纸浆浓度的模糊-Smith及PID复合控制

针对纸浆浓度控制系统具有大纯滞后和模型不确定的特性,提出了将模糊-Smith控制和PID控制相结合的控制策略,用Smith预估算法克服纯滞后,利用模糊控制来提高系统的鲁棒性,而在稳态阶段则切换为PID控制来提高控制精度.经过对纸浆浓度控制系统的仿真研究,结果表明模糊-Smith及PID复合控制既具有模糊控制较强的鲁棒性,又具有PID控制精度高的特点,尤其是在模型失配时表现出良好的稳定性和鲁棒性,对于大时间滞后系统是一种实用而简便的控制策略.

Fuzzy-Smith and PID Complex Control of Pulp Concentration

To cope with the problems of uncertainty and delay for pulp concentration control,fuzzy-Smith method combined with PID control is proposed.Smith predictor algorithm compensates for the time delay and fuzzy control is used to enhance the robustness of the system.PID algorithm is used to improve the precision of the system when it is steady.Through the simulation of pulp concentration system,the result of the simulation shows that fuzzy-Smith and PID complex control not only has a better characteristic of robustness of fuzzy control,but also has high precision of PID control.Especially under the condition of unmatched model,it also shows the better characteristic of stability and robustness.It is an appropriate and simple control method for the system with pure time delay.