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.
