International audienceThe observation of a class of multi-input multi-output (MIMO) state affine systems with both sampled and delayed output measurements is addressed. These two constraints disturb simultaneously the convergence of the observer. Assuming some persistent excitation conditions to hold, and by using Lyapunov tools adapted to impulsive systems, two classes of global exponential observers are proposed. Some explicit relations between maximum allowable delay and maximum allowable sampling period are given. An extension to some classes of nonlinear systems is also given

The synthesis of a high gain observer for the on-line estimation of the rotor fluxes, the motor speed and the load torque of the induction motor from the current and voltage measurements is presented. The synthesis of the observer is preceded by an observability analysis of the induction motor leading thereby to a sufficient condition. The obtained condition is discussed and it is shown that it is generally satisfied in practice when considering the usual operating conditions of the motor. Of particular interest, an implementation procedure is proposed to deal with the observation singularities. The proposed observer has been validated in simulation using the reference trajectories of a realistic proposed benchmark where the induction motor model remains in an unobservable region and not just go across.