基于JCZ型传感器的扭矩和转速测量方法

讨论了基于JCZ型扭矩转速传感器的扭矩和转速测量方法;介绍了相位差检测电路,对相位差检测电路中各结点的信号波形和检测电路输出波形进行了分析;提出了基于P89LPC932单片机的等精度测量的信号处理方法,该方法有效地消除转速对扭矩检测的影响,提高了测量精度。     

提高变磁阻转速传感器信号幅度的方法

分析了影响变磁阻转速传感器的输出信号幅度的因素,提出了提高输出信号幅度的方法。理论分析和实验表明:将圆盘上的圆孔改为矩形孔,或者在圆孔中放置永磁体可以显著提高变磁阻转速传感器的输出信号幅度,从而改善传感器测量低速物体时的性能,扩大这种传感器的转速测量范围。     

磁电式双路输出转速传感器的研制

磁电式转速传感器是对电机转速进行检测的重要传感器,为保证传感器高可靠性地完成检测工作,研制出具有双路信号输出、波形近似正弦波的磁电式转速传感器。在一个骨架上,绕制出两组线圈,两组线圈同时检测电机旋转,输出信号具有高度的一致性,准确反应出电机转速。当其中一组输出信号发生故障时,另外一组输出还可以正常工作。通过对双路输出转速传感器的实际测试,这种双路输出转速传感器完全满足采集系统的需要。     

一种较大驱动电流的锑化铟磁阻式齿轮转速传感器设计

本文介绍一种采用锑化铟-铟共晶体磁敏电阻作为敏感元件的半导体薄膜型齿轮转速传感器，得出了传感器检测距离与磁阻输出信号的关系曲线。传感器驱动级采用推挽输出的形式，输出矩形脉冲负荷能力强，输出拉电流最大可达200mA以上，当温度在-℃30～ 70℃之间变化时，信号处理电路输出依然稳定可靠。     

基于GMR的可辨向齿轮转速传感器的研制

设计了一种可辨向的巨磁阻（GMR）齿轮转速传感器。该齿轮转速传感器同时利用两路巨磁阻芯片作为敏感元件,分别采集并处理在齿轮转动过程中引起的磁场扰动信号,然后通过单片机对这两路信号进行运算处理,即可获得齿轮转动的速度及方向。所研制的可辨向巨磁阻齿轮转速传感器具有高精度、测量间隙大、便于使用等特点。     

JCZ型转矩转速传感器输出信号的处理方法

为了测量转矩和转速,将转矩、转速信号通过JCZ型转矩转速传感器转换成两路正弦信号的电信号的进行测量;介绍了相位差检测电路,对相位差检测电路中各结点的信号波形和检测电路输出波形进行了分析,提出了基于P89LPC932单片机的等精度测量的信号处理方法;该方法有效地消除转速对转矩检测的影响,提高了测量精度;此方法已应用于某变速箱加载测试系统中,并且取得预期效果;实际应用表明,该方法的测量结果准确、稳定、可靠。     

基于VxD的发动机瞬时转速测量装置

基于VxD的发动机瞬时转速测量系统由磁电式传感器、信号调理电路、高速数据采集卡、PC及数据输出处理模块构成。调理电路将磁电式传感器产生的齿轮旋转逐齿脉冲信号调为矩形脉冲。VxD控制采集卡采集矩形脉冲，并将数据成组向PC传送。经程序运算得到每脉冲周期内的采样点数，瞬时脉冲频率和周期。     

汽车黑匣子速度信号采集电路的研究与设计

介绍了一种基于霍尔转速传感器的速度信号采集电路,电路主要为汽车行驶状态记录仪提供转速信号,通过对霍尔转速传感器信号进行放大整形,使处理后的信号转换成标准的方波信号。实际功能验证表明,该转速信号完全能满足汽车行驶状态记录仪的设计需要。     

基于磁阻传感器的宽量程转速测量电路设计

针对工程中高速宽范围转速测量需求,提出了一种基于磁阻传感器的宽量程转速测量方法。设计了转速信号调理电路,着重对实际应用中因磁场不对称、测量转速范围宽引起测量不可靠问题进行了分析和实验研究,最终,确定了转速信号调理电路参数,使得在最高转速达120 000 r/m in的条件下工作可靠,并成功应用于微型涡喷发动机控制系统。     

基于分布式控制的航空发动机智能转速传感器

依据航空发动机转速测量原理,提出并设计了一种基于分布式控制的智能转速传感器.分析了转速测量原理和软件采集实现流程,设计了传感器信号组合倍频调理电路与部分数字信号处理器(DSP)外围接口电路,编写了汇编程序.试验结果表明:该智能传感器测量精度高,误差小于0.02%,处理速度快,适用于航空发动机分布式控制试验研究.     

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。     

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.     

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。     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

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。