High gain observer-based fault estimation for nonlinear networked control systems

In this paper, an observer-based fault estimation (FE) method is presented for a class of nonlinear networked control systems (NCSs) with Markov transfer delays. First, the nonlinear NCSs are modelled by nonlinear discrete Takagi-Sugeno (T-S) fuzzy model with modelling uncertainty. Under some geometric conditions, the proposed nonlinear T-S model can be transformed into two subsystems with one of them having backstepping form. Then, the discrete nonlinear observer is designed to provide the estimation of unmeasurable state and the modelling uncertainty, which is used to construct a fault estimation algorithm. Finally, an example is included to show the efficiency of the proposed method.