Anti-interference control method and system for hypersonic flight vehicle

Abstract

The invention relates to an anti-interference control method and system for a hypersonic flight vehicle. The method comprises the following steps: constructing a control-oriented attitude system model of the hypersonic aircraft, and constructing a terminal function according to an acceleration convergence parameter, aircraft attitude system state information and error information based on the control-oriented attitude system model of the hypersonic aircraft; designing a dynamic sliding mode surface according to a terminal function and an adaptive law; a finite time controller is constructed by taking the dynamic sliding mode surface as a strategy, so that a tracking error is converged to a design value within a fixed time, and flight control input is obtained; the method comprises the following steps: constructing a fixed time fuzzy interference observer according to a fuzzy logic method and a fixed time control method based on a control-oriented attitude system model of a hypersonic aircraft, and obtaining an interference estimated value; and inputting the value into a finite time controller, and carrying out interference compensation on flight control input. The hypersonic flight vehicle attitude control method is used for hypersonic flight vehicle attitude control, and has the advantages of fast tracking speed, high tracking precision and strong robustness.

Description

Technical Field

[0001] The present application relates to the field of aircraft control technology, and in particular to a hypersonic aircraft anti-interference control method and system. Background Art

[0002] Hypersonic aircraft are important equipment for entering near-space. Thanks to bionics technology and new material technology, hypersonic variable-shape aircraft can significantly improve environmental adaptability. Through continuous shape changes, hypersonic aircraft have the ability to maintain relatively ideal aerodynamic characteristics, which enables the aircraft to obtain a larger flight envelope than traditional hypersonic aircraft. The introduction of variable shape technology not only improves the performance of hypersonic aircraft, but also brings more severe challenges. Nonlinearity, strong coupling, multi-mode, and susceptibility to interference are more severe in hypersonic variable-shape aircraft. Therefore, it is very necessary to study high-performance attitude controllers for hypersonic variable-shape aircraft. Summary of the invention

[0003] Based on this, it is necessary to provide a hypersonic aircraft anti-interference control method and system that can improve control accuracy and eliminate interference in response to the above technical problems. The method is suitable for hypersonic aircraft attitude control, and obtains flight control input through a dynamic sliding surface. At the same time, a fixed-time fuzzy interference observer is used to obtain interference estimation values ​​to compensate for the flight control input to eliminate interference. This effectively solves the problem of difficult high-precision control of the attitude of hypersonic deformable aircraft. It has great engineering significance and has the effects of faster tracking speed, higher tracking accuracy and stronger robustness.

[0004] In one embodiment, if Figure 1 As shown, a hypersonic aircraft anti-interference control method is provided, the method comprising:

[0005] Constructing a control-oriented attitude system model of a hypersonic aircraft, and constructing a terminal function based on the attitude system model according to acceleration convergence parameters, aircraft attitude system state information and error information;

[0006] A dynamic sliding surface is designed according to the terminal function and the adaptive law; a finite time controller is constructed with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time, and a flight control input is obtained; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding surface;

[0007] Based on the attitude system model, a fixed-time fuzzy disturbance observer is constructed according to a fuzzy logic method and a fixed-time control method to obtain a disturbance estimation value;

[0008] The disturbance estimation value is input into the finite time controller to perform disturbance compensation on the flight control input.

[0009] In one embodiment, the hypersonic vehicle control-oriented attitude system model is constructed according to the hypersonic vehicle attitude dynamics model, and is expressed as:

[0010]

[0011] in,

[0012]

[0013]

[0014]

[0015]

[0016] Where x1=[α β γ V ] represents the attitude angle; x2=[ω z ω y ω x ] represents the attitude angular velocity; u=[δ z δ y δ x ] indicates rudder deviation; Δ i1 Represents the aircraft modeling error; Δ i2 represents the external disturbance during the flight, i=1,2; L, D, N represent lift, drag, and lateral force respectively; V, m, g represent the flight speed, mass of the hypersonic vehicle, and gravitational acceleration respectively; I x ,I y ,I z represents the three-axis moment of inertia; θ represents the track angle; q represents the dynamic pressure; They are respectively expressed as the pitch moment coefficient related to the pitch rudder deflection angle, the yaw moment coefficient term related to the yaw rudder deflection angle, and the roll moment coefficient term related to the roll rudder deflection angle; S0 is the reference area; α is the vector composed of the angle of attack α=[1 α α 3 ] T , β mx =β; is the pitching moment coefficient term related to α; is the yaw moment coefficient term related to the sideslip angle; is the rolling moment coefficient term related to the roll angle.

[0017] In one embodiment, the terminal function construction process is:

[0018] Select Tracking Error:

[0019] z=x1-x c =[z1 z2 z3] T ;

[0020] Auxiliary tracking error design:

[0021] e=c A z;

[0022] c A =diag(c A1 c A2 c A3 );

[0023] c Aj =[(1-b Aj )η Aj +b Aj ] -1 ;

[0024] Among them, b Aj To accelerate the convergence coefficient, 0<b Aj <1;c A represents the accelerated convergence parameter; c Aj The value range is η Aj =exp(-λ Aj t) is an exponential function; λ Aj is a positive constant, j = 1, 2, 3; x c Indicates a reference instruction;

[0025] Construct terminal function:

[0026]

[0027] Among them, the terminal function p is in the interval [0,T f ] is bounded, T f is the time it takes for the terminal function to converge to 0; a 1j 、a 2j 、a 3j is a positive constant; t represents the flight time.

