一种微惯性测量单元标定补偿方法

在介绍微惯性测量单元组成与结构的基础上,根据MEMS惯性器件的输出特性,建立了微惯性测量单元中加速度计和陀螺仪的数学标定模型,提出并推导了一种适用于微惯性测量单元的标定方法,该方法可以得到微惯性测量单元中惯性传感器的零位、标度因数、安装误差系数及g值敏感项等33个参数;然后,具体介绍了通过加速度计重力场静态翻滚试验和陀螺仪恒角速率试验对MIMU中参数标定的方法和步骤,并对实验室自研的MIMU进行了标定;最后利用得到的标定参数对测试结果进行了误差分析与补偿;实验结果表明,该方法使MIMU的测量精度提高了1～2个数量级,能够满足姿态解算及导航计算的精度要求。     

旋转弹用三轴加速度计安装位置误差标定补偿技术

针对旋转弹用捷联惯性导航系统中三轴加速度计在高转速下,由于安装位置不在一个点,三个加速度计测量的不是一点的比力,在角运动环境下姿态解算时产生动态误差的问题,提出了一种标定补偿三轴加速度计安装位置误差的方法。分析了动态误差产生的原因,在常规静态标定的基础上推导了动态标定的模型,高转速下的转台试验表明本方法能够很好的补偿三轴加速度计在高转速下产生的误差,有效地提高惯性测量单元姿态测量的精度,具有很好的工程应用性。     

捷联惯性传感器多余度配置的误差标定技术研究

对捷联惯性传感器多余度配置系统的标定技术进行了研究。详细分析了多余度惯性传感器各参数的测量原理及计算公式,针对典型的非正交配置(六传感器正十二面体)的多余度惯性测量单元(IMU),提出了一种简易的且具有较高精度的误差模型参数静态标定方法,给出了计算误差模型参数的数学推导过程和解析表达式。仿真结果表明:该计算方法精度较高,可以有效估计出多余度IMU的误差模型参数,提高了惯导精度。     

一种新型微惯性姿态测量系统的 系统误差补偿及标定方法

微惯性姿态测量系统机械精度不高、系统误差和随机误差干扰多样和传统标定计算复杂。针对这些问题,提出一种新型微惯性姿态测量系统误差标定的方法。通过对姿态测量系统的不同微惯性器件进行分析,有针对性的建立系统误差补偿模型。再设置实验转台给定系统不同速率及角度,最后利用最小二乘法、六位置标定法分别进行系统误差参数求解,经解算标定出零位漂移、刻度因子误差和安装误差角。最后通过标定前后对比测试实验,证明了该方法原理简单、易于实现,能较好地补偿微惯性姿态测量系统的系统误差,提高姿态测量精度。     

一种加速度计的标定补偿方法研究

针对微惯性测量组合(MIMU)中的三轴加速度计因为安装误差的缘故,会在恶劣的锥运动环境下出现误差发散问题,本文提出一种基于三轴位置速率转台的静态旋转多位置补偿标定方法.本文通过分析误差角补偿模型来设计相应的标定试验流程,然后利用非线性拟合的数据处理方法,准确计算出标度因数矩阵和加速度计电压.最后,经过标定试验和误差计算,与十二位置标定法对比发现,本文所设计的标定补偿方法能够将误差小一个数量级,能有效提高加速度计输出精度,具有重要的工程实践意义.     

基于椭球拟合的三轴磁传感器误差补偿方法

考虑现有多轴磁传感器的标定补偿方法普遍存在计算量较大、操作时间长、场地要求面积大、标定设备要求高等问题,提出了基于椭球拟合的三轴磁传感器误差标定补偿方法。在分析传感器误差产生机理的基础上,建立了磁传感器误差模型,推导了误差系数的解算公式,并利用椭球拟合的方法对三轴磁传感器进行了测试标定与误差补偿。实验结果表明,该方法能够正确、有效地标定补偿三轴磁传感器不正交误差、灵敏度误差和零偏误差,具有修正过程简捷、省时、精度高特点不依赖于精密仪器提供准确的方向基准、水平基准等,能够广泛应用于多轴矢量传感器的误差标定和有效补偿。     

一种基于磁传感器的MEMS陀螺标定方法

根据微型航姿测量系统各传感器的特点,研究出了一种基于磁传感器输出的MEMS陀螺标定方法,并根据MEMS陀螺误差参数模型设计相应的补偿算法,分别对MEMS陀螺的零偏和标度因数误差进行了补偿。与传统标定方法相比,该方法实现简单,适用于现场标定。实验结果表明,该标定方法能够有效地提高MEMS陀螺测量精度,补偿后陀螺在静态条件下2分钟内,俯仰角漂移小于0.035°,倾斜角漂移小于0.15°,航向角的漂移小于0.2°。当陀螺三轴均有角速率输入时,在角速度小于25°/s情况下误差都能保持在±2°以内。     

基于部分惯性传感器信息的单目视觉同步定位与地图创建方法

传统的单目视觉同步定位与地图创建(MonoSLAM)方法很难处理累积误差问题,如何有效地利用惯性传感器输出的运动信息辅助SLAM系统抑制累积误差是MonoSLAM研究中的一项重要内容.由于惯性传感器输出的三轴方向角中横滚角和俯仰角的精度较高,而偏航角的精度相对较低,如果在SLAM系统中直接使用惯性传感器输出的偏航角信息不但无法有效地抑制该系统中的累积误差,反而会进一步增大系统误差、降低SLAM系统的稳定性.针对这种情况,提出一种基于惯性传感器横滚角和俯仰角的MonoSLAM方法.首先利用惯性传感器输出的横滚角和俯仰角进行系统标定;然后将惯性传感器自身的偏航角作为系统状态向量的一个分量,利用扩展卡尔曼滤波器实时地估计状态向量,进而实现实时鲁棒的同步定位和地图创建.实验结果表明,该方法可以有效地抑制SLAM系统运行过程中产生的累积误差,并降低惯性传感器测量误差对SLAM系统稳定性的影响.     

捷联惯导系统加速度计标度因数和安装误差的试验标定

研究了捷联惯导系统惯性测量组合中加速度计标度因数和安装误差的标定问题。对捷联惯性测量组合中3路加速度计建立了输出模型,提出了在三轴转台上采用多位置试验对加速度计标度因数和安装误差进行标定的方法。实验表明,本方法能够有效地标定出惯性测量组合中加速度计的标度因数和安装误差,具有较高的精度,对提高捷联惯导系统的精度有着重要的作用。     

基于MEMS传感器的车载微惯性测量单元设计

为了感知汽车姿态,利用MEMS传感器自主设计了一种车载微惯性测量单元(MIMU),详细介绍了三轴MEMS加速度计、三轴MEMS陀螺和正六面体的设计。该单元具有成本低、精度高、体积小,且便于标定等优点,可以方便地运用到汽车姿态实时监测系统中。给出了单元的标定方法,分析了其误差来源,建立误差模型以及自主设计了标定系统。实验结果表明:该单元能有效地消除信号干扰,具有满意的精度要求,可对运用该单元进行汽车姿态监测等提供理论研究与工程应用参考。     

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.