A NOVEL METHOD FOR IDENTIFYING SYSTEM MODAL PARAMETERS USING STABILIZATION DIAGRAM

Wen-sheng Xiao¹, Zhong-yan Liu¹, Jian Liu¹, Han-chuan Wu²

¹College of Machinery and Electronic Engineering, China University of Petroleum, Qingdao, Shandong, China, 266555

²SJ Petroleum Machinery Co., Jingzhou, Hubei, China, 434024

Modal parameters of a structure are important for system identification. In order to identify modal parameters of a structure more accurately, this paper proposes a parameter identification method combined with stabilization diagram. Stochastic subspace identification (SSI) is a recently developed method for identifying a linear system. Combining SSI and the proposed method can easily confirm system order. However, the proposed method has difficulty in distinguishing spurious modals. Therefore, the proposed method must be revised to ensure that the spurious modal can be detected and the SSI can be used to improve identification accuracy. Finally, a simulation is conducted on a fracturing pump truck, when the damping ratio increases from 10% to 40%, those spurious modals disappear. The results indicate that this method performs precise identification.