A method for modeling an oil-gas buffer based on MATLAB

Abstract

This invention provides a method for modeling an oil-gas buffer based on MATLAB. The method includes: determining the internal forces of the oil-gas buffer to be simulated; creating a multibody dynamics model of the oil-gas buffer based on MATLAB; and determining the input parameters of the multibody dynamics model by preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, combined with design parameters. This invention achieves accurate modeling of the oil-gas buffer using a relatively simple method, avoiding data interaction between the Adams and MATLAB software platforms, and eliminating the need to handle the interface development between the two different software platforms.

Description

Technical Field

[0001] This invention relates to the field of virtual simulation modeling, and in particular to a method for modeling oil-gas buffers based on MATLAB. Background Technology

[0002] The landing shield is a critical component in the rocket landing process. The extent to which it reduces the landing load directly affects whether the rocket can land stably, and further affects whether the rocket can be recovered. In the early stages of rocket development, ground drop tests are difficult and costly, requiring the use of simulation methods to analyze the rocket landing process, especially to perform detailed modeling of the landing shields.

[0003] Existing technologies typically use Adams multibody dynamics simulation to model outrigger buffers. However, this method also requires the use of MATLAB for control scheme construction and post-processing. The modeling process requires the use of both Adams and MATLAB software platforms, as well as data interaction between the two platforms. Additionally, it is necessary to address the issue of interface development between different software platforms. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for modeling oil-gas buffers based on MATLAB. This method solves the problems of existing technologies that require the use of two software platforms, Adams and MATLAB, for modeling, and that the modeling process requires data interaction between the two software platforms, as well as the need to handle the interface development between different software platforms.

[0005] This invention provides a method for modeling oil-gas buffers based on MATLAB, the method comprising:

[0006] Determine the internal forces of the oil-gas buffer to be simulated;

[0007] A multibody dynamics model of the oil-gas buffer was created using MATLAB.

[0008] By preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, the input parameters of the multibody dynamics model are determined in conjunction with the design parameters.

[0009] Optionally, determining the internal forces of the oil-gas buffer to be simulated includes simplifying the internal forces of the oil-gas buffer during operation into independent nonlinear spring forces, nonlinear damping forces, and structural restraint forces.

[0010] Optionally, the creation of the multibody dynamics model of the oil-gas buffer based on MATLAB includes:

[0011] We selected the following models for a hydroponic buffer: structural model, prism hinge model, dead zone model, nonlinear spring model, nonlinear damping model, reference point model, and translational multibody interface model.

[0012] The nonlinear spring force is simulated by the nonlinear spring model, the nonlinear damping force is simulated by the nonlinear damping model, the structural limiting force is simulated by the dead zone model, the prism hinge model is connected to the oil-gas buffer structure model and the translational multibody interface model respectively, the dead zone model, the nonlinear spring model, the nonlinear damping model and the translational multibody interface model are interconnected, and the dead zone model, the nonlinear spring model, the nonlinear damping model and the translational multibody interface model are connected to the reference point model.

[0013] Optionally, the oil-gas type buffer structure model includes a piston and a sleeve, and there is only mutual translation between the piston and the sleeve.

[0014] Optionally, the spring force versus compression stroke curve and the damping force versus compression speed curve are obtained by performing static pressure curve tests and damping performance tests on the actual oil-gas buffer.

[0015] Optionally, the step of preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, and determining the input parameters of the multibody dynamics model in conjunction with design parameters, includes:

[0016] Sort all coordinate points of the spring force versus compression stroke curve and the damping force versus compression speed curve from smallest to largest according to the magnitude of the horizontal axis.

[0017] Based on the sorted spring force and compression stroke curves, the initial compression stroke, spring force vector, and compression stroke vector of the nonlinear spring model are determined.

[0018] Based on the sorted spring force and compression stroke curves and the design parameters, the structural constraint stiffness, upper structural constraint boundary, and lower structural constraint boundary of the dead zone model are determined.

[0019] Based on the sorted damping force and compression velocity curves, the damping force vector and compression velocity vector of the nonlinear damping model are determined.

