Parameter Identification of Resonant System Based on Step Response Method

A lot of 3practical systems, such as mechanical system, vehicle shockproof system, the seismic system of the building etc, can be simplized as a resonance system, which usually involves multiple components. There are still some unknown parameters in the practical application of the resonance system, and there are also some external disturbances. The coordination between each component cannot be completely idealized. Hence, in this paper, an experimental platform of resonant system was designed and bulit, and the system identification method based on the step response method is presented for the system. By analyzing the mechanical mechanism of the resonance system, the mechanism model of the system is built using the Lagrange method. Then the step input signal suitable for the resonance system test is designed, the corresponding experimental data is collected, and the model parameters are identified by the step response nonlinear fitting method. Finally, the step response based on the identified transfer function was compared with the actual experimental data, and the validity of the identification was verified. The results shows that the step response method has a better identification fitting degree than the transfer function method, and the model has a higher identification accuracy. The presented identification method in this paper provides a theoretical basis for improving the performance and design efficiency of the controller.