Article

Robust Nonsingular Terminal Sliding-Mode Control for Nonlinear Magnetic Bearing System

Dept. of Electr. Eng., Nat. Central Univ., Chungli, Taiwan
IEEE Transactions on Control Systems Technology (Impact Factor: 2.52). 06/2011; DOI: 10.1109/TCST.2010.2050484
Source: IEEE Xplore

ABSTRACT This study presents a robust nonsingular terminal sliding-mode control (RNTSMC) system to achieve finite time tracking control (FTTC) for the rotor position in the axial direction of a nonlinear thrust active magnetic bearing (TAMB) system. Compared with conventional sliding-mode control (SMC) with linear sliding surface, terminal sliding-mode control (TSMC) with nonlinear terminal sliding surface provides faster, finite time convergence, and higher control precision. In this study, first, the operating principles and dynamic model of the TAMB system using a linearized electromagnetic force model are introduced. Then, the TSMC system is designed for the TAMB to achieve FTTC. Moreover, in order to overcome the singularity problem of the TSMC, a nonsingular terminal sliding-mode control (NTSMC) system is proposed. Furthermore, since the control characteristics of the TAMB are highly nonlinear and time-varying, the RNTSMC system with a recurrent Hermite neural network (RHNN) uncertainty estimator is proposed to improve the control performance and increase the robustness of the TAMB control system. Using the proposed RNTSMC system, the bound of the lumped uncertainty of the TAMB is not required to be known in advance. Finally, some experimental results for the tracking of various reference trajectories demonstrate the validity of the proposed RNTSMC for practical TAMB applications.

0 Bookmarks
 · 
103 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, a simplex type dynamic output feedback variable structure control (VSC) for the stabilization of a nonminimum phase open-loop unstable MBC500 magnetic bearing system is presented. An observer type sliding mode controller is designed for the unstable nonminimum phase system. The performance of the designed sliding mode controller is compared with those of a conventional controller, a controller designed based on analytical interpolation approach, and a fuzzy logic controller (FLC). Simulation results shown that the designed observer type sliding mode controller has superior performance than the other control approaches as it provides the best transient and steady-state responses with less control efforts.
    Intelligent Control and Automation (WCICA), 2012 10th World Congress on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper tries to show some important proper ties of the single input rule modules (SIRMs) connected fuzzy inference systems (FIS), including both type-1 (Tl) and inter val type-2 (IT2) FISs. Three kinds of properties continuity, monotonicity and robustness are explored. First, conditions on the parameters are derived to ensure that the SIRMs connected FISs are continuous and monotonic. Then, a methodology for the robustness analysis of the SIRMs connected FISs are presented. At last, an example is given to show the correctness of the theorems on the continuity and monotonicity and to demonstrate the effectiveness of the proposed methodology for robustness analysis. These results can not only deepen our understanding of the SIRMs connected FISs, but also provide us guidelines for the design of the SIRMs connected FISs.
    FUZZ-IEEE 2011, IEEE International Conference on Fuzzy Systems, Taipei, Taiwan, 27-30 June, 2011, Proceedings; 01/2011
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, a sliding-mode control scheme for LLC resonant dc/dc converter is presented. The proposed controller operates at two fixed switching frequencies with sliding-mode control implementation. The large-signal dynamic model and steady-state characteristics are explored using the extended describing function method. The parameters design and the sliding motions are discussed on the phase plane. The proposed control scheme significantly improves the dynamic response against transient load changes while preserving the closed-loop stability and the attractive features of LLC resonant converter. The simulation and experimental results demonstrate the validity of the sliding-mode control strategy and the fast transient response compared with the conventional PI control.
    IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society; 01/2012