Generalized Likelihood Test for FDI in Redundant Sensor Configurations

The Generalized Likelihood Test (GLT) approach to failure detection and isolation (FDI) in redundant sets of inertial sensors is described and its relationship to the overall FDI structure is explored. Specific formulations of both the detection and the isolation problems are presented. The performance of the resulting FDI system is analyzed by means of the second-order statistics of the detection and isolation decision functions. The equivalence of the GLT approach to several previously reported approaches for both single-degree-of-freedom (SDOF) and two-degree-of-freedom (TDOF) sensors is described. To illustrate its application, the GLT approach is used to compare the FDI performance of three different redundant sensor configurations; a conical configuration of five SDOF sensors, a dodecahedron configuration of six SDOF sensors, and an octahedron configuration of four TDOF sensors.