面向产品配置的模块形成及划分方法

产品配置要考虑客户需求、模块组合复杂度、设计复杂度和成本,合理模块划分是产品配置基础。通过分析客户需求和零部件各相关性因素,建立零部件模糊相似性矩阵,并构建零部件模糊聚类树,描述模块的形成过程。提出采用复合λ对模糊聚类树截距,以组合复杂度、设计复杂度和成本为优化目标进行模块划分。利用遗传算法进行模块划分的优化,得到各λ值,进而得到模块划分的优化结果。此方法不仅考虑零部件之间相关的紧密程度,而且考虑模块划分的目的,以某天文圆顶为例说明了该方法的可行性和适用性。     

面向产品变型设计的模块划分方法

首先进行客户需求分析和功能分解,其次将功能映射到结构以确定结构元,通过对零部件功能和结构相关度分析,分别建立以下3个相关度矩阵——基于客户需求的零部件相关度矩阵、功能相关度矩阵和结构相关度矩阵,分配好各自的权重系数后,综合该3个矩阵建立综合相关度矩阵.由模糊聚类方法得到不同的划分方案.依据信息熵的思想,从面向产品变型设计的角度,提出以装配复杂度、客户参与变型设计复杂度、模块之间独立性与模块内部元素亲密度为优化目标,建立模块划分方案数学评价模型,从而得到较合理的划分方案.最后根据提出的3条调整准则对划分方案进行适当调整以符合实际需要.以电动双梁式桥式起重机中的桥架为例进行模块划分,验证划分方法.     

考虑两两模块之间关联关系的产品模块划分方法

针对产品模块化设计问题,考虑了零部件之间的非对称及两两模块之间关联关系,提出了一种产品模块划分方法。通过设计结构矩阵来表达产品零部件之间的关联关系,利用FCM算法对零部件进行聚类,分析了两两模块之间可能存在不同的依赖关系,以模块内聚度和模块间耦合度为目标,建立了模块度准则,从而得到合理的模块划分方案。最后以起重机吊钩组为实例说明了产品模块划分过程。     

面向维修性的地铁转向架轮对组成模块划分方法

地铁转向架轮对组成是影响列车安全运行的关键部件,由于其故障频次高、维修难度大,因此在设计时考虑其维修性至关重要。在对维修工艺和故障模式进行分析和指标量化的基础上,提出引入轮廓系数的K-Means维修模块聚类的方法,实现轮对组成面向维修性的模块划分。首先,根据各零部件的维修工艺和故障模式,分别确定其难易程度指标和故障间隔时间指标;其次,实现零部件面向维修性的聚类,并引入轮廓系数判别划分结果的合理性;最后根据地铁实际维修数据,实现轮对组成的维修模块划分并探讨相应的维修策略。     

批量客户化生产模式下的模块划分方法研究

在批量客户化生产模式下,不仅要考虑客户对产品的多品种小批量的功能需求,又要满足客户对产品的大批量生产的低成本的要求,合理有效的模块划分是解决上述矛盾的关键。在模糊聚类分析及信息熵理论的基础上,提出了考虑客户需求、产品的装配、成本和维修等综合因素的模块划分方法和策略,分析了模块聚类的相关准则和基于信息熵的量化评价方法,建立了相应的数学评价模型,并以电钻为例,利用提出的方法得出了用模块化方法进行产品再设计时模块划分的初始方案。     

一种面向产品族设计的模块动态规划方法

针对产品族设计中的模块规划问题,研究和分析了产品族核心系统的模块化理论和实施方法,对产品生命周期中的各种动态要素进行了分析;根据核心系统零部件成本等市场因素的动态变化对模块规划的影响,从可维护性和经济性考虑,提出一种产品族核心系统模块动态规划方法;通过建立功能关联矩阵和动态关联权重矩阵,采用模糊聚类方法对功能关联矩阵中的组件进行聚类,通过取适当的α截集,将产品族中的核心系统划分为多个子功能模块,结合动态关联权重分析对模块部件进行动态评价,并提取出动态评价值较高的部件,为设计阶段重点考虑这些部件提供了理论依据,减少了后期维护成本.通过装载机液压传动系统的模块规划和后期维护数据,证明了该方法的可行性.     

