Abstract: Abstract：The fault diagnosability analysis method of the liquidfloated gyro based on the dependency model is proposed to enhance its fault diagnosis performance. Considering the relationship of the functional modules in the liquidfloated gyro, we obtain the information flow model firstly. And then the relative matrix between the faults and sensors is given according to the FMEA results. Based on the relative matrix, the fault detectability and isolability analysis process and sensor selection and optimization are addressed. Because the relative model belongs to the qualitative model, the presented fault diagnosability analysis method is easy to establish and compute. Our method not only evaluates the diagnosability design of the liquidfloated gyro but also offers some important information for optimization of sensor allocation. Keywords：dependency model; fault diagnosability design; sensor placement optimization; liquidfloated gyro

Key words: dependency model, fault diagnosability design, sensor placement optimization, liquidfloated gyro