The application relates to a bridge
modal parameter automatic identification method and
system considering multi-channel information, which comprises the following steps: S1, generating a
stability diagram by directly analyzing multi-channel monitoring signals by using COV-SSI, automatically extracting stable axes by combining a
DBSCAN clustering
algorithm, and realizing automatic identification of
modal frequencies; S2, decomposing multi-channel
monitoring data by using MvFIF to generate an intrinsic
modal function (IMF) group with modal alignment characteristics; S3, calculating the instantaneous frequency and bandwidth of the IMF in step S2 by using HHT, screening out an IMF component containing a target modal frequency, and performing
linear reconstruction; and S4, taking the multi-channel
monitoring data after the reconstruction in step S3 as
system input of the COV-SSI
algorithm, calculating a
system matrix and an output matrix, and calculating modal damping ratios by using eigenvalue
decomposition; the method can consider the space-
time correlation between multi-
channel data, realize synchronous
decomposition of multi-channel
monitoring data, and realize automatic and accurate identification of structural modal parameters under different
noise levels.