A Reliability Analysis Method of Electro‐Hydrostatic Actuator Based on MDD‐GO‐FLOW Methodology

As a key actuation unit in aviation, the reliability of the Electro‐Hydrostatic Actuator (EHA) is directly related to aircraft operational safety, making a reliable assessment essential. The Goal Oriented‐FLOW (GO‐FLOW) method is widely used for dynamic reliability analysis of EHAs; however, when shared signals and multi‐state components are present, it can suffer from state‐combination explosion, and probability expressions often require repeated correction, reducing both efficiency and accuracy. To overcome these limitations, this paper proposes an integrated reliability analysis approach that combines GO‐FLOW with multi‐valued decision diagrams (MDDs). Mapping rules between GO‐FLOW operators and MDD nodes are established to convert the EHA GO‐FLOW model into a structured MDD representation that compactly characterizes system topology. A multi‐valued function is then formulated to relate component state combinations to the system operating state. Exploiting the path‐search property of MDDs, a fast procedure is developed to derive minimum path sets and minimum cut sets. Finally, probability evaluation is performed via a recursive algorithm based on Shannon decomposition, yielding the occurrence probabilities of the multi‐valued function and the probability distribution over EHA operating states. Comparative studies against the conventional GO‐FLOW methodology demonstrate that the proposed framework delivers consistent results while substantially reducing computational burden and alleviating the explosion problem. The method provides an efficient tool for reliability assessment of aviation critical components with multi‐state behavior and multi‐signal coupling.