Wing deployment timing control method for Π-type folding-wing UAV

Abstract

The present invention proposes a wing deployment timing control method for a Π-type folding wing UAV, which unlocks and deploys the outer wings on both sides in time, and uses the wing on one side that rotates backward to first open the outer wing, thereby generating a rolling restoring torque to balance the rolling torque generated by the difference in incoming flow speed on the wing surfaces on both sides in the initial stage of main wing deployment; and the present invention also determines the time difference t of the time-sharing unlocking of the outer wings on both sides, with the main wing deployed to the vertical fuselage, and the UAV roll angle is 0° as the final goal, and the time difference t is obtained by iterative calculation. The actual test flight results show that the control method solves the problem that the attitude of the Π-type folding wing UAV has a large deviation after leaving the tube and the attitude is difficult to recover, and realizes the stable flight of the Π-type folding wing UAV.

Description

Technical Field

[0001] The present invention relates to the technical field of folding-wing UAV control, and in particular to a wing deployment timing control method for a Π-type folding-wing UAV. Background Art

[0002] The canister-launched folding-wing UAV is an advanced aircraft that combines folding technology and UAV technology. Its characteristic is that the wings and tail can be folded, which greatly improves the portability and rapid deployment capability.

[0003] For large aspect ratio folding wing drones, the wings are divided into the main wing and the outer wings at both ends of the main wing. The middle part of the main wing is connected to the fuselage by rotation. The main wing can rotate around the axis of rotation and switch between the storage state parallel to the fuselage and the unfolded state perpendicular to the fuselage. The unfolding method of the outer wing relative to the main wing mainly adopts the outer wing unfolding method disclosed in the Chinese patent with publication number CN116729657A. The movement plane of the outer wing during the unfolding process is parallel to the movement plane of the main wing during the unfolding process. However, this unfolding method causes a height difference between the main wing and the outer wing after the outer wing is unfolded, which in turn causes wing circulation loss and affects the lift-to-drag ratio.

[0004] To solve the above problem, the outer wing deployment method can be adjusted to make the movement plane of the outer wing during the deployment process perpendicular to the movement plane of the main wing during the deployment process. In this way, the outer wing can be connected with the end surface of the main wing after deployment to form a complete wing. Since the wing is roughly Π-shaped during the rotation of the outer wing relative to the main wing, it is called a Π-type folding wing. Summary of the invention

[0005] Technical issues to be solved:

[0006] In order to simplify the control as much as possible and reduce the cost, the outer wing of the barrel-launched Π-type folding-wing UAV is in the folded state, and the outer wing is between the main wing and the fuselage, and the fuselage provides a limit constraint, while the main wing provides a limit constraint through the barrel wall; when the UAV is launched from the tube, the barrel wall constraint is eliminated, and the main wing is driven to unfold by the rotating drive mechanism connected to the fuselage in the middle; during the main wing unfolding process, the fuselage's constraint on the outer wing is released as the main wing unfolds to a certain angle, and at this time the outer wing is driven to unfold by the rotating drive mechanism connected to the outer end of the main wing at its inner end. However, the applicant found during the test flight that, using the above-mentioned unfolding control method, a large rolling moment will appear after the Π-type folding-wing UAV comes out of the barrel. At this time, since the wing has not yet been fully unfolded, the control efficiency of the control surfaces such as the aileron in the rolling direction has not yet been exerted, and it is difficult to provide a restoring moment, resulting in the UAV often losing control and crashing due to a large roll after coming out of the barrel.

[0007] In response to the above problems, the applicant carefully analyzed the reasons why the UAV had a large rolling moment after leaving the tube:

[0008] First, since the rear part of the drone fuselage adopts a retractable design, when the outer wing is only constrained by the fuselage, the outer wing that is on the upper side of the rear fuselage and moves forward with the main wing is released earlier than the outer wing that is on the upper side of the front fuselage and moves backward with the main wing.

[0009] Secondly, when the outer wing is in a folded state, the airfoil formed by the outer wing and the main wing is approximately a symmetrical airfoil. When one side of the outer wing is released first, the airfoil of the main wing on the same side is converted into a high-lift airfoil, generating a lift greater than that of the other side wing, resulting in an imbalance of aerodynamic forces on both sides, and thus a larger rolling moment.

