A method and system for measuring airspeed of a subsonic aircraft

Abstract

The application discloses a kind of subsonic aircraft airspeed measurement method and system, it is related to aerospace field, the method comprises: obtaining the dynamic pressure voltage value of aircraft external gas measured by silicon piezoresistive pressure difference sensor and the temperature value of silicon piezoresistive pressure difference sensor measured by temperature sensor under different standard temperature points different standard dynamic pressure pressure value;Characteristic coefficient value of each subset is calculated;According to the characteristic coefficient value of subset and the dynamic pressure voltage value and temperature value in subset, the uncorrected dynamic pressure corresponding to each subset is calculated;Uncorrected dynamic pressure is corrected and calibrated, and the calibrated dynamic pressure corresponding to each subset is obtained;Set range dynamic pressure is calculated, and set range dynamic pressure is obtained by total pressure value minus static pressure value;Target dynamic pressure is calculated according to calibrated dynamic pressure and set range dynamic pressure;According to target dynamic pressure, the airspeed corresponding to each target dynamic pressure is determined, and the high-precision measurement of subsonic aircraft airspeed is realized.

Description

Technical Field

[0001] The present invention relates to the field of aerospace, and in particular to a method and system for measuring the airspeed of a subsonic aircraft. Background Art

[0002] Aircraft rely on the real-time relative motion between themselves and the surrounding airflow to complete flight maneuvers. Airspeed is an extremely important parameter during each phase of an aircraft's takeoff, climb, cruise, and landing. It not only represents the aircraft's speed but is also directly related to its lift, low-speed warnings, and overspeed alerts, playing a crucial role in ensuring flight safety.

[0003] Airspeed is primarily measured by an air data system (ADS). Aircraft dynamic pressure is the basis for ADS airspeed calculations. According to Bernoulli's equation, the lower the airspeed, the higher the ADS dynamic pressure measurement accuracy requirements. Currently, traditional ADS dynamic pressure measurement accuracy is limited to 60 Pa, resulting in significant airspeed errors. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for measuring the airspeed of a subsonic aircraft, which can achieve high-precision measurement of the airspeed of a subsonic aircraft.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] In a first aspect, the present invention provides a method for measuring the airspeed of a subsonic aircraft, comprising:

[0007] Obtaining the dynamic pressure voltage value of the aircraft external gas measured by the silicon piezoresistive pressure difference sensor and the temperature value of the silicon piezoresistive pressure difference sensor measured by the temperature sensor at different standard temperature points and different standard dynamic pressure values;

[0008] Calculating a characteristic coefficient value for each subset; the subset includes a standard dynamic pressure value and a corresponding standard temperature point, a dynamic pressure voltage value, and a temperature value;

[0009] Calculating the uncorrected dynamic pressure corresponding to each subset according to the characteristic coefficient value of the subset and the dynamic pressure voltage value and temperature value in the subset;

[0010] performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each of the subsets;

[0011] Obtaining a total pressure value measured by a first silicon resonant sensor and a static pressure value measured by a second silicon resonant sensor; calculating a set range dynamic pressure, where the set range dynamic pressure is obtained by subtracting the static pressure value from the total pressure value;

[0012] Calculating the target dynamic pressure based on the calibration dynamic pressure and the set range dynamic pressure;

[0013] According to the target dynamic pressure, an airspeed corresponding to each target dynamic pressure is determined.

[0014] Optionally, performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each subset specifically includes:

[0015] A first operation is performed on each of the uncorrected dynamic pressures to obtain a calibrated dynamic pressure corresponding to each subset; the first operation is:

[0016] performing interpolation processing on the uncorrected dynamic pressure and the temperature respectively to obtain error correction values;

[0017] performing correction processing on the uncorrected dynamic pressure and the error correction value to obtain a corrected dynamic pressure;

[0018] Obtaining a first correction value and a second correction value; the first correction value is used to calibrate the zero value of the silicon piezoresistive pressure differential sensor; the second correction value is used to calibrate the full-scale pressure value of the silicon piezoresistive pressure differential sensor;

[0019] calibrating the first correction value, the second correction value and the corrected dynamic pressure to obtain a calibrated dynamic pressure;

[0020] determining whether the calibration dynamic pressure is in the first interval, and obtaining a first determination result;

[0021] If the first judgment result indicates that the calibration dynamic pressure is in the first interval, the calibration dynamic pressure is determined as the target dynamic pressure; the first interval is [-T+0.2, T-0.2], T is the pressure at the full-scale output of the silicon piezoresistive pressure sensor, in kPa.

