A heading-fixed three-edge flight unmanned aerial vehicle airspeed system calibration method

Abstract

The application belongs to the field of unmanned aerial vehicle flight test, and particularly relates to a heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method. The method comprises the following steps: step one, selecting a test point in the flight envelope of the aircraft; step two, performing three-edge flight of the aircraft under the conditions corresponding to the test point, and obtaining flight data of the first edge, the second edge and the third edge in the stable level flight stage; step three, selecting multiple flight data points of the first edge, the second edge and the third edge from the flight data, obtaining the heading angle and the track angle of each flight data point, and judging whether the wind field uniformity in the flight process meets the requirements according to the heading angle and the track angle; if yes, entering step four; if no, returning to step two and re-executing the test point; step four, obtaining the ground speed of each flight data point, and calculating the wind speed according to the ground speed; step five, calculating the true airspeed in the flight process according to the wind speed and the ground speed; and step six, performing test point airspeed calibration according to the true airspeed.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of unmanned aerial vehicle flight test, and particularly relates to a heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method. BACKGROUND

[0002] The accuracy of airspeed system measurement has an extremely important influence on aircraft state monitoring, control, flight safety and the like. Most of the existing unmanned aerial vehicle systems are medium and small aircraft, and the airspeed is generally calibrated by the GPS or DGPS of the aircraft itself, and common methods include the round trip flight method and the like.

[0003] Since the airspeed calibration method based on GPS is sensitive to wind field, in order to meet the requirement of uniform wind field in the flight area as much as possible, the flight area for airspeed calibration needs to be reduced as much as possible.

[0004] Therefore, it is desirable to have a technical solution to overcome or at least alleviate at least one of the aforementioned deficiencies of the prior art. SUMMARY

[0005] The application aims to provide a heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method to solve at least one problem existing in the prior art.

[0006] The technical solution of the application is as follows:

[0007] The first aspect of the application provides a heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method, comprising:

[0008] Step one, selecting a test point in the flight envelope of the aircraft;

[0009] Step two, performing three-edge flight at a fixed heading angle under the conditions corresponding to the test point to obtain flight data of the first edge, the second edge and the third edge in the stable flight stage;

[0010] Step three, selecting multiple flight data points of the first edge, the second edge and the third edge from the flight data to obtain the heading angle and the track angle of each flight data point, and determining whether the wind field uniformity in the flight process meets the requirements according to the heading angle and the track angle;

[0011] If yes, proceed to step four;

[0012] If no, return to step two to re-perform the test point;

[0013] Step four, obtaining the ground speed of each flight data point and calculating the wind speed according to the ground speed;

[0014] Step five, calculating the true airspeed in the flight process according to the wind speed and the ground speed;

[0015] Step six, test point airspeed calibration is performed according to the vacuum speed.

[0016] In at least one embodiment of the present application, the test points are selected in multiple within the flight envelope of the aircraft.

[0017] In at least one embodiment of the present application, the conditions corresponding to the test points include aircraft type, flight altitude, flight speed.

[0018] In at least one embodiment of the present application, when the aircraft performs three-edge flight under the conditions corresponding to the test points, the first edge keeps the first heading angle unchanged, the second edge keeps the second heading angle unchanged, and the third edge keeps the third heading angle unchanged.

[0019] In at least one embodiment of the present application, when the aircraft performs three-edge flight under the conditions corresponding to the test points, the first heading angle and the second heading angle, and the second heading angle and the third heading angle differ by 90°.

[0020] In at least one embodiment of the present application, when the aircraft performs three-edge flight under the conditions corresponding to the test points, the time of the stable flight stage is 1 min.

