Event-triggered finite-time control method and system for hypersonic vehicle

Abstract

The application relates to a kind of event-triggered hypersonic vehicle finite time control method and system, by constructing the attitude system model of hypersonic vehicle facing control, event-triggered strategy is designed, and internal dynamic variable matching convergence characteristic and sliding mode variable is established in event-triggered strategy;According to angle tracking error and approach law, a fast finite time controller is constructed by using fast finite time control method;According to event-triggered strategy and fast finite time controller, event-triggered finite time controller is constructed;Real-time error information of aircraft is obtained, and the error information is input into event-triggered finite time controller for calculation to obtain attitude control input;The attitude angle of aircraft is adjusted and controlled through attitude control input, the problem of designing strong robust and low resource consumption control system for hypersonic morphing aircraft is solved, and the characteristics of faster tracking speed, higher tracking accuracy and lower resource consumption are possessed.

Description

Technical Field

[0001] The present application relates to the field of aircraft control technology, and in particular to a method and system for finite-time control of a hypersonic aircraft based on event triggering. Background Art

[0002] Hypersonic vehicles offer an effective way to access near-space. Since the successful flight of the X43-A, hypersonic vehicles have attracted worldwide attention. Traditional hypersonic vehicles are designed for specific missions, with different characteristics required for different missions or requirements.

[0003] In recent years, morphing aircraft technology has been widely researched to achieve enhanced aerodynamic properties. Consequently, research on hypersonic morphing aircraft has increased significantly. Through continuous deformation, hypersonic morphing aircraft can adapt their aerodynamic properties to the current mission requirements, thus achieving multi-mission design.

[0004] However, morphing technology not only brings a larger flight envelope, but also brings more serious challenges. Hypersonic morphing aircraft require a control system that is robust, adaptable, and resource-friendly. Summary of the Invention

[0005] Based on this, it is necessary to provide an event-triggered hypersonic aircraft finite-time control method and system with faster tracking speed, higher tracking accuracy and lower resource consumption to address the above technical problems.

[0006] A hypersonic aircraft finite-time control method based on event triggering, the method comprising:

[0007] Construct a control-oriented attitude system model for hypersonic vehicles;

[0008] Based on the posture system model, an event triggering strategy is designed, and an internal dynamic variable whose convergence characteristics match the sliding mode variable is established in the event triggering strategy;

[0009] According to the angle tracking error and reaching law, a fast finite time controller is constructed using the fast finite time control method.

[0010] Constructing an event-triggered finite-time controller according to the event-triggered strategy and the fast finite-time controller;

[0011] Acquire error information of the aircraft in real time, input the error information into the event-triggered finite time controller for calculation, and obtain attitude control input;

[0012] The attitude angle of the aircraft is adjusted and controlled through the attitude control input.

[0013] In one embodiment, the control-oriented attitude system model of the hypersonic aircraft is expressed as:

[0014]

[0015] in,

[0016]

[0017]

[0018]

[0019]

[0020] 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 ] represents the rudder deflection angle; Δ i , i=1,2 represents the aircraft modeling error and external interference; L, D, N represent lift, drag, and lateral force respectively; V, m, g represent flight speed, hypersonic aircraft mass, and gravity 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 ] Τ , 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.

[0021] In one embodiment, the event triggering strategy is expressed as:

[0022]

[0023]

[0024] Where u i(t) represents the i-th component of the control quantity u(t); i Indicates the event trigger controller that will be designed; and Indicates the start and end time of the time interval of the i-th channel under the event trigger mechanism; λ i ,i=1,2,3,δ are all coefficients;η i Represents internal dynamic variables; z u,i represents the difference between the event-triggered controller and the ideal control input; δ represents the constant coefficient used for switching trigger conditions; η i It is an internal dynamic variable.

[0025] In one embodiment, the internal dynamic variable is represented as:

[0026] When|u i When (t)|<δ, the internal dynamic variables are expressed as:

[0027]

[0028] When|u i When (t)|>δ, the internal dynamic variables are expressed as:

[0029]

[0030] Where, l1, l2, and p are coefficients; sig p (η i ) indicates that the independent variable is η i function; sign(·) is the sign function.

