Leakage is the most important failure mode in aircraft hydraulic systems caused by wear and tear between friction pairs of components. The accurate detection of abrasive debris can reveal the wear condition and predict a system’s lifespan. The radial magnetic field (RMF)-based debris detection method provides an online solution for monitoring the wear condition intuitively, which potentially enables a more accurate diagnosis and prognosis on the aviation hydraulic system’s ongoing failures. To address the serious mixing of pipe abrasive debris, this paper focuses on the superimposed abrasive debris separation of an RMF abrasive sensor based on the degenerate unmixing estimation technique. Through accurately separating and calculating the morphology and amount of the abrasive debris, the RMF-based abrasive sensor can provide the system with wear trend and sizes estimation of the wear particles. A well-designed experiment was conducted and the result shows that the proposed method can effectively separate the mixed debris and give an accurate count of the debris based on RMF abrasive sensor detection.

Cyber–physical systems (CPSs) facilitate the integration of physical entities and cyber infrastructures through the utilization of pervasive computational resources and communication units, leading to improved efficiency, automation, and practical viability in both academia and industry. Due to its openness and distributed characteristics, a critical issue prevalent in CPSs is to guarantee resilience in the presence of node injection attack. This survey provides a detailed and comprehensive overview of recent advances on resilient coordination against node injection attacks for CPSs based on the idea of mean subsequence reduction (MSR). Different from existing survey papers that adopt a horizontal taxonomy based on attack type, we propose a vertical taxonomy according to the multilayered framework of CPS, which enables a more in-depth of the latest developments in MSR-based resilient coordination results. Furthermore, the proposed taxonomy fills the gap that no survey has gathered and classified numerous MSR-type papers from the perspective of system structure. Specifically, more than 100 MSR-based resilient coordination results are classified and reviewed from three perspectives: physical structure, network topology, and communication mechanism. Finally, three typical application scenarios, i.e., resilient frequency synchronization for single-phase microgrids, resilient containment for multirobot systems (MRSs), and resilient distributed optimization for multimicrogrid systems, are examined, all of which demonstrate the applicability of the reviewed MSR-based strategies.