[0010] In response to this phenomenon, the applicant considered adjusting the restraint method of the outer wing, changing the original restraint method provided by the fuselage to a locking mechanism between the outer wing and the main wing, providing outer wing restraint through the locking mechanism, and releasing the outer wings on both sides simultaneously when the main wing rotates to a state vertical to the fuselage, in order to avoid generating a large rolling moment during the deployment of the outer wing.

[0011] However, the applicant found through further research that the control method of synchronously releasing the outer wings on both sides when the main wing rotates to a state vertical to the fuselage is not the optimal control method to achieve aerodynamic performance and control performance. The specific analysis is as follows: During the main wing rotation and deployment, the wing at the rear of the fuselage rotates forward, and the wing at the front of the fuselage rotates backward. The flow velocity on the wing surface is formed by the superposition of its rotation speed and the free flow speed vector. Since the launch speed of the drone is not large when it leaves the tube, that is, the free flow speed is not much greater than the rotation speed, the rotation speed cannot be ignored when calculating the flow velocity on the wing surface, resulting in the flow velocity on the wing surface of the wing rotating backward at the front of the fuselage being significantly smaller than the flow velocity on the wing surface of the wing rotating forward, which in turn causes the lift of the wing rotating backward to be significantly smaller than the lift of the wing rotating forward, which still leads to an imbalance of aerodynamic forces on both sides, so that rolling torque still occurs during the deployment of the main wing.

[0012] Since there is no control rudder to balance the above-mentioned rolling moment during the main wing deployment, the applicant considers that by controlling the deployment time difference of the outer wings on both sides, the outer wing on the side of the main wing that rotates backwards is deployed first, so that the airfoil of the wing part on this side is first converted into a high-lift airfoil, which can generate greater lift than the approximately upper and lower symmetrical airfoil of the wing on the other side, thereby providing a rolling restoring moment, so that the UAV is in a balanced state when the main wing and the outer wing are fully deployed. For this reason, the present invention proposes a wing deployment timing control method for a Π-type folding wing UAV.

[0013] The technical solution of the present invention is:

[0014] The present invention discloses a method for controlling the unfolding timing of the wings of a Π-type folding-wing UAV, wherein the wings of the folding-wing UAV are divided into a main wing and outer wings located at both ends of the main wing; the middle part of the main wing is connected to the upper part of the fuselage by a rotational manner, and the main wing can be unfolded under the drive of the main wing rotation drive mechanism, and locked when the main wing is rotated to be perpendicular to the fuselage; the inner ends of the outer wings on both sides are respectively connected to the end of one side of the main wing by a rotational manner, and locking mechanisms are respectively provided between the outer wings on both sides and the main wing, and when locked, the outer wings are folded under the main wings; when the locking mechanisms are controlled to be unlocked, and the fuselage has no constraints on the outer wings, the outer wings can be unfolded under the drive of the outer wing rotation drive mechanism, and the motion plane of the outer wing unfolding process is perpendicular to the motion plane of the main wing unfolding process;

[0015] The timing control method is: by controlling the two locking mechanisms between the outer wing and the main wing to unlock in time, the outer wing at the rear of the fuselage is unlocked when the main wing rotates to be perpendicular to the fuselage, and the outer wing at the front of the fuselage is unlocked before the outer wing at the rear of the fuselage by t time;

[0016] The duration t is obtained by the following process:

[0017] Step 1: Determine the time T required for the main wing to rotate from unlocking to perpendicular to the fuselage, and set the initial value of t 初始 ; Determine the linear velocity of each section of the wing during the rotation of the main wing, and combine the launch speed of the Π-shaped folding wing UAV to calculate the incoming flow velocity of each section of the wing at each moment during the process from the main wing being unlocked to rotating to a state perpendicular to the fuselage;

[0018] Step 2: Establish a first simplified three-dimensional model and a second simplified three-dimensional model of the wing, wherein the first simplified three-dimensional model is a wing model in which both outer wings on both sides are in a locked state with the main wing; the second simplified three-dimensional model is a wing model in which the outer wings of one wing rotating backward are fully unfolded, and the outer wings of the one wing rotating forward are kept in a locked state with the main wing;

