PID-DMC算法及其在液位控制系统中的应用

提出了一种新的带PID校正环节的DMC算法，论述了其原理并将其应用于实际液位控制系统，实现了系统在模型失配明显的情况下对二阶液位对象的有效控制。由于控制阀的非线性特性使得本实验中的液位对象具有时滞弱非线性特性，常规DMC算法控制存在明显的模型失配问题并影响了系统的控制性能。为此在常规DMC算法中引入PID环节，从而得到了一种新的PID—DMC算法。实验结果表明该算法能有效改善系统在模型失配情况下的控制性能，且算法简单易行，在线计算量小。

PID-DMC Algorithm and its Application to the Water-level Control System

A dynamic matrix control (DMC) algorithm with PID correction strategy is presented. The proposed PID-DMC algorithm can effectively control the second-order water-level plant at the presence of apparent model mismatch. Due to the nonlinear feature of the control valve, the water-level plant in this experiment can be described with a feeble nonlinear system with pure time-delay. So there exists model mismatch problem, and the system control performance is affected when using general DMC algorithm. Therefore, a PID-DMC algorithm is proposed when introducing PID algorithm to the general DMC algorithm to overcome model mismatch. The experiments show that the proposed algorithm is effective and easy to implement with less online computation work.