Marine air compressors work in a harsh environment, with multiple internal and external excitation sources. The collected noise signals are strongly time-varying, resulting in low fault diagnosis accuracy and thus difficulties in effective identification of various faults of marine air compressors. To address this problem, a fault diagnosis method combining Gramian Angular field (GAF) and Convolutional Neural Network (CNN) is proposed. Firstly, the basic principles, methods and implementation procedures of GAF and CNN are explained. Then, various faults of marine air compressors are simulated through experiments, and the noise signals of each fault are collected. The GAF is used to transform the one-dimensional time-domain signals into two-dimensional images, mapping the characteristic information to texture features such as colors and points of the two-dimensional images. Finally, the two-dimensional images are fed into CNN for feature extraction and fault diagnosis. The experimental results show that the proposed method can effectively identify various faults of the marine air compressor with a diagnostic accuracy of 99.2% superior to other algorithms, while ensuring the operational efficiency. It can provide technical references for the application of intelligent fault diagnosis systems for ships.

Marine scientific research uses marine scientific research equipment to obtain ocean data, collect and analyze it, and obtain ocean physical, chemical, biological and geological characteristics, which is an important way for humans to understand the ocean. The article combs the main scientific research history, current situation and changing characteristics at home and abroad since the formation of modern marine science, and discusses the goals, characteristics, results and impact of marine scientific research at different stages on the development of marine science. A summary is made regarding the current status of the development of marine scientific research equipment, focusing on describing the development history and current situation of domestic and foreign marine scientific research vessels, marine observation platforms and survey equipment; the development trends of marine scientific research are discussed and analyzed from the aspects of scientific research equipment, scientific research forms, scientific research characteristics, etc. The current challenges of domestic marine scientific research are put forward, and finally relevant suggestions are put forward for the high-quality development of marine scientific research.