高阶加时滞模型的系统频域辨识

Modeling Identification for High Order Process with Time-delay in the Frequency Domain

针对工业控制系统中带有时滞环节的高阶过程对象,由于设计控制器比较困难,文中采用二阶加纯滞后模型的频域辨识方法,通过采样对象的输入和输出数据,分析其频率响应并确定重要频率段。选取若干个重要频率响应点,利用幅频特性估算出系统模型参数,达到模型降阶目的。MATLAB仿真结果表明,文中方法适用于广泛的高阶时滞对象,并具有较好的准确性和鲁棒性。

For the high order process with time-delay in industrial control systems,the second-order plus pure lag model was used to identify the frequency domain because it was difficult to design the controller.By sampling the input and output data of the object,the frequency response was analyzed and the important frequency segments were determined.Several important frequency response points were selected,and the system model parameters were estimated by the amplitude-frequency characteristics to achieve model reduction.The simulation results of MATLAB showed that the proposed method was suitable for a wide range of high-order time-delay objects and had good accuracy and robustness.