Aircraft emergency landing course acceleration analysis method and device

Abstract

The invention provides an aircraft emergency landing course acceleration analysis method and device, and belongs to the technical field of aircraft design, and the method comprises the steps: constructing a course acceleration analysis model under an aircraft emergency landing working condition; acquiring numerical values of parameters required by the course acceleration analysis model in an airplane emergency landing course acceleration analysis process; based on the numerical values of the required parameters and a course acceleration analysis model, a course acceleration time history under the airplane emergency landing working condition is obtained through calculation, and based on the course acceleration time history, an acceleration design reference value of the forward course of the airborne equipment is determined. The method is clear in thought and sufficient in theoretical basis, can reasonably and effectively determine the course acceleration of the aircraft body and the airborne equipment during emergency landing of the aircraft, and has important guiding significance for design of the aircraft structure and the airborne equipment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aircraft design, and particularly relates to an aircraft emergency landing heading acceleration analysis method and device. BACKGROUND

[0002] When an aircraft is in emergency landing, the brake system, the reverse thrust system or the deceleration system may fail, causing the aircraft to rush out of the runway and hit the arresting net or the arresting system of special materials, etc. obstacles, so that the aircraft stops suddenly, and a large heading forward acceleration is generated due to the inertial effect. How to more accurately calculate the heading forward acceleration is of great significance to the crashworthiness design of the aircraft and the on-board equipment.

[0003] Currently, the national military standard and the airworthiness standard both put forward relevant provisions for the acceleration, for example, the national military standard GJB 67.3A-2008 stipulates in section 3.4 "crash load" that all fixed, movable equipment and auxiliary equipment and their components, and the mechanism that may injure personnel or hinder personnel from safely escaping from the aircraft in case of crash, should be designed according to the load coefficient determined by analysis and special research, or designed according to the following limit load coefficient: 9 forward and 1.5 backward. The national military standard GJB 150.15A-2009 stipulates in section 7.2.3 "procedure III-crash safety test" that the centrifuge reaches the speed at which the test piece can generate the acceleration value of 4.3 and Table 3, and according to the type of aircraft and the installation position of on-board equipment, the stipulated longitudinal acceleration value is different, which is 3g-40g forward and 3g-20g backward. CCAR 25-R4 stipulates in "emergency landing conditions article 25.561 general" that the design of the structure must be able to give every occupant a reasonable chance of surviving a hard impact landing and under the following conditions, in which the occupant is subjected to a limit inertial load factor of 9.0 forward and 1.5 backward relative to the surrounding structure. It can be seen that the heading acceleration values required by different standards are different, which is not conducive to the crashworthiness design of the aircraft and the on-board equipment.

[0004] In addition, in the prior art, the heading acceleration of the aircraft and the on-board equipment during emergency landing is calculated by multi-body or structural impact dynamics simulation analysis method, that is, a simulation analysis model of the aircraft body and the on-board equipment is usually established by using commercial software in engineering, and a dynamic simulation of the process of the aircraft hitting the obstacle is carried out, so as to extract the acceleration response of the aircraft body and the on-board equipment. However, the model quality requirement of this method is very high, the simulation analysis period is also long, and the result precision is also limited. SUMMARY

[0005] The purpose of the present application is to provide an aircraft emergency landing heading acceleration analysis method and device to solve or alleviate at least one problem in the background art.

[0006] In a first aspect, the technical solution of the present application is: an aircraft emergency landing heading acceleration analysis method, comprising:

[0007] constructing a heading acceleration analysis model under an aircraft emergency landing working condition;

[0008] obtaining numerical values of parameters required by the heading acceleration analysis model in the aircraft emergency landing heading acceleration analysis process;

[0009] calculating a heading acceleration time history under the aircraft emergency landing working condition based on the numerical values of the required parameters and the heading acceleration analysis model, and determining a heading forward acceleration design reference value of an onboard device based on the heading acceleration time history.

