Integral Action for Chattering Reduction and Error Convergence in Sliding Mode Control

Sliding mode control is a standard approach to tackle the parametric and modeling uncertainities of a non-linear system. However, the robust control obtained by using sliding mode has a price, which is the high frequency chattering encountered during the digital implementation of the control. The idea of introducing a boundary layer around the switching surface and approximating a continuous control inside it has been extended for different kinds of systems. The systems should be analyzed to ascertain which continuous law is appropriate within the boundary layer. In this paper the effect of various continuous control approximations within the boundary layer to chattering and error convergence in different systems is studied