Output regulation of discrete-time nonlinear systems based on T-S fuzzy model

The output regulation problem is discussed for a class of discrete-time nonlinear systems under periodic disturbances generated form the so-called exosystems. The system is represented by T-S fuzzy model. With the assumption that the subsystem in each fuzzy rule is of the controllable canonical form, the regulation equations are solvable if and only if the poles of the exosystem are different from those of the fuzzy system. By exploiting the structural information encoded in the fuzzy rules, a piecewise state-feedback and a piecewise error-feedback control laws are constructed to achieve asymptotic rejecting of the unwanted disturbances and/or tracking of the desired trajectories.