纯滞后对象的鲁棒状态优化设计方法

A robust and optimal design for dead-time processes with state feedback

纯滞后对象是一种很难控制的对象。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,并选择一种近乎理想的最优低通滤波器作为串级系统内外环的参考模型,并引入状态观测器,大幅度地减少状态的检测数量;采用内外环系统的协调设计,拉开内外环回路的操作频率;同时引入伺服补偿器,大大提高系统的鲁棒性。通过具体的工业对象进行仿真实验,证实该方法相当有效。

A pure dead-time process is difficult to control.A kind of cascade control system with state feedback for pure dead-time processes is presented in this paper.With this control method,the dead-time plants can posses good control performance.First,the pure dead-time factor is fit for a rational polynomial with numerical approximation.Then a nearly ideal optimal low-pass filter is used as a reference model for the interloop and outloop compensation of the cascade control system.A state observer is also designed to reduce the detecting number of system states.The codesign of the system interloop and outloop is used by rationally adjusting the operation frequencies.A servo-compensator is also designed to greatly improve the robustness of the system.The simulation results show that the method is quite effective.