Proposta de controlador robusto por modelo de referência para controle de nível de líquido em tanque

Abstract

One of the most common processes in modern control is the liquid level. Traditionally, the designers used the conventional PID (Proportional–Integral–Derivative) controller. However, the liquid level’s behavior is nonlinear, and in this way, the PID controllers only show a good performance near a determined operating point. This restriction produces limitations in the improvements to the system’s behavior, which compromises the economic benefits. As alternatives to the conventional PID, the researchers proposed several nonlinear controllers. But, some of them show very complex implementations in a real scenario. Thus, in this work, we propose a controller to the liquid level which does not require an operating point, has a simple design and implementation, is robust to external disturbances, uncertainties, and variations in the parameters. The work, beyond the proposed controller, presents results of stability analysis and simulations.