微机监测设备故障容错控制及其应用研究

故障诊断与控制理论相结合用于设备的故障控制．是故障诊断领域里一个很有前途的研究课题，本文根据工业设备的故障特点，提出利用容错技术对设备故障进行控制的设计方法．重点介绍故障容错控制系统的基本结构及其实现方法，文末给出了一个工程应用实例．     

Reliable regulation in centralized control systems

This paper addresses the design of a reliable control system for a linear, asymptotically stable plant. Specifically, the considered problem consists in finding a regulator which guarantees asymptotic stability, signal tracking and disturbance rejection when all the instrumentation is operational, and ensures that these properties are preserved, to the maximum possible extent, when an arbitrary number of sensors and/or actuators faults occur, that is, some of the feedback loops open. With reference to a centralized control structure and exogenous signals with multiple poles on the imaginary axis, the paper supplies a necessary and sufficient condition for the problem to admit a solution, and a possible least order regulator.     

Pancyclicity of ternary n-cube networks under the conditional fault model

A graph G is said to be conditional k-edge-fault pancyclic if after removing k faulty edges from G, under the assumption that each vertex is incident to at least two fault-free edges, the resulting graph contains a cycle of every length from its girth to |V(G)|. In this paper, we consider ternary n-cube networks and show that they are conditional (4n−5)-edge-fault pancyclic.     

Fault-tolerant decentralized H-infinity control for multi-channel systems using homotopy method

This paper considers a fault-tolerant decentralized H-infinity control problem for multi-channel linear time-invariant systems. The purpose is to design a decentralized H-infinity output feedback controller to.stabilize the given system and achieve a certain H-infinity performance requirement both in the normal situation and in the situation where any one of the local controllers fails. The designed problem is reduced to a feasibility problem of a set of bilinear matrix inequalities （BMIs）. An algorithm is proposed to solve the BMIs. First, the normal situation is considered where all the local controllers are functioning. The local controllers are obtained from a standard centralized H-infinity controller by using a homotopy method imposing a structural constraint progressively. Secondly, the above case is extended to the one where any one of the local controllers fails. We again use a homotopy method where the coefficient matrices of the failed controller are decreased progressively to zero. The efficiency of the proposed algorithm is demonstrated by an example.     

Interval observer framework for fault-tolerant control of linear parameter-varying systems

This paper addresses the problem of passive fault-tolerant control for linear parameter-varying systems subject to actuator faults. The FTC, based on a linear state feedback, is designed to compensate the impact of actuator faults on system performance by stabilising the closed-loop system using interval observers. The design of interval observers is based on the discrete-time Luenberger observer structure, where uncertainties and faults with known bounds are considered. Sufficient conditions for the existence of the proposed observer are explicitly provided. Simulation results are presented to show the effectiveness of the proposed approach.     

Safe diagnosability for fault-tolerant supervision of discrete-event systems

The problem of achieving fault-tolerant supervision of discrete-event systems is considered from the viewpoint of safe and timely diagnosis of unobservable faults. To this end, the new property of safe diagnosability is introduced and studied. Standard definitions of diagnosability of discrete-event systems deal with the problem of detecting the occurrence of unobservable fault events using model-based inferencing from observed sequences of events. In safe diagnosability, it is required in addition that fault detection occur prior to the execution of a given set of forbidden strings in the failed mode of operation of the system. For instance, this constraint could be required to prevent local faults from developing into failures that could cause safety hazards. If the system is safe diagnosable, reconfiguration actions could be forced upon the detection of faults prior to the execution of unsafe behaviour, thus achieving the objective of fault-tolerant supervision. Necessary and sufficient conditions for safe diagnosability are derived. In addition, the problem of explicitly considering safe diagnosability in controller design, termed “active safe diagnosis problem”, is formulated and solved. A brief discussion of safe diagnosability for timed models of discrete-event systems is also provided.     

基于Interceptor的容错ORB原型系统

介绍了基于Interceptor机制的容错ORB原型系统的体系结构和运行机制,说明了该容错CORBA系统设计中的一些重要问题和解决方案。对该系统的测试表明它能提供基本的容错功能。     

实时协同编辑系统的容错流量控制研究

为了有效利用网络带宽、降低网络流量,并在保持逻辑向量时钟的检查点全局一致基础上,使得系统在恢复复制进程时,做到网络流量小、等待时间短、用户费用少,容错系统将依据编辑文档的编辑距离、编辑相似度,以最小的代价为恢复进程提供最新检查点和最新文档,实现广域网环境下优化的实时协同编辑系统。提出流量控制的算法,并通过OPNET建模和实验测试,对整个系统容错时的流量进行了分析。     

Multivariable adaptive control: A survey

Adaptive control is a control methodology capable of dealing with uncertain systems to ensure desired control performance. This paper provides an overview of some fundamental theoretical aspects and technical issues of multivariable adaptive control, and a thorough presentation of various adaptive control schemes for multi-input–multi-output systems, literature reviews on adaptive control foundations and multivariable adaptive control methods, and related technical problems. It covers some basic concepts and issues such as certainty equivalence, stability, tracking, robustness, and parameter convergence. It discusses some of the most important topics of adaptive control: plant uncertainty parametrization, stable controller adaptation, and design conditions for different adaptive control schemes. The paper also presents a detailed study of well-developed multivariable model reference adaptive control theory and design techniques. It provides an introduction to multivariable adaptive pole placement and adaptive nonlinear control, and it concludes by identifying some open research problems.     

基于DBNs理论的多传感器信息融合方法

为了提高多传感器信息融合系统的动态优化和容错能力,应用动态贝叶斯网络理论对传统联邦滤波器进行改造,得到了一种可以实现高动态环境条件下多传感器信息主动动态优化配置的信息融合方法．仿真结果表明,这种信息融合方法具有较强的动态适应和容错能力．