Reusable aircraft control method based on control surface distribution

Abstract

The invention provides a control plane distribution-based reusable aircraft control method. The method comprises the following steps of: constructing a dynamic system of a reusable aircraft and a prediction model of sweepback wing and elevator plane distribution; a prediction controller for high-maneuverability guidance is designed based on the coupling characteristics of the sweepback wings and the elevator surfaces; the predictive controller is used for controlling the reusable aircraft to fly on a preset reference profile, and speed and height tracking is achieved. According to the invention, the problem that the sweepback wings and the lifting control surface cannot be considered together under the condition of multiple execution mechanisms of the reusable aircraft is solved, and the control complexity of the reusable aircraft is improved; through model predictive control, the influence of a sweepback wing and an elevator plane of the reusable aircraft on control is reduced; height and speed tracking errors are effectively reduced; the model prediction controller can control the reusable aircraft to fly in a predetermined reference profile, so that speed and height tracking of the reusable aircraft is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft control, and particularly to a control method for reusable aircraft based on rudder surface allocation. Background Art

[0002] With the rapid evolution of aerospace technology, reusable aircraft have gradually become the core object of near-space flight research. Such aircraft have the advantages of strong reusability and high mission adaptability, and can perform complex flight missions under multi-task and multi-environment conditions. Therefore, they are regarded as an important way to achieve efficient cross-airspace flight.

[0003] Compared with the performance bottlenecks faced by traditional aircraft in a wide speed range and cross-airspace flight, reusable aircraft are more superior in terms of adaptability and maneuverability. However, at the same time, the high complexity of its operating environment also poses severe challenges to the design of the control system. During the flight process, there are often various non-linear disturbance factors such as model uncertainty, external interference, and system state changes, which put forward higher requirements for the accuracy and robustness of the control algorithm.

[0004] In recent years, although technologies such as adaptive control, optimal control, sliding mode control, and disturbance rejection control have made remarkable progress in this field, due to the limitations of ground test conditions, it is still difficult to obtain complete and accurate aerodynamic characteristic data, further exacerbating the uncertainty of control design.

[0005] In the process of constructing an actual control system, it is necessary to effectively consider the physical constraints of the aircraft, especially the amplitude and rate limitations of the actuators. At the same time, enhancing the system's ability to cope with non-linear and time-varying disturbances has become a key issue in the optimization of the control strategy for reusable aircraft. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a control method for reusable aircraft based on rudder surface allocation. The present invention solves the problem that the sweep angle and elevator deflection cannot be considered jointly in the flight environment of reusable aircraft under the conditions of non-linear disturbances, physical constraints, and mission switching, and improves the control stability and maneuverability of reusable aircraft.

[0007] The technical solution of the present invention is as follows: A control method for reusable aircraft based on rudder surface allocation, comprising the following steps:

[0008] S1), construct the dynamic system of the reusable aircraft;

[0009] S2), construct the prediction model of the swept wing and elevator surface allocation;

[0010] S3), Design a predictive controller for high-maneuver guidance based on the coupling characteristics of the swept wing and the elevator surface;

[0011] S4), Use the designed predictive controller to control the reusable vehicle to fly on a predetermined reference profile, and achieve the tracking of speed and altitude.

[0012] Preferably, in step S1), constructing the dynamic system of the reusable vehicle specifically includes the following steps:

[0013] S11), In the ground coordinate system, establish the translational dynamic vector equation of the center of mass of the reusable vehicle:

[0014]

[0015] In the formula, m is the instantaneous mass of the reusable vehicle, with the unit of kg; V is the velocity vector of the reusable vehicle, with the unit of m / s; R and G are the aerodynamic force and the gravitational force respectively, with the unit of N;

[0016] S12), Obtain according to the relationship between the relative derivative and the absolute derivative of the vector:

[0017]

[0018] In the formula, is the time derivative of the reusable vehicle relative to the orbital coordinate system, with the unit of m / s 2 ; Ω is the rotational angular velocity vector of the orbital coordinate system, with the unit of rad / s;

