Control of MagLev System using Supertwisting and Integral Backstepping Sliding Mode Algorithm

Abstract

Magnetic Levitation technology is used in various fields of every day life e.g. MagLev trains, bearing-less motors, MagLev heart, launching pads, levitation of heavy metals etc. As these systems are nonlinear in nature and prone to external disturbances, there fore a suitable nonlinear controller is needed that can improves the dynamic response and is robust against external disturbances. Also chattering phenomenon is an issue for robust controllers and an undesirable characteristic as it proves to be harmful for real systems. In this thesis, First a simple nonlinear model of the MagLev system (contain ing an iron ball as a magnetic material) is designed using the fundamental Kirchoff’s Laws. In the subsequent sections, two nonlinear controllers based on Supertwisting and Integral Backstepping sliding mode algorithms are designed to control the nonlinear model. The designed controllers ensure the desired air gap to be preserved while simul taneously tracking the momentum and magnetic flux of the system to their respective reference values. External disturbances are added in the system to check the perfor mance of the controllers in terms of robustness. Lyapunov theory is used to prove the global asymptotic stability of the system.To validate the performance, simulations are performed using MATLAB environment. Comparison of the designed controllers with each other and also with the already published nonlinear controllers shows the supe riority of supertwisting based controller in terms of dynamic response, elimination of chattering, and robustness against external disturbances.