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Research on the method of fault detection for ACM based on singular value decomposition

In order to solve the problem of environmental noise interference in the detection process of Air Cycle Machine of civil aviation aircraft due to the strong randomness for environmental noise, a method of singular value decomposition filtering is adopted in this paper. The acquired characteristic temperature signal of the Air Cycle Machine is used to construct a Hankel matrix, and the matrix is decomposed through singular value decomposition (SVD). The filtering threshold of the singular value was calculated according to the signal-to-noise ratio (SNR) of the sample, and when the SNR is high, the threshold is calculated based only on the SNR, when the SNR is low, the variance of the noise and the dimension of the matrix are used to estimate the threshold. The effective signal is restored by reconstructing the matrix, and the fault state could be judged by the T-test in statistics. The results of simulation experiments show that the detection method of singular value decomposition filtering is suitable for detecting aircraft ACM and the result is accurate.