[0020] Optionally, determining the initial compression stroke, spring force vector, and compression stroke vector of the nonlinear spring model based on the sorted spring force versus compression stroke curve and damping force versus compression velocity curve includes:

[0021] The initial compression stroke is obtained by calculating the distance from the intersection of the line connecting the first and second coordinate points in the sorted spring force and compression stroke curve with the horizontal axis to the horizontal coordinate of the second coordinate point.

[0022] The sorted spring force and compression stroke curves are shifted to the right by the length of the initial compression stroke to obtain the shifted spring force and compression stroke curves.

[0023] The new coordinate origin is connected to the translated spring force and compression stroke curve to obtain the final spring force and compression stroke curve;

[0024] The ordinates of all coordinate points on the final spring force and compression stroke curve are sequentially assigned to the spring force vector, and the abscissas of all coordinate points on the final spring force and compression stroke curve are sequentially assigned to the compression stroke vector.

[0025] Optionally, determining the structural constraint stiffness, upper structural constraint boundary, and lower structural constraint boundary of the dead zone model based on the sorted spring force and compression stroke curves and the design parameters includes:

[0026] The design parameters include the structural constraint stiffness and the structural constraint upper boundary;

[0027] The lower boundary of the structural constraint is the ratio of the ordinate of the first coordinate point in the sorted spring force and compression stroke curve to the structural constraint stiffness.

[0028] Optionally, determining the damping force vector and compression velocity vector of the nonlinear damping model based on the sorted damping force and compression velocity curves includes:

[0029] The ordinates of all coordinate points on the sorted damping force and compression velocity curves are sequentially assigned to the damping force vector, and the abscissas of all coordinate points on the sorted damping force and compression velocity curves are sequentially assigned to the compression velocity vector.

[0030] Optionally, it also includes conducting a drop test by combining the multibody dynamics model, counterweight model, tooling model and ground model of the oil-gas buffer.

[0031] This invention provides a method for modeling an oil-gas buffer based on MATLAB. The method includes: determining the internal forces of the oil-gas buffer to be simulated; creating a multibody dynamics model of the oil-gas buffer based on MATLAB; and determining the input parameters of the multibody dynamics model by preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, combined with design parameters. Compared with existing technologies, this invention provides a simpler modeling method, using only the MATLAB software platform to accurately model the oil-gas buffer, avoiding data interaction between the Adams and MATLAB software platforms, and eliminating the need to handle the interface writing issues between the two different software platforms. The preprocessing, ensuring that the spring force versus compression stroke curve and the damping force versus compression velocity curve meet the model setting requirements in MATLAB / Simulink, is a crucial step in realizing this invention. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a method for modeling an oil-gas buffer based on MATLAB, provided in an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram illustrating the working principle of the oil-gas buffer provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of the oil-gas buffer provided in an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of a prism hinge model provided in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the dead zone model provided in an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of the dead zone model principle provided in an embodiment of the present invention;

[0038] Figure 7 A schematic diagram of a nonlinear spring model provided in an embodiment of the present invention;

[0039] Figure 8 A schematic diagram of the nonlinear damping model provided in an embodiment of the present invention;

[0040] Figure 9 A schematic diagram of a reference point model provided in an embodiment of the present invention;

[0041] Figure 10 This is a schematic diagram of a translational multibody interface model provided in an embodiment of the present invention;

[0042] Figure 11This is a schematic diagram illustrating the connection methods between various models provided in the embodiments of the present invention;

[0043] Figure 12 This is a schematic diagram of the spring force versus compression stroke curve of the oil-gas type shock absorber provided in an embodiment of the present invention;

[0044] Figure 13 A schematic diagram of the damping force versus compression speed curve of the oil-gas buffer provided in this embodiment of the invention;

[0045] Figure 14 This is a schematic diagram of the drop test specimen model provided in an embodiment of the present invention;

[0046] Figure 15 This is a schematic diagram of the virtual drop test process provided in an embodiment of the present invention;

[0047] Wherein: a is a schematic diagram of free fall in the air, b is a schematic diagram of ground collision impact, c is a schematic diagram of compression of oil-gas buffer, and d is a schematic diagram of rebound of oil-gas buffer.

[0048] Figure 16 This is a schematic diagram comparing virtual test loads during drop earthquakes, provided in an embodiment of the present invention. Detailed Implementation

[0049] To address the challenges of existing technologies that require the use of both Adams and MATLAB software platforms for modeling, necessitating data interaction between these two platforms and handling interface development between them, this invention provides a method for modeling oil-gas buffers based on MATLAB.

