APPLICATIONS OF SLIDING MODE CONTROL

Abstract

The thesis covers Sliding Mode Control in all its aspects i.e. basic idea, mathematical modelling, its design features. The Sliding Mode Control is a technique to make any linear or non-linear system unaffected to parametric uncertainty and external disturbances. The main vantage of sliding mode Control are order gets reduces, perturbances rejection and insensitivity to parameter fluctuation. The scheme of chattering is also dealt. The soul of study rests with the sliding surface design for the system. Since there is no unique way of designing a sliding surface for non-linear system, a time varying sliding surface is designed such that its parameters are designed in linear and time varying way to cope with the nonlinearity of the system. We design a linear time varying surface such that system state is on sliding surface from the start of the motion without reaching phase which in turn increases the toughness of the system. The method which is proposed is then implemented on real time inverted pendulum and quadcopter system. Position control of the quadcopter system is one of the most fascinating and difficult for control engineering. The time varying sliding mode control is been proved of being capable of controlling the quadcopter in air. Finally we compare design methods against conventional linear sliding mode control through simulations. Simulation results have shown that the design method enhances system performance reduces settling time. The proposed method has confirmed more robustness to disturbance and parameter discrepancies compared to its counterpart.