基于FPGA和NIOS的惯导组件测试系统研究

针对惯导组件产品测试中多种信号输出的测量需求,设计了一种基于FPGA和NIOSII软核的双模式惯导组件数据采集系统。该系统以FPGA和USBCY7C68013芯片为核心,实现对4个惯导组件输出的48路脉冲进行频率计数和对8个惯导组件输出8路串口数据的接收,最后通过USB芯片将采集得到的数据上传至测控计算机,并由计算机进行保存、处理和显示。该设计降低了采集电路复杂度,提高了产品测试效率和采集系统的可靠性、稳定性。     

基于LabVIEW和FPGA的模拟信号源设计

介绍了一种基于PC 机、FPGA 和数字频率合成技术（DDS）的隔离型任意波信号发生器的设计方法;利用LabVIEW 虚拟仪器设计上位机软件控制平台,利用基于FPGA 的DDS 技术实现下位机硬件设计,通过局域网将软硬件平台连接起来构成具有64路有独立地线系统的模拟信号源,输出频率（DC）达8 kHz,幅度0～70 V。     

基于ARM的多串口数据接收系统设计

针对目前惯导测试系统只能测试一组产品的现状,设计了一种能实现4组惯导产品同时测试的基于微控制器LPC2368的多串口数据接收系统,以提高效率.在综合分析测试需求的基础上,通过对微控制器LPC2368软硬件的设计实现了四路串口数据的同步接收,并且使用USB总线将四路串口数据通过中断传输的方式将数据实时快速上传至测控计算机.通过使用VC＋＋6.0软件的编写完成上位机应用程序的设计,实现了四路串口数据实时的显示、存储及标定.通过大量实验,并对得到的实验数据进行统计和分析,结果表明该系统实现了同步无错误接收四路串口数据的设计要求,具有很好的实用性.     

基于FPGA的并行DDS信号发生器的设计与实现

针对DDS(直接数字频率合成)电路的运算速度受相位累加器的累加速度和ROM读取速度的约束问题,采用多路并行和流水线相结合的方法改进了DDS电路的结构,有效地扩展了DDS电路的输出带宽。通过在FPGA内设计基于双DDS电路结构的信号发生器,用数字的方法直接实现了标准波形和各种调制波形的双通道输出。该方案结构简单,控制灵活,实验测试结果表明,该信号发生器能输出稳定、高带宽、高速度、高精度的信号波形。     

基于ARM和FPGA的旋转叶片振动信号仿真系统设计

设计了一种脉冲信号发生器,作为高速旋转叶片振动测量系统中的测试环节,实时模拟现场光纤传感器产生的多路脉冲信号,用以测试和验证上位机软件算法的可靠性.对旋转叶片进行数学建模,提取影响叶片振动的相关参数,计算出各传感器脉冲信号产生的时间;实现了基于ARM和FPGA的硬件方案,使用ARM进行外设的控制,使用FPGA进行主要运算和脉冲信号的输出.将该设备应用于叶片振动测量系统,能够产生准确的脉冲信号,完全满足系统高速、高精度的要求,通过自带键盘或串口输入参数,该设备具有足够的可调范围,且同时做到便携性.     

基于有限状态机的角度信息采集电路设计

利用编码器的光电信号转换功能,能够将天线角度信息转换为脉冲信号;编码器输出A、B、Z三相脉冲信号,用FPGA对三相信号进行接收,实现角度信息的采集;根据A、B相脉冲的特点,通过检测A、B相信号的电平变化,采用有限状态机的方法,产生辨向信号和计数脉冲信号,这种方法克服了由于脉冲干扰和天线抖动带来的影响;通过设计可逆计数器,实现对脉冲的积累计数;同时设计能够与串口进行通信的并行—串行数据转换电路,便于进行数据处理;设计锁存器,保证数据转换不发生错误;仿真结果证明电路有较强的抗干扰性。     

多通道捷联惯组数据采集系统

作为惯性导航的重要组件,惯性器件通常由陀螺仪和加速度计组成．为完成对其性能的评价,需要研制专门的数据采集系统来实现对其的测试工作．传统的惯组数据采集由于体积庞大,技术更新困难,可靠性差等方面的原因,越来越难于满足当前的测试需要．随着FPGA技术的快速发展,使得惯组数据采集系统越来越小型化和简单化．通过选用XILINX公司的XC3S1000—4FT256I芯片,实现了将惯组输出的陀螺仪脉冲信号、加速度计脉冲信号和温度传感器信号直接输入给FPGA进行处理,完成了脉冲数据的采集．经过在两轴转台上的实际应用,通过对大量测试数据的比对与分析,发现用本系统测试的惯组数据,其稳定性指标与传统方法相比,提高了近1σ．     

基于FPGA的智能化波形发生板卡设计

测试系统中的信号源是系统的一个重要环节,是准确反馈被测部件各项性能参数的关键.提出了一种基于FPGA的波形发生板卡,采用Verilog HDL实现FPGA内部逻辑电路设计,采用DDS算法实现波形频率.总线选择BLVDS,FPGA完成BLVDS总线上数据的接收、发送,以及数据的缓存,上位机指令和板卡反馈数据依照Modl3...     

基于FPGA的微传感器信号采集系统

为实现对微传感器输出的模拟信号进行实时采集和显示,提出了一种基于现场可编程门阵列(FPGA)的微传感器信号采集系统。系统由FPGA,24位高精度模/数转换芯片ADS1256和上位机构成。系统采用FPGA作为核心控制器,利用Verilog语言,对FPGA的普通I/O口进行编程,模拟串行外设接口(SPI)总线规范的信号时序,完成ADS1256的读写操作控制。通过RS—232串口通信将采集到的数据送入由Visual C++开发平台编写的上位机中,最终实现微传感器输出模拟信号的实时采集、显示和数据保存等功能。通过采集标准直流电压信号进行测试,测得采样误差小于0. 03%。     

基于FPGA和单片机的多路信号光纤传输系统设计

基于FPGA和单片机技术,设计了多路信号光纤传输系统,利用单片机实现了模拟数据的高精度采集和通信信号的双向传输,利用FPGA实现了多路复杂信号的处理与传输;实验证明:该系统不仅能传输多路模拟与数字信号,以及低速数字信号与高速脉冲信号,还能实现双向CAN通信;与现有光纤传输系统相比,多路信号光纤传输系统不仅实现了多路复杂信号的采集,而且使用一根光纤实现了大容量多数据的双向传输,一方面减小了产品体积,另一方面降低了产品成本。     

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.