[0031] In one embodiment, a fast finite-time controller is constructed using a fast finite-time control method based on the angle tracking error and the reaching law, including:

[0032] Design the dynamic sliding surface, which is expressed as:

[0033]

[0034] The angular tracking error z is defined as:

[0035]

[0036] By taking the derivative of the dynamic sliding surface, we can get:

[0037]

[0038] By substituting the angular velocity state space differential equation, we can obtain:

[0039]

[0040] By combining nonlinear functions we can obtain:

[0041]

[0042] The function expressions in the formula are:

[0043]

[0044]

[0045] Therefore, a fast finite-time controller can be designed as:

[0046]

[0047] Where c 1i , i=1, 2, 3 are coefficients; F and G represent the combined nonlinear function; u represents the controller. In one embodiment, the event-triggered finite time controller is expressed as:

[0048]

[0049] Where υ0(t) represents the control input and ε is the coefficient.

[0050] In one embodiment, the error information is input into the event-triggered finite time controller for calculation to obtain a posture control input, which is expressed as:

[0051]

[0052] Where q is a positive coefficient; k j ; j=1,2,3,4 are coefficients.

[0053] A hypersonic aircraft finite time control system based on event triggering, the system comprising:

[0054] Attitude system model building module, used to build a control-oriented attitude system model for hypersonic aircraft;

[0055] An event trigger strategy design module, configured to design an event trigger strategy based on the posture system model, and to establish internal dynamic variables in the event trigger strategy whose convergence characteristics match the sliding mode variables;

[0056] A fast finite-time controller building module is used to build a fast finite-time controller using a fast finite-time control method based on the angle tracking error and the reaching law;

[0057] An event-triggered finite time controller construction module, which constructs an event-triggered finite time controller according to the event triggering strategy and the fast finite time controller;

[0058] an attitude control input calculation module, configured to obtain error information of the aircraft in real time, input the error information into the event-triggered finite time controller for calculation, and obtain attitude control input;

[0059] The attitude adjustment control module is used to adjust and control the attitude angle of the aircraft through the attitude control input.

[0060] The above-mentioned event-triggered hypersonic aircraft finite-time control method and system construct a control-oriented attitude system model of the hypersonic aircraft; design an event-triggered strategy based on the attitude system model, and establish internal dynamic variables with convergence characteristics matching the sliding mode variables in the event-triggered strategy; construct a fast finite-time controller using a fast finite-time control method based on the angle tracking error and the convergence law; construct an event-triggered finite-time controller based on the event-triggered strategy and the fast finite-time controller; obtain the error information of the aircraft in real time, input the error information into the event-triggered finite-time controller for calculation, and obtain the attitude control input; and adjust and control the attitude angle of the aircraft through the attitude control input.

[0061] The event-triggered strategy of this application uses a switching design and an internal dynamic variable design to obtain an optimal triggering strategy. Furthermore, the event-triggered finite-time controller constructed using the event-triggered strategy and a fast finite-time controller can directly obtain attitude control input based on real-time aircraft error information. This control input to the hypersonic aircraft ensures that the aircraft attitude quickly tracks the pre-set attitude angle command, ensuring rapid and stable aircraft attitude and conserving system resources by reducing the controller update frequency. This solves the difficult problem of designing a robust and low-resource control system for hypersonic deformable aircraft, and features faster tracking speed, higher tracking accuracy, and lower resource consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A schematic diagram of the steps of a hypersonic aircraft finite-time control method based on event triggering in one embodiment;

[0063] Figure 2 1 is a flow chart of event-triggered finite-time control of a hypersonic aircraft in one embodiment;

[0064] Figure 3 Schematic diagram of a tracking curve of an attitude angle versus a command in a simulation example 1 according to an embodiment;

[0065] Figure 4 Schematic diagram of a curve showing the change of angular velocity in a simulation example 1 according to an embodiment;

[0066] Figure 5 Schematic diagram of a curve showing changes in rudder deflection angle and deformation rate in a simulation example 1 according to an embodiment;

[0067] Figure 6 A schematic diagram of changes in the control variable update time and interval in a simulation example 1 in an embodiment;

