控制系统闭环响应函数的快速辨识

Quick identification of the closed - loop response function in control system

按照控制系统的传统模型，可以建立近似的闭环传递函数．但其阶跃响应中超调量的偏差将明显地与系统的纯滞后时间相关．对于较复杂的对象，若用数值求解法求取整个闭环响应曲线，将很费时．鉴于一般工业控制系统的闭环响应都包含振荡过程．通过理论分析和论证，并利用阶跃响应的前３个幅值，提出了一组能快速辨识闭环响应函数的公式和综合模型，经对３种典型的仿真实例的验证，结果是准确的．此法也适用于发散振荡的情况．

By means of the traditional model of control system, the approximate Closed - loop transfer function can be established. But the deviation of overswing in its step response will be obviously relative to pure dead time of system. With the rather complex object, a lot of time will be needed to find the complete curve of Closed - loop response with the applied math calculus. The Closed - loop response in general industrial control system usually contains oscillation process. By theroetical analysis and demonstration and with the first three peaks of step response, a set of formula and overall model are presented, in which the Closed - loop response function of system can be quickly identificated. The accurate results can be verified through three typical simulative exemples. This method can also be suitable for the situation of divergent oscillation.