Sliding Mode Control Design for Magnetic Levitation System

Abstract

This paper presents a control system design for a magnetic levitation system (Maglev) or MLS using sliding mode control (SMC). The MLS problem of levitating the object in the air will be solved using the controller. Inductors used in MLS make the system have nonlinear characteristics. Thus, a nonlinear controller is the most suitable control design for MLS. SMC is one of the nonlinear controllers with good robustness and can handle any model mismatch. Based on simulation results with a step as input reference, MLS provided good system performances: 0.0991s rise time, 0.1712s settling time, and 0.0159 overshoot. Moreover, a prominent tracking control for sine wave reference was also shown. Although the augmented system had a chattering effect on the control signal, the chattering control signal did not affect MLS performances.

Back-stepping control of a dual rotary input magnetic suspension system

“…Therefore, a new output variable (𝑦) is defined as given in Eq. 8 which will force 𝑥 2 to follow 𝑣. 𝑦 = 𝑥 2 − 𝑣 = 𝑥 2 + 𝜆 𝑥 1 (8) Next, differentiate y with time to determine the control law:…”

“…Although fuzzy logic or artificial neural network type controllers have been extensively used to control magnetic levitation systems, the design of such non-linear controllers requires the designer to have a significant experience on the system to be controlled and a training data collected from the system ([1]- [6]). Furthermore, it is seen that sliding mode control has been frequently used to control magnetic levitation systems in literature ( [7]- [8]). However, it is known that the chattering phenomena in the control signal can lead to an undesirable vibratory movement, especially in suspension systems.…”