基于Smith预估的纯滞后系统的控制

针对具有纯时间滞后的系统,分析了PID算法、Dahlin算法和Smith预估算法的特点,指出只要对Smith预估控制器进行适当的设计,就能等效于Dahlin算法.提出了利用Smith预估器补偿时间滞后,按Dahlin算法原理设计控制器的Dahlin～Smith算法和将Smith预估系统结构变换为内模控制器(IMC)结构,再按内模控制原理进行控制器设计的IMC-Smith算法.在模型匹配和失配情况下进行了仿真研究,结果表明,所提出的新控制算法在系统模型不精确的情况下,具有更好的稳定性和鲁棒性,对于大时间滞后系统是一种比较实用的控制方法.

Control of the System with Pure Time Delay Based on Smith Predictive Algorithm

The characteristic of some control algorithms for the system with pure time delay is analyzed.They are PID, Dahlin and Smith predictor algorithm.The analysis shows that Smith predictor algorithm is equivalent to Dahlin algorithm if Smith predictor controller is designed properly.Two new algorithms are discussed.One is Dahlin-Smith algorithm which is designed according to the principle of Dahlin algorithm on the base of Smith predictor.Another one is IMC-Smith algorithm whose Smith predictor controller is designed according to IMC structure.The simulation of these control algorithms is studied under the condition of model matching and model unmatching.The result shows that the new control algorithms have a better stability and robustness.And they are appropriate control methods for the system with pure time delay.