刹车片减震胶的研制

讨论了高邻位酚醛树脂合成及其它助剂对减震胶性能的影响。研究试制出一种综合性能好的减震胶。     

基于HMS87C1408B的籽棉、菜籽和粮食水分综合测试仪

介绍了使用HMS87C1408B作为主控芯片的籽棉、菜籽和粮食水分综合测试仪的实现方法,重点说明了阻抗变换、软件驱动LCD和语音播报技术的实施.     

NEW TUNING METHOD FOR PID CONTROL OF A PLANT WITH UNDER‐DAMPED RESPONSE

In this paper, a tuning formula is derived for PID control of plants with under‐damped step responses. The under‐damped systems are modeled by second‐order plus dead time transfer functions. To derive the tuning rule, the dominant pole assignment method was applied to design the PID controllers for a variety of plant models. Then, the correlation between the controller parameters and the parameters of the models was found and the tuning formula derived. Several simulation examples are given to demonstrate the effectiveness and robustness of this formula.     

一类具阻尼非线性双曲型方程的初边值问题解的爆破

研究了一类具阻尼非线性双曲型方程的三维初边值问题,利用凸性方法给出了该问题的解在有限时刻爆破的充分条件,并给出了一个例子．     

μ-synthesis in H-infinity loop-shaping design

H∞控制理论中的回路成形设计和μ综合都已经是定型的设计方法．最近有文献提出一种将这两种设计方法结合起来处理弱阻尼谐振模态参数摄动的新方法．但是实际设计表明,二者的结合并没有达到预期的效果．本文分析指出,回路成形本质上是一种鲁棒稳定性设计,其H∞范数指标的逆就是系统的稳定裕度．而μ综合只是一种鲁棒性能的设计工具．μ综合与回路成形结合只是反映在稳定裕度上,而并不影响设计所允许的摄动大小．所以在回路成形设计中没有必要再加进μ综合法．文中附有算例．     

开关电源输入滤波器的设计

本文介绍了在开关电源应用中如何选择和设计最优化的输入滤波器。     

Robust performance analysis for uncertain negative‐imaginary systems

Negative‐imaginary systems are important in engineering practice as this class of systems appears quite often in practical problems, for example, lightly damped flexible structures with collocated position sensors and force actuators. In this paper, an analytical framework for robust performance of uncertain negative‐imaginary systems is proposed. The results are obtained by transforming negative‐imaginary systems into a bounded‐real framework via the positive‐real property. This paper deals with all the significant technical difficulties that appear due to the transformation and the punctured j ω‐axis frequency condition of negative‐imaginary systems. The problem is equivalently cast into a structured singular value condition that gives a quantitative performance test for this class of systems. This result also gives an analytical framework for robust stability when the perturbations are mixture of bounded‐real and negative‐imaginary uncertainties. A numerical example is presented to show the usefulness of the proposed methods. Copyright © 2011 John Wiley & Sons, Ltd.     

Dissipating energy flow method for locating the source of sustained oscillations

The modification of an energy-based approach called the dissipating energy flow (DEF) method is proposed, which uses data from phasor measurement units (PMUs) to trace the source of poorly damped natural and forced oscillations in power systems. The original energy-based approach (Chen et al., 2013) assumes the ability to determine steady-state values of variables measured by PMU during the transient process and that prevents the reliable use of the original method with actual PMU data. PMU data processing, proposed in the DEF method, is a key step in converting the energy-based method into a robust and automated tool for use with actual PMU data. The effectiveness of the proposed DEF method is demonstrated by testing multiple simulated cases of sustained oscillations, including both poorly damped natural and forced oscillations and more than 30 actual events in ISO New England (ISO-NE) and two events in Western Electricity Coordination Council (WECC) systems. The study also demonstrates the potential for using the DEF method to estimate the contribution of any generator to the damping of a specific oscillation mode.     

多轴重型越野车摆振的原因分析及其解决方法

通过对汽车前轮摆振相关影响因素的分析,及对多轴越野车摆振特性测试的研究,找到了转向系统阻尼小这一造成车辆摆振的影响因素.通过系统分析和样车试验的结果表明:在转向轮主销上换装阻尼止推轴承的方法能有效地解决多轴重型越野车前轮摆振的问题,从而提高多轴重型越野车高速行驶的操纵稳定性、舒适性和安全性.     

基于液—固耦合有限元仿真的液阻悬置集总参数模型动特性分析

探讨应用非线性固体有限元和液-固耦合非线性有限元仿真方法预测与识别液阻悬置集总参数模型的主要参数(如上液室的体积刚度和等效活塞面积、惯性通道中的液体和解耦板及其附连液体的惯性系数与流量阻尼系数等)的分析方法。在此基础上，利用集总参数分析模型对一种轿车用液阻悬置的动特性进行计算分析。数值预测结果与实测结果或近似解析计算结果的对比分析表明，基于液-固耦合有限元仿真方法的液阻悬置集总参数模型动特性分析技术是可行、有效的，其预测结果精度特性满足工程要求。应用这种方法，可以在液阻悬置的设计开发阶段较精确地预测产品的性能和进行优化设计，有利于提高产品设计质量、缩短开发周期。