Landing gear landing load calculation method and device

Abstract

The application relates to the technical field of landing gear load calculation, and discloses a landing gear landing load calculation method and device, which comprises the following steps: simplifying a buffer of a landing gear into a two-mass system to obtain an upper mass of an outer cylinder of the buffer and a lower mass of a piston rod, and constructing a target landing relationship function of the buffer according to the upper mass of the outer cylinder and the lower mass of the piston rod; constructing a motion state load function of the buffer, substituting the motion state load function into the target landing relationship function to solve, and obtaining a maximum vertical load parameter of the buffer; determining other load parameters of the buffer according to the maximum vertical load parameter, and determining landing load parameters of the landing gear according to the maximum vertical load parameter and the other load parameters. In this way, the reliability and accuracy of landing gear landing load calculation are improved through the two-mass system model of the landing gear; meanwhile, the landing gear landing load calculation process is simplified, so that the landing load calculation efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of landing gear load calculation technology, and in particular to a method and apparatus for calculating landing gear landing load. Background Technology

[0002] Modern aircraft landing gear commonly employs hydropneumatic dampers. These dampers utilize the compressibility of gas to store energy, while simultaneously absorbing landing impact energy through the high-speed flow of hydraulic fluid through damping orifices, resulting in excellent shock absorption performance. In existing simulation research and design processes for landing gear damping performance, the conventional procedure is as follows: based on model design experience, the damper damping curve and static compression curve are initially determined; subsequently, a rigid body model of the landing gear is constructed in dynamics software for simulation analysis; through multiple iterative optimizations, the damper load curve is made as full as possible to ensure maximum energy absorption within the structural stroke, thereby determining reasonable initial gas filling pressure, gas chamber / hydraulic chamber volume, main anti-reverse hydraulic orifice area, and other damper parameters, as well as landing gear structural parameters.

[0003] Currently, numerous factors influence the landing gear landing time load curve, including aircraft equivalent mass, descent velocity, and landing angle. During the landing gear design phase, dynamic load calculations and verifications of the buffer system are necessary, placing high demands on the accuracy and complexity of the buffer's mechanical model. However, existing landing gear buffer performance simulation calculations have significant shortcomings: firstly, they require specialized simulation software to build the buffer dynamic model, which has a high operational threshold; secondly, simplifying the buffer into a combination of nonlinear springs and damping forces leads to poor accuracy in landing load calculations. Therefore, a technical solution to improve the accuracy of landing gear landing load calculations is urgently needed. Summary of the Invention

[0004] This invention provides a method and apparatus for calculating landing gear landing loads. By using a two-mass system model of the landing gear, the reliability and accuracy of landing gear landing load calculations are improved. At the same time, the landing gear landing load calculation process is simplified, thereby improving the efficiency of landing load calculation.

[0005] To address the aforementioned technical problems, the first aspect of this invention discloses a method for calculating landing gear landing loads, the method comprising: The landing gear buffer is simplified by two masses to obtain the upper mass of the outer cylinder and the lower mass of the piston rod. Based on the upper mass of the outer cylinder and the lower mass of the piston rod, the target landing relationship function of the buffer is constructed. Construct the motion state load function of the buffer, and substitute the motion state load function into the target landing relationship function to solve for the maximum vertical load parameter of the buffer. Based on the maximum vertical load parameter, other load parameters of the buffer are determined, and based on the maximum vertical load parameter and the other load parameters, the landing load parameters of the landing gear are determined.

[0006] As an optional implementation, in the first aspect of the present invention, the target landing relationship function of the buffer includes the overall motion function of the buffer, the instantaneous landing function of the lower mass of the piston rod upon contact with the ground, the landing function of the upper mass of the outer cylinder during compression, and the landing function of the lower mass of the piston rod during compression. The step of constructing the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod includes: Based on the upper mass of the outer cylinder of the buffer, the lower mass of the piston rod, the preset vertical load parameters of the landing gear tires, and the lift parameters of the upper mass of the outer cylinder, the overall motion function of the buffer is constructed. Based on the motion state load function of the buffer, the vertical load parameters of the tire, and the mass of the lower part of the piston rod, a landing function for the instantaneous compression upon contact with the ground of the lower part of the piston rod is constructed. Based on the motion state load function, the lift parameters, and the upper mass of the outer cylinder, a landing function for the compression process of the upper mass of the outer cylinder is constructed. Based on the motion state load function, the tire vertical load parameters, and the lower mass of the piston rod, a landing function for the compression process of the lower mass of the piston rod is constructed.

[0007] As an optional implementation, in the first aspect of the present invention, the overall motion function of the buffer is: ; Where m is the lower mass of the piston rod, M is the upper mass of the outer cylinder, and a M Let a be the acceleration of the upper mass of the outer cylinder. m The acceleration of the lower mass of the piston rod, F v L is the vertical load parameter of the tire, g is the lift parameter, and g is the gravity coefficient. The instantaneous landing function upon contact compression is: m*a m =F v -F s -mg; Among them, F s The motion state load function of the buffer; The landing function for the compression process of the upper part of the outer cylinder is: M*a M =F s+L-Mg; The landing function for the compression process of the lower mass of the piston rod is: m*a m =F v -F s -mg.

[0008] As an optional implementation, in the first aspect of the invention, constructing the motion state load function of the buffer includes: The initial filling pressure parameters, initial volume parameters, stroke parameters, and piston rod outer diameter area parameters of the buffer are obtained, and the air chamber pressure function of the buffer is constructed by combining them with a preset gas polyvariance index. The oil density parameter, piston rod inner diameter area parameter, forward stroke main oil orifice flow coefficient, main oil orifice area parameter, and reverse stroke main oil orifice flow coefficient of the buffer are obtained, and combined with the preset compression speed parameter of the buffer, the pressure difference damping force function between the main oil chamber and the air chamber of the buffer is constructed. Obtain the inner diameter area parameters of the outer cylinder of the buffer, the flow coefficient of the return oil hole during the forward stroke, the area parameters of the return oil hole during the forward stroke, the flow coefficient of the return oil hole during the reverse stroke, and the area parameters of the return oil hole during the reverse stroke. Combine these with the outer diameter area parameters of the piston rod and the compression speed parameters to construct the pressure difference damping force function between the air chamber and the return oil chamber of the buffer. The motion state load function of the buffer is constructed based on the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber.

[0009] As an optional implementation, in the first aspect of the present invention, the air chamber pressure function of the buffer is: ; Wherein, P0 is the initial filling pressure parameter, V0 is the initial volume parameter of the air cavity, S is the stroke parameter, A2 is the outer diameter area parameter of the piston rod, and n is the air adiabatic index; where S=Z M -Z m , , v M v is the velocity parameter of the mass moving at the top of the outer cylinder. m The velocity parameter of the mass at the bottom of the piston rod is t, and the preset time parameter is t. The damping force function of the pressure difference between the main oil chamber and the air chamber of the buffer is: ; Where ρ is the oil density parameter, A3 is the piston rod inner diameter area parameter, and C dpHere, f is the flow coefficient of the main oil orifice during the positive stroke, f is the area parameter of the main oil orifice, and C is the flow coefficient of the main oil orifice during the positive stroke. dn Let v be the flow coefficient of the reverse stroke main oil orifice, and v be the compression speed parameter of the buffer; where v = v M -v m ; The damping force function of the pressure difference between the air chamber and the return oil chamber of the buffer is: ; Where A1 is the inner diameter area parameter of the outer cylinder, C drp f is the flow coefficient of the positive stroke return oil hole. rp C is the area parameter of the positive stroke return oil hole. drn f is the flow coefficient of the reverse stroke return oil hole. rn The area parameter of the reverse stroke return oil hole; The motion state load function of the buffer is: F s = F a + △P h-a + △P a-r ; Among them, F a = A2*(P) a -P atm ), P atm These are the preset atmospheric pressure parameters.

