Minimum switching control for adaptive tracking

The switching adaptive control method has been used for quite a few years to solve the adaptive stabilization and model reference adaptive control problems. However, a serious problem with the switching control method is that the number of ‘candidate’ controllers can potentially be very large, especially for multi‐input–multi‐output systems. In this paper, we consider a class of minimum‐phase multi‐input–multi‐output plants with some mild compactness assumptions. Given any polynomial reference input, we provide a switching control law which guarantees exponentially stability of the closed‐loop system with exponential tracking performance. The main contribution of the paper is that we give the minimum number of candidate controllers required for switching. In particular, the number is equal to 2 for single‐input–single‐output plants (one for each sign of the high‐frequency gain), and is equal to 2^m for m‐input–m‐output plants. That is, the number is independent of the degree and the relative degree of the plant. Copyright © 2006 John Wiley & Sons, Ltd.     

区域水资源模糊多目标规划模型及求解

针对区域水资源系统规划的多目标性和各目标的不精确性，建立了区域水资源系统模糊多目标线性规划模型。该模型改变了以往按确定性目标进行优化的思路，只需要给定目标值一个范围，就可以在规定的目标范围内进行优化求解。在求解过程中，建立了以各模糊目标隶属度值最大化为目标的模糊目标规划模型，采用目标隶属函数正负偏差量变量替换的方法，用线性目标规划的方法求解。经过实例验证，该模型求解比较简单，求解结果合理，与普通规划结果相比水资源模糊目标规划在规定目标的范围内取得了更好的优化结果。     

一种适用于高数据速率和高速移动环境的新型信道估计方法——双正交通道信道估计方法

本文给出了一种适用于高数据速率和高速移动环境下的新型有效的信道估计方法-双正交通道信道估计方法(CETOC,Channel Estimation by using Two Orthogonal Channels),这种信道估计方法通过采用两个独立通道的联合估计,可以有效的克服快衰落的影响,从而使得在快衰落信道下应用多维状态调制成为可能.     

主动阻尼控制中的扩展加速度输出反馈法

正位置反馈(PPF)是一种能够显著提高结构模态阻尼的控制策略，但是这种策略在原理和应用中具有一定的局限性。本文在指出了传统的PPF控制器的优缺点基础上，提出一种扩展的加速度输出反馈控制方法AOEF，同时给出了最优AOEF控制器的设计计算方法。仿真计算和实验表明，在传感器／作动器同相的情况下，采用这种控制器的闭环系统具有无条件的稳定性，在非同相的情况下也能达到优良的控制性能。     

NUMERICAL SIMULATION OF TIP-CLEARANCE FLOW IN CASCADE

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＴｉｐ ｃｌｅａｒａｎｃｅｆｌｏｗｓｏｃｃｕｒｉｎｖａｒｉｏｕｓｅｎｇｉｎｅｅｒ ｉｎｇａｐｐｌｉｃａｔｉｏｎｓｓｕｃｈａｓａｘｉａｌ ｆｌｏｗ ｐｕｍｐｓａｎｄｄｕｃｔ ｅｄｐｒｏｐｅｌｌｅｒｓ .Ｔｈｅｉｎｅｒｔｉａｌｆｏｒｃｅｓａｃｔｉｎｇｕｐｏｎｔｈｅｆｌｕｉｄｉｎｔｈｅｎａｒｒｏｗ ｇａｐｂｅｔｗｅｅｎｂｌａｄｅｔｉｐａｎｄｔｈｅｓｕｒｒｏｕｎｄｉｎｇｗａｌｌａｒｅｓｕｆｆｉｃｉｅｎｔｔｏ ｇｅｎｅｒａｔｅａｔｉｐｌｅａｋａｇｅｖｏｒｔｅｘｏｎｔｈｅｓｕｃｔｉｏｎｓ…     

多模复合制导数据融合器性能评估系统方案设计

从构建多模复合制导数据融合器性能评估系统的需求出发，详细介绍了多模复合制导数据融合器性能评估系统的构建方案，并从软硬件两个方面介绍了构建这样一个系统所需要注意的问题和解决办法．     

MEMS系统级设计与基于多端口组件网络的建模方法

MEMS的系统级设计对保证其整体综合性能和合理开发MEMS产品至关重要。针对MEMS的多能量域耦合、多信号混合的特点以及能量非保守等特殊要求 ,提出了基于多端口组件网络的MEMS系统级建模方法———采用多端口组件表示MEMS的功能结构部件 ,组件与组件通过端口联成网络表示整个系统 ;用统一规范化的微分代数方程表征并用硬件描述语言表述多端口组件。针对梁等具体的MEMS功能结构部件 ,采用宏建模方法确定其行为方程 ,从而得到有特定物理意义的、可供重用的组件模型。最后 ,给出了微加速度计的基于多端口组件网络方法的系统级设计示例     

用于泵浦固体激光器的激光二极管线阵的输出特性

从实验上测量了激光二极管线阵的输出特性,研究了温度、电流对输出功率、光谱特性,以及偏振特性的影响,为设计全固态激光器提供有益的参考。     

A Review of Wavelets for Digital Wireless Communication

Wavelets have been favorably applied in almost all aspects of digital wireless communication systems including data compression, source and channel coding, signal denoising, channel modeling and design of transceivers. The main property of wavelets in these applications is in their flexibility and ability to characterize signals accurately. In this paper recent trends and developments in the use of wavelets in wireless communications are reviewed. Major applications of wavelets in wireless channel modeling, interference mitigation, denoising, OFDM modulation, multiple access, Ultra Wideband communications, cognitive radio and wireless networks are surveyed. The confluence of information and communication technologies and the possibility of ubiquitous connectivity have posed a challenge to developing technologies and architectures capable of handling large volumes of data under severe resource constraints such as power and bandwidth. Wavelets are uniquely qualified to address this challenge. The flexibility and adaptation provided by wavelets have made wavelet technology a strong candidate for future wireless communication. Madan Kumar Lakshmanan was born in Chennai, India, in 1979. He received the B.E. (with distinction) in electrical engineering from the University of Madras, Chennai, India, in 2000. He joined the Indian Software firm, Polaris Software Labs Ltd., in 2000 where he wrote software for Telecommunication applications. At Polaris, he was awarded the “On The Spot Of Excellence Award” for his efforts. In 2003, he moved to the Indian Institute of Technology-Madras, to develop and establish a wireless communications network for rural connectivity. In 2004, he was awarded the Royal Dutch/Shell Chevning scholarship to pursue a Master degree in Telecommunications at the Delft University of Technology (TUDelft). At TUDelft he is affiliated to the International Research Center for Telecommunications-Transmission and Radar (IRCTR) where he is undertaking research in the field of wavelets applications in Wireless Communications. Homayoun Nikookar received his Ph.D. in Electrical Engineering from Delft University of Technology (TUDelft), The Netherlands, in 1995. From 1995 to 1998 he was a postdoc researcher at the International Research Center for Telecommunications-Transmission and Radar, TUDelft, where since 1999 he has been an Assistant Professor. Dr. Nikookar has done research on different areas of wireless communications, including wireless channel modeling, UWB, MIMO, multicarrier transmission, Wavelet-based OFDM and CDMA. He is a senior member of the IEEE.     

数字加速度传感器ADXL210在轨检仪中的应用

介绍了一种轨道检测仪及其重要传感器数字加速度传感器ADXL210的工作原理、功能、应用，并给出了ADXL210与MCS－51单片机的接口硬件电路和软件程序。