关键词: 自动控制技术, 时滞系统, 无偏条件, H∞滤波, Lyapunov函数, 线性矩阵不等式

Abstract: A linear matrix inequality (LMI) approach was used to design an unbised H∞ filter and the estimation for state variables which were not easily measured in the time delay system was conducted. This filtering error system derived on the basis of LMI satisfiies asymptotically stable condition and H_∞ norm of the transfer function of the error system is less than a possitive scalar γ. By the introduction of the unbiased condition, the the proposed approach overcomes the stability limitation in the estimation of the time dealy system, and it can be applied in the estimation of unobservable states of either critical stable and unstable time delay systems. In addition, this approach was used in the estimation of the composition of the product P with a single time delay system in the oil refinery process. In comparison to the filtering approach without delay information, the estimation error of the proposed method is smaller.

Key words: automatic control technology, delay system, unbiased condition, H∞ filter, Lyapunov function, LMI