A high-speed stable flight control method for a long-endurance variant unmanned aerial vehicle

Abstract

The present application discloses a high-speed stable flight control method for a long-endurance variant unmanned aerial vehicle, which relates to the field of unmanned aerial vehicle control. First, the longitudinal nonlinear dynamic equation after the deformation of the variant unmanned aerial vehicle is established in the present application. Furthermore, the longitudinal nonlinear dynamic equation is represented in the form of a nonlinear system. Then, based on the super-twisting algorithm, the speed and attitude of the nonlinear control model of the variant unmanned aerial vehicle represented in the form of a nonlinear system are decoupled, and the deformed variant unmanned aerial vehicle is controlled by using the obtained speed control sub-model and attitude control sub-model. By establishing the longitudinal nonlinear dynamic equation, the present application accurately describes the change in aerodynamic performance after the deformation of the variant unmanned aerial vehicle. Through the speed control sub-model and attitude control sub-model based on the super-twisting algorithm, the problem of high-speed stable control after the deformation of the variant unmanned aerial vehicle is solved, and the high-speed stable control after the deformation of the variant unmanned aerial vehicle is realized in the present application.

Description

Technical Field

[0001] The present application relates to the field of UAV control, and particularly to a high-speed stable flight control method for a long-endurance variable UAV. Background Art

[0002] A variable UAV refers to an unmanned aerial vehicle that can change its overall configuration through materials, structures and their mechanisms, advanced flow and flight control to adapt to different mission requirements and obtain optimal performance in different flight states. The main way for a variable UAV to deform is to change the shape of the wing, and common forms include telescopic wings, folding wings, inflatable wings and "sliding skins", etc. Among them, the variable UAV with telescopic wings has outstanding capabilities in changing the wing area and aspect ratio, and has a significant impact on the endurance performance of the aircraft, which is one of the main development directions of variable technology. This variable UAV can adjust parameters such as wing area, aspect ratio and sweep angle through the deformation of structures such as wings to adapt to different flight speeds, so as to meet the design requirements of expanding the speed range of the UAV. The deformation of the variable UAV will cause a significant change in its aerodynamic characteristics, and the deformation process has the characteristics of high nonlinearity. Existing control methods cannot achieve high-speed stable control after the deformation of the variable UAV. Summary of the Invention

[0003] The purpose of the present application is to provide a high-speed stable flight control method for a long-endurance variable UAV to achieve high-speed stable control after the deformation of the variable UAV.

[0004] To achieve the above purpose, the present application provides the following solutions.

[0005] The present application provides a high-speed stable flight control method for a long-endurance variable UAV, including the following steps.

[0006] Construct the longitudinal nonlinear dynamic equation after the deformation of the variable UAV.

[0007] Represent the longitudinal nonlinear dynamic equation in the form of a nonlinear system to obtain the nonlinear control model of the variable UAV.

[0008] Based on the super-twisting algorithm, decouple the nonlinear control model of the variable UAV into a speed control sub-model and an attitude control sub-model.

[0009] Control the deformed variable UAV according to the speed control sub-model and the attitude control sub-model.

[0010] According to the specific embodiments provided by the present application, the present application has the following technical effects.

[0011] The present application provides a high-speed stable flight control method for a long-endurance variable unmanned aerial vehicle (UAV). First, the longitudinal non-linear dynamic equation after the deformation of the variable UAV is established. Then, the longitudinal non-linear dynamic equation is expressed in the form of a non-linear system to obtain the non-linear control model of the variable UAV. Subsequently, based on the super-twisting algorithm, the non-linear control model of the variable UAV is decoupled into speed and attitude. The decoupled speed control sub-model and attitude control sub-model are used to control the deformed variable UAV. By establishing the longitudinal non-linear dynamic equation, the present application accurately describes the change in aerodynamic performance after the deformation of the variable UAV, and designs a speed control sub-model and an attitude control sub-model based on the super-twisting algorithm for the UAV to achieve high-speed stable flight after the modal transition, thus solving the problem of high-speed stable control of the variable UAV after deformation. The present application realizes the high-speed stable control of the variable UAV after deformation. Description of the Drawings

[0012] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 It is a schematic flowchart of a high-speed stable flight control method for a long-endurance variable UAV provided by an embodiment of the present application.

