Dynamic Modelling and Performance Optimization-Based Sliding Mode Control of Process Drying in a Convective Tunnel Dryer

In this work, we thoroughly investigate the use of sliding mode control for nonlinear systems, specially its application for the control of dryer designed for drying food products. A dynamic model of the drying process has been developed, experimental measurements presented in this paper are established for different values of drying air temperature and drying air velocity. Two scenario of sliding mode control applied to the hybrid tunnel dryer has been assessed through simulations. At first, a nonlinear sliding mode control with first order sliding surface was tested. In front of the insufficient performance of this control in terms of the presence of chattering phenomenon and static error, it was decided to apply a nonlinear sliding mode control with PI sliding surface. Simulation results show that this latter control approach can obtain excellent control performance with no chattering problem, reducing of static error and a good tracking of trajectory.