基于灰色预测的模糊免疫PID控制器在板厚控制系统中的应用

Application of Fuzzy Immune PID Controller Based on Gray Prediction in Gauge Control System

针对冷连轧板厚控制系统中存在非线性、时变和时滞等缺点,提出了一种基于灰色预测的模糊免疫PID控制策略。该控制策略借鉴生物免疫系统中的调节作用和模糊推理逻辑可逼近非线性函数的特性,将模糊控制和免疫反馈机理与传统PID控制相结合。同时将灰色预测在线应用,用其预测结果代替被控对象的测量值,与给定输入的偏差及偏差变化率作为模糊控制器的输入来调整PID控制器的参数。仿真及现场试验结果表明,该控制策略具有超调量小,调整时间短,抗干扰能力和鲁棒性强等优点,控制效果优于传统控制方法。

Because the disadvantages of nonlinearity, large time-delay and time-varying existing in gauge control system of cold-continuous rolling sheet, a strategy of Fuzzy-Immune-PID control based on Gray prediction was proposed. Inspired by the control effect of feedback response of biological immune systems and the possibility of approaching non-linear functions with fuzzy rationalizing logic, fuzzy control and immune feedback mechanism was combined with the conventional PID control. Then the gray prediction was put into on-line use to replace the measured value of the controlled object by the prediction results, and errors as well as error variety velocity between prediction result and given input were taken as the inputs of fuzzy controller to adjust parameters of PID controller. Simulation and experiment results indicate that the strategy has characteristics of low overshoot, short regulating time, strong anti-disturbance ability and great robustness and has well control performance compared with conventional control method.