多变量时滞过程解耦Smith控制

针对实际工业生产中常见的多输入多输出时滞过程,构造多变量Smith预估控制结构,提出基于对象模型伴随矩阵的解耦器设计方法.通过对解耦后对象的幅频和相频特性分析,获得对象的简化一阶数学模型.根据Smith预估控制结构闭环特征方程的特点,利用Butterworth滤波器极点配置的原理,对解耦后的多变量时滞过程设计PI控制器.结合实际过程中常见的不确定性,分析了控制系统保证鲁棒稳定性的充要条件.最后以实例验证了本文所提方法的优越性.

Decoupling Smith control for multivariable system with time-delays

The decoupling Smith control method is presented for multi-input-multi-output system with time-delays which are often encountered in practical engineering. A new method for designing the decoupler based on the adjoint matrix of the multivariable system model with time-delays is proposed. By analyzing the amplitude-frequency and phasefrequency characteristics of the decoupled model, the decoupled model is reduced to a first-order model with time-delay. According to the closed-loop characteristic equation of Smith predictor structure, a PI controller is developed by using the principle of pole assignment for Butterworth filter. Sufficient and necessary conditions for robust stability are derived for adaptive and multiplicative uncertainties commonly occurred in practice. Simulation results show the superiority of the proposed method.