A Method for Determining Air Pressure Altitude Parameters on Subsonic Aircraft Body

Abstract

The invention discloses a determination method for pressure altitude parameters on a subsonic vehicle body. The determination method comprises a selection principle of a pressure source on the subsonic vehicle body and a data processing method for measuring pressure based on a selected pressure source, wherein the selection principle of the pressure source on the subsonic vehicle body is used for selecting and locating the pressure source; the data processing method for measuring pressure based on the selected pressure source comprises a correction formula fitting and measured value returning and calculating method, wherein the correction formula comprises [alpha] correction, [beta] correction and static pressure correction, and the returning and calculating method is a method that objective variables are obtained according to the iteration of pressure measuring values. Test results show that the corrected data has very high reducibility, the objective variables including a flying attitude angle, a speed and the like of a subsonic vehicle with higher precision can be obtained by combining the returning and calculating method, therefore, a new method is provided for the subsonic flying speed measurement of the subsonic vehicle.

Description

technical field [0001] The invention relates to a method for determining air pressure altitude parameters on a subsonic aircraft, which is used for real-time calculation of part of the flight state parameters of the aircraft and provided for use by a flight control system. Background technique [0002] Any aircraft is required to fly at a certain speed, altitude and attitude angle, so it is of great significance to determine the flight state in time for the aircraft. The most conventional method for determining the flight state (subsonic speed) is to measure the static pressure, total pressure and attitude angle sensing pressure (or wind vane). The pitot tube is used to measure the total pressure and static pressure of the incoming flow, and the isentropic flow relation The flight speed can be determined, and the flight altitude can be determined by using the static pressure. The attitude angle can be calculated by using the sensory pressure correction formula (or wind scale...

AI Technical Summary

Problems solved by technology

The most conventional method for determining the flight state (subsonic speed) is to measure the static pressure, total pressure and attitude angle sensing pressure (or wind vane). The pitot tube is used to measure the total pressure and static pressure of the incoming flow, and the isentropic flow relation The flight speed can be determined, and the flight altitude can be determined by using the static pressure. The attitude angle can be calculated by using the sensory pressure correction formula (or wind scale). It is very long, which is not good for the design of modern aircraft, especially those that emphasize stealth performance

The aerodynamic compensation pitot is developed on the basis of the conventional pitot. The length and size of the aerodynamic compensation pitot are greatly reduced compared with the conventional pitot, but the degree of influence by other parts of the aircraft is correspondingly increased. In order to To eliminate the influence of various components at subsonic speeds, special curve processing is required to compensate the shape of the pitot tube. The most important thing is to compensate the measured pressure in a specific state during measurement to make it closer to the real static pressure. To do this, it is necessary to determine in advance the variation of pressure with the flight state and find out the compensation principle. However, due to the limitation of the size of the compensation pitot tube, there are great limitations in the number and location of the pressure measurement holes, and in addition, it is greatly disturbed. Compensation laws are usually complex and the correction effect is not good

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