System for estimating airspeed of an aircraft based on a drag model

Abstract

A system and method for estimating a plurality of airspeed parameters of an aircraft is disclosed. The system comprises one or more processors and a memory coupled to the processor. The memory storingdata comprises a database and program code that, when executed by the one or more processors, causes the system to receive a plurality of operating parameters that each represent an operating condition of the aircraft. The system is further caused to determine a stability-axis drag coefficient based on the plurality of operating parameters. The stability-axis drag coefficient quantifies a stability-axis drag of the aircraft created during high speed conditions. The system is caused to determine a body-axis lift coefficient based on the plurality of operating parameters, which corresponds to alift of the aircraft created along a vertical body-axis. The system is also caused to determine a dynamic pressure, which is used to estimate the airspeed parameters.

Description

Background technique [0001] The disclosed systems and methods relate to systems for estimating the airspeed of an aircraft, and more particularly to systems including a model for estimating airspeed, especially in high speed regimes of the aircraft. [0002] Pitot tubes or probes are typically mounted on the vehicle and measure the velocity of the vehicle relative to the fluid in which the vehicle is moving. In one application, a Pitot probe is mounted on an aircraft and measures the velocity of the aircraft relative to the mass of air during flight. Pitot tube probes typically include a hollow tube defining an open end pointing in the direction of fluid flow or vehicle motion. The hollow tube of the pitot probe contains a fluid, such as air in the case of an aircraft. The pressure inside the pitot tube provides a stagnation pressure measurement (also known as total pressure). This total pressure is combined with the static pressure, which is usually measured at various loc...

AI Technical Summary

Problems solved by technology

Systems exist to estimate airspeed based on a model of the aircraft, however these systems may not be robust to calculating accurate airspeed under certain types of operating conditions

more specifically, these systems may not be able to calculate accurate airspeed during high-speed flight regimes, especially at transonic Mach numbers

Also, the airspeed calculated by the system may be susceptible to changes in the aircraft's sensed angle of attack

Finally, even where accurate airspeed calculations are possible, airspeed may be susceptible to any differences in the lift model

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