Inductive Wear-Debris Monitoring in Lubricated Systems: Recent Advances, Challenges, and Prospects

Abstract Excessive wear of mechanical components is a major cause of performance degradation and failure in lubricated machinery. wear-debris suspended in lubricating oil carries direct information on friction and wear processes, and its online detection is therefore important for early warning of abnormal wear and wear diagnosis. Among available approaches, inductive wear-debris monitoring has attracted sustained interest because of its simple structure, nonintrusive implementation, and relatively low sensitivity to oil quality. This paper reviews recent advances in inductive wear-debris monitoring in lubricated systems. Representative sensing principles, sensor configurations, detection capabilities, induced-voltage models, and signal-processing methods are summarized and compared. Emphasis is placed on the detection of ferromagnetic and non-ferromagnetic debris, the interpretation of debris-induced voltage responses, and the challenges associated with weak-signal extraction and quantitative characterization. Furthermore, it examines unresolved key issues in this field and explores potential solutions, including interference resistance, detection consistency under variable operating conditions, establishing reliable mapping relationships between sensor outputs and debris morphology, as well as standardized benchmark testing and health-oriented deployment frameworks. This review is intended to provide a concise reference for the development of inductive oil-debris monitoring techniques and their application in tribological condition assessment of lubricated machinery.