Research On The Estimation Technology Of Air Data Based On Virtual Air Data At High Angle Of Attack

Air data is an important set of flight parameters of an aircraft, the performance and operationaleffectiveness of an aircraft are heavily influenced by the measurement performance of the Air DataSystem (ADS) and its adaptability to the flight environment. Mainly aimed at the demand of newgeneration of aircraft, the air data estimation technology based on virtual air data at high angle ofattack is studied in this thesis, for the purpose of improving the accuracy and measurement range ofair data when new aircrafts fly at high angle of attack and high maneuverability. The thesis hasimportant theoretical significance and reference value to the development of ADS for new aircrafts.The effect on the air data measurement from high angle of attack fight is analyzed, and the airdata model based on flight dynamics model is studied. The Inertial Navigation System (INS) aidedADS compensation filter algorithm is designed to eliminate the measurement error of air data at highangle of attack and high maneuverability. Simulation results validate the feasibility and efficiency ofthe algorithm.Aiming at the failure situation of ADS at high angle of attack, the fault tolerant estimationalgorithm for air data based on the fusion of INS and flight control system at high angle of attack isstudied. State model and observation model of the fault-tolerant estimation algorithm are established.The extended kalman filter is used to the solving of flight dynamics model and the process of stateestimation. Based on the high angle of attack flight simulation data from the X-Plane system, themethod for the parameters identification of moment equation in the flight dynamics model is designed,the fault tolerant estimation algorithm is simulated and the simulation results demonstrate theeffectiveness.The air data estimation algorithm based on BP neural network at high angle of attack is designedin the thesis. The neural network is trained and tested with improved BP algorithm and flightsimulation data. The estimation algorithm can accurate estimate air data at high angle of attack byusing accessible airborne parameters, and enhance the measurement accuracy of air data at high angleof attack.A Virtual Air Data System (VADS) simulation platform is proposed, the structure of VADSsimulation platform is designed, the availability of X-Plane in the simulation is analyzed, the dataformat in the X-Plane network port is analyzed, and the availability of VADS simulation platform isverified through the study of flight data. The simulation platform play an important role in supporting the estimation technology of air data based on virtual air data at high angle of attack.