基于期望控制函数频率特征的解耦多变量控制

Decoupling Multivariable Control Based on Frequency Characteristics of Expected Control Function

摘要:

提出一种简单的解耦多变量系统比例积分微分(PID)控制器设计方法;首先,将多变量过程前馈解耦为多个独立单回路系统,利用解耦器对角环节保证解耦器的稳定性和可物理实现性;其次,针对每个已解耦单回路系统,提出同时考虑设定值跟踪、扰动抑制和鲁棒稳定性要求的期望闭环传递函数,由此得到期望控制函数,并基于期望控制函数的频率特征快速获取PID控制参数;最后,示例了解耦多变量控制器的设计过程;仿真结果表明该解耦PID设计法对一般多变量时滞过程的控制是有效的。

Abstract:

A decoupling multivariable control system and its proportional-integral-derivative (PID) controllers are proposed. First, multiple sigle-input and single-output (SISO) processes are obtained through feedforward decoupling for interacting multi-input and multi-output (MIMO) process. This feedforward decoupler can ensure itself stability and realizability by its main diagonal elements. Second, multiple desired closed-loop transfer functions are selected in consideration of setpoint tracking, disturbance rejection and robust stability of each single loop system in simultaneously. With this, the expected control functions are obtained and its frequency characteristics are used to determine the PID parameters respectively. At last, examples are used to illustrate the proposed design method. Simulation results show that the proposed approach of decoupling control for general multivariable processes with time delay is effective.