基于GT编码的零件聚类树的建立

基于成组技术，提出了用零件分类编码的哈明距离函数来表达零件相似性。在此基础上，利用领域知识和概念性聚类的方法，将零件的属性分为有序属性和无序属性来表示其语义距离，并结合模糊表示方法对属性值进行规格化处理，从而根据零件之间距离的远近建立零件聚类树，为零件之间相似性建立层次结构，奠定了自适应的动态分类和工艺制作的算法基础。     

无人仓系统订单分批问题及K-max聚类算法

为了提高订单拣选效率、降低拣选成本,研究了以自动引导小车(AGV)为搬运工具的无人仓库系统订单分批问题.分析了影响订单拣选成本和效率的两种主要因素,建立了以订单分批拣选总成本极小化为目标的整数规划模型.根据K-means聚类算法思想,结合订单分批问题的优化目标,基于每批订单中包含的商品种类和拣选每批订单需要搬运的货架信息,利用取大(max)运算符分别定义了能够反映订单拣选成本的两种类中心,以及订单到两种类中心的距离.进一步以工作人员拣选每种商品的单位成本和AGV搬运一个货架的成本为权重,构造了订单到批次(类中心)的加权距离.在此基础上设计了K-max聚类算法求解订单分批问题.采用具体算例验证了K-max聚类算法的有效性.     

基于聚类分析法的典型工艺路线发现方法

为解决计算机辅助工艺设计系统从工艺数据中提取工艺知识的问题，提出了应用聚类分析法获取典型工艺路线的方法，建立了以矩阵表达工艺路线数据的数学模型。在工序编码的基础上，应用曼哈坦距离计算工序间的相似度。应用欧氏距离计算工艺路线间的相似度，并以相异度矩阵表示工艺路线的相异度。通过平均距离法计算工艺路线簇间的距离，并应用凝聚的层次聚类法进行工艺路线聚类。最后，通过工艺路线聚类粒度的确定方法确定聚类结果，并以轴套类零件典型工艺路线发现为例，验证了该方法的有效性。     

面向智能仓储的Kiva机器人拣货策略优化算法

针对电商仓储中Kiva机器人拣选存在效率低下和订单分配不合理等问题,构建了以Kiva机器人拣货总行驶距离最小为目标的订单分配优化模型,设计基于差异聚类和邻域搜索的优化算法来求解模型。以电商实际订单数据为例,分析了不同规模算例下该算法的性能和稳定性。结果表明：针对不同规模算例,基于差异聚类和邻域搜索的优化算法相比与Gurobi和基于差异聚类的算法能够在更短的时间内获得更优的结果,并且算法的稳定性较好。通过本项研究,决策者们可以将订单合理分配至各拣货单,从而提高仓库拣货效率。     

一种两类“货到人”订单拣选系统的适用性选择方法

提出一种能在两类"货到人"订单拣选系统(即自动存储及取货系统(Automated storage and retrieval system,AS/RS)和Carousel系统)之间依据不同订单类型进行系统适用性选择的系统优化方法。订单拣选系统最常用的两种作业策略分区策略和分批策略本质上都是对订单的聚类,因此订单可以被分为很多一维单元化网格;根据各系统的逻辑运动关系,得到单元化网格的拣选时间表达式;利用作业时间模型和空间填充线,对单元化网格进行聚类,得到二维系统的总订单拣选时间,采用遗传算法计算各系统的最优值;比较各系统的时间选择适用性,即选择总订单拣选时间更小的系统。通过对四类不同类型的订单进行试验研究,初步得出两类系统对四类订单的适用性分析和系统参数敏感性分析。     

制造企业基于风险水平的订单收益管理

为实现制造企业高效的订单管理,提出了不确定需求下考虑风险水平的订单收益分配方法,建立了考虑风险水平的订单收益分配模型。进一步运用Shapley值法计算了模型的收益分配系数,并引入风险修正因子对此系数进行了修正。最后采用数值分析的方法,对收益分配模型进行了验证,并对此模型进行了灵敏度分析。结果表明,该收益分配模型能够满足个体理性决策条件,能够较好的解决考虑风险的订单收益分配问题。该方法还可推广到多级供应链订单管理中,为制造企业订单收益管理提供了一种参考依据。     

一种面向订单剩余完工时间预测的SOM-FWFCM特征选择算法#br#

准确的订单剩余完工时间预测有助于动态调整生产计划、优化制造过程,以满足订单产品按时交付的需求。订单剩余完工时间受到车间物料、设备、在制品等各类生产要素的综合影响,相关数据具有典型的大量、多维、高冗余的特点,有效的特征选择能够获得更高的预测精度。在构建候选特征集的基础上,提出了一种基于自组织映射（SOM）网络特征加权模糊C均值（FWFCM）的特征选择算法。通过构建SOM网络初始化FWFCM的聚类中心,减少后者对初始聚类中心的依赖;基于互信息计算特征权重,实现导向性特征聚类,根据聚类结果选择特征代表,构成高质量关键特征子集。以某机加工车间的生产数据为例,通过与其他4种特征选择算法的对比分析,验证了所提算法的有效性。     

基于聚类算法的订单分批策略研究

订单分批是物流中心提高作业分拣效率的一个有效方法。主要针对“货到人”模式下的订单分批问题,构造了基于聚类算法的数学模型,并以最小化货物搬运次数为目标函数进行求解。通过在不同规模的订单数据下,比较基于聚类算法的分批策略与采用先到先分批策略、不分批策略在拣选作业中的实际效果,表明该算法能有效提高分拣任务的作业效率。     

基于相似实例的板构件产品配置方法

为满足大批量定制生产板、框类产品的需要,分析了该类产品的相似特征,提出了板构件产品的配置模型。通过加权欧氏距离的聚类算法来计算历史实例和待求目标产品间的相似度,进而解决配置过程中相似实例的提取问题,采用配置知识库来优化配置结果,实现了基于相似实例的板构件产品配置方法。以起重机主梁产品的配置设计为例,说明了该方法的实用性。     

基于聚类分析的白车身零件工艺模板提取

为提高白车身工艺规划的效率,提出了基于聚类分析的白车身工艺模板提取方法。按照白车身装配的典型工艺,将其分为装配定位工序、连接工序和检验工序三类。采用专家打分法计算装配定位工序间的距离。对连接工序进行四位数字编码,在此基础上应用曼哈坦距离计算工序间的距离。为了提高距离计算的正确性和科学性,采用二值属性间距离公式求解检验工序间的距离。采用层次聚类法对白车身工艺聚类,用均方差法从聚类结果中提取了每个簇的工艺模板。通过实例验证了该方法能有效提取白车身零件的工艺模板。     

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.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

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。     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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.