战斗机发动机温度过热故障挖掘模型仿真

为保证战斗机的飞行安全,战斗机发动机温度过热故障的快速检测至关重要。由于战斗机发动机在运转中随着转速和负荷的不同,发动机的油耗速度会存在波动或发生较大变化,油耗速度不可控,不同的存油量对发动机的温度影响不同,造成发动机温度变化随着油量的不同,信号特征存在非线性。传统的战斗机发动机温度过热故障挖掘模型,主要依据稳定温度信号特征检测过热故障,无法克服存油量波动造成的温度变化信号非线性失真问题,故障检测效果不佳。提出了一种融入诊断网络算法的战斗机发动机温度过热故障挖掘模型,采用小波变换方法,采集动态战斗机发动机温度过热故障信号特征,以温度过热信号特征为依据,通过融合诊断网络在隐含层中对温度过热信号挖掘过程中的数据进行传输,在输出层中对温度过热信号挖掘过程中的数据进行传输,得到过热温度变化信息,实现战斗机发动机温度过热信号的深度挖据。实验结果说明,采用所提模型能够提高战斗机发动机温度过热故障挖掘的准确性,有利于故障的快速修复。     

航空发动机气路传感网络的故障节点挖掘仿真

航空发动机的气路传感网络故障检测,是通过与发动机气路传感网络产生的基准线进行比较,产生的偏差作为阀值,作为检测故障的基础.由于航空发动机气路传感网络的高度非线性、噪声、测量不足等因素的影响,检测的基准线也呈现波动状态,传统的故障挖掘方法,需要通过做一些必要的假设,设置各种可能故障和性能恶化的范围,规定故障挖掘空间以降低波动干扰,但是上述假设降低了检测的精度.提出一种航空发动机气路传感网络的故障节点挖掘方法.计算故障传感节点的特征,为故障传感节点的挖掘提供数据基础.利用神经网络建立故障传感节点挖掘模型,完成故障传感节点的挖掘.实验结果表明,利用改进算法进行航空发动机气路传感网络的故障节点挖掘,能够有效提高检测的准确性和挖掘效率.     

非稳态故障信号的深度挖掘方法仿真分析

机械设备在运转中转速总会存在波动或者发生较大变化,与转速相关的故障特征频率也会产生一定的波动,甚至是较大范围的跳跃,设备振动故障特征频率存在非线性,很难用模型公式描述.传统的采用小波分解的故障特征挖掘方法,将信号分解到不同频段上,判断故障特征频率的一致性,上述方法诊断条件单一、规则惟一,一旦故障信号不完整或信号波动,就无法进行诊断.为了避免上述缺陷,提出了一种融合诊断网络算法的非稳态故障信号的深度挖掘方法.利用小波变换方法,提取非稳态故障信号的特征.再利用融合诊断网络,获取故障信息,从而实现非稳态故障信号的深度挖掘.实验结果表明,利用改进算法能够有效提高非稳态故障信号挖掘的准确性,有利于故障的快速修复.     

基于飞参数据的发动机碰摩故障检测模型仿真

在飞行实时状态监控过程中,强震动环境下的发动机碰摩故障检测的准确性,关系到飞行的安全.在强震动环境下,发动机转静容易发生碰摩故障,多个碰摩故障往往是同时发生的,但是,故障的振动信号之间不存在之间关联.碰摩故障特征彼此独立,故障特征数据之间缺少可直接建立的关联.传统的故障挖掘方法在发动机转静碰摩故障检测的过程中,只能 根据振动信号对这种故障进行检测,振动信号本身存在很多干扰,也很难包括所有的碰摩故障特征,导致故障检测不准确.为解决上述问题,提出采用改进关联规则挖掘的强震动环境下的发动机碰摩故障检测方法.针对飞机发动机碰摩数据进行关联聚类处理,获取样本空间的分类矩阵,并对发动机碰摩数据进行更新.根据更新结果,计算发动机碰摩数据关联概率值,得到概率决策,针对飞行器碰摩数据进行关联规则挖掘,实现发动机碰摩数据故障优化检测.实验结果表明,利用改进关联规则算法进行强震动环境下的发动机转静碰摩故障检测,极大的缩短了检测时间,降低了漏检率,提高了检测精确度.     

基于核直接分解的过热蒸汽系统故障诊断方法

为提高过热蒸汽系统的运行效率并减少非紧要故障的报警率,本文提出一种质量相关的非线性故障检测与诊断方法.首先,利用核函数将过程变量映射到高维特征空间以消除原始变量之间的非线性耦合.然后,在特征空间进行核直接分解得到两个正交子空间,并在两个子空间中分别设计统计量指标进行质量相关的故障检测.在此基础上,利用偏微分贡献图提取每个变量对联合统计量指标的贡献率,并根据贡献率大小最终确定故障变量.仿真结果表明,所提出的方法能够准确区分影响过热蒸汽温度和不影响过热蒸汽温度的故障,有效降低了非紧要故障的报警率,提高了过热蒸汽系统的运行效率.     

