Method and Medium for Cooperative Control of Deviation Correction and Braking of Aircraft Antiskid Braking System

Abstract

The present invention provides a collaborative control method for deviation correction and braking of an aircraft anti-skid braking system, including: establishing an asymmetric aircraft anti-skid braking system model; setting a deviation correction and braking composite sliding mode surface for the asymmetric aircraft anti-skid braking system; using an adaptive RBF neural network to estimate the uncertain disturbances of the system; setting a sliding mode control law and introducing the disturbance estimation value as compensation into the sliding mode control law to achieve efficient braking and anti-skid deviation correction control of the aircraft anti-skid braking system under asymmetric conditions. In view of the problems existing in the traditional aircraft anti-skid braking system model, the present invention establishes an overall model of the asymmetric aircraft anti-skid braking system, uses an adaptive RBF neural network to realize the estimation of crosswind disturbances during the taxiing process, and through a braking deviation correction sliding mode control strategy, realizes efficient braking and anti-skid deviation correction control of the aircraft anti-skid braking system under asymmetric conditions, reduces the risk of the aircraft running off the runway, and improves the reliability and safety of the anti-skid braking system.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft anti-skid brake control, and in particular to a deviation correction and braking coordinated control method and medium for an aircraft anti-skid brake system based on a balanced compensation sliding mode strategy. Background Art

[0002] The landing roll phase of an aircraft is a high-incidence stage for aircraft accidents. According to relevant domestic and international statistics, 49.1% of various aircraft safety accidents occur during the landing roll phase. With the rapid development of aviation technology, modern aircraft are gradually moving towards high reliability, high speed, and lightweight design, which also places higher demands on the safety and stability of aircraft anti-skid braking systems.

[0003] Most common aircraft anti-skid braking system control designs are based on a single-wheel model, assuming the system is in a load-balanced state and ignoring the coupling between lateral and longitudinal torques such as friction, lateral force, and uncertain interference forces. These overly simplistic and idealized system models fail to accurately reflect the aircraft's ground taxiing process. This results in low reliability and safety, inefficient control, and poor robustness. Therefore, it is necessary to conduct research on aircraft anti-skid braking systems under asymmetric motion, strong coupling, and multiple constraints, in order to establish an aircraft anti-skid braking system model that better reflects the actual braking process.

[0004] Furthermore, during ground taxiing, system asymmetry can cause the aircraft to yaw, potentially leading to accidents. Existing control methods typically employ cross-protection to correct the aircraft's yaw. When the angular velocity difference between the two main wheels exceeds a threshold, the brakes on the lower-speed wheels are fully released, increasing their angular velocity. While this control method is simple, excessive pressure release reduces braking efficiency.

[0005] In view of the above problems, it is necessary to improve the braking efficiency of the aircraft anti-skid braking system from the aspects of asymmetric aircraft anti-skid braking model, anti-skid braking control law and uncertain interference estimation. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies in the above-mentioned background technology and to provide a coordinated control scheme for the correction and braking of an aircraft anti-skid braking system based on a balanced compensation sliding mode strategy, so as to solve the problem of efficient braking and anti-skid correction of an aircraft during asymmetric ground taxiing.

[0007] To achieve the above-mentioned object, the present invention provides a method for coordinated control of deviation correction and braking of an aircraft anti-skid brake system, comprising the following steps:

[0008] S1, considering the uncertain interference of the system and the coupling between the lateral and longitudinal moments, conducts a multi-faceted force analysis of the aircraft during ground taxiing and establishes an asymmetric aircraft anti-skid braking system model;

[0009] S2, set the correction and braking composite sliding mode surface of the asymmetric aircraft antiskid braking system;

[0010] S3, use an adaptive RBF neural network to estimate the uncertain interference of the system;

[0011] S4, set the sliding mode control law, and introduce the interference estimation value as compensation into the sliding mode control law to achieve efficient braking and antiskid correction control of the aircraft antiskid braking system under asymmetric conditions.

