In this paper, an indirect approach to the dual-mode adaptive robust controller (DMARC) is proposed, which combines the typical transient and robustness properties of variable structure systems with a smooth control signal in steady state, typical of conventional adaptive controllers, as model reference adaptive controller. The aim of this indirect version, here named indirect DMARC, is to provide a more intuitive controller design, based on physical plant parameters, as resistances, inertia moments, capacitances, and so on, maintaining DMARC properties. In this paper, a stability analysis for the proposed controller and simulations to an unstable second-order plant will be presented.

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Informatics plays an imperative role in the designing and tuning of new control systems strategies, since the computational simulation of such systems is part of the entire process of applying an algorithm on a real environment. This paper presents an alternative to the Proportional-Integrative-Derivative (PID) controller for temperature control in grain drying systems. The PID controller may present undesirable oscillations in the presence of external disturbances associated with agroindustrial facilities, thus demanding a precise and automatic tuning during the entire process. Robust controllers are suitable and recommended for the drying final quality, since the grains are offered a thermal damage reduction when submitted to abrupt temperature variations, as fragility and even crack during processing. Simulation results on an experimental model of a nonlinear robust controller, named Shunt Indirect Variable Structure Model Reference Adaptive Controller (SIVS-MRAC) are shown. Performance results before disturbances and parametric variations are compared with the PID behaviour. 561 B. de Oliveira J., V. A. Fernandes M. and R. L. Teixeira L.. Modeling and Simulation of a Temperature Robust Control in Grain Drying Systems for Thermal Damage Reduction.