[0019] Step 3: Using the first simplified three-dimensional model and the incoming flow velocities of each wing section obtained in step 1, with the main wing unlocked as time 0, simulate and calculate the force of the first simplified three-dimensional model in the time period Tt, and obtain the rolling angle θ1 of the first simplified three-dimensional model around the longitudinal axis of the Π-type folding wing UAV at time Tt;

[0020] Step 4: Using the second simplified three-dimensional model and the incoming flow velocity of each cross section of the wing obtained in step 1, the second simplified three-dimensional model is in a rolling angle state of θ1 as 0, and the force of the second simplified three-dimensional model in a time period t is simulated and calculated to obtain the rolling angle θ2 of the second simplified three-dimensional model around the longitudinal axis of the Π-type folding wing UAV at time t;

[0021] Step 5: If the roll angle θ2 is 0°, the t value is obtained; otherwise, the t value is adjusted according to the value of the roll angle θ2, and steps 3 and 4 are repeated until the roll angle θ2 is 0°.

[0022] Furthermore, in step 1, the time T required for the main wing to rotate from unlocking to a state perpendicular to the fuselage is determined according to the rotational angular velocity of the main wing after unlocking.

[0023] Furthermore, in step 1, the linear velocity of each section of the wing during the main wing rotation process is determined according to the rotation angular velocity after the main wing is unlocked.

[0024] Beneficial effects:

[0025] Aiming at the problem that a large rolling moment occurs in a barrel-launched Π-type folding-wing UAV after it leaves the barrel, resulting in a large deviation in the rolling attitude of the UAV, and the attitude is difficult to recover due to the lack of control rudder effect, the present invention deeply analyzes the cause of the phenomenon, and finally determines that the outer wings on both sides are unlocked and unfolded in time, and the outer wing on one side rotating backward is used to open the outer wing first, thereby generating a rolling restoring moment to balance the rolling moment generated by the difference in incoming flow speed on the wing surfaces on both sides in the initial stage of main wing unfolding; and the present invention proposes a method for determining the time difference t of the time-sharing unlocking of the outer wings on both sides, and takes the moment when the main wing is unfolded to be vertical to the fuselage and the UAV roll angle is 0° as the final goal, and iteratively calculates the time difference t.

[0026] The actual test flight results show that the control method can solve the problem of large deviation in the posture of the Π-type folding-wing UAV after it leaves the tube and the difficulty in restoring the posture, and realize the stable flight of the Π-type folding-wing UAV.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 : Schematic diagram of the barrel-launched Π-type folding-wing UAV; (folded state)

[0030] Figure 2 : Schematic diagram of the barrel-launched Π-type folding-wing UAV (fully deployed)

[0031] Figure 3 : Schematic diagram of the wing cross section when the outer wing is in the locked state;

[0032] Figure 4 : Schematic diagram of the main wing cross section after the outer wing is unlocked and unfolded;

[0033] Figure 5 : Schematic diagram of the first simplified three-dimensional model;

[0034] Figure 6 : Schematic diagram of the second simplified three-dimensional model;

[0035] Figure 7 : Schematic diagram of the unfolding process of the Π-type folding wings of the barrel launch. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] like Figure 1 and Figure 2As shown, the barrel-launched Π-type folding-wing UAV targeted by the present invention adopts a large aspect ratio upper single-wing layout; the fuselage body is a square cross-section, and the rear part of the fuselage adopts a retractable design; the wing is divided into a main wing and an outer wing located at both ends of the main wing, and the middle part of the main wing is connected to the fuselage by a rotational manner, and the main wing can be unfolded under the drive of the main wing rotation drive mechanism, and locked when the main wing is rotated to be perpendicular to the fuselage; due to the large aspect ratio design requirements, the length of the main wing is close to the overall length of the fuselage; the inner ends of the outer wings on both sides are respectively connected to the end of one side of the main wing by a rotational manner, and locking mechanisms are respectively provided between the outer wings on both sides and the main wing, and when locked, the outer wings are folded under the main wings; when the locking mechanism is controlled to be unlocked, and the fuselage has no constraints on the outer wings, the outer wings can be unfolded under the drive of the outer wing rotation drive mechanism, and after being unfolded in place, they are locked with the main wings again to form an integrated wing, and the movement plane of the outer wing during the unfolding process is perpendicular to the movement plane of the main wing during the unfolding process.

