Optimizing industrial oven temperature uniformity: A model predictive control framework with rapid control prototyping

Industrial ovens are pivotal in manufacturing, particularly food processing, electronics, and materials fabrication. In this context, temperature control algorithms must satisfy demanding control specifications, among which: setpoint tracking, disturbance rejection, energy saving, and actuator limitations. Specifically, one of the critical challenges in industrial ovens is achieving a uniform temperature distribution within the oven cavity, especially in the presence of disturbances. This paper focuses on a particular kind of industrial ovens installed in shrink tunnels, which are employed in manufacturing applications for polymeric packaging. In these applications, temperature uniformity is a key factor in determining the quality of the packages resulting from the heat shrinking process, making it a major concern. Consequently, we propose three Model Predictive Control (MPC) strategies for shrink tunnels aimed for temperature uniformity: an MPC for tracking (as a baseline), and two zone-based MPCs that steer the oven temperatures towards either a fixed or an adaptive range rather than a single target point. All control strategies are thoroughly and experimentally validated on a shrink tunnel workbench installed in a manufacturing facility. Specifically, we adopt the Rapid Control Prototyping (RCP) paradigm to speed up controller implementation and performance assessment. Experimental results demonstrate that the zone-based MPC strategies significantly improve the temperature uniformity within the oven cavity compared to the MPC for tracking formulation.