[0068] Figure 7 Schematic diagram of comparison curves of attitude angle responses of simulation example 2 in one embodiment;

[0069] Figure 8 Schematic diagram of a curve showing the change of angular velocity in simulation example 2 according to an embodiment;

[0070] Figure 9 Schematic diagram of the change of the pitch rudder angle and the change of the control variable update time and update interval under different methods in simulation example 2 in one embodiment;

[0071] Figure 10 A schematic diagram of the change of the yaw rudder angle and the change of the control variable update time and update interval under different methods in a simulation example 2 in one embodiment;

[0072] Figure 11 A schematic diagram of the change in roll rudder angle and the change in control variable update time and update interval under different methods in a simulation example 2 in one embodiment;

[0073] Figure 12 1 is a structural block diagram of a hypersonic aircraft finite-time control system based on event triggering in one embodiment. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0075] It is understandable that in the process of implementing the technical solution of this application, the inventors, in order to effectively alleviate the contradiction between high-performance control and system resource constraints, solved the difficult problem of designing a robust and low-resource control system for hypersonic deformable aircraft. They designed an event-triggered finite-time control method for hypersonic aircraft. This method involves designing an event-triggered strategy that uses control variables to design events; establishing dynamic variables in the event-triggered strategy whose convergence characteristics match those of the sliding mode variables; establishing a multivariable sliding surface using angle tracking errors and derivatives of the error variables; and designing a convergence law that enables the sliding surface to converge within a finite time. By combining the state-space equations, the sliding surface, the convergence law, and the event-triggered strategy, a controller can be directly obtained without the need for complex hierarchical design. Based on a control-oriented model, a fast finite-time controller can be designed, enabling the system to converge faster than conventional finite-time control methods at the principle equilibrium point. The event-triggered mechanism uses a switching design and an internal dynamic variable design to obtain a better triggering strategy. A complete event-triggered finite-time controller for hypersonic aircraft, consisting of a fast finite-time controller and an event-triggered strategy, directly obtains attitude control inputs based on real-time aircraft error information. This control input, when fed into the hypersonic aircraft, ensures that the aircraft's attitude rapidly tracks pre-set attitude angle commands, ensuring rapid and stable aircraft attitude and conserving system resources by reducing controller update frequency. This invention utilizes fast and efficient time control technology and an event-triggered strategy to achieve rapid attitude control and stabilization for hypersonic deformable aircraft, ensuring rapid tracking of the aircraft's attitude and effectively conserving aircraft system resources. This addresses the challenge of designing a robust and resource-efficient control system for hypersonic deformable aircraft.

[0076] Among them, fast finite-time control technology enables closed-loop system errors to converge to zero within a finite time, and the system converges faster than traditional finite-time control when far from equilibrium. By establishing a multivariable sliding mode surface and combining it with fast finite-time control technology, complex hierarchical design can be avoided, and a sliding mode controller can be directly obtained. This has significant advantages in its application to hypersonic deformable aircraft.

[0077] The goal of an event-triggered strategy is to reduce the frequency of control variable updates while maintaining flight control system performance. This reduces communication pressure, extends actuator life, and ultimately conserves system resources. Modern robust controllers often rely on real-time control variable updates, with more robust controllers requiring higher control variable updates. However, hypersonic vehicles are not systems with unlimited resources; the capabilities of their onboard equipment are limited. Therefore, using an event-triggered mechanism can effectively alleviate the conflict between high-performance control and system resource constraints.

[0078] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

[0079] In one embodiment, Figure 1 and Figure 2 As shown, a hypersonic aircraft finite time control method based on event triggering is provided, comprising the following steps:

[0080] Step 102: construct a control-oriented attitude system model of a hypersonic aircraft.

[0081] It can be understood that based on the hypersonic aircraft attitude dynamics model, a control-oriented attitude system model is constructed; based on the hypersonic aircraft control-oriented attitude system model, the state space equations used for controller design are determined.

