A method for determining wind speed and direction in complex helicopter scenarios

Abstract

This invention provides a method for determining wind speed and direction in complex helicopter scenarios. The helicopter is equipped with a single-axis air intake system. The method includes: Step 1, extracting the helicopter's heading angle Ψ and eastward velocity V based on an inertial navigation system. E and northbound speed V N Step 2: Extract the comprehensive vacuum velocity V of the single-axis atmospheric engine based on the inertial navigation system. t Step 3: Based on the heading angle Ψ and eastward velocity V E Northbound speed V N and combined vacuum velocity V t Step 3: Determine wind speed and direction; Step 4: Based on the error in determining wind speed and direction in Step 3, dynamically adjust the heading angle Ψ and easterly wind speed V. WE Northbound wind speed V WN The wind speed and direction are recalculated until they are accurately determined. This invention comprehensively utilizes the eastward speed, northward speed, heading angle of the integrated navigation system, and the vacuum speed of a single-axis atmospheric engine to calculate and determine wind speed and direction, thus solving the problem of inaccurate wind speed and direction calculations in existing technologies. This invention effectively improves the accuracy of wind speed and direction output.

Description

Technical Field

[0001] This invention belongs to the field of helicopter technology, specifically relating to a method for determining wind speed and direction in complex helicopter scenarios. Background Technology

[0002] Helicopters fly using rotors. As the blades rotate in the air, they generate a downward airflow. Because the airflow speed on the upper surface of the rotor is faster than on the lower surface, an upward lift force is created, enabling the helicopter to hover or take off and land vertically. Simultaneously, the rotor's rotation generates thrust, allowing the helicopter to fly horizontally. By changing the blade angle and rotation speed, the rotor controls the helicopter's attitude and direction. Furthermore, by adjusting the angle and rotation speed, the rotor adjusts the magnitude and direction of lift and thrust, enabling the helicopter to fly forward, backward, left, or right, or to climb or descend.

[0003] In addition to the rotor, the helicopter is equipped with a tail rotor to counteract the torque generated by the rotor. The tail rotor balances the torque force of the rotor by generating an opposite torque force, thereby maintaining the stability and balance of the helicopter. The tail rotor can also control the direction of the helicopter. When the helicopter needs to turn left or right, the angle and position of the tail rotor are adjusted to generate thrust to the left or right, causing the helicopter to change direction.

[0004] Helicopters generate aerodynamic forces through the relative motion between their rotor rotation and the surrounding air, which can be decomposed into lift, torque, and horizontal force. Methods such as slipstream theory, blade element theory, and vortex theory are commonly used to analyze and calculate the interaction between the rotor and the surrounding air. Specifically: slipstream theory treats the rotor as a thrust-generating disk and the flow field affected by the rotor as a one-dimensional flow within a slipstream bounded by the disk's circumference; the relationship between thrust and required power and the velocity change within the slipstream is determined using the momentum theorem and the kinetic energy theorem. Blade element theory divides the rotor blades into many micro-segments (blade elements) and treats the relative flow around each blade element as an independent two-dimensional flow, calculating the aerodynamic forces and torques of the blade profile, then integrating along the blade radius and averaging along the azimuth to obtain the aerodynamic forces and torques of the entire rotor. Vortex theory uses a vortex system to represent the effect of the rotor blades on the surrounding air, thereby determining the induced velocity at any point in space.

[0005] The air movement caused by the rotation of the helicopter's own rotor is a complex process. In addition, single-axis air engines have poor accuracy at low speeds and cannot output airspeed in three directions, which can lead to inaccurate calculations of wind speed and direction. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies in accurately determining wind direction and speed, and to provide a method for determining wind speed and direction in complex helicopter scenarios. This method comprehensively utilizes the eastward speed, northward speed, heading angle of the integrated navigation system, and the vacuum speed of the single-axis atmospheric engine to calculate and determine wind speed and direction, thus solving the problem of inaccurate wind speed and direction calculation and effectively improving the accuracy of wind speed and direction output.

