Fixed-Point DSP Implementation of Nonlinear H∞ Controller for Large Gap Electromagnetic Suspension System

Abstract

Electromagnetic suspension systems are inherently nonlinear and, when digitally controlled, frequently face hardware limitations. The main contributions of this paper are: the design of a nonlinear H∞ controller, including dynamic weighting functions for such a system and the presentation of a practical procedure to implement this controller on a fixed-point DSP. Experimental results are also presented, in which the performance of the nonlinear controller is evaluated specifically in the initial suspension phase, when the starting gap is too far from the equilibrium working gap.