Time-varying system physical parameters identification using the continuous wavelet transform of acceleration response

Based on wavelet theory, continuous wavelet transform algorithm of a function's integration is deduced in this paper. The CWT values of velocity and displacement response signals can be estimated via the above algorithm and by which only the acceleration response of a linear time-varying system is used, and the vibration differential equations can be transformed into linear equations with wavelet expression. Therefore the physical parameters (mass, stiffness and damping) of an arbitrarily time-varying system can be directly determined by solving the linear equations at each moment. Subsequently, a 5 dcgrccs-of-frccdom time-varying model is simulated. With three different kinds of time-varying cases (abruptly, smoothly and periodically), systemic physical parameters arc identified by the proposed identification method using the data with noise. The accuracy, effectiveness and the anti-noise ability of the proposed method arc validated by the numerical results. At last, the influence of the resolution analysis to the identification results and how to choose the scale parameters arc studied.