Nonlinear large disturbance attenuation controller design based on backstepping method

In this paper, a novel robust nonlinear control strategy based on backstepping technology is investigated for a class of strongly nonlinear control problem via. The advantage of the proposed method lies on the use of the minimax optimal control theory during classical backstepping design procedure. Focus is given on the effect of unknown disturbances on the output of the system. Existing treatment of the disturbances is often characterized by conservativeness in the estimation of the upper bound of the disturbance or inequality scaling. While this paper applies the minimax method to estimate the highest degree of critical disturbance that can be endured by the system, which reduces effectively the conservativeness and ensures good robustness. Simulation results demonstrate the effectiveness of the proposed control methodology.