Unbiased filtering for a class of neutral delay system

This paper considers a robust H_infin filtering problem for a class of neutral delay differential systems. The main purpose is to obtain a stable linear filter such that the filtering error system remains robustly stable within a pre-specific H_infin attenuation level or minimum H_infin attenuation level gamma. Under the unbiased conditions, the sufficient conditions of the stability and H_infin performance for filtering error system are stated. Compared to standard H_infin filtering approach (without the unbiased condition), the unbiased filtering approach simplifies the designing procedure, and the error system is internal stable, independent of the stability of the original system. The validity of proposed filter design algorithm has been checked through a numerical example.