Title

Fault Tolerant Digital Flight Control with Analytical Redundancy

Date

1977

Identifier

ADA045671

ADA045671

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.

Date Issued

1977-05

Extent

396

Corporate Author

Honeywell Systems & Research Center

Laboratory

Air Force Flight Dynamics Laboratory

Report Number

AFFDL-TR-77-25

Contract

F33615-76-C-3031

DoD Project

1987

DoD Task

198701

Distribution Conflict

No

Access Rights

Approved for public release; distribution unlimited

Photo Quality

Incomplete

Distribution Classification

1

DTIC Record Exists

Yes

Report Availability

Full text available by request

Creator

Cunningham, Tom

Carlson, Don

Hendrick, Russ

Shaner, Don

Hartmann, Gary

Stein, Gunter

Provenance

University of Colorado Colorado Springs, Kraemer Family Library

Type

report