纯滞后系统的状态反馈优化设计方法

Optimization Design Based on State Feedback for Pure Dead-time Processes

针对纯滞后对象,提出一种串级双环状态反馈控制方式,使这种对象获得较理想的控制品质。系统的设计方法包括:采用数值逼近方法将对象拟合成有理多项式,并选择一种优化的期望闭环系统,作为串级系统内外环的参考模型;根据串级内、外环不同结构分别采用开环和闭环校正,并引入状态观测器,大幅度地减少状态的检测数量;同时采用内外环系统的协调设计,拉开内外环回路的操作频率,有利于提高系统的鲁棒性。通过工业过程中的纯滞后对象进行仿真实验,证实本方法相当有效,系统动态性能和抗干扰能力明显增强。

A kind of cascade control system with state feedback is presented for pure dead-time processes. With this control method, the dead-time plants can possess good control performance. First, the pure dead-time factor is fit to a rational polynomial with numerical approximation. Then an optimal expected closed-loop system is used as reference model for interloop and outloop compensation of the cascade system. The state observer is also designed to reduce the detecting number of system states. The codesign of the interloop and outloop of the system is also used by rationally adjusting the operation frequencies to improve the robustness of the system. The simulation results of an industrial process show that the method is quite effective.