[0010] As an optional implementation, in the first aspect of the present invention, the step of substituting the motion state load function into the target landing relationship function for solution to obtain the maximum vertical load parameter of the buffer includes: Substitute the motion state load function into the target landing relationship function to obtain the substituted function, and simplify the substituted function to obtain the simplified function. The simplified function is transformed by ordinary differential equation to obtain the transformed function, and the transformed function is solved to obtain the numerical solution of the motion velocity parameters of the lower mass of the piston rod. Based on the numerical solution, the time-displacement curve of the lower mass of the piston rod is determined, and based on the preset tire stiffness parameters of the buffer, the time-tire load curve of the lower mass of the piston rod is determined, so as to determine the maximum vertical load parameter of the buffer through the time-tire load curve. The simplified function is: ; K is the preset tire stiffness parameter of the buffer; The deformed function is: ; The time-tire load curve of the lower mass of the piston rod can be determined by the following formula: .

[0011] As an optional implementation, in the first aspect of the invention, the initial filling pressure parameter of the buffer is determined by the following method: Based on the preset statically determinate air chamber pressure function, statically determinate main oil chamber pressure function, and statically determinate return oil chamber pressure function of the buffer, and combined with the outer cylinder inner diameter area parameter, piston rod outer diameter area parameter, piston rod inner diameter area parameter and atmospheric pressure parameter of the buffer, the statically determinate state load function of the buffer is constructed. Determine the instantaneous landing correlation between the statically determinate air chamber pressure function, the statically determinate main oil chamber pressure function, the statically determinate return oil chamber pressure function, and the initial filling pressure parameter of the buffer; and calculate the initial filling pressure parameter of the buffer based on the instantaneous landing correlation and the statically determinate state load function. The statically determinate load function of the buffer is: F' s = P' a *(A1-A3)+ P h *A3- P r *(A1-A2)- P atm *A2; P' a Let P be the pressure function of the statically determinate air chamber. h Let P be the pressure function of the statically determinate main oil chamber. r The pressure function of the statically determinate return oil chamber; The landing instant correlation is: P' a = P h = P r = P0.

[0012] A second aspect of the present invention discloses a landing gear landing load calculation device, the device comprising: A simplification module is used to perform a two-mass simplification on the landing gear buffer to obtain the upper mass of the outer cylinder and the lower mass of the piston rod of the buffer; The construction module is used to construct the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod; and to construct the motion state load function of the buffer. The solution module is used to substitute the motion state load function into the target landing relationship function for solution to obtain the maximum vertical load parameter of the buffer; The determination module is used to determine other load parameters of the buffer based on the maximum vertical load parameter, and to determine the landing load parameters of the landing gear based on the maximum vertical load parameter and the other load parameters.

[0013] As an optional implementation, in a second aspect of the present invention, the target landing relationship function of the buffer includes the overall motion function of the buffer, the instantaneous landing function of the lower mass of the piston rod upon contact with the ground, the landing function of the upper mass of the outer cylinder during compression, and the landing function of the lower mass of the piston rod during compression. Specifically, the method by which the construction module constructs the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod includes: Based on the upper mass of the outer cylinder of the buffer, the lower mass of the piston rod, the preset vertical load parameters of the landing gear tires, and the lift parameters of the upper mass of the outer cylinder, the overall motion function of the buffer is constructed. Based on the motion state load function of the buffer, the vertical load parameters of the tire, and the mass of the lower part of the piston rod, a landing function for the instantaneous compression upon contact with the ground of the lower part of the piston rod is constructed. Based on the motion state load function, the lift parameters, and the upper mass of the outer cylinder, a landing function for the compression process of the upper mass of the outer cylinder is constructed. Based on the motion state load function, the tire vertical load parameters, and the lower mass of the piston rod, a landing function for the compression process of the lower mass of the piston rod is constructed.

[0014] As an optional implementation, in a second aspect of the invention, the overall motion function of the buffer is: ; Where m is the lower mass of the piston rod, M is the upper mass of the outer cylinder, and a M Let a be the acceleration of the upper mass of the outer cylinder. m The acceleration of the lower mass of the piston rod, F v L is the vertical load parameter of the tire, g is the lift parameter, and g is the gravity coefficient. The instantaneous landing function upon contact compression is: m*a m =F v -F s -mg; Among them, F s The motion state load function of the buffer; The landing function for the compression process of the upper part of the outer cylinder is: M*a M =Fs +L-Mg; The landing function for the compression process of the lower mass of the piston rod is: m*a m =F v -F s -mg.

[0015] As an optional implementation, in the second aspect of the present invention, the method by which the construction module constructs the motion state load function of the buffer specifically includes: The initial filling pressure parameters, initial volume parameters, stroke parameters, and piston rod outer diameter area parameters of the buffer are obtained, and the air chamber pressure function of the buffer is constructed by combining them with a preset gas polyvariance index. The oil density parameter, piston rod inner diameter area parameter, forward stroke main oil orifice flow coefficient, main oil orifice area parameter, and reverse stroke main oil orifice flow coefficient of the buffer are obtained, and combined with the preset compression speed parameter of the buffer, the pressure difference damping force function between the main oil chamber and the air chamber of the buffer is constructed. Obtain the inner diameter area parameters of the outer cylinder of the buffer, the flow coefficient of the return oil hole during the forward stroke, the area parameters of the return oil hole during the forward stroke, the flow coefficient of the return oil hole during the reverse stroke, and the area parameters of the return oil hole during the reverse stroke. Combine these with the outer diameter area parameters of the piston rod and the compression speed parameters to construct the pressure difference damping force function between the air chamber and the return oil chamber of the buffer. The motion state load function of the buffer is constructed based on the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber.

[0016] As an optional implementation, in a second aspect of the invention, the air chamber pressure function of the buffer is: ; Wherein, P0 is the initial filling pressure parameter, V0 is the initial volume parameter of the air cavity, S is the stroke parameter, A2 is the outer diameter area parameter of the piston rod, and n is the air adiabatic index; Where S=Z M -Z m , , v M v is the velocity parameter of the mass moving at the top of the outer cylinder. m The velocity parameter of the mass at the bottom of the piston rod is t, and the preset time parameter is t. The damping force function of the pressure difference between the main oil chamber and the air chamber of the buffer is: ; Where ρ is the oil density parameter, A3 is the piston rod inner diameter area parameter, and C dp Here, f is the flow coefficient of the main oil orifice during the positive stroke, f is the area parameter of the main oil orifice, and C is the flow coefficient of the main oil orifice during the positive stroke. dn Let v be the flow coefficient of the reverse stroke main oil orifice, and v be the compression speed parameter of the buffer; where v = v M -v m ; The damping force function of the pressure difference between the air chamber and the return oil chamber of the buffer is: ; Where A1 is the inner diameter area parameter of the outer cylinder, C drp f is the flow coefficient of the positive stroke return oil hole. rp C is the area parameter of the positive stroke return oil hole. drn f is the flow coefficient of the reverse stroke return oil hole. rn The area parameter of the reverse stroke return oil hole; The motion state load function of the buffer is: F s = F a + △P h-a + △P a-r ; Among them, F a = A2*(P) a -P atm ), P atm These are the preset atmospheric pressure parameters.

