2005 Volume 36 Issue 5 Pages 115-121
Injection molding machines are widely used in industrial applications. The velocity of injection process and the pressure of dwelling process must be controlled with all products; however, such control is very difficult. In fact, the tuning of the controller parameters needed for high quality or multi-objective production takes a long time and requires a high level skill from the professional field engineer. The tuning can be seen as a pursuit of unknown plant parameters.
This study uses a model reference adaptive control (MRAC) strategy to control the injection molding machine. This method can accommodate the unknown plant parameters and tune controller parameters to make output track a desired reference signal. In this first report, we derive the mathematical models and design, separately, adaptive velocity and pressure controllers for the model circuit used to simulate previous two processes. We then performed and evaluated the hybrid MRAC experiment and process MARC. We also examine the robustness of the proposed controller under parameter change, e.g., nozzle clogging, contraction of molded object, etc. The results confirm the proposed method's efficiency and robustness.