[0012] Furthermore, the asymmetric aircraft antiskid braking system model established in S1 is:

[0013]

[0014] where, V x , V y are the longitudinal speed and lateral speed of the aircraft respectively, λ l , λ r are the slip ratios of the left main wheel and right main wheel of the aircraft respectively, e is the angular velocity difference between the left and right main wheels of the aircraft, m is the mass of the aircraft, T0 is the engine thrust, F x , F y are the resultant forces on the front wheel in the x-axis and y-axis directions respectively, F xl , F yl are the resultant forces on the left main wheel in the x-axis and y-axis directions respectively, F xr , F yr are the resultant forces on the right main wheel in the x-axis and y-axis directions respectively, F Z is the uncertain crosswind interference of the system, F D is the headwind resistance, N 1l , N 1r are the supporting forces of the left and right main wheels, μ l , μ r are the bonding coefficients of the left main wheel and right main wheel respectively, P l , P r are the braking torques of the left main wheel and right main wheel respectively, r is the wheel radius, ρ is the air density, δ is the tail rudder angle, I c is the wheel moment of inertia, Ω is the yaw angular velocity.

[0015] Furthermore, establish the asymmetric aircraft airframe dynamics model in S1:

[0016]

[0017]

[0018] where, V x , V yare the longitudinal speed and lateral speed of the aircraft respectively, m is the mass of the aircraft, T0 is the engine thrust, F x is the resultant force on the front wheel of the aircraft in the x-axis direction, F xl , F xr are the resultant forces on the left main wheel and right main wheel in the x-axis direction respectively, F D is the headwind resistance, F δ is the rudder force, δ is the tail rudder angle, ρ δ is the aircraft yaw coefficient, F y is the resultant force on the front wheel of the aircraft in the y-axis direction, F yl , F yr are the resultant forces on the left main wheel and right main wheel in the y-axis direction respectively, F z is the uncertain crosswind interference force, G is the gravity, F L is the air lift force, N2 is the front wheel support force, N 1l , N 1r is the bilateral main wheel support force, Ω is the yaw angular velocity, a and b are the projection distances from the front wheel and the left and right main wheels to the aircraft center of gravity respectively, c is the projection distance between the left and right main wheels, h is the height from the aircraft center of gravity to the ground;

[0019] Establish an asymmetric aircraft wheel dynamics model:

[0020]

[0021] where r is the effective radius of the wheel, μ l , μ r are the bonding coefficients of the left main wheel and right main wheel respectively, P l , P r are the braking torques of the left main wheel and right main wheel respectively, ω l , ω r are the angular velocities of the left main wheel and right main wheel respectively, I c is the moment of inertia of the left main wheel and right main wheel;

[0022] Establish a tire-runway bonding coefficient model:

[0023] Under the action of the braking torque, the linear velocity of the wheel is always less than the longitudinal velocity of the aircraft. The slip ratio is defined as the ratio of the wheel sliding relative to the runway. The slip ratios λ l , λ r are expressed as:

[0024]

[0025] The bonding coefficient μ between the tire and the runway is used to reflect the magnitude of the bonding force between the wheel and the runway during the braking process of the aircraft. The magic formula is used as the relationship model between the bonding coefficient and the slip ratio:

[0026]

[0027] Among them, D is the peak factor, C is the stiffness factor, and B is the shape factor;

[0028] Therefore, it is obtained that:

[0029]

[0030] Define the angular velocity difference between the left and right main wheels:

[0031] e = ω l - ω r

[0032] Derive the formula for the angular velocity difference between the left and right main wheels and substitute the formula of the non-symmetric aircraft wheel dynamics model to obtain:

[0033]

[0034] Thus, the non-symmetric aircraft anti-skid braking system model is obtained.

[0035] Furthermore, the specific deviation correction and braking composite sliding surface in S2 are:

[0036]

[0037] Among them, s f is the deviation correction sliding surface, s l , s r are the braking sliding surfaces of the left and right main wheels respectively, x 1d represents the lateral velocity of the ideal braking, that is, the deviation-free braking process, x 2d , x 3d represent the optimal slip rates of the left runway and the right runway respectively, and g(x4) is the balance compensation function, expressed as:

[0038]

[0039] Furthermore, when x4 ≥ 0 in S2, the braking sliding surfaces of the left and right main wheels are simplified to:

[0040]

[0041] At this time, the angular velocity of the left main wheel is greater than or equal to that of the right main wheel. The control target of the left main wheel is to track the speed of the right main wheel, and the control target of the right main wheel is to track the optimal slip rate;

[0042] When x4 < 0, the braking sliding surfaces of the left and right main wheels are simplified to:

[0043]

[0044] At this time, the angular velocity of the left main wheel is less than that of the right main wheel. The control target of the left main wheel is to track the optimal slip rate, and the control target of the right main wheel is to track the speed of the left main wheel.

