A method for searching and evaluating diagnosable sequence fault sets of a dependency matrix

Based on the single-fault diagnosis theory and the evaluation requirements of residual diagnosis information in a dependency matrix, a new method for searching and evaluating diagnosable sequence fault sets of a dependency matrix is proposed. Definitions of diagnosable sequence fault set and dependency sub-matrix are given. The generation algorithm of a dependency sub-matrix which is based on original faults is studied, with the exit condition of this generation algorithm established. Based on the dependency sub-matrix, the searching flow of full diagnosable sequence fault sets is given, and the parameters of residual diagnosis information evaluation for the sets are determined. These parameters include maximum depth, minimum depth, average depth and fault unique isolation percentage. A case of an avionic subsystem with a dependency matrix is given, and the above method is applied. The result shows that all diagnosable sequence fault sets of a dependency matrix can be found, and this method can be used to evaluate the residual diagnosis information in a dependency matrix.