Fault detection for continuous‐time switched systems under asynchronous switching

In this paper, the problem of fault detection for continuous‐time switched systems under asynchronous switching is investigated. The designed fault detection filter is assumed to be asynchronous with the original systems. Attention is focused on designing a fault detection filter such that the estimation error between the residual and the fault is minimized in the sense of H _∞ norm. By employing piecewise Lyapunov function and average dwell time techniques, a sufficient condition for the existence of such a filter is exploited in terms of certain linear matrix inequalities. Finally, an example of a switched electrical circuit is provided to illustrate the effectiveness of the proposed approach. Copyright © 2013 John Wiley & Sons, Ltd.     

基于Pro/TOOLKIT异步模式特征识别方法

对Pro／Engineer（Pro／E）二次开发工具Pro／TOOLKIT（PTC公司为Pro／E软件提供的二次开发工具包）的异步模式进行了研究，充分利用参数化技术，开发了实体模型的特征识别系统。系统可以控制Pro／E的自动启动及关闭，使其在后台运行。通过模型的调用实现实体特征的快速识别提取，为模具估价系统的智能化设计做好了准备。     

基于MATLAB/SIMULINK的异步电动机软起动控制系统的仿真

针对异步电动机直接起动会产生很大起动电流的特性,提出了一种基于PID控制原理的异步电动机软起动控制方法。利用MATLAB/SIMULINK对此闭环控制系统建立了仿真模型并进行了仿真实验。仿真结果表明采用PID控制的软起动控制方法可以有效地限制异步电动机的起动电流,因此该控制方法是正确有效的。     

基于覆盖技术的异步时序电路设计

该文根据动态卡诺图的原理,提出了异步时序电路设计的新方法-基于覆盖技术的异步时序电路设计法。该方法采用α,β覆盖,不仅可通过卡诺图直接得出整个电路的次态方程,而且与传统的异步时序电路设计方法相比,成本更低、功耗更低、延时更少。     

新的捷联惯性导航划桨误差补偿算法

针对实际捷联惯性导航系统解算中的圆锥误差和划桨误差,结合已解算出的当前时刻之前两个周期的姿态信息对旋转矢量进行修正的算法,利用算法的对偶性原理,将该算法应用于划桨误差补偿算法中。在划桨运动下对该算法进行了仿真,仿真结果表明,该划桨误差补偿算法具有与解析解相当的精度。     

一种单相异步电动机转速控制方法的研究与实现

针对单相电容启动式异步电动机调速中变频调速法不适用,而调压法不适于大范围调速的情况,提出了通过减少交流电源周期波以控制单相电容启动式异步电动机转速的方法.给出了单相异步电动机转速控制主电路及控制电路系统框图,介绍了以MSP430F413单片机系统为核心的转速控制系统硬件设计及程序设计实现方法.     

基于距离矢量路由协议的网络故障快速恢复方法

为了有效提高距离矢量路由协议处理网络故障的能力,提高网络的可用性,提出了一种基于 距离矢量路由协议的网络故障快速恢复机制,该机制包括基于预先计算生成的每目的多可行 下一跳的本地重路由策略和基于网络稳定性的触发更新策略. 分析和仿真结果显示,该机制可 以实现距离矢量路由网络的快速故障恢复,并能提高网络的稳定性和可用性.     

异步脑—机接口的空闲状态检测新方法*

提出一种新的空闲状态检测方法,以训练集中各类运动想象样本的类内散度和正确检测率为指标,结合接收机曲线确定分类阈值,设计最佳三分类器,并采用模糊化技术对预测标签进行处理。将该方法应用于2005年BCI竞赛数据IVc,测试的均方误差为0.278 7。实验结果验证了该方法的有效性。     

Asynchronous rotation scan for synthetic aperture interferometric radiometer

Synthetic aperture interferometric technique has wide applications in optics, radio astronomy and microwave remote sensing areas. With the increasing demands of high resolution imaging observation, a new time-sharing sampling scheme of asynchronous rotation scan is proposed to meet the technical challenge of achieving a large equivalent aperture and overcome the operating barriers of space borne application. This configuration is basically composed by two asynchronously and concentrically rotating antenna groups, whose revolving radii and speeds are different. The synthetic aperture system with asynchronous rotation scanning scheme can effectively solve the trade-off problem of system complexity, and greatly simplify the system hardware at the cost of sacrificing a certain time resolution. The basic rules and design methods of asynchronous rotation scan are investigated The Gridding method is introduced to inverse the spiral sampling data for image reconstruction. The potential applications of geostationary orbit (GEO) earth observation and solar polar orbit (SPO) plasma cloud observation are explored with numerical simulations to validate the significance and feasibility of this new imaging configuration. Supported by the National Natural Science Foundation of China (Grant No. 40574070, 40671121, 40701100 and 40801136) and the National High-Tech Research Program of China (“863” Program) (Grant No. 2006AA12Z141)     

基于Intel Xeon Phi的激光等离子体粒子模拟研究

激光等离子体粒子模拟广泛用于探索极端物质状态下的科学问题。将一种基于粒子云网格方法的三维等离子体粒子模拟程序LARED P移植到Intel Xeon Phi协处理器上。在移植的过程中,综合运用了Native和Offload两种编程模式：首先运用Native模式对LARED P程序中热点计算任务进行优化研究,通过采用SIMD扩展指令使该计算任务获得了4.61倍的加速;然后运用Offload模式将程序移植到CPU-Intel Xeon Phi异构系统上,并通过使用异步数据传输和双缓冲技术分别提升了程序性能9.8%和21.8%。