Primary and secondary separation parametric modeling method for carrier rocket

Abstract

The invention discloses a parametric modeling method for first-stage and second-stage separation of a carrier rocket. The method comprises the following steps: 1, carrying out structure and mass center position parameterized carrier rocket first and second sublevel rigid body modeling; 2, carrying out carrier rocket acting force modeling based on parameterization of the acting position and the acting direction; step 3, constructing a constraint device model between the first and second sublevel rigid bodies; 4, on the basis of the rigid body model, the acting force model and the restraint device model, building blocks and connecting lines are adopted, and a parameterized model of the carrier rocket first-stage and second-stage separation system is rapidly built; and 5, performing simulation verification on the parameterized model of the primary and secondary separation system by adopting a comparison verification mode. Therefore, the parameterized modeling method is based on the Modelica causal modeling language, rapid numerical simulation can be performed on the first-stage and second-stage separation process of the carrier rocket, the influence of parameters on first-stage and second-stage separation response is evaluated, the flexibility and expansibility of the model are improved, the research and development period of the carrier rocket is shortened, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of aerospace science and technology, and in particular to a parameterized modeling method for primary and secondary separation of a launch vehicle based on the Modelica unified modeling language. Background Art

[0002] A launch vehicle is a space transportation vehicle composed of multiple stages. Its purpose is to deliver payloads such as artificial satellites, manned spacecraft, space stations, and space probes into a predetermined orbit. In order to reduce negative mass, improve carrying capacity, and complete specific tasks, after each stage of the launch vehicle is used, the discarded parts need to be separated by a reliable separation system. The separation system must ensure that the separation bodies are effectively separated and the separation gap is increased to prevent collisions that affect the payload attitude and, in turn, the launch mission. There are many examples of launch failures in the history of space launches due to improper separation of the first and second stages.

[0003] In addition, the separation process of the first and second stages of the launch vehicle needs to consider the influence of multiple parameter deviations, such as mass characteristic deviations, initial condition deviations, and dynamic characteristic deviations. Such numerous deviations will make the two-body separation process prone to contact and collision between the second-stage engine and the first-stage engine, or even failure to escape. Therefore, it is very important to establish a parametric model of the first-stage separation system of the launch vehicle.

[0004] The separation process of the first and second stages involves multiple disciplines such as structural dynamics, multi-body dynamics, attitude control, aerodynamics, etc., which are related to the layout and shape selection of the launch vehicle, parameter design, etc., and it is necessary to combine multiple disciplines to conduct multi-physics field coupling simulation. It should be understood that the Modelica language is a language specially designed for unified modeling and simulation in multiple fields, and has unique advantages in multi-physics field coupling simulation. Because the Modelica language has the characteristics of object-oriented, equation-based, model reusable and hierarchical structure, it can effectively realize the modeling of the first and second separation system of the launch vehicle. Therefore, there is an urgent need for a solution that can construct a parametric model of the first and second separation system of the launch vehicle based on the Modelica unified modeling language. Summary of the invention

[0005] The purpose of the present invention is to establish a primary-secondary separation model of a launch vehicle based on a parameterized modeling method of the Modelica causal modeling language, to perform rapid numerical simulation on the primary-secondary separation process of the launch vehicle, and to evaluate the influence of parameters on the primary-secondary separation response, thereby increasing the flexibility and scalability of the model, shortening the development cycle of the launch vehicle and reducing the cost.

[0006] The technical solution to achieve the purpose of the present invention is: a parameterized modeling method for the separation of the first and second stages of a launch vehicle, comprising the following steps:

[0007] According to the mass, moment of inertia, length and diameter parameters of the first and second stages, the structural parameterized model of the first and second stage rigid bodies of the launch vehicle is constructed;

[0008] The parameterized model of the center of mass position of the first and second sub-stages is established according to the parameters of the ideal center of mass position, the axial offset of the center of mass, the lateral displacement of the center of mass and the circumferential angle of the lateral displacement of the center of mass;

[0009] According to the distance from the engine thrust action point to the axis, the distance from the theoretical cusp point and the azimuth parameters, a parameterized model of the force position of the forward thrust, reverse thrust and after-effect thrust is established;

[0010] A parameterized model of the force direction is established based on the engine installation angle, nozzle outlet angle, deflection angle, and deflection circumferential angle parameters;

[0011] Construct a constraint device model between the first and second sub-level rigid bodies;

[0012] Use all the above models to build a parametric model of the launch vehicle's primary and secondary separation system;

[0013] The parameterized model of the launch vehicle's primary and secondary separation system is used to numerically simulate the launch vehicle's primary and secondary separation process, and the influence of model parameters on the primary and secondary separation response is evaluated.