[0050] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] This embodiment provides a method for modeling oil-gas buffers based on MATLAB, such as... Figure 1 As shown, the method includes:

[0052] S1: Determine the internal forces of the oil-gas buffer to be simulated;

[0053] To better simulate a hydropneumatic buffer, its mechanical characteristics must first be analyzed. The physical mechanism of a hydropneumatic buffer is complex, such as... Figure 2 As shown, the forces consist of the air spring force 3, the oil damping force 4, the frictional force 6 between the sleeve 2 and the piston 1, and the structural restraint force 5. The air spring force includes the initial preload. Because the frictional force between the sleeve and the piston is affected by oil lubrication, it is relatively small compared to the air spring force and the oil damping force, and can be ignored. The magnitude of the air spring force is related to the initial preload pressure, piston area, initial volume, and design stroke, and its expression is as follows:

[0054]

[0055] In the formula, F s Let P0 be the initial air spring force, A0 be the piston area, V0 be the initial volume, and X be the initial air spring force. s For the compression stroke, γ represents the gas polytropic exponent. During rocket landing, the initial preload is overcome first, followed by a gradual decrease in internal cavity volume and a gradual increase in air pressure; the overall process is characterized as nonlinear.

[0056] The oil damping force is related to the oil density, the area of ​​the oil chamber orifice, and the piston speed of the oil-gas damper, and its expression is as follows:

[0057]

[0058] In the formula, F c Where ρ is the oil damping force, ρ is the oil density, and D is the oil density. c Let A be the oil orifice flow coefficient. c The area of ​​the oil chamber orifice is... This refers to the compression speed.

[0059] The structural restraint force is related to the structural restraint stiffness of the hydropneumatic buffer and has no damping. The characteristic of the structural restraint force decreasing from its present state to its absence can be described by the following piecewise function:

[0060]

[0061] In the formula, F j For structural confinement force, k j Here, x is the structural limiting stiffness (also known as contact stiffness or structural limiting elastic constant), x0 is the position where the piston just contacts the sleeve, and x is the distance of the piston relative to the position where it just contacts the sleeve. max The maximum compression stroke is designed for the oil-gas type shock absorber.

[0062] When the hydropneumatic buffer is not compressed, the initial preload and the structural restraining force between the piston and the sleeve are in equilibrium. The buffer begins to compress only when the external force acting on it exceeds the initial preload, at which point the structural restraining force disappears. The initial preload is related to the initial charge pressure and the piston area, and its expression is as follows:

[0063] F i =P0A0=k j x0

[0064] In the formula, F i This is the initial preload.

[0065] Based on the mechanical characteristics of the above-mentioned oil-gas buffer, the internal forces of the oil-gas buffer during operation can be simplified into independent nonlinear spring force, nonlinear damping force and structural restraint force, wherein the nonlinear spring force includes the initial preload.

[0066] S2: Creating a multibody dynamics model of an oil-gas buffer based on MATLAB;

[0067] By selecting a model in Matlab / Simulink to simulate the simplified internal forces described above, accurate modeling of the oil-gas buffer can be achieved. The multibody dynamics model of the oil-gas buffer includes:

[0068] The oil-gas buffer structure model can be selected from the Simscape / Multibody / Body Elements module. It can be done by selecting a simple model or importing an actual structural model file. This example uses the method of importing an actual structural model file to select the oil-gas buffer structure model. This example ignores the complex internal structure of the oil-gas buffer. Figure 3 As shown, the structure of the oil-gas buffer is simplified into two parts: piston 1 and sleeve 2. There is only mutual translation between the piston and the sleeve.

[0069] Prismatic Joint Model: Select the Prismatic Joint model in the Simscape / Multibody / Joints module, such as... Figure 4 As shown, this is used to simulate the mutual translational motion between the piston and the sleeve.

