Airspeed measurement device and method for double-wing unmanned aerial vehicle

Abstract

The present invention provides an airspeed measurement device and a method for measuring the airspeed of a double-wing UAV, wherein the method comprises: S0, determining the current flight stage of the double-wing UAV; S1, determining the airspeed value V obtained by measuring the airspeed value V according to four airspeed meters; i , and the airspeed value V i Solve to the body coordinate system and get the measurement result W i ; S2, according to the measurement results W i Determine the actual wind direction and select the airspeed meter measurement result W in the aircraft coordinate system according to the actual wind direction i As the current wind speed measurement value, the wind speed measurement values in three directions are obtained. S3. The wind speed V in three directions in the body coordinate system x 、V y and V z Perform a Kalman filter to obtain the optimal estimate of the current wind speed, and then determine the horizontal or three-dimensional wind direction. S4. Adjust the attitude of the twin-wing UAV according to the different flight phases and wind direction. This invention improves the flight accuracy and control stability of the twin-wing UAV and reduces the impact of wind speed on the UAV's flight.

Description

Technical Field

[0001] The present invention relates to the field of aviation technology, and in particular to an airspeed measurement device and a measurement method for a double-wing unmanned aerial vehicle. Background Art

[0002] With the development of vertical take-off and landing (VTOL) drones, the requirements for precision in take-off, landing, and stable flight are becoming increasingly stringent. Airspeed is a crucial indicator of a VTOL drone's flight performance. VTOL twin-wing drones require an airspeed measurement device to measure their airspeed. This airspeed data is then fed into the flight controller, which then outputs control commands to ensure stable flight and smooth landing, avoiding stalls. Airspeed measurement devices are essential components for VTOL drones.

[0003] However, most existing vertical take-off and landing double-wing drones use a single airspeed meter installed on the head of the drone. This method cannot obtain all-round airspeed information of the drone, whether it is during vertical take-off and landing or stable flight. This has technical defects and causes large errors in the atmospheric data measured by the airspeed meter, affecting the flight safety of the aircraft. Summary of the Invention

[0004] In light of the above problems, the present invention aims to provide an airspeed measurement device and method for a twin-wing UAV, improving its flight accuracy and control stability while minimizing the impact of wind speed on flight. By adding navigation lights to provide ground operators with real-time information on wind direction and airspeed meter failure, a method for measuring airspeed after an airspeed meter failure is proposed.

[0005] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0006] The present invention provides an airspeed measuring device for a double-wing UAV, comprising: a front wing, a rear wing, a flight controller, a connecting rod, and an airspeed meter device;

[0007] The front wing and the rear wing are connected by two connecting rods. The airspeed meter device includes airspeed meter No. 1, airspeed meter No. 2, airspeed meter No. 3 and airspeed meter No. 4;

[0008] The No. 1 airspeed meter is installed on the left side of the canard through the airspeed meter connector, in the same plane as the wing surface, at an angle of 45° to the vertical direction, with the air inlet facing upwards;

[0009] The No. 2 airspeed meter is installed on the right side of the front wing through the airspeed meter connector, perpendicular to the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing downward;

[0010] The No. 3 airspeed meter is installed on the left side of the rear wing through the airspeed meter connector, perpendicular to the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing downward;

[0011] The No. 4 airspeed meter is installed on the right side of the rear wing through the airspeed meter connector, in the same plane as the wing surface, at a 45° angle to the vertical direction, with the air intake facing upward.

[0012] The flight controller is used to receive the airspeed information from the airspeed meter and issue control commands to the drone.

[0013] Preferably, the airspeed meter connecting member is a U-shaped integral structural member, comprising a fixed end, a first fixed arm and a second fixed arm;

[0014] The fixed end is fixed to the side of the wing with Velcro;

[0015] The first fixed arm and the second fixed arm are respectively provided with asymmetric central holes. The airspeed meter passes through the central holes of the first fixed arm and the second fixed arm in sequence and is fixed.