[0021] In at least one embodiment of the present application, in step three, the heading angle and the track angle of each flight data point are obtained, and whether the wind field uniformity in the flight process meets the requirements is judged according to the heading angle and the track angle, comprising:

[0022] The first heading angle and the first track angle of each flight data point of the first edge are obtained, the absolute value ψ1 of the difference between the first heading angle and the first track angle corresponding to each flight data point is calculated, and the average value of each absolute value ψ1 is calculated

[0023] The second heading angle and the second track angle of each flight data point of the second edge are obtained, the absolute value ψ2 of the difference between the second heading angle and the second track angle corresponding to each flight data point is calculated, and the average value of each absolute value ψ2 is calculated

[0024] The third heading angle and the third track angle of each flight data point of the third edge are obtained, the absolute value ψ3 of the difference between the third heading angle and the third track angle corresponding to each flight data point is calculated, and the average value of each absolute value ψ3 is calculated

[0025] whether the following conditions are met simultaneously tolerance represents a given judgment threshold;

[0026] If yes, the wind field uniformity in the flight process meets the requirements;

[0027] If not, the wind field non-uniformity during the flight does not meet the requirement.

[0028] In at least one embodiment of the present application, in step four, the ground speed of each flight data point is obtained, and the wind speed is calculated according to the ground speed, including:

[0029] Obtain the eastward ground speed of each flight data point of the first side Northward ground speed

[0030] Obtain the eastward ground speed of each flight data point of the second side Northward ground speed

[0031] Obtain the eastward ground speed of each flight data point of the third side Northward ground speed

[0032] According to the eastward ground speed Northward ground speed Eastward ground speed Northward ground speed Eastward ground speed Northward ground speed Calculate the wind speed:

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041] wherein, is the eastward wind speed, is the northward wind speed, and n is the number of flight data points.

[0042] In at least one embodiment of the present application, in step five, the true airspeed during the flight is calculated according to the wind speed and the ground speed, including:

[0043]

[0044]

[0045] wherein V T is the true airspeed.

[0046] A second aspect of the present application provides a heading-fixed three-edge flight unmanned aerial vehicle airspeed system calibration system, comprising:

[0047] A test point selection module is configured to select a test point within a flight envelope of an aircraft.

[0048] A flight data acquisition module is configured to acquire flight data of a first edge, a second edge and a third edge in a steady stage of flight when the aircraft flies in a three-edge flight mode with a fixed heading angle under conditions corresponding to the test point.

[0049] A wind field non-uniformity determination module is configured to select a plurality of flight data points of the first edge, the second edge and the third edge from the flight data, acquire a heading angle and a track angle of each flight data point, and determine whether a wind field non-uniformity during flight meets a requirement according to the heading angle and the track angle.

[0050] If yes, a wind speed calculation module is entered.

[0051] If no, the flight data acquisition module is returned to and the test point is re-executed.

[0052] The wind speed calculation module is configured to acquire a ground speed of each flight data point and calculate a wind speed according to the ground speed.

[0053] A true airspeed calculation module is configured to calculate a true airspeed during flight according to the wind speed and the ground speed.

[0054] An airspeed calibration module is configured to perform test point airspeed calibration according to the true airspeed.

[0055] In at least one embodiment of the present application, a plurality of test points are selected within the flight envelope of the aircraft.

[0056] In at least one embodiment of the present application, the conditions corresponding to the test point include an aircraft type, a flight altitude and a flight speed.

[0057] In at least one embodiment of the present application, when the aircraft flies in the three-edge flight mode under the conditions corresponding to the test point, the first edge keeps a first heading angle unchanged, the second edge keeps a second heading angle unchanged, and the third edge keeps a third heading angle unchanged.

[0058] In at least one embodiment of the present application, when the aircraft flies in the three-edge flight mode under the conditions corresponding to the test point, the first heading angle and the second heading angle, and the second heading angle and the third heading angle are different by 90°.

[0059] In at least one embodiment of the present application, the time of the stable flight phase is 1 minute when the aircraft flies the triangular flight under the conditions corresponding to the test point.

