A Wavelet and State Space-based Approach for Instantaneous Frequency Identification of Linear Time-Varying System

摘要：

This paper describes the method to identify the instantaneous frequency of the linear time-varying system based on wavelet and state space methods by using free vibration response data or forced vibration response data. Firstly, the second-order vibration differential equations are rewritten as first-order differential equations using state space method. Secondly, both excitation and response signals are projected by the Daubechies wavelet scaling functions, thus the state equations are transformed into simple linear equations using the orthogonality of the scaling functions. Lastly, the time-varying equivalent state space system matrices of LTV system are identified directly by solving the linear equations. The instantaneous frequencies are determined via eigenvalue decomposition of the state space system matrices. The proposed algorithm is investigated with a four degrees-of-freedom spring-mass-damping model. Numerical results demonstrate that the proposed method is robust and effective for identification of the abruptly, smoothly and periodically time-varying frequencies.

关键词： time-varying state space wavelet identification

作者: Xin Xu Zhiyu Shi Wenyun Wang Shuangli Long

作者单位: College of Aerospace and Engineering Nanjing University of Aeronautics & Astronautics Nanjing, China

会议类型: 国际会议

会议名称: 2010 International Conference on Measurement and Control Engineering(2010年IEEE测量与控制工程国际会议 ICMCE2010)

会议地点: 成都

会议语种:英文

页码: 70-74

在线出版日期: 2010-11-16（万方平台首次上网日期，不代表论文的发表时间）