[0019] S13), According to the definition of the orbital coordinate system, obtain the components of the center-of-mass velocity vector V of the reusable vehicle on the Ox2y2z2 axes as:

[0020]

[0021] In the formula, V x2 、V y2 、V z2 are the components of the center-of-mass velocity vector V of the reusable vehicle on the Ox2y2z2 axes respectively;

[0022] S14), According to the dynamic equation, obtain the scalar form of the dynamic equation of the translational motion of the center of mass of the reusable vehicle:

[0023]

[0024] Among them, t is the time; θ is the flight path angle; γ is the flight path angle; T, D, and L are the thrust, drag, and lift respectively.

[0025] Preferably, in step S2), the expression of the dynamic equation of the swept wing and elevator surface for the longitudinal speed loop of the reusable vehicle is as follows:

[0026]

[0027] In the formula, is the first derivative of the velocity vector V of the reusable vehicle; is the first derivative of the flight path angle γ; T is the thrust term; F V is the measurable term related to the flight path angle; respectively represent the uncertain vector terms related to velocity; Ψ V,1 、Ψ V,2 respectively represent the measurable vectors related to velocity; S(Φ c ) represents the fuel ratio constraint; Φ c is the fuel ratio; represents the altitude derivative; F γ represents the measurable term related to the flight path angle; respectively represent the uncertain vector terms related to the flight path angle; Ψ γ,1 、Ψ γ,2 、Ψ γ,3 respectively represent the measurable vectors related to the flight path angle; α is the angle of attack; is the derivative of the angle of attack; δ c represents the swept wing; Q is the pitch rate; is the derivative of the pitch rate; ζ Q,2 respectively represent the uncertain vector terms related to the pitch rate; Ψ Q,1 、Ψ Q,2 respectively represent the measurable vectors related to the pitch rate; δ e represents the elevator surface deflection angle; d V 、d γ 、d Q are the disturbance terms.

[0028] Preferably, in step S2), during the altitude loop control of the reusable vehicle, the swept wing and elevator surface are distributed in a chained manner with the aerodynamic rudder, that is, when the aerodynamic rudder cannot meet the maneuverability requirements, the swept wing and elevator surface are triggered to deflect; and it is assumed that the thrust coefficient k Φ satisfies:

[0029]

[0030] In the formula, K, are the maximum and minimum values of the thrust coefficient respectively; k Φ is the thrust coefficient; δ Tare the sweep angle of the wing and the deflection angle of the elevator surface.

[0031] Preferably, in step S2), the thrust term T and the fuel ratio Φ c satisfy a linear relationship:

[0032] T = k Φ Φ c ;

[0033] s.t. (0 ≤ Φ c ≤ 1); (7)

[0034] where the thrust coefficient k Φ is the ratio of the maximum thrust to the maximum fuel ratio.

[0035] Preferably, in step S3), the design of the predictive controller for high-maneuver guidance includes the following steps:

[0036] S31), Calculate the speed and altitude errors of the reusable vehicle;

[0037] S32), Design a predictive controller for the altitude error and speed error in a manner that meets the requirements of the Lyapunov function, that is:

[0038]

[0039] In the formula, is the derivative of the Lyapunov function; e V is the speed error; is the reciprocal of the speed error; is the derivative of the reference speed; Φ c is the fuel ratio; d V is the disturbance term; respectively represent the uncertain vector terms related to speed; Ψ V,1 , Ψ V,2 respectively represent the measurable vectors related to speed; F V represents the measurable vector related to speed;

[0040] S33), Connect the designed predictive controller to the output end; the output end includes the control surface and the engine fuel ratio.

[0041] Preferably, in step S4), use the designed predictive controller to control the reusable vehicle to fly on a predetermined reference profile, specifically including the following steps:

[0042] S41), Task profile acquisition: According to the flight mission requirements, obtain the target reference altitude and speed profile of the aircraft as the external reference input of the predictive controller;

[0043] S42) Speed control loop design: The error between the current flight speed and the target reference speed is introduced as the input quantity into the predictive controller; the controller predicts and optimizes the control output based on this speed error to generate an appropriate fuel ratio command; by adjusting the fuel ratio, the acceleration or deceleration of the aircraft is achieved, so that the actual speed gradually converges to the reference speed, realizing the closed-loop tracking and error minimization of the flight speed.