[0010] In at least one embodiment of the present application, the process of constructing a heading acceleration analysis model under an aircraft emergency landing working condition comprises:

[0011] establishing a dynamic equation of the whole aircraft, wherein the dynamic equation of the whole aircraft comprises a kinetic energy equation and a potential energy equation of the whole aircraft;

[0012] obtaining a dynamic response equation of the whole aircraft based on Lagrange equation,

[0013] constructing a whole aircraft collision force calculation model based on Hertz contact theory, obtaining a collision force by solving the whole aircraft collision force calculation model, and obtaining a horizontal acceleration response time history of the onboard device by solving the dynamic response equation of the whole aircraft based on the collision force.

[0014] In at least one embodiment of the present application, the kinetic energy equation is: ;

[0015] In the formula, T is the kinetic energy of the whole aircraft;

[0016] m1 is the total mass of the aircraft body excluding the onboard device;

[0017] m2 is the mass of the onboard device;

[0018] is the horizontal velocity of the aircraft body;

[0019] is the horizontal velocity of the onboard device.

[0020] In at least one embodiment of the present application, the potential energy equation is:

[0021] In the formula, U is the potential energy of the whole aircraft;

[0022] k1 and k2 are respectively the connection stiffness between the aircraft body and the onboard device;

[0023] x1(t) is the horizontal displacement of the aircraft body;

[0024] x2(t) is the horizontal displacement of the airborne equipment.

[0025] In at least one embodiment of the present application, the dynamic response equation of the aircraft as a whole is:

[0026] (4)

[0027] In the formula: is the horizontal force when the aircraft body collides with the obstacle, is the horizontal acceleration response of the aircraft body; is the horizontal acceleration response of the airborne equipment.

[0028] In at least one embodiment of the present application, the aircraft as a whole collision force calculation model is:

[0029]

[0030] In the formula: K is the contact stiffness between the aircraft body and the obstacle; a is the collision index; and l is the damping coefficient.

[0031] In at least one embodiment of the present application, the damping coefficient

[0032] In the formula: c r is the recovery coefficient of the material, and V is the initial horizontal velocity of the aircraft body colliding with the obstacle.

[0033] In at least one embodiment of the present application, the process of solving the aircraft as a whole collision force calculation model to obtain the collision force is:

[0034] The aircraft body and the airborne equipment are regarded as a whole, and the aircraft as a whole collision force calculation model is arranged according to Newton's second law to obtain the arranged collision motion equation;

[0035] The arranged collision motion equation is solved based on the numerical integration method to obtain the time history of the horizontal displacement x1(t) of the aircraft body and the horizontal velocity v1(t) of the aircraft body The time history of the horizontal displacement x1(t) of the aircraft body and the horizontal velocity v1(t) of the aircraft body are brought into the aircraft as a whole collision force calculation model to obtain the collision force.

[0036] In at least one embodiment of the present application, the arranged collision motion equation is: .

[0037] In at least one embodiment of the present application, the numerical integration method comprises a fourth-order Runge-Kutta method, and the time histories of the body displacement and the body velocity are obtained by determining the initial conditions, the time step and the calculation duration.

[0038] In at least one embodiment of the present application, the peak value of the horizontal acceleration response time history of the airborne equipment is extracted as the acceleration design reference value of the airborne equipment in the forward direction of the flight path.

[0039] In the second aspect, the technical solution provided by the present application is an aircraft emergency landing flight path acceleration analysis device, comprising:

[0040] A model component module is configured to construct a flight path acceleration analysis model under an emergency landing condition of an aircraft.

[0041] A parameter acquisition module is configured to acquire a value of a parameter required by the flight path acceleration analysis model in a flight path acceleration analysis process of an aircraft.

[0042] A parameter calculation module is configured to calculate a time history of the flight path acceleration under the emergency landing condition of the aircraft based on the value of the required parameter and the flight path acceleration analysis model, and determine an acceleration design reference value of the airborne equipment in the forward direction of the flight path based on the time history of the flight path acceleration.

[0043] In at least one embodiment of the present application, the process of constructing the flight path acceleration analysis model under the emergency landing condition of the aircraft by the model component module comprises:

[0044] A dynamic equation of the whole aircraft is established, and the dynamic equation of the whole aircraft comprises a kinetic energy equation and a potential energy equation of the whole aircraft.

