PHYSICALLY-BASTED ADAPTIVE-CONTROL OF CAVITY PRESSURE IN INJECTION-MOLDING - FILLING PHASE

Cavity pressure plays an important role in determining the quality of injection molded articles. The non-linear and time-varying nature of t he process difficulties in implementing efficient control systems, whi ch usually employ linear, time-invariant design strategies. conversely , advanced control methods, such as self-tuning control, do not provid e physical information about the process. A physically-based adaptive controller has been developed for cavity pressure control during the f illing phase. Different control algorithms, employing different tuning criteria, were implemented on a microcomputer to control the cavity p ressure. Experimental results indicate that this control yields accura te results for the injection molding of polyethylene. The results also show that this method, using the IMC algorithm, is superior to the cl assical optimal controller tuning approach.