[0022] Optionally, the calculation formula of the uncorrected dynamic pressure is:

[0023]

[0024] Where: V qc is the voltage value of the dynamic pressure, in V;

[0025] is the square of the voltage value of the dynamic pressure; T qc is the temperature, is the square of the temperature, is the cube of the temperature, It is the fourth power of temperature, in °C; K1~K15 are characteristic coefficient values.

[0026] Optionally, the calculation formula for the corrected dynamic pressure is:

[0027] Qcyi=Qcys+ΔQcy;

[0028] Where: Qcys is the uncorrected dynamic pressure, unit is kPa; ΔQcy is the error correction value, unit is kPa; Qcyi is the corrected dynamic pressure, unit is kPa.

[0029] Optionally, calibrating the first correction value, the second correction value, and the corrected dynamic pressure to obtain a calibrated dynamic pressure specifically includes:

[0030] determining whether the first correction value and the second correction value are both 0, to obtain a second determination result;

[0031] If the second judgment result indicates that the first correction value and the second correction value are both 0, the calibration dynamic pressure is determined according to the first operation, and the calculation formula of the first operation is:

[0032] Qcji=Qcyi;

[0033] If the second judgment result indicates that the first correction value and the second correction value are not both zero, the calibration dynamic pressure is determined according to a second operation. The calculation formula of the second operation is:

[0034]

[0035] Where: Qcyi is the corrected dynamic pressure, in kPa; Qcji is the calibration dynamic pressure, in kPa; T is the pressure at the full-scale output of the silicon piezoresistive pressure sensor, in kPa; qcz is the first correction value; qcf is the second correction value.

[0036] Optionally, the calculation formula for the set range dynamic pressure is:

[0037] Qcib=Pti-Psi;

[0038] Wherein: Qcib is the set range dynamic pressure, in kPa; Pti is the total pressure value, in kPa, measured by the first silicon resonant pressure sensor; Psi is the static pressure value, in kPa, measured by the second silicon resonant pressure sensor.

[0039] Optionally, calculating the target dynamic pressure according to the calibration dynamic pressure and the set range dynamic pressure includes:

[0040] If the first judgment result indicates that the calibration dynamic pressure is not within the first interval, then calculating the set range dynamic pressure and judging whether the calibration dynamic pressure is within a second interval to obtain a third judgment result; the second interval is [-∞, T-0.2];

[0041] If the third judgment result indicates that the calibration dynamic pressure is within the second interval, the first weight factor is calculated according to the first formula, which is:

[0042] Aw=1;

[0043] If the third judgment result indicates that the calibration dynamic pressure is not within the second interval, then determining whether the calibration dynamic pressure is within a third interval to obtain a fourth judgment result; the third interval is [T-0.2, T].

[0044] If the fourth judgment result indicates that the calibration dynamic pressure is within the third interval, the first weight factor is calculated according to the second formula, which is:

[0045] Aw=-5*Qcji+5T;

[0046] If the fourth judgment result indicates that the calibration dynamic pressure is not within the third interval, the second weight factor is calculated according to the third formula; the third formula is:

[0047] Bw=1;

[0048] The target dynamic pressure is calculated according to the first weight factor, the second weight factor, the set range dynamic pressure, and the calibration dynamic pressure. The calculation formula of the target dynamic pressure is:

[0049] Qc=Aw*Qcji+Bw*Qcib;

[0050] Where: Qc is the target dynamic pressure, unit is kPa; Qcji is the calibration dynamic pressure, unit is kPa; Qcib is the set range dynamic pressure, unit is kPa; Aw is the first weight factor; Bw is the second weight factor.

[0051] Optionally, determining the airspeed corresponding to each target dynamic pressure according to the target dynamic pressure specifically includes:

[0052] According to the formula Calculate the airspeed.

