Improved robust H∞ filtering for uncertain discrete-time switched systems

This paper is concerned with the robust H_infin filtering problem for uncertain switched linear discrete-time systems. Combining the mode-switching idea with the well-known Finsler´s lemma, and further utilising the parameter-dependent result, a new characterisation of the asymptotic stability with an H_infin noise-attenuation level bound for the filtering error system has been addressed. The existence condition of such a filter is formulated in terms of dilated linear matrix inequalities. This directly leads to performance improvement and reduction of conservativeness in the filtering solution. Performance of the presented approach in comparison with that of the existing results is illustrated by a numerical example.