Unified analysis methods for a fault tolerant redundant strapdown inertial measurement unit

The use of a redundant strapdown inertial measurement unit (RSDIMU) has been considered as a source of sensor information for future aircraft. It is pointed out that failure detection and isolation (FDI) should be accomplished at the sensor level to ensure the accurate transfer of information to elements of the integrated avionics system. The present investigation is concerned with the impact of the FDI algorithm on system reliability and vice versa. A description is given of a technique to identify and assess critical areas of reliability requirements for the RSDIMU. Attention is given to the development of an FDI algorithm to meet these requirements.