[0053] Where: Qc is the target dynamic pressure, in kPa; Vi is the airspeed, in kilometers per hour (km / h); Pn is the standard atmospheric pressure at sea level, equal to 101.325 kPa; k is the adiabatic index, equal to 1.4; Cn is the standard speed of sound at sea level, equal to 1225.0584 km / h.

[0054] In a second aspect, the present invention provides a subsonic aircraft airspeed measurement system, comprising:

[0055] A first data acquisition module acquires the dynamic pressure voltage value of the aircraft external gas measured by the silicon piezoresistive pressure difference sensor at different standard temperature points and different standard dynamic pressure values, and the temperature value of the silicon piezoresistive pressure difference sensor measured by the temperature sensor;

[0056] A first data calculation module calculates a characteristic coefficient value of each subset; the subset includes a standard dynamic pressure value and a corresponding standard temperature point, a dynamic pressure voltage value, and a temperature value;

[0057] a second data calculation module, calculating the uncorrected dynamic pressure corresponding to each subset according to the characteristic coefficient value of the subset and the dynamic pressure voltage value and temperature value in the subset;

[0058] a data processing module, performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each of the subsets;

[0059] A second data acquisition module acquires a total pressure value measured by the first silicon resonant sensor and a static pressure value measured by the second silicon resonant sensor; and calculates a set range dynamic pressure, where the set range dynamic pressure is obtained by subtracting the static pressure value from the total pressure value;

[0060] a third data calculation module, for calculating a target dynamic pressure based on the calibration dynamic pressure and the set range dynamic pressure;

[0061] The fourth data calculation module determines the airspeed corresponding to each target dynamic pressure according to the target dynamic pressure.

[0062] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0063] The present invention provides a method and system for measuring the airspeed of a subsonic aircraft, the method comprising: obtaining dynamic pressure-voltage values ​​of the aircraft's external gas measured by a silicon piezoresistive pressure differential sensor at different standard temperature points and different standard dynamic pressure values, and a temperature value of the silicon piezoresistive pressure differential sensor measured by a temperature sensor; calculating a characteristic coefficient value of each subset; the subset comprises a standard dynamic pressure value and corresponding standard temperature points, dynamic pressure-voltage values, and temperature values; calculating an uncorrected dynamic pressure corresponding to each subset based on the characteristic coefficient value of the subset and the dynamic pressure-voltage values ​​and temperature values ​​in the subset; performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each subset; obtaining a total pressure value measured by a first silicon resonant sensor and a static pressure value measured by a second silicon resonant sensor; calculating a set range dynamic pressure, the set range dynamic pressure being obtained by subtracting the static pressure value from the total pressure value; calculating a target dynamic pressure based on the calibrated dynamic pressure and the set range dynamic pressure; and determining the airspeed corresponding to each target dynamic pressure based on the target dynamic pressure. The present invention designs a new airspeed measurement architecture and measurement method based on a silicon piezoresistive pressure differential sensor and two silicon resonant pressure sensors, and designs a set of compensation and calibration algorithms for the silicon piezoresistive pressure differential sensor, which solves the problem of large measurement errors at low airspeeds and realizes high-precision measurement of the airspeed of subsonic aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0065] Figure 1 Schematic diagram of a flow chart of a method for measuring airspeed of a subsonic aircraft according to the present invention;

[0066] Figure 2 This is a model diagram of a subsonic aircraft airspeed measurement according to the present invention;

[0067] Figure 3 The figure is a flow chart of a subsonic aircraft airspeed measurement system according to the present invention.

[0068] Explanation of symbols in the figure:

[0069] 1. Gas path module, 2. Sensor combination, 3. Power module, 4. Core processing module, 5. First total pressure gas path pipeline, 6. First three-way pipe nozzle, 7. Second total pressure gas path pipeline, 8. Third total pressure gas path pipeline, 9. First static pressure gas path pipeline, 10. Second three-way pipe nozzle, 11. Second static pressure gas path pipeline, 12. Third static pressure gas path pipeline, 13. First silicon resonant pressure sensor, 14. Silicon piezoresistive pressure differential sensor, 15. Second silicon resonant pressure sensor, 16. Second-order low-pass filter circuit, 17. Amplifier circuit, 18. AD conversion chip, 19. FPGA, 20. CPU. DETAILED DESCRIPTION

[0070] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0071] The purpose of the present invention is to provide a subsonic aircraft airspeed measurement method and system to achieve high-precision subsonic aircraft airspeed measurement.