[0045] A dynamic response equation of the whole aircraft is obtained based on the Lagrange equation,

[0046] A collision force calculation model of the whole aircraft is constructed based on the Hertz contact theory, a collision force is obtained by solving the collision force calculation model of the whole aircraft, and a horizontal acceleration response time history of the airborne equipment is obtained by solving the dynamic response equation of the whole aircraft based on the collision force.

[0047] In at least one embodiment of the present application, the kinetic energy equation is: ;

[0048] In the formula, T is the kinetic energy of the whole aircraft.

[0049] m1 is the total mass of the aircraft body excluding the airborne equipment.

[0050] m2 is the mass of the airborne equipment.

[0051] is the horizontal velocity of the body.

[0052] is the horizontal velocity of the airborne equipment.

[0053] In at least one embodiment of the present application, the potential energy equation is:

[0054] wherein U is the potential energy of the whole aircraft;

[0055] k1 and k2 are the connection stiffness between the aircraft body and the airborne equipment, respectively;

[0056] x1(t) is the horizontal displacement of the aircraft body;

[0057] x2(t) is the horizontal displacement of the airborne equipment.

[0058] In at least one embodiment of the present application, the dynamic response equation of the whole aircraft is:

[0059] (4)

[0060] wherein: is the horizontal force when the aircraft body collides with the obstacle, is the horizontal acceleration response of the aircraft body; is the horizontal acceleration response of the airborne equipment.

[0061] In at least one embodiment of the present application, the whole aircraft collision force calculation model is:

[0062]

[0063] wherein K is the contact stiffness between the aircraft body and the obstacle; a is the collision index; and l is the damping coefficient.

[0064] In at least one embodiment of the present application, the damping coefficient

[0065] wherein c r is the recovery coefficient of the material, and V is the initial horizontal velocity of the aircraft body colliding with the obstacle.

[0066] In at least one embodiment of the present application, the process of solving the whole aircraft collision force calculation model to obtain the collision force is:

[0067] The aircraft body and the airborne equipment are regarded as a whole, and the whole aircraft collision force calculation model is arranged according to Newton's second law to obtain the arranged collision motion equation;

[0068] The arranged collision motion equation is solved based on the numerical integration method to obtain the horizontal displacement of the aircraft body and the horizontal velocity time history of the body horizontal displacement and the time history of the body horizontal velocity into an aircraft overall crash force calculation model to obtain the crash force.

[0069] In at least one embodiment of the present application, the rearranged crash motion equation is: .

[0070] In at least one embodiment of the present application, the numerical integration method includes a fourth-order Runge-Kutta method, and the time history of the body displacement and the time history of the body velocity are obtained by determining initial conditions, a time step and a calculation duration.

[0071] In at least one embodiment of the present application, the peak value of the horizontal acceleration response time mileage of the airborne equipment is extracted, and the peak value is the acceleration design reference value of the forward direction of the airborne equipment.

[0072] In a third aspect, the technical solution provided by the present application is an electronic device, comprising:

[0073] one or more processors;

[0074] a memory;

[0075] one or more application programs stored in the memory and configured to be executed by the one or more processors, the one or more application programs being configured to implement the aircraft emergency landing heading acceleration analysis method according to any one of the above.

[0076] In a fourth aspect, the technical solution provided by the present application is a computer readable storage medium, which stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by a processor to implement the aircraft emergency landing heading acceleration analysis method according to any one of the above.

[0077] The method of the present application has clear ideas, sufficient theoretical basis, and can reasonably and effectively determine the heading acceleration of the aircraft and the airborne equipment during emergency landing of the aircraft, which has important guiding significance for the design of aircraft structure and airborne equipment. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the technical solutions provided by the present application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the present application.

[0079] Figure 1 is a schematic diagram of the aircraft emergency landing heading acceleration analysis method of the present application.

[0080] Figure 2 A yaw acceleration analysis model schematic diagram with the connection stiffness located in front of the airborne equipment for an embodiment of the present application.

[0081] Figure 3 A yaw acceleration analysis model schematic diagram with the connection stiffness located in front of the airborne equipment for an embodiment of the present application.