[0014] Figure 2 It is a schematic diagram of the principle of a high-speed stable flight control method for a long-endurance variable UAV provided by an embodiment of the present application. Detailed Embodiments

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0016] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0017] In an exemplary embodiment, to overcome the non-linear system control problem caused by the change in aerodynamic characteristics after the deformation of the variable UAV, the present invention proposes a high-speed stable flight control method for a long-endurance variable UAV, as shown in Figure 1 and Figure 2As shown, it includes the following steps 101 - 104.

[0018] Step 101, construct the longitudinal non - linear dynamic equation after the variant UAV deforms.

[0019] Step 102, represent the longitudinal non - linear dynamic equation in the form of a non - linear system to obtain the non - linear control model of the variant UAV.

[0020] Step 103, based on the super - twisting algorithm, decouple the non - linear control model of the variant UAV into a speed control sub - model and an attitude control sub - model.

[0021] Step 104, control the deformed variant UAV according to the speed control sub - model and the attitude control sub - model.

[0022] Implementing the above steps 101 - 104 can achieve high - speed and stable control of the variant UAV after deformation.

[0023] In an exemplary embodiment, according to the traditional UAV dynamic equation, combined with the additional moment caused by the change in aerodynamic performance after the variant UAV deforms, the longitudinal non - linear dynamic equation of the variant UAV after deformation is derived, that is, the longitudinal non - linear dynamic equation constructed in step 101 above.

[0024] This longitudinal non - linear dynamic equation is shown in Equation (1).

[0025] (1).

[0026] Where, is the flight speed of the variant UAV; is the first - order derivative of, representing the flight acceleration of the variant UAV; is the first - order derivative of, is the flight altitude of the variant UAV; is the pitch angle of the variant UAV, is the first - order derivative of; is the angle of attack of the variant UAV, is the first - order derivative of; is the pitch angular velocity of the variant UAV, is the first - order derivative of; is the drag during the flight of the variant UAV, is the deformation parameter of the variant UAV, is the engine thrust of the variant UAV, , is the engine thrust coefficient of the variant UAV, represents the throttle setting, is the mass of the variant UAV, is the acceleration due to gravity, is the flight path angle of the variant UAV, During the deformation of the variant UAV, the inertial force generated around the axis; is the lift force during the flight of the variant UAV, During the deformation of the variant UAV, the inertial force generated around the axis; is the moment of inertia about the pitch axis of the variant UAV, is the first derivative of, is the static moment of the variant UAV about the axis, is the pitch moment during the flight of the variant UAV, During the deformation of the variant UAV, the moment of inertia generated around the axis; is the position of the engine axis of the variant UAV.

[0027] Among the above parameters, the flight acceleration of the variant UAV is measured by a triaxial accelerometer; the flight speed of the variant UAV is obtained by integrating the acceleration data; the flight altitude of the variant UAV is measured by a barometric altimeter; the pitch angular velocity of the variant UAV is measured by a triaxial gyroscope; the flight angle of attack , pitch angle and flight path angle of the variant UAV are obtained by integrating the angular acceleration data measured by a triaxial gyroscope; the mass of the variant UAV, the moment of inertia about the pitch axis of the variant UAV, the position of the engine axis of the variant UAV, and the static moment of the variant UAV are all UAV design parameters.

[0028] The inertial force generated around the axis during the deformation of the variant UAV in formula (1), the inertial force generated around the axis during the deformation of the variant UAV, and the moment of inertia generated around the axis during the deformation of the variant UAV characterize the additional forces and additional moments on the UAV after deformation and can be calculated using equation (2).

[0029] (2).

[0030] Among them, is the first derivative of is the second derivative of

[0031] The lift during the flight of the variant UAV in formula (1) the drag during the flight of the variant UAV and the pitching moment during the flight of the variant UAV can be calculated by formula (3).

[0032] (3).

[0033] Among them, is the atmospheric density, is the wing area of the variant UAV, is the lift coefficient with respect to the deformation parameter of the variant UAV, is the drag coefficient with respect to the deformation parameter of the variant UAV, is the pitching moment coefficient with respect to the deformation parameter of the variant UAV, is the mean aerodynamic chord length of the variant UAV.

