飞控系统传感器故障诊断的在线方法研究

传感器是飞行控制系统当中的一个重要组成部分,在系统中往往利用传感器的各个输出来建立飞机的动态状态;因此,实时准确的对传感器进行故障检测和识别可有效地提高系统的安全可靠性;提出一种带有可变遗忘因子的BP神经网络在线递推学习算法,应用改进的算法对飞行控制系统的传感器故障进行实时在线的检测和识别,且利用神经网络的输出对系统进行重构;仿真结果表明提出的方法可准确的对传感器的故障进行故障诊断和容错控制.     

基于检测滤波器的俯仰角速率传感器故障检测研究

针对飞控系统俯仰角速率传感器故障情况复杂以及故障检测困难的问题,通过分析飞控系统俯仰角速率传感器的故障种类和故障模式,建立不同情况相关数学模型;依据检测滤波器法检测系统故障的原理,设计飞控系统俯仰角速率传感器故障检测的滤波器;在某飞机处于Ma=0.8,H=50m的飞行状态,利用Matlab和Simulink对飞控系统俯仰角速率传感器故障检测进行仿真验证,仿真表明所建证的飞控系统传感器故障数学模型是正确的,同时表明滤波器检测故障的方法可以高效地检测出飞控系统俯仰角速率传感器的故障.     

基于MATLAB的自修复飞控系统仿真

可靠性和可维护性是当代飞控系统面临的首要问题,自修复飞控系统在解决这两方面问题的同时,提高了飞机的生存能力。采用ＭＡＴＬＡＢ仿真语言,开发出自修复飞控系统仿真平台,实现了收音机的全面运动仿真。同时,根据自修复飞控系统的需要,可进行了收音机故障的加载,以及对故障进行检测、隔离和估计,然后完成飞行重构,具备了完整的自修复飞控系统信息功能。     

基于直接自适应控制的重构飞控系统研究

通常，飞控系统重构设计需知系统的故障信息，而使用直接自适应控制技术可在不知道系统故障信息的情况下，对飞控系统操纵面损伤进行重构，并且可使故障飞机很好地跟踪参考模型的输出．采用优化算法设计反馈补偿器以保证故障系统的严格正实性，并利用Lyapunov函数证明重构系统的渐近稳定性．将该方法用于某型飞机侧向控制系统的设计，仿真结果表明，在操纵面严重受损的情况下，飞机仍能保持良好的性能．     

基于残差决策的自动飞行控制系统远程实时故障诊断

针对自动飞行控制系统结构复杂、关联部件众多,发生故障时诊断时间长,从而影响飞机运行效率的问题,提出一种基于飞机通信寻址报告系统(ACARS)的远程实时故障诊断方案。首先,分析自动飞行控制系统的故障特点,设计搭建检测滤波器;然后,利用ACARS数据链实时发送的自动飞行控制系统的关键信息进行相关部件的残差计算,并根据残差决策算法进行故障诊断及定位;最后,针对不同故障部件残差间的差异大、决策门限无法统一的缺点,提出基于二次差值的残差决策改进算法,减缓了检测对象的整体变化趋势,降低了随机噪声和干扰的影响,避免了将瞬态故障诊断为系统故障的情况。实验仿真结果表明,基于二次差值的改进残差决策算法避免了多决策门限的复杂性,在采样时间为0.1 s的情况下,故障检测所需时间大约为2 s,故障检测时间大幅降低,有效故障检测率大于90%。     

基于DSP的飞机防滑刹车系统检测装置

介绍了基于DSP(TMS320LF2407A)和USB(ISP1581)的飞机防滑刹车系统检测装置。该检测装置能够检测防滑刹车控制盒和防滑刹车系统相关附件的故障信息,并通过USB总线把检测结果送给上位机,为飞机刹车事故分析、处理和预防提供依据。实际运行表明,该装置能够快速准确地检测出飞机防滑刹车系统的故障,并实现检测数据掉电不丢失。     

AFCS自动测试系统的设计与实现

介绍了一种自动飞控系统(AFCS)测试系统的设计和实现,对其中主要硬件的设计和上层测试软件的设计思想做了讨论.采用该自动测试系统后,AFCS系统检测时间从约4 h降为20 min,测试效率大为提高.     

基于LabVIEW的汽车保险盒回路质量检测系统

汽车保险盒作为汽车电路中的重要保护元件,其出厂质量应该得到严格保证;为快速准确地检测该产品质量,文章采用美国NI公司的图形化开发环境LabVIEW基于双状态机结构成功地开发出一套高效、准确、稳定的检测系统,该系统可实现数据采集、检测信息即时显示、故障原因分析与显示、数据保存等功能;实际使用证明该检测系统运行稳定可靠,系统可在15s之内完成对某型号汽车保险盒的17片熔断器安装位置以及由55个外接引脚形成的99路"连通-断开"回路检测,大幅提高检测效率与检测质量.     

基于扰动估计的飞行控制系统传感器故障重构

针对飞行控制系统的传感器故障重构问题,讨论了基于扰动估计的传感器故障检测与重构方法。首先,通过建立观测器,对已有系统的干扰进行估计;其次,通过干扰的估计值来建立系统的鲁棒观测器;最后,再通过对系统建立多个降维鲁棒观测器来隔离并重构传感器故障。采用某飞机横侧向模型进行仿真验证,仿真表明基于扰动估计的鲁棒观测器能够有效地对传感器故障进行隔离与重构。     

飞机刹车系统故障诊断方法及其应用研究

刹车系统是飞机着陆制动的重要系统,其故障将直接影响飞机着陆安全.现阶段刹车系统多采用故障树分析法进行事后诊断,对故障预防效果有限.运用一元线性回归分析方法建立刹车系统输出刹车压力的预测区间,修正后作为刹车压力应正常分布的区间,将该区间作为检测手段并结合故障征兆判据,对刹车系统现有工作数据在区间上的分布情况进行分析和判断...     

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。