Optimal Management of Analytical Redundancy in Reconfigurable Control Systems

提出的研究是关于通过管理分析冗余来开发新的方法来增强可重构控制系统的容错性。冗余管理涉及到在确定某些故障后，是否以及如何进行控制重新配置以维持一定的系统性能水平的决策。由于系统和外生信号模型中存在不确定性，在进行故障检测和识别（FDI）时处理/记忆能力有限，以及在控制性能的背景下故障定义的模糊性，使得这样的决策变得困难。研究的潜在问题范围从在子系统级别定义的问题到在整个系统级别制定的问题。在整个系统的层面上，我们的任务包括找到一种客观评估可靠性的方法，考虑到失败的重新配置操作的可能性。因此，有必要定义和计算重构覆盖率。提出了覆盖率的定义，该定义采用与估计的减值参数相关的两个非特异性度量的比率的形式。它明确地将重构覆盖范围与可用的FDI解决方案、选择的控制性能阈值、选择的控制设置和使用的排名方法联系起来。因此，它提供了一种方法，通过数值和解析的手段，探索各个子系统模块的性能与整个系统的可靠性之间的关系。在重新配置决策的层面上，我们的任务包括形成策略，通过优化管理系统中的分析冗余来实现最高可能的重新配置覆盖率。提出决策相当于对两类模糊集之间的关系进行排序。一类表示对每个控制设置评估的控制性能，另一类表示通过FDI方案生成的估计减值参数。为了开发实现这些策略的算法，有必要表明这些表示是可获得和可实现的。还需要搜索能够最大化覆盖范围且易于执行的排名方法。在子系统模块的层次上，我们的任务包括导出所需的FDI分辨率。利用已识别的减值参数的非特异性度量，提出了FDI解决的定义，揭示了控制子系统模块与FDI子系统模块之间在分析冗余管理方面的一些相互作用。本研究将对这些关系进行进一步的研究和量化，为底层设计，即控制子系统和FDI子系统模块的设计提供更精细的指导。到目前为止产生的结果适用于回顾性或新的控制/外国直接投资设计。在高度综合考虑的标准下，新的设计可以从这一点开始冒险。一个类似于F-16的飞机模型，受到致动器/表面损伤，将用于底层设计，也用于通过仿真和分析验证提出的新概念。

ECS-9615956 Wu The proposed research is concerned with developing new approaches to enhancing fault tolerance of reconfigurable control systems through management of analytical redundancy. The redundancy management involves a decision, upon the identification of some failures, on whether and how a control reconfiguration should take place in order to maintain a certain system performance level. Such a decision is made difficult by the presence of uncertainties in the system and the exogenous signal models, by the limited processing/memory capability in carrying out failure detection and identification (FDI), and by the vagueness in the definition of a failure in the context of control performance. The underlying issues of the research range from those defined at subsystems level to those formulated at the overall systems level. At the level of overall systems, our task involves finding a way of assessing objectively the reliability that takes into account the likelihood of failed reconfiguration action. Therefore, there is a need to define and compute the reconfiguration coverage. A definition for coverage is proposed that takes the form of a ratio of two nonspecificity measures associated with the estimated impairment parameter. It links explicitly the reconfiguration coverage to the available FDI resolution, the chosen control performance threshold, the selected control settings, and the ranking method used. Therefore, it offers a way to explore, through numerical and analytical means, the relationship between the performance of individual subsystem modules and the reliability of the overall system. At the level of reconfiguration decisions, our task involves forming strategies for achieving the highest possible reconfiguration coverage by optimally managing the analytical redundancy in the system. It is proposed that the decision making amount to ranking the relationships between two classes of fuzzy sets. One class represents the control performance evaluated for every control setting, and the other represents the estimated impairment parameter generated through an FDI scheme. In order to develop algorithms that implement the strategies, it is necessary to show that these representations are obtainable and realizable. It is also necessary to carry out a search for a ranking method that maximizes the coverage, and is simple to execute. At the level of subsystem modules, our task involves deriving the required FDI resolution. A definition of FDI resolution is proposed using the nonspecificity measure of the identified impairment parameter, which has uncovered some interactions between the control subsystem module and the FDI subsystem module, in relation to analytical redundancy management. These relationships are to be further studied and quantified in this research to provide a more refined guideline for the bottom level design, i.e., the design of control and FDI subsystem modules. Results to be produced thus far are applicable to control/FDI designs that are either retrospective or new. New designs under the criteria of highly integrated consideration can be ventured from this point on. An F-16 like aircraft model subject to actuator/surface impairment is to be used for the bottom level design, and also for the verification of the proposed new concepts through simulation and analysis.