基于生产资源的柔性作业调度任务优选方法

市场需求的多样性与个性化趋势使面向订单的生产作业调度遇到极大困扰。一方面随机到达的订单往往远超出车间的生产能力,一方面车间资源经常使用不均,造成效率低下。对作业调度中的任务进行优化选择,是解决以上问题的有效途径之一。提出了满足订单要求及车间生产资源能力等多目标的调度任务优选方法,构建了柔性作业车间设备的可互换性规则和辨识算法,提出并研制了基于订单优先级、设备生产能力等约束下的订单多工艺方案自动平衡和优选算法,有效解决订单任务及生产资源共同约束下的柔性作业调度难的问题。通过对两个标准柔性调度案例的组合,以及相关目标和约束设计,对文章提出的方法进行了测试,结果表明,在保证订单交货期期限、遵守调度周期和设备维修约束等的前提下,采用此方法可使其makespan缩短13%,设备利用均衡,利用率达82.3%。     

多重不确定环境下考虑产品差异的再制造批量生产计划

针对多重不确定环境下制造／再制造混合生产场景中的批量计划问题，建立了库存和生产能力受限的混合整数规划模型。该模型分别采用已知概率的离散情景集合描述收回品数量和产品需求的不确定性，区间分析描述再制造成本的不确定性，以及随机机会约束描述再制造率的不确定性，并以需求满足率、运作成本和再制造产品率为运作目标，同时考虑再制造产品的差异，以单向替代策略增强生产计划的柔性。最后，将自适应机制引入双倍体遗传算法，设计了相应的求解过程，并对仿真算例进行了求解。计算结果表明，该计划模型和求解算法具有一定的有效性和实用性。     

产品族设计与供应商的订单分配关联优化研究

针对统一采购情形下产品族设计与供应商订单分配问题,提出了一个以产品族利润最大为目标,满足产品配置要求、供应商最小订单数量等约束的产品族设计与供应商订单分配关联优化模型,并开发了一种自适应遗传算法对模型进行求解。为了防止由于优化问题中存在的订单等式约束导致算法产生大量不可行的染色体,给出了一种按比例分配订单的染色体编码与解码方法。同时算法设计了自适应的交叉方式与变异方式尽可能避免陷入局部最优解。最后通过一个实例验证了所提优化方法和求解算法的有效性。     

面向云制造的多供应商协同生产任务分配优化

针对云制造环境下制造资源生产能力约束导致的任务分配不合理问题,研究建立了一种任务分配优化模型并提出了求解算法。依据子任务订单量对多个供应商进行生产组合,继而提出质量相似度等概念及其相应的计算方法,建立评价指标体系,并在此基础上构建了面向云制造的多供应商协同生产任务分配优化模型;通过对模型特征的分析与把握,提出一种改进的多目标粒子群进化算法,求解模型得到最优组合以及组合量。最后,通过实例证明了该模型与算法的可行性和有效性。     

云制造环境下跨企业协同生产调度算法

为解决云制造环境下的跨企业协同生产调度问题,提出一种适用于云制造环境下生产资源调度的混合集合规划方法。该方法基于切削算法框架,综合考虑多种约束,提出一种有效的求解策略,实现了一种面向订单且适用于跨企业、多约束、多品种、小批量的有限能力调度算法,为供应链中供需企业提供了一份拖期小、费用低、跨度短的协同生产计划。利用多组制造企业真实数据对模型进行测试,结果表明,该模型可在合理时间内有效求解实际应用规模的跨企业协同生产调度问题。     

基于约束满足的产品动态替补模型及算法

为解决订单在生产过程中因某动态因素导致其出现产品质量问题而无法按期交货的问题,建立了以最小化产品替补总成本和订单之间替补次数为目标的多等级产品动态替补模型;根据问题的特点,证明了该问题为NP完全问题;基于约束满足技术,提出求解该问题的动态产品替补算法。该算法旨在根据订单交货期紧急程度以及其中的产品等级进行产品替补以制定替补机制。通过实验验证了模型和算法的可行性和有效性,并且完全能在满足生产实际的条件下获得最优解。     

生产计划和车间排程问题的整数规划解法

为高级计划排程(Advanced Planning and Scheduling,APS)提出了一个混合整数规划(Mixed Integer Programming,MIP)模型,成功地对产品计划与车间排程问题进行了系统整合.模型综合考虑了多订单环境下生产能力约束问题,生产排序问题,提前时间,需求时间等因素,成功解决了生产计划和车间排程问题.     

基于改进人工蜂群算法的产品拆卸序列规划

为了提高复杂产品拆卸序列规划效率,提出了一种改进的人工蜂群算法用于此类问题求解。通过拆卸混合图表达产品零部件之间的连接关系和优先约束关系,并推导出可行拆卸序列的约束表达式,建立拆卸序列规划数学模型和适应度计算公式。对初始种群进行了优先约束规划,提出一种可行度算法用于蜂群对蜜源的搜寻与选择。定义了自适应选择参数、动态平衡可行度与适应度算法的优先配比,以实现复杂产品拆卸序列规划的快速求解。最后以内啮合齿轮泵为实例,利用所提方法进行了拆卸序列规划求解,通过分析实验结果,并对比传统人工蜂群算法,证明了该方法的可行性和高效性。     

考虑产品需求可替代的再制造批量生产计划优化

针对制造/再制造混合生产场景下的批量计划问题,建立了库存和生产能力受限的混合整数规划模型。该模型考虑制造/再制造商将回收产品加工为两种质量不同的再制造产品,高质量的再制造产品与新产品具有同质性,且当其生产数量超过需求量时,可以作为低质量再制造产品的替代品进行销售。设计了一种改进的合作协同进化遗传算法,引入种群多样性评价,对代表个体的选择数量进行动态调整,从而平衡算法的计算复杂性和优化解性能。实例仿真计算表明,该算法具有更高的求解质量和求解效率。     

带能力约束的多目标OEM协作生产订单分配决策与混合蚁群算法应用研究

在面向订单生产(build-to-order,BTO)的协作生产环境下,品牌制造商如何将所接受的不同客户订单(生产任务)分配给众多的协作生产企业OEM供应商,同时以最大的成本收益及最高的服务水平完成这些制造任务,是OEM协作生产环境下一个很实际的生产管理问题。首先根据此类问题的特点建立了一个带能力约束的、以总订单利润与准时交货为目标的多目标OEM订单分配模型;然后利用混合智能优化算法——模拟退火蚁群算法进行求解,并对该混合算法进行改进;最后应用算例验证了算法的有效性与合理性。     

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...     

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.     

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.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

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....     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.