Erratum to "A note on overshoot estimation in pole placements"

There is a mild flaw in the statement of Proposition 2.1 in the above paper (cf.[1]).We restate it as follows.     

Erratum to “A note on overshoot estimation in pole placements”

There is a mild flaw in the statement of Proposition 2.1 in the above paper （cf. [1] ）. We restate it as follows.     

基于垂直载荷因子的增强型湍流检测方法仿真

大气湍流的存在严重影响航空安全。美国航空无线电技术委员会新修订的机载气象雷达最低性能标准DO-220A 增加了湍流检测的规范,要求检测量需考虑飞机特性的影响。基于该标准,研究了一种基于垂直载荷因子的湍流检测方法,并进行了仿真分析。首先,量化了飞机特性的影响,并同时考虑湍流谱宽,估计得出垂直载荷因子;其次,针对湍流检测门限,利用贝叶斯准则推导得出了基于统计特性的阈值确定准则。仿真分析验证表明:设计的增强型湍流检测方法能够满足DO-220A的要求,且能更准确地评估湍流对飞行的危害,对DO-220A 提出的增强型湍流检测规范具有重要的研究意义。     

一种模糊PID控制器的鲁棒优化设计

主要研究一种模糊PID控制器的鲁棒设计。以小增益定理分析得到该模糊PID控制系统稳定条件。针对参数摄动系统的‘最坏点’用该稳定条件作为约束,采用遗传算法对标称系统的性能进行优化,求得优化鲁棒控制器。同时对鲁棒模糊PID控制器中模糊非线性控制进行了比较分析。     

大跨度渡槽拱肋浇筑技术在工程中的应用

廖坊水利枢纽灌区二期工程工期紧,大跨度拱式渡槽拱肋混凝土浇筑作为制约工期的关键工序施工难度大.通过施工方案比较,拱肋混凝土采用分3次7块、纵横对称的浇筑技术,创新了大跨度拱式渡槽拱肋建造方式.此技术减少了拱肋混凝土浇筑过程中的混凝土温度应力和入仓混凝土荷载引起的模板支架变形,保证了拱肋同心圆度满足设计要求,确保了拱式渡槽的施工质量,具有较好的推广应用前景.     

Input to state stabilizability for parametrized families of systems

This paper studies various stability issues for parametrized families of systems, including problems of stabilization with respect to sets. The study of such families is motivated by robust control applications. A Lyapunov-theoretic necessary and sufficient characterization is obtained for a natural notion of robust uniform set stability; this characterization allows replacing ad hoc conditions found in the literature by more conceptual stability notions. We then use these techniques to establish a result linking state-space stability to ‘input to state’ (bounded-input bounded-state) stability. In addition, the preservation of stabilizability under certain types of cascade interconnections is analysed.     

A novel substrate integrated waveguide equivalent inductive‐post filter

A novel substrate integrated waveguide equivalent inductive‐post filter is presented and optimally designed by HFSS and equivalent circuit method. The filter is fabricated with a standard low cost PCB process. Measured data are in agreement with the simulated results. Excellent performance in selectivity, out of band rejection and passband insertion loss are shown. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

Nonlinear small-gain theorems for discrete-time feedback systems and applications

We derive in this work a local nonlinear small-gain theorem in the framework of input-to-state stability for discrete time systems. Our primary objective is to show that, as in the continuous-time context, these discrete-time nonlinear small-gain theorems are very effective in stability analysis and synthesis for various classes of discrete-time control systems. Two converse Lyapunov theorems for discrete exponential stability are developed to assist these applications. New results in stability and stabilization presented in this paper are significant extensions of previous work by other authors (IEEE Trans. Automat. Control 38 (1993) 1398; 39 (1994) 2340; 33 (1988) 1082).     

PID调节器参数的继电自整定方法

本文讨论了 PID调节器参数的继电自整定方法,它是利用继电反馈所产生的极限周期振荡来估计被控对象的参数,从而整定 PID参数。文中通过分析对象在继电特性作用下输入输出波形,推导了计算对象参数的公式。实验表明,本文所提出的整定方法简单、可靠,是一种有效的 PID参数自整定方法。