摘要
提出了同步压缩小波时频脊提取结合自适应时域滤波的时变系统参数识别方法。同步压缩小波相比传统小波具有优异的时频分辨率,基于该小波时频脊提取可以获得时变结构的瞬时模态频率,在此基础上可构造各阶分量信号的载波矩阵,并应用自适应时域滤波求解分量信号的幅值包络,进而识别结构的阻尼比。该方法能对时变系统结构响应进行各阶分解,相比经验模态分解方法具有优异的时频提取能力、较强的抗噪性能和识别复杂时变问题的能力。在理论推导基础上,首先通过一个3自由度时变仿真算例验证了方法的正确性和抗噪性,再应用该算例构造了一个复杂时变算例(分量信号在频域重叠且突变),以此验证方法对各类复杂时变情况的适用性和准确性。
In this paper, an instantaneous modal parameter identification method for time-varying structures based on syn- chrosqueezed wavelet transform (SWT) and adaptive filtering is proposed. The time-frequency ridges of SWT are applied to the instantaneous frequency extraction of time-varying structures for their excellent time-frequency resolution. Then the carrier ma- trix of each order component signal can be constructed and the component signal amplitude envelope is calculated based on the a- daptive filter. On this basis, the structural damping ratio is identified. Compared with the empirical mode decomposition, this method has excellent time-frequency extraction capability, strong noise immunity and .strong applicability for various time-var-ying conditions. Based on the theory, the results of a three-degree-of-freedom time-varying simulation verify the correctness and anti-noise ability of the method. The example is also used to construct a complex time-varying situation in order to verify the applicability of the method, and the results show that this method can be applied to time-varying situations that component sig-nals overlap or even intersect in frequency domain.
作者
张杰
史治宇
ZHANG Jie;SHI Zhi-yu(State Key Laboratory of Mechanics and Control of Mechanical Structures,College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《振动工程学报》
EI
CSCD
北大核心
2019年第3期462-470,共9页
Journal of Vibration Engineering
基金
国家自然科学基金资助项目(11172131,11232007)
2015年度江苏省产学研前瞻联合研究项目(BY2015003-01)
机械结构力学及控制国家重点实验室(南京航空航天大学)自主研究课题(0515G01)
关键词
参数识别
同步压缩小波
时频脊提取
自适应滤波
时变系统
parameter identification
synchrosqueezed wavelet transform& time-frequency ridges extraction
adaptive filtering
time-varyingsystem
