Aircraft tilting motion control method with convergence in preset time

Abstract

The invention belongs to the technical field of aircraft control. The invention provides an aircraft tilting motion control method with convergence in preset time. According to the embodiment of the invention, the preset time scale function is combined with sliding mode control, so that convergence time setting does not depend on initial conditions, parameter setting is easy, the inclination angle and the inclination angle speed can be converged within the preset convergence time, good preset time convergence performance and robustness are achieved, and it can be ensured that an aircraft inclination motion system is rapid and stable. The method can be easily applied to aircraft tilting motion stability control under different conditions.

Description

Technical Field

[0001] The disclosed embodiments relate to the field of aircraft control technology, and in particular to a method for controlling aircraft tilt motion with predetermined time convergence. Background Art

[0002] Tilt motion stability is crucial to flight stability and maneuverability. By adjusting the tilt angle, the attitude of the aircraft can be precisely controlled, allowing it to maintain a stable attitude when performing various flight missions. For axisymmetric aircraft using rectangular coordinate control methods, tilt motion stability is crucial: on the one hand, changes in tilt angular velocity will cause cross-coupling between pitch, yaw, and tilt channels, resulting in reduced control efficiency and even uncontrollable high-speed roll; on the other hand, tilt motion may cause inconsistent coordinate systems during the guidance process, thereby causing pitch and yaw channel guidance signal disorder, reducing guidance accuracy and affecting flight missions.

[0003] In summary, fast, stable and robust tilt motion control is an important guarantee for the stable flight of aircraft. However, in order to achieve fast tilt motion stability control, traditional control methods need to repeatedly adjust the control parameters to obtain the desired effect.

[0004] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0005] It should be noted that this section is intended to provide background or context for the technical solutions of the present disclosure stated in the claims. The description herein is not admitted to be prior art by virtue of being included in this section. Summary of the invention

[0006] The purpose of the embodiments of the present disclosure is to provide a method for controlling the tilt motion of an aircraft with a predetermined time convergence, thereby overcoming one or more problems caused by the limitations and defects of the related art at least to a certain extent.

[0007] According to an embodiment of the present disclosure, a method for controlling a tilt motion of an aircraft with a predetermined time convergence is provided, the method comprising: According to the aircraft kinematic equation, a small disturbance linearization model of aircraft tilt motion is established; Establishing an aircraft tilt motion system model based on the small disturbance linearization model of the aircraft tilt motion; Constructing a first predetermined time scale function of a sliding mode convergence segment and a second predetermined time scale function of an error convergence segment; Designing a predetermined time sliding mode controller according to the aircraft tilt motion system model, the first predetermined time scale function and the second predetermined time scale function; The predetermined time sliding mode controller is used to control the tilting motion of the aircraft.

[0008] Furthermore, according to the aircraft kinematic equation, the step of establishing a small disturbance linearization model of the aircraft tilt motion includes: The aircraft kinematic equations are decoupled to obtain a small disturbance linearization model of the aircraft tilt motion.

[0009] Furthermore, the expression of the small disturbance linearization model of the aircraft tilt motion is:

[0010] in, is the tilt angle, for The differential of is the tilt angular velocity, for The differential of is the rudder deflection angle, is the aerodynamic damping coefficient of the aircraft, is the aileron efficiency of the aircraft.

[0011] Furthermore, the expression of the aircraft tilt motion system model is:

[0012] Among them, the first state quantity , is the desired tilt angle, for The differential of the second state quantity , for The differential of .

[0013] Further, the expression of the first predetermined time scale function is:

[0014] in, is the time taken for the sliding mode convergence segment to converge, To control the startup time, is the expected sliding mode convergence time, is the time gain; The expression of the second predetermined time scale function is:

[0015] in, is the expected error convergence time, It is the time taken for the error convergence segment to converge.

[0016] Furthermore, the step of designing a predetermined time sliding mode controller according to the aircraft tilt motion system model, the first predetermined time scale function and the second predetermined time scale function includes: designing a predetermined time sliding surface according to the second predetermined time scale function; According to the first predetermined time scale function, designing a predetermined time sliding mode reaching law; The predetermined time sliding mode controller is designed according to the aircraft tilt motion system model, the predetermined time sliding mode surface and the predetermined time sliding mode reaching law.

