串级控制系统模型矩量辨识方法

Identification Method of Moments for Cascade Control Systems

针对现代工业过程串级控制系统的对象模型辨识问题,提出一种新的基于系统正常运行数据的闭环矩量辨识方法。该方法仅需得到一次设定值变化的正常运行数据,采用梯形积分的方法计算得到传递函数两次求导的值,再运用极小化误差方法和最小二乘法对数据拟合,从而解得二阶含滞后模型的四个未知参数,进而辨识出串级控制系统的内环和外环模型。最后,通过MATLAB进行多次仿真实验。仿真结果表明,该辨识方法不仅具有普适性和极高的辨识精度,而且对噪声信号不敏感,具备良好的鲁棒性。

Aiming at the plant model identification of cascade control system of modern industrial process,a closed-loop moment identification method based on the normal operation data of the system is proposed.This method only needs to obtain the normal operation data of one set value change.The trapezoidal integration method is used to calculate the value of the two derivation of the transfer function.Then,the minimum error method and the least square method are used to fit the data,so as to solve the four unknown parameters of the second-order model with lag and the inner and outer loop models of the cascade control system can be identified.Finally,several simulation experiments are carried out by MATLAB.The simulation results show that the proposed identification method not only has universality and high accuracy,but also is insensitive to noise signal and has good robustness.