[0082] Specifically, the attitude system motion equation of the hypersonic aircraft attitude dynamics model is expressed as:

[0083]

[0084] Where α, β, γ V Represent the angle of attack, sideslip angle and roll angle respectively; ω x ,ω y ,ω z They represent roll, yaw and pitch angular velocity respectively; L, D, N represent lift, drag and lateral force respectively; V, m, g represent flight speed and gravitational acceleration respectively; M x ,M y ,M z Represent rolling, yaw and pitching moments respectively; M sx ,M sy ,M sz It represents the additional moment of triaxial deformation caused by the corresponding deformation; I x ,I y ,I z is the three-axis moment of inertia; m is the mass of the aircraft; θ is the track angle.

[0085] In one embodiment, a control-oriented attitude system model of a hypersonic aircraft is constructed, and the equation expression is:

[0086]

[0087] in,

[0088]

[0089]

[0090]

[0091]

[0092] 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 ] represents the rudder deflection angle; Δ i ,i=1,2 represents the aircraft modeling error and external interference, and the complex terms in the attitude system motion equation and the additional moments caused by deformation are combined into Δ i ; They are respectively represented by 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; q represents the dynamic pressure; S0 is the reference area; α is the vector composed of the angle of attack α=[1 α α 3 ] Τ , 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.

[0093] It can be understood that the control-oriented attitude system model established in this application is different from the general double-integral model or the strict feedback form. Instead, g1 is merged into f1. When using the three-axis angular velocity information, the complexity of the derivation is reduced, which helps to realize a simple and clear mathematical process for designing the controller and improve the tracking speed.

[0094] Step 104 : Based on the posture system model, an event triggering strategy is designed, and internal dynamic variables whose convergence characteristics match the sliding mode variables are established in the event triggering strategy.

[0095] Specifically, the event triggering strategy is expressed as:

[0096]

[0097]

[0098] Where u i (t) represents the i-th component of the control quantity u(t); i Indicates the event trigger controller that will be designed; and Indicates the start and end time of the time interval of the i-th channel under the event trigger mechanism; λ i,i=1,2,3,δ are all coefficients;η i Represents internal dynamic variables; z u,i represents the difference between the event-triggered controller and the ideal control input; δ represents the constant coefficient used for switching trigger conditions. The strategy uses a switching design. According to |u i |<δ satisfies the situation and switches to different designs, which will participate in |u i |<δThe trigger threshold adjustment.

[0099] Among them, λ i >0,c i >0(i=1,2,3); δ>0; m>1; 1>n>0; z u =υ(t)-u(t), specifically z u =[z u,1 ,z u,2 ,z u,3 ] Τ .

[0100] More specifically, the internal dynamic variables are represented as:

[0101] When|u i When (t)|<δ, the internal dynamic variables are expressed as:

[0102]

[0103] When|u i When (t)|>δ, the internal dynamic variables are expressed as:

[0104]

[0105] Where, l1, l2, and p are coefficients; sig p (η i ) indicates that the independent variable is η i Function, the operation method is sig p (η i )=|η i | p sign(η i );sign(·) is the sign function. η i The trigger threshold will be adjusted based on the change rate designed as above.

[0106] After analysis, it can be found that the internal dynamic variable is bounded and η>0. The detailed analysis process is as follows:

[0107] When researching |u i When (t)|<δi, we can get

[0108]

[0109] Establish auxiliary variable η′, and we can get

[0110]

[0111] Assume that the auxiliary variable η′ reaches η′<0 for the first time, at this time t=t′. Considering sig p (η′) has the same sign as η′. By studying the changing trend of η′(t0), we can see that its derivative will reach the first time on the interval t∈[0,t′) This means that η′ will not continue to decrease because it is already very close to 0. Moreover, this will lead to Further explanation This contradicts the above assumption. Therefore, we can get η i >η′≥0.

[0112] Since η>0, we can obtain the following inequality.

[0113]

[0114] therefore, Heng is established.

[0115] Taking all cases into consideration, η>0 holds for all u(t).

[0116] For any control variable u(t) satisfying |u(t)|≥δ, the following expression always holds true.

[0117]

[0118] Therefore, we can get:

[0119]

[0120] This shows that η is a bounded quantity.

[0121] Step 106 : constructing a fast finite-time controller using a fast finite-time control method according to the angle tracking error and the reaching law.

