太阳能水体净化装置的最大功率点跟踪器设计

简要介绍了采用太阳能作为能源的水体净化装置和光伏电源系统的特性及最大功率点跟踪的基本原理.提出了一种采用干扰观测法配合Sepic拓扑的斩波电路实现太阳能电池最大功率点跟踪控制方法,即将太阳能电池和Sepic斩波电路作为一个整体,直接根据检测到的电池功率变化来控制Sepic电路的占空比来跟踪最大功率点,这些改进使得系统简化.     

光伏发电系统中最大功率跟踪控制算法的研究和控制器的设计

本文对几种常用的最大功率跟踪控制算法进行比较,分析其优缺点,在扰动观察算法的基础上,提出了"变步长"扰动观察法改进算法,避免最大功率点的"误判"。并设计制作了最大功率点跟踪控制器的硬件电路,实现跟踪控制太阳能电池的最大功率点。通过最大功率跟踪控制实验,结果说明该系统可以有效地提高响应速度和跟踪精度,提高太阳能光伏发电系统的工作效率。     

基于滑模控制的光伏系统MPPT控制方案

结合光伏系统的工作原理和滑膜控制的特点,提出一种最大功率点跟踪(MPPT)控制方案。将滑模控制应用于该系统最大功率点的跟踪,包括改进变换电路,设计滑模变结构控制器。实验结果表明,该方案能快速跟踪太阳能电池的最大功率点,使系统稳定地工作在最大功率点附近,减小输出功率和电压的波动以及超调量,削弱滑模控制的稳态抖振。     

基于灰色预测扰动观察法的MPPT方法研究

为了提高光伏发电系统的输出效率,针对光伏发电现有扰动观察法的不足,提出了基于灰色预测扰动观察法的最大功率点跟踪方法。该控制方法根据负载功率的变化调节DC/DC电路的占空比来实现最大功率点跟踪,即通过建立GM(1,1)模型,对占空比步长数据序列的提取,预测系统未来发展趋势,确定相应的控制决策。在Simulink下进行了系统的建模与仿真,仿真结果表明该算法能快速准确地跟踪太阳能电池最大功率点,可以有效地提高光伏电池的输出效率。     

光伏系统功率优化器研究与设计

为了确保太阳能电池工作在最大功率点(M PP),提高光伏阵列的转换效率,研制了一种光伏系统功率优化器,介绍了系统的组成结构与工作原理.设计了降压斩波电路(BUCK电路)、驱动电路和采集电路等系统模块电路,建立了光伏系统功率测试系统,于静态和动态2种环境下进行性能测试,实验结果由测试上位机软件实时显示,结果表明:系统跟踪MPP的效率为99.38％,在2种情况下均能够准确、实时地跟踪MPP,且系统稳定,检测结果精度较高.     

光伏发电系统最大功率点跟踪的常用控制方法

最大功率点跟踪是光伏发电系统的重要问题。在对太阳能电池输出特性曲线分析的基础之上,阐述了光伏系统四种常用的最大功率点的跟踪方法。文章总结各种方案的优缺点及适用范围。     

DSPIC30F4011的模拟光伏并网发电系统

为了满足模拟光伏并网对于频率相位相同的基本要求,且具有最大功率点跟踪(MPPT)和欠压过流保护功能,设计了以DSPIC30 F4011为核心的控制系统,结合简单的模拟电路和数字电路实现了太阳能电池的最大功率点、频率及相位的跟踪.逆变器采用SPWM控制方式,将直流电逆变为标准单相正弦波交流电.研究结果表明,该系统具有效率高、总谐波失真低、跟踪性能优异和保护完善的特点.     

光伏并网发电系统最大功率点跟踪算法研究

针对神经网络算法在太阳能电池最大功率点跟踪中收敛速度慢,结果容易陷入局部极小等缺点,提出了一种基于遗传算法优化神经网络来实现最大功率点跟踪的控制方法。该算法利用遗传算法具有全局搜索问题解的特性,通过选择、交叉、变异等遗传操作,实现了神经网络权值优化,克服了神经网络初始权值对控制效果的不利影响。实验结果表明：该算法提高了神经网络在最大功率跟踪中的收敛性与非线性逼近能力,在日照强度、环境温度变化时仍能快速、准确地跟踪到太阳能电池的最大功率点,具有较好的稳定性。     

基于遗传算法的最大功率点跟踪

最大功率点对于提高光伏发电系统的整体效率具有重要作用,对优化算法在最大功率点跟踪中的应用进行了研究。基于光伏发电原理,通过Matlab和S函数建立了太阳能电池的仿真计算模型。针对传统最大功率点跟踪方法自动跟踪速度与跟踪精度难于兼顾的问题,应用遗传算法建立了最大功率点跟踪模型。仿真结果表明,当光照强度、电池温度变化时,模型能够快速、精确地跟踪最大功率点。通过与爬山法的对比研究,表明在相同跟踪时间限定下,遗传算法具有更高的跟踪精度,具有良好的综合性能。     

基于STM32的太阳能多功能充电模拟系统设计

为解决太阳能的转换效率低和开发利用范围小的问题，本文设计了一种基于STM32的太阳能多功能充电模拟系统。该系统由STM32F1主控模块、太阳能电池模拟电路、电压电流采样模块、双向DC-DC变换器、Boost升压电路、隔离驱动电路、USB接口充电模块、红外遥控和LCD显示模块组成。通过STM32F1主控模块经光耦隔离驱动电路产生两路PWM波，两路PWM波各自闭环控制，以实现最大功率点跟踪和充电电压的稳定。实验结果表明该系统能很好模拟正常光照和弱光条件下太阳能电池的充电情况，且充电电压稳定，最大功率点跟踪与实际值偏差较小，还可实现红外遥控设定充电电压值和LCD屏显示充电电压和电流值情况等功能。     

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     

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.     

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。