[0017] As an optional implementation, in the second aspect of the present invention, the method by which the solving module substitutes the motion state load function into the target landing relationship function to obtain the maximum vertical load parameter of the buffer specifically includes: Substitute the motion state load function into the target landing relationship function to obtain the substituted function, and simplify the substituted function to obtain the simplified function. The simplified function is transformed by ordinary differential equation to obtain the transformed function, and the transformed function is solved to obtain the numerical solution of the motion velocity parameters of the lower mass of the piston rod. Based on the numerical solution, the time-displacement curve of the lower mass of the piston rod is determined, and based on the preset tire stiffness parameters of the buffer, the time-tire load curve of the lower mass of the piston rod is determined, so as to determine the maximum vertical load parameter of the buffer through the time-tire load curve. The simplified function is: ; K is the preset tire stiffness parameter of the buffer; The deformed function is: ; The time-tire load curve of the lower mass of the piston rod can be determined by the following formula: .

[0018] As an optional implementation, in a second aspect of the invention, the initial filling pressure parameter of the buffer is determined by the following method: Based on the preset statically determinate air chamber pressure function, statically determinate main oil chamber pressure function, and statically determinate return oil chamber pressure function of the buffer, and combined with the outer cylinder inner diameter area parameter, piston rod outer diameter area parameter, piston rod inner diameter area parameter and atmospheric pressure parameter of the buffer, the statically determinate state load function of the buffer is constructed. Determine the instantaneous landing correlation between the statically determinate air chamber pressure function, the statically determinate main oil chamber pressure function, the statically determinate return oil chamber pressure function, and the initial filling pressure parameter of the buffer; and calculate the initial filling pressure parameter of the buffer based on the instantaneous landing correlation and the statically determinate state load function. The statically determinate load function of the buffer is: F' s = P' a *(A1-A3)+ P h *A3- P r *(A1-A2)- P atm *A2; P' a Let P be the pressure function of the statically determinate air chamber. h Let P be the pressure function of the statically determinate main oil chamber. r The pressure function of the statically determinate return oil chamber; The landing instant correlation is: P' a = P h = P r = P0.

[0019] A third aspect of the present invention discloses another landing gear landing load calculation device, the device comprising: Memory containing executable program code; A processor coupled to the memory; The processor calls the executable program code stored in the memory to execute the landing gear landing load calculation method disclosed in the first aspect of the present invention.

[0020] The fourth aspect of the present invention discloses a computer storage medium storing computer instructions, which, when invoked, are used to execute the landing gear landing load calculation method disclosed in the first aspect of the present invention.

[0021] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: In this embodiment of the invention, the landing gear buffer is simplified using a two-mass model to obtain the upper mass of the outer cylinder and the lower mass of the piston rod. Based on these masses, a target landing relationship function for the buffer is constructed. A motion state load function for the buffer is then constructed and substituted into the target landing relationship function for solution, yielding the maximum vertical load parameter of the buffer. Based on this maximum vertical load parameter, other load parameters of the buffer are determined, and the landing gear landing load parameters are determined based on these parameters. This two-mass system model of the landing gear improves the reliability and accuracy of landing gear landing load calculation; simultaneously, it simplifies the landing gear landing load calculation process, thereby improving the efficiency of landing load calculation. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating a landing gear landing load calculation method disclosed in an embodiment of the present invention; Figure 2 This is a flowchart illustrating another landing gear landing load calculation method disclosed in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a landing gear landing load calculation device disclosed in an embodiment of the present invention; Figure 4 This is a schematic diagram of another landing gear landing load calculation device disclosed in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a two-mass system for a landing gear buffer disclosed in an embodiment of the present invention; Figure 6 This is a schematic diagram of the force analysis of the upper mass of the outer cylinder and the lower mass of the piston rod of a buffer disclosed in an embodiment of the present invention; Figure 7 This is a schematic diagram of the internal load analysis of a buffer disclosed in an embodiment of the present invention; Figure 8This is a schematic diagram of the time-tire load curve of the lower mass of the piston rod of a buffer disclosed in an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] This invention discloses a method and apparatus for calculating landing gear landing loads. By using a two-mass system model of the landing gear, the reliability and accuracy of landing gear landing load calculation are improved. At the same time, the landing gear landing load calculation process is simplified, thereby improving the efficiency of landing load calculation.

[0028] Example 1 Please see Figure 1 , Figure 1 This is a flowchart illustrating a landing gear landing load calculation method disclosed in an embodiment of the present invention. Optionally, this method can be implemented by a landing load calculation device, which can be integrated into a landing load calculation device (such as a host computer, intelligent computer, landing gear landing control platform, etc.), or it can be a local server or cloud server used to process the landing gear landing load calculation process, etc. The embodiments of the present invention do not impose limitations. Figure 1 As shown, the landing gear landing load calculation method may include the following operations: 101. The landing gear buffer is simplified to a two-mass system to obtain the upper mass of the outer cylinder and the lower mass of the piston rod. Based on the upper mass of the outer cylinder and the lower mass of the piston rod, the target landing relationship function of the buffer is constructed.

[0029] In embodiments of the present invention, such as Figure 5 As shown, the common strut-type landing gear landing model can be simplified to a two-mass system (this model does not consider the influence of internal friction of the buffer, and the load balance of the entire system is determined to be in the vertical direction; and the influence of yaw load on this model is not considered, making it suitable for buffers moving vertically). In this system, the upper mass of the buffer's outer cylinder can be simplified to M, and the lower mass of the buffer's piston rod can be simplified to m. In summary, the buffer can be simplified to a parallel combination model of nonlinear spring and hydraulic damping force, the tire can be simplified to a spring model, and the entire landing gear model can be simplified to two series systems.

[0030] Specifically, the target landing relationship function of the buffer includes the overall motion function of the buffer, the landing function of the mass at the moment of contact compression of the lower part of the piston rod, the landing function of the compression process of the upper part of the outer cylinder, and the landing function of the compression process of the lower part of the piston rod.

[0031] Furthermore, the landing gear landing compression process can be divided into two stages: The first stage is from the moment the wheels touch the ground to the moment the buffer begins to compress. Since the buffer is filled with high-pressure air, the upper mass M and the lower mass m are regarded as a single mass motion, from which the landing gear landing first stage equation can be established (including the overall motion function of the buffer and the landing function of the lower mass of the piston rod at the moment of ground contact compression); The second stage is after the buffer begins to compress, the buffer load is greater than the air spring force inside the buffer, and the buffer begins to compress, from which the landing gear landing second stage equation can be established (including the landing function of the compression process of the upper mass of the outer cylinder and the landing function of the compression process of the lower mass of the piston rod).

[0032] 102. Construct the motion state load function of the buffer, and substitute the motion state load function into the target landing relationship function to solve for the maximum vertical load parameter of the buffer.

[0033] In this embodiment of the invention, the solution process can first initialize the boundary conditions, such as the upper mass M of the outer cylinder and the lower mass m of the piston rod, and then substitute the motion state load function into the target landing relationship function, and apply the fourth-order Runge-Kutta algorithm or other numerical methods to solve the problem to obtain the maximum vertical load parameter of the buffer.

[0034] 103. Based on the maximum vertical load parameters, determine the other load parameters of the buffer, and based on the maximum vertical load parameters and other load parameters, determine the landing load parameters of the landing gear.

[0035] In this embodiment of the invention, optional other load parameters include at least one of the maximum takeoff load parameter, maximum rebound load parameter, and yaw landing load parameter. The empirical formulas for calculating the relationship between the other load parameters and the maximum vertical load parameter can be derived from GJB67.4-2008 "Structural Strength Specification for Military Aircraft - Part 4: Ground Loads" or GJB5435.3-2005 "Strength and Stiffness Specification for Unmanned Aerial Vehicles - Part 3: Ground Loads" to calculate the complete landing gear landing load parameters.