三维CAD模型模块划分的蚁群聚类图分割方法

为了使三维CAD模型模块划分的结果保持较好的结构完整性,提出一种面向图分割的蚁群聚类算法.用属性连接图表示复杂的CAD模型并进行简化;通过对模型连接方式和零件属性的分析,获得零件的结构、功能和材料相关性并建立综合相关度矩阵;根据零件的连接层次关系重构了蚁群聚类的局部范围界定和密度函数计算方法,实现了面向图分割的的蚁群聚类.采用上述方法对某型飞机襟翼模型进行模块划分,验证了所提方法的正确性和有效性.     

支持再制造升级的机械产品绿色模块划分方法研究

针对产品过时或淘汰造成的资源无法有效回收利用问题,对机械产品再制造升级的性能需求进行了研究,提出了一种基于设计结构矩阵的产品绿色模块划分方法.定义了产品零部件之间的功能、结构、回收模式等再制造升级的绿色属性;根据层次分析法计算得出了各属性的所占权重,在此基础上建立了产品零件的综合关联度矩阵;根据产品的设计需求、经济性和...     

多视角的特征关联模块划分方法

为了满足客户对产品的多样化需求,在模块划分过程中从产品的定制化需求、产品功能、产品结构和绿色度等多视角考虑,提出了一种多视角的特征关联模块划分方法.首先,分析客户的多样化需求,研究关于模块划分的各视角特征信息并建立其相应的特征模型与关联矩阵.其次,利用层次分析法分析不同视角在设计过程中所占有的重要程度,依据不同视角的重要程度进行特征的关联.然后建立综合特征关联矩阵,采用遗传算法进行求解.最后,以冲击电钻为实例,建立其相应的产品模型且应用遗传算法对其进行模块划分,验证所提多视角特征关联模块划分方法的有效性.     

考虑变更风险的复杂产品模块划分方法

模块化方法可有效控制复杂产品的研制周期与成本,模块划分是实现模块化的基础.受顾客需求、关键技术及政策、市场等内外部动态因素的影响,持续演化是复杂产品的必然趋势.设计变更是企业实现产品演化的基本手段,为了降低演化的影响,在对复杂产品进行模块划分时,同时考虑功能、结构、变更风险三个因素.首先将复杂网络理论应用于复杂产品结构建模,以零部件为节点,零部件的关联关系为边,建立复杂产品零部件网络模型.然后基于LinkRank的社区发现算法求解出产品模块初始划分方案.其次再利用基于网络相似度优化的社区发现算法得到最终划分方案.最后以某型号摩托车发动机为例验证了所提方法的可行性和有效性.     

面向主动再制造的产品模块化设计方法

针对面向主动再制造的产品模块化问题,提出了模块化设计流程,结合产品生命周期各阶段特性,从材料的选择与配置、再制造加工性能、使用与维护性、经济性、功能物理可行性等方面制订产品主动再制造模块划分准则。结合模糊动态聚类分析方法,构建产品零部件相似性矩阵,进行产品零部件模块划分,并基于模块内/模块间关联度分析,选取最优阈值,实现模块优化。最后以某款洗碗机产品为例,验证了该方法的有效性。     

面向产品创新设计的功能模块动态划分方法研究

针对面向产品创新设计的功能模块划分中没有考虑技术进化的问题,从客户需求、流、技术的角度出发,研究功能模块动态划分方法。以产品的功能结构为基础,建立了功能相关矩阵。基于模糊等价矩阵的动态聚类分析,动态划分产品的功能模块。以模块内平均聚合度和模块间平均分离度来评价不同模块划分结果。多绳金刚石串珠锯功能模块动态划分实例说明了该方法具有较强的分辨性,可以进行面向产品创新设计的功能模块动态划分。
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Disassemblability Modeling Technology of Configurable Product Based on Disassembly Constraint Relation Weighted Design Structure Matrix（DSM）

