Classic Controllers Design Applied to Temperature Control for a Plastic Thermoforming Machine

Abstract

The present document describes the methodology used for the design and implementation of a temperature control system for the oven of a plastic thermoforming machine. This work departs from the utilization of graphics methods for the approximation of the transfer function of the plant using experimental data. The best-obtained model was used for the designing of a proportional-integral (PI) classic controller and classic PI no-lineal with anti-windup. The PI controller with anti-windup effect presented a suitable control action over the plant, which was combined with an AC/AC converter by integral cycle for the control of the process variable. Evaluation testing on the control system showed a temperature variation in the oven lower than ${\pm 2}$ °C. Even more, the application of this work on the real plant contributed for improvement of the dimensional stability of final products in 81.82%.