Title: Adaptive controller for stabilisation of rotational motion of a vertical shaft magnetic bearing

Authors: A.A. Abouelsoud; Abdelfatah M. Mohamed

Addresses: Department of Mechatronics and Robotics Engineering, School of Innovative Design Engineering, Egypt-Japan University of Science and Technology (EJUST), Egypt; Department of Electronics and Communication Engineering, Cairo University, Giza, Egypt ' Department of Mechatronics and Robotics Engineering, School of Innovative Design Engineering, Egypt-Japan University of Science and Technology (EJUST), Egypt; Department of Electrical and Electronics, Assiut University, Assiut, Egypt

Abstract: This paper proposes an adaptive controller to stabilise the rotational motion of a vertical shaft magnetic bearing. The gyroscopic coupling between the vertical and horizontal motion depends on rotational angular velocity and for variable speed applications, this velocity is considered an unknown parameter. Moreover, there are uncertainties in the mechanical and electrical parameters of the magnetic bearing model. This motivates the application of adaptive control to magnetic bearing system. The proposed adaptive controller is a model reference controller which uses the air gap measurement only as a feedback signal. The adaptive control system is proven to be globally asymptotically stable using Lyapunov direct method. Simulation results show the effectiveness of the proposed method.

Keywords: magnetic bearings; adaptive control; model reference control; MRC; Lyapunov direct method; global asymptotic stability; controller design; rotational motion; vertical shaft bearings; uncertainty; gyroscopic coupling; rotational angular velocity; variable speed; air gap measurement; simulation.

DOI: 10.1504/IJMIC.2015.068864

International Journal of Modelling, Identification and Control, 2015 Vol.23 No.2, pp.154 - 163

Received: 27 Mar 2014
Accepted: 02 Jun 2014
Published online: 16 Apr 2015 *

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