Sliding mode control for an active magnetic bearing system subject to base motion

• Published in: Mechatronics (Oxford) Vol. 20; no. 1; pp. 171 - 178
• Main Authors: Kang, Min Sig, Lyou, Joon, Lee, Jong Kwang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2010; Elsevier
• Subjects: Active magnetic bearing; Applied sciences; Base disturbance; Bearings, bushings, rolling bearings; Computer science; control theory; systems; Control theory. Systems; Drives; Electro-optical sight; Exact sciences and technology; Mechanical engineering. Machine design; Modelling and identification; Parameter uncertainty; Sliding mode control; Active magnetic bearing; Base disturbance; Parameter uncertainty; Sliding mode control; Electro-optical sight; Variable structure control; Sliding mode; Stator; Gas bearing; Experimental study; Modeling; Reachability; Closed feedback; Uncertain system; Active system; Magnetic bearing; Moving load; Air gap; Feasibility; Robustness; Localization; Closed loop systems
• ISSN: 0957-4158; 1873-4006
• DOI: 10.1016/j.mechatronics.2009.09.010

This paper describes the application of an active magnetic bearing (AMB) system to levitate the elevation axis of an electro-optical sight mounted on a moving vehicle. In this type of system, it is desirable to retain the elevation axis in an air–gap between magnetic bearing stators while the vehicle is moving. A sliding mode control is applied to increase robustness to model uncertainties and to reduce disturbance responses. To ensure the authority of sliding mode control, model parameter uncertainties of AMB systems are analysed and reachability to sliding surface has been verified. The sliding surfaces are designed such that the poles of the closed-loop system locate at desired locations. The proposed control is applied to a 2-DOF active magnetic bearing system subject to base motion. The feasibility of the proposed technique is verified with experimental results.