Adaptive Higher Order Sliding Mode Control for Nonlinear Uncertain Systems

Abstract Sliding mode control (SMC) is used for the control of uncertain systems with known uncertainty bounds. But most of the times, the uncertainty bounds are not known. Adaptive SMC (ASMC) is used in these cases for the control of unknown but bounded systems. But ASMC, like the conventional SMC, suffers from chattering. To overcome this drawback, we have proposed an improved control algorithm which uses the concept of adaptive higher-order SMC (AHOSMC). In the proposed algorithm, we have designed the first derivative of the control taking it as the virtual control rather than the actual control itself. The gain-adaptation law does not overestimate uncertainties. The proposed technique has been validated using simulation results.