Temperature control of an innovative aluminium-steel molds induction preheat process placed on automated laser guided vehicles

In the production of plastic components based on injection molding, like shoe sole manufacturing, the temperature control and the on-line process optimization are important issues in order to preserve the quality of the plastic components and improve the time performance, while maintaining high product quality. This research proposes an induction preheating control technique based on Model Predictive Controller (MPC) for a steel-aluminium mold for production of soles, performed on an automated Laser Guided Vehicle (LGV) with an innovative induction heating functionality. A thermal model has been studied using a finite-difference approach to describe the mold heating system. The resulting system has been simulated using Simulink/MATLAB. Then, three types of controllers have been modelled in the proposed simulation workflow, in order to compare the different behavior of the system. Due to the high mold thermal inertia, which increases the mold temperature even if the control system turns off the thermal power, innovative controllers are needed in order to track the desired temperature setpoint. The comparison with standard industrial controllers, based on PI and PID controllers, shows the effectiveness of proposed solution.