基于MEMS传感器微型飞行器航姿仪的硬件实现

针对微型飞行器(MAV)的特点介绍了一种基于微机电系统(MEMS)传感器的微型航姿仪,它包括三轴陀螺、三轴加速度传感器、三轴磁阻传感器和数字信号处理器(DSP).详细给出了系统整体方案设计和具体的硬件选型和接口设计,并对电路设计中的关键技术进行了说明.这种微型航姿仪具有体积小、重量轻、功耗低和工作可靠等特点.     

基于单轴速率转台的角速度传感器标定方法

针对传统的标定方法标定成本高且对北向基准的要求严格等问题,提出了一种用单轴速率转台作为标定设备的光纤陀螺捷联航姿系统标定方法。对光纤陀螺组合的误差进行建模,将光纤陀螺捷联航姿系统安装于单轴速率转台上,使光纤陀螺捷联航姿系统的3个陀螺轴向分别朝下进行标定实验,由此标定出3只光纤陀螺的零偏、标度因数和安装失准角共12个误差参数。通过对标定精度进行分析,验证了该方法的可行性,其标定成本低且不需要北向基准,具有一定的工程应用价值。     

基于DSP+CPLD的捷联航姿系统设计与实现

针对捷联航姿系统高精度、小型化、高可靠性的发展需求,文中研究并实现了基于DSP+CPLD导航计算机的光纤航姿参考系统,在导航计算机设计中充分体现了DSP处理器实时解算和CPLD控制信号的双重优点.系统软件可实现加电BIT、磁罗差标定、CRC校验的存储器自检、捷联航姿解算和模糊自适应内阻尼卡尔曼滤波等功能.通过大量的试验验证了硬件的可靠性和算法的有效性.样机实验结果表明基于DSP和CPLD导航计算机的捷联惯性航姿系统性能稳定,满足系统的精度设计要求.     

CAN总线在捷联航姿系统中的应用

提出了一种捷联航姿系统的方案设计.该捷联航姿系统基于德州仪器公司新型数字信号处理器TMS320C6713,解算出的航姿信息由CAN总线输出.较之于用传统的RS232、RS485、1553B等输出方式,使用CAN总线,有助于将航姿系统、计算机、控制设备、测试设备、各种传感器,通过CAN总线互连,构成一个高速、可靠、廉价的现场总线控制系统(FCS).     

基于DSP的小型捷联航姿系统的设计与仿真

针对以捷联惯导为中制导的战术导弹,设计了一种基于数字信号处理器（DSP）的小型数字化捷联航姿应用系统,并对捷联航姿系统的算法及器件误差补偿进行了分析与仿真。首先针对捷联航姿系统提出了器件误差的简化模型,然后通过对比四阶增量法和四阶龙格库塔法解四元数微分方程,提出了以四阶增量法为基础构建快速执行算法。最后采用一组实测信号对系统进行了仿真验证。结果表明,传感器的精度对仿真结果具有明显的影响,对惯性器件的实时误差补偿是非常必要的。所选算法的计算量与存储量都不大,在实际计算中可以选用。该系统具有运算速度快、精度适当等特点,不仅可用于小型战术导弹,也可用于其它低成本的小型导航领域。     

基于MEMS传感器的数字式航姿系统设计

针对传统的模拟平台式航姿系统的不足,设计并实现了基于微惯性传感器和微磁传感器的数字式捷联惯性航姿系统。结合四元数微分方程,利用一种以加速度计和磁航向为观测量的卡尔曼滤波器进行数据融合,实现了对陀螺漂移的修正。PC104作为导航计算机,安装了微软高性能嵌入式操作系统。实物静态和跟踪实验表明:该航姿系统简单可行,能够很好地满足航姿系统精度要求。     

基于MTi微惯性航姿系统的卡尔曼滤波器设计

本文介绍了惯性航向姿态系统中两种常用的航向姿态测量方法和MTi的组成,并以MTi微惯性航姿系统（微机械陀螺、做机械加速度计、三轴磁强计）为研究对象,构建航姿系统。给出了基于MTi的航姿系统的四元数卡尔曼滤波算法,并在卡尔曼滤波器中利用加速度计和磁强计计算的姿态角来补偿陀螺的漂移。仿真结果表明了该方法的有效性。     

基于磁阻传感器的航姿测量系统罗差补偿技术研究

针对磁阻航姿测量系统在实际应用中易受到周围环境中的软硬铁效应引起的罗差干扰导致其航向角精度较低的问题,本文在分析航姿测量系统罗差产生机理的基础上,建立了对应的罗差修正模型,同时在已知当地磁倾角和由捷联于测量系统中的加速度计提取的载体姿态信息的基础上,提出了采用超定线性方程组求最小二乘解的方法推导出罗差系数的标定补偿算法。最后利用设计的算法对系统进行误差补偿对比试验。结果表明,该罗差补偿算法是正确有效的,三轴软硬铁效应得到了有效的补偿并且航向角解算精度得到了显著提高。该补偿方法为后续的载体误差分析和补偿提供了理论参考,具有一定的工程应用价值。     

基于DSP和STM32的航姿参考系统设计

近年来,随着MEMS惯性传感器的快速发展,民用领域对姿态测量的使用也越来越广泛,航姿参考系统便显得尤为重要.基于DSP和STM32单片机,采用多传感器数据融合算法进行卡尔曼滤波作为航姿解算单元,设计并完成了航姿参考系统的核心部分.选用SGT320E型三轴多功能转台,在静态和动态环境下进行了数据的分析和验证.结果表明,该航姿参考系统能够满足小型化、低功耗和低成本的航姿系统的设计要求,适用于对精度要求不是很高的民用领域.     

基于DSC与MEMS的微型测姿系统研究

针对当前无人机航姿系统对GPS信息依赖严重的特点,设计了基于MEMS ADIS16405传感器和数字信号处理器（DSC）TMS320F28335的微型惯性测姿系统。以MEMS传感器的角速度、重力加速度、航向信息,建立姿态四元数方程,解算出飞行器姿态。运用扩展卡尔曼滤波方法,消除MEMS陀螺漂移误差。DSC28335的硬件平台实现了四元数扩展卡尔曼滤波算法。转台仿真试验表明,漂移误差能在线最优估计和实时补偿,输出的航姿精度较高。该微型测姿系统具有较高的实用价值。     

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。     

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.