Implementação de técnicas de controle avançado a uma planta piloto de controle de vazão e temperatura de ar

Abstract

It is presented in this work the design of an advanced control system, applied to a pilot plant in which air flowrate and temperature are the controlled variables. It consists of the description of the process of insuflated air heating control, mathematical modeling, definition of control strategies, design of PI(D) controllers and direct feedforward, as well as adaptive minimum variance controllers with adaptive feedforward action. Considerations about practical implementation of the control system are made and, finally, an analysis of final results in the pilot plant is presented. The air flowrate and temperature control system is in fact the pilot plant that is used to apply advanced control strategies wich will be described in detail. The manipulated and controlled variables of the control system will be evaluated. Considerations about the disturbances present in the process will also be relevant. Step responses are used in the development of the mathematical modeling, in particular, the Percent Complete Response method. First order plus dead time models and combined models are estimated. The parameters estimation technique enforced in the adaptive control algorithms will be the Recursive Least Square wiht forgetting factor. The Direct Synthesis method was used to design the PI(D) controllers. Then, PI(D) controllers with ``anti-windup'' scheme and feedforward compensation were used. Generalized minimum variance controllers design are also proposed, as well as, the adaptive feedforward compensation. Simulation and practical results are presented to show the efficacy of the proposed control strategies.