Nagabhushan Mahadevan, Abhishek Dubey, Gabor Karsai, Anurag Srivastava, Chen-Ching Liu
Annual Conference of the Prognostics and Health Management Society 2014
Effective fault diagnosis in cyber-physical systems requires understanding both physical and cyber failure mechanisms. This work is innovative because it provides formal mathematical foundations for temporal causal diagrams integrating physical and logical system aspects. The extended diagnosis approach improves accuracy by accounting for system-level effects and temporal constraints.
This work presents a framework for formal analysis of Temporal Causal Diagrams applied to cyber-physical system fault diagnosis. The methodology extends TFPG models with behavioral semantics enabling system-level reasoning about failure modes and their effects. The approach includes improved diagnosis algorithms that account for internal mode changes and timing delays in protection systems.
The formal framework successfully models power system failures and enables hypothesis generation for fault diagnosis. Improved reasoning algorithms identify failure modes with consideration of system timing constraints and state dependencies. Results demonstrate enhanced diagnostic accuracy for complex multi-component failures.
@inproceedings{Mahadevan2014,
author = {Mahadevan, Nagabhushan and Dubey, Abhishek and Karsai, Gabor and Srivastava, Anurag and Liu, Chen-Ching},
booktitle = {Annual Conference of the Prognostics and Health Management Society},
title = {Temporal Causal Diagrams for diagnosing failures in cyber-physical systems},
year = {2014},
month = {jan},
abstract = {Resilient and reliable operation of cyber physical systems of societal importance such as Smart Electric Grids is one of the top national priorities. Due to their critical nature, these systems are equipped with fast-acting, local protection mechanisms. However, commonly misguided protection actions together with system dynamics can lead to un-intentional cascading effects. This paper describes the ongoing work using Temporal Causal Diagrams (TCD), a refinement of the Timed Failure Propagation Graphs (TFPG), to diagnose problems associated with the power transmission lines protected by a combination of relays and breakers. The TCD models represent the faults and their propagation as TFPG, the nominal and faulty behavior of components (including local, discrete controllers and protection devices) as Timed Discrete Event Systems (TDES), and capture the cumulative and cascading effects of these interactions. The TCD diagnosis engine includes an extended TFPG-like reasoner which in addition to observing the alarms and mode changes (as the TFPG), monitors the event traces (that correspond to the behavioral aspects of the model) to generate hypotheses that consistently explain all the observations. In this paper, we show the results of applying the TCD to a segment of a power transmission system that is protected by distance relays and breakers.},
category = {conference},
contribution = {colab},
file = {:Mahadevan2014-Temporal_Causal_Diagrams_for_Diagnosing_Failures_in_Cyber_Physical_Systems.pdf:PDF},
keywords = {temporal causal diagrams, fault diagnosis, cyber-physical systems, timed discrete event systems, formal analysis},
tag = {platform,power},
month_numeric = {1}
}