[0044] S43) Altitude control loop design: The deviation between the current altitude of the aircraft and the reference altitude is input into the predictive controller. The controller outputs the corresponding elevator deflection angle command and calculates the corresponding control moment based on the deflection angle; through the angle adjustment of the control surface and the application of aerodynamic moment, the dynamic regulation of the flight altitude is realized, so that the aircraft maintains stable flight on the preset altitude trajectory.

[0045] The beneficial effects of the present invention are as follows:

[0046] 1. The present invention solves the problem that the reusable aircraft cannot be considered jointly when the swept wing and the elevator are involved at the same time, and improves the control stability and maneuverability of the reusable aircraft.

[0047] 2. The present invention reduces the influence of the coupling between the swept wing and the elevator of the reusable aircraft through model predictive control; thus, the height and speed tracking errors can be effectively reduced.

[0048] 3. The controller of the present invention can control the reusable aircraft to fly within a predetermined reference profile, thereby realizing the speed and altitude tracking of the reusable aircraft. Description of the Drawings

[0049] Figure 1 is a schematic flow chart of the control method according to the embodiment of the present invention;

[0050] Figure 2 is a diagram of the tracking error of the predictive controller of the reusable aircraft in the embodiment of the present invention. Detailed Embodiment

[0051] The following further describes the specific embodiments of the present invention with reference to the drawings:

[0052] As Figure 1 shown, a control method for a reusable aircraft based on control surface allocation in this embodiment includes the following steps:

[0053] S1) Construct the dynamic system of the reusable aircraft; specifically, it includes the following steps:

[0054] S11) In the ground coordinate system, establish the translational dynamics vector equation of the center of mass of the reusable aircraft:

[0055]

[0056] Wherein, m is the instantaneous mass of the reusable vehicle, with the unit of kg; V is the velocity vector of the reusable vehicle, with the unit of m / s; R and G are the aerodynamic force and the gravitational force respectively, with the unit of N;

[0057] S12) Since the orbital coordinate system has displacement motion and rotational motion relative to the ground coordinate system; therefore, according to the relationship between the relative derivative and the absolute derivative of the vector, it can be obtained that:

[0058]

[0059] Wherein, is the time derivative of the reusable vehicle relative to the orbital coordinate system, with the unit of m / s 2 ; Ω is the rotational angular velocity vector of the orbital coordinate system, with the unit of rad / s;

[0060] S13) According to the definition of the orbital coordinate system, the components of the centroid velocity vector V of the reusable vehicle on the Ox2y2z2 axes are:

[0061]

[0062] Wherein, V x2 、V y2 、V z2 are the components of the centroid velocity vector V of the reusable vehicle on the Ox2y2z2 axes respectively;

[0063] S14) According to the dynamic equation, the scalar form of the dynamic equation of the centroid translation of the reusable vehicle is obtained:

[0064]

[0065] Wherein, t is the time; θ is the flight path angle; γ is the flight path angle; T, D, and L are the thrust, drag, and lift respectively.

[0066] S2) Construct a prediction model for the distribution of the swept wing and the elevator surface;

[0067] In the control design, set the current moment as k, the control time domain interval as Δk, and the system predicts the control input and the system response for the next N steps within this interval; wherein, the control input sequence U(k) is defined as:

[0068] U(k) = {u(k|k), u(k + 1|k), …, u(k + N - 1|k)}; (9)

[0069] The corresponding system output prediction sequence Y(k) is:

[0070] Y(k) = {y(k + 1|k), y(k + 2|k), …, y(k + N|k)}; (10)

[0071] Wherein, i(k|k) represents the control input calculated based on the current system state at time step k; the subscript k∣k represents the control input calculated under the known system state at the current time k; y(k + 1|k) represents the predicted output at time step k + 1, provided that the state at time step k is known.