[0016] The present invention also provides a method for measuring the airspeed of a double-wing UAV, comprising the following steps:

[0017] S0, determine the current flight phase of the dual-wing UAV;

[0018] S1, airspeed value V measured by four airspeed meters i , and the airspeed value V i Solve to the body coordinate system and get the measurement result W i ;

[0019] Where i = 1, 2, 3, 4;

[0020] S2. According to the measurement results W i Determine the actual wind direction and select the airspeed meter measurement result W in the aircraft coordinate system according to the actual wind direction i As the current wind speed measurement value, the wind speed measurement values in three directions are obtained.

[0021] S3, wind speed V in three directions in the body coordinate system x 、V y and V z Perform Kalman filtering to obtain the optimal estimate of the wind speed at the current moment, and then obtain the horizontal wind direction or the three-dimensional wind direction.

[0022] S4. Adjust the posture of the double-wing UAV according to different flight phases of the double-wing UAV and the wind direction obtained in step S3.

[0023] Preferably, the flight phases of the twin-wing UAV include: a vertical take-off and landing phase, a mode switching phase, and a stable flight phase.

[0024] Preferably, the measurement result W i The calculation formula is:

[0025]

[0026]

[0027]

[0028] Among them, α and β are the angle of attack and sideslip angle respectively;

[0029] S aβ is the transformation matrix;

[0030] W wind is the projection of wind speed on the wind axis.

[0031] Preferably,

[0032] In the body coordinate system:

[0033] In the X direction, take the maximum wind speed in the X direction of the No. 1 airspeed meter and the No. 4 airspeed meter as the wind speed measurement value V in the X direction x , the relative position of the airspeed meter corresponding to the maximum wind speed is considered to be the front-to-back wind direction;

[0034] In the Y direction, take the maximum wind speed in the Y direction of the No. 2 airspeed meter and the No. 3 airspeed meter as the wind speed measurement value V in the Y direction y , the relative position of the airspeed meter corresponding to the maximum wind speed is considered to be the wind direction in the Y direction;

[0035] In the Z direction, take the maximum value of the wind speed in the Z direction of the No. 1 airspeed meter and the No. 4 airspeed meter as the wind speed measurement value V in the Z direction z , the relative position of the airspeed meter corresponding to the maximum wind speed is considered to be the wind direction in the Z direction.

[0036] Preferably, in step S3: Kalman filtering includes two stages: prediction and update;

[0037] During the forecasting phase:

[0038] According to the best estimate at the last moment Get the prior estimate of the current moment

[0039]

[0040] in,

[0041] is the prior state estimate at time k;

[0042] is the optimal estimated value of wind speed at time k-1;

[0043] A is the state transfer matrix;

[0044] B is the control matrix;

[0045] U k is the dynamic pressure measured by the airspeed meter device;

[0046] According to the covariance P of the optimal estimate at the previous moment k-1 Get the covariance matrix of the prior estimate at the current moment

[0047]

[0048] in,

[0049] is the prior estimate at time k The prior estimated covariance matrix of ;

[0050] P k-1 is the optimal estimate at time k-1 The covariance matrix of

[0051] Q is the covariance matrix of process noise;

[0052] Get the observation value y at the current moment after correcting the noise k for:

[0053] y k =Cx k +V (7)

[0054] in,

[0055] x k is the measured value at the current moment;

[0056] V is the noise matrix, which obeys the normal distribution;

[0057] C is the measurement coefficient matrix.

[0058] Preferably, in step S3:

[0059] The update phase includes:

[0060] According to the prior estimate covariance matrix at the current moment Get the Kalman gain K k :

[0061]

[0062] in,

[0063] K k is the Kalman filter gain at time k;

[0064] Fusion of the current prior estimate The optimal estimate of the current moment observation value yk is:

[0065]

[0066] in,

[0067] is the optimal estimate at time k;

[0068] is the prior estimate at time k;

[0069] y k is the observation value at time k;

[0070] Preferably, in step S3:

[0071] Finally update the optimal estimate at the current moment The covariance matrix of is used to calculate the prior estimated covariance matrix at the next moment;

[0072]

[0073] in,

[0074] P k is the optimal estimate at the current moment The corresponding covariance matrix.

