Observer-based backstepping control for nonlinear cyber-physical systems with incomplete measurements

This paper investigates the problem of observer-based control for cyber-physical systems (CPSs) with incomplete measurements. The CPSs are described as a class of nonlinear strict-feedback systems. When data transmission problems, such as information packet losing or transmission medium saturation, occur, the state variables become unavailable or distorted. To solve these problems, two-state estimators are constructed for different transmission cases, based on which two backstepping controllers are designed. The stability conditions of the state estimators and closed-loop system are derived by solving a linear matrix inequality (LMI). It is proved that the control methods can guarantee that all the signals of the closed-loop system are uniformly ultimately bounded (UUB) in mean square. The effectiveness of the proposed methods is confirmed by a simulation example.