A Novel Method of Transfer-Function Identification for Unknownsystems

This study proposes a new modeling method for unknown systems. Through this method, the transfer functions can be identified. First, theinput-output data pairs of the unidentified system should be collected. Then, the transfer function's coefficients can be identifiedbased on the errors viathe derivative-free search methods such as GA etc. Here, a second-order transfer function is used in this study. For a second-order transfer function is difficult to approach each system, a plurality of transfer functions may be used depending on the precise requirement. Finally, following the previous steps, the other transfer function can be found in succession. In order to confirm the effectiveness of this proposed method, an electromagnetic flywheel (EF) system is used in this study. Such kinds of systems are always with manyuncertainties as nonlinear electromechanical coupling and electromagnetic saturation, etc. They are difficult to modeling via traditional mathematic ways. In this study, the data pairs of EF system is collected by experiments. By assessing the results of the proposaland experimental data shows that this method is feasible to any unknown systems.