[0007] To achieve the above objectives, the technical solution provided by this invention is:

[0008] A method for determining wind speed and direction in complex helicopter scenarios, wherein the helicopter is equipped with a single-axis air compressor, the method comprising:

[0009] Step 1: Extract the helicopter's heading angle Ψ and eastward velocity V based on the inertial navigation system. E and northbound speed V N ;

[0010] Step 2: Extract the comprehensive vacuum velocity V of the single-axis atmospheric engine based on the inertial navigation system. t ;

[0011] Step 3: Based on the heading angle Ψ and eastward velocity V E Northbound speed V N and combined vacuum velocity V t Determine the wind speed and direction, specifically:

[0012] The wind speed is calculated using formula (1), and the expression is:

[0013]

[0014] In formula (1), V W V represents wind speed. WE V represents the eastward wind speed. WN Indicates northerly wind speed;

[0015] The wind direction is calculated using formula (2), and the expression is:

[0016]

[0017] In formula (2), Ψ W Indicates wind direction, V WE V represents the eastward wind speed. WN This indicates the northerly wind speed; where, if the direction of the incoming wind is defined as the wind direction, then the wind direction Ψ is determined accordingly. W as follows:

[0018] When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind direction is less than 0, the wind direction is determined as Ψ.W When the easterly wind speed is V WE =0, Northward wind speed V WN When the wind speed is <0, the wind direction is defined as 0°; when the easterly wind speed is V WE >0, northerly wind speed V WN When the wind direction is less than 0, it is determined to be 360° + Ψ. W ;

[0019] When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind speed is 0, the wind direction is determined to be 90°; when the easterly wind speed is V... WE =0, Northward wind speed V WN When the wind speed is 0, the wind direction is determined to be calm; when the easterly wind speed is V... WE >0, northerly wind speed V WN When the angle is 0, the wind direction is determined to be 270°.

[0020] When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind direction is greater than 0, the wind direction is determined to be 180° + Ψ. W When the easterly wind speed is V WE =0, Northward wind speed V WN When the wind speed is greater than 0, the wind direction is determined to be 180°; when the easterly wind speed is V... WE >0, northerly wind speed V WN When the wind direction is greater than 0, the wind direction is determined to be 180° + Ψ. W .

[0021] As a further limitation of the present invention, step one includes:

[0022] Step (11) Obtain the heading angle Ψ of the helicopter through the strapdown inertial navigation system;

[0023] Step (12) Obtain the ground speed of the helicopter relative to the Earth using the strapdown inertial navigation system, and obtain the eastward speed V of the helicopter based on the ground speed. E and northbound speed V N .

[0024] As a further limitation of the present invention, step two includes:

[0025] Step (21) Obtain the angle of attack α and sideslip angle β of the helicopter through the strapdown inertial navigation system;

[0026] Step (22) Obtain the composite vacuum velocity V of the single-axis atmospheric engine using a strapdown inertial navigation system. t Among them, the comprehensive vacuum velocity V t Including the vertical axis velocity component, the horizontal axis velocity component, and the normal axis velocity component;

[0027] Step (23) Based on the angle of attack α and sideslip angle β, the combined vacuum velocity V obtained by the single-axis atmospheric engine t The conversion is performed, and the expression is:

[0028]

[0029] In formula (3), V represents the wind speed matrix. t ×sin(β) represents the vertical velocity component, V t ×cos(α)×cos(β) represents the velocity component along the horizontal axis, -V t ×sin(α)×cos(β) represents the normal velocity component.

[0030] As a further limitation of the present invention, in formula (1) of step three, Wind speed V represents the square of the wind speed. W The larger the wind direction Ψ W The smaller the calculation error, the better.

[0031] As a further limitation of the present invention, it also includes:

[0032] Step 4: Based on the errors in wind speed and direction determined in Step 3, dynamically adjust the heading angle Ψ and the eastward wind speed V. WE Northbound wind speed V WN Re-determine the wind speed and direction until they are accurate.

[0033] As a further limitation of the present invention, in step four, the error in determining wind speed and wind direction in step three includes:

[0034] (1) The wind speed V determined in step three W When the wind is relatively small, the wind direction is Ψ W The calculation error increased sharply;

[0035] (2) When the helicopter is flying backward, sideways, turning, climbing, or descending, the wind speed V determined in step three is... W Wind direction Ψ W Simultaneous calculation errors occurred;

[0036] (3) Before the helicopter resumes high-speed flight at low speed, during short periods of maneuvering, or before the maneuvering resumes high-speed forward flight, the wind direction Ψ determined in step three. W An error occurred.