[0034] Among the above parameters, and are both design parameters of the variant UAV; is a function of the flight altitude of the variant UAV and can be calculated from the flight altitude of the variant UAV; can represent the wingspan, sweep angle, etc., and can be specifically determined according to the deformation characteristics of the actual variant UAV.

[0035] Furthermore, , and in formula (3) above are determined according to the deformation parameter of the variant UAV. Taking the variable-sweep UAV as an example, the deformation parameter of the variant UAV can be specifically quantified as the sweep angle of the variant UAV. At this time, the calculation formulas of , and are as shown in formula (4).

[0036] (4).

[0037] Among them, represents the sweep angle of the variable UAV, , is the lift coefficient when the angle of attack of the variable UAV is 0, is the first-order coefficient of the lift coefficient, is the drag coefficient when the angle of attack of the variable UAV is 0, is the first-order coefficient of the drag coefficient, is the second-order coefficient of the drag coefficient, is the angle of attack of the variable UAV , the pitch rudder deflection angle and the pitch angular velocity are all 0, and the pitch moment coefficient, is the angle-of-attack term coefficient of the pitch moment coefficient, is the pitch-rudder-deflection-term coefficient of the pitch moment coefficient, is the pitch-angular-velocity-term coefficient of the pitch moment coefficient, is the mean aerodynamic chord length of the variable UAV.

[0038] In the above formula (4), for the lift coefficient of the variable UAV with respect to the deformation parameter , is linearized into a linear function of the angle of attack of the variable UAV; for the drag coefficient of the variable UAV with respect to the deformation parameter , is fitted into a quadratic function of the angle of attack of the variable UAV; for the pitch moment coefficient of the variable UAV with respect to the deformation parameter , it is fitted as a composite function of the angle of attack , the pitch rudder deflection angle and the pitch angular velocity of the variable UAV. Among them, , , , , , , , , are all coefficient terms in the aerodynamic parameters of the variable UAV. These parameters are all functions of the sweep angle, and the specific numerical values of the parameters can be obtained through wind tunnel tests or CFD (Computational Fluid Dynamics) calculations according to different sweep angles.

[0039] In another exemplary embodiment, in step 102 of the present application, the longitudinal dynamics of the variant unmanned aerial vehicle established in step 101, i.e., Equation (1), is represented in the form of a nonlinear system to obtain the nonlinear control model of the variant unmanned aerial vehicle, as shown in Equation (5).

[0040] (5).

[0041] Wherein, is the system state variable, , is the first derivative of, is the system state output quantity, is the flight speed of the variant unmanned aerial vehicle, is the angle of attack of the variant unmanned aerial vehicle, is the pitch angle of the variant unmanned aerial vehicle, is the pitch angular velocity of the variant unmanned aerial vehicle, is the flight altitude of the variant unmanned aerial vehicle, and the superscript T represents transpose, represents the system input variable, , represents the pitch rudder deflection angle, represents the throttle amount, represents the disturbance term of the uncertainty in the modeling process, is the system function matrix; is the system gain matrix.

[0042] Wherein, the specific form of the system function matrix is as shown in Equation (6).

[0043] (6).

[0044] In the formula, is the mass of the variant unmanned aerial vehicle, is the atmospheric density, is the wing area of the variant unmanned aerial vehicle, is the drag coefficient with respect to the deformation parameter of the variant unmanned aerial vehicle, is the static moment of the variant unmanned aerial vehicle about the axis, is the first derivative of, is the first derivative of, is the second derivative of, is the lift coefficient with respect to the deformation parameter of the variant unmanned aerial vehicle, is the acceleration due to gravity, is the flight path angle of the variant unmanned aerial vehicle.

[0045] The specific form of the system gain matrix is shown in Equation (7).

[0046] (7).

[0047] In the formula, is the engine thrust coefficient of the variant UAV.

[0048] In Equations (5)-(7), is determined by the engine model.

[0049] In another exemplary embodiment, in step 103 of the present application, based on the non-linear control model of the variant UAV established in the above step 102, for the system state variable the flight speed of the variant UAV in a speed control sub-model of the variant UAV is established, as shown in Equation (8).