[0075] Preferably, when one or more airspeed meters fail, the average value of the remaining airspeed meter measurements w is used. wind_average Instead of the projection w of wind speed on the wind axis in the fault-free estimation method wind , proceed to wind speed estimation.

[0076] Compared with the existing technology, the present invention improves the flight accuracy and control stability of the double-wing UAV and minimizes the impact of wind speed on the flight of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1a 3D is a schematic diagram of the three-dimensional structure of a double-wing UAV airspeed measurement device provided according to an embodiment of the present invention.

[0078] Figure 1b 2 is a front view of an airspeed measurement device for a double-wing UAV according to an embodiment of the present invention.

[0079] Figure 1c 2 is a side view of an airspeed measurement device for a double-wing UAV provided according to an embodiment of the present invention.

[0080] Figure 1d 1 is a top view of an airspeed measurement device for a double-wing UAV according to an embodiment of the present invention.

[0081] Figure 2a 3D is a schematic diagram of the three-dimensional structure of an airspeed meter connector provided according to an embodiment of the present invention.

[0082] Figure 2b Schematic diagram of the installation position of the airspeed meter connector provided according to an embodiment of the present invention.

[0083] Figure 2c 4 is a front view of an airspeed meter connecting member provided according to an embodiment of the present invention.

[0084] Figure 2d 4 is a side view of an airspeed meter connector according to an embodiment of the present invention.

[0085] Figure 2e 4 is a top view of an airspeed meter connector according to an embodiment of the present invention.

[0086] Figure 3 The figure is a flow chart of a method for measuring the airspeed of a double-wing UAV provided in accordance with an embodiment of the present invention.

[0087] Figure 4 The figure is a flowchart of a method for measuring the airspeed of a double-wing UAV according to an embodiment of the present invention.

[0088] Figure 5 3 is a schematic diagram of the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when horizontal airflow occurs during the vertical take-off and landing phase.

[0089] Figure 6 3 is a schematic diagram of the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears in front of or above the UAV.

[0090] Figure 7 3 is a schematic diagram of the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears above or below the rear of the UAV.

[0091] Figure 8 3 is a schematic diagram of the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears on the upper left, left side or lower right side of the UAV.

[0092] Figure 9 3 is a schematic diagram of the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears at the lower left, right or upper right of the UAV.

[0093] The reference numerals include: front wing 1, rear wing 2, connecting rod 3, airspeed meter No. 1 41, airspeed meter No. 2 42, airspeed meter No. 3 43, airspeed meter No. 44, airspeed meter connecting piece 45, fixing end 451, first fixing arm 452 and second fixing arm 453. DETAILED DESCRIPTION

[0094] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0095] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0096] Figure 1a A schematic diagram of the three-dimensional structure of an airspeed measurement device for a double-wing UAV provided according to an embodiment of the present invention is shown.

[0097] Figure 1b A front view of an airspeed measurement device for a double-wing UAV provided according to an embodiment of the present invention is shown.

[0098] Figure 1c A side view of an airspeed measurement device for a double-wing UAV provided according to an embodiment of the present invention is shown.

[0099] Figure 1d A top view of an airspeed measurement device for a double-wing UAV provided according to an embodiment of the present invention is shown.

[0100] like Figures 1a-1d As shown, the airspeed measurement device of the double-wing UAV provided in the embodiment of the present invention is a double-wing UAV with vertical take-off and landing, including: a front wing 1, a rear wing 2, a connecting rod 3 and an airspeed meter device.

[0101] The front wing 1 and the rear wing 2 are connected by two connecting rods 3. The airspeed meter device is installed at the end of the double-wing UAV wing. The measurement device provided by the present invention also includes a double-wing UAV flight controller for receiving airspeed information and issuing control commands.

[0102] The airspeed meter device includes a first airspeed meter 41 , a second airspeed meter 42 , a third airspeed meter 43 , a fourth airspeed meter 44 and four airspeed meter connecting pieces 45 .