[0037] As a further limitation of the present invention, in step four, the heading angle Ψ and the easterly wind speed V are dynamically adjusted. WE Northbound wind speed V WN Re-determine wind speed and direction until they are accurately determined, including:

[0038] (1) Determine whether condition 1 is met. If condition 1 is met, cache the helicopter's current heading angle Ψ and eastward speed V every 1 second. E Northbound speed V N 1-second average easterly wind speed V WE and northerly wind speed V WN The maximum buffer time is 30 seconds; substitute the data into formula (1) and formula (2) to determine the wind speed and direction;

[0039] Among them, condition 1 is: the helicopter simultaneously meets the following conditions in complex scenarios: current ground speed > 36 km / h, comprehensive vacuum speed V t >40km / h, absolute value of (track angle - heading angle Ψ) <45°;

[0040] (2) Starting from when the cached data is full for 30 seconds, check every 1 second whether condition 2 is met. If condition 2 is met, cache the eastward wind speed V for 30 seconds. WE and northerly wind speed V WN After taking the average, record it as and If condition 2 is not met or the cached data is less than 30 seconds, then the 1-second average easterly wind speed V will be used. WE and northerly wind speed V WN Assign to and Will and Substitute into formulas (1) and (2) to determine wind speed and direction;

[0041] Among them, condition 2 is: (a) the maximum cruise speed V of the helicopter within the current 30s. xmax and minimum cruising speed V xmin The absolute value of the difference |ΔV x |≤20km / h; (b) Maximum heading H of the helicopter within the current 30s max Minimum heading H min The absolute value of the difference, |ΔH|, is ≤10°;

[0042] (3) Starting from when the cached data is full for 30 seconds, check every 1 second whether condition 3 is met. If condition 3 is met, cache the eastward wind speed V for 30 seconds. WE and northerly wind speed V WN After taking the average, record the calculation time and the 30-second average. 30-second average Current heading angle Ψ, current combined vacuum velocity V t ;like and Neither of them has been substituted into formulas (1) and (2) for calculation, then like and Since the formulas (1) and (2) have already been substituted into the calculation, then Will and Substitute into formulas (1) and (2) to determine wind speed and direction;

[0043] Among them, condition 3 is: (a) the maximum cruise speed V of the helicopter within the current 30s. xmax and minimum cruising speed V xmin The absolute value of the difference |ΔV x |≤5km / h;(b) The maximum heading H of the helicopter within the current 30s max Minimum heading H min The absolute value of the difference, |ΔH|, is ≤3°.

[0044] As a further limitation of the present invention, in step four, the heading angle Ψ and the easterly wind speed V are dynamically adjusted. WE Northbound wind speed V WN The process of re-determining wind speed and direction until they are accurately determined includes:

[0045] (4) Select the current average value of the helicopter. and Substitute into formulas (1) and (2) to determine wind speed and direction; where, and The expression is:

[0046]

[0047] In formula (4), and Obtained through step four (3). and Obtained through step (2) of the above steps;

[0048] (5) Select the current 30-second average easterly and northerly wind speeds of the helicopter after calibration compensation. and Substitute into formulas (1) and (2) to determine wind speed and direction;

[0049] (6) When condition 4 is met, the wind speed and direction determined by formulas (1) and (2) remain unchanged; wherein, condition 4 is: comprehensive vacuum speed Vt ≤40km / h, or ground speed ≤36km / h, or absolute value of deflection angle >90°.

[0050] The advantages of this invention are:

[0051] This invention comprehensively utilizes the eastward speed, northward speed, heading angle of the integrated navigation system, and the vacuum speed of the single-axis atmospheric engine to calculate and determine wind speed and direction, thus solving the problem of inaccurate wind speed and direction calculation and effectively improving the accuracy of wind speed and direction output.

[0052] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0053] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0054] Figure 1 This invention provides a method for determining wind speed and direction in complex helicopter scenarios. Figure 1 ;

[0055] Figure 2 This invention provides a method for determining wind speed and direction in complex helicopter scenarios. Figure 2 ;

[0056] Figure 3 The wind direction truth table output in step three of this invention;

[0057] Figure 4 The present invention provides a velocity vector triangle diagram for complex helicopter scenarios;

[0058] Figure 5 The wind speed and direction simulation data provided by this invention are illustrated in the figure.

[0059] Figure 6 The simulation data of the deflection angle provided by this invention is illustrated in the figure.

[0060] Figure 7 The present invention provides a diagram illustrating the speed and angle parameters of a helicopter in complex scenarios. Detailed Implementation

[0061] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0062] Please see Figure 1 and Figure 2This invention provides a method for determining wind speed and direction in complex scenarios involving helicopters. The helicopter is equipped with a single-axis air compressor. The method for determining wind speed and direction in this invention includes:

[0063] Step 1: Extract the helicopter's heading angle Ψ and eastward velocity V based on the inertial navigation system. E and northbound speed V N .

[0064] Specifically, step one of this embodiment of the invention includes:

[0065] Step (11) Obtain the helicopter's heading angle Ψ using the strapdown inertial navigation system;

[0066] Step (12) Obtain the ground speed of the helicopter relative to the Earth using the strapdown inertial navigation system, and obtain the eastward speed V of the helicopter based on the ground speed. E and northbound speed V N .