[0028] In one embodiment, the inner sliding surface is designed according to the terminal function, the acceleration convergence parameter and the real-time state motion information of the hypersonic aircraft, and the inner sliding surface is expressed as:

[0029] s(t)=ep(t);

[0030] Where e represents the auxiliary tracking error and p(t) represents the terminal function.

[0031] In one embodiment, the outer sliding surface is designed according to the adaptive law, the inner sliding surface and the derivative function of the inner sliding surface, which is expressed as:

[0032]

[0033] in:

[0034]

[0035] c si =diag(c si1 c si2 c si3 ),i=1,2,3;

[0036] Among them, κ sj 、c sij are all positive numbers; sj is the adaptive parameter; s j Represents the jth element of the inner sliding surface.

[0037] In one embodiment, a finite time controller is constructed using the dynamic sliding surface as a strategy, including:

[0038] The dynamic sliding surface composed of the inner sliding surface and the outer sliding surface is derived and expanded to obtain a finite time controller. The design process is as follows:

[0039]

[0040]

[0041]

[0042]

[0043] The equivalent controller design is:

[0044]

[0045] The reaching law is designed as:

[0046]

[0047]

[0048] Where: κσ i , cσ ij , i=1,2,3,j=1,2,3,4 are normal numbers;

[0049] Definition C σ1 =c σ1 +c σ2 ||s|| and Cσ2 =c σ3 +c σ4 ||s||, we can get the finite time controller:

[0050]

[0051] Define the vector ξ s =[ξ s1 ξ s2 ξ s3 ] T , σ =[ξ σ1 ξ σ2 ξ σ3 ] T , κ s =[κ s1 κ s2 κ s3 ] T and κ σ =[κ σ1 κ σ2 κ σ3 ] T , the adaptive law is designed as:

[0052]

[0053]

[0054] in, represents the interference estimate; k 1j , k 2j , k 3j All are coefficients; operators represents the Hadamard product; μ σi ,μ si ,i=1,2,3 are normal numbers.

[0055] In one embodiment, based on the attitude system model, a fixed-time fuzzy disturbance observer is constructed according to a fuzzy logic method and a fixed-time control method, including:

[0056] The attitude system model is simplified as follows:

[0057]

[0058] According to the fixed time control method, x 1j Design a fixed-time fuzzy disturbance observer as:

[0059]

[0060]

[0061]

[0062] According to the fixed time control method, x 2j Design a fixed-time fuzzy disturbance observer as:

[0063]

[0064]

[0065]

[0066] in, Represents the derivative of the jth element of the state quantity x1; represents the derivative of the jth element of the state quantity x2; f 1j 、f 2j represents the jth element of nonlinear functions f1 and f2; g 2j represents the jth element of the nonlinear function g2; u j represents the jth element of the control quantity u; d 1j ,d 2j Indicates the actual interference d1 and d2 jth element; η>0, ρ0>0 are coefficients; 0<r i <1 indicates the disturbance observer design parameters; λ 1,kj >0, k=1, 2, 3 are all coefficients; T e represents the convergence time of adjustable disturbance observation error;

[0067] Based on the universal approximation capability of the fuzzy logic method, the interference estimate is calculated:

[0068]

[0069] Where i = 1, 2, j = 1, 2, 3; is θ ij The optimal value of ; ε is the estimation error;

[0070] express The estimated value of interference can be expressed as:

[0071]

[0072]

[0073] The adaptive law of the disturbance observer is designed as:

[0074]

[0075] Among them, γij and l ij is a positive parameter; ψ(x) represents the fuzzy basis function.

[0076] A hypersonic aircraft anti-interference control system, the system comprising:

[0077] A model building module is used to build a control-oriented attitude system model of a hypersonic aircraft, and based on the attitude system model, build a terminal function according to acceleration convergence parameters, aircraft attitude system state information and error information;

[0078] A finite time controller construction module is used to design a dynamic sliding surface according to the terminal function and the adaptive law; a finite time controller is constructed with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time, and a flight control input is obtained; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding surface;

[0079] A fixed-time fuzzy disturbance observer building module is used to build a fixed-time fuzzy disturbance observer based on the attitude system model according to a fuzzy logic method and a fixed-time control method to obtain a disturbance estimation value;

[0080] The interference compensation module is used to input the interference estimation value into the finite time controller to perform interference compensation on the flight control input.

[0081] Compared with the prior art, the anti-interference control method and system for hypersonic aircraft provided by the present invention have the following effects:

[0082] 1. Different from the traditional internal and external layered design, this application uses a dynamic sliding surface designed based on the terminal function of the accelerated convergence parameter, the state information of the aircraft attitude system and the error information, and the adaptive technology to directly obtain the control input, which can ensure finite time convergence and better tracking accuracy;

[0083] 2. Using fuzzy logic method and fixed-time control method to construct a fixed-time fuzzy disturbance observer can obtain accurate disturbance estimation and compensate it to the finite-time controller to eliminate the impact of disturbance.

