Error Analysis Of Flush Air Data Sensing System&Research On Methods Of Error Eliminating

The flush air data sensing (FADS) system uses pressures of ports arranged on plane surface to inferair data we need. Historically, the traditional air data sensing system affects aerodynamics and stealthperformances of fighters, but the flush type can avoid these problems and it is more precise, reliableand maintainable. It is a new way to sense air data. The good performances attract many aerospacespecialists to research it. In order to know the precision of FADS system, error analysis is necessary.This paper focuses on error analysis of FADS system and error eliminating.There are many types of errors in FADS system using. This paper analyses pneumatic lag error,viscous interaction error, thermal transpiration error, initial port misalignment error, structuraldeformation caused by thermal expansion, sensor transduction error, sensor measurement error andsensor delay error, models them, and does simulation to see how seriously they affect FADS systemprecision.In order to solve the problem that static ports pressure data can’t be used to do delay errorssimulation, and to find a better way to do error analysis, Monte Carlo Method is used to do FADSsystem simulation to analyze errors along flight path. Then, compare simulation results with flightpath data, error data can be obtained, and RMS error can be calculated. In this way, FADS systemweak points can be showed, its precision can be known better. Changing FADS algorithm, this methodcan be used to compare different algorithms, providing some reference to select FADS algorithm.At the last part of this paper, methods of error elimination are discussed including systematiccorrection and FADS/INS combination method. Both INS/the Triples and INS/table lookupcombination methods are introduced and simulated. The results show that FADS/INS combinationmethod can eliminate various errors and improve FADS system precision.