Accession Number : ADA045671


Title :   Fault Tolerant Digital Flight Control with Analytical Redundancy.


Descriptive Note : Final rept. 1 Jan 76-1 Feb 77,


Corporate Author : HONEYWELL INC MINNEAPOLIS MINN SYSTEMS AND RESEARCH CENTER


Personal Author(s) : Cunningham,Tom ; Carlson,Don ; Hendrick,Russ ; Shaner,Don ; Hartmann,Gary


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a045671.pdf


Report Date : May 1977


Pagination or Media Count : 396


Abstract : Analytical redundancy offers high potential for solving the sensor redundancy problem. The current state-of-the-art in analytical redundancy contains a number of candidate filters which are developed here from a fundamental relationship of variables through hybrid simulation. Three analytical redundancy concepts of varying complexity were developed for the A-7D aircraft. Two monitor techniques were used: a multiple trip level exceedance criteria currently in use with voting systems, and a sequential likelihood ratio hypothesis test (SLRT) on the mean value of the error signal. Results indicate that fault detection, whether designed by classical methods or Kalman filtering, perform similarly and that gust estimation improves fault detection performance. Also, failure isolation for a single set of unlike sensors is difficult to achieve with a reasonable computation load. The output recommendation is to proceed to flight test with a set of nonlinear diagnostic filters to be used with comparison monitors for dual sensor failure isolation, creating a fail-operative dual sensor system. Fail-safe operation will also be achieved by continuing to monitor the filters and to detect, but not isolate, a second failure. (Author)


Descriptors :   *REDUNDANCY , *FAULT TOLERANT COMPUTING , *FLY BY WIRE CONTROL , ALGORITHMS , DIGITAL SYSTEMS , DETECTORS , MONITORING , FAILURE , KALMAN FILTERING , ESTIMATES , RELIABILITY , ERROR ANALYSIS , GUSTS , ATTACK AIRCRAFT , DIAGNOSTIC EQUIPMENT , FAULTS , FAIL SAFE , HYBRID SIMULATION


Subject Categories : Attack and Fighter Aircraft
      Mfg & Industrial Eng & Control of Product Sys


Distribution Statement : APPROVED FOR PUBLIC RELEASE