Simplified robust fuzzy output regulator design for discrete-time nonlinear systems

摘要

This paper proposes the simplified robust T-S fuzzy output regulator for discrete-time affine nonlinear systems in the presence of parametric uncertainties and external disturbance. First, a virtual desired variable (VDV) based fuzzy output regulator is developed by involving integral compensation and virtual desired state profile. Meanwhile, the sufficient condition of asymptotic output regulation is formulated in LMIs. Since the VDV-based fuzzy regulator is unavailable for the system corrupted by parametric uncertainty and external disturbance, we further modify the above one to a simplified non-VDV fuzzy output regulator which only consists of an integral-type PDC controller without VDV calculation. The asymptotic output regulation is achieved for the uncertain system without disturbance. Afterward, the robustness is enhanced to satisfy an H-infinity criterion for attenuating the effect of disturbance and modelling error via robust LMI-based gain design. Compared with traditional methods, the proposed fuzzy controller is more simplified and robust without using error coordinate transformation and solving regulation equations. Finally, a truck-trailer system is taken as applications to show expected control performance.