[0050] (8).

[0051] Wherein, is the desired flight speed of the variant UAV, is the flight speed of the variant UAV, is the tracking error between the speed and the desired speed, is the sliding mode variable of the speed control sub-model, is an intermediate variable of the speed control sub-model and has no practical meaning, is the first derivative of, is the first derivative of, and are both adaptive parameters of the speed control sub-model designed by the super-twisting controller, is the first derivative of, and are two observer functions for speed control, is the first derivative of, t is the time variable, is the mass of the variant UAV, is the static gain, , , are all preset positive constants in the speed control sub-model, is used to judge the absolute value of the positive small quantity, is a preset parameter and can be valued according to experience, is the control quantity of the speed control sub-model, represents the throttle amount, is the system function matrix, is the system gain matrix, is the deformation parameter of the variant UAV, is the system state variable.

[0052] In Equation (8), is used to determine the sign of the sliding mode surface, and the expected flight speed of the variant UAV is the flight speed of the variant UAV defined by the user and can take values within the flight envelope determined during the design of the variant UAV; the design parameters related to the sliding mode algorithm can be obtained through iteration in the simulation, and the initial assignment can be determined by referring to typical examples.

[0053] In another exemplary embodiment, in step 103 of the present application, based on the non-linear control model of the variant UAV established in the above step 102, for the system state variable the pitch angular velocity in , an attitude control sub-model is established, as shown in Equation (9).

[0054] (9).

[0055] Wherein, is the expected pitch angle of the variant UAV, is the pitch angle of the variant UAV, is the tracking error between the pitch angle and the expected pitch angle, is the tracking error between the pitch angular velocity and the expected pitch angular velocity, is the first derivative of, is the second derivative of, is the pitch angular velocity of the variant UAV, is the sliding mode variable of the attitude control sub-model, is the first derivative of, is the intermediate variable of the attitude control sub-model, and are the sliding mode surface design parameters; is the intermediate function, , is the average sliding mode surface, , and are the first intermediate variable and the second intermediate variable respectively, , , is used to judge the absolute value of a small positive number, is a positive real number between 0 and 1, is the first derivative of, and are both adaptive parameters of the attitude control sub-model in the design of the superhelical controller, is the first derivative of, and are two observer functions for attitude control, is the sign function in the sliding mode control law, is the mass of the variant UAV, is the static gain, is the first derivative of, , and are all preset positive constants in the speed control sub-model, is used to judge the absolute value size of the positive small quantity, is the control quantity of the attitude control sub-model, is a preset parameter, represents the pitch rudder deflection angle, is the system function matrix, is the system gain matrix, is the deformation parameter of the variant UAV, is the system state variable.

[0056] In another exemplary embodiment, the above step 104 controls the stable flight of the variant UAV based on the speed control sub-model and the attitude control sub-model in step 103. First, the system state variable is obtained based on the on-board sensors of the variant UAV. Then, according to the system state variable, the throttle amount is determined using the speed control sub-model, and according to the system state variable, the pitch rudder deflection angle is determined using the attitude control sub-model. Then, the flight speed and flight attitude of the variant UAV are controlled according to the throttle amount and the pitch rudder deflection angle.

[0057] Exemplarily, the speed control sub-model and the attitude control sub-model obtained in the above embodiment can be deployed on the flight control system of the variant UAV to achieve the control of the long-endurance variant UAV. The flight control system mainly includes: a main control unit, servo equipment, and various types of sensors.

[0058] The main control unit optimizes and controls the flight performance of the variant UAV by integrating the designed control algorithm; the servo equipment realizes specific control instructions by receiving the control signal of the main control unit; various types of sensors collect various flight data of the variant UAV, mainly including: a three-axis rate gyroscope for collecting the flight angular velocity of the variant UAV, a three-axis accelerometer for measuring the acceleration of the variant UAV in three-dimensional space, a barometric altimeter for measuring the flight altitude of the variant UAV, and an airspeed sensor for measuring the flight speed of the variant UAV.

[0059] Step 104 above specifically includes the following steps 201 to 204.

[0060] Step 201, obtaining the system state variables of the variant UAV through the on-board sensors of the variant UAV .

