飞行器内等速初始弯曲转子动力学特性的研究

研究了飞行器内等速运行的初始弯曲转子的动力学特性,分析了飞行器机动飞行对转子系统振动响应的影响．数值研究结果表明：飞行器俯仰角的变化使重力影响发生了变化,加上飞行器本身的机动飞行影响,转子的动力学特性与地面转子系统的特性有很大的不同．在飞行器加速初期,无论是在垂直方向单独加速或在水平、垂直两方向同时加速,转子振幅都会大幅上升,然后减小．在振幅减小的过程中会出现振幅先下降再上升的局部波谷现象．     

俄罗斯研制出新型水面舰舰载设备

据俄罗斯军事工业委员会2011年11月4日报道,俄罗斯克雷洛夫中央科学研究院研制出"КДС-703-01"新一代技术设备,是一种用于水面舰艇消磁的装备,可自动调节电流补偿回路。КДС-703-01设备采用了计算机领域最新     

Numerical analysis of nonlinear rotor-bearing-seal system

The system state trajectory, Poincard maps, largest Lyapunov exponents, frequency spectra and bifurcation diagrams were used to investigate the non-linear dynamic behaviors of a rotor-bearing-seal coupled system and to analyze the influence of the seal and bearing on the nonlinear characteristics of the rotor sys- tem. Various nonlinear phenomena in the rotor-bearing-seal system, such as periodic motion, double-periodic motion, multi-periodic motion and quasi-periodic motion were investigated. The results may contribute to a further understanding of the non-linear dynamics of the rotor-bearing-seal coupled system.     

非线性裂纹转子系统环面分叉的数值研究

通过对非线性裂纹转子系统的数值分析，发现Ｈｏｐｆ－Ｌａｎｄａｎ分叉是存在的，但分叉出的环面上的运行可能是周期的、拟周期的或混沌的，这反映出Ｈｏｐｆ－Ｌａｎｄａｎ分叉的存在与Ｎｅｗｈｏｕｓｅ－Ｒｕｅｌｌｅ－Ｔａｋｅｎｓ通向混沌的道路不相矛盾。     

On the algorithms of adaptive neural network-based speed control of switched reluctance machines

AbstractA switched reluctance machine(SRM)drive is a time-varying,strongly nonlinear system.High performance control can no longer be achieved by using linear techniques.This paper describes the back-propagation (BP)neural network-based proportional-integral-derivative(PID)speed control of the SRM.It’s the interest of this paper to explore the utilization of the prior empirical knowledge as guidance in the initializing and training of the neural networks.The purpose is to make the networks less sensitive on the initial weights.Two modified algorithms are presented and simulation experiments show some interesting findings about their control effects and their corresponding sensitivity on the initial weights of the networks.     

磁浮车不能稳定悬停在钢轨道框架上的原因分析

磁浮车辆不能稳定悬停在钢轨道框架上的原因,是由于钢轨道框架的自振频率与磁浮车的振动频率相近而引起的。用ANSYS软件分析了两种不同钢轨道框架的自振频率及模态。通过改变钢轨道框架立柱的侧向刚度,可以使结构的固有频率避开磁浮车的失稳频率敏感区。     

弹性车轮的发展与研究现状

介绍了弹性车轮的发展概况和国内外研究进展情况,其中包括弹性车轮的结构改进、降低轮轨噪声的理论和性能试验研究、寿命研究以及弹性车轮新材料研究进展情况,并在此基础上提出了今后的研究方向。     

俄罗斯初步通过新航母建造决议

俄罗斯新闻网2011年11月1日报道,据海军总司令部的消息称,俄罗斯海军司令部初步通过了2027年之前在太平洋和大西洋北部地区建设2个新航母打击群的决议。最终协议将由联邦总统签署。新航母的技术设计工作已经展开。初步数据表明,考虑到柴油动力会消耗大量燃料,故新航母将采用核动力。航     

电磁型磁悬浮列车动力学研究综述

在综合分析各国电磁型磁悬浮列车的发展现状和及其动力学研究的基础上，考虑车辆和轨道的相互作用，将悬浮列车和轨道作为一个整体，就电磁力、转向架、轨道变形和控制动力学稳定性分析等方面的问题，提出了今后研究的方向。     

The Modified Multiple Model Switching Tuning Control Application in AVC

In the complex mechanical vibration environment, the dominant frequency of the system varies remarkably and swiftly under various running conditions, which also characterizes uncertainty and time-variation. It is very impending and important to suppress or isolate the detrimental vibrations related to the above memtoned system with active vibration control (AVC) technology. This paper presented the improved linear quadratic gaussian (LQG) control scheme with a specified filter to realize broadband disturbance/noise attenuation and assure intensive suppression of vibration at the key vibration frequency, then applies and modifies the multiple model switching tuning (MMST) control method by disturbance observation to track the variation of dominant vibration component timely. The effectiveness and superiority of the presented control method were demonstrated by numerical simulation and AVC experiment on a flexible cantilever beam under sweeping excitation.