[0082] Figure 4 A yaw acceleration analysis model schematic diagram with the connection stiffness located in front of the airborne equipment for an embodiment of the present application.

[0083] Figure 5 A body horizontal displacement time history schematic diagram for an embodiment of the present application.

[0084] Figure 6 A body horizontal velocity time history schematic diagram for an embodiment of the present application.

[0085] Figure 7 A body collision force time history schematic diagram for an embodiment of the present application.

[0086] Figure 8 An acceleration response time history schematic diagram of the airborne equipment for an embodiment of the present application.

[0087] Figure 9 An airplane emergency landing yaw acceleration analysis device schematic diagram for the present application. DETAILED DESCRIPTION

[0088] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described in more detail below with the aid of the accompanying drawings of the embodiments of the present application.

[0089] The present application provides an airplane emergency landing yaw acceleration analysis method, which is based on a plurality of parameters of an airplane and airborne equipment, and solves the dynamic response acceleration of the system according to the Hertz contact theory and the dynamic response equation, so as to improve the analysis accuracy and efficiency of the yaw acceleration of the airplane and the airborne equipment under the working condition.

[0090] As shown in Figure 1 The airplane emergency landing yaw acceleration analysis method provided by the present application comprises the following steps:

[0091] Step S10: establishing a yaw acceleration analysis model under the airplane emergency landing working condition.

[0092] As shown in Figure 1An acceleration analysis model in an emergency landing working condition of an airplane in an embodiment of the present application is shown, wherein the total mass of the airplane body excluding the airborne equipment is m1, the mass of the airborne equipment is m2, the connection stiffness between the airplane body and the airborne equipment is k1 and k2; only the horizontal motion is considered, wherein the initial horizontal velocity of the airplane body impacting the barrier is V, the horizontal displacement of the airplane body is x1, and the horizontal displacement of the airborne equipment is x2; the damping between the airplane body and the airborne equipment is ignored, and the influence factors such as the ground friction and the aerodynamic resistance are ignored.

[0093] According to Figure 1 The kinetic equation of the whole airplane is established according to the acceleration analysis model, wherein the kinetic energy T of the whole airplane is: (1)

[0094] In the formula, V is the horizontal velocity of the airplane body; V2 is the horizontal velocity of the airborne equipment.

[0095] The potential energy U of the whole airplane is: (2)

[0096] According to the Lagrange equation: (3)

[0097] The dynamic response equation of the whole airplane is:

[0098] (4)

[0099] In the formula, F is the horizontal force when the airplane body impacts the barrier, a1 is the horizontal acceleration response of the airplane body; a2 is the horizontal acceleration response of the airborne equipment. According to the Hertz contact theory, the calculation formula of the impact force of the whole airplane is as follows:

[0100]

[0101] (5)

[0102] In the formula, K is the contact stiffness between the airplane body and the barrier; α is the impact index, usually taken as 1.5; λ is the damping coefficient, and the calculation formula is as follows: (6)

[0103] In the formula, c r is the recovery coefficient of the material, and in this embodiment, the aluminum alloy commonly used in the airplane structure is converted, and c r =0.75 is taken.

[0104] In order to solve formula (5), the airplane body and the airborne equipment are regarded as a whole, and according to the second Newton theorem, the following formula is obtained: ​​(7)

[0105] Substituting equation (5) into equation (7) and rearranging, we get:

[0106] (8)

[0107] The horizontal displacement of the body is obtained by solving equation (8). and horizontal speed Then, substituting into equation (5) will give the collision force. Finally, the overall dynamic response of the aircraft is solved according to equation (4) to obtain the horizontal acceleration response of the airborne equipment. This allows us to obtain the magnitude of the directional acceleration of the airborne equipment.

[0108] It should be noted that regardless of whether the airborne equipment is installed forward-facing between the airborne equipment and the aircraft (i.e., ... Figure 2 The connection stiffness is set at the front side in the forward direction (or the rearward installation method). Figure 3 (The width of the connection is set on the rear side of the forward direction). The above-mentioned heading acceleration analysis model under the emergency landing condition of the aircraft is applicable.