[0067] In step one of this embodiment of the invention, by reasonably setting the inertial navigation data of the strapdown inertial navigation system, optimizing the sliding filter parameters of the strapdown inertial navigation system, and dynamically self-calibrating during reciprocating flight, adaptively adjusting the weighted time scale of real-time calculation and historical data, the heading angle Ψ and eastward velocity V of the helicopter in complex scenarios are obtained. E and northbound speed V N .

[0068] Step 2: Extract the comprehensive vacuum velocity V of a single-axis atmospheric engine based on the inertial navigation system. t .

[0069] Specifically, step two in this embodiment of the invention includes:

[0070] Step (21) Obtain the helicopter's angle of attack α and sideslip angle β using the strapdown inertial navigation system;

[0071] Step (22) Obtain the composite vacuum velocity V of the single-axis atmospheric engine using a strapdown inertial navigation system. t Among them, the comprehensive vacuum velocity V t Including the vertical axis velocity component, the horizontal axis velocity component, and the normal axis velocity component;

[0072] Step (23) Based on the angle of attack α and sideslip angle β, the combined vacuum velocity V obtained by the single-axis atmospheric engine t The conversion is performed, and the expression is:

[0073]

[0074] In formula (3), V represents the wind speed matrix. t×sin(β) represents the vertical velocity component, V t ×cos(α)×cos(β) represents the velocity component along the horizontal axis, -V t ×sin(α)×cos(β) represents the normal velocity component.

[0075] In step two of this embodiment of the invention, by reasonably setting atmospheric data, the angle of attack α, sideslip angle β, and the combined vacuum velocity V of the single-axis atmospheric engine of the helicopter are obtained. t .

[0076] Step 3: Based on the heading angle Ψ and eastward velocity V E Northbound speed V N and combined vacuum velocity V t Determine the wind speed and direction. Please refer to [link / reference]. Figure 4 , specifically:

[0077] In this embodiment of the invention, wind speed is calculated using formula (1), which is expressed as:

[0078]

[0079] In formula (1), V W V represents wind speed. WE V represents the eastward wind speed. WN Indicates northerly wind speed;

[0080] In this embodiment of the invention, the wind direction is calculated using formula (2), and the expression is:

[0081]

[0082] In formula (2), Ψ W Indicates wind direction, V WE V represents the eastward wind speed. WN This indicates the northerly wind speed. For a definition of wind direction, please refer to [link to relevant documentation]. Figure 3 This determines the wind direction Ψ W as follows:

[0083] When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind direction is less than 0, the wind direction is determined as Ψ. W When the easterly wind speed is V WE =0, Northward wind speed V WN When the wind speed is <0, the wind direction is defined as 0°; when the easterly wind speed is V WE >0, northerly wind speed V WN When the wind direction is less than 0, it is determined to be 360° + Ψ. W ;

[0084] When the easterly wind speed is V WE <0, northerly wind speed VWN When the wind speed is 0, the wind direction is determined to be 90°; when the easterly wind speed is V... WE =0, Northward wind speed V WN When the wind speed is 0, the wind direction is determined to be calm; when the easterly wind speed is V... WE >0, northerly wind speed V WN When the angle is 0, the wind direction is determined to be 270°.

[0085] When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind direction is greater than 0, the wind direction is determined to be 180° + Ψ. W When the easterly wind speed is V WE =0, Northward wind speed V WN When the wind speed is greater than 0, the wind direction is determined to be 180°; when the easterly wind speed is V... WE >0, northerly wind speed V WN When the wind direction is greater than 0, the wind direction is determined to be 180° + Ψ. W .

[0086] In formula (1) of step three above in the embodiment of the present invention, Wind speed V represents the square of the wind speed. W The larger the wind direction Ψ W The smaller the calculation error, the better.

[0087] The embodiments of the present invention optimize the wind direction calculation output conditions, optimize the deflection angle calculation, and optimize the steady-state and real-time solution weighting, and optimize the wind speed and wind direction calculation output logic. The wind direction and wind speed are obtained by using formula (1) and formula (2).