[0061] Step 202, calculating the tracking error according to the system state variables , and .

[0062] Step 203, inputting the calculated tracking error , and into the main control unit of the flight control system of the variant UAV, and planning the control instructions for the throttle amount and pitch rudder deflection angle of the variant UAV according to the control algorithms (speed control sub-model and attitude control sub-model) deployed on the main control unit.

[0063] Step 204, sending the control instructions to the actuators of the engine and control surfaces of the variant UAV, adjusting the flight speed and flight attitude of the variant UAV, and completing the stable control.

[0064] According to the specific embodiments provided in the present application, the present application has the following technical effects.

[0065] The high-speed stable flight control method for the long-endurance variant UAV provided in the above embodiments of the present application can address the high-speed stable flight control problem after the modal transformation of the variant UAV. The longitudinal nonlinear dynamic equation established in the present application can accurately describe the change in aerodynamic performance after the deformation of the variant UAV. The control method (i.e., the super-twisting algorithm) based on the sliding mode surface in the present application enables the system state variables to converge quickly, making the system more robust and having better anti-interference ability. The present application provides a general control method for various variant UAVs based on wing structure deformation, providing a theoretical and practical basis for engineering applications.

[0066] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0067] In this article, specific examples are used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A high-speed and stable flight control method for a long-flight variant UAV, characterized in that: include: Construct the longitudinal nonlinear dynamic equations of the deformed UAV; The longitudinal nonlinear dynamic equation is expressed in a nonlinear system form to obtain a nonlinear control model of the variant UAV; Based on the super-helix algorithm, the nonlinear control model of the variant UAV is decoupled into a speed control sub-model and an attitude control sub-model; Controlling the deformed variant UAV according to the speed control sub-model and the attitude control sub-model; The longitudinal nonlinear dynamic equation is: ； in, is the flight speed of the variant drone; for The first derivative of , characterizes the flight acceleration of the variant UAV; for The first derivative of is the flight altitude of the variant drone; is the pitch angle of the variant drone, for The first derivative of ; is the angle of attack of the variant drone, for The first derivative of ; is the pitch angular velocity of the variant drone, for The first derivative of ; is the resistance of the variant drone during flight. is the deformation parameter of the variant drone, is the engine thrust of the variant drone, , is the engine inference coefficient of the variant UAV, Indicates the throttle amount. is the quality of the variant drone, is the acceleration due to gravity, is the flight path angle of the variant drone, For the transformation process of the variant drone Inertial force generated by the shaft; is the lift of the variant UAV during flight. For the transformation process of the variant drone Inertial force generated by the shaft; is the pitch axis inertia moment of the variant UAV, for The first derivative of For variant drones Static moment of the shaft, is the pitch moment of the variant UAV during flight, For the transformation process of the variant drone The moment of inertia of the axis, This is the engine axis position of the variant UAV.

2. The high-speed stable flight control method for a long-flight variant UAV according to claim 1 is characterized in that: The variant drone is circling during the transformation process Inertial force generated by the shaft , the variant drone is around during the deformation process Inertial force generated by the shaft And the variant drone is around during the deformation process Moment of inertia of the axis The calculation formula is as follows: ； in, for The first derivative of for The second derivative of .

3. The high-speed stable flight control method for a long-flight variant UAV according to claim 1 is characterized in that: The calculation formulas for the drag, lift and pitch moment of the variant UAV during flight are as follows: ； in, is the atmospheric density, is the wing area of ​​the variant UAV, For the deformation parameters of the variant drone The lift coefficient, For the deformation parameters of the variant drone The drag coefficient, For the deformation parameters of the variant drone The pitching moment coefficient, is the average aerodynamic chord length of the variant UAV.