[0017] Furthermore, the expression of the predetermined time sliding surface is:

[0018] in, is the first control parameter, is the second control parameter, and , , , for The differential of The expression of the predetermined time sliding mode reaching law is:

[0019] in, is the third control parameter, is the fourth control parameter, is the fifth control parameter, is the fifth control parameter, , , , , , for The differential of The expression of the predetermined time sliding mode controller is:

[0020] in, .

[0021] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects: In the embodiment of the present disclosure, through the above-mentioned predetermined time convergence aircraft tilt motion control method, on the one hand, the predetermined time scale function is combined with the sliding mode control, so that the convergence time setting does not depend on the initial conditions and is easy to set parameters, the tilt angle and the tilt angular velocity can converge within the predetermined convergence time, and have good predetermined time convergence performance and robustness, and can ensure that the aircraft tilt motion system is fast and stable. On the other hand, the method is easy to apply to the aircraft tilt motion stability control under different conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0023] Figure 1 A step diagram showing a method for controlling the tilt motion of an aircraft with a predetermined time convergence in an exemplary embodiment of the present disclosure; Figure 2 A structural diagram of aircraft tilt motion stabilization control based on a predetermined time sliding mode controller in an exemplary embodiment of the present disclosure is shown; Figure 3 shows a curve of tilt angle variation in an exemplary embodiment of the present disclosure; Figure 4 shows a curve of tilt angular velocity variation in an exemplary embodiment of the present disclosure; Figure 5 The figure shows the rudder angle variation curve in an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0025] In addition, the accompanying drawings are only schematic illustrations of the embodiments of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated descriptions will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0026] This example embodiment provides a method for controlling the tilt motion of an aircraft with a predetermined time convergence. Figure 1 As shown in , the aircraft tilt motion control method with predetermined time convergence may include: steps S101 to S105.

[0027] Step S101: establishing a small disturbance linearization model of aircraft tilt motion according to the aircraft kinematic equation; Step S102: establishing an aircraft tilt motion system model according to the aircraft tilt motion small disturbance linearization model; Step S103: constructing a first predetermined time scale function of the sliding mode convergence segment and a second predetermined time scale function of the error convergence segment; Step S104: designing a predetermined time sliding mode controller according to the aircraft tilt motion system model, the first predetermined time scale function and the second predetermined time scale function; Step S105: using the predetermined time sliding mode controller to control the tilting motion of the aircraft.

[0028] Through the above-mentioned aircraft tilt motion control method with predetermined time convergence, on the one hand, the predetermined time scale function is combined with the sliding mode control, so that the convergence time setting does not depend on the initial conditions and is easy to set parameters, the tilt angle and the tilt angular velocity can converge within the predetermined convergence time, and have good predetermined time convergence performance and robustness, which can ensure that the aircraft tilt motion system is fast and stable. On the other hand, the method is easy to apply to the aircraft tilt motion stability control under different conditions.

[0029] Next, we will refer to Figures 1 to 5 Each step of the above-mentioned method for controlling the tilt motion of an aircraft with predetermined time convergence in this exemplary embodiment is described in more detail.

[0030] In step S101, a small disturbance linearization model of aircraft tilt motion is established according to the aircraft kinematic equation.

[0031] Specifically, the kinematic equations of the axisymmetric aircraft are decoupled to obtain the small perturbation linearization model of the aircraft's tilt motion: (1) in, is the tilt angle, is the tilt angular velocity, is the rudder deflection angle, the dynamic coefficient is the aerodynamic damping coefficient of the aircraft, is the aileron efficiency of the aircraft.

[0032] In step S102, an aircraft tilt motion system model is established according to the aircraft tilt motion small disturbance linearization model.

[0033] Specifically, the aircraft tilt motion system model is further established based on the small disturbance linearization model of the aircraft tilt motion, and the expected tilt angle is , record the state quantity , , control amount , then the aircraft tilt motion system model is as follows: (2) In step S103, a first predetermined time scale function of the sliding mode convergence segment and a second predetermined time scale function of the error convergence segment are constructed.

[0034] Construct two predetermined time scale functions and design the predetermined time gain , must meet .

[0035] Specifically, the first stage is the sliding mode convergence stage. To control the startup time, is the expected sliding mode convergence time, Design a predetermined time scale function for the convergence time of the sliding mode convergence segment: (3) The second stage is the error convergence stage. is the expected error convergence time, Design a predetermined time scale function for the convergence time of the error convergence segment: (4) make , , for a continuously differentiable function If satisfied (5) in , first stage , , second stage , .

[0036] For any

[0037] (6) Then we have: (7) therefore, (8) Right now: (9) The scheduled time adjustment for the current phase can be guaranteed.