[0036] Furthermore, the yaw load from the obtained landing gear load parameters can be applied to the tire contact point, the vertical load to the wheel center, and the aerodynamic load (obtained through lift) to the buffer cavity. After iterative landing gear strength analysis, the final structural parameters and buffer filling parameters are selected to complete the landing gear design.

[0037] As can be seen, implementing the embodiments of the present invention simplifies the landing gear buffer to a two-mass configuration. Then, based on the obtained upper mass of the outer cylinder and lower mass of the piston rod, a target landing relationship function for the buffer is constructed. The constructed motion state load parameters of the buffer are then substituted into this function for solution, yielding the maximum vertical load parameters of the buffer, thereby determining the complete landing gear landing load parameters. Thus, by using a two-mass system model of the landing gear, the reliability and accuracy of landing gear landing load calculation are improved; simultaneously, the landing gear landing load calculation process is simplified, thereby improving the efficiency of landing load calculation.

[0038] By using a two-mass system model of the landing gear, the reliability and accuracy of landing gear landing load calculation are improved; at the same time, the landing gear landing load calculation process is simplified, which helps to improve the efficiency of landing load calculation.

[0039] In an optional embodiment, step 101 above, which involves constructing the target landing relationship function of the buffer based on the upper mass of the buffer's outer cylinder and the lower mass of the piston rod, includes: Based on the upper mass of the outer cylinder of the buffer, the lower mass of the piston rod, and the preset vertical load parameters of the landing gear tires and the lift parameters of the upper mass of the outer cylinder, the overall motion function of the buffer is constructed. Based on the buffer's motion state load function, tire vertical load parameters, and piston rod lower mass, a landing function for the piston rod lower mass at the moment of contact compression is constructed. Based on the motion state load function, lift parameters, and the mass of the upper part of the outer cylinder, a landing function for the compression process of the upper part of the outer cylinder is constructed. Based on the motion state load function, tire vertical load parameters, and piston rod lower mass, a landing function for the compression process of the piston rod lower mass is constructed.

[0040] In this optional embodiment, the motion state load function of the buffer is actually the load function to be constructed (which can be F). s (This is represented in the original text). Subsequently, it can be constructed based on the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber.

[0041] Specifically, the overall motion function of the buffer (at the instant the buffer is compressed upon contact with the ground, the upper mass M of the outer cylinder and the lower mass m of the piston rod can be considered as a single unit of motion) is: ; Where m is the mass of the lower part of the piston rod, M is the mass of the upper part of the outer cylinder, and a M The acceleration of the upper mass of the outer cylinder, a m The acceleration of the mass at the bottom of the piston rod, F v Here, F represents the tire's vertical load parameter, L represents the lift parameter, and g represents the gravity coefficient. It should be noted that F... v =(1+Cα)*Kβ =K*Z m C is the equivalent damping coefficient for vertical tire vibration, α is the tire deformation rate, K is the tire vertical stiffness, β is the tire deformation amount, and Z is the coefficient of friction. m This refers to the displacement parameters of the lower mass of the piston rod.

[0042] More specifically, the instantaneous landing function during touchdown compression is: m*a m =F v -F s -mg; Among them, F s Let be the load function of the buffer's motion state.

[0043] To be even more specific, through Figure 6 From the force analysis of the upper mass of the outer cylinder and the lower mass of the piston rod shown, we can derive the landing function for the compression process of the upper mass of the outer cylinder as follows: M*a M =F s +L-Mg; The landing function for the compression process of the lower mass of the piston rod is: m*a m =F v -F s -mg.

[0044] As can be seen, this optional embodiment can construct the overall motion function of the buffer using the upper mass of the outer cylinder, the lower mass of the piston rod, and preset vertical load parameters of the landing gear tires and lift parameters of the upper mass of the outer cylinder; it can construct the instantaneous landing function of the lower mass of the piston rod at ground contact compression based on the motion state load function of the buffer, the vertical load parameters of the tires, and the lower mass of the piston rod; it can construct the landing function of the upper mass of the outer cylinder during compression based on the motion state load function, lift parameters, and the upper mass of the outer cylinder; and it can construct the landing function of the upper mass of the outer cylinder during compression based on the motion state load function, lift parameters, and the upper mass of the outer cylinder. In this way, compared with the traditional landing gear landing load calculation method (i.e., the design process of calculating load and analyzing structural strength based on relevant standards and empirical values, and iterating repeatedly), this embodiment is based on the landing gear two-mass system model, which is conducive to improving the simplification and accuracy of the construction of the overall motion function of the buffer, the landing function of the lower mass of the piston rod at the moment of ground contact compression, the landing function of the upper mass of the outer cylinder during compression, and the landing function of the lower mass of the piston rod during compression. This is conducive to improving the reliability and accuracy of the subsequent calculation of landing gear landing load parameters, and thus to improving the reliability and accuracy of the subsequent landing gear landing control.

[0045] In another optional embodiment, the construction of the motion state load function of the buffer in step 102 above includes: The initial filling pressure parameters, initial volume parameters, stroke parameters, and piston rod outer diameter area parameters of the buffer are obtained, and the air chamber pressure function of the buffer is constructed by combining the preset gas polyvariance index. The oil density parameter, piston rod inner diameter area parameter, main oil orifice flow coefficient, main oil orifice area parameter, and reverse main oil orifice flow coefficient of the buffer are obtained, and combined with the preset compression speed parameter of the buffer, the pressure difference damping force function between the main oil chamber and the air chamber of the buffer is constructed. The inner diameter area parameters of the outer cylinder of the buffer, the flow coefficient of the return oil hole during the forward stroke, the area parameters of the return oil hole during the forward stroke, the flow coefficient of the return oil hole during the reverse stroke, and the area parameters of the return oil hole during the reverse stroke are obtained. Combined with the outer diameter area parameters of the piston rod and the compression speed parameters, the pressure difference damping force function between the air chamber and the return oil chamber of the buffer is constructed. Based on the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber, the motion state load function of the buffer is constructed.

[0046] In this optional embodiment, further, such as Figure 7 As shown, based on the load analysis of the buffer's internal components, the air chamber pressure function of the buffer can be obtained as follows: ; Where P0 is the initial filling pressure parameter, V0 is the initial volume parameter of the air cavity, S is the stroke parameter, A2 is the piston rod outer diameter area parameter, and n is the air adiabatic index; where S=Z M -Z m , , v M v is the velocity parameter of the mass moving in the upper part of the outer cylinder. m t represents the velocity parameter of the mass moving at the bottom of the piston rod, and t is a preset time parameter.

[0047] Furthermore, the damping force function of the pressure difference between the main oil chamber and the air chamber of the buffer is: ; Where ρ is the oil density parameter, A3 is the piston rod inner diameter area parameter, and C dp Let f be the flow coefficient of the main oil orifice during the positive stroke, and C be the area parameter of the main oil orifice. dn Let v be the flow coefficient of the main oil orifice during the reverse stroke, and v be the compression speed parameter of the buffer; where v = v M -v m .

[0048] Furthermore, the damping force function of the pressure difference between the air chamber and the return oil chamber of the buffer is: ; Where A1 is the inner diameter area parameter of the outer cylinder, C drp f is the flow coefficient of the return oil hole during the positive stroke. rp C represents the area parameter of the return oil hole during the positive stroke. drn f is the flow coefficient of the reverse stroke return oil hole. rn This refers to the area parameter of the reverse stroke return oil hole.

[0049] And, the motion state load function of the buffer is: F s = F a + △P h-a + △P a-r ; Among them, F a = A2*(P) a -P atm ), P atm These are the preset atmospheric pressure parameters.

[0050] Specifically, F s F a , △P h-a , △P a-r It can be viewed as the axis load function corresponding to the second stage of landing gear landing - when the buffer begins to compress.