[0084] 3. The present invention is used for attitude control of hypersonic aircraft, has great engineering application significance, effectively solves the problem of high-performance attitude control of hypersonic aircraft, and has faster tracking speed, higher tracking accuracy and stronger robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 is a flow chart of an anti-interference control method for a hypersonic aircraft in one embodiment;

[0086] Figure 2 A tracking curve diagram of the attitude angle to the instruction in the simulation example 1 in an embodiment;

[0087] Figure 3 A curve diagram showing the change of angular velocity in a simulation example 1 in an embodiment;

[0088] Figure 4 is a curve diagram of the change of the rudder deflection angle and the deformation rate in a simulation example 1 in an embodiment;

[0089] Figure 5 is a curve diagram of the change of the attitude angle in the simulation example 2 in one embodiment;

[0090] Figure 6 A graph showing a change in attitude angular rate in a simulation example 2 in an embodiment;

[0091] Figure 7 is a curve diagram of the change of the rudder deflection angle in the simulation example 2 in one embodiment;

[0092] Figure 8 It is an observation curve diagram of the fixed-time fuzzy interference observer to the non-matching interference in the simulation example 2 in one embodiment;

[0093] Fig. 9 It is an observation curve diagram of the matching interference of the fixed-time fuzzy interference observer in the simulation example 2 in one embodiment.

[0094] Fig.10 is a curve diagram of the change of the attitude angle in the simulation example 3 in one embodiment;

[0095] Fig.11 A graph showing a change in attitude angular rate in a simulation example 3 in an embodiment;

[0096] Fig.12 is a curve diagram of the change of the rudder deflection angle in the simulation example 3 in one embodiment;

[0097] Fig.13 Schematic diagram of a hypersonic aircraft anti-interference control system module in one embodiment. DETAILED DESCRIPTION

[0098] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0099] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0100] In one embodiment, Figure 1 As shown, a hypersonic vehicle anti-interference control method is provided, comprising the following steps:

[0101] Step 102, constructing a control-oriented attitude system model of a hypersonic aircraft, and based on the attitude system model, constructing a terminal function according to acceleration convergence parameters, aircraft attitude system state information and error information.

[0102] Specifically, firstly, the attitude system model is constructed based on the attitude dynamics model of the hypersonic aircraft. According to the attitude system model, the state equation, error model and initial value for the finite time controller design are determined. And the terminal function is constructed according to the acceleration convergence parameter, the state information and initial error value of the aircraft attitude system, the first-order derivative function of the state and error, the initial value of the second-order derivative function and the aircraft flight time (flight control system operation time).

[0103] More specifically, the motion equation of the attitude system of a hypersonic vehicle is expressed as:

[0104]

[0105] Among them, α, β, γ V Respectively represent the angle of attack, sideslip angle, and roll angle; ω x ,ω y ,ω z M represents the roll, yaw and pitch angular velocity respectively; L, D and N represent the lift, drag and lateral force respectively; V, m and g represent the flight speed, mass of the hypersonic vehicle and gravitational acceleration respectively. x ,M y ,M z Respectively represent the rolling, yaw and pitching moments; M sx ,M sy ,M sz They represent the additional moments of the three-axis deformation caused by the corresponding deformation; I x ,I y ,I z represents the three-axis moment of inertia; θ represents the track angle.

[0106] The attitude system model is expressed as:

[0107]

[0108] in,

[0109]

[0110]

[0111]

[0112]

[0113] Where x1=[α β γ V ] represents the attitude angle; x2=[ω z ω y ω x ] represents the attitude angular velocity; u=[δ z δ y δ x ] indicates rudder deviation; Δ i1 Represents the aircraft modeling error; Δ i2 represents the external disturbance during the flight, i=1,2; L, D, N represent lift, drag, and lateral force respectively; V, m, g represent the flight speed, mass of the hypersonic vehicle, and gravitational acceleration respectively; I x ,I y ,I z represents the three-axis moment of inertia; θ represents the track angle; q represents the dynamic pressure; They are respectively expressed as the pitch moment coefficient related to the pitch rudder deflection angle, the yaw moment coefficient term related to the yaw rudder deflection angle, and the roll moment coefficient term related to the roll rudder deflection angle; S0 is the reference area; α is the vector composed of the angle of attack α=[1 α α 3 ] T , β mx =β; is the pitching moment coefficient term related to α; is the yaw moment coefficient term related to the sideslip angle; is the rolling moment coefficient term related to the roll angle.

[0114] It is worth noting that the present invention converts the complex terms in the motion equation of the attitude system of the hypersonic aircraft into and the additional moment caused by the deformation are combined into Δ 21 At the same time, in the subsequent derivation, the total interference can be expressed as d i =Δ i1 +Δ i2 ,i=1,2.

