Fuzzy-PID在反重力铸造液面加压控制系统中的应用

由于反重力铸造过程的时滞性、不确定性、复杂性，难以建立精确的数学模型。因此采用不依赖于数学模型的PID控制算法，而传统PID存在动态性能差、稳定恢复时间长、容易出现超调的缺点。为了实现对复杂系统的精确控制，引入Fuzzy控制，将二者结合起来，设计了Fuzzy-PID混合控制算法。该控制算法继承了PID控制无静差、静态性能好的特点，同时又兼有Fuzzy控制适应能力强，动态性能好的优势。实践证明，该控制算法对参数变化适应性好，抗干扰能力强，适合应用在反重力铸造液面加压控制系统中，并取得了良好的控制效果。

Application of Fuzzy-PID Controller in Counter-Gravity Casting Filling System

It is hard to build a precise math model for counter-gravity casting process for its time lag, uncertainty and complexity. Therefore, PID controller which does not depend on math model is used. However, there are some problems in conventional PID, such as poor dynamic performance, long restoring time and excess adjustment. In order to satisfy higher control performance requirement, Fuzzy control is introduced and combined with PID control. This algorithm not only inherits good static stability of PID, but also has the advantage of strong adaptability and good dynamic stability in Fuzzy control. It has been proved that this kind of algorithm shows excellent adaptability against variations of system parameters and external disturbances, which is suitable to the counter-gravity casting, and gets good control effect.