[0122] It can be understood that the multivariable sliding surface is established using the angle tracking error and the derivative function of the error variable; and the sliding surface is made to converge within a finite time by designing the reaching law.

[0123] Specifically, the dynamic sliding surface is designed and expressed as:

[0124]

[0125] The angular tracking error z is defined as:

[0126]

[0127] By taking the derivative of the dynamic sliding surface, we can get the sliding surface derivative function, which is:

[0128]

[0129] By substituting the angular velocity state space differential equation, we can obtain:

[0130]

[0131] By combining nonlinear functions we can obtain:

[0132]

[0133] The function expressions in the formula are:

[0134]

[0135]

[0136] Therefore, a fast finite-time controller can be designed as:

[0137]

[0138] Where c 1i , i=1,2,3 are coefficients; F and G represent the combined nonlinear functions; u represents the controller (rudder angle).

[0139] It is worth noting that, thanks to the designed dynamic sliding surface, the traditional internal and external layered design is avoided, and the ideal aircraft control input can be directly obtained from the sliding surface; the designed convergence law can make the sliding surface converge in a finite time; after the sliding surface converges to the origin, the error will also converge in a finite time; the closed-loop system will converge faster than the traditional finite-time convergence when far away from the equilibrium point.

[0140] Step 108: construct an event-triggered finite-time controller according to the event-triggered strategy and the fast finite-time controller.

[0141] Specifically, the ideal control input is:

[0142]

[0143] Where:

[0144] According to |u i |If satisfied, we can get u i (t) satisfies the general relationship shown below

[0145]

[0146] Where: If |u i|≥δ r i =0; if |u i |<δ, then r i = 1. Define the diagonal matrix R = diag(r1r2 r3).

[0147] More specifically, other parameters are defined, where:

[0148] The parameters used to indicate whether a dynamic event is triggered are:

[0149]

[0150] The corresponding matrix form is:

[0151] b=diag(b1 b2 b3);

[0152] The vector form of the event trigger controller is:

[0153] υ=[υ1,υ2,υ3] Τ ;

[0154] The vector form of dynamic internal variables is:

[0155] η=[η1,η2,η3] Τ ;

[0156] A variable used to express the relationship between the ideal control input and the event-triggered controller is:

[0157]

[0158] Another variable used to express the relationship between the ideal control input and the event-triggered controller is:

[0159]

[0160] Substituting the expression of the sliding surface derivative function into the equation, we can get:

[0161]

[0162] Then the event-triggered finite time controller is designed as:

[0163]

[0164] Where:

[0165] Step 110 , obtaining error information of the aircraft in real time, inputting the error information into an event to trigger a finite time controller to perform calculations, and obtaining attitude control input.

[0166] Specifically, the attitude control input is:

[0167]

[0168] Where q is a positive coefficient and satisfies q∈(0 1); k j ; j=1,2,3,4 are coefficients.

[0169] Step 112: Adjust and control the attitude angle of the aircraft through attitude control input.

[0170] The above-mentioned event-triggered hypersonic aircraft finite-time control method and system construct a control-oriented attitude system model of the hypersonic aircraft; design an event-triggered strategy based on the attitude system model, and establish internal dynamic variables with convergence characteristics matching the sliding mode variables in the event-triggered strategy; construct a fast finite-time controller using a fast finite-time control method based on the angle tracking error and the convergence law; construct an event-triggered finite-time controller based on the event-triggered strategy and the fast finite-time controller; obtain the error information of the aircraft in real time, input the error information into the event-triggered finite-time controller for calculation, and obtain the attitude control input; and adjust and control the attitude angle of the aircraft through the attitude control input.

[0171] This invention designs an event-triggered finite-time controller for a hypersonic aircraft attitude model using fast finite-time control and event-triggered techniques. This method, employing fast finite-time control and sliding mode control techniques, can directly determine the controller without complex hierarchical design, ensuring that the aircraft's angle tracking error converges within a finite time, and even exceeding the convergence rate of conventional finite-time control when the error is large. The event-triggered mechanism can reduce the frequency of control variable updates while ensuring control performance, thus conserving aircraft system resources. This method is suitable for hypersonic aircraft attitude control and has significant engineering application significance. It effectively addresses the challenges of high-performance, low-consumption attitude control for hypersonic aircraft, achieving faster tracking speed, higher tracking accuracy, and lower resource consumption.