[0115] The established attitude system model is different from the existing double-integral model or strict feedback form. It merges g1 into f1. When using the three-axis angular velocity information, it reduces the complexity of the second-order derivative of the sliding surface and avoids the problem of stronger nonlinearity caused by the multiplication of multiple nonlinear functions. It helps to realize a simple and clear mathematical process for designing a finite-time controller and improve the tracking speed.

[0116] Select the tracking error as:

[0117] z=x1-x c =[z1 z2 zx] T ;

[0118] Auxiliary tracking error design:

[0119] e=c A z;

[0120] c A =diag(c A1 c A2 c A3 );

[0121] c Aj =[(1-b Aj )η Aj +b Aj ] -1 ;

[0122] Among them, b Aj To accelerate the convergence coefficient, 0<b Aj <1;c A represents the accelerated convergence parameter; c Aj The value range is η Aj =exp(-λ Aj t) is an exponential function; λ Aj is a positive constant, j = 1, 2, 3; x c Indicates a reference instruction;

[0123] Construct terminal function:

[0124]

[0125] Among them, the terminal function p is in the interval [0,T f ] is bounded, T f is the time it takes for the terminal function to converge to 0; a 1j 、a 2j 、a 3j is a positive constant; t represents the flight time. At the same time, considering the need for global boundedness, the design function satisfies e(0)=p(0), If time t>Tf , the terminal function p also satisfies p(t)=0,

[0126] It is worth noting that the designed acceleration convergence parameter c A It can increase from 1 to a finite value over time. According to the relationship between the auxiliary tracking error and the real tracking error, it can strengthen the control ability of the tracking error at each stage, achieve a smaller error in the entire convergence process, and obtain an aircraft angle tracking curve that is closer to the angle command.

[0127] Step 104, designing a dynamic sliding surface according to the terminal function and the adaptive law; constructing a finite time controller with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time, and obtains the flight control input; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding surface.

[0128] Specifically, the inner sliding surface is first constructed according to the terminal function, the acceleration convergence parameter and the real-time state motion information of the hypersonic aircraft. The inner sliding surface is expressed as:

[0129] s(t)=ep(t);

[0130] Where e represents the auxiliary tracking error and p(t) represents the terminal function.

[0131] Then, the outer sliding surface is constructed according to the adaptive law, the inner sliding surface and the derivative function of the inner sliding surface. The outer sliding surface is expressed as:

[0132]

[0133] in:

[0134]

[0135] c si =diag(c si1 c si2 c si3 ),i=1,2,3;

[0136] Among them, κ sj 、c sij are all positive numbers; sj is the adaptive parameter; s j Represents the jth element of the inner sliding surface.

[0137] The dynamic sliding surface is composed of the inner sliding surface and the outer sliding surface. By taking the derivative of the dynamic sliding surface, a finite time controller is obtained. The design process is as follows:

[0138]

[0139]

[0140]

[0141]

[0142] The equivalent controller design is:

[0143]

[0144] The reaching law is designed as:

[0145]

[0146]

[0147] Where: κσ i , cσ ij , i=1,2,3,j=1,2,3,4 are positive numbers, and the parameters satisfy

[0148] Definition C σ1 =c σ1 +c σ2 ||s|| and C σ2 =c σ3 +c σ4 ||s||, we can get the finite time controller:

[0149]

[0150] Define the vector ξ s =[ξ s1 ξ s2 ξ s3 ] T , σ =[ξ σ1 ξ σ2 ξ σ3 ] T , κ s =[κ s1 κ s2 κ s3 ] T and κ σ =[κ σ1 κ σ2 κ σ3 ] T , the adaptive law is designed as:

[0151]

[0152]

[0153] in, represents the interference estimate; k 1j , k 2j , k 3j All are coefficients; operators represents the Hadamard product; μ σi ,μ si ,i=1,2,3 are normal numbers.

[0154] It is worth noting that the dynamic sliding surface can directly obtain the control input from the tracking error without the need for more complicated methods such as command filters or dynamic inversion. By introducing a terminal function designed based on the accelerated convergence parameter into the inner sliding surface, the tracking error will be rapidly reduced. f The inner and outer sliding surfaces converge to zero, achieving designable finite time convergence. The outer sliding surface is constructed using the adaptive law to obtain a finite time controller, avoiding the traditional lengthy hierarchical design of attitude angle and angular velocity. The dynamic sliding surface composed of the inner sliding surface and the outer sliding surface can not only meet the finite time convergence, but also directly obtain the finite time controller. It has obvious advantages in applying it to hypersonic variable shape aircraft. In order to further improve the tracking performance, the accelerated convergence parameters that promote performance convergence can be well adapted to the dynamic sliding surface to improve the overall performance of the closed-loop system.

[0155] Step 106 : Based on the attitude system model, a fixed-time fuzzy disturbance observer is constructed according to a fuzzy logic method and a fixed-time control method to obtain a disturbance estimation value.