[0045] Furthermore, the adaptive RBF neural network parameter update rate in S3 is expressed as: Wherein γ is the adaptive gain value, and γ>0.

[0046] Furthermore, the exponential reaching law is introduced in S4:

[0047]

[0048] in, is the differential of the composite sliding surface, sgn() is the sign function, ε f ,k f ,ε l ,k l ,ε r ,k r is the exponential reaching law parameter;

[0049] Calculate the rudder angle:

[0050]

[0051] Calculate the left main wheel braking torque:

[0052]

[0053] Calculate the right main wheel braking torque:

[0054]

[0055] in,

[0056] F=[1-g(x4)]f2(x)-[(x2-x 2d +x4)τ(x4)-g(x4)]f4(x),

[0057]

[0058] H=-ε l sgn(s l )-k l s l ,

[0059]

[0060] M=-ε r sgn(s r )-k r s r,

[0061] where τ(x4) is an impulse function.

[0062] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the method for coordinated control of deviation correction and braking of the aircraft anti-skid braking system as described above.

[0063] The above solution of the present invention has the following beneficial effects:

[0064] The solution for coordinated control of deviation correction and braking of the aircraft anti-skid braking system provided by the present invention, aiming at the problems existing in the traditional aircraft anti-skid braking system model, establishes an overall model of the asymmetric aircraft anti-skid braking system, uses an adaptive RBF neural network to estimate the crosswind interference during the taxiing process, and through the braking deviation correction sliding mode control strategy, realizes the efficient braking and anti-skid deviation correction control of the aircraft anti-skid braking system under asymmetric conditions, effectively reduces the risk of the aircraft running off the runway, and improves the reliability and safety of the anti-skid braking system.

[0065] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation part. Description of the Drawings

[0066] Figure 1 is a flowchart of steps

[0067] Figure 2 is a top view of the aircraft;

[0068] Figure 3 is a side view of the aircraft;

[0069] Figure 4 is a schematic diagram of the force on the left main wheel;

[0070] Figure 5 is a comparison chart of the estimated curve and the actual curve of the crosswind interference;

[0071] Figure 6 is the lateral speed of the aircraft during braking;

[0072] Figure 7 is the supporting force of the bilateral main wheels of the aircraft during braking;

[0073] Figure 8 is the speed curve of the aircraft and the bilateral main wheel speed curve during braking;

[0074] Figure 9 is the angular velocity difference curve of the bilateral main wheels of the aircraft during braking;

[0075] Figure 10 is the slip ratio curve of the bilateral main wheels during braking. Specific Embodiments

[0076] The following specific examples illustrate the implementation manners of the present disclosure. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The present disclosure can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0077] It should be noted that the following describes various aspects of embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, this device and / or this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0078] It should also be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present disclosure. The diagrams only show the components related to the present disclosure, rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex. In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0079] As Figure 1 shown, an embodiment of the present invention provides a method for coordinated control of deviation correction and braking of an aircraft anti-skid braking system, including:

[0080] S1, considering the uncertain crosswind interference of the system and the coupling relationship between the longitudinal and lateral moments, perform a three-dimensional six-degree-of-freedom force analysis on the aircraft's ground roll process, as Figure 2 、 Figure 3 shown, and establish an asymmetric aircraft anti-skid braking system model.

[0081] Before establishing the asymmetric airframe dynamics model, the following assumptions need to be made: ① The aircraft airframe and landing gear are regarded as ideal rigid bodies, and the elastic deformation of the aircraft in the vertical direction is not considered; ② When the aircraft lands, the engine is in the slow thrust state, and the gyroscopic moment generated by its rotor is not considered; ③ The aircraft uncertainty interference acts on the aircraft center of gravity and is perpendicular to the airframe; ④ During the aircraft taxiing phase, the pitch angle and roll angle changes are small and can be ignored.

