System identification of closely spaced eigenvalues system in coupled structure

Abstract

The closely spaced eigenvalue system is observed in a lot of coupled structures. In this system, there is difficulty of system identification in order to contain the beating wave. In this paper, system identification method of the closely spaced eigenvalue system is investigated. The algorithm of system identification is derived using the virtual symmetry two-degree-of-freedom model. In particular, the update algorithm is derived multi-variable Newton method, using the objective function based on the impulse response function of auto-frequency response function. The numerical simulations are conducted in terms of the observation noise. As a result, our proposed algorithm showed the robustness against the measurement noise and the noise of the initial values. Moreover, experimental identification is conducted using the actual pipeline rig. The estimation result of auto-frequency function denotes the good agreement with the experimental result.