[0072] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] Example 1

[0074] Figure 1 The figure is a flow chart of a method for measuring the airspeed of a subsonic aircraft according to the present invention.

[0075] like Figure 1 As shown, a method for measuring the airspeed of a subsonic aircraft provided by the first embodiment of the present invention includes:

[0076] Step 100: Obtain the dynamic pressure voltage values ​​of the aircraft's external atmosphere measured by the silicon piezoresistive differential pressure sensor and the temperature value of the silicon piezoresistive differential pressure sensor at different standard temperature points and standard dynamic pressure values. Based on a comprehensive consideration of the aircraft's flight altitude, accuracy requirements, and manual workload, eight temperature points were selected; more points improves accuracy. Based on a comprehensive consideration of the aircraft's dynamic pressure range, accuracy requirements, and manual workload, ten standard pressure points were selected, evenly distributed within the actual operating range. This step primarily serves to fit the characteristic coefficients of the formula in Step 200, addressing the temperature drift issue of the silicon piezoresistive differential pressure sensor. The experimental data for fitting the characteristic coefficients is shown in Table 1.

[0077] Table 1 Characteristic coefficient fitting test data table

[0078]

[0079]

[0080]

[0081] Step 200: Calculate the characteristic coefficient value of each subset; the subset includes a standard dynamic pressure value and a corresponding standard temperature point, a dynamic pressure voltage value and a temperature value.

[0082] Step 300: Calculate the uncorrected dynamic pressure corresponding to each subset according to the characteristic coefficient value of the subset and the dynamic pressure voltage value and temperature value in the subset.

[0083] Step 400: performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each of the subsets.

[0084] Step 500: Obtain a total pressure value measured by a first silicon resonant sensor and a static pressure value measured by a second silicon resonant sensor; and calculate a set range dynamic pressure, where the set range dynamic pressure is obtained by subtracting the static pressure value from the total pressure value.

[0085] Step 600: Calculating a target dynamic pressure based on the calibration dynamic pressure and the set range dynamic pressure;

[0086] Step 700: Determine the airspeed corresponding to each target dynamic pressure according to the target dynamic pressure.

[0087] Specifically, performing correction and calibration processing on the uncorrected dynamic pressure to obtain the calibrated dynamic pressure corresponding to each subset includes:

[0088] A first operation is performed on each of the uncorrected dynamic pressures to obtain a calibrated dynamic pressure corresponding to each subset; the first operation is:

[0089] The linear interpolation table of error correction value of silicon piezoresistive pressure difference sensor is obtained by calculation:

[0090] Different standard pressure values ​​were applied at different standard temperatures to obtain the uncorrected dynamic pressure. The error correction value was obtained by subtracting the uncorrected dynamic pressure from the standard pressure value. The uncorrected dynamic pressure and temperature values ​​were interpolated. The temperature points were 70°C, 45°C, 25°C, -25°C, and -45°C; the pressure intervals for the differential pressure sensor were: -0.15 kPa, 0 kPa, 0.15 kPa, 0.3 kPa, 0.45 kPa, 0.6 kPa, 0.75 kPa, 0.9 kPa, 1.05 kPa, and 1.25 kPa. The calculation table for the linear interpolation of the error correction values ​​is shown in Table 2.

[0091] Table 2 ΔQcy linear interpolation value calculation table

[0092]

[0093]

[0094] Correction processing is performed on the uncorrected dynamic pressure and the error correction value to obtain a corrected dynamic pressure.

[0095] A first correction value and a second correction value are obtained; the first correction value is used to calibrate the zero value of the silicon piezoresistive pressure differential sensor; and the second correction value is used to calibrate the full-scale pressure value of the silicon piezoresistive pressure differential sensor.

[0096] The calibrated dynamic pressure is obtained by calibration according to the first correction value, the second correction value and the corrected dynamic pressure.

[0097] It is determined whether the calibration dynamic pressure is in a first interval to obtain a first determination result.

