CAN节点通讯及处理的强度测试设计

随着现场总线技术的发展,CAN总线作为典型的现场总线之一,已得到广泛应用.针对CAN节点安全性、可靠性验证要求之一强度测试,给出了一个设计和实现,此设计的核心是一个具有USB2.O接口的双通道CAN总线实时数据转发器.通过高性能的MCU实现了实时CAN数据的收发,以及与主机之间的实时数据交换,用以检测被测CAN节点的数据收发和处理性能及设计余量,该转发器可以实现CAN连续帧的收发,帧间隙可以控制在几十微秒内.通过与主机测试软件协同工作,可对CAN节点进行强度和性能测试.另外若配置主机分析软件,也可以作为CAN双总线的协议分析仪,并且采用USB接口供电设计使用携带方便.     

CAN报文验收滤波原理及实现

由于CAN总线采用广播的传输方式,对于标识符不同的报文,总线上的所有节点均予以接收,如此以来各节点会接收并处理相当数量的无用报文,增加了系统软件的开销;通过CAN控制器对报文的验收滤波功能,从硬件层过滤掉了无用的报文,各个节点便可以针对不同的标识符而有选择性地接收来自CAN总线上的报文,从而降低了节点软件运行时的负担,阐述了使用ARM微控制器实现CAN报文验收滤波的方法,结合实际应用,较好地实现了CAN报文的验收滤波功能.     

燃料电池城市客车整车控制系统容错研究

为了解决燃料电池城市客车中安全性和可靠性问题,从车辆通信系统和整车控制器两个方面进行容错设计.本文设计并实现具有两条独立的CAN通道容错CAN节点,利用了CAN规范中的故障界定机制实现通道间的有效切换.整车控制器硬件设计采用两个微控制器,设计相应软件使其具有"失效安全"的能力.针对输入驾驶信号和部件信息,整车控制器进行故障诊断和处理,增强了整车控制器自身的故障诊断能力.最后,整车容错系统在整车控制器测试平台进行硬件在环仿真.试验验证了容错设计的有效性.     

基于CAN总线的自动气象观测系统设计

根据地面气象要素观测的需要,设计了一种基于CAN总线接口的自动气象观测系统,并详细介绍了该观测系统的总体结构设计和工作原理.系统采用主从方式,通过CAN总线将各个观测节点连接起来,并将各个观测节点采集的数据传输到上位PC机处理.观测节点采用MSP430单片机为主控制器,控制和处理传感器采集数据,并通过CAN控制器MCP2515将采集的数据传输给上位机.该系统硬件结构简单、可靠性高、测试结果能满足实际的测量要求.     

矿用新能源电机车CAN通信网络软件优化方法

针对矿用新能源电机车CAN节点发送错误造成关键信息丢失的隐患,在TTCAN协议的基础上提出了CAN总线发送容错方法,即对CAN节点发送失败的报文重新发送,当发送成功或者达到预设的最大重发次数后退出该报文的发送;给出了一种CAN总线高效接收、处理报文方法,在中断接收报文期间对报文进行缓存操作,同时修改接收到的报文数量,主程序以此为依据逐条对存放在缓冲区的报文进行后续处理,实现了报文接收与处理的分时操作。测试结果表明,该优化方法可有效提高CAN总线通信的实时性和可靠性,同时减小了各CAN节点CPU开销,提高了工作效率。     

基于CAN总线的侦察机器人控制系统设计

为了提高实验室现有遥操作侦察机器人的可靠性、实时性和可扩展性,设计了一套基于CAN总线的机器人控制系统.该系统由一个主节点和多个从节点构成,节点之间采用CAN总线相连,以实现侦察机器人各部分功能的模块化.给出了控制系统的总体结构,并结合系统中机械手控制模块阐述了CAN总线通信的硬件和软件设计.该控制系统已经成功应用在实验室现有的侦察机器人中,能够完成现场环境侦察和应急处理任务,在实际工程应用中得到了良好的应用.     

基于LabVIEW的CAN总线通信系统的设计与实现

介绍一种基于CAN总线的通信系统.采用两个CAN节点进行相互通信,这两个节点分别为自主研发的基于AT89C52单片机的CAN节点和瑞典Kvaser公司的CAN总线分析仪,并使用NI公司的LabVIEW软件设计上位机程序,成功地实现了CAN总线系统的通信.     

基于CAN/LIN总线的车身网络控制系统

对CAN(Controller Area Network)/LIN(Local Interconnect Network)总线做了详细介绍,设计了汽车CAN节点、LIN节点硬件电路,完成了CAN/LIN网关的硬件设计,LIN设计目标作为CAN的下层网络,同CAN相结合构成汽车分层通信网络结构.对车身网络控制节点软件进行了设计,该车身网络控制系统在网络通信中充分实现了数据共享.     

CAN网络层次化动态调度策略设计与实现

CAN总线是一种基于消息的事件触发通信服务,主要应用于汽车、机器人等实时通信系统.CAN总线上有多个节点互相独立工作,当多个节点访问总线时出现消息碰撞,由于CAN总线采用按位仲裁算法决定节点访问总线的优先级,导致低优先级节点访问失败,而高优先级节点继续传输消息,这种方式导致低优先级节点饥饿现象而丢失消息,因此CAN总线调度算法随之被提出.目前调度策略已从静态发展到动态,但是随着节点的增多,系统维护和调度难度增加,单条总线调度策略难以维持系统性能需要.因此本文考虑将系统中的节点挂载到多条CAN总线上构成CAN网络,针对CAN网络提出了一种层次化的动态调度算法,将节点优先级仲裁分为：单条总线本地优先级仲裁和系统全局优先级仲裁,确定系统优先级最高的节点,使其进行数据传输.利用MATLAB中的Stateflow工具,建立分层动态调度模型,依据CAN总线数据传输机制和仲裁机制,设计实现了节点模块、总线模块、函数模块等,在总线模块实现了两级调度.实验结果表明,本算法在增加了节点总数目的基础上,满足高优先级节点传输且避免了低优先级节点的饿死现象.     

基于CAN 网的模糊优先级配置策略

利用CAN网的广播特性,提出一种新的闭环模糊优先级配置策略.各节点数据优先级的设定既与其QoS需求有关,又与其节点标识位及前一个传输数据的优先级有关.该策略尽管使用较少的优先级,但仍能保证实时数据较高的可调度性和非实时数据的服务公平性.较少的优先级只占用较少的bit位,这样不仅扩大了CAN网的服务能力,而且提高了CAN网的带宽利用率.     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.