| Title |
Nonlinear Controller Design of Active Magnetic Bearing Systems Based on Polytopic Quasi-LPV Models |
| Authors |
이동환(Lee, Dong-Hwan) ; 박진배(Park, Jin-Bae) ; 정현석(Jeong, Hyun-Suk) ; 주영훈(Joo, Young-Hoon) |
| Keywords |
Active Magnetic Bearing (AMB) ; Polytopic Quasi-Linear Papameter Varying (LPV) Systems ; Linear Matrix Inequality (LMI) ; Stabilization ; Nonlinear Systems |
| Abstract |
In this paper, a systematic procedure to design a nonlinear controller for nonlinear active magnetic bearing (AMB) systems is presented. To do this, we effectively convert the AMB system into a polytopic quasi-linear parameter varying (LPV) system, which is a representation of nonlinear state-space models and is described by the convex combination of a set of precisely known vertices. Unlike the existing quasi-LPV systems, the nonlinear weighting functions, which construct the polytopic quasi-LPV model of the AMB system by connecting the vertices, include not only state variables but also the input ones. This allows us to treat the input nonlinearity effectively. By means of the derived polytopic quasi-LPV model and linear matrix inequality (LMI) conditions, nonlinear controller that stabilizes the AMB system is obtained. The effectiveness of the proposed controller design methodology is finally demonstrated through numerical simulations. |