Atmospheric parameter calculation method 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 definition of an attack angle and a sideslip angle, a mapping relation of true air speed projection to a machine system is established. Combined with a characteristic of stable high-altitude atmosphere flow speed and by utilization of inertial navigation information, a one-step prediction model of the atmosphere parameter is obtained. According to an aircraft pneumatic model, a function relation of a pneumatic parameter and the atmosphere parameter is established, a mathematical relation of an inertial navigation measuring valve and the atmosphere parameter is constructed, and the atmosphere parameter is solved through a Kalman filtering expansion method. The method provides a redundant means for measurement of the atmosphere parameter, solves measuring problems in hypersonic speed and high maneuver conditions and can provide an atmosphere parameter in real time in a flight envelope.

Description

technical field [0001] The invention relates to an atmospheric parameter calculation method, including the calculation of attack angle, sideslip angle and true air speed, 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 device that completes the perception, measurement, calculation and output of atmospheric parameters. At present, there are mainly two types: traditional atmospheric data system and embedded atmospheric data system. [0003] The traditional air data system is marked by the pitot tube protruding from the airframe, 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 relevant calculations and...

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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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