Smooth Adaptive Robust Temperature Control of a Seed Drying System

This paper addresses the problem of maintaining the temperature precisely tuned inside a seed drying system, in order to avoid thermal damage to that sensible biological entity and thus guarantee the right conditions for storage. This objective is achieved through an adaptive robust technique, known as Shunt Indirect Variable Structure Model Reference Adaptive Control (SIVS-MRAC), which has shown to be insensitive to external disturbances and unmodeled dynamics, although it presents a high frequency switching control signal that might be undesirable or even not compatible with some actuators. Here, besides the low control signal magnitude, control signal smoothness is obtained by using output error dependant linear regions and the equivalent control method. Simulations results are presented comparing the usage of such a technique.