关键词: 故障检测, 滤波器滤波, 线性矩阵不等式

Abstract: The robust fault detection filter（RFDF） design problem for linear time invariant（LTI） system with unknown inputs is studied.Consider that the fault signals usually lie in a finite frequency range，the design objective is set to minimize the combined performance index over the specified frequency range as well as to satisfy regional constraint on filter poles.A linear matrix inequality（LMI） based solution is proposed.The advantages of the proposed solution lie in that the real values of the indices over the given frequency range are accessible during the solving process and the optimal solution can be achieved.Therefore，the designed RFDF can acquire a satisfactory performance.An aircraft design example demonstrates the effectiveness of the solution.

Key words: fault detection, filter design, linear matrix inequality（LMI）