Failure Diagnosis of Modular and Decentralized Discrete Event Systems

对复杂技术系统的性能和可靠性的要求越来越严格，有必要开发系统的方法，以及时准确地诊断系统故障。 几年来，我们一直在开发一种方法，集中故障诊断使用离散事件系统（DES）的方法。 这种方法已成功地应用于industry.We建议建立在我们以前的集中式和分散式故障诊断DES的结果，以开发一个全面的方法，故障诊断的大型复杂系统的模块化和分布式架构，间歇性故障可能发生。 我们的主要重点是系统的在线诊断，即，而不是在系统不工作时对系统进行离线测试。 我们的研究将包括：（P1）在集中式架构的背景下诊断间歇性故障;（P2）在协调分散式架构的背景下处理通信延迟;（P3）开发分散式故障诊断的新技术，在不同站点的本地诊断模块之间进行通信;以及（P4）开发利用故障诊断中系统结构的模块化的新技术。 这些问题是基于我们的方法的工业应用中收到的反馈，旨在扩大其适用性。 问题（P1）和（P2）将直接基于我们先前在集中式和协调式分散式故障诊断架构上的工作。 问题（P3）和（P4）旨在将我们的方法论的范围扩展到新的方向。 在问题（P3）中，我们打算利用站点之间的通信来增强具有分散信息的系统的诊断能力。 在问题（P4）中，我们打算利用系统结构来实现模块化系统故障诊断中的计算节省，从我们对上述问题的通用形式化方法中获得的见解将为设计ad hoc诊断协议提供指导，这些协议将具有降低的复杂性并且仍然具有良好的性能。 因此，在这个建议中描述的研究将有重大影响的系统设计的故障诊断协议的各种复杂的工程和计算系统。

The increasingly stringent requirements on performance and reliability of complex technological systems have necessitated the development of systematic methods for timely and accurate diagnosis of system faults. For several years, we have been developing a methodology for centralized failure diagnosis using a discrete event systems (DES) approach. This methodology has been successfully applied in industry.We propose to build on our previous results on centralized and decentralized failure diagnosis of DES in order to develop a comprehensive methodology for failure diagnosis of large-scale complex systems with modular and distributed architectures where intermittent failures may occur. Our primary focus is the on-line diagnosis of the system, i.e., while it is operating, as opposed to off-line testing of a system when it is not under operation. Our research will include:(Pl) diagnosis of intermittent failures in the context of centralized architectures;(P2) dealing with communication delays in the context of coordinated decentralized architectures;(P3) development of new techniques for decentralized failure diagnosis with communication among local diagnostic modules at different sites; and (P4) development of new techniques exploiting the modularity of the system structure in failure diagnosis. These problems are based on feedback received from industrial applications of our methodology and aim at extending its applicability. Problems (PI) and (P2) will be directly based on our prior work on centralized and coordinated decentralized architectures for failure diagnosis. Problems (P3) and (P4) aim at extending the scope of our methodology in new directions. In Problem (P3) we intend to exploit communication among sites to enhance diagnostic capabilities in systems with decentralized information. In Problem (P4) we intend to exploit system structure to achieve computational savings in failure diagnosis of modular systems.The insight gained from our generic formal approach to the above-mentioned problems will provide the guidelines for the design of ad hoc diagnostic protocols that will have reduced complexity and still perform well. Therefore the research described in this proposal will have a significant impact on the systematic design of failure diagnosis protocols for a wide variety of complex engineering and computing systems.