[0072] In this embodiment, to ensure the output tracking performance and control the smoothness of the input change, the following cost function is introduced as the optimization objective function:

[0073]

[0074] Wherein, J represents the cost function; y ref (k + j) represents the reference output trajectory at the (k + j)-th step; represents the transpose operation; Q j represents the weight matrix of the predicted output error at the j-th step; Δu(k + j - 1) = u(k + j - 1) - u(k + j - 2) represents the input difference between the (k + j - 1)-th step and the (k + j - 2)-th step.

[0075] In this embodiment, to meet the physical limitations of the rudder surface, the following constraints are introduced:

[0076]

[0077] Wherein, u min , u max respectively represent the minimum and maximum values of the input value during the input process; u(k + j|k) represents the predicted input value at the (k + j)-th step given the k-th step; Δu min , Δu max respectively represent the minimum and maximum values of the input variable during the input process; Δu(k + j) represents the input difference at the (k + j)-th step.

[0078] In this embodiment, to more realistically reflect the dynamic behavior of the rudder surface, the following first-order response model of the rudder surface is introduced

[0079]

[0080] Wherein, δ(t) is the actual rudder surface angle; δ u (t) is the controller given value; τ is the time constant.

[0081] In this embodiment, a model predictive control strategy is adopted. According to the current state of the aircraft, the future control input sequence is predicted and optimized, and the linkage control is carried out in combination with the sweep angle and the elevator angle, and the following contents are considered during the control process:

[0082] The control target is to track the preset flight altitude or trajectory of the aircraft;

[0083] The control input sequence U(k) and output sequence Y(k) depend on future state estimates within the prediction interval N; the cost function J comprehensively considers the output error and the control variation; the controller optimization process is limited by the control amplitude and rate; the rudder channel is modeled as a first-order system, and the dynamic response is incorporated into the optimization process; and it can be extended to multi-channel (such as rudder, flaperon) integrated distributed control scenarios.

[0084] Then, a model of the influence of the swept wing and elevator surface objects on the longitudinal velocity loop of the reusable aircraft is established; its expression is:

[0085]

[0086] Where, is the first derivative of the velocity vector V of the reusable vehicle; is the first-order derivative of the track angle γ; T is the thrust term; F V is a measurable speed-related item; They represent the uncertainty vector terms related to velocity; V,1 , Ψ V,2 Respectively represent the measurable vectors related to velocity; S(Φ c ) represents the fuel ratio constraint; Φ c is the fuel ratio; represents the height derivative; F γ Represents a measurable item related to the track angle; Represent the uncertainty vector terms related to the track angle; γ,1 , Ψ γ,2 , Ψ γ,3 They represent the measurable vectors related to the track angle; α is the angle of attack; is the derivative of the angle of attack; δ c represents the swept wing; Q is the pitch rate; is the derivative of the pitch angular rate; ζ Q,2 Respectively represent the uncertainty vector terms related to the pitch angular rate; Ψ Q,1 , Ψ Q,2 Respectively represent the measurable vectors related to the pitch angular rate; δ e Indicates the deflection angle of the elevator surface; d V d γ d Q is an interference item.

[0087] in:

[0088]

[0089] In the formula, S represents; S / m represents the ratio of the reference area to the mass; respectively represent the aerodynamic parameters related to the thrust term; the aerodynamic parameters related to the thrust and fuel ratio; represents; respectively represent the aerodynamic parameters related to the drag; represents the dynamic pressure.

[0090] In this embodiment, for the reusable aircraft during the altitude loop control process, the swept wing, the elevator surface and the aerodynamic rudder are distributed in a chain-like manner, that is, when the aerodynamic rudder cannot meet the maneuverability requirements, the swept wing and the elevator surface are triggered to deflect; and it is assumed that the thrust coefficient k Φ satisfies:

[0091]

[0092] In the formula, K, are respectively the maximum value and the minimum value of the thrust coefficient; k Φ is the thrust coefficient; δ T is the deflection angle of the swept wing and the elevator surface.

