Output regulation control for MIMO nonlinear system with mismatched disturbances and its application to BTT missiles

In this paper, output regulation control problem is developed for a class of multi-input and multi-output (MIMO) nonlinear system with mismatched disturbances. A composite control scheme is proposed via backstepping method and nonlinear disturbance observer technique. In order to reject the mismatched disturbances, a novel idea is that disturbance estimation is introduced into virtual control laws at each step. Stability analysis is achieved by Lyapunov function theory. It is shown that the system output asymptotically converges to zero in the presence of mismatched disturbances. A bank-to-turn missiles application demonstrates the effectiveness of the proposed method finally.