[0082] According to Newton's second law and the rigid body rotation law, an asymmetric aircraft airframe dynamics model is established:

[0083]

[0084] Among them, V x , V y are the longitudinal speed and lateral speed of the aircraft respectively, m is the mass of the aircraft, T0 is the engine thrust, F x is the resultant force received by the front wheel of the aircraft in the x-axis direction, F xl , F xr are the resultant forces received by the left main wheel and the right main wheel in the x-axis direction respectively, F D is the headwind resistance, F δ is the rudder force, δ is the tail rudder angle, ρ δ is the aircraft yaw coefficient, F y is the resultant force received by the front wheel of the aircraft in the y-axis direction, F yl , F yr are the resultant forces received by the left main wheel and the right main wheel in the y-axis direction respectively, F z is the uncertain crosswind interference force, G is the gravity, F L is the air lift force, N2 is the front wheel support force, N 1l , N 1r are the bilateral main wheel support forces, Ω is the yaw angular velocity, a and b are the projection distances from the front wheel and the left and right main wheels to the aircraft center of gravity respectively, c is the projection distance between the left and right main wheels, and h is the height from the aircraft center of gravity to the ground.

[0085] An asymmetric aircraft wheel dynamics model is established:

[0086] During the aircraft taxiing process, the wheels are mainly affected by the braking torque and the engagement torque. The force on the left main wheel is as shown in Figure 4 and an aircraft wheel dynamics model is established:

[0087]

[0088] Among them, r is the effective radius of the wheel, μ l , μ r are the engagement coefficients of the left main wheel and the right main wheel respectively, P l , P rThe braking torques of the left main wheel and the right main wheel respectively, ω l , ω r The angular velocities of the left main wheel and the right main wheel respectively, I c are the moments of inertia of the left main wheel and the right main wheel.

[0089] Establish a tire - runway adhesion coefficient model:

[0090] Under the action of the braking torque, the wheel linear velocity is always less than the longitudinal velocity of the aircraft. Define the slip ratio as the ratio of the wheel sliding relative to the runway. The slip ratios λ of the left main wheel and the right main wheel l , λ r are expressed as:

[0091]

[0092] The adhesion coefficient μ between the tire and the runway is an important parameter in braking control, which is used to reflect the magnitude of the binding force between the wheel and the runway during the braking process of the aircraft. In this example, the Magic Formula is selected as the relationship model between the adhesion coefficient and the slip ratio:

[0093]

[0094] where D is the peak factor, C is the stiffness factor, and B is the shape factor.

[0095] By comparing the experimental data and referring to relevant literature, the peak factor, stiffness factor, shape factor, and the optimal slip ratio λ under the three runway conditions of dry, wet, and ice are obtained d as shown in Table 1:

[0096] Table 1: Values of each factor and optimal slip ratio under different runway conditions

[0097]

[0098] The runway simulation environment of the double - sided main wheels in this example is shown in Table 2:

[0099] Table 2: Runway simulation environment of double - sided main wheels

[0100]

[0101] Derive formula (4) and substitute formulas (1), (2), and (3) to get:

[0102]

[0103] Define the angular velocity difference between the left and right main wheels:

[0104] e = ω l - ω r (7)

[0105] Derive formula (7) and substitute formula (3) to obtain:

[0106]

[0107] Simultaneously solve formulas (1), (3), and (8) to obtain the asymmetric aircraft antiskid braking system model:

[0108]

[0109] where λ l , λ r are the slip ratios of the left and right main wheels of the aircraft respectively, e is the angular velocity difference between the left and right main wheels of the aircraft, μ l , μ r are the adhesion coefficients of the left and right main wheels respectively, P l , P r are the braking torques of the left and right main wheels respectively, r is the wheel radius, ρ is the air density, and I c is the moment of inertia of the wheel.