[0060] In at least one embodiment of the present application, in the wind field non-uniformity determining module, the heading angle and the track angle of each flight data point are obtained, and whether the wind field non-uniformity in the flight process meets the requirement is determined according to the heading angle and the track angle, including:

[0061] The first heading angle and the first track angle of each flight data point of the first side are obtained, the absolute value ψ1 of the difference between the first heading angle and the first track angle corresponding to each flight data point is calculated, and the average value ψ1 of each absolute value ψ1 is calculated;

[0062] The second heading angle and the second track angle of each flight data point of the second side are obtained, the absolute value ψ2 of the difference between the second heading angle and the second track angle corresponding to each flight data point is calculated, and the average value ψ2 of each absolute value ψ2 is calculated

[0063] The third heading angle and the third track angle of each flight data point of the third side are obtained, the absolute value ψ3 of the difference between the third heading angle and the third track angle corresponding to each flight data point is calculated, and the average value ψ3 of each absolute value ψ3 is calculated

[0064] Whether the following conditions are met simultaneously is determined: tolerance represents a given determination threshold;

[0065] If yes, the wind field non-uniformity in the flight process meets the requirement;

[0066] If no, the wind field non-uniformity in the flight process does not meet the requirement.

[0067] In at least one embodiment of the present application, in the wind speed calculating module, the ground speed of each flight data point is obtained, and the wind speed is calculated according to the ground speed, including:

[0068] The eastward ground speed of each flight data point of the first side is obtained the northward ground speed

[0069] The eastward ground speed of each flight data point of the second side is obtained the northward ground speed

[0070] The eastward ground speed of each flight data point of the third side is obtained the northward ground speed

[0071] The wind speed is calculated according to the eastward ground speed the northward ground speed East ground speed North ground speed East ground speed North ground speed Calculate the wind speed:

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080] wherein, is the east wind speed, is the north wind speed, and n is the number of flight data points.

[0081] In at least one embodiment of the present application, in step five, calculating the true airspeed during flight according to the wind speed and the ground speed comprises:

[0082]

[0083]

[0084] wherein, V T is the true airspeed.

[0085] The application has at least the following beneficial technical effects:

[0086] The heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method of the present application adopts three-edge flight to meet the requirement of small flight airspace for unmanned aerial vehicles, and requires small airspace; can calculate the true airspeed during flight by analyzing the stable level flight stage data of three-edge flight, taking the minimum wind speed variance of three-edge flight as the target; and can reduce the influence of uneven wind field, so as to calculate the real true airspeed during flight, complete the airspeed calibration and effectiveness confirmation of the unmanned aerial vehicle, and improve the accuracy of airspeed calibration. BRIEF DESCRIPTION OF DRAWINGS

[0087] Figure 1FIG. 1 is a schematic diagram of the relationship among true airspeed, ground speed and wind speed in a heading-fixed three-way flight process according to an embodiment of the present application. DETAILED DESCRIPTION

[0088] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application. Identical or similar labels in the drawings represent identical or similar elements or elements with identical or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation on the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0089] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0090] The drawings will be described below in conjunction with the Figure 1 The present application will be described in further detail.

[0091] The first aspect of the present application provides a heading-fixed three-way flight unmanned aerial vehicle airspeed system calibration method, comprising the following steps:

[0092] Step one, selecting a test point in the flight envelope of the aircraft;

[0093] Step two, the aircraft performs three-way flight at a fixed heading angle under the conditions corresponding to the test point, and obtains flight data of the first side, the second side and the third side in the stable level flight stage;

[0094] Step three, selecting multiple flight data points of the first side, the second side and the third side from the flight data, obtaining the heading angle and the track angle of each flight data point, and determining whether the wind field uniformity in the flight process meets the requirements according to the heading angle and the track angle;

[0095] If yes, go to step four;

[0096] If not, return to step two and re-execute the test point;

[0097] Step four, ground speed of each flight data point is obtained, and wind speed is calculated according to the ground speed;

[0098] Step five, true airspeed in the flight process is calculated according to the wind speed and the ground speed;

[0099] Step six, test point airspeed calibration is carried out according to the true airspeed.

