Smith预估控制在大滞后加热系统中的应用

Application of Smith Predictor Control for a Temperature System with Large Time-delay

在工业过程中,大滞后系统普遍存在。论文以一实验用加热装置为研究对象,针对该温度控制系统具有大滞后特点,采用串级控制结构结合Smith预估控制器的控制方案。内环采用P控制;外环采用Smith预估器以大幅度降低滞后对控制系统动态性能的影响,结合PI控制,实现系统无静差。实验表明该种控制系统与单回路PID控制相比,具有更优的动态特性。

The large time-delay systems widely exist in industry process. According to the controlled object of the temperature with strong time-delay, a scheme with cascade control and Smith controller is adopted, Smith controller is adopted in outside loop to reduce the influence on dynamic characteristic by large time-delay ,and PI controller is used to eliminate static error. The P controller is used in inside loop. The results demonstrate that the cascade control and Smith controller system is much better than single PID loop control in dynamic oerformance.