A Uniform Framework for Diagnosis of Discrete-Event Systems With Unreliable Sensors Using Linear Temporal Logic

• Published in: IEEE transactions on automatic control Vol. 69; no. 1; pp. 145 - 160
• Main Authors: Dong, Weijie, Yin, Xiang, Li, Shaoyuan
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Diagnosability; Discrete event systems; Failure; Fault diagnosis; Intelligent sensors; linear temporal logic; Semantics; sensor failure; Sensor systems; Sensors; Temporal logic
• ISSN: 0018-9286; 1558-2523
• DOI: 10.1109/TAC.2023.3266021

In this article, we investigate the diagnosability verification problem of partially-observed discrete-event systems (DES) subject to unreliable sensors. In this setting, upon the occurrence of each event, the sensor reading may be nondeterministic due to measurement noises or possible sensor failures. Existing works on this topic mainly consider specific types of unreliable sensors such as the cases of intermittent sensors failures, permanent sensor failures or their combinations. In this work, we propose a novel uniform framework for diagnosability of DES subject to, not only sensor failures, but also a very general class of unreliable sensors. Our approach is to use linear temporal logic (LTL) with semantics on infinite traces to describe the possible behaviors of the sensors. A new notion of <inline-formula><tex-math notation="LaTeX">\varphi</tex-math></inline-formula>-diagnosability is proposed as the necessary and sufficient condition for the existence of a diagnoser, when the behaviors of sensors satisfy the LTL formula <inline-formula><tex-math notation="LaTeX">\varphi</tex-math></inline-formula>. An effective approach is provided to verify this notion. We show that, our new notion of <inline-formula><tex-math notation="LaTeX">\varphi</tex-math></inline-formula>-diagnosability subsumes all existing notions of robust diagnosability of DES subject to sensor failures. Furthermore, the proposed framework is user-friendly and flexible since it supports an arbitrary user-defined unreliable sensor type based on the specific scenario of the application. As examples, we provide two new notions of diagnosability, which have never been investigated in the literature, using our uniform framework.