Unity Sliding Mode Controller Design for Active Magnetic Bearings System

Active Magnetic Bearings (AMBs) are progressively being implemented in a wide variety of applications. Their exclusive appealing features make them suitable for solving traditional rotor-bearing problems using novel design approaches for rotating machinery.  In this paper, a linearized uncertain mod...

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Bibliographic Details
Main Authors: Safanah M. Raafat, Ass. Prof. Dr., Shibly Ahmed Al-Samarraie, Ass. Prof. Dr., Ali M. Mahmood, Instructor
Format: Article
Language:English
Published: University of Baghdad 2015-06-01
Series:Journal of Engineering
Subjects:
Online Access:http://joe.uobaghdad.edu.iq/index.php/main/article/view/416
Description
Summary:Active Magnetic Bearings (AMBs) are progressively being implemented in a wide variety of applications. Their exclusive appealing features make them suitable for solving traditional rotor-bearing problems using novel design approaches for rotating machinery.  In this paper, a linearized uncertain model of AMBs is utilized to develop a nonlinear sliding mode controller based on Lyapunov function for the electromechanical system. The controller requires measurements of the rotor displacements and their derivatives. Since the control law is discontinuous, the proposed controller can achieve a finite time regulation but with the drawback of the chattering problem. To reduce the effect of this problem, the gain of the unite vector term is evaluated as a function to state variables. As a result the proposed discontinuous controller regulates the state to the origin in a finite time in spite of the uncertainty in system model and the presence of external disturbances. These results are demonstrated via numerical simulations. In addition the chattering in system response in these results is within the acceptable range.
ISSN:1726-4073
2520-3339