[0110] Taking V y , λ l , λ r , and e as the system state variables, and δ, P l , P r as the system control variables. Let x1 be V y , x2 be λ l , x3 be λ r , x4 be e, u1 be δ, u2 be P l , and u3 be P r , then the asymmetric aircraft antiskid braking system model can be expressed in the following form:

[0111]

[0112] where x = [x1 x2 x3 x4] T , u = [u1 u2 u3] T , f(x) = [f1(x) f2(x) f3(x) f4(x)] T ,

[0113] B = [B1 B2 B3 B4] T ,

[0114] S2, set the braking deviation correction composite sliding surface of the asymmetric aircraft antiskid braking system.

[0115] The specific braking deviation correction composite sliding surface is:

[0116]

[0117] Among them, s f is the deviation correction sliding mode surface, s l , s r are the braking sliding mode surfaces of the left main wheel and the right main wheel respectively, x 1d represents the lateral speed of ideal braking, that is, without deviation correction braking process, x 1d = 0, x 2d , x 3d represent the optimal slip ratios of the left runway and the right runway respectively, which can be obtained from Table 1, and g(x4) is the balance compensation function, expressed as:

[0118]

[0119] When ω l ≥ ω r , that is, when x4≥0, the braking sliding mode surfaces of the left and right main wheels can be simplified as:

[0120]

[0121] At this time, the angular velocity of the left main wheel is greater than or equal to that of the right main wheel. The control target of the left main wheel is to track the speed of the right main wheel, and the control target of the right main wheel is to track the optimal slip ratio.

[0122] When ω l <ω r , that is, when x4<0, the braking sliding mode surfaces of the left main wheel and the right main wheel can be simplified as:

[0123]

[0124] At this time, the angular velocity of the left main wheel is less than that of the right main wheel. The control target of the left main wheel is to track the optimal slip ratio, and the control target of the right main wheel is to track the speed of the left main wheel.

[0125] In summary, the braking deviation correction composite sliding mode surface set in this step can theoretically ensure that the aircraft does not yaw during the ground roll process, and the braking efficiency of the aircraft is the highest when the angular velocities of the left and right main wheels are consistent.

[0126] S3. Use an adaptive RBF neural network to estimate the uncertain crosswind interference of the system.

[0127] In this example, considering the uncertain crosswind interference in the system, the calculation formula of the crosswind interference force is defined as:

[0128]

[0129] Among them, ρ is the air density, S is the wing area, C w is the crosswind coefficient, V windis the crosswind speed.

[0130] Refer to relevant literature and set the crosswind speed as follows:

[0131]

[0132] Among them, V m is the maximum crosswind speed, t m represents the start time of the crosswind. The specific parameters are shown in Table 3.

[0133] Table 3: Crosswind interference parameter values

[0134]

[0135] For the asymmetric aircraft anti-skid braking system, the uncertain interference term is analyzed separately:

[0136]

[0137] Set up an RBF neural network with a 2-5-1 structure and take the network input The output of the j-th neuron in the network hidden layer The network output is the estimated value of the uncertainty interference Among them, b j , c j are the center and width of the Gaussian function, and are the weights of the network.

[0138] The network parameter update rate can be expressed as: Among them, γ is the adaptive gain value and γ > 0.

[0139] S4. Set up the sliding mode control law and introduce the estimated value of the crosswind interference as compensation into the control law.

[0140] Introduce the exponential reaching law:

[0141]

[0142] Among them, is the differential of the composite sliding mode surface, sgn() is the sign function, ε f , k f , ε l , k l , ε r , k r are the exponential reaching law parameters. Take ε = 1.1, k = 40, ε l = 1.1, k l = 5, ε r = 1.1, k r = 10.

[0143] Calculate the rudder angle:

[0144]

[0145] Calculate the braking torque of the left main wheel:

[0146]

[0147] Calculate the braking torque of the right main wheel:

[0148]

[0149] Wherein,

[0150] F = [1 - g(x4)]f2(x) - [(x2 - x 2d + x4)τ(x4) - g(x4)]f4(x),

[0151]

[0152] H = -ε l sgn(s l ) - k l s l ,

[0153]

[0154] M = -ε r sgn(s r ) - k r s r ,

[0155] Where τ(x4) is the impulse function.