[0109] Step S20: Obtain the values ​​of the parameters required by the above analysis model in the emergency landing heading acceleration analysis of the aircraft.

[0110] According to the aircraft emergency landing heading acceleration analysis model established in step S10, to calculate the heading acceleration of the computer body and onboard equipment, it is necessary to obtain the values ​​of the eight parameters shown in Table 1. Table 1 illustrates the methods for obtaining each parameter. In this embodiment of the application, exemplary values ​​of the eight parameters are also given in Table 1.

[0111] Table 1. Parameters required for heading acceleration analysis during aircraft emergency landing.

[0112] Serial number Parameter symbol Dimension Parameter value Remark 1 m1 kg 119000 Obtained from the calculation result of the aircraft weight 2 m2 kg 1000 Obtained from the calculation result or measured result of the equipment weight 3 ​ N / m 5 x 10 7 ]] Obtained by modeling simulation analysis of the connecting stiffness between the aircraft body and the equipment or the measured connecting stiffness between the aircraft body and the equipment 4 <k2> N / m 5 x 10 7 ]] Obtained by modeling simulation analysis of the connecting stiffness between the aircraft body and the equipment or the measured connecting stiffness between the aircraft body and the equipment 5 V m / s 50 Take the statistical value of the aircraft speed when rushing off the runway (10 m / s~50 m / s) 6 K N / m 1 x 10 6 ]] Obtained by modeling simulation analysis 7 α / 1.5 1.5 (recommended value) 8 c r ]]> / 0.75 0.75 (recommended value)

[0113] Step S30: Based on the azimuth acceleration analysis model and parameter numerical calculation, obtain the time history of the azimuth acceleration under the emergency landing condition of the aircraft.

[0114] Since the collision process shown in equation (8) is a highly nonlinear equation, only the numerical integration method can be used to solve for the horizontal displacement of the body. and horizontal speed of the machine body For the time history, this application preferably uses the fourth-order Runge-Kutta method for solution, and the specific calculation formulas are shown in equations (9) and (10). The initial conditions are: , The preferred time step is 0.001s, and the calculation time is not less than 1s.

[0115] (9)

[0116] (10)

[0117] In the formula, k1, k2, k3, and k4 are the process parameters of the fourth-order Runge-Kutta method, and t i x is a time variable i Let y be the displacement variable. i Let be the velocity variable, with the subscript i indicating the i-th time step, and Δt being the time step size.

[0118] In this embodiment of the application, the initial conditions are set as follows: , The time step is set to 0.001s, and the calculation time is 1s, thus obtaining the following... Figure 5 The machine displacement over time is shown and as follows Figure 6 The figure shows the velocity of the machine over time. Figure 5 The displacement of the body over time is shown as follows: Figure 6 Substituting the time history of the body velocity shown and the relevant parameter values ​​in Table 1 into equation (5), the time history of the body collision force F1(t) can be calculated, as follows: Figure 7 .

[0119] After obtaining the collision force F1(t), numerical integration methods such as the central difference method, Wilson-θ method, and Newmark method can be used to solve equation (4). It is recommended to take a time step of 0.001s and a calculation time of not less than 1s to obtain the acceleration response of the body. and the acceleration response of airborne equipment Extracting the body's acceleration response and the acceleration response of airborne equipment The maximum value is used as the design acceleration metric for the airframe and airborne equipment.

[0120] For example, in this embodiment of the application, the Newmark numerical integration method is used to solve equation (4), Figure 7 Substituting the time history of the collision force shown and the relevant parameter values ​​in Table 1 into equation (4), the acceleration response time history of the computer-borne equipment is obtained, with the initial conditions set as follows: , With a time step of 0.001s and a calculation duration of 1s, the calculated acceleration response time history of the airborne equipment is as follows: Figure 8 As shown. By extracting Figure 8 The peak value of the acceleration response time history of the airborne equipment shown (27.2g) is used as the design reference value for the forward acceleration of the airborne equipment.

[0121] In the present application, the design reference value A of the forward acceleration of the airborne equipment in the heading direction can be calculated by setting different aircraft runway overrun speeds (i.e. the initial horizontal speed V of the aircraft body impacting the obstacle), and the variation law of the design reference value A of the forward acceleration of the airborne equipment in the heading direction with the horizontal speed V can be further analyzed.

