TDC-GP21电场式圆时栅传感器信号处理系统设计

针对时栅传感器信号处理系统需要高精度时间间隔测量的需要,设计了一种基于TDC-GP21芯片测量时间间隔的时栅信号处理系统.采用FPGA控制TDC芯片的高精度测量模式对整数部分时间脉冲进行计数,小数部分时间脉冲采用门电路延迟进行细测,使时间测量更为精确,从而提高了时栅位移传感器的分辨率;通过校准测量对测量结果进行补偿修正,减小了测量误差.实验结果表明:采用该系统后72对极的圆时栅在0°～360°测量范围内,传感器的原始测量精度达到±1″,分辨率为0.036″.     

基于二维细分技术的时栅信号处理系统设计

为了提高时栅位移传感器的动态性能及测量精度,提出了一种基于FPGA和二维细分技术的时栅位移传感器信号处理系统;利用二维细分技术对插补脉冲进行倍频处理,降低了对插补脉冲频率的要求,通过倍频后的高频脉冲插补时栅感应信号和参考信号之间的相位差完成了时栅角位移的测量,提高测量精度;该系统在FPGA内基于NiosⅡ软核完成数据的采集和处理,简化了系统,并加入自定义指令提高了数据处理效率;实验表明,采用该系统后,时栅位移传感器在960 MHz插补脉冲下测量误差峰峰值为士1.3",实现了时栅的高精度角位移测量.     

基于STM32F4的时栅位移传感器信号处理系统设计

为了提高时栅位移传感器的测量精度及分辨率,提出了一种基于STM32F4的时栅位移传感器信号处理系统;系统包括硬件电路设计和软件设计;硬件电路以STM32F4内核处理器芯片和复杂可编程逻辑器件CPLD为核心,集成了信号调理、信号处理等电路模块;运用高频时钟脉冲插补时栅位移传感器感应信号和参考信号之间的相位差,通过软件设计控制信号的采集和处理,实现了相位检测;经实验验证,采用以STM32F4为核心的时栅信号处理系统后,时栅位移传感器的角度误差峰峰值达到2.4”,实现了高精度、高分辨率的时栅角位移测量.     

基于Qsys的时栅信号处理系统设计与实现

为提高时栅传感器位移测量精度和测量分辨力,研究采用FPGA嵌入式锁相环倍频产生4路同频且相位差为45°的高频时钟脉冲作为测量基准,利用多路并行双边沿计数方法对时栅参考信号和时栅感应信号进行相位测量,通过相位差转换得到具有高分辨力的时栅位移信号, 采用Qsys开发平台设计Nios－II软核进行数据处理,利用傅立叶级数谐波修正技术对测量结果进行误差修正,提高时栅传感器的测量精度,在72对极磁场式时栅角位移传感器上进行精度测试,实验结果表明:经过误差修正后,该系统测量的整周误差从－57.2″~ 92.5″下降到－2.0″~2.5″,作为角位移传感器满足高端装备高精度定位需求,具有重要的工程应用价值。     

基于数字内插法的时栅位移传感器信号处理系统设计

为了提高时栅位移传感器的动态性以及测量精度,设计了一种基于数字内插法的时栅信号处理系统;利用粗计数法和数字内插法将时栅信号分成粗测和细测两部分分别进行测量,降低了对插补脉冲频率的要求,提高了测量精度;同时采用SOPC技术实现了系统电路的高度集成,并利用自定义指令提高了数据处理速度;实验表明,采用该系统后,时栅在40 kHz激励情况下误差为±1.2″,实现了时栅信号的高精度测量。     

高精度磁场式时栅传感器激励信号对测量误差的影响分析及系统设计

为提高磁场式时栅传感器测量精度,本文从理论上推导分析了时栅传感器激励信号源幅值和相位不一致产生的谐波成分对时栅传感器测量精度的影响,提出了一种基于DDS原理并采用完整闭环调节的高性能时栅激励信号源设计方案。以FPGA为微处理器,通过编程分频系统时钟,设置频率、相位控制字对DDS输出的信号频率、相位进行调节,使用增益控制器配合相位累加器实现相位到幅值精确转换。搭建了信号调理电路和信号反馈电路,通过实时对比反馈控制,解决了系统电路阻抗不匹配及干扰导致的激励信号相位不正交性和幅值不一致性的问题。实验结果表明：本文所设计的激励信号源输出信号幅值相对误差只有0.4%,正交性相对误差只有0.05%,并且采用该激励信号源,磁场式时栅传感器测角原始误差从±103.4"降低到了±20.3",有效抑制由于激励信号源幅值不一致和相位不正交带来的谐波误差。经修正后对极内角位移测量误差只有±1.3",整周角位移测量精度达到±2",满足高精度位移测量要求。     

基于电阻链移相的时栅高速测量方法研究

针对时栅位移传感器因频率响应慢影响测量速率的问题,提出了一种电阻链移相结合数据处理的方法.利用电阻链对时栅输出信号进行移相处理,采用多路模拟选择器和整形输出电路对移相后的信号分时输出,运用可编程片上系统(SOPC)技术进行数据处理和误差补偿.实验结果表明:采用该方法采样频率由原来的400 Hz提高到12.8 kHz,大幅度提高了现阶段时栅位移传感器的频率响应,使传感器实现了高速实时测量.同时能够有效地降低了随机误差,对极内的误差峰-峰值由1.5"降低为0.8",测量精度提高了近1倍.     

TDC-GP2在磁致伸缩传感器中的应用

为了解决在磁致伸缩传感器中时差测量模块精度不高的问题,系统采用高档8位单片机ATmega128控制高精度时间测量芯片TDC-GP2,实现了脉冲时差的精确测量.详细介绍了TDC-GP2在磁致伸缩传感器应用中的软硬件设计,给出了硬件电路原理图、软件流程图及关键代码,并对设计中的注意事项进行了说明.同时,软件采用数字滤波消除了随机干扰和脉冲干扰.该方案有效地实现了时差测量模块对前端信号的精确测量.     

一种新型的智能化位移温度测量系统

本文介绍了磁致伸缩位移传感器的工作原理,PIC16C63单片机的主要特性,以及核心器件TDC-GP1和DS18820的功能及使用方法,研制了基于PIC16C63、TDC-GP1和DS18820的数字式位移、温度智能化测量系统。该系统能同时实现多液位多点温度测量,并用RS-422或RS-485串行通信进行远距离传输,不仅测量精度高、而且稳定性好。作为新一代智能化传感器,该系统已完成试验,并投入试生产和推广应用。     

时栅位移传感器网络化接口设计

针对时栅位移传感器的“互联网+”战略,提出了一套时栅位移传感器互联网功能设计方案.以高性能的STM32F4微控制器为核心,设计了时栅位移传感器激励信号与感应信号的高速同步采样电路与网络接口电路,结合嵌入式操作系统,搭建了网络服务器模型,实现了时栅位移传感器的远程信号采集.实验结果表明,时栅位移传感器网络化接口模型能够准确地实现传感器远程信号采集,该模型的实现为下一步时栅位移传感器的大数据误差采样、误差远程自修正以及产品大数据分析提供了技术基础.     

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。