[0093] The thrust term T and the fuel ratio Φ c satisfy a linear relationship:

[0094] T = k Φ Φ c ;

[0095] s.t. (0 ≤ Φ c ≤ 1); (7)

[0096] wherein, the value of the thrust coefficient k Φ corresponds to the ratio of the maximum thrust to the maximum fuel ratio.

[0097] S3), Design a predictive controller for high-maneuver guidance based on the coupling characteristics of the swept wing and the elevator surface; including the following steps:

[0098] S31), Calculate the speed and altitude errors of the reusable aircraft;

[0099] S32), Design a predictive controller for the altitude error and the speed error in a manner that meets the requirements of the Lyapunov function, that is:

[0100]

[0101] In the formula, is the derivative of the Lyapunov function; e V is the speed error; is the reciprocal of the speed error; is the derivative of the reference speed; Φ c is the fuel ratio; d V is the interference term; respectively represent the uncertain vector terms related to speed; Ψ V,1 and Ψ V,2 respectively represent the measurable vectors related to speed; F V represents the measurable term related to speed;

[0102] S33) Connect the designed predictive controller to the output end; the output end includes the control surface and the engine fuel ratio.

[0103] S4) Use the designed predictive controller to control the reusable vehicle to fly on a predetermined reference profile, realizing the tracking of speed and altitude, specifically including the following steps:

[0104] S41) Task profile acquisition: According to the flight mission requirements, obtain the target reference altitude and speed profile of the vehicle as the external reference input of the predictive controller;

[0105] S42) Speed control loop design: Introduce the error between the current flight speed and the target reference speed as the input quantity into the predictive controller; the controller predicts and optimizes the control output according to this speed error, generating a suitable fuel ratio command; by adjusting the fuel ratio, the vehicle is accelerated or decelerated, so that the actual speed gradually converges to the reference speed, realizing the closed-loop tracking and error minimization of the flight speed;

[0106] S43) Altitude control loop design: Input the deviation between the current altitude of the vehicle and the reference altitude into the predictive controller, the controller outputs the corresponding elevator deflection angle command, and calculates the corresponding control moment based on the deflection angle; through the angle adjustment of the control surface and the application of aerodynamic moment, the dynamic regulation of the flight altitude is realized, so that the vehicle maintains stable flight on the preset altitude trajectory.

[0107] By using the controller designed in this embodiment and the control of the existing control surface separation design to simulate the maneuvering mission situation of the reusable vehicle accelerating from 200 m / s to 300 m / s, it can be seen from Figure 2 that; compared with the existing controller, the upper bound index of the speed tracking error of the controller in this embodiment is reduced by 24.03%. Thus, it is proved that the predictive controller in this embodiment can well control the reusable vehicle to fly within a predetermined reference profile.

[0108] Through the real-time prediction of the flight state and the rolling optimization of the control quantity, this embodiment can effectively improve the robustness and control accuracy of the aircraft during mission execution, and is particularly suitable for trajectory tracking and attitude control tasks in cross-domain and multi-task flight scenarios. This embodiment realizes the precise control of the flight trajectory, especially the flight altitude, by simultaneously adjusting the sweep angle and the elevator angle of the aircraft, and is particularly suitable for the control of the aircraft in various stages such as reentry, gliding, transition, and landing, realizing the dynamic optimization and task matching of the control surface resources.

[0109] The above embodiments and the descriptions in the specification only illustrate the principles and the best embodiments of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A control method for a reusable aircraft based on control surface allocation, characterized in that It includes the following steps: S1), construct the dynamic system of the reusable aircraft; S2), construct the prediction model for the distribution of the swept wing and elevator surface; S3), design the predictive controller for high-maneuver guidance based on the coupling characteristics of the swept wing and elevator surface; S4), use the designed predictive controller to control the reusable aircraft to fly on a predetermined reference profile to achieve the tracking of speed and altitude.