[0100] The heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method of the application, in step one, a plurality of test points are selected in the flight envelope of the aircraft, and the conditions corresponding to the test points include aircraft type, flight height and flight speed. A plurality of test points under different conditions are selected. In step two, the aircraft is flown in a three-edge flight under the given conditions of aircraft type, flight height and flight speed corresponding to the test points. When the aircraft is flown in a three-edge flight under the conditions corresponding to the test points, the first edge keeps the first heading angle unchanged, the second edge keeps the second heading angle unchanged, and the third edge keeps the third heading angle unchanged. The first heading angle and the second heading angle, and the second heading angle and the third heading angle are different by 90°. The time of the stable level flight stage is 1 min. The flight data of the first edge, the second edge and the third edge in the stable level flight stage under the conditions corresponding to the test points are recorded.

[0101] In the preferred embodiment of the application, in step three, a plurality of flight data points of the first edge, the second edge and the third edge are selected from the flight data. The flight data points recorded by the first edge, the second edge and the third edge in the stable level flight stage are basically consistent. n flight data points are taken in the stable level flight stage of the first edge, the second edge and the third edge, respectively.

[0102] In this embodiment, whether the wind field uniformity in the flight process meets the requirements is judged according to the heading angle and the track angle of each flight data point, as follows:

[0103] The first heading angle and the first track angle of each flight data point of the first edge are obtained. The absolute value ψ1 of the difference between the first heading angle and the first track angle corresponding to each flight data point is calculated, and the average value of each absolute value ψ1 is calculated

[0104] The second heading angle and the second track angle of each flight data point of the second edge are obtained. The absolute value ψ2 of the difference between the second heading angle and the second track angle corresponding to each flight data point is calculated, and the average value of each absolute value ψ2 is calculated

[0105] The third heading angle and the third track angle of each flight data point of the third edge are obtained. The absolute value ψ3 of the difference between the third heading angle and the third track angle corresponding to each flight data point is calculated, and the average value of each absolute value ψ3 is calculated

[0106] Determine whether the conditions are met simultaneously. tolerance represents a given decision threshold;

[0107] If so, the wind field non-uniformity during flight meets the requirements;

[0108] If not, the wind field non-uniformity during flight will not meet the requirements.

[0109] During the execution of the test site, the data may become unavailable due to wind field issues. In this case, simply select a new day with good weather and conduct the flight test again (i.e., return to step two) to re-execute the test site.

[0110] This application presents a method for calibrating the airspeed system of a three-sided flying UAV with a fixed heading angle. After the wind field non-uniformity meets the experimental requirements during flight, wind speed is calculated. The speed during the round trip is analyzed; if the wind speed is stable during flight, the vacuum speed (V) for each side of the flight is calculated. T ), wind speed (V) W ) and ground speed (V) G ) satisfy as Figure 1 The vector relationships shown are as follows: V represents velocity, ψ represents the difference between the heading angle and the trajectory angle, 1 represents the first side of flight, 2 represents the second side of flight, and 3 represents the third side of flight. Their mathematical expressions are shown in Equation (1). In this equation, the subscript T represents vacuum speed, G represents ground speed, W represents wind speed, and j represents the j-th flight side; the superscript E represents eastward speed and N represents northward speed.

[0111]

[0112] Since the vacuum velocity is equal on each side, the vacuum velocity during the round trip satisfies the relationships shown in equations (2) and (3):

[0113]

[0114]

[0115] Substituting equation (1) into equations (2) and (3), equations (4) and (5) hold true:

[0116]

[0117]

[0118] Take n flight data points during the stable level flight phases on the 1st, 2nd, and 3rd sides respectively. When the wind field is constant during flight, take any data points on either side during flight. They all satisfy the relationships in equations (4) and (5). Then, the mathematical expressions for the wind speed equations of n flight data points are shown in equations (6) and (7):

[0119]

[0120]

[0121] Let:

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128] Finally, the wind speed expression is shown as equation (8) and (9):

[0129]

[0130]

[0131] Where, is the east wind speed, is the north wind speed, and n is the number of flight data points.

