Air Data Computation in Fly-by-Wire Flight-Control Systems

摘要

The aim of air data systems is the determination of flight parameters (such as pressure altitude, Mach number, angles of attack and sideslip) from measurements of local pressures and of local flow angles on wings or fuselage provided by a proper set of sensors. The active and integrated use of flight parameters in a full-authority fly-by-wire flight-control system imposes redundant system architecture to achieve an adequate level of reliability and safety. In this paper a methodology for air data computation is proposed that allows the flight parameters to be evaluated on the basis of data measured by four multifunction air data probes. It takes into account the effects of the modification of aircraft configuration during flight, as well as the effects of aircraft maneuver. Finally, it includes dedicated algorithms for the management of redundancy, which are able to detect possible system failures and to provide consolidated outputs. The methodology has been implemented in the Matlab/Simulink environment and a preliminary comparison of the results with flight test data showed satisfactory performance.