[0098] If the first judgment result indicates that the calibration dynamic pressure is in the first interval, the calibration dynamic pressure is determined as the target dynamic pressure; the first interval is [-T+0.2, T-0.2], T is the pressure at the full-scale output of the silicon piezoresistive pressure sensor, in kPa.

[0099] Specifically, the calculation formula of the uncorrected dynamic pressure is:

[0100]

[0101] Where: V qc is the voltage value of the dynamic pressure, the unit is V.

[0102] is the square of the voltage value of the dynamic pressure; T qc is the temperature, is the square of the temperature, is the cube of the temperature, It is the fourth power of temperature, in °C; K1~K15 are characteristic coefficient values.

[0103] Specifically, the calculation formula of the corrected dynamic pressure is:

[0104] Qcyi=Qcys+ΔQcy。

[0105] Where: Qcys is the uncorrected dynamic pressure, unit is kPa; ΔQcy is the error correction value, unit is kPa; Qcyi is the corrected dynamic pressure, unit is kPa.

[0106] Specifically, the calibrating the first correction value, the second correction value, and the corrected dynamic pressure to obtain the calibrated dynamic pressure includes:

[0107] It is determined whether the first correction value and the second correction value are both 0 to obtain a second determination result.

[0108] If the second judgment result indicates that the first correction value and the second correction value are both 0, the calibration dynamic pressure is determined according to the first operation, and the calculation formula of the first operation is:

[0109] Qcji=Qcyi。

[0110] If the second judgment result indicates that the first correction value and the second correction value are not both zero, the calibration dynamic pressure is determined according to a second operation. The calculation formula of the second operation is:

[0111]

[0112] Where: Qcyi is the corrected dynamic pressure, in kPa; Qcji is the calibration dynamic pressure, in kPa; T is the pressure at the full-scale output of the silicon piezoresistive pressure sensor, in kPa; qcz is the first correction value; qcf is the second correction value.

[0113] Specifically, the calculation formula for the set range dynamic pressure is:

[0114] Qcib=Pti-Psi.

[0115] Where: Qcib is the set range dynamic pressure, in kPa; Pti is the total pressure, in kPa, measured by a silicon resonant pressure sensor that measures total pressure; Psi is the static pressure, in kPa, measured by a silicon resonant pressure sensor that measures static pressure.

[0116] Specifically, the target dynamic pressure is calculated based on the calibration dynamic pressure and the set range dynamic pressure, including:

[0117] If the first judgment result indicates that the calibration dynamic pressure is not within the first interval, the set range dynamic pressure is calculated, and it is determined whether the calibration dynamic pressure is within the second interval to obtain a third judgment result; the second interval is [-∞, T-0.2].

[0118] If the third judgment result indicates that the calibration dynamic pressure is within the second interval, the first weight factor is calculated according to the first formula, which is:

[0119] Aw=1.

[0120] If the third judgment result indicates that the calibration dynamic pressure is not within the second interval, it is determined whether the calibration dynamic pressure is within the third interval to obtain a fourth judgment result; the third interval is [T-0.2, T].

[0121] If the fourth judgment result indicates that the calibration dynamic pressure is within the third interval, the first weight factor is calculated according to the second formula, which is:

[0122] Aw=-5*Qcji+5T.

[0123] If the fourth judgment result indicates that the calibration dynamic pressure is not within the third interval, the second weight factor is calculated according to the third formula; the third formula is:

[0124] Bw=1.

[0125] The target dynamic pressure is calculated according to the first weight factor, the second weight factor, the set range dynamic pressure, and the calibration dynamic pressure. The calculation formula of the target dynamic pressure is:

[0126] Qc=Aw*Qcji+Bw*Qcib.

[0127] Where: Qc is the target dynamic pressure, unit is kPa; Qcji is the calibration dynamic pressure, unit is kPa; Qcib is the set range dynamic pressure, unit is kPa; Aw is the first weight factor; Bw is the second weight factor.

[0128] Specifically, determining the airspeed of each target dynamic pressure according to the target dynamic pressure includes:

[0129] According to the formula Calculate the airspeed.

[0130] Where: Qc is the target dynamic pressure, in kPa; Vi is the airspeed, in kilometers per hour (km / h); Pn is the standard atmospheric pressure at sea level, equal to 101.325 kPa; k is the adiabatic index, equal to 1.4; Cn is the standard speed of sound at sea level, equal to 1225.0584 km / h.

