A method for correcting aircraft altitude based on atmospheric data
By combining pitot tube and inertial barometric altitude measurements, and utilizing Fourier filtering and weighted averaging techniques, the problem of inaccurate aircraft altitude measurement was solved, achieving higher precision altitude measurement and ensuring flight safety.
Patent Information
- Application Number
- CN202211742590.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-30
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2042-12-30
AI Technical Summary
Inaccurate altitude measurement by the aircraft's pitot tube can lead to potentially serious flight accidents.
By combining the pitot tube pressure altitude and the inertial pressure altitude, Fourier filtering is used for data processing, and the pressure altitude is corrected by weighted averaging the difference in inertial pressure altitude.
This improves the accuracy of aircraft altitude measurement, ensuring that pilots can adjust flight attitude in a timely manner and avoid accidents.
Smart Images
Figure CN115979213B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of measurement technology, and in particular relates to a method for correcting aircraft altitude based on atmospheric data. Background Technology
[0002] Aircraft primarily use barometric altimeters and radio altimeters for altitude measurement. Radio altimeters measure the distance from the aircraft to the ground, providing more accurate results when the aircraft is close to the ground, but are significantly affected by flight attitude. Barometric altimeters establish a conversion relationship between air pressure and altitude, but air pressure is greatly affected by time and temperature. With technological advancements and the application of inertial navigation and satellite systems on aircraft, we can establish a high-precision altitude measurement system using barometric altimeters and inertial navigation, allowing for more accurate measurement of aircraft barometric altitude. Summary of the Invention
[0003] The purpose of this invention is to solve the problem of inaccurate altitude measurement by the pitot tube of an aircraft, which may lead to serious flight accidents. A high-precision altitude measurement method is provided, which effectively allows pilots to obtain accurate altitude information of the aircraft. By comparing this information with the terrain altitude at the current latitude and longitude, pilots can make timely adjustments, thus helping to effectively prevent flight accidents.
[0004] In view of this, according to one aspect of the present invention, a method for correcting aircraft altitude based on atmospheric data is provided, comprising: step S1: obtaining the current pitot tube pressure altitude Hp and the previous nth pitot tube pressure altitude Hpn, where n is a first preset value; obtaining the current inertial pressure altitude HINS and the previous mth inertial pressure altitude HINSm, where m is a second preset value; step S2: performing Fourier filtering on the current pitot tube pressure altitude Hp and the previous Nth pitot tube pressure altitude Hpn to form the current pitot tube Fourier pressure altitude Hpff. Step S3: Determine the difference ΔHpfft between the current pitot tube Fourier transform pressure height Hpfft and the previous Nth pitot tube Fourier transform pressure height Hpnfft; determine the difference ΔHINS between the current inertial pressure height HINS and the previous mth inertial pressure height HINSm; Step S4: Determine the correction height Hc according to the following formula, Hc=Hpfft-ΔHpfft+α*ΔHINS+(1-α)*ΔHpfft; where α is the inertial pressure weighting coefficient.
[0005] Optionally, 0 < n < 15, 0 < m < 15.
[0006] Optionally, n=10.
[0007] Optionally, m=10.
