惯性/光流/磁组合导航技术在四旋翼飞行器中的应用

微小型无人飞行器(MUAV)通常采用微惯性/GPS组合导航系统提供载体速度、位置、姿态等参数.然而GPS信号易受干扰,且面对特殊环境(如高楼林立的街道、隧道、峡谷等)易出现信号丢失情况,难以满足飞行器的自主安全飞行要求.为解决该问题,设计基于光流法辅助微惯性导航的无GPS自主导航方案,提出了一种基于无味卡尔曼滤波(UKF)的非线性融合导航方法,基于四旋翼飞行器的悬停和飞行实验进行了验证.实验结果表明:该方案具有成本低、导航自主性强、精度高的优点,具有一定的应用参考价值.     

无人潜航器DVL测速组合定位校正阻尼抑制方法

为了抑制无人潜航器工作过程中舒勒振荡对导航精度的影响,本文提出了一种无人潜航器DVL测速组合定位校正阻尼抑制方法。无人潜航器由于其特殊的工作需求,经常需要在水下停留或航行较长时间。由于其隐蔽性能的需要,不能够经常浮出水面通过GPS进行位置校准。舒勒振荡在无人潜航器短时间航行时并不会产生较大影响,而当无人潜航器长时间航向时,就会对系统产生不可忽略的误差。为了解决这个问题,本文提出了外速度阻尼网络。并且为了得到更精确的外速度信息,引入外速度加权融合算法。通过与无阻尼系统对比的仿真实验验证了外速度阻尼网络在无人潜航器导航中可以有效抑制长时航行时舒勒振荡对系统的影响。     

基于高速GPS的道路测速设备计量校准系统

为了解决道路测速设备计量校准困难的问题,本文给出了一种基于高速GPS的道路测速设备计量校准系统的实现方法。速度采集设备采用精度达到0.1m/s、数据输出速度可达到10次/秒的高速GPS测速模块,主控设备采用一台笔记本电脑加配套专门开发的控制软件,显示设备采用高亮度LED显示屏。通过主控系统软件可把GPS获得的速度数据实时的显示在LED显示屏上面。把本套系统安装到测试车辆上,可对道路车辆测速设备进行精确的计量和校准。本系统具有操作简单、计量精度高等优点。     

无人直升机嵌入式控制系统的实现

基于AT91RM9200(ARM)微型控制器,结合适当的外围设备,构建了一个高集成度的嵌入式系统,实现微型无人直升机的飞行控制.在μC/OS-Ⅱ操作系统环境下,详细介绍了软件系统的总体结构和任务之间的切换过程.最后,针对直升机的姿态和位置控制,分别给出了适当的控制策略.     

基于GPS/DR的GPS滞后时间自适应检测算法

针对GPS输出信息的随机延迟特性,基于航位推算(DR)系统惯性器件的实时性与短时高精度,提出了航向差和速度自适应GPS滞后时间检测方法,在此基础上,对GPS和DR数据进行数据对准,提出了自适应GPS滞后时间处理算法。在GPS/DR实际系统中的应用结果表明,本算法能够准确检测出GPS的滞后时间,提高车辆的定位精度。     

GPS在降落伞导航控制与速度测试中的应用

结合项目实际,介绍了利用GPS开发降落伞导航控制和速度测试系统的设计方法及关键技术,解决了利用低成本单片机实现GPS数据实时处理和输出的困难,并提出了一种高精度、简便的降落伞飞行速度测试方法。利用其GPS的测速功能,测定降落伞的飞行速度,解决了传统的激光测速精度低、采样率低、操作不便和成本高的缺点。     

基于伪距的GPS/INS滤波算法设计及仿真

提出一种以伪距和伪距率作为观测量的GPS/INS组合导航算法,使其适用于嵌入式GPS/INS组合导航系统产品的开发.针对目前市面卜的AHRS(姿态航向参考系统)的输出数据特性,以及课题组开发的GPS接收机的输出数据特性,提出一种简单易行的卡尔曼滤波算法.将姿态四元数递推方程与ECEF系下的位置、速度递推方程分别进行卡尔曼滤波,然后将滤波后得到的结果按照WGS-84模型转换为地理位置和速度.Matlab仿真与嵌入式系统运行结果表明设计的组合系统结构简单,稳定性好.避免了传统GPS/INS组合导航算法,要求惯性传感器精度高,计算量大,耗费硬件资源多的问题.     

卡尔曼滤波在无人水面艇双天线GPS定位测向系统中的应用

针对无人水面艇双天线GPS定位测向系统的定位误差问题,利用卡尔曼滤波算法对GPS数据进行滤波处理;根据位置与速度及航向的关系,建立数学模型,然后利用卡尔曼滤波算法对定位测向系统的测量值进行滤波处理;首先,对无人水面艇在静止、低速及高速运动状态的GPS数据进行了处理;仿真结果表明,在这三种情况下卡尔曼滤波方法能够提高GPS定位精度,在定点实验中观测值的均方误差为0.5259,滤波后变为0.0536;最后,在干扰情况下的无人艇运动仿真实验中,经过卡尔曼滤波后测量数据的均方误差由0.5043降低为0.3553;实验说明卡尔曼滤波能获得很好的滤波效果。     

机动车视频测速中关键技术的研究与实现

针对通过视频检测机动车行驶速度方法精度低、易受阴影十扰和无法对多辆机动车同时测速的问题,该文介绍了一种基于机动车视频测速模型检测机动车行驶速度的新方法。基于该测速模型实现的机动车视频测速系统取得了令人满意的测速效果,在一定条件下其视频测速精度可达到98．33％。     

升级数据无处不在——先知智能行车安全预警仪测试报告

正行车安全预警仪俗称电子狗,是一种汽车驾驶专用车载装置,由于我国交通环境复杂,能够针对国内的流动测速进行预警,固定警示点和流动测速点的预警整合是当下市面上流行的二合一预警一体机,因此行车安全预警仪成为车主们必备的车载电子产品。而行车安全预警仪分为普通行车安全预警仪和智能行车安全预警仪。行车安全预警仪是通过GPS标注需预警示点的坐标(可以是学校、路段、摄像点、桥梁、隧道等),并形成数据库。存储在车载的行车安全预警仪中,行车安全预警仪内置GPS定位系统,可以检测车辆的行驶速度和方向,内置程序自动检测车辆的行驶速度和方向与数据库中的警示点坐标核对,当程序检测到车辆在以特定速度靠近某警示点时只要方向和速度或其他预先设定的条件满足,预警仪就会提示车主。车主配备了行车安全预警仪之后,可以有效防止超速等违规现象发     

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。