[0122] For example, in the present embodiment, the contact speed between the aircraft body and the obstacle can be set to 10 m / s, 20 m / s, 30 m / s, 40 m / s, and the rest of the parameters remain unchanged, the design reference value A of the forward acceleration of the airborne equipment in the heading direction corresponding to the speed can be calculated, and the calculation results are shown in Table 2. According to Table 2, with the increase of the aircraft runway overrun speed, the design reference value of the forward acceleration of the airborne equipment in the heading direction gradually increases, which conforms to the general law.

[0123] Table 2 Design reference value of forward acceleration of airborne equipment in heading direction corresponding to different aircraft runway overrun speeds

[0124] V / (m / s) 10 20 30 40 A / g 3.94 9.05 14.7 20.8

[0125] In addition, in the present application, the design reference value A of the forward acceleration of the airborne equipment in the heading direction corresponding to different contact stiffnesses K between the aircraft body and the obstacle can be calculated, and the variation law of A with K can be analyzed.

[0126] For example, in the present embodiment, the contact stiffness K between the aircraft body and the obstacle can be set to 2×10 6 N / m, 3×10 6 N / m, 4×10 6 N / m, 5×10 6 N / m, and the rest of the parameters remain unchanged, the design reference value A of the forward acceleration of the airborne equipment in the heading direction corresponding to the speed can be calculated, and the calculation results are shown in Table 3. According to Table 3, with the increase of the contact stiffness between the aircraft body and the obstacle, the design reference value of the forward acceleration of the airborne equipment in the heading direction gradually increases, which conforms to the general law.

[0127] Table 3 Design reference value of forward acceleration of airborne equipment in heading direction corresponding to different contact stiffnesses between aircraft body and obstacle

[0128] K / (N / m) 2 x 10 6 ]] 3 x 10 6 ]] 4 x 10 6 ]] 5 x 10 6 ]] A / g 35.9 42.4 47.6 51.8

[0129] From the above parameter variation analysis results, it can be seen that the design reference value of the forward acceleration of the airborne equipment in the heading direction calculated according to the present application is equivalent to the value specified in the relevant standard specifications (GJB 67.3A-2008, GJB 150.15A-2009, CCAR 25-R4), and the variation law is reasonable, which indicates that the method has certain feasibility and effectiveness.

[0130] The method of the application has clear ideas, sufficient theoretical basis, and can reasonably and effectively determine the heading acceleration of the aircraft body and airborne equipment during emergency landing, which has important guiding significance for aircraft structure and airborne equipment design. Compared with the general crash acceleration value specified in the standard specification, the application can carry out customized analysis according to the actual aircraft characteristics; compared with multi-body dynamics modeling and simulation analysis means, the implementation process of the application is simple and efficient.

[0131] On this basis, as shown in Figure 9 The application further provides an aircraft emergency landing heading acceleration analysis device 100, comprising:

[0132] A model component module 101 is configured to construct a heading acceleration analysis model under an aircraft emergency landing working condition.

[0133] A parameter acquisition module 102 is configured to acquire a value of a required parameter of the heading acceleration analysis model in an aircraft emergency landing heading acceleration analysis process.

[0134] A parameter calculation module 103 is configured to calculate a heading acceleration time history under the aircraft emergency landing working condition based on the value of the required parameter and the heading acceleration analysis model, and determine an acceleration design reference value of an airborne equipment heading forward based on the heading acceleration time history.

[0135] The processing procedures of the modules of the device can refer to the aircraft emergency landing heading acceleration analysis method described above, and will not be described here.

[0136] In addition, the application further provides an electronic device, which comprises:

[0137] One or more processors;

[0138] A memory;

[0139] One or more application programs stored in the memory and configured to be executed by the one or more processors, the one or more application programs being configured to implement the aircraft emergency landing heading acceleration analysis method according to any one of the above.

[0140] Finally, the application further provides a computer readable storage medium, characterized in that the computer readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by a processor to implement the aircraft emergency landing heading acceleration analysis method according to any one of the above.