[0172] Compared with traditional event-triggered strategies, this application has the following advantages:

[0173] (1) Use switching design in event triggering strategy design to combine the advantages of both events;

[0174] (2) Using dynamic internal variable design, this variable will participate in the adjustment of the trigger threshold to obtain better triggering results;

[0175] (3) The convergence characteristics of the internal dynamic variables match the sliding mode variables, and the event trigger threshold can be adjusted accurately and quickly to save aircraft resources.

[0176] 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. In addition, 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.

[0177] In one embodiment, two simulations are provided to verify and illustrate the effectiveness and superiority of the present invention. Simulation Example 1 verifies the effectiveness of the designed event-triggered finite-time control method; Simulation Example 2 demonstrates the superiority of this method by comparing it with other methods. The following describes the embodiments in which this method is applied in detail.

[0178] For all simulation cases, the controller parameters are selected as follows:

[0179] The coefficient settings for the sliding surface are shown in Table 1

[0180] Table 1 Sliding surface coefficients and values

[0181]

[0182] The coefficient settings for the controller are shown in Table 2

[0183] Table 2 Controller coefficients and values

[0184]

[0185] The coefficient settings for event triggering strategy are shown in Table 3

[0186] Table 3 Event trigger strategy coefficients and values

[0187]

[0188] The initial value settings for hypersonic flight are shown in Table 4

[0189] Table 4 Hypersonic flight values

[0190]

[0191] (1) Simulation example settings

[0192] The purpose of this example is to verify the effectiveness of the controller. Therefore, a time-varying angle command is used as input into the controller's calculation equation to obtain the control input. Simultaneously, the aircraft attitude model is controlled according to the set initial values ​​and the flight altitude and speed to obtain a real-time state response. The curves comparing the state response and the angle command are observed to verify the effectiveness of the method designed by this invention and the rationality of this embodiment.

[0193] In this example, the aircraft angle command is set as:

[0194]

[0195] β c =0°,0<t<10

[0196]

[0197] In order to make the instructions smoother, the following second-order servo system is used to generate instructions:

[0198]

[0199] The second simulation example verifies the advantages of the proposed event-triggered finite-time control method in tracking performance and resource consumption. Comparative experiments were conducted using the more commonly used fixed threshold event triggering, relative threshold event triggering, and switching event triggering. Tracking accuracy and the frequency of aircraft control variable updates were also evaluated to verify the advantages of the proposed method in terms of high tracking performance and low resource consumption.

[0200] In this embodiment, the aircraft angle command is set as:

[0201] α c =5°

[0202] β c =0°

[0203] γ Vc =10°

[0204] The second-order servo system used to generate instructions is the same as that in Simulation Example 1.

[0205] (2) Analysis of simulation results

[0206] 2. Results Analysis

[0207] The simulation results of simulation examples 1 and 2 are as follows Figure 3-Figure 11 As shown in Table 5-6.

[0208] The simulation results of Example 1 are as follows Figures 3 to 6The simulation curves demonstrate the effectiveness of the designed controller. It can be clearly observed that during the aircraft's deformation flight phase, the application of the designed event-triggered finite-time control system effectively ensures closed-loop system stability, without a significant increase in control error. Figure 3 The good tracking accuracy of the three-channel attitude angles under the action of the designed controller is demonstrated, and all attitude angles can reach the ideal angle within 2; Figure 4 The three-channel attitude angular velocity change curve is shown; Figure 5 The event-triggered finite-time control input curves and the continuous two-step deformation are shown. The deformation settings are kept consistent in the simulations of this study. Figure 6 The designed event triggering mechanism demonstrates the timing of event triggering and the time interval between two event triggering events. According to the event triggering rules, the control input is updated as the event triggers. This indicates that the frequency of controller updates is significantly reduced, effectively relieving the pressure on data transmission within the flight control system and extending the life of the servo system to a certain extent.

