect

This paper presents a model to design assembly lines which require long cycle times and complete relatively few products. Work-force requirements in such lines are dynamic in nature, since due to learning, worker's performance time is a decreasing function of the number of units already being assembled.

Instead of balancing the cycle time at all stages, the model permits the cycle time to decrease in time. An iterative linear programming approach is used to minimize total cost, including labor cost, hiring and lay off by varying the cycle time of the line.     

型号工程计量保证项目效益评估

针对号计量保证评估问题，用模糊数学的方法建立模糊综合评价模型，使定性评价变为定量分析，达到直观评价计量保证项目效益的目的。