[0132] According to the above analysis, in step four, the wind speed calculation process includes:

[0133] Get the east ground speed of each flight data point of the first side North ground speed

[0134] Get the east ground speed of each flight data point of the second side North ground speed

[0135] Get the east ground speed of each flight data point of the third side North ground speed

[0136] According to the east ground speed North ground speed East ground speed North ground speed East ground speed North ground speed Substitute equation (8) and (9) to calculate the wind speed.

[0137] After the wind speed in flight is obtained, the ground speed in flight is combined to obtain the true air speed in flight. The true air speed in flight is arithmetically averaged to obtain the accurate true air speed, and the calibration of the air speed system is completed.

[0138] In this embodiment, in step five, the true air speed in flight is calculated according to the wind speed calculated in step four and the ground speed in the stable straight flight stage of the outbound and inbound, and the true air speed in flight is arithmetically averaged to obtain the true true air speed under the given aircraft type, flight height and flight speed according to the calculation formula of formula (10).

[0139]

[0140]

[0141] wherein V T is the true air speed.

[0142] In step six, after the test point speed calibration under the current aircraft type, flight height and flight speed is completed, the next test point is repeated in sequence from step two to step five until the air speed calibration of all test points is completed.

[0143] The heading angle fixed three-edge flight unmanned aerial vehicle air speed system calibration method of the application completes a three-edge flight with a fixed and unchanged heading angle under the condition of a given aircraft type, flight height and flight speed. In the three-edge flight, the heading angle of the aircraft in each adjacent edge is different by 90°. The flight data such as flight height, flight speed, aircraft heading angle and aircraft track angle in the stable straight flight stage of each edge are recorded. The wind speed is judged to be stable according to the flight data calculation. If the wind speed is stable, the average ground speed of each edge is calculated, the flight data is brought into the wind speed calculation formula, the wind speed in the three-edge flight is calculated, the true true air speed is calculated according to the wind speed, and the air speed calibration is completed.

[0144] The heading angle fixed three-edge flight unmanned aerial vehicle air speed system calibration method of the application calculates the true true air speed with the minimum wind speed variance of the three-edge flight as the target, the calculated true true air speed has better robustness, and the influence of the wind field on the air speed calibration is further reduced. The requirement for the flight area is further relaxed, and the air speed system calibration of the unmanned aerial vehicle under the crosswind condition can be realized through a smaller flight area, thereby reducing the influence of the wind field on the calibration effect. The requirement for the wind field uniformity is increased, and when the wind field uniformity does not meet the test requirement, the test needs to be re-performed. The method has universality and is suitable for air speed calibration of different types of unmanned aerial vehicles.

[0145] Based on the above-mentioned heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method, the second aspect of the application provides a heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration system, comprising:

[0146] A test point selection module is configured to select a test point in a flight envelope of an aircraft.

[0147] A flight data acquisition module is configured to acquire flight data of a first edge, a second edge and a third edge in a steady flight stage when the aircraft flies in a fixed heading angle under a condition corresponding to the test point.

[0148] A wind field non-uniformity determination module is configured to select a plurality of flight data points of the first edge, the second edge and the third edge from the flight data, acquire a heading angle and a track angle of each flight data point, and determine whether the wind field non-uniformity in the flight process meets a requirement according to the heading angle and the track angle.

[0149] If yes, the wind speed calculation module is entered.

[0150] If no, the flight data acquisition module is returned to re-execute the test point.

[0151] A wind speed calculation module is configured to acquire a ground speed of each flight data point and calculate a wind speed according to the ground speed.

[0152] A true airspeed calculation module is configured to calculate a true airspeed in the flight process according to the wind speed and the ground speed.

[0153] An airspeed calibration module is configured to calibrate a test point airspeed according to the true airspeed.

[0154] The functions and specific implementation modes of each module of the heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration system of the application are described above in the heading angle fixed three-edge flight unmanned aerial vehicle airspeed system calibration method, and will not be described here.