[0040] In the initial deployment control design, in order to make the control as simple as possible and reduce costs, the outer wing of the barrel-launched Π-type folding-wing UAV is located between the main wing and the fuselage in the folded state, and the fuselage provides a limit constraint, while the main wing provides a limit constraint through the barrel wall; when the UAV is launched from the tube, the barrel wall constraint is eliminated, and the main wing is driven to deploy by the main wing rotation drive mechanism connected to the fuselage in the middle; during the main wing deployment process, the constraint of the fuselage on the outer wing is released after the main wing is deployed to a certain angle, and at this time the outer wing is driven to deploy by the outer wing rotation drive mechanism whose inner end is connected to the outer end of the main wing.

[0041] However, during the test flight, it was found that when using the above-mentioned deployment control method, the Π-type folding-wing UAV will experience a large rolling moment after leaving the tube. At this time, since the wings have not yet been fully unfolded, the control efficiency of the ailerons and other control surfaces in the rolling direction has not yet been exerted, and it is difficult to provide a restoring moment. As a result, the UAV often loses control and crashes due to a large roll after leaving the tube.

[0042] In response to the above problems, we carefully analyzed the reasons why the drone has a large rolling moment after leaving the tube:

[0043] First, since the rear part of the drone fuselage adopts a retractable design, when the outer wing is only constrained by the fuselage, the outer wing on the upper side of the rear fuselage and moving forward with the main wing is released earlier than the outer wing on the upper side of the front fuselage and moving backward with the main wing.

[0044] Secondly, when the outer wing is in the folded state, the airfoil formed by the outer wing and the main wing is approximately a vertically symmetrical airfoil, such as Figure 1 and Figure 3 As shown in the figure; when one side of the outer wing is released first, the airfoil of the main wing on the same side is converted into a high-lift airfoil, as shown in the figure. Figure 4 As shown, the lift generated on one wing is greater than that on the other wing, resulting in an imbalance in the aerodynamic forces on both sides, resulting in a larger rolling moment.

[0045] In response to this phenomenon, the applicant considered adjusting the restraint method of the outer wing, changing the original restraint method provided by the fuselage to a locking mechanism between the outer wing and the main wing, providing outer wing restraint through the locking mechanism, and releasing the outer wings on both sides simultaneously when the main wing rotates to a state vertical to the fuselage, in order to avoid generating a large rolling moment during the deployment of the outer wing.

[0046] However, further research has found that the control method of releasing the outer wings on both sides simultaneously when the main wing rotates to a state vertical to the fuselage is not the optimal control method to achieve aerodynamic performance and control performance. The specific analysis is as follows: During the main wing rotation and deployment, the wing at the rear of the fuselage rotates forward, and the wing at the front of the fuselage rotates backward. The flow velocity on the wing surface is the superposition of its rotation speed and the free flow speed vector. Since the launch speed of the drone is not large when it leaves the tube, that is, the free flow speed is not much greater than the rotation speed, the rotation speed cannot be ignored when calculating the flow velocity on the wing surface, resulting in the flow velocity on the wing surface of the wing rotating backward at the front of the fuselage being significantly smaller than the flow velocity on the wing surface of the wing rotating forward, resulting in the lift of the wing rotating backward being significantly smaller than the lift of the wing rotating forward, which still leads to the imbalance of aerodynamic forces on both sides, so that rolling torque will still appear during the deployment of the main wing.

