Synchronization between excitation and response signals in frequency response function estimation for mimo random vibration test
CUI Xu-li, CHEN Huai-hai, HE Xu-dong, JIANG Shuang-yan
MOE Key Lab of Structure Mechanics and Control for Aircraft; Institute of Vibration Engineering Research; Nanjing University of Aeronautics and Astronautics; Nanjing 210016; China
Abstract： The estimation of frequency response functions (FRFs) is necessary in MIMO (Multiple Input and Multiple Output) random vibration test control. The actual excitation signals for the shaker tables are always not sampled during the vibration test. The FRFs are estimated by the actual response signals and the excitation signals in the computer memory. Because there is a phase lag between the signal in the memory and the actual signal on the shaker table, the response signal is not synchronal with the memory excitation signal. So, it is very difficult to estimate the FRFs with these signals. Based on the relationship between the excitation and the response in linear system and the random decrement technique, a Dual Correlation Method (DCM) is presented in the paper to estimate the FRFs without measuring the actual driving force signals. One only needs to sample the response signals to estimate FRFs. A comparing test between DCM and the convention method which needs to sample the excitation and response signals simultaneously is accomplished on a 3-axis vibration table. The result shows that the presented DCM is correct.
崔旭利;陈怀海;贺旭东;姜双燕. MIMO随机振动试验频响估计中激励和响应的同步方法[J]. , 2012, 31(3): 92-96.
CUI Xu-li;CHEN Huai-hai;HE Xu-dong;JIANG Shuang-yan. Synchronization between excitation and response signals in frequency response function estimation for mimo random vibration test. , 2012, 31(3): 92-96.
2012, Vol. 31 
