The principle of motions separation in state observers under the action of disturbances

The paper deals with state observer design problem for a nonlinear system under the action of disturbances. Decomposition synthesis of the observer with corrective actions in the form of sat-functions is designed. This observer provides estimates for unmeasured variables of the state vector and external disturbances without entering their dynamic model. These algorithms are used in the control problem of induction motor with incomplete measurements and the action of external disturbance.