Non-Linear Model Based Trajectory Tracking Control for Drying Process of Spirulina Platensis and Red Chili in a Type-Tunnel Dryer

In this paper, a new control strategy for drying process was developed to control the product temperature in a type tunnel dryer. A two-stage control was developed to track the temperature trajectories of product and air using a Bezier curve at different setpoints, i.e., 50 °C for Spirulina platensis and 65 °C for Red Chili. The results demonstrate that the proposed control strategy leverages the heat supplied to the first product to enhance the heating performance of the second product. Furthermore, the use of a nonlinear model ensures that the tracking error tends to zero. Additionally, inherent disturbances in the model were considered in the second stage of the control to track the trajectory of the air temperature. Even when accounting for these disturbances, the control strategy is capable of effectively tracking the trajectory.