Design and analysis of position controlled eddy current based nonlinear magnetic levitation system using LMI

Magnetic levitation (Maglev) is becoming a popular transportation topic all around the globe. Maglev systems have been successfully implemented in many applications such as frictionless bearings, high-speed maglev trains, and fast tool servo systems. Due to the features of the instability and nonlinearity of the maglev system, the design of controllers for a maglev system is a difficult task. Literature shows, many authors have proposed various controllers to stabilize the position of the object in the air. The main drawback of these controllers is that symmetric constraints like stability conditions, decay rate conditions, disturbance rejection and eddy-current based force due to the motion of the levitated object are not taken into consideration. In this paper, a linear matrix inequality based fuzzy controller is proposed to reduce vibration in the object. The efficacy of the proposed controller tests on a maglev system considering symmetric constraints and the eddy current based force.