[0088] Preferably, the physical quantities involved in determining wind speed and direction in this embodiment of the invention include: the eastward speed, northward speed, pitch angle, roll angle, and heading angle of the strapdown inertial navigation system, as well as the vacuum speed of the vacuum air engine. Please refer to [link / reference]. Figure 7 , Figure 7 (a) Figure 7 (b) Figure 7 (d) Figure 7 (e) shows the load factor direction, velocity vector direction, and airflow direction of the helicopter as it moves along its flight path. The helicopter's climb angle, pitch angle, and angle of attack during its motion are as follows: Figure 7 As shown in (a), the sideslip angle, track angle, and heading change angle during the helicopter's movement are as follows: Figure 7 As shown in (b), the roll angle during helicopter movement is as follows: Figure 7 As shown in (c), the angle of attack, pitch angle, and climb angle of the helicopter during its movement are as follows: Figure 7 As shown in (d), the sideslip angle, track angle, and heading change angle during helicopter movement are as follows: Figure 7 As shown in (e).

[0089] In this embodiment of the invention, among the physical quantities used to determine wind speed and direction, the ground speed, heading angle, and attitude angle of the strapdown inertial navigation system are highly accurate, while the vacuum speed of the vacuum air compressor is less accurate, and the smaller the vacuum speed, the greater the measurement error. When 0 < atmospheric vacuum speed ≤ 20 km / h, the vacuum speed output by the vacuum air compressor is too low to be considered. In this embodiment of the invention, due to errors in the calculation of the northeast component parameter of wind speed, the eastward wind speed V is calculated separately. WE Northbound wind speed V WN The wind speed V can be obtained by differentiation. W The calculation error equation is expressed as follows:

[0090]

[0091] In formula (5), δψ W Indicates wind speed V W The calculation error, V WN Indicates northward wind speed, δV WE V represents the error in northerly wind speed. WE Indicates eastward wind speed, δV WN This indicates the error in eastward wind speed. In the denominator of formula (5) This represents the square of the wind speed. Under the same measurement error of the wind speed component, the higher the wind speed, the smaller the calculation error of the wind direction; when the wind speed is low, the calculation error of the wind direction will increase sharply.

[0092] The northbound wind speed error δV occurs in the embodiment of this invention. WE Eastward wind speed error δV WN The error is due to wind speed errors caused by helicopters flying backward, sideways, turning, climbing, and descending. Specifically, these errors include: (1) errors in the calculation of the northeast component of the wind speed; (2) the actual longitudinal airspeed of the helicopter in the carrier environment is a valid value, but because a single-axis airspeed cannot measure the rearward airspeed, the overall vacuum speed V obtained in step two is incorrect. t In the middle, the longitudinal airspeed is 0; (3) the forward flight heading of the carrier aircraft and the combined vacuum speed V t The actual directions do not coincide, wind direction Ψ W Real-time calculation; (4) Changes in the forward flight heading of the carrier aircraft, and the overall vacuum speed V t The change in the projected components caused a jump in the wind direction value.

[0093] Furthermore, in the above embodiment of the present invention (4), the projections of the helicopter's ground speed and the combined vacuum speed of the single-axis vacuum engine on the longitudinal axis, transverse axis, and normal axis are subtracted respectively to obtain the three-axis components of the wind speed. The three-axis composite wind speed is then calculated based on the three-axis components, and the wind direction is calculated using the three-axis components of the wind speed. When the helicopter's heading does not coincide with the actual direction of the combined vacuum speed, the wind direction is calculated in real time; however, when the heading of the aircraft changes, the projection component of the combined vacuum speed changes, which in turn causes a jump in the wind direction value. In order to overcome the error and improve the accuracy of wind speed and wind direction, the present invention adjusts the error of wind speed and wind direction through the following step four until the wind speed and wind direction are accurately determined.

[0094] Step 4: Based on the errors in wind speed and direction determined in Step 3, dynamically adjust the heading angle Ψ and the easterly wind speed V. WE Northbound wind speed V WN Re-determine the wind speed and direction until they are accurate.

[0095] Specifically, in step four of the embodiments of the present invention, determining the error in wind speed and wind direction based on step three includes:

[0096] (1) The wind speed V determined in step three W When the wind is relatively small, the wind direction is Ψ W The calculation error increased sharply;

[0097] (2) When the helicopter is flying backward, sideways, turning, climbing, or descending, the wind speed V determined in step three is... W Wind direction Ψ W Simultaneous calculation errors occurred;

[0098] (3) When the helicopter is flying at low speed, during short-duration maneuvering flight, or before resuming high-speed forward flight from maneuvering flight, the wind direction Ψ determined in step three is... W An error occurred.

[0099] Furthermore, in step four of the above embodiments of the present invention, the heading angle Ψ and the easterly wind speed V are dynamically adjusted. WE Northbound wind speed V WN Re-determine wind speed and direction until they are accurately determined, including:

[0100] (1) Determine whether condition 1 is met. If condition 1 is met, cache the helicopter's current heading angle Ψ and eastward speed V every 1 second. E Northbound speed V N 1-second average easterly wind speed V WE and northerly wind speed V WN The maximum buffer time is 30 seconds; substitute the data into formulas (1) and (2) to determine the wind speed and direction.

