Accession Number : ADA189864

Title :   N-Version Software Demonstration for Digital Flight Controls.

Descriptive Note : Final rept.,

Corporate Author : LOCKHEED-GEORGIA CO MARIETTA

Personal Author(s) : Mulcare, Dennis B ; Barton, Lynn A

PDF Url : ADA189864

Report Date : Apr 1987

Pagination or Media Count : 152

Abstract : This report illustrates how four independently developed versions of digital flight controls applications software might be used in quadruplex system architecture. This approach to software fault tolerance is called N-version software. Here each computer channel has distinct versions of Ada programming units performing the same functions concurrently. Since intermediate software results are voted to detect and isolate discrepant computations, cross-channel synchronization occurs at each voting plane. The demonstration of this system was based on a high-level software design, English language specifications, and associated Ada program unit specifications parts. The demonstration was performed in non-realtime on a single VAX 8600 computer using an Ada multitasking test harness to effect voting plane synchronization and test case application and analyses. Keywords include: Ada Programming Language, Digital flight controls, Multitasking Test harness, N-Version programming, Quadruplex redundancy, Software fault tolerance, Software specification, and Software testing .

Descriptors :   *FLIGHT CONTROL SYSTEMS, ARCHITECTURE, COMPUTATIONS, COMPUTER PROGRAMS, COMPUTERS, DIGITAL SYSTEMS, ENGLISH LANGUAGE, FAULTS, PROGRAMMING LANGUAGES, REDUNDANCY, SPECIFICATIONS, TEST AND EVALUATION, TOLERANCE, FAULT TOLERANT COMPUTING

Subject Categories : Flight Control and Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE