l2-l∞ filtering for multirate systems based on lifted models

For a multirate sample-data system where the output sampling rate is slower than the input updating rate, we study the l(2)-l(infinity) filtering problems for fast state estimation by using the lifted model. The filtering problem is handled in the framework of linear matrix inequalities (LMIs) with a nonconvex constraint, which is numerically solved by the product reduction algorithm. Finally, the effectiveness of the proposed method is illustrated and verified by simulation examples.