[0051] Furthermore, the initial filling pressure parameter of the buffer is determined in the following way: Based on the preset statically determinate air chamber pressure function, statically determinate main oil chamber pressure function, and statically determinate return oil chamber pressure function of the buffer, and combined with the buffer's outer cylinder inner diameter area parameter, piston rod outer diameter area parameter, piston rod inner diameter area parameter, and atmospheric pressure parameter, the statically determinate state load function of the buffer is constructed. The landing instantaneous correlation between the statically determinate air chamber pressure function, the statically determinate main oil chamber pressure function, the statically determinate return oil chamber pressure function and the initial filling pressure parameter of the buffer is determined, and the initial filling pressure parameter of the buffer is calculated based on the landing instantaneous correlation and the statically determinate state load function.

[0052] The statically determinate load function of the buffer is: F' s = P' a *(A1-A3)+ P h *A3- P r *(A1-A2)- P atm *A2; P' a P is a statically determinate air chamber pressure function. h P is the statically determinate main oil chamber pressure function. r The pressure function of the statically determinate return oil chamber; The correlation at the moment of landing is: P' a = P h = P r = P0.

[0053] Specifically, this landing moment correlation can be understood as follows: In the first stage of landing gear landing—the instant the buffer just touches the ground and has not yet been compressed—the pressure in the buffer's air chamber, main oil chamber, and return oil chamber is equal and equal to P0. At this time, the axial load can be considered as F. s ≤P0*A2.

[0054] As can be seen, this optional embodiment can first construct the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber of the buffer, and then determine the motion state load function based on these functions. This allows the motion state load function to closely match the variable characteristics of the gas and achieve accurate quantification of fluid effects, thereby improving the accuracy of the motion state load calculation for the buffer. It also allows the buffer to adapt to different design scenarios, enhancing application flexibility.

[0055] Example 2 Please see Figure 2 , Figure 2This is a flowchart illustrating another landing gear landing load calculation method disclosed in an embodiment of the present invention. Optionally, this method can be implemented by a landing load calculation device, which can be integrated into a landing load calculation device (such as a host computer, intelligent computer, landing gear landing control platform, etc.), or it can be a local server or cloud server used to process the landing gear landing load calculation process, etc., and the embodiments of the present invention do not limit it. Figure 2 As shown, the landing gear landing load calculation method may include the following operations: 201. The landing gear buffer is simplified to a two-mass system to obtain the upper mass of the outer cylinder and the lower mass of the piston rod. Based on the upper mass of the outer cylinder and the lower mass of the piston rod, the target landing relationship function of the buffer is constructed.

[0056] 202. Construct the motion state load function of the buffer, substitute the motion state load function into the target landing relationship function to obtain the substituted function, and simplify the substituted function to obtain the simplified function.

[0057] In this embodiment of the invention, the simplified function is: ; K is the preset tire stiffness parameter for the buffer.

[0058] Specifically, this embodiment can be understood as follows: First, the values ​​of the upper mass M of the outer cylinder of the landing gear buffer, the lower mass m of the piston rod, the air adiabatic index n, the oil density parameter ρ, the aircraft sinking speed v0, and the lift parameter L are initialized. Then, according to the preliminary design of the buffer, the relevant parameters of the buffer are filled into the motion state load function, including the inner diameter area parameter A1 of the outer cylinder, the area parameter f of the main oil hole, the effective area parameter (A1-A2) of the return oil chamber, the inner diameter area parameter A3 of the piston rod, and the area parameter f of the return oil hole during the forward stroke. rp Parameter f of the reverse stroke return oil hole area rn Piston rod outer diameter area parameter A2, initial air chamber volume parameter V0, initial filling pressure parameter P0, damper stroke parameter S, and main oil orifice flow coefficient C during the positive stroke. dp Flow coefficient C of the main oil orifice during reverse stroke dn Flow coefficient C of the return oil hole during forward stroke drp Flow coefficient C of the reverse stroke return oil hole drn Tire stiffness K and other values.

[0059] 203. Perform ordinary differential transformation on the simplified function to obtain the transformed function, and solve the transformed function to obtain the numerical solution of the velocity parameters of the mass at the bottom of the piston rod.

[0060] In this embodiment of the invention, the deformed function is: .

[0061] Alternatively, the transformed function can be solved using the fourth-order Runge-Kutta algorithm or other ordinary differential equation solving methods.

[0062] Specifically, the fourth-order Runge-Kutta algorithm is a numerical method for iteratively solving ordinary differential equations. It improves accuracy by calculating a weighted average of the slopes at multiple intermediate points. Its basic form is as follows: ; Where h is the step size, and in this algorithm, it is the time s, and k i The slope is calculated at different locations; δ is the order of calculation.

[0063] Furthermore, the iterative process of this fourth-order Runge-Kutta algorithm is as follows: Initialization state: t n ,state: Step size: h; Derivative function form: Then calculate the four slopes of the vector: Function update state: , By repeating the above process for each time step, the answer can be obtained step by step. , The numerical solution. The only parameter in the equation requiring iteration is the upper mass displacement Z of the buffer. M Upper mass velocity v M Lower mass displacement Z m Lower mass velocity v m With four parameters and time t as the iterative variable, the above equation of motion can be used to calculate the acceleration 'a' of the upper mass within a certain time precision. M and the acceleration a of the lower mass m Assuming the initial velocity is V0, i.e., the landing gear descent velocity, we calculate the change curves of various parameters within 1 second of landing gear landing. Since the landing gear landing process is relatively short, the time calculation precision is set to within 1 ms. We can use a fourth-order Runge-Kutta function to calculate the initial parameters with fourth-order derivative precision within 1 ms (or other time intervals). That is, the above motion equations are updated every 0.001 s, and the calculated values ​​are used as input to re-enter the next iteration. This process can be accomplished using a loop function.

[0064] 204. Based on the numerical solution, determine the time-displacement curve of the lower mass of the piston rod, and based on the preset tire stiffness parameters of the buffer, determine the time-tire load curve of the lower mass of the piston rod, so as to determine the maximum vertical load parameter of the buffer through the time-tire load curve.

[0065] In this embodiment of the invention, the time-tire load curve of the lower mass of the piston rod can be determined by the following formula: .

[0066] Among them, the time-tire load curve of the lower mass of the piston rod and the maximum vertical load parameter of the buffer can be obtained as follows: Figure 8 As shown.

[0067] 205. Based on the maximum vertical load parameters, determine the other load parameters of the buffer, and based on the maximum vertical load parameters and other load parameters, determine the landing load parameters of the landing gear.

[0068] In this embodiment of the invention, for other descriptions of steps 201 and 205, please refer to the detailed description of steps 101 and 103 in Embodiment 1. This embodiment of the invention will not repeat them.

[0069] As can be seen, implementing the embodiments of the present invention can comprehensively integrate the buffer structure, fluid, and gas characteristic parameters into the buffer's motion state load function. Then, after substituting these parameters into the objective function, simplification and ordinary differential transformation are performed, combined with the fourth-order Runge-Kutta algorithm or other algorithms for iterative solution, yielding a numerical solution for the motion velocity parameters of the lower mass of the piston rod. This allows for the determination of the buffer's maximum vertical load parameters and other load parameters. This eliminates redundant interference factors, significantly reduces the difficulty of building the mechanical model, and eliminates the need for complex professional simulation software, laying the foundation for subsequent rapid calculations. Simultaneously, it improves the accuracy of calculating the buffer's maximum vertical load parameters and other load parameters, thus adapting to different landing gear design scenarios under different conditions and improving design efficiency and economy.

