State and Disturbance Observer based Sliding Mode Control for Nonlinear Uncertain Mismatched Systems

The control design for general nonlinear uncertain mismatched systems is challenging when all the states are not available and the available states are affected by measurement noise. In this paper, a novel state and disturbance observer based sliding mode control design for nonlinear uncertain mismatched system is proposed. The proposed control strategy does not require the measurement of all the states of the mismatched system and at the same time it ensures that the tracking accuracy is better than the conventional results as well as latest result in [1]. The proposed method makes the approaches in [1], [12] implementable for the applications where all the states are available for the control design. The paper further analyses the effect of measurement noise on the output tracking accuracy. The comparative study is carried out to prove the effectiveness of the proposed controller.