Intelligent Approaches for Anomaly Detection in Compressed Air Systems: A Systematic Review

Abstract

Inefficiencies within compressed air systems (CASs) call for the integration of Industry 4.0 technologies for financially viable and sustainable operations. A systematic literature review of intelligent approaches within CASs was carried out, in which the research methodology was based on the PRISMA guidelines. The search was carried out on 1 November 2022 within two databases: Scopus and Web of Science. The research methodology resulted in 37 papers eligible for a qualitative and bibliometric analysis based on a set of research questions. These aimed to identify specific characteristics of the selected publications. Thus, the review performed a comprehensive analysis on mathematical approaches, multiple machine learning (ML) methods, the implementation of neural networks (NNs), the development of time-series techniques, comparative analysis, and hybrid techniques. This systematic literature review allowed the comparison of these approaches, while widening the perspective on how such methods can be implemented within CASs for a more intelligent approach. Any limitations or challenges faced were mitigated through an unbiased procedure of involving multiple databases, search terms, and researchers. Therefore, this systematic review resulted in discussions and implications for the definition of future implementations of intelligent approaches that could result in sustainable CASs.

Low-cost Fault Diagnosis of Pneumatic Systems with Exergy and Machine Learning:

“…The exergy of compressed air is the maximum useful work that can be obtained from a certain amount of compressed air at a given state, with respect to a specified reference state. When neglecting the kinetic energy, potential energy, and chemical energy of ideal compressed air, the exergy could be calculated by (1) where ṁ is the mass flow rate of compressed air, c p is the specific heat capacity of air at constant pressure, and R ɡ is the gas constant of air, T and p are temperature and pressure of compressed air respectively, and T 0 and p 0 are the reference temperature and reference pressure respectively. In this study, the reference temperature is set as 25 ℃, and the reference pressure is set as 101325 Pa. For simplification, when neglecting the changes in temperature of compressed air in pneumatic systems, the exergy could be further simplified into the air power proposed by Cai et al 17) .…”