基于仿真评价的产品开发过程改进技术研究

针对过程研究中过程模型描述不完整、缺乏有效的改进评价支持等问题,研究了一种基于仿真评价的产品开发过程改进技术.在该技术中,建立了结合矩阵结构与图形化结构的双层过程模型作为改进研究的支持模型,研究了基于模型的过程迭代改进方法.在过程仿真研究基础上,采用相对评价模式建立过程改进的仿真评价模型.结合改进与评价技术,提出了支持过程持续改进的改进模式与策略,通过多次循环改进与评价,剔除无效的过程重组环节,实现了过程改进的可控性.根据理论框架开发出过程改进原型系统,并以液压减振器开发过程为例进行实现,结果表明,该方法有效改进了开发过程,提高了产品开发效率.     

大孔管子车床纵向进给换向机构的改进

简要介绍了大孔管子车床纵向进给换向机构的改进。分析了原设计机构的缺陷,简要讲述了改进过程和改进的工作原理。实践证明,该换向机构改进达到了预期的目标,提高了机床运行的可靠性。     

台式桌面喷墨印刷导电油墨试验台的改进设计

为提高台式桌面喷墨印刷导电油墨试验台的印刷套印精度,在改进前的试验台上进行套印试验,分析影响试验台套印精度的主要因素,据此进行试验台改进设计,提高试验台套印精度.提出了一种高精度的喷墨印刷导电油墨试验台方案,完成了试验台的改进设计.在改进后的试验台上验证改进效果,得到改进后试验台的印刷套印精度达到30μm,比改进前的试验台提高67％,达到了印刷电子套印精度要求.     

基于遗传算法的摆动活齿传动多目标优化设计

本文建立了摆动活齿传动的优化设计数学模型,提出了优化设计方法。为求得全局最优解,引进了遗传算法。文中对遗传算法提出了一些改进,并用改进前、后的遗传算法分别对该模型进行了优化仿真计算,结果表明改进后的遗传算法优于改进前的遗传算法。     

汽油机排气歧管结构的优化及验证

分析某四缸汽油机排气歧管结构设计存在的缺陷并对其进行改进优化,采用数值模拟仿真软件分别对排气歧管改进前和改进后通道的各缸排气背压及歧管排气气流均匀性进行仿真,仿真结果表明改进后排气歧管结构能明显降低排气背压和各通道不均匀性。最后对原歧管和改进后歧管搭载的汽油机进行了台架对比试验,试验结果表明搭载改进后排气歧管的汽油机不仅提高了原机的外特性扭矩而且降低了燃油消耗,进一步验证了排气歧管结构改进优化的可行性。     

高海拔柴油发动机性能改进研究现状与发展趋势

本文总结了我国高原地区环境特点、海拔高度等环境因素对柴油发动机性能的影响,综述了国内外高原条件下柴油发动机起动性能改进、燃烧性能改进和排放特性改进三个方向的研究现状,分析了柴油发动机性能改进的发展方向。最后,针对柴油发动机高海拔工况下的性能需求,提出柴油发动机多参数协同优化研究是柴油发动机性能改进的重要发展方向。     

重载油缸坯料搬运系统模态分析与结构改进

基于有限元法,对重载油缸坯料搬运系统进行模态分析,得到了前六阶振型和固有振动频率。对其模态特性进行了分析,找到结构刚度的薄弱点,进而对系统整体结构进行了改进设计。通过改进设计改善了结构模态特性,提高了系统的稳定性和安全性。通过锤击法对改进后的整体模态特性进行了实验验证,并由实验结果的模态参数辨识验证了改进设计的有效性。这种分析改进方法可以推广到其它机械设备的结构改进中,具有较大的工程实用价值。     

22Y-F1型伞式流量仪的改进

本文简单介绍了22Y-F1型环空测井伞式流量仪的结构及缺点,并针对其缺点提出了两项改进:对流量传感器涡轮部件结构的改进和对布伞的改进,此设计的改进将为以后小直径仪器的设计和改进提供参考和借鉴。     

散装水泥车改进前后动态分析对比

利用有限元分析软件ANSYS对改进前后的散装水泥半挂车罐体和车架整体进行了动态分析,包括模态分析和谐响应分析,并且对改进后模型结构的继续优化改进提出建议,为其结构的改进设计提供了可靠的理论依据。     

结合图像增强的含噪齿轮图像边缘检测研究

为了提高齿轮后期故障检测和缺陷检测的效果,并有效去除图像中的混合噪声,提出了一种结合图像增强的含噪齿轮图像边缘检测算法.首先,引入了信息熵改进了马氏距离公式,并将马氏距离用于改进自适应中值滤波器;然后,对幂次变换进行了改进,使其具有自适应性,并将改进的幂次变换用于改进Retinex算法,对图像整体进行了增强;最后,采用...     

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.     

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。     

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....     

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.