基于阶跃响应曲线特征的线性系统辨识方法研究

Study on Identification Method for Linear System Based on the Feature of Step Response Curve

针对阶跃响应法建模的局限性,提出一种基于阶跃响应曲线特征的线性系统辨识方法。高阶线性系统可由多个一阶与二阶典型环节并联而成,分析典型环节各参数对曲线形状影响的规律,并依据其调整各参数值,以典型环节并联模型的拟合曲线逼近实际的阶跃响应曲线,从而得到系统的传递函数。另外,借助Matlab图形用户界面(GUI)平台,开发了辨识软件以验证该算法的正确性与可行性,实验结果表明,该方法辨识精度高,对于复杂控制系统建模具有一定的参考性。

In order to solve the limitations of step response identification modeling, an identification method is presented for linear system based on the feature of step response curve. According to the theory that the typical first-order and second-order components can comprise a high order linear system in parallel form, the influences of parameters on the shape of the curve are analyzed. These laws are used to adjust the values of the parameters in the typical components to make the fitted curve close to the actual step response curve, and the transfer function is obtained. In order to validate the feasibility and correctness of the algorithm, an identification software is developed with the help of Matlab Graphical User Interface( Matlab GUI). The simulation results show that this method is reliable and accurate, and has certain reference value for the modeling of complicated control system.