Intelligent FDI management in the adaptive tactical navigator

The authors examine the use of a failure detection and identification (FDI) method in the adaptive tactical navigator (ATN) as a means for monitoring the health of navigation-aiding equipment. The objective of FDI is to detect sensor failures before the problem worsens to the point of requiring pilot intervention. The method uses parity functions to compare dissimilar measurements, and thus utilize the inherent analytical redundancy of measurements in multisensor navigation systems. Preliminary simulation results are presented to demonstrate the workings of the FDI method. It is concluded that the use of sets of parity functions, derived from different sensor combinations, holds promise as a device for the identification of sensor failures. The simulation example suggests that the method can detect and identify simple failures in a reasonably short time (under a minute)