Estimation method of atmosphere angle of attack and angle of sideslip in high-angle-of-attack flight status

Abstract

The invention discloses an estimation method of an atmosphere angle of attack and an angle of sideslip in a high-angle-of-attack flight status. Under the premise that the structure of an aircraft is not changed and additional measuring devices and hardware devices are not added, the parameters output by the existing onboard strapdown inertial navigation system, a GPS (Global Position System) system, a flight control system and a fuel measuring system are fully used for resolving the angular acceleration, the rotational inertia, the product of inertia, the coefficient of a moment equation set and the total mass of the aircraft; based on a flight dynamics model, by establishing an extended Kalman filter, and integrating the processes of resolving the flight dynamics model and the status estimation together, accurate estimation of the current angle of attack, the angle of sideslip and the true airspeed is realized, and then the current air speed and the change rate of the air speed are resolved and input into the extended Kalman filter as the feedback information so as to finish the real-time accurate estimation of the angle of attack and the angle of sideslip of next time; the real-time accurate estimation of the angle of attack and the angle of sideslip is realized by a recursive resolving mode, measurement range and measurement precision of an atmosphere data system are improved, and adaptability to complex flight environment is also improved.

Description

technical field [0001] The invention relates to a method for estimating an atmospheric angle of attack and a sideslip angle under a high-angle-of-attack flight state, and belongs to the technical fields of atmospheric data, aircraft control, inertial navigation, GPS systems, and the like. Background technique [0002] Angle of attack and angle of sideslip are two important parameters of aircraft flight state and flight mechanics. Their accuracy and reliability are directly related to the normal operation and performance of aircraft control, navigation, engine and fire control systems. The main tactical performance requirements of modern high-performance fighters include super maneuverability, supersonic cruise, stealth, high information superiority, etc. High maneuvering flight means that the aircraft has the ability to fly at a large angle of attack. Flying at a large angle of attack causes the airflow on the surface of the aircraft to separate, and the aircraft is in a non...

AI Technical Summary

Problems solved by technology

In 1991, a paper "Development of a Pneumatic High-Angle-of-Attack Flush Airdata Sensing (HI-FADS) System" published by NASA in the United States proposed a pressure sensor array embedded in different positions on the front of the aircraft. An embedded air data system that measures the pressure distribution on the surface of the aircraft and calculates the atmospheric parameters from the pressure distribution. This method can realize the measurement of the angle of attack and the angle of sideslip in a flight environment with a large angle of attack; US Patent No. 7,564,539B2 in 2009 : "Optical Air Data Systems Methods", proposed an optical method that uses Rayleigh scattering and Mie scattering effects between laser and atmospheric molecules and aerosols, and calculates atmospheric parameters according to the intensity of backscattered signals and Doppler frequency shift This method is not affected by the flight state when measuring atmospheric parameters, and can meet the measurement of angle of attack and sideslip angle under the flight state of large angle of attack; the above two methods adopt the research of new embedded air data system and optical atmospheric data system. The method of data system is technically difficult and expensive; in 2006, AIAA published a paper "Flight Testing of the X-45AJ-UCAS Computational Alpha-Beta System" on the conference "AIAA Guidance, Navigation, and Control Conference and Exhibit" ” provides a method for estimating the angle of attack and sideslip angle by using the inertial navigation system, flight control system and air data system, so as to avoid the influence of the characteristics of the large angle of attack on the measurement of the flight angle of attack and sideslip angle, but Because this method does not consider the influence of the actual wind speed around the aircraft, there are systematic errors in the estimated angle of attack and sideslip angle

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