Reduced-order observers for nonlinear sampled-data strict-feedback systems with control input update delay

Design of reduced-order observers is considered for nonlinear sampled-data strict-feedback systems with control input update delay. On the basis of the Euler-like approximate model, reduced-order observers are designed. Then the relationship between the magnitude of control input update delay and that of estimation errors is discussed. A numerical example is also given to illustrate the theory.