4. The high-speed stable flight control method for a long-flight variant UAV according to claim 3 is characterized in that: The deformation parameter of the variant drone is the sweep angle of the variant drone. The calculation formulas for the lift coefficient, drag coefficient and pitching moment coefficient are as follows: ； in, Indicates the sweep angle of the variant drone, , is the lift coefficient of the variant UAV when the angle of attack is 0, is the first-order coefficient of the lift coefficient, is the drag coefficient of the variant UAV when the angle of attack is 0, is the first-order coefficient of the resistance coefficient, is the quadratic coefficient of the drag coefficient, The angle of attack of the variant drone 、Pitch rudder deflection angle and pitch angular velocity The pitching moment coefficient when both are 0, is the angle of attack term of the pitching moment coefficient, is the pitching rudder angle term coefficient of the pitching moment coefficient, is the pitching angular velocity term coefficient of the pitching moment coefficient, is the average aerodynamic chord length of the variant UAV.

5. The high-speed stable flight control method for a long-flight variant UAV according to claim 1 is characterized in that: The nonlinear control model of the variant UAV is: ； in, is the system state variable, , for The first derivative of is the system status output, is the flight speed of the variant drone, is the angle of attack of the variant drone, is the pitch angle of the variant drone, is the pitch angular velocity of the variant drone, is the flight altitude of the variant drone, and the superscript T indicates transposition. Represents the system input variable, , represents the pitch rudder angle, Indicates the throttle amount. The interference term represents the uncertainty in the modeling process, is the system function matrix; is the system gain matrix; ； is the quality of the variant drone, is the atmospheric density, is the wing area of ​​the variant UAV, For the deformation parameters of the variant drone The drag coefficient, For variant drones Static moment of the shaft, for The first derivative of for The first derivative of for The second-order derivative of For the deformation parameters of the variant drone The lift coefficient, is the acceleration due to gravity, is the flight path angle of the variant drone; ； is the engine inference coefficient of the variant UAV.

6. The high-speed stable flight control method for a long-flight variant UAV according to claim 1 is characterized in that: The speed control sub-model is: ； in, is the expected flight speed of the variant drone, is the flight speed of the variant drone, is the tracking error between the velocity and the desired velocity, is the sliding mode variable of the speed control sub-model, is the intermediate variable of the speed control sub-model, for The first derivative of for The first derivative of and These are the adaptive parameters of the speed control sub-model designed for the super-helical controller. for The first derivative of and are the two observer functions for speed control, for The first derivative of is the time variable, is the sign function in the sliding mode control law, For the quality of the variant drone, is the static gain, , , are all positive constants preset in the speed control sub-model. For judging A small positive number of absolute value, is the preset parameter, is the control quantity of the speed control sub-model, Indicates the throttle amount. is the system function matrix, is the system gain matrix, is the deformation parameter of the variant drone, is the system state variable.

7. The high-speed stable flight control method for a long-flight variant UAV according to claim 1, characterized in that: The posture control sub-model is: ； in, is the desired pitch angle of the variant drone, is the pitch angle of the variant drone, is the tracking error between the pitch angle and the desired pitch angle, is the tracking error between the pitch angular velocity and the desired pitch angular velocity, for The first derivative of for The second-order derivative of is the pitch angular velocity of the variant drone, is the sliding mode variable of the attitude control sub-model, for The first derivative of is the intermediate variable of the attitude control sub-model, and Design parameters for the sliding surface; is the intermediate function, , is the average synovial surface, , and are the first intermediate variable and the second intermediate variable respectively, , , For judging A small positive number of absolute value, is a positive real number between 0 and 1; for The first derivative of and These are the adaptive parameters of the attitude control sub-model designed for the super-helical controller. for The first derivative of and are the two observer functions for attitude control, is the sign function in the sliding mode control law, For the quality of the variant drone, is the static gain, for The first derivative of , and are all positive constants preset in the speed control sub-model. For judging A small positive number of absolute value, is the preset parameter, is the control quantity of the attitude control sub-model, represents the pitch rudder angle, is the system function matrix, is the system gain matrix, is the deformation parameter of the variant drone, is the system state variable.

8. The high-speed stable flight control method for a long-flight variant UAV according to claim 1 is characterized in that: Controlling the deformed variant UAV according to the speed control sub-model and the attitude control sub-model specifically includes: Obtain system state variables based on the variant UAV's onboard sensors; Determine the throttle amount using the speed control sub-model according to the system state variable; Determining the pitch rudder deflection angle using the attitude control sub-model according to the system state variables; The flight speed and flight attitude of the variant UAV are controlled according to the throttle amount and the pitch rudder deflection angle.

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