A state observer for a class of nonlinear systems with multiple discrete and distributed time delays

This paper considers the state observer problem for a class of nonlinear systems, which present multiple noncommensurate time delays as well as distributed delay terms. The proposed algorithm is an extension of the observer for nonlinear delayless systems proposed in 1993 by Ciccarella, Dalla Mora and Germani. It is proved that a suitable gain can be easily chosen such that the observation error goes to zero exponentially, with arbitrarily fixed decay rate.