[0070] Dead Zone Model: Select the Translational Hard Stop model in the Simscape / Foundation Library / Mechanical / Translational Elements module, such as... Figure 5 As shown, this model is used to simulate structural restraint forces. The principle of this model is as follows: Figure 6 As shown, the slider acts like a piston. When it reaches zero on the x-axis, it is in its initial position. When the slider moves to the left beyond the boundary g... n When subjected to stiffness K n The structural restraint force caused it to move to the right beyond the boundary g. p When subjected to stiffness K p Structural restraint force, upper and lower stiffness K of structural restraint force n or K p Take k j The value of the damping parameter D is determined because there is no damping in the structural constraint force. n and D pSet to zero. This model can effectively simulate the situation where, after initial pressurization, the piston extending outward in an oil-gas damper is restricted by the internal structure of the sleeve without external load, and the situation where it is restricted by the sleeve structure after exceeding the design compression stroke, thus acting as a "dead zone".

[0071] Nonlinear Spring Model: Select the Nonlinear Translational Spring model in the Simscape / Driveline / Couplings&Drives / Springs&Dampers module, such as... Figure 7 As shown, it is used to simulate nonlinear spring force.

[0072] Nonlinear Damping Model: Select the Nonlinear Translational Damper model in the Simscape / Driveline / Couplings&Drives / Springs&Dampers module, such as... Figure 8 As shown, it is used to simulate nonlinear damping force.

[0073] Reference point model: Select the Mechanical Translational Reference model in the Simscape / Physical Modeling / Mechanical Models / Translational Elements module, such as... Figure 9 As shown, a reference point is defined. The displacement and velocity of the piston relative to the sleeve are based on this reference point, which is provided by the prism hinge model.

[0074] Translational Multibody Interface Model: Select the Translational Multibody Interface model in the Simscape / Foundation Library / Mechanical / MultibodyInterfaces module, such as... Figure 10 As shown, this is used to simulate the interaction interface between the prism hinge model and the nonlinear spring model, nonlinear damping model, and dead zone model.

[0075] The connection methods between the models are as follows Figure 11As shown, port B of the prism hinge model is connected to the sleeve of the oil-gas buffer structure model, port F of the prism hinge model is connected to the piston of the oil-gas buffer structure model, port v of the prism hinge model is connected to port v of the translational multibody interface model, port f of the prism hinge model is connected to port f of the translational multibody interface model, ports R of the dead zone model, nonlinear spring model, nonlinear damping model, and translational multibody interface model are interconnected and connected to the reference point model, and ports C of the dead zone model, nonlinear spring model, nonlinear damping model, and translational multibody interface model are interconnected.

[0076] S3: By preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, the input parameters of the multibody dynamics model are determined in combination with the design parameters.

[0077] To determine the input parameters for the nonlinear spring, nonlinear damping, and dead-zone models, static pressure curve tests and damping performance tests need to be performed on the manufactured oil-gas buffer to obtain the raw, unprocessed spring force versus compression stroke curves and damping force versus compression velocity curves. These raw, unprocessed curves may not be arranged in ascending order of their horizontal axis values; therefore, they need to be sorted in ascending order according to their horizontal axis values. In this embodiment, the sorted spring force versus compression stroke curves and damping force versus compression velocity curves are as follows: Figure 12 and Figure 13 As shown.

[0078] When simulating nonlinear spring forces, the nonlinear spring model can be given as a first-order polynomial, or it can be imported through linear interpolation based on a given spring force vector and corresponding compression stroke vector. An initial compression stroke can be specified, and it must be ensured that when an element in the compression stroke vector is zero, the corresponding element in the spring force vector is also zero. This embodiment uses the imported vector method. Based on the expression for air spring force and... Figure 12 As is known, when the compression stroke is zero, the air spring force is not actually zero. The air spring force present at this time is the initial preload. Therefore, the sorted spring force and compression stroke curves need to be processed as follows:

[0079] To meet the requirements of the nonlinear spring model, the compression stroke under the initial preload is defined as no longer zero, but rather corresponds to an initial compression stroke. The initial compression stroke is defined as the distance from the intersection of the line connecting the first and second coordinate points on the sorted spring force and compression stroke curve with the horizontal axis to the horizontal coordinate of the second coordinate point. During the compression process of the oil-gas buffer, the compression stroke is always greater than the initial compression stroke. According to... Figure 12The spring force versus compression stroke curves shown in the figure indicate that the initial compression stroke is 0.2848 m.

