Controle H-infinito não-linear aplicado em sistema de levitação magnética: projeto e implementação em DSP de ponto-fixo.

Abstract

Electromagnetic suspension systems are inherently nonlinear and often face hardware limitation when digitally controlled. The goal of this thesis is to present theoretical and practical aspects during the nonlinear H ∞ control applied on an electromagnetic suspension system. The first contribution is the design of a nonlinear H ∞ controller, including dynamic weighting functions, obtained from a linear H ∞ controller. Just as in the linear case, this dynamic weighting functions provide the disturbance and noise sensor rejection, robustness improvement, among other specifications. The second contribution is to present a procedure able to translate a floating-point algorithm into a fixed-point algorithm by using l ∞ norm minimization due to conversion error, which was then implemented into a 32-bit fixed-point DSP. Experimental results are also presented, in which the performance of the nonlinear controller is evaluated specifically in the initial suspension phase.