[0014] Preferably, the acting forces include reverse thrust, after-effect thrust, and swaying force acting on the first sub-stage, and forward thrust acting on the second sub-stage, and the established model includes a forward thrust position parameterized sub-model, a reverse thrust position parameterized sub-model, an after-effect thrust position parameterized sub-model, a swaying force position parameterized sub-model, a forward thrust direction parameterized sub-model, a reverse thrust direction parameterized sub-model, an after-effect thrust direction parameterized sub-model, and a swaying force direction parameterized sub-model.

[0015] Preferably, the sloshing force position parameterized sub-model is established according to the distance of the liquid sloshing force reference point from the theoretical cusp point, the distance from the axis line, and the circumferential angle parameter of the positive rotation around the x-axis of the established reference coordinate system;

[0016] The sway force direction parameterized sub-model is obtained by rotating the sway force reference point to the sway force action position vector by 90° around the x-axis.

[0017] The origin of the reference coordinate system is located at the center point of the tail end of a sub-stage, the x-axis is the longitudinal axis of the rocket, pointing to the head of the rocket is positive, the y-axis is in the longitudinal symmetry plane of the rocket, and the z-axis, x-axis and y-axis form a right-handed coordinate system.

[0018] Preferably, the parameterized model of the primary and secondary separation system of the launch vehicle is formed by connecting the constructed structural parameterized model, forward thrust position parameterized sub-model, reverse thrust position parameterized sub-model, after-effect thrust position parameterized sub-model, sloshing force action position parameterized sub-model, forward thrust direction parameterized sub-model, reverse thrust direction parameterized sub-model, after-effect thrust direction parameterized sub-model, and sloshing force direction parameterized sub-model through a connector, wherein the connector includes flow variables and potential variables, and the sum of the flow variables is zero while the potential variables are equal.

[0019] Preferably, a mathematical model is established based on the physical principles, force balance equations and torque balance equations of a parameterized model of a launch vehicle's primary and secondary separation system; the model is constructed using the Modelica unified modeling language and the interface is defined; the interface is used to transmit force, displacement, torque and rotation angle.

[0020] Preferably, the constraint device model consists of a constraint device, a signal generator and a connector connected to the first and second sub-level rigid bodies. The constraint device is used to constrain the relative position, speed and posture of the first and second sub-level rigid bodies, and enables the constraint device to release the constraint when receiving a signal from the signal generator.

[0021] Preferably, after constructing the parameterized model of the primary and secondary separation system of the launch vehicle, a comparative verification method is used to perform simulation verification on the parameterized model of the primary and secondary separation system.

[0022] Preferably, the platforms for comparative verification include but are not limited to: Adams and Matlab.

[0023] A launch vehicle primary and secondary separation parameterized modeling system, comprising:

[0024] The model decomposition module decomposes the separation process of the launch vehicle into a structural parameterized model, a center of mass position parameterized model, a force position parameterized model, a force direction parameterized model, and a constraint device model;

[0025] A parameterized analysis module is used to determine the parameters of each model decomposed by the model decomposition module.

[0026] The model building module builds the structural parameterized model of the first and second stage rigid bodies of the launch vehicle according to the mass, moment of inertia, length and diameter parameters of the first and second stages; builds the parameterized model of the center of mass position of the first and second stages according to the ideal center of mass position, center of mass axial offset, center of mass lateral displacement and center of mass lateral displacement circumferential angle parameters; builds the parameterized model of the force position of the forward thrust, reverse thrust and after-effect thrust according to the distance from the engine thrust action point to the axis, the distance from the theoretical cusp and the azimuth parameters; builds the parameterized model of the force direction according to the engine installation angle, nozzle outlet angle, deflection angle and deflection circumferential angle parameters; builds the constraint device model between the first and second stage rigid bodies;

[0027] The model building module builds a parameterized model of the primary and secondary separation system of a launch vehicle by combining all the models built by the model building module; the parameterized model of the primary and secondary separation system of a launch vehicle is used to numerically simulate the primary and secondary separation process of the launch vehicle and evaluate the influence of model parameters on the primary and secondary separation response.

