Abstract
We consider an electromagnetic suspension system and discuss the design procedure that can stabilize robustly when the mass of object is changed. In this case, model uncertainty can be treated in the so-called structured uncertainty and we will apply two quadratic stabilization design procedures. Especially, we will show that a distribution ratio of uncertainty has an important role corresponding to the wighting matrix in the LQ regulator problem in first design procedure, and propose the quadratic stabilizing mixed sensitive problem which can consider not only the quadratic stabilization but also lower sensitvly performance in second design procedure. We will confirm the validity of this proposed design procedures by nonlinear simulations and experiments.