[0131] Example 2

[0132] Figure 2 This is a model diagram of a subsonic aircraft airspeed measurement according to the present invention.

[0133] like Figure 2 As shown, the subsonic aircraft primarily consists of a pneumatic module 1, a sensor assembly 2, a power module 3, and a core processing module 4. Its primary operating principle is as follows: pneumatic module 1 transmits the aircraft's total and static pressures to sensor assembly 2, which then converts the pressures into total, static, and dynamic pressure signals. Furthermore, core processing module 4 processes, collects, and calculates the pressure signals to determine the aircraft's airspeed. Power module 3 provides power to the entire measurement system.

[0134] The second gas path module 1 of this embodiment primarily consists of a first three-way pipe nozzle 6 and a second three-way pipe nozzle 10. The input end of the first three-way pipe nozzle 6 is connected to an external sensor via a first total pressure gas line 5. The output end is connected to a first silicon resonant pressure sensor 13 via a second total pressure gas line 7, and to the positive terminal of a silicon piezoresistive differential pressure sensor 14 via a third total pressure gas line 8. The input end of the second three-way pipe nozzle 10 is connected to an external sensor via a first static pressure gas line 9. The output end is connected to a silicon piezoresistive differential pressure sensor 14 via a second static pressure gas line 11, and to a second silicon resonant pressure sensor 15 via a third static pressure gas line 11.

[0135] The sensor assembly 2 described in this second example primarily consists of a first silicon resonant pressure sensor 13, a silicon piezoresistive differential pressure sensor 14, and a second silicon resonant pressure sensor 15. The first silicon resonant pressure sensor 13 is connected to the first three-way pipe nozzle 6 via the second total pressure gas line 7 and is connected to the core processing module 4 and the power module 3 via cables. The silicon piezoresistive differential pressure sensor 14 is connected to the first three-way pipe nozzle 6 via the third total pressure gas line 8 and is connected to the second three-way pipe nozzle 10 via the second static pressure gas line 11 and is connected to the core processing module 4 and the power module 3 via cables. The second silicon resonant pressure sensor 15 is connected to the second three-way pipe nozzle 10 via the third static pressure gas line 12 and is connected to the core processing module 4 and the power module 3 via cables.

[0136] The core processing module 4 is mainly composed of a second-order low-pass filter circuit 16, an amplifier circuit 17, an AD conversion chip 18, an FPGA 19, and a CPU 20. The core processing module 4 is connected to the first silicon resonant pressure sensor 13, the silicon piezoresistive pressure difference sensor 14, the second silicon resonant pressure sensor 15, and the power module 3 via cables.

[0137] The power supply module 3 mainly provides the required power for the first silicon resonant pressure sensor 13 , the silicon piezoresistive pressure difference sensor 14 , the second silicon resonant pressure sensor 15 , and the core processing module 4 .

[0138] Example 3

[0139] In order to execute the method corresponding to the above-mentioned embodiment 1 and achieve the corresponding functions and technical effects, a subsonic aircraft airspeed measurement system is provided below.

[0140] like Figure 3 As shown, the third embodiment of the present invention provides a subsonic aircraft airspeed measurement system, including:

[0141] The first data acquisition module 1 acquires the dynamic pressure voltage value of the aircraft external gas measured by the silicon piezoresistive pressure difference sensor at different standard temperature points and different standard dynamic pressure values, and the temperature value of the silicon piezoresistive pressure difference sensor measured by the temperature sensor;

[0142] The first data calculation module 2 calculates the characteristic coefficient value of each subset; the subset includes the standard dynamic pressure value and the corresponding standard temperature point, dynamic pressure voltage value and temperature value;

[0143] A second data calculation module 3 calculates the uncorrected dynamic pressure corresponding to each subset according to the characteristic coefficient value of the subset and the dynamic pressure voltage value and temperature value in the subset;

[0144] A data processing module 4 performs correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each subset;

[0145] The second data acquisition module 5 acquires the total pressure value measured by the first silicon resonant sensor and the static pressure value measured by the second silicon resonant sensor; calculates a set range dynamic pressure, where the set range dynamic pressure is obtained by subtracting the static pressure value from the total pressure value;

[0146] A third data calculation module 6 calculates the target dynamic pressure according to the calibration dynamic pressure and the set range dynamic pressure;

[0147] The fourth data calculation module 7 determines the airspeed corresponding to each target dynamic pressure according to the target dynamic pressure.

