No abstract

International audienceThis work presents a simple observer for triangular nonlinear systems with time varying delayed output measurement. A sufficient condition ensuring the asymptotic convergence of the observation error towards zero is given, as well as an explicit relation between the bound of the delay and the parameter of the observer. This result is illustrated by some simulations

Abstract-This brief presents an adaptive variable structure identifier that provides finite time convergent estimate of the induction motor rotor resistance under feasible persistent of excitation condition. The proposed rotor resistance scheme is based on the standard dynamic model of induction motor expressed in a fixed reference frame attached to the stator. The available variables are the rotor speed, the stator currents and voltages. Experiments show that the proposed method achieved very good estimation of the rotor resistance which is subjected to online large variation during operation of the induction motor. Also, the proposed online simplified rotor resistance estimator is robust with respect to the variation of the stator resistance, measurement noise, modeling errors, discretization effects and parameter uncertainties. Important advantages of the proposed algorithm include that it is an online method (the value of can be continuously updated) and it is very simple to implement in real-time (this feature distinguishes the proposed identifier from the known ones).Index Terms-Equivalent injection term, nonlinear observer, online parameter estimation.

No abstract

No abstract

No abstract

In the literature, it has been noted that, if an analytic nonlinear plant has (1) a well-de ned relative degree and is (2) minimum-phase, it is possible to achieve asymptotic tracking for an open set of output trajectories containing the origin in C N m 0; 1), the space of N-times continuously di erentable functions taking values in IR m. When either of these su cient conditions is not met, various authors have investigated approximate analytic solutions, discontinuous solutions and solutions for restricted sets of trajectories. In this paper, it is shown that conditions (1) and (2) are necessary for the existence of an analytic compensator which yields asymptotic tracking for an open set of output trajectories.

No abstract