Mechanical vibration signal compression by LOT-based subband coding

A novel compression method for the mechanical vibration signals is proposed in this paper. The vibration signal is first decomposed into subbands, by the intermediate of the Lapped Orthogonal Transform. Next, adaptive bit allocation is done on per subband basis and uniform quantization is performed in each subband. The method is applied on a large number of mechanical vibration signals issued by aircraft engines and it shows good results. Due to the quality of the decoding, the reconstructed signals are usable by post-compression treatments, such as fault detection for health monitoring purposes.