Setting of Injection Velocity Profile via an Iterative Learning Control Approach

Injection velocity is an important variable that affects the quality of injection molded products. Profiling the injection velocity to keep a constant melt-front-velocity inside the mold throughout the filling to ensure a uniform part is the purpose of this work. Based on a transducer designed in a previous work, the melt-front-position is measured online. An iterative learning control system, designed as the outer loop controller in a cascade fashion, is used to solve the optimization problem of setting the injection velocity profile. Experiments show that proposed system works well in ensuring a uniform melt-front-velocity when filling molds with varying geometrical shapes, without the necessity of a physically-based process model. Copyright © 2002 IFAC