[0038] In step S104, a predetermined time sliding mode controller is designed according to the aircraft tilt motion system model, the first predetermined time scale function and the second predetermined time scale function.

[0039] Specifically, design a time-scheduled sliding mode controller and set the control parameters , , , , , , analyze the predetermined time stability of the controller.

[0040] First, establish the predetermined time sliding surface: (10) Secondly, design the sliding mode reaching law with a predetermined time: (11) The scheduled time sliding mode controller is expressed as follows: (12) Analyze the predetermined time stability of the predetermined time sliding mode controller and construct the function of the sliding mode convergence segment: (13) Taking the derivative, we get: (14) That is, the system can be set at the scheduled time. It converges to the sliding surface at all times, and at this time it satisfies Right now: (15) Construct a function for the error convergence segment: (16) Taking the derivative, we get: (17) That is, the system error can be calculated according to the predetermined time. The tilt angle of the aircraft converges to 0 at all times, and the tilt motion of the aircraft is stable.

[0041] In step S105, the predetermined time sliding mode controller is used to control the tilting motion of the aircraft.

[0042] Specifically, a sliding mode controller with a predetermined time is designed to be introduced into the aircraft tilt motion system, and a rudder angle instruction is generated according to the tilt angle and tilt angle velocity measured and fed back by the inertial component. The actuator is actuated according to the instruction to change the aircraft attitude and achieve stable control.

[0043] In a specific embodiment, the axisymmetric aircraft kinematic equations are decoupled to obtain a small perturbation linearized model of the aircraft tilt motion: (1) The current tilt angle for , tilt angular velocity for , rudder deflection angle for , the aerodynamic damping coefficient of the aircraft in the tilt direction , the aileron efficiency of the aircraft .

[0044] According to the small disturbance linearization model of aircraft tilt motion, an aircraft tilt motion system model is established.

[0045] Specifically, the aircraft tilt motion system model is further established based on the small disturbance linearization model of the aircraft tilt motion, and the expected tilt angle is , record the state quantity , , control amount , then the aircraft tilt motion system model is as follows: (2) To ensure the stability of the system, the desired tilt angle for .

[0046] Construct two predetermined time scale functions and design the predetermined time gain =4.

[0047] The first stage is the sliding mode convergence stage. To control the startup time, is the expected sliding mode convergence time, The convergence time of the sliding mode convergence segment is 1.5s, 1.0s and 0.5s respectively, and the predetermined time scale function is designed: (3) The second stage is the error convergence stage. is the expected error convergence time, The convergence time of the error convergence segment is 0.5s, 1.0s and 0.5s respectively, and the predetermined time scale function is designed: (4) make , , for a continuously differentiable function If satisfied: (5) in , first stage , , second stage , .

[0048] For any

[0049] (6) Then we have: (7) therefore, (8) Right now: (9) The scheduled time adjustment for the current phase can be guaranteed.

[0050] Design a time-scheduled sliding mode controller and set control parameters , , , , , , analyze the predetermined time stability of the controller.

[0051] First, establish the predetermined time sliding surface: (10) Secondly, design the sliding mode reaching law with a predetermined time: (11) The scheduled time sliding mode controller is expressed as follows: (12) Analyze the predetermined time stability of the predetermined time sliding mode controller and construct the function of the sliding mode convergence segment: (13) Taking the derivative, we get: (14) That is, the system can be set at the scheduled time. It converges to the sliding surface at all times, and at this time it satisfies Right now: (15) Construct a function for the error convergence segment: (16) Taking the derivative, we get: (17) That is, the system error can be calculated according to the predetermined time. The tilt angle of the aircraft converges to 0 at all times, and the tilt motion of the aircraft is stable.

[0052] like Figure 2 The figure shows the structure diagram of the aircraft tilt motion stability control based on the scheduled time sliding mode controller. The designed scheduled time sliding mode controller is introduced into the aircraft tilt motion system, and the rudder deflection angle command is generated according to the tilt angle and tilt angle velocity measured and fed back by the inertial component. The actuator changes the aircraft attitude according to the command action to achieve stable control.

[0053] In a specific embodiment, algorithm simulation is carried out to verify the effectiveness of the present application.

[0054] Figures 3 to 5 The black dashed line indicates , The black straight line represents the simulation result of , The black dotted line indicates the simulation result of , The simulation results are shown in Figure 2.

