一种三探头磁通门传感器的设计

磁通门技术应用于工程当中,主要为方向测量和磁场强度测量.国内磁通门技术应用于导航领域还比较少,我们设计了一种三探头磁通门传感器用于车体航向和姿态角的测量,详细介绍了三探头磁通门传感器的设计原理和测角原理.最后通过实验测量,并对传感器的测试结果进行了修正,达到了工程应用中对测角精度的要求.     

基于单片机的磁通门传感器非正交性校正研究

为提高对磁通门传感器误差校正的能力,该文提出基于单片机的磁通门传感器非正交性误差校正方法。构建磁通门传感器非正交性约束参数模型,结合PI调节器对磁通门传感器的节点进行部署设计;在输出振荡模式约束下设计磁通门传感器的组网结构,结合ZigBee组网协议实现传感器路由探测;在自适应反馈调节方法的约束下,结合最短路径寻优控制过程实现磁通门传感器非正交性误差补偿抑制,通过自适应扩频处理方法对传感器的信道输出进行补偿,并提取传输信道的关联特征量,结合信道均衡控制方法进行磁通门传感器网络的输出误差补偿;采用单片机对磁通门传感器校正过程进行集成控制,提高磁通门传感器输出过程的自适应信息处理能力。仿真结果表明,采用该方法进行磁通门传感器非正交性误差校正过程的稳定性较好、传输损耗较少,输出结果误码率较低,有效提高了传感器的信息输出的准确性。     

基于Maxwell与Simplorer仿真分析磁通门磁场传感器瞬态响应

为分析磁通门磁场传感器的工作原理,基于Maxwell和Simplorer软件建立了磁通门磁场传感器的电磁联合仿真模型,仿真了磁通门非线性激励电路中电流波形和磁通门传感器的瞬态响应过程,分析计算了磁通门二次谐波灵敏度以及磁通门传感器的转换系数.为验证仿真模型的准确性,利用钴基非晶薄片制作了磁通门传感器探头并利用开关电源驱动电路激励磁通门工作.实际测量的激励电流波形与仿真结果基本一致,磁通门二次谐波灵敏度的测量值与仿真值误差小于1.1%.测量磁通门的频率响应曲线得到磁通门的转换系数为100 mV/μT,与仿真值几乎完全一致,两者误差小于1.5%.该仿真模型对理解磁通门传感器的工作原理、瞬态响应过程以及指导微型磁通门传感器设计具有重要意义.     

运动状态下磁场模量修正技术研究

考虑到现有三轴磁通门传感器的修正存在方法复杂、对设备要求较高、效果不佳等问题.根据三轴磁通门传感器是由于三轴不正交、灵敏度不一致和零点偏移所引起的误差进行分析和理论计算,提出了三轴磁通门传感器修正模型并运用奇异值分解和单纯型法进行实验.实验结果表明,该方法能够简单、有效的对磁场模量进行修正,能够广泛的应用于三轴磁通门传感器静态和动态的总模量修正.     

新型测斜仪测量误差分析

在地下勘测,钻井探矿等领域,需要测斜仪对钻头的姿态进行精确定位与控制,实时监测地底下钻头的姿态变化。新型测斜仪采用环形双分量磁通门传感器和铁芯不固定的方法,具有结构简单,测量参数少,算法简单,正交度补偿算法简单等特点。但是新测斜仪在测量过程中,受到外界的误差干扰和内部传感器的安装设置误差等问题的干扰。本文针对新型测斜仪的传感器模型和电路设计方面,进行了新型测斜仪的测量误差原理分析,应用合理的电路设计减少电气间电磁干扰误差、应用了软件正交校正及物理校正的方法,有效的抑制了测斜仪传感器本身的姿态误差,提高了测斜传感器的测量准确度。     

基于SVR的三轴磁通门传感器误差修正研究

提出了一种基于支持向量回归机(SVR)的三轴磁通门传感器误差修正方法。分析和理论计算了三轴磁通门传感器中由于三轴非正交、灵敏度不一致与零点漂移所引起的测量误差;设计了相应矩阵形式的数学模型对该误差进行修正。构造新的目标函数,使修正模型的参数矩阵转换为等价的线性形式,从而建立起中间模型。再由SVR算法辨识出中间模型系数,并通过中间模型系数与参数矩阵之间的关系,实现对误差修正模型的辨识。用实际地磁场测量数据进行测试,结果表明:三轴磁通门传感器在不同姿态下的测量误差由800 nT修正到60 nT以下。该研究为提高三轴磁通门传感器性能提供了一种可行方法。     

一种迟滞时间差型磁通门检测方法

针对现有的迟滞时间差型磁通门传感器检测方法的不足,提出了一种对磁通门数字信号进行曲线拟合,检测峰值点对应的时间来计算迟滞时间差的方法。利用实验室自制的迟滞时间差型磁通门传感器对本文提出的方法进行测试,结果显示传感器在±10×104nT范围内线性度误差为±0.0026%,灵敏度为8.5nS/nT,多次测量子样标准差不大于0.05。实验结果表明,该方法能够减小现有检测方法产生的非线性误差和重复性误差,避免因阈值选取不当而造成的测量错误,具有很好的工程应用前景。     

三分量磁通门传感器轴定向问题研究

利用三分量磁通门传感器进行磁场测量时需知传感器的三个方向轴,而在传感器的安装工程中其三轴方向难于固定,这给磁场测量带来了不便。针对上述问题,从三分量磁通门传感器测量原理出发推导了传感器三轴定向计算公式和有背景干扰磁场时的轴定向误差计算公式;设计了三分量磁通门传感器三轴定向的仿真实验和物理实验,以实验数据为基础分析了背景磁场干扰源对磁通门传感器三轴定向的影响。研究表明:在高精度磁场测量中必须严格控制背景干扰磁场大小来减小传感器轴定向误差,所得结论对磁场测量有一定的实际指导意义。     

三轴地磁传感器误差建模及在线补偿方法

针对三轴地磁传感器的传统误差补偿方法操作繁琐、依赖外界仪器,无法应用于车辆地磁导航系统的缺点,提出了一种基于无迹卡尔曼滤波的三轴地磁传感器误差在线补偿方法。分析地磁传感器误差产生机理,得到了适用于车辆导航系统的地磁传感器误差模型。设计无迹卡尔曼滤波器估计模型中未知参数,从而实现误差的在线补偿。实验结果表明:所提方法有效可行,补偿后的精度在0. 5°以内,补偿效果较好。     

基于二次谐波脉冲幅值法的磁通门传感器

简述了磁通门现象的数学模型和工作原理。针对磁通门传感器在提高带宽时噪声也会随之增大的问题,应用二次谐波选择法设计了磁通门信号处理电路,试制了一种宽带低噪声磁通门传感器,很好地解决了提高带宽和降低噪声之间的矛盾。经测试,样机带宽可以达到700 Hz以上,10 Hz处的噪声小于10 pT/Hz,线性度为0.2%。     

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.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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