[0141] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of analyzing acceleration of an emergency landing heading of an aircraft, characterized by, The application relates to a method for calculating the acceleration of an airborne device in the heading direction of an airplane in an emergency landing condition. The method comprises the following steps: constructing an acceleration analysis model of the airplane in the emergency landing condition; obtaining the numerical value of a parameter required by the acceleration analysis model of the airplane in the emergency landing condition; 2. The method of claim 1, wherein, calculating the time history of the acceleration of the airplane in the emergency landing condition based on the numerical value of the parameter and the acceleration analysis model, and determining the acceleration design reference value of the airborne device in the heading direction of the airplane based on the time history of the acceleration. The process of constructing the acceleration analysis model of the airplane in the emergency landing condition comprises the following steps: establishing the dynamic equation of the airplane as a whole, wherein the dynamic equation comprises the kinetic energy equation and the potential energy equation of the airplane as a whole; obtaining the dynamic response equation of the airplane as a whole based on the Lagrange equation, 3. The method of claim 2, wherein, The kinetic equation is: ; constructing the collision force calculation model of the airplane as a whole based on the Hertz contact theory, obtaining the collision force by solving the collision force calculation model of the airplane as a whole, and obtaining the horizontal acceleration response time history of the airborne device by solving the dynamic response equation of the airplane as a whole based on the collision force. In the formula, T is the kinetic energy of the airplane as a whole; m1 is the total mass of the airplane body except the airborne device; Vh is the horizontal velocity of the body; Vh is the horizontal velocity of the airborne device.

4. The method of claim 3, wherein, The potential energy equation is: m2 is the mass of the airborne device. In the formula, U is the potential energy of the airplane as a whole; k1 and k2 are the connecting stiffness between the airplane body and the airborne device respectively; x1(t) is the horizontal displacement of the airplane body; 5. The method of claim 4, wherein, x2(t) is the horizontal displacement of the airborne device. （4） wherein: is the horizontal force of the body when colliding with an obstacle, is the horizontal acceleration response of the body; is the horizontal acceleration response of the on-board equipment.

6. The method of claim 5, wherein, The dynamic response equation of the airplane as a whole is as follows: The collision force calculation model of the airplane as a whole is as follows:

7. The method of claim 6, wherein, the damping coefficient where: c r is the coefficient of restitution of the material and V is the initial horizontal velocity of the vehicle impacting the barrier.

8. The method of claim 3-7, wherein, In the formula, K is the contact stiffness between the airplane body and the obstacle; alpha is the collision index; and lambda is the damping coefficient. The process of solving the collision force calculation model of the airplane as a whole to obtain the collision force comprises the following steps: The time histories of the horizontal displacement of the fuselage and the horizontal velocity of the fuselage are obtained by solving the rearranged collision motion equation based on the numerical integration method, and the time histories of the horizontal displacement of the fuselage and the horizontal velocity of the fuselage are brought into the calculation model of the overall collision force of the aircraft to obtain the collision force.

9. The method of claim 8, wherein, The colliding motion equation after the arrangement is: .

10. The method of claim 9, wherein, the airplane body and the airborne device are regarded as a whole, the collision force calculation model of the airplane as a whole is arranged according to the second Newton theorem, and the arranged collision motion equation is obtained; 11. The method of claim 10, wherein the method further comprises: the numerical integral method comprises the fourth-order Runge-Kutta method, the initial condition, the time step and the calculation time length are determined, and the displacement of the airplane body with time and the speed of the airplane body with time are obtained.