[0070] In an optional embodiment, the method further includes: Obtain the maximum value of the stroke parameter, and determine the maximum air chamber pressure value of the buffer based on the maximum value of the stroke parameter and the air chamber pressure function of the buffer. Based on the maximum air chamber pressure value of the buffer, determine the maximum main oil chamber pressure value and the maximum return oil chamber pressure value of the buffer.

[0071] In this optional embodiment, the strength of the internal components of the buffer can be checked subsequently based on the maximum air chamber pressure value, the maximum main oil chamber pressure value, and the maximum return oil chamber pressure value.

[0072] It should be noted that during the second stage of landing gear landing, the shock absorber compresses, increasing the pressure in the air chamber. When the shock absorber compression rate reaches zero, the pressure in the three chambers (air chamber, main oil chamber, and return oil chamber) becomes equal and reaches its maximum value P. maxAt this point, when calculating the landing gear load, the Z-axis load is applied to the wheel mounting center, and the Y-axis and X-axis loads are applied to the tire contact points, with pressure P... max It is applied to the inner wall of the buffer. Furthermore, the maximum air chamber pressure of the buffer is: .

[0073] As can be seen, this optional embodiment can determine the maximum air chamber pressure value of the buffer based on the maximum value of the buffer's stroke parameters and the air chamber pressure function. Then, based on the maximum air chamber pressure value, it can determine the maximum main oil chamber pressure value and the maximum return oil chamber pressure value of the buffer. This compensates for the deficiency of traditional landing gear load calculations in neglecting the multi-chamber pressure peaks within the buffer, providing crucial and accurate pressure parameter support for the strength verification of the buffer's internal components. This effectively reduces problems of insufficient strength or structural redundancy in internal components caused by pressure estimation errors. Simultaneously, it clarifies the loading positions of different loads, making the strength verification more closely match actual stress scenarios, thereby ensuring the reliability of the landing gear structure and improving the accuracy and safety of the overall landing gear design.

[0074] Example 3 Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a landing gear landing load calculation device disclosed in an embodiment of the present invention. Figure 3 As shown, the landing gear landing load calculation device may include: The simplification module 301 is used to simplify the landing gear buffer into two masses to obtain the upper mass of the outer cylinder and the lower mass of the piston rod. Module 302 is used to construct the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod; and to construct the motion state load function of the buffer. The solver module 303 is used to substitute the motion state load function into the target landing relationship function for solving to obtain the maximum vertical load parameter of the buffer; The determination module 304 is used to determine other load parameters of the buffer based on the maximum vertical load parameter, and to determine the landing load parameters of the landing gear based on the maximum vertical load parameter and other load parameters.

[0075] In this embodiment of the invention, the target landing relationship function of the buffer includes the overall motion function of the buffer, the landing function of the mass at the moment of contact compression of the lower part of the piston rod, the landing function of the compression process of the upper part of the outer cylinder, and the landing function of the compression process of the lower part of the piston rod.

[0076] It is evident that implementation Figure 3The described landing gear landing load calculation device simplifies the landing gear buffer into a two-mass configuration. Then, based on the obtained upper mass of the outer cylinder and lower mass of the piston rod, it constructs a target landing relationship function for the buffer. Substituting the constructed motion state load parameters of the buffer into this function, it solves for the maximum vertical load parameters of the buffer, thereby determining the complete landing gear landing load parameters. This two-mass system model of the landing gear improves the reliability and accuracy of landing gear landing load calculation; simultaneously, it simplifies the calculation process, thus improving the efficiency of landing load calculation.

[0077] In an optional embodiment, the construction module 302 constructs the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod, specifically including: Based on the upper mass of the outer cylinder of the buffer, the lower mass of the piston rod, and the preset vertical load parameters of the landing gear tires and the lift parameters of the upper mass of the outer cylinder, the overall motion function of the buffer is constructed. Based on the buffer's motion state load function, tire vertical load parameters, and piston rod lower mass, a landing function for the piston rod lower mass at the moment of contact compression is constructed. Based on the motion state load function, lift parameters, and the mass of the upper part of the outer cylinder, a landing function for the compression process of the upper part of the outer cylinder is constructed. Based on the motion state load function, tire vertical load parameters, and piston rod lower mass, a landing function for the compression process of the piston rod lower mass is constructed.

[0078] In this optional embodiment, the overall motion function of the buffer is further: ; Where m is the mass of the lower part of the piston rod, M is the mass of the upper part of the outer cylinder, and a M The acceleration of the upper mass of the outer cylinder, a m The acceleration of the mass at the bottom of the piston rod, F v Here, L represents the tire vertical load parameter, g represents the lift parameter, and g represents the gravity coefficient. The instantaneous landing function during touchdown compression is: m*a m =F v -F s -mg; Among them, F s The load function is the motion state function of the buffer. The landing function for the compression process of the upper part of the outer cylinder is: M*a M =F s +L-Mg; The landing function for the compression process of the lower mass of the piston rod is: m*a m =F v -F s -mg.

[0079] It is evident that implementation Figure 3 The described landing gear landing load calculation device can construct the overall motion function of the buffer using the upper mass of the outer cylinder of the buffer, the lower mass of the piston rod, and preset vertical load parameters of the landing gear tires and lift parameters of the upper mass of the outer cylinder; it can construct the instantaneous landing function of the lower mass of the piston rod at ground contact compression based on the motion state load function of the buffer, the vertical load parameters of the tires, and the lower mass of the piston rod; it can construct the landing function of the compression process of the upper mass of the outer cylinder based on the motion state load function, lift parameters, and the upper mass of the outer cylinder; and it can construct the landing function of the compression process of the upper mass of the outer cylinder based on the motion state load function, lift parameters, and the upper mass of the outer cylinder. In this way, compared with the traditional landing gear landing load calculation method (i.e., the design process of calculating load and analyzing structural strength based on relevant standards and empirical values, and iterating repeatedly), this embodiment is based on the landing gear two-mass system model, which is conducive to improving the simplification and accuracy of the construction of the overall motion function of the buffer, the landing function of the lower mass of the piston rod at the moment of ground contact compression, the landing function of the upper mass of the outer cylinder during compression, and the landing function of the lower mass of the piston rod during compression. This is conducive to improving the reliability and accuracy of the subsequent calculation of landing gear landing load parameters, and thus to improving the reliability and accuracy of the subsequent landing gear landing control.

[0080] In another alternative embodiment, the construction module 302 constructs the motion state load function of the buffer in the following specific ways: The initial filling pressure parameters, initial volume parameters, stroke parameters, and piston rod outer diameter area parameters of the buffer are obtained, and the air chamber pressure function of the buffer is constructed by combining the preset gas polyvariance index. The oil density parameter, piston rod inner diameter area parameter, main oil orifice flow coefficient, main oil orifice area parameter, and reverse main oil orifice flow coefficient of the buffer are obtained, and combined with the preset compression speed parameter of the buffer, the pressure difference damping force function between the main oil chamber and the air chamber of the buffer is constructed. The inner diameter area parameters of the outer cylinder of the buffer, the flow coefficient of the return oil hole during the forward stroke, the area parameters of the return oil hole during the forward stroke, the flow coefficient of the return oil hole during the reverse stroke, and the area parameters of the return oil hole during the reverse stroke are obtained. Combined with the outer diameter area parameters of the piston rod and the compression speed parameters, the pressure difference damping force function between the air chamber and the return oil chamber of the buffer is constructed. Based on the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber, the motion state load function of the buffer is constructed.