[0156] From Figure 5 It can be seen that the RBF neural network in this embodiment can estimate the uncertain crosswind interference existing in the system in a short time, and its estimation error is within a reasonable range. From Figure 6 It can be seen that the deviation correction control can preferably control the lateral speed of the aircraft to zero, and the aircraft does not yaw. From Figure 7 It can be seen that at the moments of 6s and 10s, due to the change of the runway environment, the supporting forces of the bilateral main wheels jump, but overall, the supporting forces of the bilateral main wheels are basically the same, and the aircraft is in a load-balanced state, and the deviation correction control effect is good. From Figure 8 and Figure 9 It can be seen that the speed of the aircraft and the bilateral main wheels decelerate smoothly, and the speeds of the bilateral main wheels are basically the same. From Figure 10 It can be seen that after the runway environment changes at the moments of 6s and 10s, the controller can quickly track the optimal slip ratio, significantly improving the braking efficiency of the system.

[0157] Based on the same inventive concept, this embodiment also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the aforementioned aircraft anti-skid braking system deviation correction and braking collaborative control method.

[0158] The computer-readable medium includes, but is not limited to, any type of disk (including floppy disks, hard disks, optical disks, CD-ROMs, and magneto-optical disks), ROM, RAM, EPROM (Erasable Programmable Read-Only Memory), EEPROM, flash memory, magnetic cards, or optical cards. That is to say, the readable medium includes any medium that stores or transmits information in a form readable by a device (such as a computer).

[0159] The beneficial effects of the computer-readable storage medium are similar to those of the aforementioned method, and will not be elaborated here.

[0160] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for collaborative control of deviation correction and braking of an aircraft anti-skid braking system, characterized in that, It includes the following steps: S1. Considering the uncertain disturbances of the system and the coupling between the longitudinal and lateral moments, conduct a multi-faceted force analysis on the aircraft ground taxiing process, and establish an anti-skid braking system model for an asymmetric aircraft; S2. Set the correction and braking composite sliding mode surface of the anti-skid braking system for an asymmetric aircraft; S3. Use an adaptive RBF neural network to estimate the uncertain disturbances of the system; S4. Set the sliding mode control law, and introduce the disturbance estimation value as a compensation into the sliding mode control law to achieve efficient braking and anti-skid correction control of the aircraft anti-skid braking system under asymmetric conditions; The anti-skid braking system model for an asymmetric aircraft established in S1 is: Among them, V x , V y are respectively the longitudinal speed and the lateral speed of the aircraft, λ l , λ r are respectively the slip ratios of the left main wheel and the right main wheel of the aircraft, e is the angular velocity difference between the left and right main wheels of the aircraft, m is the mass of the aircraft, T0 is the engine thrust, F x , F y are respectively the resultant forces received by the front wheel in the x-axis and y-axis directions, F xl , F yl are respectively the resultant forces received by the left main wheel in the x-axis and y-axis directions, F xr , F yr are respectively the resultant forces received by the right main wheel in the x-axis and y-axis directions, F Z is the uncertain crosswind interference of the system, F D is the headwind resistance, N 1l , N 1r are the supporting forces of the left and right main wheels, μ l , μ r are respectively the bonding coefficients of the left main wheel and the right main wheel, P l , P r are respectively the braking torques of the left main wheel and the right main wheel, r is the wheel radius, ρ is the air density, δ is the rudder angle, I c is the moment of inertia of the wheel, and Ω is the yaw angular velocity.

