基于TSEOPM的在轨航天器故障预报方法研究

针对在轨航天器非线性系统的故障预报,提出一种基于时间序列事件征兆模式挖掘的在轨航天器故障预报方法,该方法以在轨航天器遥测数据建立状态监测时间序列,根据事件特征函数利用层次聚类算法挖掘出故障事件征兆模式,然后利用故障事件征兆模式对航天器的状态监测时间序列数据进行分析,判断是否为故障征兆点,从而实现故障预报;实验结果表明,该方法能有效地预测在轨航天器状态监测时间序列数据中的故障事件。     

Output feedback control for uncertain linear systems with faulty actuators based on a switching method

This paper investigates the problem of output feedback stabilization for a class of uncertain linear systems with faulty actuators via the synergy with a switching strategy. When actuators suffer a ‘destabilizing failure’ and the never‐faulty actuators cannot stabilize the given system, the closed‐loop exponential stability can still be achieved via the average dwell‐time scheme employing an arbitrary switching signal. The prerequisite condition found requires the ratio between the two lapse times, when the system is devoid of faulty actuators and when it is not so, to be less than a certain specified constant. Then the stabilizing output feedback controls are designed via the technique of linear matrix inequalities. The illustrative example and the respective simulation results demonstrate the feasibility and effectiveness of the proposed design synthesis. Copyright © 2008 John Wiley & Sons, Ltd.     

Aligning Collaborative Business Processes—An Organization-Oriented Perspective

Business collaboration encompasses the coordination of information flows among organizations as well as the composition of their business processes toward mutual benefits. While integrating business processes of different organizations seamlessly, it brings great challenges to keep participating organizations as autonomous entities. To address this issue, we propose a new perspective on modeling collaborative business processes with a novel concept called relative workflow (RWF). With its visibility control mechanism, the RWF model defines what a participating organization can perceive in collaboration and thereby allows each organization to customize its own collaboration process and behaviors. In this paper, we present a formal definition of RWFs and related algorithms for generating RWFs. A prototype is implemented on the Web service platform for the proof-of-concept purpose.     

Tracking control for switched linear systems with time‐delay: a state‐dependent switching method

Tracking control for switched linear systems with time‐delay is investigated in this paper. Based on the state‐dependent switching method, sufficient conditions for the solvability of the tracking control problem are given. We use single Lyapunov function technique and a typical hysteresis switching law to design a tracking control law such that the H_∞ model reference tracking performance is satisfied. The controller design problem can be solved efficiently by using linear matrices inequalities. Since convex combination techniques are used to derive the delay independent criteria, some subsystems are allowed to be unstable. It is highly desirable that a non‐switched time‐delay system can not earn such property. Simulation example shows the feasibility and validity of the switching control law. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Impulsive controller design for singular networked control systems with packet dropouts

This paper considers the problem of impulsive time-delay control for singular networked impulsive control systems(SNICSs) and uncertain SNICSs both with network-induced delay and packet dropouts. The parameter uncertainty is assumed to be norm bounded. The problem to be addressed is the design of robust impulsive time-delay feedback controllers such that the exponential stability of the resulting closed-loop system is guaranteed for admissible uncertainties. By applying Lyapunov function theory and Halanay Lemma, impulsive time-delay controller is derived through solving LMIs. Numerical examples are provided to demonstrate the application of the proposed method.     

基于CPLD的ГOCT18977总线发送卡设计

针对某型俄制机载产品的测试需求,提出了一种ГOCT18977总线发送卡的设计方法介绍了ГOCT18977总线标准和80C196KB单片机、EPM7128LC可编程逻辑器件的使用方法,并利用外围电路和上述芯片设计并实现ГOCT18977总线发送卡,介绍了并口EPP模式下ГOCT18977总线数据的控制过程,给出了ГOCT18977总线发送卡的部分设计电路,并阐述了它的设计原理;实践验证了该板卡能够完成ГOCT18977总线数据信息格式转换和传输,完全可以满足对某型俄制机载产品性能检测的要求.     

基于CAN总线的模态测试悬挂控制系统设计

阐述了模态测试悬挂控制系统的研究意义,分析了模态测试悬挂控制系统的工作原理和硬件结构,制定了适合模态试验悬挂控制系统的CAN通讯协议,设计了底层电磁力与气压控制软件、上/下位机通信软件和上层工控机监控软件;试验结果表明,基于CAN总线的模态测试悬挂控制系统具有控制精度高、工作稳定可靠、通信速度快和可扩展性强等特点,很好地实现了模态测试悬挂控制系统预期的研制指标。     

特定三维人脸建模方法综述

介绍人脸建模的研究背景、研究内容以及研究热点,总结近期三维人脸建模的常用方法及优缺点,展望今后人脸建模的研究方向。三维建模是计算机视觉和计算机图形学领域中一个基本的问题,人脸因其普遍性和特殊性,成为众多研究人员的研究目标。     

基于P2P技术的分布式PKI证书撤销列表发布

大规模PKI（Public Key Infrastructure）的核心在于数字证书的发放和管理,目前,PKI的管理机构一般采用证书撤消列表（Certificate Revocation List,简称CRL）的方式管理失效证书,但这些发布机制都不能有效地减低服务器端证书存储库的负荷。因此,在P2P技术的基础上,提出了一种分布式的CRL发布机制,该策略不仅在服务器端降低了峰值请求率,而且发挥了P2P网络中资源的版本越多越有利于资源的发现和共享的优点。