[0101] Condition 1 is: the helicopter must simultaneously meet the following conditions in a complex scenario: current ground speed > 36 km / h and combined vacuum speed V. t >40km / h, absolute value of (track angle - heading angle Ψ) <45°.

[0102] (2) Starting from when the cached data is full for 30 seconds, check every 1 second whether condition 2 is met. If condition 2 is met, cache the eastward wind speed V for 30 seconds. WE and northerly wind speed V WN After taking the average, record it as and If condition 2 is not met or the cached data in (1) is less than 30s, then the 1s average easterly wind speed V will be used. WE and northerly wind speed V WN Assign to and Will and Substitute into formulas (1) and (2) to determine wind speed and direction.

[0103] Condition 2 is: (a) the maximum cruise speed V of the helicopter within the current 30 seconds. xmax and minimum cruising speed V xmin The absolute value of the difference |ΔV x |≤20km / h; (b) Maximum heading H of the helicopter within the current 30s max Minimum heading H min The absolute value of the difference, |ΔH|, is ≤10°.

[0104] (3) Starting from when the cached data is full for 30 seconds, check every 1 second whether condition 3 is met. If condition 3 is met, cache the eastward wind speed V for 30 seconds. WE and northerly wind speed V WN After taking the average, record the calculation time and the 30-second average. 30-second average Current heading angle Ψ, current combined vacuum velocity V t ;like and Neither of them has been substituted into formulas (1) and (2) for calculation, then like and Since the formulas (1) and (2) have already been substituted into the calculation, then Will and Substitute into formulas (1) and (2) to determine wind speed and direction.

[0105] Condition 3 is: (a) The maximum cruise speed V of the helicopter within the current 30 seconds. xmax and minimum cruising speed V xmin The absolute value of the difference |ΔV x |≤5km / h;(b) The maximum heading H of the helicopter within the current 30s max Minimum heading H min The absolute value of the difference, |ΔH|, is ≤3°;

[0106] (4) Select the current average value of the helicopter. and Substitute into formulas (1) and (2) to determine wind speed and direction; where, and The expression is:

[0107]

[0108] In formula (4), and Obtained through step four (3), and Obtained through step (2) in step four.

[0109] (5) Select the current 30-second average easterly and northerly wind speeds of the helicopter after calibration compensation. and Substitute into formulas (1) and (2) to determine wind speed and direction;

[0110] (6) When condition 4 is met, the wind speed and direction determined by formulas (1) and (2) remain unchanged; where condition 4 is: comprehensive vacuum velocity V t ≤40km / h, or ground speed ≤36km / h, or absolute value of deflection angle >90°.

[0111] It should be noted that in embodiment (3) of the present invention, if conditions (a) and (b) of 3 are satisfied, then the average value of the eastward and northward wind speeds cached for 30 seconds is taken, and the time and 30-second average value are recorded for this calculation. 30s average Current heading angle, attitude array, combined vacuum velocity, and damped altitude. If two records are satisfied, compare the heading angle, time, combined vacuum velocity, and damped altitude recorded after the current conditions are met with the heading angle, time, combined vacuum velocity, and damped altitude recorded after the previous conditions are met. If the following conditions (1)-(4) are met, then calibration calculation is performed; otherwise, only the records are updated, and the calibration matrix is ​​not updated:

[0112] (1) The absolute value of the heading difference (reduced to -180° to 180°) between two consecutive records is greater than 160 degrees;

[0113] (2) The vacuum velocity recorded in both instances was greater than 100 km / h;

[0114] (3) The time interval between the two records is less than 540s;

[0115] (4) The difference in damping height between the two records is less than 200m.

[0116] Specifically, the formula for calculating the calibration matrix is ​​as follows:

[0117]

[0118] In formula (6), For wind speed components recorded in two consecutive intervals, the matrix... sum matrix This is the pose matrix of two consecutive records.

[0119] More specifically, the expression for determining whether the calibration matrix needs to be updated is:

[0120]

[0121] In formula (7), c p This represents the update matrix, where V is the vacuum velocity. t1 and vacuum velocity V t2 This represents the atmospheric vacuum velocity of a single-axis atmospheric engine recorded in two consecutive intervals. Vacuum speed V t1 Vacuum speed V t2 If the unit dimensions remain consistent, then update matrix c. p If |c p (1) |>5° / 57.3 or c p (2) If |>30km / h, then c is not updated. p Matrix c p The initial value is 0, and the value is updated if the above conditions are met.

