基于MDP方法设计的PID控制器在吹塑机中的应用

Application of PID Controller Based on MDP Method in Blow Molding Machine

塑料薄膜制造中吹塑机的张力控制是决定塑料薄膜厚度、强度和质量的一个重要因素。针对吹塑机的张力控制系统的一阶积分时滞模型,提出一种新的基于MDP方法的PID控制器。基于一个假设,即多主导极是正的、稳定的,并且过程控制系统无振荡,同时需要假设非主导的极点或者零点对控制过程的影响不显著。为了提高伺服性能,降低超调量,在PID控制结构中使用了设定点权重参数。控制过程简洁,控制器参数以表达式的形式给出。仿真案例实验结果表明,设计具有良好的追踪性能和调节性能,并且鲁棒性良好,适用于张力控制。

Tension control of blow molding machines in plastic film manufacturing is a key factor in determining the thickness,strength and quality of plastic film.In view of the blow molding machine tension control system of the firstorder integrating time-delay system model,the research puts forward a new PID controller based on MDP method.And the proposed method is based on a hypothesis that the multiple dominant pole is positive and stable without oscillation.Also we need to assume the non-dominant poles or zeros have no effect on the control process.In order to improve the servo performance and reduce the overshoot,the set-point weighting parameter is used in the PID structure.The process of this method is very simple,and the controller parameters are given in the form of expressions.The simulation results show that this method has good tracking performance and regulator performance with good robustness,which is very suitable for tension control.