温度检测系统的非线性动态补偿研究

在温度测控系统中,对于温度传感器在测量时存在较大非线性动态偏移误差,提出基于参考模型的利用扩展卡尔曼滤波算法设计温度传感器的动态补偿的方法.用扩展卡尔曼滤波进行补偿器的参数辨识,从而得到比较精确的补偿器,因此温度传感器的动态偏移误差得到自动补偿.本文所设计的系统可以对温度进行有效的控制,且具有一定的鲁棒性和较好的响应速度.     

基于逆模型的温度传感器动态补偿方法

在瞬态测量中,温度传感器的测量滞后会影响到测量系统的精度。提出了一种通过建立温度传感器的动态逆模型来扩宽其工作频带,以此来减小因温度传感器测量滞后所形成的动态测量误差的补偿方法。用该方法设计的动态补偿器具有不依赖温度传感器动态模型的特点,可根据温度传感器和参考模型对输入激励响应的实测数据,通过微粒群(PSO)算法的优化学习得到补偿器的参数。检测信号经补偿计算后输出,能够克服传感器的测量滞后。实验证明了该方法的有效性。     

温度传感器动态性能测试技术研究

针对温度传感器的动态性能研究问题,本文介绍了对瞬态表面温度传感器进行动态校准的系统的原理框图、组成装置以及实验结果,并探讨了动态补偿的方法。动态测试结果验证了方案的可行性,表明本系统稳定性好。测试结果对热电偶温度传感器的研究和应用具有一定的参考价值。     

瞬态表面温度传感器动态建模方法研究

测量瞬态高温时,由于传感器自身的热惯性,测量结果与真实结果之间存在很大的动态误差.动态补偿或动态误差修正对于改善测温系统动态特性,减小动态误差有重要意义,而建立温度传感器动态数学模型则是进行动态补偿或动态误差修正的前提.本文首先设计了瞬态表面温度传感器动态校准系统;然后,利用系统所测得输入输出数据,采用系统辨识方法建立了测温系统的动态数学模型;最后,利用交叉检验法验证该模型的正确性.经检验该方法可以达到理想的辨识效果,从而为系统反滤波动态误差修正奠定了基础.     

某型航空发动机的温度传感器惯性补偿研究

针对某型航空发动机温度传感器的测量滞后问题,提出了传感器的惯性补偿方法.该方法首先求得时间常数,并采用最小误差原则对时间常数进行修正,然后将时间常数写入补偿环节,最后使用二次指数平滑法对补偿曲线进行修正.通过仿真与实验验证,求出了时间常数并实现了温度补偿,表明该方法是有效的,能够用于温度传感器的惯性补偿.     

基于复合RBFNN的数字温度传感器误差补偿方法

数字温度传感器存在零点误差与非线性误差,需要进行误差补偿.提出了一种复合径向基函数神经网络(CRBFNN)的数字温度传感器误差补偿方法:首先根据数字温度传感器的误差特征,构造两个相互独立的子RBFNN网络,获得两个独立的冗余补偿值;然后根据特征阈值、数字温度传感器的输出估计器和权值调节器,获得复合RBFNN输出融合权值...     

基于改进SPSO-BP神经网络的温度传感器湿度补偿

针对在实际使用中湿度影响温度传感器准确性的问题,通过对基本粒子群算法的分析,得出不受速度向量影响的简化粒子群算法,同时采用线性递减惯性权重,提出了一种改进SPSO-BP神经网络温度传感器的湿度补偿方法.通过改进的简化粒子群算法的不断迭代,优化BP神经网络的权阈值,直到得到最优权阈值,并赋给BP神经网络.根据湿度影响实验中测得的数据,运用此方法建立湿度补偿模型,与BP神经网络方法对比分析.结果表明,改进SPSO-BP神经网络的模型结构简单、补偿精度高,收敛速度快,有效地对温度传感器进行了湿度补偿.     

虚拟未建模动态补偿与数据驱动的非线性广义预测控制

针对一类离散时间非线性动态系统,把常规广义预测控制与数据驱动控制相结合、反馈控制与前馈补偿相结合、信号补偿与调节器原理相结合,提出了一种数据与虚拟未建模动态及其增量补偿的非线性广义预测控制方法.推导了闭环系统的输入输出动态方程,并分析了所提控制算法的性能.对比实验的研究体现出本文所提控制算法的优越性和有效性.     

克服温度传感器测量滞后的预测补偿算法

由于温度传感器的测量滞后,导致温度控制系统中的实际被控温度存在较大超调,本文提出的预测补偿算法,采用两支同一型号的热电偶,同时测量某一温度,其检测信号经补偿计算后,能够克服传感器的测量滞后,实验证明了该方法的有效性。     

一种新型的串联型有源电力滤波器

为了消除基波磁通补偿(FMFC)有源电力滤波器(APF)的控制延时,提高APF的电流跟踪性能,提出了采用基于预测电流补偿的新方法.建立了基于预测电流控制的基波磁通补偿有源滤波器的数学模型,采用离散化的方法预测下一周期参考电流值,实现APF电流的预测控制.这种控制方法可以消除采样、计算等带来的延时,具有开关频率固定、电压利用率高、开关损耗小、动态响应快等优点.最后,在此基础上搭建了实验平台,仿真与实验结果证明了将预测电流控制方法应用于基波磁通补偿有源滤波器的有效性和可行性.     

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.