[0156] Specifically, the attitude system model is simplified first:

[0157]

[0158] According to the fixed time control method, x 1j Design a fixed-time fuzzy disturbance observer as:

[0159]

[0160]

[0161]

[0162] According to the fixed time control method, x 2j Design a fixed-time fuzzy disturbance observer as:

[0163]

[0164]

[0165]

[0166] in, Represents the derivative of the jth element of the state quantity x1; represents the derivative of the jth element of the state quantity x2; f 1j 、f 2j represents the jth element of nonlinear functions f1 and f2; g 2j represents the jth element of the nonlinear function g2; u j represents the jth element of the control quantity u; d 1j ,d 2j Indicates the actual interference d1 and d2 jth element; η>0, ρ0>0 are coefficients; 0<r i <1 indicates the disturbance observer design parameters;

[0167] λ 1,kj >0, k=1, 2, 3 are all coefficients; T e Represents the convergence time of the adjustable disturbance observation error.

[0168] Based on the universal approximation capability of the fuzzy logic method, the interference estimate is calculated:

[0169]

[0170] Where i = 1, 2, j = 1, 2, 3; is θ ij The optimal value of ; ε is the estimation error;

[0171] express The estimated value of interference can be expressed as:

[0172]

[0173]

[0174] The adaptive law of the disturbance observer is designed as:

[0175]

[0176] Among them, γ ij and l ij is a positive parameter; ψ(x) represents the fuzzy basis function.

[0177] The purpose of anti-interference technology is to eliminate the influence of interference and uncertainty encountered by hypersonic variable-shape aircraft during flight. Fixed-time fuzzy interference observer is a very effective application of anti-interference technology. Compared with general nonlinear interference observers, anti-interference technology using intelligent control technology has more obvious advantages. It often has better observation performance. Combining fuzzy logic system with fixed-time control technology, it is possible to design an interference observer with excellent performance, which can effectively compensate and estimate the interference encountered by hypersonic variable-shape aircraft. Fixed-time fuzzy interference observer has the characteristics of fixed-time convergence, and its correlation coefficient will continue to tend to the ideal parameters. At the same time, using fixed-time convergence, the interference observation performance is not affected by the initial value of the hypersonic aircraft, and has better robustness, which has obvious advantages.

[0178] Compared with the traditional nonlinear disturbance observer, the fuzzy disturbance observer designed in this invention has three major advantages:

[0179] 1) Fuzzy logic system is a universal function approximator that can approximate any continuous function and has ideal interference approximation capability;

[0180] 2) The fuzzy logic system uses adaptive laws to make the weight coefficient always tend to the optimal value, reach the optimal value and maintain it at the optimal value, which makes the fuzzy interference observer have a wider range of interference estimation application scenarios and can adapt to more severe and complex interference scenarios;

[0181] 3) The observation error will converge to zero in a fixed time. By introducing the fixed time control technology, fast and designable observation error convergence can be achieved to complete the high-performance fuzzy interference estimation task.

[0182] Step 108, input the disturbance estimation value into the finite time controller to perform disturbance compensation on the flight control input.

[0183] Specifically, the complete hypersonic aircraft attitude controller consists of a finite time controller and a fixed time fuzzy disturbance observer. By obtaining the state information and error information of the aircraft in real time and inputting them into the fixed time fuzzy disturbance observer, the required disturbance estimation value is introduced into the finite time controller to obtain the attitude control input. After the attitude control input is input into the hypersonic aircraft, it can ensure that the aircraft attitude quickly tracks the preset attitude angle instruction, complete the rapid tracking and stabilization of the aircraft attitude system, and at the same time improve the control accuracy and anti-interference performance of the aircraft attitude, which effectively solves the problem of high-precision control difficulties in the attitude of hypersonic deformable aircraft.

[0184] In the above-mentioned anti-interference control method for hypersonic aircraft, a control-oriented attitude system model of hypersonic aircraft is constructed based on the attitude dynamics model of hypersonic aircraft; according to the attitude system model, the state equation, error model and initial value used for the design of the attitude controller of hypersonic aircraft are determined; and based on the attitude system model, a terminal function is constructed according to the acceleration convergence parameter, the state information of the aircraft attitude system and the error information; a dynamic sliding surface is designed according to the terminal function and the adaptive law; a finite time controller is constructed with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time, and the flight control input is obtained; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, and the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding mode; at the same time, based on the attitude system model, a fixed time fuzzy interference observer is constructed according to the fuzzy logic method and the fixed time control method to obtain the interference estimation value; finally, the interference estimation value is input into the finite time controller, and the flight control input is interference compensated to eliminate the influence of the interference. This method is suitable for attitude control of hypersonic aircraft, has great engineering application significance, and effectively solves the problem of high-performance attitude control of hypersonic aircraft. It has faster tracking speed, higher tracking accuracy and stronger robustness.

[0185] In one of the embodiments, in order to verify and illustrate the effectiveness and superiority of the present invention, three simulation verifications are provided. Among them, simulation example 1 verifies the effectiveness of the designed fuzzy interference control method; simulation example 2 verifies and compares the effectiveness and superiority of the present invention in anti-interference performance; simulation example 3 verifies and illustrates that the control method designed by the present invention still has good tracking performance in the presence of parameter deviation. The following is a detailed description of the embodiments to which the present method is applied.