[0080] The sorted spring force and compression stroke curves are shifted to the right by the length of the initial compression stroke to obtain the shifted spring force and compression stroke curves.

[0081] The new coordinate origin is connected to the translated spring force and compression stroke curve to obtain the final spring force and compression stroke curve;

[0082] Assign the ordinates of all points on the final spring force and compression stroke curve to the spring force vector, and assign the abscissas of all points on the final spring force and compression stroke curve to the compression stroke vector.

[0083] When simulating nonlinear damping forces, the nonlinear damping model can be given as a first-order polynomial, or it can be imported through linear interpolation based on a given damping force vector and corresponding compression velocity vector. Simultaneously, it must satisfy the condition that when an element in the compression velocity vector is zero, the corresponding element in the damping force vector is also zero. This embodiment uses the vector import method. Based on the expression for oil damping force and... Figure 13 As is known, when the compression speed is zero, the oil damping force is also zero. Therefore, no processing is required on the sorted damping and compression speed curves. The vertical coordinates of all coordinate points on the sorted damping force and compression speed curves can be directly assigned to the damping force vector, and the horizontal coordinates of all coordinate points on the sorted damping force and compression speed curves can be assigned to the compression speed vector.

[0084] Structural confinement forces restrict motion within the structural boundaries; therefore, the structural confinement stiffness needs to be set to a large value to limit structural compression under initial preload, typically greater than or equal to 10. 8 N / m; the upper boundary of the structural limit is the maximum compression stroke designed for the oil-gas buffer; the lower boundary of the structural limit is the position where the piston just contacts the sleeve, obtained by calculating the ratio of the ordinate of the first coordinate point in the sorted spring force and compression stroke curve to the structural limit stiffness. In this embodiment, the structural limit stiffness is taken as 10. 8 N / m, the upper boundary of the structural constraint is set at 0.3m, according to Figure 12 The spring force versus compression stroke curves, after being sorted as shown, yield a calculated lower boundary for structural constraint of 3.41 × 10⁻⁶. -4 m.

[0085] S4: Conduct virtual drop test by combining the multibody dynamics model, counterweight model, tooling model and ground model of the oil-gas buffer.

[0086] The drop test specimen model is composed of a multibody dynamics model of an oil-gas buffer, a counterweight model 7, a tooling model 8, and a ground model 9. Its structure is as follows: Figure 14 As shown in the figure, the multibody dynamics model of the hydropneumatic buffer is not fully displayed; only the structural model of the hydropneumatic buffer, namely piston 1 and sleeve 2, is shown. A virtual drop test was conducted based on the drop test specimen model. The virtual drop test process is as follows: Figure 15 As shown, the experiment includes four processes: free fall from the air, ground impact, compression of the hydropneumatic buffer, and rebound of the hydropneumatic buffer. During the test, the multibody dynamics model of the hydropneumatic buffer was subjected to free fall from the air, and the accuracy of the buffer modeling was verified through the collision and impact between the tooling model and the ground model. In this embodiment, the counterweight model is set to 30t, and simulation analysis yields the following results: Figure 16 The diagram shows a comparison of loads between the virtual drop test and the theoretical model. Figure 16 It can be seen that the results of the drop-earthquake virtual test are in good agreement with the theoretical model analysis, which verifies the accuracy of the oil-gas buffer model.

