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Showing papers by "Abdul Rashid Husain published in 2008"


Journal Article
TL;DR: In this article, a few chattering-free Sliding Mode Controllers (SMC) are proposed to stabilize an AMB system with gyroscopic effect that is proportional to the rotor speed.
Abstract: In this paper, a few chattering-free Sliding Mode Controllers (SMC) are proposed to stabilize an Active Magnetic Bearing (AMB) system with gyroscopic effect that is proportional to the rotor speed. The improved switching terms of the controller inherited from the saturation-type function and boundary layer control technique is shown to be able to achieve bounded and asymptotic stability, respectively, while the chattering effect in the input is attenuated. This is proven to be advantageous for AMB system since minimization of chattering results in optimized control effort. The performance of each controller is demonstrated via result of simulation in which the measurement of the total consumed energy and maximum control magnitude of each controller illustrates the effectiveness of the proposed controllers.

25 citations


Journal Article
TL;DR: In this paper, an active magnetic bearing (AMB) system with varying rotor speed is considered and a H2-based sliding surface is designed which bound the mismatched parts.
Abstract: In this paper, application of Sliding Mode Control (SMC) technique for an Active Magnetic Bearing (AMB) system with varying rotor speed is considered. The gyroscopic effect and mass imbalance inherited in the system is proportional to rotor speed in which this nonlinearity effect causes high system instability as the rotor speed increases. Transformation of the AMB dynamic model into regular system shows that these gyroscopic effect and imbalance lie in the mismatched part of the system. A H2-based sliding surface is designed which bound the mismatched parts. The solution of the surface parameter is obtained using Linear Matrix Inequality (LMI). The performance of the controller applied to the AMB model is demonstrated through simulation works under various system conditions. Keywords—Active Magnetic Bearing (AMB), Sliding Mode Control (SMC), Linear Matrix Inequality (LMI), mismatched uncertainty and imbalance.

5 citations


Journal Article
TL;DR: In this paper, a sliding mode control (SMC) design method is proposed in which the sufficient condition that guarantees the global exponential stability of the reduced-order system is represented in Linear Matrix Inequality (LMI) and a new chattering free control law is established such that the system states are driven to reach the switching surface and stay on it thereafter.
Abstract: In this paper, stabilization of an Active Magnetic Bearing (AMB) system with varying rotor speed using Sliding Mode Control (SMC) technique is considered. The gyroscopic effect inherited in the system is proportional to rotor speed in which this nonlinearity effect causes high system instability as the rotor speed increases. Also, transformation of the AMB dynamic model into a new class of uncertain system shows that this gyroscopic effect lies in the mismatched part of the system matrix. Moreover, the current gain parameter is allowed to be varied in a known bound as an uncertainty in the input matrix. SMC design method is proposed in which the sufficient condition that guarantees the global exponential stability of the reduced-order system is represented in Linear Matrix Inequality (LMI). Then, a new chattering-free control law is established such that the system states are driven to reach the switching surface and stay on it thereafter. The performance of the controller applied to the AMB model is demonstrated through simulation works under various system conditions. Keywords—Active Magnetic Bearing (AMB), Sliding Mode Control (SMC), Linear Matrix Inequality (LMI), mismatched uncertainty.

5 citations


01 Jan 2008
TL;DR: In this article, an active magnetic bearing (AMB) system with varying rotor speed is considered and a H 2 -based sliding surface is designed which bound the mismatched parts.
Abstract: — In this paper, application of Sliding Mode Control (SMC) technique for an Active Magnetic Bearing (AMB) system with varying rotor speed is considered. The gyroscopic effect and mass imbalance inherited in the system is proportional to rotor speed in which this nonlinearity effect causes high system instability as the rotor speed increases. Transformation of the AMB dynamic model into regular system shows that these gyroscopic effect and imbalance lie in the mismatched part of the system. A H 2 -based sliding surface is designed which bound the mismatched parts. The solution of the surface parameter is obtained using Linear Matrix Inequality (LMI). The performance of the controller applied to the AMB model is demonstrated through simulation works under various system conditions. Keywords — Active Magnetic Bearing (AMB), Sliding Mode Control (SMC), Linear Matrix Inequality (LMI), mismatched uncertainty and imbalance. I. I NTRODUCTION LIDING Mode Control (SMC) has received great attention in recent years because of its robustness against uncertainties present in system [1], [2] ,[3] and [4]. SMC is a nonlinear control technique that is applicable to a wide range of dynamic system including the linear, nonlinear, multi-input/multi-output, discrete-time and large scale systems. There are many approaches have been reported and considered in the design process of the sliding-mode control law, such that the system is robust or even insensitive to parametric uncertainties and disturbance. In the practical application of SMC, the controller has also been successfully adapted in many forms and applied in numerous real-world applications such as robot manipulator [5], active suspension system [6], magnetic suspension system and magnetic bearings [7][8]. AMB system however is an advance mechatronic system in which it is open loop unstable and inherent high nonlinearity effect. Thus the system requires feedback gain such that the closed-loop system is stable and able to meet required system

2 citations