Finding faults: A scoping study of fault diagnostics for Industrial Cyber-Physical Systems

TL;DR

This study reviews fault detection and diagnosis methods in Industrial Cyber-Physical Systems across aerospace, automotive, and industrial sectors, highlighting diverse techniques and real-world applications from 127 papers.

Contribution

It provides a comprehensive profile of current fault diagnosis approaches, comparing traditional and AI-based methods, and identifies gaps and trends in real-world applications.

Findings

Wide diversity of fault diagnosis techniques including Physics-based, AI, and Knowledge-Based methods.

Predictive diagnostics are prominent across sectors.

Hybrid approaches combining Model-Based and Data-Driven AI are common in real-world ICPS applications.

Abstract

Context: As Industrial Cyber-Physical Systems (ICPS) become more connected and widely-distributed, often operating in safety-critical environments, we require innovative approaches to detect and diagnose the faults that occur in them. Objective: We profile fault identification and diagnosis techniques employed in the aerospace, automotive, and industrial control domains. By examining both theoretical presentations as well as case studies from production environments, we present a profile of the current approaches being employed and identify gaps. Methodology: A scoping study was used to identify and compare fault detection and diagnosis methodologies that are presented in the current literature. Results: Fault identification and analysis studies from 127 papers published from 2004 to 2019 reveal a wide diversity of promising techniques, both emerging and in-use. These range from traditional Physics-based Models to Data-Driven Artificial Intelligence (AI) and Knowledge-Based approaches. Predictive diagnostics or prognostics featured prominently across all sectors, along with discussions of techniques including Fault trees, Petri nets and Markov approaches. We also profile some of the techniques that have reached the highest Technology Readiness Levels, showing how those methods are being applied in real-world environments beyond the laboratory. Conclusions: Our results suggest that the continuing wide use of both Model-Based and Data-Driven AI techniques across all domains, especially when they are used together in hybrid configuration, reflects the complexity of the current ICPS application space. While creating sufficiently-complete models is labor intensive, Model-free AI techniques were evidenced as a viable way of addressing aspects of this challenge, demonstrating the increasing sophistication of current machine learning systems.(Abridged)