[0155] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any changes or replacements within the technical range disclosed in the application can be easily thought of by those skilled in the art, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for calibrating the airspeed system of a triaxially flying unmanned aerial vehicle with a fixed heading angle, characterized in that, include: Step 1: Select test points within the aircraft's flight envelope; Step 2: The aircraft performs three-sided flight at a fixed heading angle under the conditions corresponding to the test point, and obtains flight data for the first, second, and third sides during the stable level flight phase; Step 3: Select multiple flight data points from the first, second, and third sides of the flight data respectively, obtain the heading angle and trajectory angle of each flight data point, and determine whether the wind field non-uniformity meets the requirements based on the heading angle and trajectory angle. If so, proceed to step four; If not, return to step two and re-execute the test point; Step 4: Obtain the ground speed at each flight data point and calculate the wind speed based on the ground speed, including: Obtain the eastward ground speed of each flight data point on the first side. Northbound ground speed Obtain the eastward ground speed of each flight data point on the second side. Northbound ground speed Obtain the eastward ground speed of each flight data point on the third side. Northbound ground speed According to the eastward ground speed Northbound ground speed Eastbound speed Northbound ground speed Eastbound speed Northbound ground speed Calculate wind speed: in, The wind speed is easterly. Here, n represents the northerly wind speed, and n represents the number of flight data points. Step 5: Calculate the vacuum speed during flight based on the wind speed and the ground speed; Step 6: Calibrate the air velocity at the test point according to the vacuum velocity.

2. The method for calibrating the airspeed system of a triaxially flying UAV with a fixed heading angle according to claim 1, characterized in that, The test points are selected from multiple points within the aircraft's flight envelope.

3. The method for calibrating the airspeed system of a triaxially flying UAV with a fixed heading angle according to claim 2, characterized in that, The conditions corresponding to the test points include aircraft configuration, flight altitude, and flight speed.

4. The method for calibrating the airspeed system of a triaxially flying UAV with a fixed heading angle according to claim 3, characterized in that, When the aircraft performs a three-way flight under the conditions corresponding to the test point, the first heading angle remains unchanged for the first side, the second heading angle remains unchanged for the second side, and the third heading angle remains unchanged for the third side.

5. The method for calibrating the airspeed system of a three-sided flying UAV with a fixed heading angle according to claim 4, characterized in that, When the aircraft performs tri-plane flight under the conditions corresponding to the test point, the first heading angle differs from the second heading angle, and the second heading angle differs from the third heading angle by 90°.

6. The method for calibrating the airspeed system of a three-sided flying UAV with a fixed heading angle according to claim 5, characterized in that, When the aircraft performs triplane flight under the conditions corresponding to the test point, the stable level flight phase lasts for 1 minute.

7. The method for calibrating the airspeed system of a three-sided flying UAV with a fixed heading angle according to claim 6, characterized in that, In step three, the heading angle and trajectory angle of each flight data point are obtained. Based on the heading angle and trajectory angle, it is determined whether the wind field non-uniformity during flight meets the requirements, including: Obtain the first heading angle and first trajectory angle for each flight data point on the first side. Calculate the absolute value ψ1 of the difference between the first heading angle and the first trajectory angle for each flight data point, and calculate the average value of each absolute value ψ1. Obtain the second heading angle and second trajectory angle for each flight data point on the second side. Calculate the absolute value ψ2 of the difference between the second heading angle and the second trajectory angle for each flight data point, and then calculate the average of these absolute values ​​ψ2. Obtain the third heading angle and third trajectory angle for each flight data point on the third side. Calculate the absolute value ψ3 of the difference between the third heading angle and the third trajectory angle for each flight data point, and then calculate the average of these absolute values ​​ψ3. Determine whether the conditions are met simultaneously. tolerance represents a given decision threshold; If so, the wind field non-uniformity during flight meets the requirements; If not, the wind field non-uniformity during flight will not meet the requirements.

