Preliminary reliability analysis of autonomous underwater vehicle in the polar environment based on failure mode and effects analysis and fault tree analysis

Abstract

Autonomous underwater vehicles (AUVs) are often used in extreme environments, making reliability assessment important. To evaluate the preliminary reliability of AUVs operating in polar environments, this study utilized failure mode and effects analysis (FMEA) and fault tree analysis (FTA). FMEA was conducted based on the functional analysis of the AUV, identifying nineteen potential failure modes and thirty failure causes. The results suggest correlations between major failures, accidents, and their causes. Using the FMEA results, a fault tree diagram was constructed by defining the loss of the AUV as the top event (TE) causing the greatest loss. The study categorized basic events (BEs) into two categories: BEs related to equipment reliability, such as equipment aging, equipment failure, and manufacturing defects, and BEs caused by polar environmental factors, such as collision with ice, low-temperature environment, and thermocline. By conducting a literature review, it was obtained failure probabilities of BEs. Using the obtained information, preliminary reliability analysis was conducted. This research can be useful for designing and testing AUVs that can perform reliably in extreme environments.