2. The deviation correction and braking cooperative control method for an aircraft anti-skid braking system according to claim 1, wherein Establish the dynamic model of the asymmetric aircraft fuselage in S1: Among them, V x , V y are the longitudinal speed and lateral speed of the aircraft respectively, m is the mass of the aircraft, T0 is the engine thrust, F x is the resultant force received by the front wheel of the aircraft in the x-axis direction, F xl , F xr are the resultant forces received by the left main wheel and the right main wheel in the x-axis direction respectively, F D is the headwind resistance, F δ is the rudder force, δ is the tail rudder angle, ρ δ is the yaw coefficient of the aircraft, F y is the resultant force received by the front wheel of the aircraft in the y-axis direction, F yl , F yr are the resultant forces received by the left main wheel and the right main wheel in the y-axis direction respectively, F z is the uncertain crosswind interference force, G is the gravity, F L is the air lift force, N2 is the front wheel support force, N 1l , N 1r are the bilateral main wheel support forces, Ω is the yaw angular velocity, a and b are the projection distances from the front wheel and the left and right main wheels to the aircraft's center of gravity respectively, c is the projection distance between the left and right main wheels, and h is the height from the aircraft's center of gravity to the ground; Establish the dynamic model of the asymmetric aircraft wheels: where r is the effective radius of the wheel, μ l , μ r are the combination coefficients of the left main wheel and the right main wheel respectively, P l , P r are the braking torques of the left main wheel and the right main wheel respectively, ω l , ω r are the angular velocities of the left main wheel and the right main wheel respectively, I c is the moment of inertia of the left main wheel and the right main wheel; Establish the tire-runway adhesion coefficient model: Under the action of the braking torque, the wheel linear velocity is always less than the longitudinal velocity of the aircraft. The slip ratio is defined as the ratio of the wheel sliding relative to the runway. The slip ratios of the left main wheel and the right main wheel are λ l , λ r which are expressed as: The adhesion coefficient μ between the tire and the runway is used to reflect the magnitude of the adhesion force between the aircraft wheels and the runway during braking. Use the magic formula as the relationship model between the adhesion coefficient and the slip ratio: Where, D is the peak factor, C is the stiffness factor, and B is the shape factor; Therefore, it is obtained: Define the angular velocity difference between the left and right main wheels: e = ω l -ω r Derive the formula for the angular velocity difference between the left and right main wheels and substitute the formula of the dynamic model of the asymmetric aircraft wheels to obtain: Thus, the anti-skid braking system model for an asymmetric aircraft is obtained.

3. The deviation correction and braking cooperative control method for an aircraft anti-skid braking system according to claim 2, characterized in that The specific correction and braking composite sliding mode surface in S2 is: Among them, s f is the deviation correction sliding surface, s l , s r are the braking sliding surfaces of the left main wheel and the right main wheel respectively, x 1d represents the lateral speed of the ideal brake, i.e., the non-deviation correction braking process, x 2d , x 3d represent the optimal slip ratios of the left runway and the right runway respectively, and g(x4) is the balance compensation function, which is expressed as:

4. The aircraft anti-skid braking system deviation correction and braking collaborative control method according to claim 3, characterized in that, In S2, when x4≥0, the braking sliding mode surface of the left and right main wheels is simplified to: At this time, the angular velocity of the left main wheel is greater than or equal to that of the right main wheel. The control target of the left main wheel is to track the speed of the right main wheel, and the control target of the right main wheel is to track the optimal slip ratio; When x4<0, the braking sliding mode surfaces of the left and right main wheels are simplified to: At this time, the angular velocity of the left main wheel is less than that of the right main wheel. The control target of the left main wheel is to track the optimal slip ratio, and the control target of the right main wheel is to track the speed of the left main wheel.

5. The method for collaborative control of deviation correction and braking of an aircraft anti-skid braking system according to claim 4, characterized in that, The parameter update rate of the adaptive RBF neural network in S3 is expressed as: where γ is the adaptive gain value and γ >

0.

6. The method for collaborative control of deviation correction and braking of an aircraft anti-skid braking system according to claim 5, characterized in that, Introduce the exponential reaching law in S4: Among them, is the differential of the composite sliding surface, sgn() is the sign function, ε f , k f , ε l , k l , ε r , k r are the exponential reaching law parameters; Calculate the rudder angle: Calculate the braking torque of the left main wheel: Calculate the braking torque of the right main wheel: Where, F = [1 - g(x4)]f2(x) - [(x2 - x 2d + x4)τ(x4) - g(x4)]f4(x), H = -ε l sgn(s l ) - k l s l , M = -ε r sgn(s r ) - k r s r , Where τ(x4) is the impact function.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it realizes the anti-skid braking system correction and braking collaborative control method described in any one of claims 1-6.

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