[0103] Reference Figure 1b :

[0104] The first airspeed meter 41 is mounted on the left side of the canard 1 via the airspeed meter connector 45, in the same plane as the wing surface, at an angle of 45° to the vertical, with the air inlet facing upwards;

[0105] The second airspeed meter 42 is mounted on the right side of the front wing 1 through the airspeed meter connector 45, perpendicular to the wing surface, at an angle of 45° to the vertical direction, with the air inlet facing downwards;

[0106] The third airspeed meter 43 is mounted on the left side of the rear wing 2 via an airspeed meter connector 45, perpendicular to the wing surface, at an angle of 45° to the vertical, with the air inlet facing downwards;

[0107] The fourth airspeed meter 44 is installed on the right side of the rear wing 2 through the airspeed meter connector 45, in the same plane as the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing upward.

[0108] The No. 1 airspeed meter and the No. 4 airspeed meter work during the stable level flight phase of the twin-wing UAV.

[0109] The No. 2 airspeed meter and the No. 3 airspeed meter work during the vertical take-off and landing phase of the twin-wing UAV.

[0110] When switching between rotor and fixed-wing modes, the twin-wing drone is in a tilted posture, and all four airspeed meters work to ensure that they can provide three-dimensional ambient wind speed and direction during the conversion process.

[0111] Figure 2a A schematic diagram of the three-dimensional structure of an airspeed meter connecting piece provided according to an embodiment of the present invention is shown.

[0112] Figure 2b A schematic diagram of the installation position of an airspeed meter connector provided according to an embodiment of the present invention is shown.

[0113] Figure 2c A front view of an airspeed meter connecting member provided according to an embodiment of the present invention is shown.

[0114] Figure 2d A side view of an airspeed meter connection member provided according to an embodiment of the present invention is shown.

[0115] Figure 2e A top view of an airspeed meter connecting member provided according to an embodiment of the present invention is shown.

[0116] like Figures 2a-2e As shown, the airspeed meter connecting member 45 provided in the embodiment of the present invention is a U-shaped integral structural member, including a fixed end 451, a first fixed arm 452 and a second fixed arm 453;

[0117] The fixed end 451 is adhered and fixed to the side of the wing by Velcro.

[0118] The first fixing arm 452 and the second fixing arm 453 are respectively provided with asymmetric center holes. The airspeed meter passes through the center holes of the first fixing arm 452 and the second fixing arm 453 in sequence and is fixed by glue or Velcro so that there is no relative movement between the airspeed meter and the airspeed meter connector 45.

[0119] When the airspeed meter is fixed by Velcro, one side of the Velcro wraps around the airspeed meter and is adhered, and the other side is adhered to the inside of the center hole.

[0120] Figure 3 The figure shows a flow chart of a method for measuring the airspeed of a double-wing UAV provided in accordance with an embodiment of the present invention.

[0121] Figure 4 A flowchart of an airspeed measurement method for a double-wing UAV provided in accordance with an embodiment of the present invention is shown.

[0122] The airspeed measurement method of a dual-wing UAV provided in an embodiment of the present invention includes the following steps:

[0123] S0. Determine the current flight phase of the dual-wing UAV.

[0124] The flight phases of the twin-wing UAV include: vertical take-off and landing phase, mode switching phase and stable flight phase.

[0125] S1, airspeed value V measured by four airspeed meters i , and the airspeed value V i Solve to the body coordinate system and get the measurement result W i .

[0126] Among them, i=1, 2, 3, 4.

[0127] In a stationary atmosphere, the speed of the double-wing drone relative to the air is equal to the speed of the double-wing drone relative to the earth.

[0128] In a non-stationary atmosphere, the ground speed is equal to the vector sum of the air speed and the wind speed. The magnitude and direction of the ground speed can be measured by the GPS of the double-wing UAV. The direction of the ground speed is the direction of the double-wing UAV's track.

[0129]

[0130] in, is the ground speed; is the airspeed; is the wind speed:

[0131] Measurement results W i The calculation formula is:

[0132]

[0133] The airspeed V measured by each airspeed meter i (i=1, 2, 3, 4) Solving the machine system requires solving the conversion matrix composed of the sideslip angle α and the angle of attack β. α and β are the angle of attack and the sideslip angle, respectively. The conversion matrix S αβ for:

[0134]

[0135]

[0136] Among them, α and β are the angle of attack and sideslip angle respectively;

[0137] S αβ is the transformation matrix;

[0138] W wind is the projection of wind speed on the wind axis.