2. The control method of a reusable aircraft based on rudder surface allocation according to claim 1, characterized in that: In step S1), to construct the dynamic system of the reusable aircraft, the following steps are specifically included: S11), in the ground coordinate system, establish the translational dynamic vector equation of the center of mass of the reusable aircraft: In the formula, m is the instantaneous mass of the reusable aircraft, with the unit of kg; V is the velocity vector of the reusable aircraft, with the unit of m / s; R and G are the aerodynamic force and gravity respectively, with the unit of N; S12), obtain according to the relationship between the relative derivative and the absolute derivative of the vector: In the formula, is the time derivative of the reusable vehicle with respect to the orbital coordinate system, with the unit of m / s 2 ; Ω is the angular velocity vector of the rotation of the orbital coordinate system, with the unit of rad / s; S13), obtain the components of the center-of-mass velocity vector V of the reusable aircraft on each axis of Ox2y2z2 according to the definition of the orbital coordinate system: where, V x2 , V y2 , V z2 are the components of the centroid velocity vector V of the reusable aircraft on the Ox2y2z2 axes, respectively; S14), obtain the scalar form of the dynamic equation of the translational motion of the center of mass of the reusable aircraft according to the dynamic equation: Where, t is the time; θ is the flight path angle; γ is the flight path angle; T, D, and L are the thrust, drag, and lift respectively.

3. A reusable aircraft control method based on rudder surface allocation according to claim 1, characterized in that: In step S2), in the control design, set the current moment as k, the control time domain interval as Δk, and the system predicts the control input and system response in the future N steps within this interval; among them, the control input sequence U(k) is defined as: U(k) = {u(k|k), u(k + 1|k), …, u(k + N - 1|k)}; (9) The corresponding system output prediction sequence Y(k) is: Y(k) = {y(k + 1|k), y(k + 2|k), …, y(k + N|k)}; (10) In the formula, u(k|k) represents the control input calculated based on the current system state at the time step k; the subscript k∣k represents the control input calculated under the known system state at the current moment k; y(k + 1|k) represents the predicted output at the time step k + 1.

4. A reusable aircraft control method based on rudder surface allocation according to claim 3, characterized in that: In step S2), introduce the following cost function as the optimization objective function and design the constraint conditions: where, J represents the cost function; y ref (k + j) represents the reference output trajectory at the (k + j)-th step; represents the transpose operation; Q j represents the weight matrix of the predicted output error at the j-th step; Δu(k + j - 1) = u(k + j - 1) - u(k + j - 2) represents the input difference between the (k + j - 1)-th step and the (k + j - 2)-th step; The constraint conditions are: where, u min , u max respectively represent the minimum and maximum values of the input value during the input process; u(k+j|k) represents predicting the input value at the (k + j)-th step given the k-th step; Δu min , Δu max respectively represent the minimum and maximum values of the input variable during the input process; Δu(k + j) represents the input difference at the (k + j)-th step.

5. A reusable aircraft control method based on rudder surface allocation according to claim 4, characterized in that: In step S2), by designing the following first-order response model of the control surface to reflect the dynamic behavior of the control surface, where δ(t) is the actual rudder surface angle; δ u (t) is the controller set value; τ is the time constant.

6. The control method of a reusable aircraft based on rudder surface allocation according to claim 5, wherein: In step S2), adopt the model predictive control strategy, predict and optimize the future control input sequence according to the current state of the aircraft, combine the sweep angle and elevator angle for linkage control, and consider the following in the control process: The control objective is to track the preset flight altitude or trajectory of the aircraft; The control input sequence U(k) and output sequence Y(k) depend on the future state estimation within the prediction interval N; the cost function J comprehensively considers the output error and the control variation; the controller optimization process is limited by the control amplitude and rate; the control surface channel is modeled as a first-order system, and the dynamic response is incorporated into the optimization process.