[0047] Since there is no control surface to balance the rolling moment during the main wing deployment, the traditional method of suppressing the rolling moment through the flight control system to keep the aircraft balanced is not possible. For this reason, we considered controlling the deployment time difference of the outer wings on both sides so that the outer wing on the side of the main wing that rotates backwards can be deployed first (such as Figure 7 c, Figure 7 d and Figure 7 e), so that the airfoil of the wing part on this side is first converted into a high-lift airfoil, which can generate greater lift than the approximately symmetrical airfoil of the other wing, thereby providing a rolling restoring moment, so that the UAV is in a balanced state when the main wing and the outer wing are fully deployed. To this end, this embodiment proposes a wing deployment timing control method for a Π-type folding wing UAV, which controls the two locking mechanisms to unlock in time, so that the outer wing at the rear of the fuselage is unlocked and deployed when the main wing rotates to be perpendicular to the fuselage, and the outer wing at the front of the fuselage is unlocked and deployed before the outer wing at the rear of the fuselage by t time;

[0048] The duration t is obtained by the following process:

[0049] Step 1: Determine the time T required for the main wing to rotate from unlocking to perpendicular to the fuselage based on the rotational angular velocity of the main wing after unlocking, and set the initial value of t 初始; Determine the linear velocity of each section of the wing according to the rotation angular velocity after the main wing is unlocked, and combine the launch speed of the Π-type folding wing UAV to calculate the incoming flow velocity of each section of the wing at each moment during the process from the main wing being unlocked to rotating to a state perpendicular to the fuselage;

[0050] Step 2: Establish a first simplified three-dimensional model and a second simplified three-dimensional model of the wing, wherein the first simplified three-dimensional model is a wing model in which both outer wings on both sides are in a locked state with the main wing, such as Figure 5 As shown; the second simplified three-dimensional model is a wing model in which one side of the wing rotates backward to unfold the outer wing, and the one side of the wing rotates forward to keep the outer wing in a locked state with the main wing, as shown Figure 6 As shown;

[0051] Step 3: Using the first simplified three-dimensional model and the incoming flow velocities of each wing section obtained in step 1, with the main wing unlocked as time 0, simulate and calculate the force of the first simplified three-dimensional model in the time period Tt, and obtain the roll angle θ1 of the first simplified three-dimensional model around the longitudinal axis of the Π-type folding wing UAV;

[0052] Step 4: Using the second simplified three-dimensional model and the incoming flow velocity of each cross section of the wing obtained in step 1, the second simplified three-dimensional model is in a rolling angle state of θ1 at the moment of 0, and the force of the second simplified three-dimensional model in a time period t is simulated and calculated to obtain the rolling angle θ2 of the second simplified three-dimensional model around the longitudinal axis of the Π-type folding wing UAV;

[0053] Step 5: If the roll angle θ2 is 0°, the t value is obtained; otherwise, the t value is adjusted according to the value of the roll angle θ2, and steps 3 and 4 are repeated until the roll angle θ2 is 0°.

[0054] like Figure 7 As shown, the specific expansion sequence process is:

[0055] First, Figure 7 As shown in (a), the wings of the Π-type folding wing UAV are loaded into the launch tube in a folded state with the outer wing folded under the main wing, and are kept in the folded state under the limit constraint of the tube wall on the main wing; Figure 7 As shown in (b), after the UAV is launched from the tube, the tube wall constraint is eliminated, and the main wing is driven by the main wing rotation drive mechanism to rotate in a plane perpendicular to the longitudinal symmetry plane of the Π-type folding wing UAV. At this time, the outer wings on both sides and the main wing are in a folded state; Figure 7 (c) and Figure 7As shown in (d), the outer wing on the side rotating backward at the front of the fuselage is first deployed from the folded position under the drive of the outer wing rotation drive mechanism. The motion plane of the outer wing deployment process is perpendicular to the motion plane of the main wing deployment process. At this time, the outer wing on the side rotating forward at the rear of the fuselage remains in the folded state. If the main wing is unlocked at time 0, the outer wing on the side rotating backward at the front of the fuselage starts to be deployed under the drive of the outer wing rotation drive mechanism at time Tt. Since the outer wing rotation drive mechanism adopts a high-strength torsion spring, the outer wing deployment process is very fast. It can be almost considered that the outer wing on the side rotating backward at the front of the fuselage is deployed completely at time Tt. Figure 7 (e) and Figure 7 As shown in (f), when the main wing rotates to be perpendicular to the fuselage, the outer wing on the side of the rear part of the fuselage that rotates forward is unfolded by the outer wing rotation drive mechanism, and finally the wing unfolds as shown in Figure 7 (g) The state shown.