[0139] S2. According to the measurement results W i Determine the actual wind direction and select the airspeed meter measurement result W in the aircraft coordinate system according to the actual wind direction i As the current wind speed measurement value, the wind speed measurement values in three directions are obtained.

[0140] According to the measurement results of four airspeed meters W i Determine wind direction.

[0141] In the body coordinate system:

[0142] In the X direction, take the maximum wind speed in the X direction of the No. 1 and No. 4 airspeed gauges as the wind speed measurement value V in the X direction x , the relative position of the airspeed gauge corresponding to the large airspeed value is considered to be the front and rear wind direction;

[0143] In the Y direction, take the maximum wind speed in the Y direction of the No. 2 and No. 3 airspeed meters as the wind speed measurement value V in the Y direction y , the relative position of the airspeed meter corresponding to the larger airspeed value is considered to be the wind direction in the Y direction;

[0144] In the Z direction, take the maximum wind speed in the Z direction of the No. 1 and No. 4 airspeed meters as the wind speed measurement value V in the Z direction z The relative position of the airspeed meter corresponding to the larger airspeed value is considered to be the wind direction in the Z direction.

[0145] When the aircraft is in remote control mode, the ground operator needs to adjust the aircraft attitude by remote control. In order to facilitate the ground operator to quickly grasp the high-altitude wind direction, navigation lights are added to indicate the wind direction in real time to the ground personnel and which airspeed meter measurement value is currently used to estimate the wind speed.

[0146] Four of the navigation lights are attached to the sides of the airspeed gauges. They are powered by the drone's battery and connected to the flight controller. When the airspeed gauges are used to estimate wind speed, the flight controller issues a command to make the lights flash green. When the airspeed gauges are not being used, the lights remain off.

[0147] When sandstorms occur, the air intake of the above airspeed meter will be blocked, causing the airspeed meter to malfunction. When one or more airspeed meters fail, the average value of the remaining airspeed meter measurements w is used. wind_average Instead of the projection w of wind speed on the wind axis in the fault-free estimation method wind , continue to estimate the wind speed. At this time, the navigation light on the side of the airspeed meter, which is used to estimate the airspeed, flashes red.

[0148] If the No. 2 airspeed sensor fails:

[0149] but

[0150] Among them, V x1 , V y1 , V z1 are the airspeeds of No. 1 airspeed meter in the x, y, and z directions respectively; V x3 , V y3 , V z3 are the airspeeds of No. 3 airspeed gauge in the x, y, and z directions respectively; V x4 , V y4 , V z4 They are the airspeeds of No. 4 airspeed meter in the x, y, and z directions respectively.

[0151] S3, wind speed V in three directions in the body coordinate system x 、V y and V z Kalman filtering is performed separately to obtain the optimal estimated value of the wind speed at the current moment, and then the horizontal wind direction or the three-dimensional wind direction is obtained.

[0152] Kalman filtering includes two stages: prediction and update, which requires the wind speed measurement value at the current moment and the optimal estimate of the wind speed at the previous moment.

[0153] The optimal estimated value of wind speed at the previous moment is used to predict the current value as the prior estimate, and the prior estimate is fused with the observed value to obtain the optimal estimate at the current moment.

[0154] The wind speed V in each direction of the body coordinate system x 、V y and V z As the actual measured value x k The weight.

[0155] The forecasting phase includes:

[0156] The prior estimate of the current moment is obtained based on the optimal estimate of the previous moment:

[0157]

[0158] in,

[0159] is the prior state estimate at time k;

[0160] is the optimal estimated value of wind speed at time k-1;

[0161] A is the state transfer matrix; the dual-wing UAV aircraft environment characteristic parameters are used as the system state matrix A, and the UAV track environment characteristic parameters include the UAV ground speed and the UAV attitude.

[0162] B is the control matrix;

[0163] U k is the dynamic pressure measured by the airspeed meter.