[0122] Please see Figure 5 and Figure 6 In this embodiment of the invention, flight test data is compared with computational simulation data. Figure 5 The wind direction is shown upwards and the wind speed downwards; the blue line represents test flight data, and the yellow line represents simulation data. According to... Figure 5 As can be seen, the wind speed and direction calculated in the embodiments of the present invention are basically stable and basically consistent with the actual situation. Figure 6The image shows a comparison between flight test data and simulation data of the yaw angle, with the orange line representing flight test data and the blue line representing simulation data. According to... Figure 6 The comparison shows that the deviation angle fluctuation phenomenon obtained in the embodiments of the present invention is basically consistent with the actual situation.

[0123] This invention comprehensively utilizes the eastward speed, northward speed, heading angle of the integrated navigation system, and the vacuum speed of the single-axis atmospheric engine to calculate and determine wind speed and direction, thus solving the problem of inaccurate wind speed and direction calculation and effectively improving the accuracy of wind speed and direction output.

[0124] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A method for determining wind speed and direction in complex helicopter scenarios, characterized in that, The helicopter is equipped with a single-axis air compressor, and the method for determining wind speed and direction includes: Step 1: Extract the helicopter's heading angle Ψ and eastward velocity V based on the inertial navigation system. E and northbound speed V N ; Step 2: Extract the comprehensive vacuum velocity V of the single-axis atmospheric engine based on the inertial navigation system. t ; Step 3: Based on the heading angle Ψ and eastward velocity V E Northbound speed V N and combined vacuum velocity V t Determine the wind speed and direction, specifically: The wind speed is calculated using formula (1), and the expression is: In formula (1), V W V represents wind speed. WE V represents the eastward wind speed. WN Indicates the northward wind speed. Wind speed V represents the square of the wind speed. W The larger the wind direction Ψ W The smaller the calculation error; The wind direction is calculated using formula (2), and the expression is: In formula (2), Ψ W Indicates wind direction, V WE V represents the eastward wind speed. WN This indicates the northerly wind speed; where, if the direction of the incoming wind is defined as the wind direction, then the wind direction Ψ is determined accordingly. W as follows: When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind direction is less than 0, the wind direction is determined as Ψ. W When the easterly wind speed is V WE =0, Northward wind speed V WN When the wind speed is <0, the wind direction is defined as 0°; when the easterly wind speed is V WE >0, northerly wind speed V WN When the wind direction is less than 0, it is determined to be 360° + Ψ. W ; When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind speed is 0, the wind direction is determined to be 90°; when the easterly wind speed is V... WE =0, Northward wind speed V WN When the wind speed is 0, the wind direction is determined to be calm; when the easterly wind speed is V... WE >0, northerly wind speed V WN When the angle is 0, the wind direction is determined to be 270°. When the easterly wind speed is V WE <0, northerly wind speed V WN When the wind direction is greater than 0, the wind direction is determined to be 180° + Ψ. W When the easterly wind speed is V WE =0, Northward wind speed V WN When the wind speed is greater than 0, the wind direction is determined to be 180°; when the easterly wind speed is V... WE >0, northerly wind speed V WN When the wind direction is greater than 0, the wind direction is determined to be 180° + Ψ. W ; Step 4: Dynamically adjust the heading angle Ψ and easterly wind speed V. WE Northbound wind speed V WN Re-determine wind speed and direction until they are accurately determined; including: (1) Determine whether condition 1 is met. If condition 1 is met, cache the helicopter's current heading angle Ψ and eastward speed V every 1 second. E Northbound speed V N 1-second average easterly wind speed V WE and northerly wind speed V WN The maximum buffer time is 30 seconds; substitute the data into formula (1) and formula (2) to determine the wind speed and direction; Among them, condition 1 is: the helicopter simultaneously meets the following conditions in complex scenarios: current ground speed > 36 km / h, comprehensive vacuum speed V t >40km / h, absolute value of (track angle - heading angle Ψ) <45°; (2) Starting from when the cached data is full for 30 seconds, check every 1 second whether condition 2 is met. If condition 2 is met, cache the eastward wind speed V for 30 seconds. WE and northerly wind speed V WN After taking the average value, record it as the eastward wind speed. and northerly wind speed If condition 2 is not met or the cached data is less than 30 seconds, then the 1-second average easterly wind speed V will be used. WE and northerly wind speed V WN Assign a value to the eastward wind speed and northerly wind speed Eastward wind speed and northerly wind speed Substitute into formulas (1) and (2) to determine wind speed and direction; Among them, condition 2 is: (a) the maximum cruise speed V of the helicopter within the current 30s. xmax and minimum cruising speed V xmin The absolute value of the difference |ΔV x |≤20km / h; (b) Maximum heading H of the helicopter within the current 30s max Minimum heading H min The absolute value of the difference, |ΔH|, is ≤10°; (3) Starting from when the cached data is full for 30 seconds, check every 1 second whether condition 3 is met. If condition 3 is met, cache the eastward wind speed V for 30 seconds. WE and northerly wind speed V WN After taking the average value, record the calculation time and the 30-second average easterly wind speed. 30-second average northerly wind speed Current heading angle Ψ, current combined vacuum velocity V t If the easterly wind speed and northerly wind speed Neither of these formulas (1) nor (2) have been substituted into the calculation, so the eastward wind speed is... =Eastward wind speed Northward wind speed =Northward wind speed If the easterly wind speed and northerly wind speed The eastward wind speed has already been calculated using formulas (1) and (2). =Eastward wind speed Northward wind speed = Northbound wind speed Eastward wind speed and northerly wind speed Substitute into formulas (1) and (2) to determine wind speed and direction; Among them, condition 3 is: (a) the maximum cruise speed V of the helicopter within the current 30s. xmax and minimum cruising speed V xmin The absolute value of the difference |ΔV x |≤5km / h;(b) The maximum heading H of the helicopter within the current 30s max Minimum heading H min The absolute value of the difference, |ΔH|, is ≤3°; (4) Select the current average easterly wind speed of the helicopter. and northerly wind speed Substitute into formulas (1) and (2) to determine wind speed and direction; where, easterly wind speed and northerly wind speed The expression is: In formula (4), the eastward wind speed and northerly wind speed The eastward wind speed is obtained through step four (3). and northerly wind speed Obtained through step (2) of the above steps; (5) Select the current 30-second average easterly wind speed and northerly wind speed of the helicopter, and then calibrate and compensate the easterly wind speed. and northerly wind speed Substitute into formulas (1) and (2) to determine wind speed and direction; (6) When condition 4 is met, the wind speed and direction determined by formulas (1) and (2) remain unchanged; wherein, condition 4 is: comprehensive vacuum speed V t ≤40km / h, or ground speed ≤36km / h, or absolute value of deflection angle >90°.