[0055] Figure 3 The simulation results show that under the control method of the aircraft tilt motion with a predetermined time convergence in the present application, the predetermined time and All can be preset, and the tilt angle can converge according to the desired predetermined time. , and , Both simulations were performed in When convergence, , Simulation can be Converges when Converges quickly to , thereby achieving stable control of the aircraft's tilting motion.

[0056] Figure 4 is the tilt angular velocity variation curve. The simulation results show that under the predetermined time convergence aircraft tilt motion control method of the present application, the predetermined time and All can be preset, and the tilt angular velocity can converge according to the desired predetermined time. , and , Both simulations were performed in When convergence, , Simulation can be The whole tilt angular velocity is less than , that is, this method ensures the rapid convergence of the tilt angular velocity, thereby achieving stable control of the tilt motion of the aircraft.

[0057] Figure 5 The simulation results show that under the aircraft tilt motion control method with a predetermined time convergence in the present application, the tilt rudder angle is Within this range, the tilt angle can be effectively controlled to achieve stable control of the tilting motion of the aircraft.

[0058] Through the above-mentioned aircraft tilt motion control method with predetermined time convergence, on the one hand, the predetermined time scale function is combined with the sliding mode control, so that the convergence time setting does not depend on the initial conditions and is easy to set parameters, the tilt angle and the tilt angular velocity can converge within the predetermined convergence time, and have good predetermined time convergence performance and robustness, which can ensure that the aircraft tilt motion system is fast and stable. On the other hand, the method is easy to apply to the aircraft tilt motion stability control under different conditions.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0061] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A method for controlling the tilt motion of an aircraft with a predetermined time convergence, characterized in that: The method includes: According to the aircraft kinematic equation, a small disturbance linearization model of aircraft tilt motion is established; Establishing an aircraft tilt motion system model based on the small disturbance linearization model of the aircraft tilt motion; Constructing a first predetermined time scale function of a sliding mode convergence segment and a second predetermined time scale function of an error convergence segment; Designing a predetermined time sliding mode controller according to the aircraft tilt motion system model, the first predetermined time scale function and the second predetermined time scale function; The predetermined time sliding mode controller is used to control the tilting motion of the aircraft.

2. The method for controlling the tilt motion of an aircraft with a predetermined time convergence according to claim 1, characterized in that: According to the aircraft kinematic equation, the steps of establishing the small disturbance linearization model of aircraft tilt motion include: The aircraft kinematic equations are decoupled to obtain a small disturbance linearization model of the aircraft tilt motion.

3. The method for controlling the tilt motion of an aircraft with a predetermined time convergence according to claim 2, characterized in that: The expression of the small disturbance linearization model of the aircraft tilt motion is: in, is the tilt angle, for The differential of is the tilt angular velocity, for The differential of is the rudder deflection angle, is the aerodynamic damping coefficient of the aircraft, is the aileron efficiency of the aircraft.

4. The method for controlling the tilt motion of an aircraft with a predetermined time convergence according to claim 3, characterized in that: The expression of the aircraft tilt motion system model is: Among them, the first state quantity , is the desired tilt angle, for The differential of the second state quantity , for The differential of .

5. The method for controlling the tilt motion of an aircraft with a predetermined time convergence according to claim 4, characterized in that: The expression of the first predetermined time scale function is: in, is the time taken for the sliding mode convergence segment to converge, To control the startup time, is the expected sliding mode convergence time, is the time gain; The expression of the second predetermined time scale function is: in, is the expected error convergence time, It is the time taken for the error convergence segment to converge.

6. The method for controlling the tilt motion of an aircraft with a predetermined time convergence according to claim 5, characterized in that: The step of designing a predetermined time sliding mode controller according to the aircraft tilt motion system model, the first predetermined time scale function and the second predetermined time scale function comprises: designing a predetermined time sliding surface according to the second predetermined time scale function; According to the first predetermined time scale function, designing a predetermined time sliding mode reaching law; The predetermined time sliding mode controller is designed according to the aircraft tilt motion system model, the predetermined time sliding mode surface and the predetermined time sliding mode reaching law.

7. The method for controlling the tilt motion of an aircraft with a predetermined time convergence according to claim 6, characterized in that: The expression of the predetermined time sliding surface is: in, is the first control parameter, is the second control parameter, and , , , for The differential of The expression of the predetermined time sliding mode reaching law is: in, is the third control parameter, is the fourth control parameter, is the fifth control parameter, is the fifth control parameter, , , , , , for The differential of The expression of the predetermined time sliding mode controller is: in, .

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