基于支持向量机和Bayes方法的机械系统可靠性综合方法

针对机械系统可靠性评估问题,提出基于支持向量机和Bayes方法的可靠性综合方法.选用统计学习理论中的支持向量机算法,对机械系统可靠性进行了综合,得到由单元折合到系统的可靠性验前分布;然后,加上系统试验信息,利用Bayes方法得到系统的验后分布,进而得到系统可靠性评估值.最后通过圆柱齿轮减速器可靠性评估验证该方法的可行性.     

基于贝叶斯信息融合的制造执行系统可靠性增长分析

以企业制造执行系统(MES)工程为背景,以复杂系统可靠性增长模型与评估方法为研究内容,围绕制造执行系统的任务可靠性及其目标值和系统可靠性增长试验进行分析。针对MES功能复杂和试验数据不易获得等特点,根据试验信息以及工程咨询专家的经验,利用基于共轭型先验分布的贝叶斯信息融合方法,对MES各功能模块可靠度进行评估。利用模糊先验信息下的可靠性增长分析方法,对MES功能模块失效率的Bayes点估计值进行研究,解决了复杂系统在故障原因不易确定等条件下对复杂系统及其功能模块进行可靠性增长试验的问题。     

基于任务可靠度的电动伺服机构可靠性验证试验设计

针对某型火箭第三级发动机尾喷管姿态控制的电动伺服机构可靠性验证试验方法开展研究,采用Weibull分布模型确定了电动伺服系统的可靠性验证试验的试验时间,同时在对电动伺服系统任务阶段的环境应力和工作应力做了详细分析的基础上,设计了电动伺服机构可靠性验证试验载荷谱。针对电动伺服系统可靠性验证试验中小样本、无失效数据情况,提出了累计失效率的Bayes估计评估的方法。     

机动性雷达液压系统可靠性分析

现代战争对机动性雷达液压系统的无故障工作能力提出了很高的要求,为了评估液压系统工作可靠性水平,文中以某机动性雷达为例,详细阐述了液压系统的工作原理和组成,划分出7个功能模块子系统,建立了系统的可靠性框图和数学模型,并根据该模型,对系统进行了可靠度计算,给出了可靠度仿真曲线和分析结果,最后,提出了提高液压系统可靠性的几种有效方法,对机动性雷达液压系统的可靠性设计具有重要的借鉴意义.     

不完全Gamma分布下弹簧触指的可靠性寿命评估

针对高压断路器固封极柱内滑动联接用弹簧触指在极小样本无失效情况下的可靠性试验评估问题,采用不完全Gamma分布作为弹簧触指失效率的先验分布,基于多层Bayes可靠性评估方法建立概率模型,根据最小二乘法求出二参数Weibull分布中的待定参数,得到弹簧触指可靠性数学模型。研究结果验证了不完全Gamma分布作为失效率先验分布运用到多层Bayes方法可靠性评估中的合理性,为弹簧触指的可靠性评估提供了一定的理论指导。     

Bayes理论“小子样”数控机床可靠度评估法研究

针对“小子样”情况下的数控系统,以Bayes方法为理论基础,开展了适用“小子样”产品系统的可靠度综合评估方法的理论和应用研究。创新性地将系统可靠度Bayes方法运用在数控系统可靠性评估中。在系统可靠度Bayes近似评定方法的基础上,提出计算数控系统可靠度点估计值和置信下限。     

基于伪寿命分布和Bayes法的电主轴可靠性对比

分析混合陶瓷球轴承电主轴和钢球轴承电主轴的本质区别,设计了电主轴性能退化可靠性试验方案,并在该方案的指导下进行电主轴可靠性试验。针对单一采用伪寿命分布法或者Bayes法对电主轴可靠性评估精度不高的问题,提出了基于伪寿命分布法和Bayes法相结合的可靠性评估方法,应用该方法分别对两种电主轴试验样本的可靠性试验数据进行分析,最终获得其可靠性评估结果。同时,将两种电主轴的各个可靠性指标进行对比分析,获得其在可靠性方面的优劣。     

基于FMECA和神经网络专家系统的某型雷达可靠性分析

为了提高雷达系统可靠性分析的准确性,提出了一种故障模式、影响及危害性分析(简称FMECA)和神经网络专家系统相结合的可靠性分析方法,通过实例分析可以看出,二者结合运用于雷达系统可靠性分析,是非常方便有效的。     

针对小子样条件下的引信系统可靠性分析研究

在对引信进行系统可靠性评估时,因为缺乏系统级试验,单元器件可靠性试验数量较少,传统方法难以适用。针对小子样条件下的引信系统可靠性评估问题,在引信单元器件可靠性求解中引入贝叶斯方法,通过假设先验分布,可显著提高评估精度。在单元器件试验数据的基础上,通过数据折合和系统可靠性估计建模,可解决引信系统可靠度求解问题。     

人机协同制造系统可靠性试验与评估

人机协同制造系统可靠性对系统的运行具有重要影响,在建立人机协同制造系统可靠性模型基础上,提出人机协同制造系统可靠性试验与评估方法.利用某人机协同制造系统可靠性增长试验中积累的可靠性试验数据,估算出系统目前的可靠性指标,研究结果表明,该方法在系统可靠性分析中合理可行.     

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.     

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.     

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...