基于ARM的微型捷联惯导计算机设计

为了实现低成本小型制导武器的小型化和低成本化,设计了微型捷联惯导计算机系统;充分利用ARM器件和MEMS器件的微型化特点,以ARM嵌入式处理器为核心,MEMS微惯性测量单元为敏感器,构建了捷联惯导系统的硬件平台.根据捷联惯导系统原理,通过对姿态更新和位置速度更新算法的研究编写了硬件可执行程序;然后,进行了捷联惯导的定位和测姿试验;结果表明以ARM作为微型捷联惯导计算机满足了设计要求,系统稳定可靠.     

基于DSP的捷联惯导数据采集系统设计

针对捷联惯导系统对于精度和实时性等要求,介绍了基于DSP的捷联惯导数据采集系统的构成及技术实现.采用高速的DSP和CPLD设计了捷联惯导数据采集系统的硬件电路,实现了惯性器件信息的快速采集及其处理,从而满足复杂算法对于处理速度的要求,同时也提高了系统的集成度,实现了系统设计的小型化;设计了串行通信和显示模块,用于数据的交换以及实时显示;分析了系统硬件电路设计过程中可能存在的噪声干扰,并给出了相应的抑制方法.实验结果表明,各项指标均已达到了设计时的要求.     

基于惯性系的旋转式惯导系统快速对准算法

针对船舶大幅角晃动和线运动等复杂干扰,导致旋转式捷联惯导系统初始对准性能下降的问题,设计了基于惯性系的旋转式捷联惯导系统快速初始对准算法.针对旋转式捷联惯导系统的误差特性,设计了基于惯性系的粗对准方案;并提出了一种改进的罗经对准算法,达到缩短对准时间和提高对准精度的目的.仿真实验证明:该方法可以实现快速初始对准,7 min航向精度达到1.35′.     

航弹捷联惯导系统半实物仿真试验研究

某型远程航空弹药拟采用捷联惯导+卫星定位的制导系统.该制导系统中的捷联惯导系统姿态、位置解算精度和时延性将影响到控制系统的控制效果.为了测试捷联惯导系统的解算精度和时延性,该文设计了捷联惯导系统的半实物仿真试验框架结构,检验了捷联惯导系统导航计算机的解算性能.试验表明,捷联惯导系统的算法正确,解算精度和解算时延满足控制系统的要求,可以应用到航空弹药的制导与控制系统中.     

捷联惯导在轨标定算法研究

为了保证长期在轨工作的捷联惯性导航系统的精度,设计了一种捷联惯导在轨标定算法.通过分析捷联惯导的主要误差源,建立了标定误差模型和导航误差模型.用加速度计的零位漂移、陀螺仪的零位漂移、陀螺仪的标度因数误差和安装误差构造系统状态方程,利用卫星导航系统提供的速度、位置信息和星敏感器提供的姿态信息构造量测方程,经过滤波运算得到各项误差估计值.算法解决了捷联惯导与星敏感器坐标轴不重合的问题,提高了嵌入式计算机的计算能力.最后对算法进行了数学仿真,仿真结果证明了算法的有效性.     

双DSP结构的捷联控制与解算系统设计

设计了基于双DSP结构的捷联控制与解算系统.该系统以高性能的浮点处理器TMS320VC33作为捷联系统实时解算的核心,以TMS320VC5402作为通道控制、数据采集的控制核心.并结合FPGA的组合逻辑和时序逻辑,构成了高集成度的嵌入式系统.该系统具有采样速度快、浮点处理精度高、稳定性好等特点.可以充分满足捷联导航系统的要求.     

高动态环境下旋转矢量法的优化和应用

对于捷联惯性导航系统算法来说,姿态矩阵更新是算法的核心,但是锥运动环境是影响捷联系统工作的最恶劣条件,会诱导数学平台的严重漂移,最终导致算法发散,系统失效.提出了基于锥运动环境下,多子样旋转矢量的优化算法来补偿因锥运动引起的算法漂移,以及工程实现,比较了不同子样数目旋转矢量的优化结果.仿真结果表明了优化后的算法较之单子样,双子样算法有明显的漂移减小,较之优化以前的算法也有一定的改进,并且随着子样数目越多,优化后的算法精度也越高.     

高精度石英加速度计采集电路设计

从高精度捷联惯导系统加速度计信号采集需求出发,设计了一种高精度、低功耗、小型化的加速度计信号采集方案,采用数字补偿方案对转换电路的零位和标度因数温度系数进行了补偿校准,补偿后其全温指标提高了一个数量级.经实际电路测试验证,其在-55℃～+85℃温度范围内的标度因数全温变化小于0.5 ppm/℃,全温零位小于10μg,标度因数年重复性达到10 ppm,电路常温功耗仅为1.8 W,测试结果表明该电路方案满足高精度捷联惯导系统应用需求.     

基于ARM的多陀螺融合算法仿真研究

为最大限度地提高导弹捷联惯性测量组合的可靠性和量测精度,提出在捷联惯性测量组合中采用多惯性仪表(陀螺仪、加速度计)进行冗余配置,利用多传感器数据融合算法对冗余量测数据进行处理的组合方案,并在以ARM为核心构建的嵌入式系统仿真平台上对这些数据融合算法进行了仿真试验;仿真结果表明:冗余技术能够有效提高导弹捷联惯性测量组合的可靠性,同时利用多传感器数据融合技术可以明显提高导弹捷联惯性测量组合的精度.     

一种小型无人直升机捷联式组合导航系统设计

在基于小型无人直升机空中作业中,不仅需要导航系统提供的精确数据进行飞行控制,还需安装其它设备完成作业.为了减少小型无人直升机的负重,增加飞行时间,机载的导航系统需要高精度、低功耗、微型化的设计,采用微电子机械系统传感器的捷联式惯性导航系统满足了这些要求.然而惯性传感器的漂移会使捷联系统的数学解算产生误差累计,因而需要对惯性导航系统数据进行实时修正.本文设计了一种GPS修正的组合导航系统算法,应用卡尔曼滤波技术,对组合系统的多传感器进行数据融合,既保持了捷联惯导系统的自主性,又消除了累积误差,提高了组合系统的可靠性.上述系统通过在小型无人直升机飞行控制系统中的使用,验证了系统算法的有效性.     

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.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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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.