卫星微振动测量系统双冗余CAN总线接口设计

在轨微振动测量系统是卫星平台与遥感系统有效载荷的重要星载设备,用于测量卫星在轨运行时典型位置的微振动加速度水平。针对星上总线接口及微振动测量数据传输需求,设计了一种高可靠性双冗余CAN总线。通过CAN总线硬件驱动选型、数字信号处理(DSP)与CAN总线控制器接口匹配、读写时序设计与分析、总线协议与数据约定分析、驱动层和应用层软件设计以及总线切换和容错设计等方法,实现了与星务计算机的高可靠性CAN总线通信,可满足微振动测量系统指令接收、工作模式切换、测量数据与状态遥测数据传输等功能需求。通过地面测试与在轨运行验证,该CAN总线接口设计满足星载通信网络的性能要求,具有接口简单、稳定可靠、实时性好的特点。同时,该设计也为解决高速CPU与低速通信总线外设间匹配、独立型与复用型地址数据总线器件接口设计及CAN总线在星载通信总线领域的应用难题提供了参考。     

基于CAN总线的通信系统的设计与实现

CAN总线是一种多主方式的串行总线。最初CAN总线被应用在汽车上,其目的是连接汽车上各个部件,并使其可以进行自由通信和控制。同时减少原始方法的复杂的布线,实现基于CAN总线协议的局域网通信。CAN总线局域网通信具有以下优点:具有高抗干扰性;具有较高的实时性;它应用简单,项目开发周期短。文中的工作是实现基于CAN总线协议的数据采集通信系统。通过利用CAN总线模块(Basic)实现单片机之间的基于CAN总线协议的通信。     

基于CAN总线的轮询通信系统设计

针对传统CAN总线通信系统基于仲裁发送机制所存在的通信通道易堵塞、实时性、可靠性差问题,设计了CAN总线节点轮询通信系统。系统CAN总线通信机制为采用主从控制下的节点轮询方式。最后,通过实验完成了CAN轮询通信测试,结果表明,CAN通信实时性高,整机运行稳定、可靠。     

基于CAN总线的通信系统的设计与实现

CAN总线是一种多主方式的串行总线。最初CAN总线被应用在汽车上，其目的是连接汽车上各个部件，并使其可以进行自由通信和控制。同时减少原始方法的复杂的布线，实现基于CAN总线协议的局域网通信。CAN总线局域网通信具有以下优点：具有高抗干扰性；具有较高的实时性；它应用简单，项目开发周期短。文中的工作是实现基于CAN总线协议的数据采集通信系统。通过利用CAN总线模块（Basic）实现单片机之间的基于CAN总线协议的通信。     

单片机的CAN通信节点及其与PC机的USB通信

介绍了应用PIC16F877和MCP2510实现CAN总线数据通信模块,模块内部采用SPI数据传输,并且利用FT245BL实现PC机与PIC单片机的USB接口通信,组成一个演示系统。给出了系统结构框图与软硬件设计思路,提出了一种具有高可靠性、实时性和灵活性的CAN总线通信网络的实现方法。     

基于CAN总线的现代小区楼宇通信

CAN总线是一种支持分布式实时控制系统的串行通信的局域网络。它具有高性能、高可靠性、实时性好、独特的优点。CAN总线已经广泛用于现代小区智能化管理,在楼宇通信、物业管理方面有着独特的优势。该总线的通信速率完全能达到整个小区实时系统的要求,并且出错率低,运行效果好。运用CAN总线独特的技术,提高了整个系统的可靠性,在整个小区的局域网通信中占有很重要的地位。鉴于CAN总线性价比高,安装维护简洁方便,能创造很好的经济效益,因而具有广阔的应用前景。     

CAN通信中位定时的容差分析研究

CAN总线以其高性能、高可靠性及实时性等特点得到广泛应用.然而,这些优越性能在一定程度上受到硬件电路设计的制约.通过研究CAN总线上数据传输的过程,剖析了位定时对硬件偏差的容差能力.研究结论对CAN总线通信系统的设计有一定的指导意义.     

基于FlexRay总线的分布式测控系统

介绍了一种高可靠性分布式测控系统设计,采用FlexRay网络作为现场测控网络.该总线采用时间触发方式,并具有数据传输速率高、可靠性高和实时性好等优点,它给工业领域监控系统中原有的RS485、CAN总线等通信方式带来了更新换代的可能性.研究了FlexRay总线技术的硬件结构和通信协议,利用飞思卡尔单片机MC9S 12XF512作为主芯片,实现了多节点间的通信,为FlexRay总线技术在分布式测控系统中的应用奠定了基础.     

基于CAN总线的三级智能火灾报警系统

针对大、中型智能小区的火灾防范的要求,利用CAN总线,设计和开发了一种基于CAN总线的三级智能火灾报警系统.系统由用户端自动报警器、区域控制器、中央控制器和主控计算机四个部分组成,采用三级控制的方案,即采用两极CAN总线和一级RS-232总线作为通信网络.通过在虚拟住宅环境下测试,系统通信能力强,实时性好,高可靠性.同时该系统还具有便于联网以及便于扩展等优点.     

一种高可靠与实时性CAN总线通讯网络的设计

针对现代汽车电子系统中电子控件众多、通信复杂度增大的现状,设计了一种高可靠与实时性的汽车电子系统CAN总线通讯网络,提出采用高、低速两条总线连接不同实时性要求的电子控制装置,有效的减少了可能的总线冲突,提高了关键系统的实时性;通过网关实现两个不同速率CAN网络之间的通信;设计了中心监控节点及基于PC机的中央控制系统;网络的数据链路层及物理层遵循CAN2.0B技术规范,实验结果表明本文所设计CAN总线系统在可靠性和有效性方面均有较大提高.     

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。