2. The method for determining wind speed and direction in complex helicopter scenarios according to claim 1, characterized in that, Step one includes: Step (11) Obtain the heading angle Ψ of the helicopter through the strapdown inertial navigation system; Step (12) Obtain the ground speed of the helicopter relative to the Earth using the strapdown inertial navigation system, and obtain the eastward speed V of the helicopter based on the ground speed. E and northbound speed V N .

3. The method for determining wind speed and direction in complex helicopter scenarios according to claim 1, characterized in that, Step two includes: Step (21) Obtain the angle of attack α and sideslip angle β of the helicopter through the strapdown inertial navigation system; Step (22) Obtain the composite vacuum velocity V of the single-axis atmospheric engine using a strapdown inertial navigation system. t Among them, the comprehensive vacuum velocity V t It includes the vertical axis velocity component, the horizontal axis velocity component, and the normal velocity component; Step (23) Based on the angle of attack α and sideslip angle β, the combined vacuum velocity V obtained by the single-axis atmospheric engine t The conversion is performed, and the expression is: In formula (3), V represents the wind speed matrix. t ×sin(β) represents the vertical velocity component, V t ×cos(α)×cos(β) represents the velocity component along the horizontal axis, -V t ×sin(α)×cos(β) represents the normal velocity component.

4. The method for determining wind speed and direction in complex helicopter scenarios according to claim 1, characterized in that, Step four involves dynamically adjusting the heading angle Ψ and easterly wind speed V based on the errors in wind speed and direction determined in step three. WE and northerly wind speed V WN .

5. The method for determining wind speed and direction in complex helicopter scenarios according to claim 4, characterized in that, The error in determining wind speed and direction in step three of step four includes: (1) The wind speed V determined in step three W When the wind is relatively small, the wind direction is Ψ W The calculation error increased sharply; (2) When the helicopter is flying backward, sideways, turning, climbing, or descending, the wind speed V determined in step three is... W Wind direction Ψ W Simultaneous calculation errors occurred; (3) Before the helicopter resumes high-speed flight at low speed, during short periods of maneuvering, or before the maneuvering resumes high-speed forward flight, the wind direction Ψ determined in step three. W An error occurred.

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