基于变论域模糊PID的纸浆浓度控制系统研究

Pulp Consistency Control System Based on Variable Universe Fuzzy PID

关键词:  纸浆浓度  变论域  模糊控制  Simulink

Key Words:pulp concentration  variable universe  fuzzy control  Simulink

摘要:针对传统模糊PID控制器因变量论域、比例因子、量化因子等参数设置固定不能实现纸浆浓度精确控制的问题，本课题提出将变论域思想与模糊PID控制相结合的变论域模糊PID控制算法。首先在模糊控制器中引入论域伸缩因子使模糊控制器输入输出变量的论域范围随纸浆浓度误差及误差变化率进行伸缩调整，以提高模糊控制器的控制精度；然后利用变论域模糊控制器对PID的3个参数进行调整，实现PID控制器的实时在线整定。仿真结果表明，变论域模糊PID控制算法可以有效地克服纸浆浓度控制过程存在的时变性、多干扰、时滞性缺点，能够实现纸浆浓度控制的稳定性和精确性。现场实际应用表明，应用变论域模糊PID控制算法的控制系统可将上浆浓度误差控制由±0.3%降为±0.025%以内。

Abstract:The traditional fuzzy PID controller cannot achieve precise control of pulp consistency due to fixed parameters such as variable universe， scale factor and quantization factor. A variable universe fuzzy PID control algorithm combining variable universe theory with fuzzy control PID control was proposed. In order to improve the control precision of the fuzzy controller， the domain range of the input and output variable of the fuzzy controller was adjusted in the fuzzy controller by introducing the domain scalability factor in the fuzzy controller. The variable universe fuzzy controller was used to adjust three parameters of PID to realize real-time online tuning of PID controller. The simulation results showed that the variable domain fuzzy PID control algorithm could effectively overcome the time-varying， multi interference and time-delay defects in the pulp consistency control process， and could achieve the stability and accuracy of pulp consistency control. Field application could control pulp consistency in the error within ±0.025%， indicating that the algorithm was feasible and adaptable．