8. The method for calibrating the airspeed system of a triaxially flying UAV with a fixed heading angle according to claim 7, characterized in that, Step five involves calculating the vacuum speed during flight based on the wind speed and the ground speed, including: Among them, V T It is the vacuum velocity.

9. A calibration system for the airspeed system of a three-sided flying unmanned aerial vehicle with a fixed heading angle, characterized in that, include: The test point selection module is used to select test points within the aircraft's flight envelope; The flight data acquisition module is used to acquire flight data of the first, second, and third sides during the stable level flight phase when the aircraft performs three-sided flight at a fixed heading angle under the conditions corresponding to the test point. The wind field non-uniformity determination module is used to select multiple flight data points from the first side, the second side, and the third side respectively from the flight data, obtain the heading angle and trajectory angle of each flight data point, and determine whether the wind field non-uniformity meets the requirements during the flight based on the heading angle and the trajectory angle. If so, proceed to the wind speed calculation module; If not, return to the flight data acquisition module and re-execute the test point; The wind speed calculation module is used to acquire the ground speed at each flight data point and calculate the wind speed based on the ground speed, including: Obtain the eastward ground speed of each flight data point on the first side. Northbound ground speed Obtain the eastward ground speed of each flight data point on the second side. Northbound ground speed Obtain the eastward ground speed of each flight data point on the third side. Northbound ground speed According to the eastward ground speed Northbound ground speed Eastbound speed Northbound ground speed Eastbound speed Northbound ground speed Calculate wind speed: in, The wind speed is easterly. Here, n represents the northerly wind speed, and n represents the number of flight data points. A vacuum speed calculation module is used to calculate the vacuum speed during flight based on the wind speed and the ground speed. The airspeed calibration module is used to calibrate the airspeed at the test point based on the vacuum speed.

10. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 9, characterized in that, The test points are selected within the aircraft's flight envelope.

11. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 10, characterized in that, The conditions corresponding to the test points include aircraft configuration, flight altitude, and flight speed.

12. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 11, characterized in that, When the aircraft performs a three-way flight under the conditions corresponding to the test point, the first heading angle remains unchanged for the first side, the second heading angle remains unchanged for the second side, and the third heading angle remains unchanged for the third side.

13. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 12, characterized in that, When the aircraft performs tri-plane flight under the conditions corresponding to the test point, the first heading angle differs from the second heading angle, and the second heading angle differs from the third heading angle by 90°.

14. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 13, characterized in that, When the aircraft performs triplane flight under the conditions corresponding to the test point, the stable level flight phase lasts for 1 minute.

15. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 14, characterized in that, In the wind field non-uniformity determination module, the heading angle and trajectory angle of each flight data point are acquired. Based on the heading angle and trajectory angle, it is determined whether the wind field non-uniformity during flight meets the requirements, including: Obtain the first heading angle and first trajectory angle for each flight data point on the first side. Calculate the absolute value ψ1 of the difference between the first heading angle and the first trajectory angle for each flight data point, and calculate the average value of each absolute value ψ1. Obtain the second heading angle and second trajectory angle for each flight data point on the second side. Calculate the absolute value ψ2 of the difference between the second heading angle and the second trajectory angle for each flight data point, and then calculate the average of these absolute values ​​ψ2. Obtain the third heading angle and third trajectory angle for each flight data point on the third side. Calculate the absolute value ψ3 of the difference between the third heading angle and the third trajectory angle for each flight data point, and then calculate the average of these absolute values ​​ψ3. Determine whether the conditions are met simultaneously. tolerance represents a given decision threshold; If so, the wind field non-uniformity during flight meets the requirements; If not, the wind field non-uniformity during flight will not meet the requirements.

16. The triaxial flight UAV airspeed system calibration system with fixed heading angle according to claim 15, characterized in that, Step five involves calculating the vacuum speed during flight based on the wind speed and the ground speed, including: Among them, V T It is the vacuum velocity.

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