Switching fuzzy observers for periodic TS systems

This paper considers the design of observers for periodic Takagi-Sugeno fuzzy models. The observer employed is also a periodic one. To develop the design conditions, a switching Lyapunov function defined at the time instants when the subsystems switch is used. Using the developed conditions we are able to design observers for TS models where the local models or even the subsystems are unstable. The application of the conditions is illustrated on numerical examples.