[0056] In this embodiment, t is determined to be 10 milliseconds through CFD simulation calculation, and the actual test flight results show that the use of this control method solves the problem of large deviation in the posture of the Π-type folding-wing UAV after it leaves the tube and the difficulty in recovering the posture, thereby achieving stable flight of the Π-type folding-wing UAV.

[0057] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary 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 without departing from the principles and intent of the present invention.

Claims

1. A method for controlling the wing deployment sequence of a Π-type folding-wing UAV, characterized in that: The wings of the folding-wing UAV are divided into a main wing and outer wings located at both ends of the main wing; the middle part of the main wing is connected to the upper part of the fuselage by a rotational manner, and the main wing can be unfolded under the drive of the main wing rotation drive mechanism, and locked when the main wing is rotated to be perpendicular to the fuselage; the inner ends of the outer wings on both sides are respectively connected to the end of one side of the main wing by a rotational manner, and locking mechanisms are respectively provided between the outer wings on both sides and the main wing. When locked, the outer wings are folded under the main wings; when the locking mechanisms are controlled to be unlocked and the fuselage has no constraints on the outer wings, the outer wings can be unfolded under the drive of the outer wing rotation drive mechanism, and the movement plane of the outer wings during the unfolding process is perpendicular to the movement plane of the main wings during the unfolding process; The timing control method is: by controlling the two locking mechanisms between the outer wing and the main wing to unlock in time, the outer wing at the rear of the fuselage is unlocked when the main wing rotates to be perpendicular to the fuselage, and the outer wing at the front of the fuselage is unlocked before the outer wing at the rear of the fuselage by t time; The duration t is obtained by the following process: Step 1: Determine the time T required for the main wing to rotate from unlocking to perpendicular to the fuselage, and set the initial value of t 初始 ; Determine the linear velocity of each section of the wing during the rotation of the main wing, and combine the launch speed of the Π-shaped folding wing UAV to calculate the incoming flow velocity of each section of the wing at each moment during the process from the main wing being unlocked to rotating to a state perpendicular to the fuselage; Step 2: Establish a first simplified three-dimensional model and a second simplified three-dimensional model of the wing, wherein the first simplified three-dimensional model is a wing model in which both outer wings on both sides are in a locked state with the main wing; the second simplified three-dimensional model is a wing model in which the outer wings of one wing rotating backward are fully unfolded, and the outer wings of the one wing rotating forward are kept in a locked state with the main wing; Step 3: Using the first simplified three-dimensional model and the incoming flow velocities of each wing section obtained in step 1, with the main wing unlocked as time 0, simulate and calculate the force of the first simplified three-dimensional model in the time period Tt, and obtain the rolling angle θ1 of the first simplified three-dimensional model around the longitudinal axis of the Π-type folding wing UAV at time Tt; Step 4: Using the second simplified three-dimensional model and the incoming flow velocity of each cross section of the wing obtained in step 1, the second simplified three-dimensional model is in a rolling angle state of θ1 as 0, and the force of the second simplified three-dimensional model in a time period t is simulated and calculated to obtain the rolling angle θ2 of the second simplified three-dimensional model around the longitudinal axis of the Π-type folding wing UAV at time t; Step 5: If the roll angle θ2 is 0°, the t value is obtained; otherwise, the t value is adjusted according to the value of the roll angle θ2, and steps 3 and 4 are repeated until the roll angle θ2 is 0°.

2. According to claim 1, a method for controlling the wing deployment sequence of a Π-type folding-wing UAV is characterized in that: In step 1, the time T required for the main wing to rotate from unlocking to a state perpendicular to the fuselage is determined according to the rotational angular velocity of the main wing after unlocking.

3. According to claim 1, a method for controlling the wing deployment sequence of a Π-type folding-wing UAV is characterized in that: In step 1, the linear velocity of each section of the wing during the main wing rotation process is determined according to the rotation angular velocity after the main wing is unlocked.

4. According to claim 1, a method for controlling the wing deployment sequence of a Π-type folding-wing UAV is characterized in that: The time length t is 10 milliseconds.

5. According to claim 1, a method for controlling the wing deployment sequence of a Π-type folding-wing UAV is characterized in that: The rear part of the fuselage of the Π-shaped folding-wing UAV adopts a retractable design.

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