Robust fuzzy control with sliding mode property and inherent boundary layer

A new sliding mode fuzzy controller (SMFC) with smooth control law is proposed for a class of nonlinear system with a known linear model. The concept of variable structure system with sliding mode is employed to derive a set of rules for a robust fuzzy controller. The proposed controller preserves the most fundamental property of conventional sliding mode control (SMC) that is robustness, invariance to parameters variations, and model uncertainties. However, unlike the conventional sliding mode control, SMFC eliminates the chattering problem through the concept input-output mapping factor and behave like a linear controller in the neighborhood of its sliding manifold. To illustrate the performance of SFMC, we applied it to the inverted pendulum problem on a cart. Simulation studies were conducted on stabilizing the inverted pendulum to its upright position from various initial conditions in the presence of external disturbances, model uncertainties, and parameters variation.