[0186] For all simulation cases, the controller parameters are selected as follows:

[0187] The coefficient settings for the terminal function are shown in Table 1:

[0188] Table 1 Terminal function coefficients and values

[0189]

[0190] The coefficient settings for the sliding mode controller are shown in Table 2:

[0191] Table 2 Sliding mode controller coefficients and values

[0192]

[0193] The coefficient settings for the acceleration parameters are shown in Table 3:

[0194] Table 3 Coefficients and values ​​of acceleration parameters

[0195]

[0196] The coefficient settings for the fixed-time fuzzy disturbance observer are shown in Table 4:

[0197] Table 4 Coefficients and values ​​of disturbance observer

[0198]

[0199] The initial value settings of the aircraft are shown in Table 5:

[0200] Table 5 Initial state and value

[0201]

[0202] (1) Simulation example settings

[0203] The present invention sets up Example 1 mainly to verify the effectiveness of the controller. Therefore, an angle command that changes with time is used to input the controller calculation equation to obtain the control input. At the same time, the aircraft attitude model is controlled according to the set initial value and the flight altitude and speed to obtain a real-time state response. The curve difference between the state response and the angle command is observed and compared to verify the effectiveness of the method designed by the present invention and the rationality of this embodiment.

[0204] In this example, the aircraft angle command is set as:

[0205]

[0206] β c =0°,0<t<20

[0207]

[0208] In order to make the command smoother, the following second-order servo system is used to generate the command:

[0209]

[0210] The second simulation example is to verify the effectiveness and superiority of the proposed fuzzy anti-interference control method in dealing with matching interference and non-matching interference. Therefore, a step angle command is used to input the controller calculation equation to obtain the control input. At the same time, the aircraft attitude model is controlled according to the set initial value and the flight altitude and speed to obtain a real-time state response. External interference that changes over time is added during the flight. The curve difference between the state response and the angle command and the difference between the actual interference and the output value of the interference observer are observed and compared to verify the excellent performance of the method designed by the present invention in anti-interference.

[0211] In this embodiment, the aircraft angle command is set as:

[0212] α c =8°

[0213] β c =0°

[0214] γ Vc =15°

[0215] The second-order servo system used to generate commands is the same as that of Simulation Example 1.

[0216] The external interference added during the flight of the aircraft is:

[0217]

[0218] d2=10d1

[0219] The third simulation example is to verify the effectiveness and superiority of the proposed fuzzy anti-interference control method in stabilizing the aircraft attitude under the condition of parameter deviation. This example uses a step angle command and inputs it into the controller calculation equation to obtain the control input. At the same time, the aircraft attitude model is controlled according to the set initial value and the flight altitude and speed to obtain a real-time state response. Parameter deviation is introduced during the flight of the aircraft. The curve difference between the state response and the angle command is observed and compared to verify the excellent performance of the method designed by the present invention in resisting parameter deviation.

[0220] In this embodiment, the aircraft angle command is set as:

[0221] α c =8°

[0222] β c =0°

[0223] γ Vc =15°

[0224] The second-order servo system used to generate commands is the same as that of Simulation Example 1.

[0225] The parameter deviation added during the flight of the aircraft is shown in Table 6

[0226] Table 6 Parameter pull-off setting

[0227]

[0228] (2) Analysis of simulation results

[0229] 2. Results Analysis

[0230] The simulation results of simulation examples 1 to 3 are shown in Figure 2-Figure 12In the figure, Command represents the attitude angle tracking command, that is, the command of the angle of attack, sideslip angle and roll angle; Angles represents the actual attitude angle response; times(s) represents the flight simulation time and its unit is seconds; deg represents the angle unit is degree; Actual disturbance represents the actual disturbance; Estimated disturbance represents the estimated disturbance, nominal represents no aerodynamic pull, positive represents positive aerodynamic pull, and negative represents negative aerodynamic pull.

[0231] The simulation results of simulation example 1 are as follows: Figure 2-Figure 4 shown. Figure 2-Figure 4 The simulation example used in the present invention shows the changes in angle, angular velocity and control surface under time-varying instructions. Figure 2 The results shown in the figure show that the fuzzy anti-interference control of the hypersonic variable-shape aircraft designed in the present invention is effective, the attitude angle of the aircraft can track the angle instruction within 2 seconds, and the tracking error is relatively ideal. Figure 3 It shows the change of angular velocity during the flight of the aircraft. Figure 4 The changes in the control surfaces and deformation rates of the aircraft during flight are shown. The pitch rudder will change accordingly with the change in deformation rate, because the deformation has a more obvious effect on the pitch channel of the aircraft.

