Projeto dos controladores PID e H-infinito nas abordagens 1-DOF e 2-DOF para o sistema de levitação magnética

Abstract

This work highlights the design of the PID and H-infinity controllers in the 1-DOF and 2-DOF approaches to the magnetic levitation system, being evaluated in function of the nominal and robust performance and stability provided to the plant. MAGLEV is a SISO system attractive to the control domain due the open-loop instability and nonlinearities, which make difficult your stabilization by the controller. Its mathematical model is described as a function of coil dynamics’ approximations and linearized, in order to become the basis for the controllers’ design. The experimental results were obtained using the MAGLEV plant from Feedback Instruments Ltd, and show that the noise signal has relevance in the system stability, especially when there is a significant PID amplification of this signal in the system. This occurrence combined with the challenge imposed by the nature of MAGLEV are reasons why the use of H-infinity controller, which encompasses, in this case, the model uncertainties based on the linearization parameters, and the design requirements related to the improvement of PID’s performance features. The 2-DOF approach is presented as a solution to the overshoot generated by the 1-DOF controllers in the output signal.