DOB Tracking Control for Systems with Input Saturation and Exogenous Disturbances via T-S Disturbance Modelling

In this paper, the anti-disturbance dynamical tracking problem is investigated for a class of systems subject to input saturation and unknown disturbances under the framework of disturbance-observer-based-control (DOBC). In order to expand the application scope of exogenous disturbances, T-S fuzzy models are employed to describe those complex nonlinear disturbances, and the corresponding disturbance observer is also well designed. The PI-type composite controller with the estimates of disturbance is designed to ensure the system stability and the convergence of tracking error to zero. Meanwhile, an estimation of domain of attraction can also be described by the level set of the Lyapunov function. Finally, a simulation example for flight control systems with nonlinear disturbances is given to verify the effectiveness of the proposed schemes.