Identification of linear time-varying mdof dynamic systems from forced excitation using Hilbert transform and EMD method

An algorithm is developed for the identification of linear time-varying (LTV) multiple degrees-of-freedom systems. It is based on the Hilbert transform and the empirical mode decomposition with forced vibration response data. The proposed identification algorithm is applied to single degree-of-freedom and multi-degrees-of-freedom dynamic systems. Three ideal cases of LTV systems, with smoothly varying, abruptly varying and periodically varying stiffness and damping, are studied to illustrate the capability of the algorithm to track the variations of the system. Simulation results demonstrate the effectiveness and the robustness of the proposed identification algorithm, and the lack of complete orthogonality for any two intrinsic mode functions is one of the sources of error in the identification.