基于LS-SVM的开环光纤陀螺误差补偿方法

针对开环光纤陀螺标度因数是非线性的,而且随着输入角速度增大,光纤陀螺线性度误差也越大的问题,提出采用基于最小二乘支持向量机(LS-SVM)的分段误差补偿方法.以LS-SVM和直接近似法补偿误差大小为依据,确定分段门限值.采用实测转台上先纤陀螺VG941在全量程范围内的输入输出数据为训练和检验样本.结果表明分段误差补偿方法使光纤陀螺最大线性度误差由15%降至2‰,验证了方法的可行性和有效性,提高了开环光纤陀螺的精度.     

光纤陀螺捷联系统振动误差补偿研究

针对舰船振动环境对光纤陀螺捷联系统性能的影响,提出基于神经网络的非线性数学补偿方案。对加速度计信息作傅里叶分析,进行振动特征提取;利用提取的振动特征值作为输入向量进行BP神经网络训练,建立光纤陀螺误差输出模型;对陀螺进行在线补偿,减小振动引起的漂移误差,提高了捷联系统初始对准精度。     

光纤捷联惯导系统角加速度误差补偿技术

以实验室自行研制的光纤陀螺及其捷联惯导系统为基础,从光纤陀螺的传统标定模型入手,在进行角加速度补偿前,通过与转台激发出的角速度与光纤陀螺测量值做对比,得出系统在有大角加速度的情况下,光纤陀螺测量值与转台实际角速度值会有很大的误差,光纤捷联惯导系统姿态误差会在很短的时间内被放大。角加速度误差补偿后,在有明显角加速度的情况下,光纤陀螺能够准确测量转台的角加速度,捷联惯导系统解算精度明显提高。     

基于多模型模糊融合的MEMS陀螺补偿方法

为了实现微机电系统(MEMS)陀螺的高精度补偿,本文借助分段线性拟合与多模型模糊融合的方法,得到了一种新的标定补偿算法。通过对各轴分段组合的标定数据进行拟合建立多组补偿模型,并通过角速率的隶属度函数的模糊加权实现多模型融合,得到随测量值变化的线性补偿模型,提高了陀螺输出补偿的精度。实验表明,该方法的补偿精度明显优于传统方法。其算法简单计算量小,易于在实际工程中应用。     

数字滤波在光纤陀螺数据处理中应用研究

光纤陀螺以其全固态、无转动机构、高集成性,较宽的动态测量范围等优点逐渐成为陀螺发展的趋势.光纤陀螺所敏感的角速度信号中包含有各种噪声误差,如何对光纤陀螺输出信号进行处理以满足不同的工程应用要求是目前研究的关键问题.本文对中低精度的光纤陀螺在运动条件下的测量信号进行滤波处理,通过实测数据的应用验证,该方法能够有效减小信号方差且能保证滤波信号实时性.     

基于AR模型的MEMS陀螺误差补偿方法研究

针对MEMS(Microelectro Mechanical Systems）陀螺具有成本低、体积小但误差较大的问题,探讨MEMS陀螺的误差补偿方法。基于AR模型方法,采集MEMS陀螺原始信号,对原始信号进行预处理,利用预处理后的数据建立陀螺的AR(Auto Regressive)模型,辨识出模型参数。利用该模型对陀螺信号进行误差补偿,计算出陀螺的较精确值。通过对某MEMS陀螺误差补偿的静态和动态试验表明,提出的方法能够有效地减小误差,提高陀螺的测量精度。     

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。     

基于光纤陀螺仪的信号补偿

光纤陀螺仪是目前广泛使用的一种惯性仪器, 但在使用过程中仍然会遇到有很多问题. 光纤陀螺仪在使用过程中由于光纤陀螺仪内部元器件构造、材料的使用、以及元器件的精度等因素, 会产生一些误差, 如启动温度、零漂、刻度因子等. 同时在使用的过程中受外界的环境干扰也会使光纤陀螺仪产生误差, 如受外界的振动, 环境温度变化等. 通过分析研究光纤陀螺仪的原理和输出信号, 建立误差补偿模型, 对误差进行补偿分析. 应用分段平均选点法补偿了由于温度变化在信号中产生的线性趋势项, 以及使用平滑滤波算法对光纤陀螺仪输出信号进行     

光纤陀螺误差的实时建模与补偿

通过对干涉型光纤陀螺误差来源及其影响因素的分析,建立了与温度变化量及温度变化速率相关的角速率误差概率密度函数,并提出一种针对慢时变与弱非线性随机过程的分段等概率误差补偿方法.该方法采用非线性手段,对一系列具有统计平稳性的随机过程进行参数估计与预测,能够实现模型动态跟踪,近似程度较高,且充分发挥了并行计算的优势,可避免由补偿过程所造成的输出时间滞后.几种典型工作状况下的实际补偿结果表明其能有效地减小角速率及航向角误差.     

小波分析法在光纤陀螺随机误差补偿中的应用

光纤陀螺随机漂移是惯性导航系统产生误差的重要因素。尽量降低陀螺仪的漂移率是进一步提高惯性导航系统精度的重要途径,也是保证光纤陀螺静态误差补偿精度的前提。从抑制光纤陀螺随机噪声的角度出发,利用小波分析法对光纤陀螺的静态输出进行滤波处理,通过对比滤波前后陀螺的输出曲线、标准差以及各项随机误差系数,能够看出:该方法有效地补偿了光纤陀螺的随机误差。     

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。     

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.     

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     

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.     

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.     

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.