阵列导波检测数据分段式混合压缩算法研究

针对阵列导波检测中形成的大量数据对后续传输与存储所构成的挑战，本文提出了一种分段式混合压缩算法。基于损伤散射信号的高幅值及相关性特征，将检测数据划分为高、低保真段两部分。在高保真段设计了LOPCM无损压缩方法，在低保真段则应用JPEG有损压缩算法，以此兼顾压缩比与损伤信号的保真度。构建实验平台获取实测信号并实施压缩：对比验证了LOPCM方法的有效性；考察信号整体的误差指标，并结合重构数据成像结果，评估了分段式混合压缩算法对成像精度的影响。结果表明，该算法能够在保证损伤成像精度的基础上有效减少数据量，相较于仅采用无损或有损压缩能更好地满足阵列导波检测中对数据压缩的需求。

Segmental Hybrid Compression Algorithm of Array Guided Wave Detection Data

Aiming at the challenge to subsequent transmission and storage caused by large amount of data in array guided wave detection, a segmental hybrid compression algorithm is proposed in this paper. Based on the high amplitude and correlation characteristics of damage scattering signal, the detection data is divided into high and low fidelity segments. To consider both compression ratio and the fidelity of damaged signal, LOPCM lossless compression method is designed for the high-fidelity segment, and JPEG lossy compression algorithm is applied for the low fidelity segment. After constructing experimental platform, the measured signals are obtained and compressed. The effectiveness of LOPCM method was verified by comparison. The influence of the piecewise hybrid compression algorithm on the imaging accuracy is evaluated by investigating the overall error index of the signal and combining with the reconstructed data imaging results. The results show that the proposed algorithm can effectively reduce the amount of data while ensuring the accuracy of damage imaging, and it can better meet the requirements of data compression in array guided wave detection than only using lossless or lossy compression.