Method and device for extracting characteristic quantity of unbalanced vibration signal

The invention provides a method and a device for extracting characteristic quantity of an unbalanced vibration signal. The method comprises the following steps of: simultaneously acquiring the unbalanced vibration signal and a rotating speed pulse signal of a main shaft; performing modal decomposition on the unbalanced vibration signal, determining the number of modal components according to an energy loss coefficient, and obtaining a plurality of modal components of the unbalanced vibration signal; determining rotation frequency according to the rotation speed pulse signal, constructing a reference vibration signal according to the rotation frequency, calculating correlation coefficients of a plurality of modal components and the reference vibration signal, and obtaining the modal component with the maximum correlation coefficient; and obtaining a characteristic quantity according to the modal component with the maximum correlation coefficient. The method provided by the invention can accurately extract the