A threshold redundancy management algorithm for skewed sensor arrays

A thresholdless algorithm for redundancy management that can be used to obtain specified failure tolerance for a given SRIMU (skewed redundant inertial measurement unit) is presented. The algorithm is an extension of some earlier work by J.E. Potter and M.C. Suman (1986), which presented a method for implementing threshold less (FDI) (fault detection and isolation) on a pentad skewed sensor array. The proposed algorithm overcomes the single-failure-tolerance restriction of Potter´s algorithm, and allows thresholdless FDI to be practically implemented on a hexad or higher order array. Some performance results are given which compare a hexad IMU, under a particular failure scenario, with no FDI algorithm, a threshold FDI algorithm, and the thresholdless FDI algorithm. The performance of the thresholdless FDI algorithm is seen to be comparable to that of the threshold FDI algorithm for the particular launch vehicle trajectory. Thus, comparable performance to threshold FDI algorithms may be attained by the thresholdless algorithm without the additional complexity of threshold determination