[0232] The simulation results of simulation example 2 are as follows: Figure 5-Figure 9 As shown. Figure 5 and 6 The simulation example designed by the present invention verifies that the anti-interference control method (ADTSMC-FDO) designed by the present invention can still maintain high tracking accuracy when the aircraft is subjected to time-varying non-matching and matching interference. Compared with the traditional terminal sliding mode control method (DTSMC), it is less affected and more robust. By comparing the performance of the controller before the introduction of the disturbance observer (ADTSMC), it can be seen that the controller itself has strong robustness, and the fuzzy jammer further improves the anti-interference performance. Figure 7 The changes of the control surface in simulation example 2 are shown, and the deformation rate setting is the same as that in simulation example 1. Figure 8 and Fig. 9 The excellent performance of the disturbance observer designed by this method is demonstrated. Whether it is matched disturbance or non-matched disturbance, the fixed-time fuzzy disturbance observer can make fast and accurate estimates and compensate the estimated value into the controller to eliminate the influence of the disturbance on attitude control. The results are combined with Figure 5 and Figure 6 Can be verified.

[0233] The results of simulation example 3 are as follows Figure 10-12 As shown. Fig.10After applying the designed fuzzy anti-interference controller, the control influence of negative parameter deviation on the aircraft can be eliminated ideally. In the stage of rapidly increasing the angle, the positive parameter deviation has a certain influence on the tracking response process, but this influence is quickly reduced within 2 seconds. Finally, regardless of positive or negative deviation, the angle of the aircraft can track the instruction ideally within 2 seconds. Fig.11 The change of angular velocity under different parameter pulling conditions is shown. Fig.12 The corresponding controller changes are shown, and the deformation rate is set the same as in simulation example 1.

[0234] In order to better realize the attitude control task during the flight of hypersonic aircraft, the present invention designs a finite time adaptive sliding mode control method based on terminal sliding mode based on dynamic sliding mode control method, which can obtain relatively ideal tracking performance. Based on the fixed time control method and fuzzy logic system, a fuzzy disturbance observer is designed, which can effectively handle external interference and parameter deviation, improve the mission adaptability of the aircraft, and verify the effectiveness of this method in aircraft attitude control. At the same time, it provides the application of intelligent control technology in aircraft anti-interference control, which helps the development of intelligent control of hypersonic aircraft.

[0235] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0236] In one embodiment, Fig.13 As shown, a hypersonic aircraft anti-interference control system is provided, which includes: a model building module, a finite time controller building module, a fixed time fuzzy interference observer building module, and an interference compensation module.

[0237] The model building module is used to build a control-oriented attitude system model of a hypersonic aircraft, and based on the attitude system model, build a terminal function according to the acceleration convergence parameters, the aircraft attitude system state information and error information.

[0238] A finite time controller construction module is used to design a dynamic sliding surface according to the terminal function and the adaptive law; a finite time controller is constructed with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time and obtains the flight control input; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding surface.

[0239] The fixed-time fuzzy disturbance observer building module is used to build a fixed-time fuzzy disturbance observer based on the attitude system model according to the fuzzy logic method and the fixed-time control method to obtain the disturbance estimation value.

[0240] The interference compensation module is used to input the interference estimation value into the finite time controller to perform interference compensation on the flight control input.

[0241] For the specific definition of the anti-interference control system of a hypersonic aircraft, please refer to the definition of the anti-interference control method of a hypersonic aircraft above, which will not be repeated here. Each module in the above-mentioned anti-interference control system of a hypersonic aircraft can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0242] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0243] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0244] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A hypersonic vehicle anti-interference control method, characterized in that: The method comprises: Constructing a control-oriented attitude system model of a hypersonic aircraft, and constructing a terminal function based on the attitude system model according to acceleration convergence parameters, aircraft attitude system state information and error information; A dynamic sliding surface is designed according to the terminal function and the adaptive law; a finite time controller is constructed with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time, and a flight control input is obtained; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding surface; Based on the attitude system model, a fixed-time fuzzy disturbance observer is constructed according to a fuzzy logic method and a fixed-time control method to obtain a disturbance estimation value; The disturbance estimation value is input into the finite time controller to perform disturbance compensation on the flight control input.

2. The anti-interference control method for a hypersonic vehicle according to claim 1, characterized in that: The control-oriented attitude system model of the hypersonic aircraft is constructed according to the attitude dynamics model of the hypersonic aircraft and is expressed as: in, Where x1=[α β γ V ] represents the attitude angle; x2=[ω z ω y ω x ] represents the attitude angular velocity; u=[δ z δ y δ x ] indicates rudder deviation; Δ i1 Represents the aircraft modeling error; Δ i2 represents the external disturbance during the flight, i=1,2; L, D, N represent lift, drag, and lateral force respectively; V, m, g represent the flight speed, mass of the hypersonic vehicle, and gravitational acceleration respectively; I x ,I y ,I z represents the three-axis moment of inertia; θ represents the track angle; q represents the dynamic pressure; They are respectively expressed as the pitch moment coefficient related to the pitch rudder deflection angle, the yaw moment coefficient term related to the yaw rudder deflection angle, and the roll moment coefficient term related to the roll rudder deflection angle; S0 is the reference area; α is the vector composed of the angle of attack α=[1 α α 3 ] T , β mx =β; is the pitching moment coefficient term related to α; is the yaw moment coefficient term related to the sideslip angle; is the rolling moment coefficient term related to the rolling angle.

