Abstract: The correlation matrix of gyros is built firstly based on analysis of gyro’s fault model and the correlation between different gyro modules. Then a preliminary result of gyro model diagnosis is obtained using the detectability and separability theorems. Then the ambiguity group of correlation matrix is separated further via improved BHStree. Finally the diagnosability is evaluated by the proposed method. Some suggestions are presented to improve the diagnosability. Moreover, some approaches are given to resolve the key problems in programming for diagnosability analysis and validation.

Key words: multisignal flow graph, improved BHStree, diagnosability, detectability, separability