[0209] By analyzing the relationship between event triggering timing and control performance, we found that when the aircraft's attitude needs to be adjusted rapidly, event triggering is more frequent, the time interval between event triggering is shorter, and the controller requires more adjustments. However, as the aircraft's attitude gradually stabilizes under the control of the controller, the frequency of event triggering decreases, the time interval between triggering increases, and the number of controller adjustments decreases. This indicates that when the attitude changes rapidly, frequent event triggering is necessary to enable the controller to quickly adjust to track rapidly changing angle commands. Once the attitude stabilizes, the controller only needs periodic adjustments to maintain control accuracy.

[0210] The simulation results of the second simulation example are as follows: Figures 7 to 11 As shown in Table 5-6, Command represents the attitude angle tracking command, that is, the command for the angle of attack, sideslip angle, and roll angle; Angles represents the actual attitude angle response; times(s) represents the flight simulation time in seconds; and deg represents the angle in degrees.

[0211] According to the figure, Figure 8As shown in Table 5, the simulation examples designed by the present invention verify that the method designed by the present invention (SDETM) can still maintain high control performance when applied to aircraft. Compared with traditional event triggering methods such as fixed threshold event triggering (FTETM), relative threshold event triggering (RTETM) and switching event triggering (SETM), it has the most ideal balance between performance and resource consumption. By comparing the flight control accuracy and triggering times under continuous time conditions, it can be found that after using the designed event triggering mechanism, the control accuracy is only slightly reduced. Taking the angle of attack as an example, it is reduced by 0.016°, but the number of controller adjustments is only 27.5% of that under continuous time. This shows that there is no significant performance loss in control performance, but the aircraft system resource consumption is effectively reduced. The statistics in the table are the tracking errors at the final moment. Observing Tables 5-6, it is found that the relative threshold triggering has a significant performance loss in the entire tracking process. At the same time, combining the continuous time condition and the four trigger mechanisms, it is shown that the interval between two time triggers will indeed affect the accuracy of angle tracking and the rapidity of tracking error convergence. However, by reasonably designing the trigger mechanism and adjusting the event triggering conditions, time and interval between the two triggers, the impact on control performance can be effectively controlled, and the advantages of the event triggering mechanism can be fully utilized.

[0212] To better achieve attitude control tasks during hypersonic flight, this invention, based on the fast finite-time control method, designs an event-triggered fast finite-time control method that achieves ideal tracking performance. Based on the fast finite-time control method and sliding mode control, an ideal controller is designed. This event-triggered strategy reduces aircraft resource consumption while maintaining controller robustness. This invention will contribute to the development of control technologies for hypersonic aircraft with high tracking performance and low resource consumption.

[0213] In one embodiment, Figure 12 As shown, a hypersonic aircraft finite-time control system based on event triggering is provided, comprising: an attitude system model construction module 202, an event triggering strategy design module 204, a fast finite-time controller construction module 206, an event triggering finite-time controller construction module 208, an attitude control input calculation module 210, and an attitude adjustment control module 212, wherein:

[0214] The attitude system model building module 202 is used to build a control-oriented attitude system model for a hypersonic aircraft.

[0215] The event trigger strategy design module 204 is used to design an event trigger strategy based on the posture system model, and to establish internal dynamic variables in the event trigger strategy whose convergence characteristics match the sliding mode variables.

[0216] The fast finite time controller construction module 206 is used to construct a fast finite time controller using a fast finite time control method according to the angle tracking error and the reaching law.

[0217] The event-triggered finite time controller construction module 208 constructs an event-triggered finite time controller according to the event-triggered strategy and the fast finite time controller.

[0218] The attitude control input calculation module 210 is used to obtain the error information of the aircraft in real time, and trigger the finite time controller to perform calculations based on the error information input event to obtain the attitude control input.

[0219] The attitude adjustment control module 212 is used to adjust and control the attitude angle of the aircraft through attitude control input.

[0220] The specific definitions of the event-triggered hypersonic aircraft finite-time control system can be found in the definitions of the event-triggered hypersonic aircraft finite-time control method described above and will not be repeated here. Each module in the event-triggered hypersonic aircraft finite-time control system described above can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0221] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. 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. By way of illustration and not limitation, RAM is available in various 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).