[0081] In this optional embodiment, the air chamber pressure function of the buffer is further: ; Wherein, P0 is the initial filling pressure parameter, V0 is the initial volume parameter of the air cavity, S is the stroke parameter, A2 is the piston rod outer diameter area parameter, and n is the air adiabatic index; Where S=Z M -Z m , , v M v is the velocity parameter of the mass moving in the upper part of the outer cylinder. m t represents the velocity parameter of the mass at the bottom of the piston rod, and t is a preset time parameter. The damping force function of the pressure difference between the main oil chamber and the air chamber of the buffer is: ; Where ρ is the oil density parameter, A3 is the piston rod inner diameter area parameter, and C dp Let f be the flow coefficient of the main oil orifice during the positive stroke, and C be the area parameter of the main oil orifice. dn Let v be the flow coefficient of the main oil orifice during the reverse stroke, and v be the compression speed parameter of the buffer; where v = v M -v m ; The damping force function of the pressure difference between the air chamber and the return oil chamber of the buffer is: ; Where A1 is the inner diameter area parameter of the outer cylinder, C drp f is the flow coefficient of the return oil hole during the positive stroke. rp C represents the area parameter of the return oil hole during the positive stroke. drn f is the flow coefficient of the reverse stroke return oil hole. rn The area parameter for the reverse stroke return oil hole; The motion state load function of the buffer is: F s = F a + △P h-a + △P a-r ; Among them, F a = A2*(P) a -P atm ), P atm These are the preset atmospheric pressure parameters.

[0082] Furthermore, the initial filling pressure parameter of the buffer is determined in the following way: Based on the preset statically determinate air chamber pressure function, statically determinate main oil chamber pressure function, and statically determinate return oil chamber pressure function of the buffer, and combined with the buffer's outer cylinder inner diameter area parameter, piston rod outer diameter area parameter, piston rod inner diameter area parameter, and atmospheric pressure parameter, the statically determinate state load function of the buffer is constructed. Determine the instantaneous landing correlation between the statically determinate air chamber pressure function, the statically determinate main oil chamber pressure function, the statically determinate return oil chamber pressure function and the initial filling pressure parameter of the buffer, and calculate the initial filling pressure parameter of the buffer based on the instantaneous landing correlation and the statically determinate state load function. The statically determinate load function of the buffer is: F' s = P' a *(A1-A3)+ P h *A3- P r *(A1-A2)- P atm *A2; P' a P is a statically determinate air chamber pressure function. h P is the statically determinate main oil chamber pressure function. r The pressure function of the statically determinate return oil chamber; The correlation at the moment of landing is: P' a = P h = P r = P0.

[0083] It is evident that implementation Figure 3 The described landing gear landing load calculation device can first construct the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber of the buffer, and then determine the motion state load function based on these functions. This allows the motion state load function to closely reflect the variable characteristics of the gas and achieve precise quantification of fluid effects, thereby improving the accuracy of the buffer's motion state load calculation. It also allows the buffer to adapt to different design scenarios, enhancing application flexibility.

[0084] In another optional embodiment, the solution module 303 substitutes the motion state load function into the target landing relationship function for solution, and obtains the maximum vertical load parameter of the buffer in the following specific ways: Substitute the motion state load function into the target landing relationship function to obtain the substituted function, and then simplify the substituted function to obtain the simplified function. The simplified function is transformed by ordinary differential transformation to obtain the transformed function, and the transformed function is solved to obtain the numerical solution of the motion velocity parameters of the lower mass of the piston rod. Based on the numerical solution, the time-displacement curve of the lower mass of the piston rod is determined, and based on the preset tire stiffness parameters of the buffer, the time-tire load curve of the lower mass of the piston rod is determined. The maximum vertical load parameters of the buffer are then determined through the time-tire load curve.

[0085] In this optional embodiment, the simplified function is: ; K is the preset tire stiffness parameter for the buffer.

[0086] The transformed function is: .

[0087] The time-tire load curve of the lower piston rod mass can be determined by the following formula: .

[0088] It is evident that implementation Figure 3 The described landing gear landing load calculation device can comprehensively integrate the buffer structure, fluid, and gas characteristic parameters into the buffer's motion state load function. After substituting these parameters into the objective function, and through simplification and ordinary differential transformation, it iteratively solves the problem using the fourth-order Runge-Kutta algorithm or other algorithms to obtain the numerical solution for the velocity parameters of the lower mass of the piston rod. This allows for the determination of the buffer's maximum vertical load parameters and other load parameters. This eliminates redundant interference factors, significantly reduces the difficulty of building the mechanical model, and eliminates the need for complex professional simulation software, laying the foundation for subsequent rapid calculations. Simultaneously, it improves the accuracy of calculating the buffer's maximum vertical load parameters and other load parameters, thus adapting to different landing gear design scenarios under various operating conditions and improving design efficiency and economy.

[0089] In yet another alternative embodiment, the determining module 304 is further configured to: Obtain the maximum value of the stroke parameters, and determine the maximum air chamber pressure value of the buffer based on the maximum value of the stroke parameters and the air chamber pressure function of the buffer; determine the maximum main oil chamber pressure value and the maximum return oil chamber pressure value of the buffer based on the maximum air chamber pressure value of the buffer.

[0090] It is evident that implementation Figure 3The described landing gear landing load calculation device can determine the maximum air chamber pressure of the buffer based on the maximum value of the buffer's stroke parameters and the air chamber pressure function. Then, based on the maximum air chamber pressure, it can determine the maximum main oil chamber pressure and the maximum return oil chamber pressure. This compensates for the deficiency of traditional landing gear load calculations in neglecting the multi-chamber pressure peaks within the buffer, providing crucial and accurate pressure parameter support for the strength verification of the buffer's internal components. This effectively reduces problems such as insufficient strength or structural redundancy of internal components caused by pressure estimation errors. Simultaneously, it clarifies the loading positions of different loads, making the strength verification more closely resemble actual stress scenarios, thereby ensuring the reliability of the landing gear structure and improving the accuracy and safety of the overall landing gear design.

[0091] Example 4 Please see Figure 4 , Figure 4 This is a schematic diagram of another landing gear landing load calculation device disclosed in an embodiment of the present invention. Figure 4 As shown, the landing gear landing load calculation device may include: Memory 401 storing executable program code; Processor 402 coupled to memory 401; The processor 402 calls the executable program code stored in the memory 401 to execute the steps in the landing gear landing load calculation method described in Embodiment 1 or Embodiment 2 of the present invention.

[0092] Example 5 This invention discloses a computer storage medium storing computer instructions. When these computer instructions are invoked, they are used to execute the steps in the landing gear landing load calculation method described in Embodiment 1 or Embodiment 2 of this invention.

[0093] Example 6 This invention discloses a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to perform the steps in the landing gear landing load calculation method described in Embodiment 1 or Embodiment 2.

[0094] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0095] Through the detailed description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0096] Finally, it should be noted that the landing gear landing load calculation method and apparatus disclosed in the embodiments of the present invention are merely preferred embodiments of the present invention and are only used to illustrate the technical solutions of the present invention, not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating landing gear landing load, characterized in that, The method includes: The landing gear buffer is simplified by two masses to obtain the upper mass of the outer cylinder and the lower mass of the piston rod. Based on the upper mass of the outer cylinder and the lower mass of the piston rod, the target landing relationship function of the buffer is constructed. Construct the motion state load function of the buffer, and substitute the motion state load function into the target landing relationship function to solve for the maximum vertical load parameter of the buffer. Based on the maximum vertical load parameter, other load parameters of the buffer are determined, and based on the maximum vertical load parameter and the other load parameters, the landing load parameters of the landing gear are determined.

