基于多假设解分离算法的BDS/SINS紧组合完好性监视

完好性是民航基于性能的导航（PBN）运行的关键性能要求,是导航安全性的重要支撑。北斗导航系统（BDS）/惯性导航系统（SINS）紧组合导航系统将SINS信息加入到完好性监视中,增加了冗余信息,通过多假设解分离算法进行故障卫星的检测与隔离,满足民航特定飞行阶段高完好性要求。论文利用BDS接收机接收到的BDS卫星数据,通过设置飞行轨迹,模拟卫星故障,对BDS/SINS组合导航系统的完好性算法进行测试验证。实验结果表明,基于多假设解分离方法的BDS/SINS紧组合导航系统可以较好地实现故障卫星的检测与隔离,保护限计算符合预期。     

SINS/GPS/BDS紧耦合系统研究

随着北斗卫星组网的推进,SINS/GPS/BDS组合导航系统应用前景广阔。针对SINS/GPS/BDS紧耦合系统,首先研究了紧耦合系统的卡尔曼滤波算法,在此基础上与松耦合系统、纯惯导进行比较,对SINS/GPS/BDS紧耦合系统性能进行仿真研究,最后利用残差检验法对紧耦合系统的故障检测性能进行了仿真;结果表明,紧耦合系统具有优越的性能,采用紧耦合系统能扩大组合导航系统的应用范围,便于故障检测。     

卫星信号失效条件下SINS/GPS不同组合方式的性能比较

为了研究卫星信号失效对SINS/GPS松组合导航系统和紧组合导航系统导航性能的影响,在分析惯导系统误差方程的基础上,给出了基于卡尔曼滤波的松组合和紧组合数学模型,构建了两种组合方式的仿真平台。仿真结果显示,SINS/GPS紧组合导航系统的精度要明显优于松组合导航系统,且在卫星信号失效导致可见星数目少于4颗甚至仅有1颗时,SINS/GPS紧组合依然能够保持组合模式,并可提供高于单一惯性导航系统的导航精度,说明了SINS/GPS紧组合方式具有较高的精度和可靠性。     

机载北斗/GPS/SINS组合导航系统软硬件设计

针对单一导航导航系统在导航精度、稳定性、设备成本以及导航信息完备性等方面的局限性,设计了卫星导航/惯性导航组合导航系统;针对GPS导航系统受制于人及北斗导航系统发展尚不完善的特点,提出了基于北斗/GPS/SINS的军用机载组合导航系统软硬件设计;搭建了北斗/GPS/SINS组合导航系统硬件平台,采用基于不确定度的加权平均数据融合算法提高组合导航系统的导航可靠性和准确性;仿真结果表明,该组合导航系统稳定性好,可靠性高,定位准确。     

基于联邦滤波的偏振光/SINS/BDS/地磁组合导航算法

针对高稳定目标导航参数获取对多传感器融合算法的需求,提出一种偏振光/捷联惯性导航系统(SINS)/北斗卫星导航系统(BDS)/地磁组合导航方法.分析了各类传感器的导航性能,采用联邦卡尔曼滤波器两级结构,利用子滤波器进行局部估计,主滤波器进行多传感器数据融合,研究了基于联邦卡尔曼滤波方法的多传感器数据融合导航算法.进行了...     

惯性基高精度组合导航方法研究与仿真

研究了一种基于捷联惯性导航系统(SINS)的高精度组合导航方法;选取SINS的系统误差作为组合导航系统状态,利用天文导航系统(CNS)输出的姿态矩阵和SINS输出信息计算得到的等效姿态矩阵来构造量测,设计SINS/CNS组合导航算法;利用SINS与北斗卫星导航系统(RDSS)各自的位置输出构造量测,设计SINS/RDSS组合导航算法,从而,利用联邦卡尔曼滤波技术设计SINS/CNS/RDSS组合导航算法;仿真结果表明,惯性基SINS/CNS/RDSS组合导航方法具有较高的导航定位精度,工程应用前景良好。     

基于微处理器的紧耦合组合导航系统设计

首先分析了GPS导航与惯性导航各自的优缺点,阐述了GPS/惯导组合导航系统的先进性,其次介绍了众多组合模式中的利用伪距和伪距率信息的紧耦合组合模式,最后基于微处理器从软硬件两方面对组合导航系统进行了设计.     

车载低成本GNSS/SINS紧组合导航系统设计

针对GNSS/INS松组合导航系统在可见星数少于4颗的情况下无法正常工作的问题,设计了基于ARM的车载低成本GNSS/SINS紧组合导航系统。以AM3354为电路核心处理器,集成了惯性IMU MPU-9150和卫星接收模块NV08C-CSM。通过I2C和 UART接口完成数据采集,送入导航解算后经由SD卡和UART实现数据的保存与上传。系统算法采用离散扩展卡尔曼滤波进行紧组合的数据融合,在没有足够的卫星来计算独立GNSS参数时,也能够将卫星信号输入组合系统并辅助SINS。为验证系统可行性进行了实测跑车实验。结果表明,所设计的紧组合导航系统精度满足车载应用,较松组合算法表现出了更高的精度和稳定性。     

DSS/SINS组合导航实时滤波仿真

北斗双星定位系统的定位原理决定了其存在导航定位实时性较差的缺点。为了解决双星定位实时性差的问题,提出了一种新的北斗双星／SINS组合导航实时滤波方法,即对双星定位的静态误差进行建模,将静态误差模型作为其动态误差的残差模型与双星定位时间延迟随机常数一起扩充为组合导航滤波器的状态变量,然后对北斗双星／SINS组合导航系统进行状态估计的滤波方法。通过计算机仿真,结果表明该实时滤波方法能够更好地解决北斗双星／SINS组合导航在实际工程应用中定位实时性较差的缺点,从而提高了组合系统的导航精度,对北斗双星／SINS组合导航系统的实际应用有重要的参考价值。     

捷联惯导/北斗高精度组合导航方法研究

提出采用紧组合方式进行捷联惯导/北斗组合导航设计,首先对捷联惯导与北斗系统进行误差分析与建模,将捷联惯导系统误差、北斗等效时钟误差相应的距离(伪距误差)以及等效时钟频率误差相应的距离率(伪距率误差)作为组合导航系统状态;利用捷联惯导位置输出与北斗接收机星历输出构造获得等效伪距,将其与北斗接收机测量的伪距对应相减作为量测,推导建立对应的量测方程,采用卡尔曼滤波设计捷联惯导/北斗组合导航滤波算法;仿真结果表明,该组合导航方法的速度精度达到±0.05 m/s,位置精度达到±3.2 m,水平姿态精度达到±0.4′,航向精度达到±1.6′。     

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     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。