[0164] It can be seen from the above formula that based on the optimal estimate at the previous moment, the prior estimate at moment k can be obtained, but it is not the final result at moment k.

[0165] The covariance matrix of the prior estimate at the current moment is obtained based on the covariance of the optimal estimate at the previous moment:

[0166]

[0167] in,

[0168] is the prior estimate at time k The prior estimated covariance matrix of ;

[0169] P k-1 is the optimal estimate at time k-1 The covariance matrix of :

[0170] Q is the covariance matrix of the process noise, which obeys the normal distribution and is used to calculate the Kalman gain K in the update phase. k ;

[0171] Get the observation value y at the current moment after correcting the noise k for:

[0172] y k =Cx k +V (7)

[0173] in,

[0174] x kis the measured value at the current moment;

[0175] V is the noise matrix, which obeys the normal distribution;

[0176] C is the measurement coefficient matrix.

[0177] The update phase includes:

[0178] According to the prior estimate covariance matrix at the current moment Get the Kalman gain K k :

[0179]

[0180] in,

[0181] K k is the Kalman filter gain at time k, which is the observation value y k and weighting coefficients of the a priori estimates;

[0182] Fusion of the current prior estimate Current observation value y k The optimal estimate at the current moment is:

[0183]

[0184] in,

[0185] is the optimal estimate at time k, which is composed of the weighted sum of the prior estimate at the current moment and the observation value at the current moment;

[0186] is the prior estimate at time k;

[0187] y k is the observation value at time k;

[0188] Finally update the optimal estimate at the current moment The covariance matrix of :

[0189]

[0190] in,

[0191] P k is the optimal estimate at the current moment The corresponding covariance matrix is used to calculate the prior estimated covariance matrix at the next moment.

[0192] In Kalman filtering, the k-time prediction part is the basis of the k-time update part, and the k-time update is the basis of the k+1-time prediction. By continuously updating the iterative Kalman gain K k , optimal estimate at time k Covariance matrix P k , get the airspeed information of the UAV’s current environment.

[0193] S4. Adjust the posture of the double-wing UAV according to different flight phases of the double-wing UAV and the wind direction obtained in step S3.

[0194] The maximum and minimum windward attitudes of the aircraft in different planes can be obtained through the wind speed in three directions of the body coordinate system to adapt to different flight phases, including vertical take-off and landing phase, rotor mode and fixed-wing mode switching phase, and stable flight phase.

[0195] Figure 5 A schematic diagram shows the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when horizontal airflow occurs during the vertical take-off and landing phase.

[0196] Figure 6 A schematic diagram shows the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears in front of or above the UAV.

[0197] Figure 7 A schematic diagram shows the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears above or below the rear of the UAV.

[0198] Figure 8 A schematic diagram shows the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears on the upper left, left side or lower right of the UAV.

[0199] Figure 9 A schematic diagram shows the posture of the double-wing UAV airspeed measurement device provided by an embodiment of the present invention when airflow appears at the lower left, right or upper right of the UAV.

[0200] like Figure 5-9 As shown:

[0201] During vertical takeoff and landing (VTOL), the twin-wing drone uses a stereoscopic measurement device to measure the airspeed in the horizontal plane at the current altitude. This calculation yields the airspeed in all directions within the aircraft's coordinate system. The airspeed in each direction is then filtered through a Kalman filter to obtain an estimated airspeed value, which allows the wind direction on the horizontal plane to be determined. The minimum windward attitude is calculated based on the wind speed, and the drone's wing surface is aligned with the wind direction. Before the drone's attitude deviates, the flight controller outputs control commands to adjust its attitude, reducing the windward area or compensating for the wind's effects on the drone, thus preventing stall. This shows that during vertical landing, the drone still needs to utilize a stereoscopic airspeed measurement device to obtain airspeed measurements in all directions. This is then filtered through a Kalman filter to obtain the true airspeed value, allowing for pre-adjusted attitude or compensation for the effects of wind speed on the drone. This reduces interference with the drone and ensures stability during vertical takeoff.