[0148] The present invention provides a method and system for measuring the airspeed of a subsonic aircraft, which has the following beneficial effects:

[0149] 1. This paper designs a new airspeed measurement architecture and measurement method based on a silicon piezoresistive pressure differential sensor and two silicon resonant pressure sensors, and designs a set of compensation and calibration algorithms for the silicon piezoresistive pressure differential sensor, which solves the problem of large measurement errors at low airspeeds and realizes high-precision measurement of subsonic aircraft.

[0150] 2. It can solve the temperature drift and time drift problems of silicon piezoresistive differential pressure sensors. At the same time, the silicon resonant pressure sensor has good long-term stability, and the measurement system has good long-term stability.

[0151] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0152] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for measuring the airspeed of a subsonic aircraft, characterized in that: include: Obtaining the dynamic pressure voltage value of the aircraft external gas measured by the silicon piezoresistive pressure difference sensor and the temperature value of the silicon piezoresistive pressure difference sensor measured by the temperature sensor at different standard temperature points and different standard dynamic pressure values; Calculating a characteristic coefficient value for each subset; the subset includes a standard dynamic pressure value and a corresponding standard temperature point, a dynamic pressure voltage value, and a temperature value; Calculating the uncorrected dynamic pressure corresponding to each subset according to the characteristic coefficient value of the subset and the dynamic pressure voltage value and temperature value in the subset; performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each of the subsets; Obtaining a total pressure value measured by the first silicon resonant sensor and a static pressure value measured by the second silicon resonant sensor; Calculating a set range dynamic pressure, where the set range dynamic pressure is obtained by subtracting the static pressure value from the total pressure value; Calculating a target dynamic pressure based on the calibration dynamic pressure and the set range dynamic pressure; determining an airspeed corresponding to each target dynamic pressure according to the target dynamic pressure; The performing correction and calibration processing on the uncorrected dynamic pressure to obtain the calibrated dynamic pressure corresponding to each subset specifically includes: A first operation is performed on each of the uncorrected dynamic pressures to obtain a calibrated dynamic pressure corresponding to each subset; the first operation is: performing interpolation processing on the uncorrected dynamic pressure and the temperature respectively to obtain error correction values; performing correction processing on the uncorrected dynamic pressure and the error correction value to obtain a corrected dynamic pressure; Obtaining a first correction value and a second correction value; the first correction value is used to calibrate the zero value of the silicon piezoresistive pressure differential sensor; the second correction value is used to calibrate the full-scale pressure value of the silicon piezoresistive pressure differential sensor; calibrating the first correction value, the second correction value and the corrected dynamic pressure to obtain a calibrated dynamic pressure; determining whether the calibration dynamic pressure is in the first interval, and obtaining a first determination result; If the first judgment result indicates that the calibration dynamic pressure is within the first interval, the calibration dynamic pressure is determined as the target dynamic pressure; the first interval is [-T+0.2, T-0.2], where T is the pressure at the full-scale output of the silicon piezoresistive pressure sensor, in kPa; The calculation formula of the corrected dynamic pressure is: ； in: is the uncorrected dynamic pressure, in kPa; is the error correction value, the unit is kPa; Qcyi is the corrected dynamic pressure, the unit is kPa; The calibrating the first correction value, the second correction value, and the corrected dynamic pressure to obtain the calibrated dynamic pressure specifically includes: determining whether the first correction value and the second correction value are both 0, to obtain a second determination result; If the second judgment result indicates that the first correction value and the second correction value are both 0, the calibration dynamic pressure is determined according to the first operation, and the calculation formula of the first operation is: ； If the second judgment result indicates that the first correction value and the second correction value are not both zero, the calibration dynamic pressure is determined according to a second operation. The calculation formula of the second operation is: ； Where: Qcyi is the corrected dynamic pressure, in kPa; Qcji is the calibration dynamic pressure, in kPa; T is the pressure at the full-scale output of the silicon piezoresistive pressure sensor, in kPa; qcz is the first correction value; qcf is the second correction value; The calculation formula for the set range dynamic pressure is: ； in: To set the range dynamic pressure, the unit is kPa; is the total pressure value, in kPa, measured by the first silicon resonant pressure sensor; is the static pressure value, in kPa, measured by the second silicon resonant pressure sensor; The target dynamic pressure is calculated based on the calibration dynamic pressure and the set range dynamic pressure, including: If the first judgment result indicates that the calibration dynamic pressure is not within the first interval, the set range dynamic pressure is calculated, and it is determined whether the calibration dynamic pressure is within a second interval to obtain a third judgment result; the second interval is [-∞, -T+0.2); If the third judgment result indicates that the calibration dynamic pressure is within the second interval, the first weight factor is calculated according to the first formula, which is: Aw=1; If the third judgment result indicates that the calibration dynamic pressure is not within the second interval, it is determined whether the calibration dynamic pressure is within the third interval to obtain a fourth judgment result; the third interval is (T-0.2, T]; If the fourth judgment result indicates that the calibration dynamic pressure is within the third interval, the first weight factor is calculated according to the second formula, which is: ； If the fourth judgment result indicates that the calibration dynamic pressure is not within the third interval, the second weight factor is calculated according to the third formula; the third formula is: ； The target dynamic pressure is calculated according to the first weight factor, the second weight factor, the set range dynamic pressure, and the calibration dynamic pressure. The calculation formula of the target dynamic pressure is: ； in: is the target dynamic pressure, in kPa; is the calibration dynamic pressure, the unit is kPa; To set the range dynamic pressure, the unit is kPa; is the first weight factor; is the second weight factor.