[0222] The technical features of the above embodiments can 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.

[0223] The above-described embodiments merely represent several embodiments of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements are all within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A finite-time control method for a hypersonic vehicle based on event triggering, characterized in that: The method comprises: Construct a control-oriented attitude system model for hypersonic vehicles; Based on the posture system model, an event triggering strategy is designed, and an internal dynamic variable whose convergence characteristics match the sliding mode variable is established in the event triggering strategy; According to the angle tracking error and reaching law, a fast finite time controller is constructed using the fast finite time control method. Constructing an event-triggered finite-time controller according to the event-triggered strategy and the fast finite-time controller; Acquire error information of the aircraft in real time, input the error information into the event-triggered finite time controller for calculation, and obtain attitude control input; Adjusting and controlling the attitude angle of the aircraft through the attitude control input; The event triggering strategy is expressed as: ； ； Where, Indicates the control amount No. Quantity Indicates the event trigger controller that will be designed; and Indicates the first The start and end time of the time interval of each channel; 、 All are coefficients; Represents internal dynamic variables; represents the difference between the event-triggered controller and the ideal control input; Indicates the constant coefficient used for switching trigger conditions; The internal dynamic variables are represented as: when When , the internal dynamic variables are expressed as: ； when When , the internal dynamic variables are expressed as: ； Where, 、 、 All are coefficients; Indicates that the independent variable is function; is a symbolic function; The event-triggered finite time controller is expressed as: ； Where, represents the control input; is the coefficient; The error information is input into the event-triggered finite time controller for calculation to obtain the attitude control input, which is expressed as: ； Where, is a positive coefficient; is the coefficient.

2. The event-triggered hypersonic vehicle finite-time control method according to claim 1, characterized in that: The control-oriented attitude system model of the hypersonic aircraft is expressed as: ； in, ； ； ； ； Where, Indicates attitude angle; Indicates attitude angular velocity; Indicates the rudder deflection angle; Represents aircraft modeling errors and external disturbances; They represent lift, drag, and lateral force respectively; They represent flight speed, hypersonic vehicle mass, and gravitational acceleration respectively; represents the moment of inertia of the three axes; represents the track angle; Indicates dynamic pressure; , , They are respectively expressed as the pitching 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; is the reference area; is the vector consisting of the angle of attack , ; For The relevant pitching moment coefficient term; is the yaw moment coefficient term related to the sideslip angle; is the rolling moment coefficient term related to the roll angle.

3. The event-triggered hypersonic vehicle finite-time control method according to claim 1, characterized in that: According to the angle tracking error and reaching law, a fast finite time control method is used to construct a fast finite time controller, including: Design the dynamic sliding surface, which is expressed as: ； Angular tracking error Defined as: ； By taking the derivative of the dynamic sliding surface, we can get: ； By substituting the angular velocity state space differential equation, we can obtain: ； By combining nonlinear functions we can obtain: ； The function expressions in the formula are: ； ； Therefore, a fast finite-time controller can be designed as: ； Where, is the coefficient; and represents the nonlinear function after merging; Represents a controller.

4. A hypersonic aircraft finite time control system based on event triggering, characterized in that: The method for finite-time control of a hypersonic aircraft based on event triggering according to any one of claims 1 to 3 is adopted, wherein the system comprises: Attitude system model building module, used to build a control-oriented attitude system model for hypersonic aircraft; An event trigger strategy design module, configured to design an event trigger strategy based on the posture system model, and to establish internal dynamic variables in the event trigger strategy whose convergence characteristics match the sliding mode variables; A fast finite-time controller building module is used to build a fast finite-time controller using a fast finite-time control method based on the angle tracking error and the reaching law; An event-triggered finite time controller construction module, which constructs an event-triggered finite time controller according to the event triggering strategy and the fast finite time controller; an attitude control input calculation module, configured to obtain error information of the aircraft in real time, input the error information into the event-triggered finite time controller for calculation, and obtain attitude control input; The attitude adjustment control module is used to adjust and control the attitude angle of the aircraft through the attitude control input.

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