This paper focuses mainly on the classical variable structure control (VSC), also known as sliding mode control (SMC) theory briefly In section1.2.the paper introduces the classical principle of sliding mode control method. Standard sliding modes provide for finite-time convergence, precise keeping of the constraint and robustness with respect to internal and external disturbances are explained by example.1.However, often they also exhibit a serious drawback which essentially hinders their practical applications. This drawback is high frequency oscillations which inevitably appear in any real system is usually called chattering. This is a highly undesirable phenomenon, because it causes serious wear and tear on the actuator components. Therefore, two methods to eliminate chattering have been proposed in this paper. In section 3.1, Boundary Layer method is proposed and explained. In section 3.2 Asymptotic Sliding Mode approach is proposed and explained with example. 2. Conclusions are stated and further work on chattering elimination are listed

variable structure control, Sliding mode control, constraint, robustness, chattering, Boundary Layer;