2. The method for measuring the airspeed of a subsonic aircraft according to claim 1, wherein: The calculation formula of the uncorrected dynamic pressure is: ； in: is the voltage value of dynamic pressure, unit is V; is the temperature, is the square of the temperature, is the cube of the temperature, It is the fourth power of temperature, in °C; K1~K15 are characteristic coefficient values.

3. The method for measuring the airspeed of a subsonic aircraft according to claim 1, wherein: Determining the standard temperature point and airspeed corresponding to each standard dynamic pressure value according to the target dynamic pressure specifically includes: According to the formula Calculate the airspeed, and determine the standard temperature point and airspeed corresponding to each standard dynamic pressure value based on the corresponding relationship between the airspeed and the standard dynamic pressure value; in: is the target dynamic pressure, in kPa; is the airspeed in kilometers per hour (km / h); Pn is the standard atmospheric pressure at sea level, which is equal to 101.325 kPa; k is the adiabatic index, which is equal to 1.4; Cn is the standard speed of sound at sea level, which is equal to 1225.0584 km / h.

4. A subsonic aircraft airspeed measurement system, used to implement the subsonic aircraft airspeed measurement method according to any one of claims 1 to 3, characterized in that: include: A first data acquisition module acquires the dynamic pressure voltage value of the aircraft external gas measured by the silicon piezoresistive pressure difference sensor at different standard temperature points and different standard dynamic pressure values, and the temperature value of the silicon piezoresistive pressure difference sensor measured by the temperature sensor; A first data calculation module calculates a characteristic coefficient value of each subset; the subset includes a standard dynamic pressure value and a corresponding standard temperature point, a dynamic pressure voltage value, and a temperature value; a second data calculation module, calculating the uncorrected dynamic pressure corresponding to each subset according to the characteristic coefficient value of the subset and the dynamic pressure voltage value and temperature value in the subset; a data processing module, performing correction and calibration processing on the uncorrected dynamic pressure to obtain a calibrated dynamic pressure corresponding to each of the subsets; a second data acquisition module, acquiring a total pressure value measured by the first silicon resonant sensor and a static pressure value measured by the second silicon resonant sensor; Calculating a set range dynamic pressure, where the set range dynamic pressure is obtained by subtracting the static pressure value from the total pressure value; a third data calculation module, for calculating a target dynamic pressure based on the calibration dynamic pressure and the set range dynamic pressure; The fourth data calculation module determines the airspeed corresponding to each target dynamic pressure according to the target dynamic pressure.

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