Optimization of the High Angle of Attack Flush Air Data Sensing (HI-FADS) System Algorithm Executed in Real-Time on Multi-Processor Transputer Networks

David K. Taniguchi

Abstract:	Air data is typically gathered by conventional measuring devices such as pitot-static pressure probes and angle of attack vanes that protrude from the aircraft surface. However, in many modem aircraft applications the use of conventional, intrusive air data systems may be inappropriate. An experimental non-intrusive flush port air data collection system has been developed and installed on the High Angle of Attack Research Vehicle (HARV) at the NASA Ames-Dryden Flight Research Facility. This research has investigated the use of an array of pressure measuring orifices located flush to the surface of the aircraft’s nose cap to derive operational air data parameters. Post-flight processing of recorded flight test data with the High Angle of Attack Flush Air Data Sensing (HI-FADS) System algorithm has established system accuracy and repeatability. This paper describes the evaluation of the processing requirements for the HI-FADS algorithm as related to potential real-time, airborne applications. Concurrent algorithm execution was studied on multi-processor systems of various configurations with networks of transputers. The transputer, manufactured by Inmos, is a microcomputer on a chip incorporating four serial data links that offer point-to-point communication. Therefore, by connecting links between transputers, multi-processor networks of selected configuration and size were developed. With consideration to system design constraints and algorithm structure, computing throughput and latency were optimized for each network and then related to the performance characteristics of single transputer execution. In addition, the effect of increased algorithm complexity on relative performance was investigated. A simple, but computationally intensive Pressure Port Fault Management process was developed and incorporated into the HI-FADS algorithm. The optimized multipletransputer relative performance characteristics of this algorithm and the original, unmodified HI-FADS algorithm were then compared. These results are also discussed.
Published in:	Proceedings of the 46th Annual Meeting of The Institute of Navigation (1990) June 26 - 28, 1990 Atlantic City, NJ
Pages:	157 - 164
Cite this article:	Taniguchi, David K., "Optimization of the High Angle of Attack Flush Air Data Sensing (HI-FADS) System Algorithm Executed in Real-Time on Multi-Processor Transputer Networks," Proceedings of the 46th Annual Meeting of The Institute of Navigation (1990), Atlantic City, NJ, June 1990, pp. 157-164.
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