A Calculation Method of Atmospheric Parameters Based on Strapdown Inertial Navigation and Flight Control System

Abstract

The invention discloses an atmospheric parameter calculation method based on a strapdown inertial navigation and flight control system. Based on the definition of the angle of attack and the angle of sideslip, the mapping relationship of the true speed projection to the aircraft system is established, combined with the stable high-altitude atmospheric flow velocity Features, using inertial navigation information to obtain a one-step prediction model of atmospheric parameters, according to the aerodynamic model of the aircraft, establish the functional relationship between aerodynamic parameters and atmospheric parameters, and construct the mathematical relationship between inertial navigation measurement values ​​and atmospheric parameters, through the extended Kalman filter method Solve for atmospheric parameters. This method provides redundant means for the measurement of atmospheric parameters, overcomes the difficulty of measuring atmospheric parameters at hypersonic speeds and large maneuvers, and can provide real-time atmospheric parameters within the flight envelope.

Description

technical field [0001] The invention relates to an atmospheric parameter calculation method, including the calculation of the angle of attack, the sideslip angle and the true airspeed, in particular to an atmospheric parameter calculation method based on a strapdown inertial navigation and flight control system. Background technique [0002] Atmospheric data system is an important airborne avionics equipment that completes the perception, measurement, calculation and output of atmospheric parameters. At present, there are mainly two types of traditional atmospheric data systems and embedded atmospheric data systems. [0003] The traditional air data system is marked by the pitot tube extending out of the body, and combined with other sensors (angle of attack / sideslip angle / total temperature sensor) to achieve direct measurement of total pressure, static pressure, angle of attack, sideslip angle and total temperature , and then use the atmospheric data computer to perform rel...

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Problems solved by technology

[0007] Purpose of the invention: In order to overcome the problem of difficult measurement of atmospheric parameters under hypersonic speed and large maneuvering conditions in the prior art, provide real-time atmospheric parameters within the flight envelope, and provide a redundant means of atmospheric parameter measurement that does not require additional hardware equipment; the The method is applicable to the strapdown inertial navigation / flight control system. Based on the definition of the angle of attack and sideslip angle, the mapping relationship between the true airspeed projection and the aircraft system is established. Combining with the characteristics of stable high-altitude atmospheric flow velocity, the inertial navigation information is used to obtain the atmospheric parameters. One-step prediction model, according to the aerodynamic model of the aircraft, establish the functional relationship between the aerodynamic parameters and the atmospheric parameters, build the mathematical relationship between the inertial navigation measurement value and the atmospheric parameters, and solve the atmospheric parameters by the extended Kalman filter method, avoiding the The direct measurement of parameters solves the problem of measuring atmospheric parameters at hypersonic speeds and large maneuvers

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