[0202] During the mode switch phase, from rotor to fixed wing, the twin-wing drone's wings need to shift from vertical to horizontal, and the propellers change speed to adjust lift, achieving attitude adjustment and mode switching. This transition is powered entirely by the drone's energy storage battery. A three-dimensional airspeed measurement device is used to measure wind speed in all directions to determine wind direction. The measured values are then filtered through a Kalman filter to determine the true airspeed. While ensuring stability, the direction with the highest wind speed is selected. Using the combined effects of wind and electrical energy, the drone's attitude is adjusted, aligning the wings perpendicular to the horizontal wind direction. This maximizes the use of ambient wind energy during the mode switch and minimizes battery drain.

[0203] The three-dimensional airspeed measurement device of the biplane UAV can continuously provide airspeed information to the UAV flight controller during the switching process, calculate the environmental three-dimensional airspeed during the flight, and adjust the wing surface of the biplane UAV to be perpendicular to the three-dimensional wind direction while ensuring stability, thereby increasing the influence of wind speed on the UAV mode switching process, so as to maximize the use of wind energy and reduce the consumption of energy storage batteries.

[0204] During the stable flight phase, to increase cruising time and reduce energy consumption, the drone's ambient wind speed and direction are measured, continuously acquiring the current airspeed. The drone's flight controller then calculates the attitude that maximizes wind energy utilization. Based on wind speed fluctuations, the drone's attitude is continuously adjusted, ensuring that the drone is constantly operating in a state where wind and electrical energy are acting in concert. Ultimately, the drone maintains stable flight along its route, minimizing wind impact.

[0205] The three-dimensional airspeed measurement device obtains the environmental airspeed information of the double-wing UAV in real time, fully grasps the atmospheric information around the double-wing UAV, and helps the double-wing UAV flight controller to make accurate judgments in time, issue control commands, and adjust the attitude of the double-wing UAV, so as to stay away from wind interference, avoid stall, and save energy.

[0206] When a horizontal airflow appears in front of the twin-wing drone, the rudders are swung downward, using the wind to increase the altitude and converting wind energy into gravitational potential energy.

[0207] When horizontal airflow appears on the left side of the twin-wing drone, it tilts to the right and uses the wind to increase its altitude.

[0208] When downward airflow appears on the left side of the twin-wing drone, it tilts to the right to reduce the area affected by the wind.

[0209] When airflow in other directions occurs, the attitude of the twin-wing drone should be adjusted as follows: Figure 6-Figure 9 shown.

[0210] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0211] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for measuring the airspeed of a twin-wing UAV, characterized in that: The airspeed measurement device of the double-wing UAV is used to measure the airspeed of the double-wing UAV. The double-wing UAV airspeed measurement device includes: a front wing, a rear wing, a flight controller, a connecting rod and an airspeed meter device; The front wing and the rear wing are connected by two connecting rods, and the airspeed meter device includes a first airspeed meter, a second airspeed meter, a third airspeed meter and a fourth airspeed meter; The No. 1 airspeed meter is installed on the left side of the canard through the airspeed meter connector, in the same plane as the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing upwards; The second airspeed meter is installed on the right side of the front wing through the airspeed meter connector, perpendicular to the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing downward; The No. 3 airspeed meter is installed on the left side of the rear wing through the airspeed meter connector, perpendicular to the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing downwards; The No. 4 airspeed meter is installed on the right side of the rear wing through the airspeed meter connector, in the same plane as the wing surface, at an angle of 45 degrees to the vertical direction, with the air inlet facing upwards; The flight controller is used to receive the airspeed information from the airspeed meter and issue control instructions to the UAV; The airspeed measurement method includes the following steps: S0, determine the current flight phase of the dual-wing UAV; S1, airspeed value V measured by four airspeed meters i , and the airspeed value V i Solve to the body coordinate system and get the measurement result W i ; Where i = 1, 2, 3, 4; S2, according to the measurement result W i Determine the actual wind direction and select the airspeed meter measurement result W in the aircraft coordinate system according to the actual wind direction i As the current wind speed measurement value, the wind speed measurement values in three directions are obtained; S3, wind speed V in three directions in the body coordinate system x 、V y and V z Perform Kalman filtering to obtain the optimal estimate of the wind speed at the current moment, and then obtain the horizontal wind direction or the three-dimensional wind direction; S4. Adjust the posture of the double-wing UAV according to different flight phases of the double-wing UAV and the wind direction obtained in step S3.

