Optimization and assessment of blade tip timing probe layout with concrete autoencoder and reconstruction error

Abstract

Blade tip timing (BTT) is a promising non-contact measurement method for blade vibration monitoring. The limited number of probes leads to the inherent under-sampled problem of BTT signal. The quality of the analysis result of under-sampled signal depends on the probe layout. However, the application of existing probe layout optimization methods requires domain knowledge about blade vibration. Additionally, the lack of comparisons of probe layouts generated by different probe layout optimization methods makes it difficult to evaluate the performance of different methods. In this paper, we proposed a new probe layout optimization method based on a concrete autoencoder to reduce the reliance on the domain knowledge. The probe layouts were compared using an independently trained reconstructor in the time domain. And the spectral distance was defined to evaluate the performance of different probe layouts in the frequency domain. The validation results showed that the proposed method has superior time domain reconstruction performance and decent frequency domain reconstruction performance compared to other methods. The most informative and representative probe layout can be effectively selected by the proposed method.