基于光纤微弯传感器的汽车动态称重系统设计

为解决目前汽车动态称重过程中存在的电磁干扰和精确度低的问题,在分析光纤微弯传感器测量原理的基础上,提出了一种基于光纤微弯传感器的汽车动态称重系统.压力的变化引起传感光纤发生弯曲变形,产生输出损耗,通过测量输出光强的变化实现汽车重量的动态称量;设计相应的光电转换和采样放大电路,并采用小波变换对采样信号进行去噪处理.对光纤传感系统的静态响应特性进行验证表明:在0～3 000 kg的范围内光纤传感系统具有良好的线性响应特性,灵敏度为3.8 mV/kg;动态响应实验表明:当汽车通过速度小于15 km/h时,光纤微弯动态称重系统的测量误差小于5.4%,能够满足动态称重的需要.     

测量叶尖间缝变化光纤传感器的研究

根据叶尖间隙测量的要求,设计了一种新型的光纤传感器。它采用了单光纤传光、多组光纤束接收散射光的结构。发射光纤位于中心,周围均布多组接收光纤,通过各组接收光纤光强的比值运算,消除了叶尖表面反射率变化对测量结果的影响,也可减小叶尖表面与传感器端面夹角给测量结果带来的影响。在转速同步传感器的配合下,该传感器可以实时测量所有叶片的叶尖间隙。当叶片转速在0~12000 r/min之间变化时,叶尖间隙的测量范围为0~3mm,测量精度为25μm。     

一种外骨骼机器人的光纤转角传感器设计

设计了一种新型的强度调制型光纤传感器,该传感器被应用于外骨骼机器人的智能感知系统,可以测量人体肢体的转动角度;采用双接收光纤光强比值法,并通过对光纤单元的并列排布设计,该传感器具备普通强度调制型光纤传感器的结构简单,性能稳定等优点的同时,能够实现对光源功率波动的自补偿,量程也扩大至0～180°。仿真结果显示,此种光纤传感器具有较好的静态特性。     

基于光强余弦分布的同轴型光纤位移传感器设计

在分析了发射光纤出射端光强分布的几种模型基础上,提出了光强余弦分布的假设,并据此建立了单光纤对数学模型,设计出用于叶轮泵转轴径向跳动测量的同轴型光纤束位移传感器,建立了光纤束传感器调制函数的数学模型,仿真分析了传感器的输出特性。对测试系统稳定性进行了动态测试,结果表明:在转轴转速保持5 000 r/m in时,5m in内其稳定性优于±10μm,满足设计要求。可见发射光纤出射端光强余弦分布假设与实际相符,对光强调制型光纤传感器的设计具有指导意义。     

叶端定时光纤传感器特性研究

为了探讨叶端定时光纤传感器的设计方法和设计依据,在实验测量的基础上建立了一个在高斯光束几何反射模型下的一维数值计算方法,可以在计算机上对叶端定时光纤传感器的特性进行计算分析,为叶端定时光纤传感器的优化设计提供了一个必要工具.对62.5/125多模光纤构成的19芯和37芯叶端定时光纤传感器的计算分析结果表明,传感器端面处的反射光斑半径在300 μm附近时有最佳的信噪比和接收光强波形;由发射光纤直接出射光束的19芯或37芯叶端定时传感器在与叶端的间距为1～3 mm范围内有较好性能;若用LD作为光源,37芯叶端定时传感器可以更好地的减少激光散斑的影响.     

线双折射对光纤光栅磁场传感器性能影响的理论分析

本文介绍了基于偏振效应的光纤光栅磁场传感器的工作机理。利用光纤光栅的偏振效应测量磁场可以克服以前传统测量磁场使用磁致伸缩材料不适合测量瞬态磁场的缺点,而且在传感头的设计上能够更加灵活。在传感头设计中,由于光纤本身存在的线双折射会对测量结果带来影响,为了明确双折射对光纤光栅磁场性能的影响,提高测量系统的准确爱,文中利用琼斯矩阵对光纤固有线双折射对传感器的测量特性的影响进行了理论推导和仿真分析,分别对稳态磁场和瞬态磁场受双折射的影响进行了仿真分析,为基于偏振效应的光纤光栅磁场传感器下一步实验研究提供了理论参考。     

磁浮列车间隙传感器动态特性研究

磁浮列车的控制和运行对间隙传感器动态特性有较高要求.首先,在研究磁浮间隙传感器动态性能与动态特性测试方法的基础上,根据磁浮列车用间隙传感器的原理,对传感器主要环节进行动态建模.接着,通过分析模型函数通解的结构形式,提取了影响传感器动态特性的影响因素,并对传感器动态特性进行了有效补偿.最后,设计了一种模拟开关方法,对传感器动态性能进行试验测试.分析与试验结果表明,传感器动态特性主要受检波电路影响,模拟开关方法可以有效地检测传感器动态特性.     

基于ZnO薄膜光学温变特性的光纤布拉格光栅传感器

ZnO薄膜具备吸收光谱的温变特性,可有效促进光纤布拉格光栅传感器的工作性能。因此设计了基于ZnO薄膜光学温变特性的光纤布拉格光栅传感器,选用高纯度的ZnO靶材在多功能多元镀膜系统,通过Haruo Takashashi构建计算模型,设计具有光学温变特性的光纤布拉格光栅传感器。其中温度传感头通过将制备好的ZnO薄膜镀于蓝宝石三棱镜斜边面上,结合蓝宝石三棱镜、凸透镜以及光纤面,加强光源利用率,实现光纤布拉格光栅传感器的设计。实验结果表明,所设计的光纤布拉格光栅传感器的波长漂移量会随着ZnO薄膜热膨胀系数不断提高而增加,ZnO薄膜等效折射率大的波长漂移量要比等效折射率小的低,对比多种传感器性能后,发现所设计的传感器温测范围广、响应时间短、测量精准度高。     

基于复合干涉原理的局部放电检测光纤传感器

针对基于传统干涉结构的局部放电检测光纤传感器存在参考光纤隔音处理难、不利于现场布设等问题,设计了Mach-Zehnder与Sagnac复合干涉结构的光纤传感器。本研究应用延迟光纤与直线型传感光纤结构解决了上述问题,采用3×3耦合器对光信号引入相移以增加系统的动态响应范围,并阐明了传感光纤以及延迟光纤长度对系统传感特性的影响规律。利用局部放电模拟装置进行性能测试的实验证明,所设计的局部放电检测光纤传感器具有良好的响应性能,测得局部放电信号的时域响应峰峰值为2.45 V,频率分布范围为10.62 kHz～57.73 kHz。研究表明该复合干涉结构可有效提升局部放电检测光纤传感器的检测性能,提高现场适应性。     

反射式强度补偿光纤角位移传感器研究

提出了一种基于三探头等间距排列结构的反射式光纤角位移传感器,实现具有强度补偿的大量程、高灵敏度角位移测量.理论分析了该传感器的强度补偿角位移测量机理,建立了数学模型得到角度传感调制函数的表达式;仿真分析了光纤探头端面距反射面距离h及探头旋转半径R对传感特性的影响;实验验证了单接收光纤角位移传感特性.结果表明:输出光强和角位移之间呈现较好的线性关系;距离h越大,传感灵敏度越高;R越小,灵敏度越低,但同时传感区间相对越大.     

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     

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.     

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.