2. The airspeed measurement method of a double-wing UAV according to claim 1, characterized in that: The airspeed meter connecting member is a U-shaped integral structural member, comprising a fixed end, a first fixed arm and a second fixed arm; The fixed end is fixed to the side of the wing by means of Velcro; The first fixed arm and the second fixed arm are respectively provided with an asymmetric central hole, and the airspeed meter passes through the central holes of the first fixed arm and the second fixed arm in sequence, and the airspeed meter is fixed.

3. The airspeed measurement method of a double-wing UAV according to claim 1, characterized in that: The flight phases of the dual-wing UAV include: a vertical take-off and landing phase, a mode switching phase, and a stable flight phase.

4. The method for measuring airspeed of a double-wing UAV according to claim 3, characterized in that: The measurement result W i The calculation formula is: Among them, α and β are the angle of attack and sideslip angle respectively; S αβ is the transformation matrix; W wind is the projection of wind speed on the wind axis.

5. The method for measuring airspeed of a double-wing UAV according to claim 4, characterized in that: In the body coordinate system: In the X direction, the maximum wind speed of the No. 1 airspeed meter and the No. 4 airspeed meter in the X direction is taken as the wind speed measurement value V in the X direction. x , the relative position of the airspeed meter corresponding to the maximum wind speed is considered to be the front-to-back wind direction; In the Y direction, the maximum wind speed of the No. 2 airspeed meter and the No. 3 airspeed meter in the Y direction is taken as the wind speed measurement value V in the Y direction. y , the relative position of the airspeed meter corresponding to the maximum wind speed is considered to be the wind direction in the Y direction; In the Z direction, the maximum wind speed of the No. 1 airspeed meter and the No. 4 airspeed meter in the Z direction is taken as the wind speed measurement value V in the Z direction. z , the relative position of the airspeed meter corresponding to the maximum wind speed is considered to be the wind direction in the Z direction.

6. The method for measuring airspeed of a double-wing UAV according to claim 5, characterized in that: In step S3: Kalman filtering includes two stages: prediction and update; During the forecasting phase: According to the best estimate at the last moment Get the prior estimate of the current moment in, is the prior state estimate at time k; is the optimal estimated value of wind speed at time k-1; A is the state transfer matrix; B is the control matrix; U k is the dynamic pressure measured by the airspeed meter device; According to the covariance P of the optimal estimate at the previous moment k-1 Get the covariance matrix of the prior estimate at the current moment in, is the prior estimate at time k The prior estimated covariance matrix of ; P k-1 is the optimal estimate at time k-1 The covariance matrix of Q is the covariance matrix of process noise; Get the observation value y at the current moment after correcting the noise k for: y k =Cx k +V (7) in, x k is the measured value at the current moment; V is the noise matrix, which obeys the normal distribution; C is the measurement coefficient matrix.

7. The method for measuring airspeed of a double-wing UAV according to claim 6, characterized in that: In step S3: The update phase includes: According to the prior estimate covariance matrix at the current moment Get the Kalman gain K k : in, K k is the Kalman filter gain at time k; Fusion of the current prior estimate Current observation value y k The optimal estimate at the current moment is: in, is the optimal estimate at time k; is the prior estimate at time k; y k is the observation value at time k.

8. The method for measuring airspeed of a double-wing UAV according to claim 7, characterized in that: In step S3: Finally update the optimal estimate at the current moment The covariance matrix of is used to calculate the prior estimated covariance matrix at the next moment; in, P k is the optimal estimate at the current moment The corresponding covariance matrix.

9. The method for measuring airspeed of a double-wing UAV according to claim 8, characterized in that: When one or more airspeed meters fail, use the average value of the remaining airspeed meter measurements, w wind_average Instead of the projection w of wind speed on the wind axis in the fault-free estimation method wind , proceed to wind speed estimation.

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