12. An aircraft emergency landing heading acceleration analysis device, characterized by, The peak value of the horizontal acceleration response time history of the airborne device is extracted, and the peak value is the acceleration design reference value of the airborne device in the heading direction of the airplane. The application further relates to a device for calculating the acceleration of an airborne device in the heading direction of an airplane in an emergency landing condition. The device comprises the following modules: a model component module for constructing an acceleration analysis model of the airplane in the emergency landing condition; 13. The aircraft emergency landing direction acceleration analyzing apparatus of claim 12, wherein a parameter acquisition module for obtaining the numerical value of a parameter required by the acceleration analysis model of the airplane in the emergency landing condition; a parameter calculation module for calculating the time history of the acceleration of the airplane in the emergency landing condition based on the numerical value of the parameter and the acceleration analysis model, and determining the acceleration design reference value of the airborne device in the heading direction of the airplane based on the time history of the acceleration. The process of constructing the acceleration analysis model of the airplane in the emergency landing condition by the model component module comprises the following steps: establishing the dynamic equation of the airplane as a whole, wherein the dynamic equation comprises the kinetic energy equation and the potential energy equation of the airplane as a whole; obtaining the dynamic response equation of the airplane as a whole based on the Lagrange equation, The aircraft overall collision force calculation model is constructed based on the Hertz contact theory, the collision force is obtained by solving the aircraft overall collision force calculation model, and the horizontal acceleration response time history of the airborne equipment is obtained by solving the dynamic response equation of the aircraft overall based on the collision force.

14. The aircraft emergency landing direction acceleration analyzing apparatus of claim 13, wherein, The kinetic equation is: ; In the formula, T is the kinetic energy of the aircraft overall; m1 is the total mass of the aircraft body excluding the airborne equipment; m2 is the mass of the airborne equipment; Vh is the horizontal velocity of the body; Vh is the horizontal velocity of the airborne device.

15. The aircraft emergency landing direction acceleration analysis apparatus of claim 14, wherein, The potential energy equation is: In the formula, U is the potential energy of the aircraft overall; k1 and k2 are the connection stiffness between the aircraft body and the airborne equipment, respectively; x1(t) is the horizontal displacement of the aircraft body; x2(t) is the horizontal displacement of the airborne equipment.

16. The aircraft emergency landing direction acceleration analysis apparatus of claim 15, wherein, The dynamic response equation of the aircraft overall is: （4） wherein: is the horizontal force of the body when colliding with an obstacle, is the horizontal acceleration response of the body; is the horizontal acceleration response of the on-board equipment.

17. The aircraft emergency landing direction acceleration analysis apparatus of claim 16, wherein The aircraft overall collision force calculation model is: In the formula: K is the contact stiffness between the aircraft body and the obstacle; α is the collision index; and λ is the damping coefficient.

18. The method of claim 17, wherein, the damping coefficient where: c r is the coefficient of restitution of the material and V is the initial horizontal velocity of the vehicle impacting the barrier.

19. Apparatus for analyzing the acceleration of an aircraft emergency landing heading according to any one of claims 14 to 18, characterized in that, The process of solving the aircraft overall collision force calculation model to obtain the collision force is: The aircraft body and the airborne equipment are regarded as a whole, the aircraft overall collision force calculation model is arranged according to Newton's second law, and the arranged collision motion equation is obtained. The time histories of the horizontal displacement of the fuselage and the horizontal velocity of the fuselage are obtained by solving the rearranged collision motion equation based on the numerical integration method, and the time histories of the horizontal displacement of the fuselage and the horizontal velocity of the fuselage are brought into the calculation model of the overall collision force of the aircraft to obtain the collision force.

20. The aircraft emergency landing direction acceleration analysis apparatus of claim 19, wherein, The colliding motion equation after the arrangement is: .

21. The aircraft emergency landing direction acceleration analyzing apparatus of claim 20, wherein, The numerical integration method includes the fourth-order Runge-Kutta method, the initial conditions, the time step and the calculation time length are determined, and the displacement of the aircraft body with time and the speed of the aircraft body with time are obtained.

22. The aircraft emergency landing direction acceleration analysis apparatus of claim 21, wherein, The peak value of the horizontal acceleration response time history of the airborne equipment is extracted, and the peak value is the acceleration design reference value of the airborne equipment in the forward direction.

23. An electronic device, comprising: It comprises: One or more processors; Memory; One or more application programs stored in the memory and configured to be executed by the one or more processors, the one or more application programs being configured to implement the aircraft emergency landing heading acceleration analysis method according to any one of claims 1-11.

24. A computer-readable storage medium, characterized in that, The computer readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, which is loaded and executed by the processor to implement the aircraft emergency landing heading acceleration analysis method according to any one of claims 1-11.

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