[0087] This invention provides a method for modeling an oleo-gas buffer based on MATLAB. The method includes: determining the internal forces of the oleo-gas buffer to be simulated; creating a multibody dynamics model of the oleo-gas buffer based on MATLAB; and determining the input parameters of the multibody dynamics model by preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, combined with design parameters. Compared with existing technologies, this invention provides a simpler modeling method, using only the MATLAB software platform to accurately model the oleo-gas buffer, avoiding data interaction between the Adams and MATLAB software platforms, and eliminating the need to handle the interface writing issues between the two different software platforms. The preprocessing, ensuring that the spring force versus compression stroke curve and the damping force versus compression velocity curve meet the model setting requirements in MATLAB / Simulink, is a crucial step in realizing this invention. Simultaneously, drop-and-vibration virtual tests were conducted based on MATLAB, verifying the accuracy of the oleo-gas buffer modeling. Furthermore, MATLAB's advantages in programming languages ​​and data processing also support multivariate parameter modeling and multivariate optimization target analysis of the oleo-gas buffer, further providing support for the drop-and-vibration tests of recovered rockets and the performance design of outrigger oleo-gas buffers.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for modeling an oil-gas damper based on MATLAB, characterized in that, The method includes: Determine the internal forces of the oil-gas type buffer to be simulated, including nonlinear spring force, nonlinear damping force, and structural restraint force; A multibody dynamics model of the oil-gas buffer was created using MATLAB. This model includes a structural model of the oil-gas buffer, a prism hinge model, a dead zone model, a nonlinear spring model, a nonlinear damping model, a reference point model, and a translational multibody interface model. The nonlinear spring model simulates the nonlinear spring force, the nonlinear damping model simulates the nonlinear damping force, and the dead zone model simulates the structural restraint force. The prism hinge model is connected to both the structural model of the oil-gas buffer and the translational multibody interface model. The dead zone model, the nonlinear spring model, the nonlinear damping model, and the translational multibody interface model are interconnected. Finally, the dead zone model, the nonlinear spring model, the nonlinear damping model, and the translational multibody interface model are connected to the reference point model. By preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, the input parameters of the multibody dynamics model are determined in conjunction with the design parameters. The process of preprocessing the spring force versus compression stroke curve and the damping force versus compression velocity curve, and then determining the input parameters of the multibody dynamics model in conjunction with design parameters, includes: Sort all coordinate points of the spring force versus compression stroke curve and the damping force versus compression speed curve from smallest to largest according to the magnitude of the horizontal axis. Based on the sorted spring force and compression stroke curves, the initial compression stroke, spring force vector, and compression stroke vector of the nonlinear spring model are determined. Based on the sorted spring force and compression stroke curves and the design parameters, the structural constraint stiffness, upper structural constraint boundary, and lower structural constraint boundary of the dead zone model are determined. Based on the sorted damping force and compression velocity curves, the damping force vector and compression velocity vector of the nonlinear damping model are determined.

2. The method of claim 1, wherein, The oil-gas type buffer structure model includes a piston and a sleeve, and there is only mutual translation between the piston and the sleeve.

3. The method of claim 1, wherein, The spring force versus compression stroke curve and the damping force versus compression speed curve were obtained by performing static pressure curve tests and damping performance tests on the actual oil-gas buffer.

4. The method of claim 1, wherein, The determination of the initial compression stroke, spring force vector, and compression stroke vector of the nonlinear spring model based on the sorted spring force and compression stroke curves includes: The initial compression stroke is obtained by calculating the distance from the intersection of the line connecting the first and second coordinate points in the sorted spring force and compression stroke curve with the horizontal axis to the horizontal coordinate of the second coordinate point. The sorted spring force and compression stroke curves are shifted to the right by the length of the initial compression stroke to obtain the shifted spring force and compression stroke curves. The new coordinate origin is connected to the translated spring force and compression stroke curve to obtain the final spring force and compression stroke curve; The ordinates of all coordinate points on the final spring force and compression stroke curve are sequentially assigned to the spring force vector, and the abscissas of all coordinate points on the final spring force and compression stroke curve are sequentially assigned to the compression stroke vector.

5. The method of claim 1, wherein, The determination of the structural constraint stiffness, upper structural constraint boundary, and lower structural constraint boundary of the dead zone model based on the sorted spring force and compression stroke curves and the design parameters includes: The design parameters include the structural constraint stiffness and the structural constraint upper boundary; The lower boundary of the structural constraint is the ratio of the ordinate of the first coordinate point in the sorted spring force and compression stroke curve to the structural constraint stiffness.

6. The method of claim 1, wherein, The determination of the damping force vector and compression velocity vector of the nonlinear damping model based on the sorted damping force and compression velocity curves includes: The ordinates of all coordinate points on the sorted damping force and compression velocity curves are sequentially assigned to the damping force vector, and the abscissas of all coordinate points on the sorted damping force and compression velocity curves are sequentially assigned to the compression velocity vector.

7. The method of any one of claims 1-6, wherein, It also includes conducting virtual drop tests by combining the multibody dynamics model, counterweight model, tooling model and ground model of the oil-gas buffer.

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