7. A reusable aircraft control method based on rudder surface allocation according to claim 6, characterized in that: In step S2), the expression of the dynamic equation of the longitudinal velocity loop of the swept wing and elevator surface for the reusable aircraft is: In the formula, is the first derivative of the velocity vector V of the reusable aircraft; is the first derivative of the flight path angle γ; T is the thrust term; F V is the measurable term related to the flight path angle; respectively represent the uncertain vector terms related to the flight path angle; Ψ V,1 and Ψ V,2 respectively represent the measurable vectors related to the velocity; S(Φ c ) represents the fuel ratio constraint; Φ c is the fuel ratio; represents the altitude derivative; F γ represents the measurable term related to the flight path angle; respectively represent the uncertain vector terms related to the flight path angle; Ψ γ,1 and Ψ γ,2 and Ψ γ,3 respectively represent the measurable vectors related to the flight path angle; α is the angle of attack; is the derivative of the angle of attack; δ c represents the swept wing; Q is the pitch rate; is the derivative of the pitch rate; ζ Q,2 respectively represent the uncertain vector terms related to the pitch rate; Ψ Q,1 and Ψ Q,2 respectively represent the measurable vectors related to the pitch rate; δ e represents the elevator deflection angle; d V and d γ and d Q are the interference terms.

8. A reusable aircraft control method based on control surface allocation according to claim 7, characterized in that: In step S2), during the altitude loop control of the reusable aircraft, the swept wings, elevator surfaces, and aerodynamic rudders are distributed in a chain-like manner, that is, when the aerodynamic rudders cannot meet the maneuverability requirements, the swept wings and elevator surfaces are triggered to deflect; and it is assumed that the thrust coefficient k Φ satisfies: where K, are respectively the maximum and minimum values of the thrust coefficient; k Φ is the thrust coefficient; δ T is the deflection angle of the swept wing and the elevator surface; The described thrust term T and fuel ratio Φ c satisfy a linear relationship therebetween: T = k Φ Φ c ; s.t. (0 ≤ Φ c ≤ 1); (7) Among them, the thrust coefficient k Φ corresponds to the ratio of the maximum thrust to the maximum fuel ratio.

9. A reusable aircraft control method based on rudder surface allocation according to claim 8, characterized in that: In step S3), the design of the high-maneuverability guidance predictive controller includes the following steps: S31), Calculate the velocity and altitude errors of the reusable vehicle; S32), Design the predictive controller for the altitude error and velocity error in a manner that meets the requirements of the Lyapunov function, i.e.: In the formula, is the derivative of the Lyapunov function; e V is the velocity error; is the reciprocal of the velocity error; is the derivative of the reference velocity; Φ c is the fuel ratio; d V is the disturbance term; respectively represent the uncertain vector terms related to velocity; Ψ V,1 , Ψ V,2 respectively represent the measurable vectors related to velocity; F V represents the measurable vector related to velocity; S33), Connect the designed predictive controller to the output end; the output end includes the control surface and the engine fuel ratio.

10. A reusable aircraft control method based on rudder surface allocation according to claim 9, characterized in that: In step S4), use the designed predictive controller to control the reusable vehicle to fly on a predetermined reference profile, specifically including the following steps: S41), Mission profile acquisition: According to the flight mission requirements, obtain the target reference altitude and velocity profile of the vehicle as the external reference input of the predictive controller; S42), Velocity control loop design: Introduce the error between the current flight velocity and the target reference velocity as the input quantity into the predictive controller; the controller predicts and optimizes the control output based on this velocity error to generate an appropriate fuel ratio command; by adjusting the fuel ratio, accelerate or decelerate the vehicle, so that the actual velocity gradually converges to the reference velocity, realizing the closed-loop tracking and error minimization of the flight velocity; S43), Altitude control loop design: Input the deviation between the current altitude of the vehicle and the reference altitude into the predictive controller, the controller outputs the corresponding elevator deflection angle command, and calculates the corresponding control moment based on the deflection angle; through the angle adjustment of the control surface and the application of aerodynamic moment, realize the dynamic regulation of the flight altitude, so that the vehicle maintains stable flight on the preset altitude trajectory.

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