[0008] The core of the barometric altitude correction algorithm is the effective combination of the barometric altitude measured by the pitot tube and the inertial pressure altitude measured by the inertial navigation system. Barometric altitude is closely related to factors such as temperature and wind speed at the location, and the inertial pressure altitude measured by the inertial navigation system is considered convergent and accurate over a short period. We apply a Fourier filter to the atmospheric pressure altitude, and then take a weighted average of the increment of the filtered altitude at a given moment with the increment of the inertial pressure altitude. This yields a more accurate barometric altitude. Attached Figure Description
[0009] Figure 1 This is a flowchart illustrating a method for correcting aircraft altitude based on atmospheric data according to an embodiment of the present invention. Detailed Implementation
[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0011] Figure 1 This is a flowchart illustrating a method for correcting aircraft altitude based on atmospheric data according to an embodiment of the present invention. Figure 1 As shown,
[0012] A method for correcting aircraft altitude based on atmospheric data is provided, including: Step S1: Obtaining the current pitot tube pressure altitude Hp and the pitot tube pressure altitude Hpn from the nth previous time, where n is a first preset value; obtaining the current inertial pressure altitude HINS and the inertial pressure altitude HINSm from the mth previous time, where m is a second preset value; Step S2: Performing Fourier filtering on the current pitot tube pressure altitude Hp and the pitot tube pressure altitude Hpn from the Nth previous time to form the current pitot tube Fourier pressure altitude Hpfft and the pitot tube pressure altitude from the nth previous time. Fourier pressure altitude Hpnfft; Step S3: Determine the difference ΔHpfft between the current pitot tube Fourier pressure altitude Hpfft and the previous Nth pitot tube Fourier pressure altitude Hpnfft; Determine the difference ΔHINS between the current inertial pressure altitude HINS and the previous mth inertial pressure altitude HINSm; Step S4: Determine the correction altitude Hc according to the following formula, Hc=Hpfft-ΔHpfft+α*ΔHINS+(1-α)*ΔHpfft; where α is the inertial pressure weighting coefficient.
[0013] Specifically, taking a Fourier filter of 128 points as an example, these 128 points have real and imaginary parts. First, when the first cycle arrives, the calculated air pressure altitude for the first cycle is assigned to the real part of all 128 points. After a Fourier transform, the data is converted from the time domain to the frequency domain, removing some points in specific frequency domains. The real and imaginary parts of the removed frequency domain points are cleared to 0. Then, an inverse Fourier transform is performed to convert the data back, resulting in another independent value. In the next cycle, when an air pressure altitude value arrives, the new air pressure altitude is assigned to the real part of the first point among the 128 points, and the imaginary part is set to 0. Step 2 is then executed again.
[0014] Optionally, 0 < n < 15, 0 < m < 15.
[0015] Optionally, n=10. The first ten beats can be used.
[0016] Optionally, m=10. The first ten beats can be used.
[0017] Current barometric altitude calculations are based on static pressure at the aircraft's location, which is significantly affected by factors such as temperature and wind speed. While inertial navigation system (INS) measurements of barometric altitude are relatively accurate over short periods, the error increases over extended periods. Based on the principles of INS altimetry, the difference in altitude measured by INS over a fixed time interval is more accurate. This difference is then weighted and averaged with the difference between the INS-measured altitude and the pitot tube-measured altitude after Fourier filtering to obtain a more accurate barometric altitude. The error range for both the original and corrected barometric altitude measurements is 15 meters.
[0018] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for correcting aircraft altitude based on atmospheric data, characterized in that, include: Step S1: Obtain the current pitot tube pressure altitude Hp and the pitot tube pressure altitude Hpn of the previous nth time, where n is a first preset value; Obtain the current inertial pressure altitude HINS and the previous m-th inertial pressure altitude HINSm of the aircraft, where m is a second preset value; Step S2: Perform Fourier filtering on the current pitot tube pressure height Hp and the first Nth pitot tube pressure height Hpn to form the current pitot tube Fourier pressure height Hpfft and the first nth pitot tube Fourier pressure height Hpnfft. Step S3: Determine the difference ΔHpfft between the current pitot tube Fourier transform pressure height Hpfft and the Nth previous pitot tube Fourier transform pressure height Hpnfft; Determine the difference ΔHINS between the current inertial pressure altitude HINS and the previous m-th inertial pressure altitude HINSm; Step S4: Determine the corrected height Hc according to the following formula. Hc=Hpfft-ΔHpfft+α*ΔHINS+(1-α)*ΔHpfft; Where α is the inertial pressure weighting coefficient.
2. The method according to claim 1, characterized in that, 0 < n < 15, 0 < m < 15.
3. The method according to claim 2, characterized in that, n=10。 4. The method according to claim 2, characterized in that, m=10。