Novel Approximation based Dynamical Modelling and Nonlinear Control of Electromagnetic Levitation System

Abstract

This paper presents the novel design of dynamical model for electromagnetic levitation system (EMLS) as a function of electromagnetic coil inductance in electrical and mechanical subsystems using novel approximation (NA). The proposed inductance model satisfies the requirement of electromagnetic force with the higher order polynomials, (i.e., 2nd and 3rd order) in the denominator to best fit the experimental data. To stabilise the nonlinear EMLS in the larger operating range, the input-output feedback linearisation (IOFL)-based nonlinear controller is designed and implemented. Theorem 1, to guarantee the stability for the EMLS in the large region on the basis of quadratic Lyapunov function, is proposed. The investigations reveal that the proposed controller provides smooth and fast stabilising and tracking control response for different kind of trajectories. Under bounded vertical disturbances, (i.e., sinusoidal and random types), the proposed controller maintains the robustness.