The current research of configurable product disassemblability focuses on disassemblability evaluation and disassembly sequence planning. Little work has been done on quantitative analysis of configurable product disassemblability. The disassemblability modeling technology for configurable product based on disassembly constraint relation weighted design structure matrix （DSM） is proposed. Major factors affecting the disassemblability of configurable product are analyzed, and the disassembling degrees between components in configurable product are obtained by calculating disassembly entropies such as joint type, joint quantity, disassembly path, disassembly accessibility and material compatibility. The disassembly constraint relation weighted DSM of configurable product is constructed and configuration modules are formed by matrix decomposition and tearing operations. The disassembly constraint relation in configuration modules is strong coupling, and the disassembly constraint relation between modules is weak coupling, and the disassemblability configuration model is constructed based on configuration module. Finally, taking a hydraulic forging press as an example, the decomposed weak coupling components are used as configuration modules alone, components with a strong coupling are aggregated into configuration modules, and the disassembly sequence of components inside configuration modules is optimized by tearing operation. A disassemblability configuration model of the hydraulic forging press is constructed. By researching the disassemblability modeling technology of product configuration design based on disassembly constraint relation weighted DSM, the disassembly property in maintenance, recycling and reuse of configurable product are optimized.     

基于复杂网络的产品族结构建模及模块分析方法

将复杂网络理论应用于产品族结构建模中,提出产品族结构的零部件关系网络模型,零部件作为网络的节点,零部件之间的隶属关系作为网络的边,并在此基础上演化出产品族结构的模块关系网络模型.运用简单路径搜索等算法对各个节点的介数、次数和产品数等参数进行计算和统计.通过分析和比较这些参数,提出基于产品族结构网络模型的模块分类方法.在实例研究中,以某企业工业汽轮机产品族为例对上述方法进行验证.在分析网络模型相关参数的基础上,区分基本模块、必选模块和可选模块;寻找产品族中的关键模块并分析模块类型的转变是产品族演化的基础和关键.     

On the module identification for product family development

Modularity is the key to improve the cost-variety trade-off in product family development. This paper presents a methodology for identifying the constituent modules of product family. The methodology includes the following principles: (1) identify and isolate the individualized components into one module so that the product’s differentiation point is postponed; (2) identify and isolate the components with high possibility of being changed in the future into one module in order to improve the stability and commonality in the product family; (3) improve the functional independency of the modules so as to support the module configuration process and the functional extension of the product family; and (4) improve the structural independency of the modules so as to achieve higher efficiency in the module manufacturing process. These four principles are incorporated into a mathematical model and therefore the module identification problem is translated into a multi-objective combinatorial optimization problem. The problem is solved using genetic algorithm (GA). A case study is carried out on a gear reducer. Sensitivity analyses show that relative weights of each principle and different initial numbers of modules result in different module schemes.     

Natural frequency and mode shape analysis of structures with uncertainty

Two methods called random factor method (RFM) and interval factor method (IFM) for the natural frequency and mode shape analysis of truss structures with uncertain parameters are presented in this paper. Using the RFM, the structural physical parameters and geometry can be considered as random variables. The structural stiffness and mass matrices can then, respectively, be described by the product of two parts corresponding to the random factors and the deterministic matrix. The structural natural frequencies, mode shapes and random response can be expressed as the function of the random factors. By means of the random variable's algebra synthesis method, the computational expressions for the mean value and standard deviation of natural frequencies and mode shapes are derived from the Rayleigh quotient. Using the IFM, the structural parameters can be considered as interval variables and the computational expressions for the lower and upper bounds of the natural frequency and mode shape are derived by means of the interval operations. The effect of uncertainty of individual structural parameters on structural dynamic characteristics, and the comparison of structural natural frequency and mode shape using the RFM and IFM are demonstrated by truss structures.     

