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、经济性和环境属性等要求,基于全链接层次聚类法进行了模块聚类,得到了机械产品可再制造升级模块划分方案;最后,以永磁同步曳引机为研究对象,对所提方法的可行性进行了验证。研究结果表明:该方法能有效地对机械产品进行可再制造升级模块划分,模块内部零件之间的联系紧密,且具有很高的装配性,模块之间又有很高的独立性,易于机械产品的再制造升级。     

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.     

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。     

产品模块划分方法研究综述

模块化设计通过合理的产品模块化体系,快速地组合成满足客户需求的个性化产品,同时又因为通用模块的批量生产和管理降低成本。从而有效解决产品在低成本、高质量和满足顾客的个性化需求之间的矛盾。作为产品模块化设计的关键技术,模块划分一直是工程领域研究的热点问题。将目前已有的模块划分方法归纳为基于功能的模块划分方法、基于功能和结构的模块划分方法和面向产品生命周期的模块划分方法等几种类型,并对模块划分方法进行了分析和总结。     

包含构件成组约束的多目标产品架构模块划分

针对传统的基于设计结构矩阵和设计产品矩阵/模块指示矩阵的产品模块划分方法中优化解往往不符合特定构件局部成组的实际要求、粒度过大等问题,提出一种包含局部成组约束条件的多目标优化方法。设计人员根据设计结构矩阵和设计产品矩阵/模块指示矩阵的单独聚类结果以及先验知识确定所期望的特定构件局部成组方案。建立以设计结构矩阵的模块度、设计产品矩阵/模块指示矩阵的正交度和模块内聚度为优化目标、以局部成组方案为约束条件的聚类优化模型。采用改进型非支配排序遗传算法对该问题进行求解,得到Pareto解集;利用逼近理想解排序法帮助设计人员在Pareto解集中选择出合适的折衷解作为模块划分方案。以手提式吸尘器的模块划分为例,运用数值仿真手段验证了该方法的有效性和可行性。     

基于质量功能屋的产品服务系统模块划分一致性检验评价方法

在产品服务系统(Product-Service System,PSS)的交互式模块化设计中,用户需求、物理模块之间、服务模块之间,以及物理与服务模块之间可能存着诸多冲突。寻找合适方法发现并解决模块间的冲突,保证物理模块与服务模块的粒度一致性是实现PSS配置设计的关键点之一。首先,分析模块划分后一致性评价原则,明确一致性评价内容;然后,建立一个五步骤的模块一致性评价过程模型,通过采用基于质量屋和T检验方法来检验模块划分的一致性;最后,采用广义变压器的模块划分评价案例进行应用验证。此方法有效保证了物理模块与服务模块在PSS主结构中的一致性,在产品与服务配置中不会发生冲突。     

基于可适应设计和工程更改同步演化的产品设计方法

可适应设计和工程更改在应对客户需求变化方面具有一致性,但二者对产品功能变异与结构变型的处理方式不同。为实现产品设计的适应性,分析了可适应设计和工程更改互为补充的原由,以及融合的必要性,探讨了产品适应性更改演化过程。采用质量功能配置方法分析适应性更改需求,基于公理设计和通用设计理论构建了功能-结构-属性映射模型,采用功能要求矩阵、设计参数矩阵及结构属性元模型描述适应性更改演化步骤,实现可适应设计和设计更改的融合。以卷扬机为例阐述了适应性更改过程,为企业更好地管理设计资源与知识并提高产品设计的效率和个性化水平提供方法支持。     

面向农机模块化产品平台的零部件关联度建模与计算

为了实现农机模块化产品平台中产品零部件相关资料管理,最终实现农机的快速设计,需要对产品零部件进行模块化。产品模块化首先需要构建以农机零部件关系大小为目标的模型,再通过合理的关联度的计算方法计算农机零部件之间的关联度,形成农机零部件关联度的DSM(设计结构矩阵)矩阵,进而通过算法优化矩阵并得到优化结果,最后根据结果判定模块的划分,从而验证模型以及关联度计算方法的合理性。通过遗传算法对DSM矩阵进行优化,最后把这些零件划分为5个模块,其中4个功能模块,分别取名扶手架模块、扶手支臂模块、扶手座模块、附件拉杆模块,和1个独立零部件模块。通过对比农机实物与划分结果可知,关联度计算方法具有合理性。     

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。     

基于模块化设计的泥浆泵组设计方法研究

该文根据模块化设计流程,首先进行泵组产品的属性分析,根据属性分析,列出产品属性关联列表,然后建立产品属性矩阵,进而进行泵组的模块划分,并列出各个模块之间的接口,讲述了接口的定义方法。以泵组为例,详细叙述了模块化设计流程、模块实体的存储方法、模块化产品配置系统等,最后通过对F1600泵组的模块化设计研究得出了五点结论,为后续模块化产品的设计提供了参考。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....