故障检测滤波器鲁棒性设计新方法

针对航空发动机动态过程中由于模型误差造成故障检测误报的问题,采用参数变化率法建立航空发动机动态线性变参数(LPV)数学模型反映发动机动态特性,同时结合全维非线性未知输入观测器,利用特征结构配置实现故障检测滤波器对于被控对象模型误差和系统不确定性因素的干扰解耦.通过某型涡扇发动机控制系统传感器故障检测仿真表明,减小残差信号与故障信号之间的误差,提高了残差信号对模型误差和未知输入信号的鲁棒性,对发动机过渡过程中故障检测准确度高,实时性好.     

基于LPV模型的鲁棒故障检测滤波器设计

针对航空发动机动态过程中由于模型误差造成故障检测误报的问题,采用雅克比方法建立航空发动机动态线性变参数(LPV)数学模型反映发动机动态特性,利用特征结构配置法设计故障检测滤波器,较好地消除了模型偏差对故障检测准确率的影响.通过某型涡扇发动机控制系统传感器典型软、硬故障检测仿真实验表明,该方法提高了残差信号对模型误差和未知输入信号的鲁棒性,对发动机加减速过渡过程中故障检测准确度高,实时性好.     

危险品运输车辆易燃信号挖掘方法研究与仿真

研究危险品运输车辆易燃信号准确挖掘的问题.危险品在车辆运输过程中,受到所处环境温度异常变化、外部颠簸摩擦等外部因素的影响,危险状况下的高温、高压等易燃信号随着外界干扰的不同会呈现非线性随机突变.传统的信号检测方法对异常信号非线性变化还没有很好的解决办法,无法正常捕捉,造成危险品运输中易燃信号检测不准.提出利用特征关联挖掘算法的危险品运输车辆易燃信号挖掘方法.利用小波变换方法,提取危险品运输车辆状态信号特征,去除干扰因素的影响,建立信号突变约束模型,计算危险品运输车辆状态信号特征之间的关联度,根据信号区域关联模型实现运输车辆易燃信号检测.实验结果表明,改进方法进行危险品运输车辆易燃信号检测,可以极大地提高检测的准确性.     

基于动态模拟技术的混动车辆发动机电控单元检测系统设计

电控单元是混动车辆发动机中的重要组成部分,对于发动机以及混动车辆的行驶性能产生直接影响,为保证电控单元的运行正常,利用动态模拟技术,优化设计了混动车辆发动机电控单元检测系统。改装温度、转速等传感器设备以及信号处理器设备,调整系统电路的连接方式,实现硬件系统的优化。利用动态模拟技术模拟混动车辆发动机电控过程,结合不同故障类型下电控单元的运行特征,设置系统的检测标准。采集电控单元输出信号,从时域和频域两个方面提取信号特征,最终通过特征匹配确定电控单元状态、故障类型以及故障位置,实现系统的电控单元检测功能。综合混动车辆发动机的三种运行场景,通过系统测试实验得出结论：与传统检测系统相比,优化设计系统的漏检率和误检率分别降低了2.59%和2.05%,由此证明优化设计系统具有良好的检测功能。     

光纤通信网络中故障优化诊断方法仿真

在光纤通信网络故障诊断问题的研究中,为及时准确的诊断出光纤故障,对光纤通信网络故障的检测需根据光纤通光后的信号异常曲线变化,完成各种故障判断.但是,由于在长距离的光纤通信中,通光后的故障信号随着传输距离的扩大,会发生较大程度的衰减,造成故障信号曲线发生非正常形变.传统的光纤故障检测方法只能根据采集的信号的异常变化判断光纤故障,对于光纤故障信号的长距离衰减形变无法与正常故障信号进行区分,容易出现误判.提出一种利用光功率值监测方法的光纤故障诊断方法.根据OTDR发射的激光脉冲信号在光纤中的后向瑞利散射和菲涅尔反射对光纤通信网络的功率值进行监测,并将样本的光功率值数据进行均值化处理,获取准确的OTDR故障曲线,为故障点的定位提供准确的数据基础.综合OTDR接收到的反射光功率值变化情况,最终获取准确的光纤故障点的定位.实验结果表明,利用光功率值监测方法对光纤故障进行诊断,极大的提高了诊断结果的准确性,缩短了诊断时间.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。