ON THE STABILITY OF NONLINEAR PLANTS THAT INCLUDE AN OBSERVER FOR THEIR FEEDBACK LINEARIZATION

The states of a plant are required to achieve exact linearization via state feedback and transformation. This calls for an observer when all the plant states are not directly accessible, then the linearizing fe edback law can be implemented with the observer estimates. We analyse this situation from a stability point of view, for a class of nonlinea r systems and a class of observers. Morever, we set a sufficient condi tion that makes possible the stabilization of the whole feedback syste m: the plant, the observer and the (linearizing) feedback law. From th is condition, which depends on the observer gains and the linear feedb ack gains, we find a region for these parameters where the stability o f the whole system is guaranteed.