基于POV的旋转LED动态图像显示屏

针对传统LED点阵显示屏价格高、器件数目多及不易维护等问题,提出基于视觉暂留特性、以动态扫描方式完成旋转动态显示屏的设计方法。设计以STC12C5A32S2单片机为主控制模块,DS1302时钟芯片作为时间的设置与采集模块,DS18B20作为温度的采集模块,通过上位机进行图片和文字的转换和编辑,以单排高精度发光二极管的旋转实现了动态图像显示的功能。显示屏可实现动态文字、图像、实时时钟及实时温度的显示。     

Optimisation of opportunistic maintenance of a multi-component system considering the effect of failures on quality and production schedule: A case study

For a manufacturing equipment, any unplanned breakdown during the production period results into a high production loss. To keep the manufacturing facilities in good condition, preventive maintenance is planned. However, because of limited time and availability of resources, not all the system components can be or need to be repaired/replaced during a planned opportunity. Hence, the unplanned breakdowns can also be considered as an opportunity to do the maintenance activities for other components to take the advantage of economic dependency in multi-component system. However, when the system is under maintenance, it is very conservative to take the decision of maintenance actions on the components because of limited available time and resources. For such situation, this paper consider an opportunistic maintenance model for a multi-component system to take maintenance decision with a constraint on available time and the system availability requirements. The maintenance decisions for each component involves one of the three actions namely, repair, replace or do nothing to achieve the target availability with minimum maintenance cost. The model also considers the effect of component failures on the quality of product being manufactured as well as the production schedule on the machine. The cost of rejections is considered in the total failure cost along with the maintenance and downtime costs. The production schedule delay factor is considered as a constraint for the maintenance decision to account for the effect on production schedule delay. The optimal solution for the model is obtained using three solution methodologies namely simulated annealing, genetic algorithm and sequence heuristics. Using a real-life example of high pressure die casting machine, the opportunistic maintenance approach is demonstrated and results are discussed.     

基于公理设计和模块关联矩阵的产品族设计耦合分析

针对产品族设计耦合问题,分析比较了其与单一产品设计耦合的异同之处,提出了一种基于公理设计和模块关联矩阵的耦合分析方法。以公理设计为指导,进行功能需求分析及类型划分;分析了产品族客户需求、功能要求、设计参数和模块之间的对应关联关系,考虑适应性设计参数的影响度并将其分为两类以确定产品族的共性和差异性;从策略层面减弱产品族设计的耦合性。从操作层面的角度,根据设计参数零部件间的综合关联关系,通过聚类重构生成几个相互之间具有较小依赖度的模块,分析设计参数间的变更传播关系,建立产品族模块关联矩阵;从模块内部的耦合和模块之间的耦合两方面探讨了关联特性。最后通过电力液压盘式制动器实例阐述了产品族设计耦合分析过程。     

A value-based maintenance optimization method for failure prevention based on reliability modeling of a hybrid assembly system

The effective maintenance policy for the fixtures of the assembly system will guarantee good process capability and product quality to a great extent. Traditional maintenance schedules for the assembly system, such as a constant reliability index as the maintenance trigger, are always based on the fixed maintenance threshold in engineering practice. It always results in down time of the process, unqualified products or the excessive maintenance costs. The aim of this paper is to present a method to optimize the maintenance schedules for a serial-parallel hybrid assembly system. Based on the production chain definition of the hybrid system, a reliability evaluation method by integrating the process performance of the hybrid assembly system and product qualities is proposed. On the basis of the reliability method, a value-based preventive maintenance optimization policy for the fixture components is presented to prevent system failures. Compared with the traditional reliability threshold method for maintenance, the proposed maintenance method generates more value on the premise that the system status and product quality are guaranteed. A case study is used to illustrate the proposed method and validate the effectiveness and advantages.