2. The landing gear landing load calculation method according to claim 1, characterized in that, The target landing relationship function of the buffer includes the overall motion function of the buffer, the instantaneous landing function of the mass at the ground contact compression of the lower part of the piston rod, the landing function of the compression process of the upper part of the outer cylinder, and the landing function of the compression process of the lower part of the piston rod. The step of constructing the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod includes: Based on the upper mass of the outer cylinder of the buffer, the lower mass of the piston rod, the preset vertical load parameters of the landing gear tires, and the lift parameters of the upper mass of the outer cylinder, the overall motion function of the buffer is constructed. Based on the motion state load function of the buffer, the vertical load parameters of the tire, and the mass of the lower part of the piston rod, a landing function for the instantaneous compression upon contact with the ground of the lower part of the piston rod is constructed. Based on the motion state load function, the lift parameters, and the upper mass of the outer cylinder, a landing function for the compression process of the upper mass of the outer cylinder is constructed. Based on the motion state load function, the tire vertical load parameters, and the lower mass of the piston rod, a landing function for the compression process of the lower mass of the piston rod is constructed.

3. The landing gear landing load calculation method according to claim 2, characterized in that, The overall motion function of the buffer is: ； Where m is the lower mass of the piston rod, M is the upper mass of the outer cylinder, and a M Let a be the acceleration of the upper mass of the outer cylinder. m The acceleration of the lower mass of the piston rod, F v L is the vertical load parameter of the tire, g is the lift parameter, and g is the gravity coefficient. The instantaneous landing function upon contact compression is: m*a m =F v -F s -mg;; Among them, F s The motion state load function of the buffer; The landing function for the compression process of the upper part of the outer cylinder is: M*a M =F s +L-Mg; The landing function for the compression process of the lower mass of the piston rod is: m*a m =F v -F s -mg。 4. The landing gear landing load calculation method according to claim 3, characterized in that, The motion state load function for constructing the buffer includes: The initial filling pressure parameters, initial volume parameters, stroke parameters, and piston rod outer diameter area parameters of the buffer are obtained, and the air chamber pressure function of the buffer is constructed by combining them with a preset gas polyvariance index. The oil density parameter, piston rod inner diameter area parameter, forward stroke main oil orifice flow coefficient, main oil orifice area parameter, and reverse stroke main oil orifice flow coefficient of the buffer are obtained, and combined with the preset compression speed parameter of the buffer, the pressure difference damping force function between the main oil chamber and the air chamber of the buffer is constructed. Obtain the inner diameter area parameters of the outer cylinder of the buffer, the flow coefficient of the return oil hole during the forward stroke, the area parameters of the return oil hole during the forward stroke, the flow coefficient of the return oil hole during the reverse stroke, and the area parameters of the return oil hole during the reverse stroke. Combine these with the outer diameter area parameters of the piston rod and the compression speed parameters to construct the pressure difference damping force function between the air chamber and the return oil chamber of the buffer. The motion state load function of the buffer is constructed based on the air chamber pressure function, the pressure difference damping force function between the main oil chamber and the air chamber, and the pressure difference damping force function between the air chamber and the return oil chamber.

5. The landing gear landing load calculation method according to claim 4, characterized in that, The air chamber pressure function of the buffer is: ； Wherein, P0 is the initial filling pressure parameter, V0 is the initial volume parameter of the air cavity, S is the stroke parameter, A2 is the outer diameter area parameter of the piston rod, and n is the air adiabatic index; where S=Z M -Z m , , v M v is the velocity parameter of the mass moving at the top of the outer cylinder. m The velocity parameter of the mass at the bottom of the piston rod is t, and the preset time parameter is t. The damping force function of the pressure difference between the main oil chamber and the air chamber of the buffer is: ； Where ρ is the oil density parameter, A3 is the piston rod inner diameter area parameter, and C dp Here, f is the flow coefficient of the main oil orifice during the positive stroke, f is the area parameter of the main oil orifice, and C is the flow coefficient of the main oil orifice during the positive stroke. dn Let v be the flow coefficient of the reverse stroke main oil orifice, and v be the compression speed parameter of the buffer; where v = v M -v m ; The damping force function of the pressure difference between the air chamber and the return oil chamber of the buffer is: ； Where A1 is the inner diameter area parameter of the outer cylinder, C drp f is the flow coefficient of the positive stroke return oil hole. rp C is the area parameter of the positive stroke return oil hole. drn f is the flow coefficient of the reverse stroke return oil hole. rn The area parameter of the reverse stroke return oil hole; The motion state load function of the buffer is: F s = F a + △P h-a + △P a-r ; Among them, F a = A2*(P) a -P atm ), P atm These are the preset atmospheric pressure parameters.

6. The landing gear landing load calculation method according to any one of claims 1-5, characterized in that, The step of substituting the motion state load function into the target landing relationship function for solution to obtain the maximum vertical load parameter of the buffer includes: Substitute the motion state load function into the target landing relationship function to obtain the substituted function, and simplify the substituted function to obtain the simplified function. The simplified function is transformed by ordinary differential equation to obtain the transformed function, and the transformed function is solved to obtain the numerical solution of the motion velocity parameters of the lower mass of the piston rod. Based on the numerical solution, the time-displacement curve of the lower mass of the piston rod is determined, and based on the preset tire stiffness parameters of the buffer, the time-tire load curve of the lower mass of the piston rod is determined, so as to determine the maximum vertical load parameter of the buffer through the time-tire load curve. The simplified function is: ； K is the preset tire stiffness parameter of the buffer; The deformed function is: ； The time-tire load curve of the lower mass of the piston rod can be determined by the following formula: 。 7. The landing gear landing load calculation method according to claim 5, characterized in that, The initial filling pressure parameter of the buffer was determined in the following manner: Based on the preset statically determinate air chamber pressure function, statically determinate main oil chamber pressure function, and statically determinate return oil chamber pressure function of the buffer, and combined with the outer cylinder inner diameter area parameter, piston rod outer diameter area parameter, piston rod inner diameter area parameter and atmospheric pressure parameter of the buffer, the statically determinate state load function of the buffer is constructed. Determine the instantaneous landing correlation between the statically determinate air chamber pressure function, the statically determinate main oil chamber pressure function, the statically determinate return oil chamber pressure function, and the initial filling pressure parameter of the buffer; and calculate the initial filling pressure parameter of the buffer based on the instantaneous landing correlation and the statically determinate state load function. The statically determinate load function of the buffer is: F' s = P' a *(A1-A3)+ P h *A3- P r *(A1-A2)- P atm *A2; P' a Let P be the pressure function of the statically determinate air chamber. h Let P be the pressure function of the statically determinate main oil chamber. r The pressure function of the statically determinate return oil chamber; The landing instant correlation is: P' a = P h = P r = P0.

8. A landing gear landing load calculation device, characterized in that, The device includes: A simplification module is used to perform a two-mass simplification on the landing gear buffer to obtain the upper mass of the outer cylinder and the lower mass of the piston rod of the buffer; The construction module is used to construct the target landing relationship function of the buffer based on the upper mass of the outer cylinder and the lower mass of the piston rod; and to construct the motion state load function of the buffer. The solution module is used to substitute the motion state load function into the target landing relationship function for solution to obtain the maximum vertical load parameter of the buffer; The determination module is used to determine other load parameters of the buffer based on the maximum vertical load parameter, and to determine the landing load parameters of the landing gear based on the maximum vertical load parameter and the other load parameters.

9. A landing gear landing load calculation device, characterized in that, The device includes: Memory containing executable program code; A processor coupled to the memory; The processor calls the executable program code stored in the memory to execute the landing gear landing load calculation method as described in any one of claims 1-7.

10. A computer storage medium, characterized in that, The computer storage medium stores computer instructions, which, when invoked, are used to execute the landing gear landing load calculation method as described in any one of claims 1-7.

Images