3. The anti-interference control method for a hypersonic vehicle according to claim 2, characterized in that: The terminal function construction process is as follows: Select Tracking Error: z=x1-x c [z1 z2 z3] T 4 Auxiliary tracking error design: e=c A with; c A =diag(c A1 c A2 c A3 ); c Aj =[(1-b Aj )or Aj +b Aj ] -1 ; Among them, b Aj To accelerate the convergence coefficient, 0<b Aj <1;c A represents the accelerated convergence parameter; c Aj The value range is η Aj =exp(-λ Aj t) is an exponential function; λ Aj is a positive constant, j = 1, 2, 3; x c Indicates a reference instruction; Construct terminal function: Among them, the terminal function p is in the interval [0,T f ] is bounded, T f is the time it takes for the terminal function to converge to 0; a 1j 、a 2j 、a 3j is a positive constant; t represents the flight time.

4. The anti-interference control method for a hypersonic vehicle according to claim 3, characterized in that: The inner sliding surface is designed according to the terminal function, the acceleration convergence parameter and the real-time state motion information of the hypersonic aircraft. The inner sliding surface is expressed as: s(t)=ep(t); Where e represents the auxiliary tracking error and p(t) represents the terminal function.

5. The anti-interference control method for a hypersonic vehicle according to claim 4, characterized in that: The outer sliding surface is designed according to the adaptive law, the inner sliding surface and the derivative function of the inner sliding surface, which can be expressed as: in: c si =diag(c si1 c si2 c si3 ),i=1,2,3; Among them, κ sj 、c sij are all positive numbers; sj is the adaptive parameter; s j Represents the jth element of the inner sliding surface.

6. The anti-interference control method for a hypersonic vehicle according to claim 4, characterized in that: A finite time controller is constructed using the dynamic sliding surface as a strategy, including: The dynamic sliding surface composed of the inner sliding surface and the outer sliding surface is derived and expanded to obtain a finite time controller. The design process is as follows: The equivalent controller design is: The reaching law is designed as: Where: κσ i , cσ ij , i=1,2,3,j=1,2,3,4 are normal numbers; Definition C σ1 =c σ1 +c σ2 ||s|| and C σ2 =c σ3 +c σ4 ||s||, we can get the finite time controller: definition vectorx s =[ξ s1 x s2 x s3 ] T ,x σ =[ξ σ1 x σ2 x σ3 ] T 、k s =[k s1 k s2 k s3 ] T Japanese σ =[k σ1 k σ2 k σ3 ] T , self-adaptive design for: in, represents the interference estimate; k 1j , k 2j , k 3j All are coefficients; operators represents the Hadamard product; μ σi ,μ si ,i=1,2,3 are normal numbers.

7. The anti-interference control method for a hypersonic vehicle according to any one of claims 1 to 6, characterized in that: Based on the attitude system model, a fixed-time fuzzy disturbance observer is constructed according to a fuzzy logic method and a fixed-time control method, including: The attitude system model is simplified as follows: According to the fixed time control method, x 1j Design a fixed-time fuzzy disturbance observer as: According to the fixed time control method, x 2j Design a fixed-time fuzzy disturbance observer as: in, Represents the derivative of the jth element of the state quantity x1; represents the derivative of the jth element of the state quantity x2; f 1j 、f 2j represents the jth element of nonlinear functions f1 and f2; g 2j represents the jth element of the nonlinear function g2; u j represents the jth element of the control quantity u; d 1j ,d 2j Indicates the actual interference d1 and d2 jth element; η>0, ρ0>0 are coefficients; 0<r i <1 indicates the disturbance observer design parameters; λ 1,kj >0, k=1, 2, 3 are all coefficients; T e represents the convergence time of adjustable disturbance observation error; Based on the universal approximation capability of the fuzzy logic method, the interference estimate is calculated: Where i = 1, 2, j = 1, 2, 3; is θ ij The optimal value of ; ε is the estimation error; express The estimated value of interference can be expressed as: The adaptive law of the disturbance observer is designed as: Among them, γ ij and l ij is a positive parameter; ψ(x) represents the fuzzy basis function.

8. A hypersonic vehicle anti-interference control system, characterized in that: The system comprises: A model building module is used to build a control-oriented attitude system model of a hypersonic aircraft, and based on the attitude system model, build a terminal function according to acceleration convergence parameters, aircraft attitude system state information and error information; A finite time controller construction module is used to design a dynamic sliding surface according to the terminal function and the adaptive law; a finite time controller is constructed with the dynamic sliding surface as a strategy, so that the tracking error converges to the design value within a fixed time, and a flight control input is obtained; wherein the dynamic sliding surface includes an inner sliding surface and an outer sliding surface, the tracking error is converged to the design value within a fixed time through the inner sliding surface, and adaptive convergence is performed through the outer sliding surface; A fixed-time fuzzy disturbance observer building module is used to build a fixed-time fuzzy disturbance observer based on the attitude system model according to a fuzzy logic method and a fixed-time control method to obtain a disturbance estimation value; The interference compensation module is used to input the interference estimation value into the finite time controller to perform interference compensation on the flight control input.

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