浊度大时滞过程的预测自抗扰控制器设计

待滤水浊度过程涉及复杂的物理、化学反应,具有明显的大时滞、不确定性和干扰多等特点,一直是制水行业公认的难控系统.针对其干扰多和不确定性特点,采用自抗扰控制来主动实时估计扰动并进行补偿;针对其大时滞特点,采用预测控制对输出提前预报来弥补大时滞系统中的信息不及时,从而得到一种既具信息预估又具主动补偿总扰动的预测自抗扰控制器.本文重点分析了预测自抗扰控制器的性能,给出了时滞系统在该控制器作用下的开环频率参数求取方法及简单实用的参数整定公式,最后将其与几种常见控制器进行了仿真比较.仿真结果表明:预测自抗扰控制器具有良好的抗扰恢复能力和设定值跟踪能力,且参数整定容易,具有简单、好用且有效等特点,为该控制器的工业化应用提供了积极的指导作用.

Design of predictive active disturbance rejection controller for turbidity

Turbidity process, which involves complex physical and chemical reactions, is difficult to control for engineers due to its characteristics of large time-delay, uncertainties and disturbances. For this reason, a novel predictive active disturbance rejection control (PADRC) strategy is proposed, which owns the advantages of predictive control and active disturbance rejection control (ADRC). The ADRC part aims to estimate the total disturbances, and cancel from the control output to deal with the uncertainties; the predictor part is adopted to predict the output to compensate the lack of data resulted from large time delay. The performance of PADRC has been analyzed in detail. In addition, a general method to solve the open-loop frequency parameters is provided, as well as the parameter tuning equations. Finally, simulation-based comparisons of PADRC and three regular control approaches has been made. The results show that PADRC has a better performance, especially in set point tracking and disturbances rejecting. Moreover, PADRC is simple, practical and easy to tune parameters, thus providing guidelines for industrial applications of similar systems.