大时滞系统中Smith控制算法改进与应用

Improvement and Application of Smith Control Algorithm in Large Time Delay System

针对在难以得到精确数学模型的大时滞系统中,由于时滞时间动态变化,导致常规Smith预估器稳定性差和超调量大的问题,提出一种改进型模糊自适应PID-Smith预估控制算法。该方案在常规Smith预估器的基础上,将模糊自适应PID控制器作为系统控制器,并引入了内反馈和一阶滤波器,抑制了时滞变化产生的系统振荡。仿真实验表明:在系统滞后时间多变的情况下,该方案在在一定程度上增强了系统的稳定性、减少了超调量,具有较好的控制效果。

Aiming at the accurate mathematical models are difficult to obtain in large time delay systems,the conventional Smith predictor has poor stability and large overshoot due to the dynamic change of the delay time,an improved fuzzy adaptive PID-Smith predictor that based on the PID-based Smith predictor is proposed,with a fuzzy adaptive PID controller as the system controller.In additional,a feedback loop and a first-order filter are introduced into the suppresses system oscillation caused by time-lag changes.The simulation results show that in the case of variable system lag time,to some extent,this scheme increases the stability of the system and reduces the amount of overshoot,which has a good control effect.