Abstract
The problem of adaptive robust state observer design is considered for a class of nonlinear dynamical systems with significant uncertainties. It is supposed that the upper bound of the nonlinearity and uncertainty is a linear function of some parameters which are still assumed to be unknown. An improved adaptation law with σ-modification is employed to estimate the unknown parameters. Then, by making use of the updated values of these unknown parameters a class of adaptive robust state observers is proposed for uncertain dynamical systems. It is also shown that by employing the proposed adaptive robust state observer, the observation error between the observer state estimate and the true state can converge asymptotically to zero in the presence of significant uncertainties. Finally, a numerical example is given to demonstrate the validity of the results.
