Intensive modal parameter identification method and device under underdetermined condition, equipment and medium

The invention provides a dense modal parameter identification method and device under an underdetermined condition, equipment and a medium, and relates to the technical field of working modal parameter identification, the method comprises the following steps: obtaining a linear time-invariant structure vibration response signal of a sensor measuring point, and constructing a third-order tensor according to the autocorrelation of vibration response signal data; a modal shape and a modal response matrix can be obtained after tensor decomposition; according to the method, the internal structure of data can be reflected more accurately, modal information can be effectively extracted and working modal parameters (modal shape, inherent frequency and the like) can be identified by integrating autocorrelation, PCA (Principal Component Analysis) and tensor decomposition even under the condition that sensors are limited (underdetermined), and the method can be used for monitoring large-scale structures. And further pos