火焰触发器用自适应信号处理电路设计

为解决火焰触发器无法依据天空背景亮度自动调整电路增益,易于出现信号饱和和无信号输出的问题。基于乘法除法运算原理,本文设计了一种新型前馈型AGC电路用以扩大火焰触发器的动态范围。输入信号经峰值采集电路、过峰时刻判断电路、峰值保持电路、除法电路后生成增益控制电压,增益控制电压与经延时的原始信号相乘,实现对输入信号的自适应放大。经模拟实验验证,该电路可有效将80mV~1V范围内的模拟信号放大至5V,电路动态范围15dB~35dB、延迟时间100μs,输出信号信号幅值波动较小,最大误差小于5%。     

K类音频功放的防破音控制系统

设计实现了一种可用于K类音频功放的防破音控制系统,通过自动检测输出削波失真调整系统增益,确保K类音频功放在较大的输入动态范围内,输出音频信号光滑无失真。确保K类音频功放在整个工作电压内保持低谐波失真,且保持恒定输出功率。采用0.5μm CMOS工艺实现了集成这种防破音控制系统的2.0 W单声道K类音频功放。测试结果显示,在3.3 V~4.2 V电源电压范围、增益设置为24 d B、4Ω喇叭负载下,该K类音频功放能够在0~1.2 V_(rms)的动态输入范围内保持低谐波失真(THD+N)<0.5%,恒定无削波输出功率2.0 W。     

飞思卡尔智能车电磁导线的宽压检测方案

飞思卡尔智能车竞赛电磁组中,车辆要检测赛道中心通有交变电流的导线所产生的磁场进行路径识别。本研究以实验室原本电磁信号检测方案为基础,对其进行改进,使放大后的信号幅值可在0V~12V范围内变化。放大后的信号即使超过5V也不会失真,电感接近中心线时,直流电压值变化更明显。     

基于DSP和ARM的自适应振动信号采集系统

本文提出并设计了一种能够实现增益自适应功能的振动信号采集系统,该系统采用数字信号处理器（DSP）及嵌入式处理器（ARM）。该系统特点是能够根据被测信号的幅值变化自动调节放大器的增益,因而使得系统具有较广泛的适应性。同时利用SPI接口进行DSP与ARM之间的通信和数据传输,实现了高动态范围振动信号的高速采集。     

一种恒跨导满幅CMOS运算放大器设计

针对满幅运算放大器输入级跨导不恒定和简单AB类输出级性能较差这两个问题,采用两路结构相同的最小电流选择电路来稳定输入级的总跨导;浮动电流源控制的无截止前馈AB类输出级减小了交越失真,实现了运放的满幅输出;该电路采用0.6μm的BiCMOS工艺设计;利用Hspice进行仿真验证,结果表明,在0～3V输入共模范围内,输入级跨导的变化小于3.03%,开环增益94.7dB,单位增益带宽为7.2MHz,相位裕量为65°.     

基于潜标的水声信号数据采集系统

海洋潜标需要配有低噪声、低功耗和高增益的数据采集系统来对微弱的水声信号进行测量,建立了一套可以实现水声信号采集、处理、存储及分析的海洋潜标数据采集系统,对其等效输入噪声、功耗、增益等指标进行了测试,并结合海试声弹试验验证了其可行性.结果表明:该系统信号调理电路的等效输入噪声为4 μV,与传感器最小输出电压相近;系统总功耗为1.2W;系统增益为60 dB;4路信号调理电路具有较好的幅值、相位一致性.     

自适应数据采集与重构算法仿真研究

针对固定采样周期和输入输出增益的动态信号数据采集观测失效问题,以二阶系统的阶跃响应过渡过程为研究对象,提出了一种采样周期和信号增益自适应数据采集与重构算法,能够根据实时系统的结构参数自动调整采样周期、数据采集输入调整倍率和数据重构输出匹配倍率,从而自动适应信号幅值和过渡过程调节时间的变化,实现有效观测.设计了自适应数据采集与重构MATLAB仿真程序,并借助一组具有代表性的检验试样运行验证了这种算法的正确性.     

窄带阻抗匹配下信号传输的偏差控制仿真

窄带信号传输偏差控制是提高信号传输速率和满足大众需求的关键技术,针对当前相关研究成果存在实现后系统运行稳定性控制效果有待优化的问题,提出基于判决反馈的窄带阻抗匹配下信号传输的偏差控制方法。通过窄带信号抽样定理,利用降低采样频率实现窄带阻抗匹配下信号采集,根据采集到的信号,考虑到偏差通常在各种干扰下产生,设计并构建双环判决反馈下自适应滤波器,在偏差控制中,设定系统含有直扩部分,抑制信号传输中的干扰,并以减少信号失真为目的,引入判决反馈电路,判决反馈系统根据传输信号码片获取干扰信号估算值,并将所得估算值当作参照输入至自适应滤波器中,利用参照信号和原始信号的直扩部分相关性减小,使判决反馈可以更好地对窄带阻抗匹配下信号传输干扰进行抑制,并减少信号失真情况,从而实现信号传输偏差控制。实验结果表明,所提方法可以很好地抑制各种干扰,实现了信号传输偏差的高效控制。     

基于幅值跟踪法的自动增益控制系统设计

为了实现信号幅值的自适应调整,设计了一种基于幅值跟踪法的信号自动增益控制系统,该系统主要由单片机、增益可控放大器、幅值跟踪电路、按键和LCD等组成。通过实时比较幅值跟踪电路获取的实际幅值和按键设置的期望幅值,系统利用算法动态地调整放大器中反馈电阻的大小,使输出信号幅值始终与期望幅值一致。实验结果表明该系统能实现放大器增益的自动控制,输出幅值误差小于1.5%,响应时间小于0.1秒,可应用于相关的信号处理领域中。     

具有未建模动态的时变关联系统的鲁棒分散自适应镇定

针对一类具有动态、静态关联项和未建模动态的时变关联系统,通过利用反推设计方法和σ-修正自适应律,研究了鲁棒分散自适应镇定问题．当时变参数的变化率及未建模动态的幅值分别在某些范围内变化时,证明了闭环系统的所有信号都有界,且每一个子系统的输出与系统参数的变化率有关．仿真例子验证了控制方案的有效性．     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

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。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.