On virtual observers in fault tolerant control

An approach to the virtual observers design, adjusted for linear continuous-time systems, is proposed in the paper. Using the H∞ principle, new conditions for the virtual actuator design are formulated in terms of linear matrix inequalities and, in addition, the same method is used to reformulate the conditions for the virtual sensors, as well as for the static output control synthesis. Related to the static output control structure under influence of sensor and actuator faults, a numerical example is presented to highlight the benefit of the proposed framework.