[0028] Preferably, the acting forces include reverse thrust, after-effect thrust, and sway force acting on the first sub-stage, and forward thrust acting on the second sub-stage, and the established model includes a forward thrust position parameterized sub-model, a reverse thrust position parameterized sub-model, an after-effect thrust position parameterized sub-model, a sway force position parameterized sub-model, a forward thrust direction parameterized sub-model, a reverse thrust direction parameterized sub-model, an after-effect thrust direction parameterized sub-model, and a sway force direction parameterized sub-model; the sway force position parameterized sub-model is established based on the distance from the theoretical tip of the liquid sway force reference point, the distance from the axis line, and the circumferential angle parameter of the positive rotation around the established reference coordinate system x-axis; the sway force direction parameterized sub-model is obtained by rotating the sway force reference point to the sway force action position vector by 90° around the x-axis; the origin of the reference coordinate system is located at the center point of the tail end of the first sub-stage, the x-axis is the longitudinal axis of the rocket, pointing to the head of the rocket is positive, the y-axis is in the longitudinal symmetry plane of the rocket, and the z-axis, x-axis, and y-axis form a right-handed coordinate system.

[0029] Therefore, compared with the prior art, the present invention can achieve the following beneficial effects:

[0030] 1) The present invention performs parametric modeling based on a causal modeling language. Different coordinate systems can correspond to different parts of the system or different physical phenomena, making the expression of the calculation equation more intuitive and concise, reducing ambiguity in coordinate system modeling, improving semantic consistency, and simplifying the expression of the model.

[0031] 2) Developed based on the Modelica language, the developed parameterized model can be clearly structured, reusable and extensible, greatly improving modeling efficiency;

[0032] 3) It can quickly simulate the separation process of the first and second stages of the launch vehicle, and evaluate the influence of parameters on the first and second stage separation response, increase the flexibility and scalability of the model, shorten the development cycle of the launch vehicle and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0034] Figure 1 It is a flow chart of the parameterized modeling method for the separation of the primary and secondary stages of a launch vehicle based on the Modelica unified modeling language of the present invention;

[0035] Figure 2 It is the primary and secondary separation theoretical model of the present invention;

[0036] Figure 3 It is the parameterized theoretical model of the first and second level centroid positions of the present invention;

[0037] Figure 4 is a parameterized theoretical model of the force position and direction of the present invention, wherein (a) is a parameterized theoretical model of the force position, and (b) is a parameterized theoretical model of the force direction;

[0038] Figure 5 It is a force parameterization model based on Modelica language of the present invention, wherein (a) is a forward thrust model, (b) is a reverse thrust model, (c) is a post-thrust model, and (d) is a sloshing force model;

[0039] Figure 6 It is a constraint device model based on Modelica language of the present invention;

[0040] Figure 7 It is a parameterized model of the primary and secondary separation system of a launch vehicle built based on the Modelica unified modeling language of the present invention;

[0041] Figure 8 1 is a schematic diagram of a curve of after-effect thrust in the model of the present invention;

[0042] Fig. 9 It is a comparison diagram of the X-direction displacement, velocity, acceleration, angular velocity, and angular acceleration curves of a sub-level in the model of the present invention and the Adams model;

[0043] Fig.10 It is a comparison diagram of the Y-direction displacement, velocity, acceleration, angular velocity, and angular acceleration curves of a sub-level in the model of the present invention and the Adams model. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] A parametric modeling method for the separation of the first and second stages of a launch vehicle based on the Modelica unified modeling language. The theoretical model is as follows: Figure 2 As shown, the following steps are included:

[0046] Step 1: Parameterized structure and center of mass position of the launch vehicle first and second stage rigid body modeling, specifically:

[0047] The first and second sub-stage rigid body structure parameterized sub-models include the mass, moment of inertia, length, and diameter parameters of the first and second sub-stages. These parameters are used as constant inputs to the system dynamics equations and the first and second sub-stage gap measurement equations. These equations describe the state changes, input-output relationships, and internal processes of the system, and are usually included in the solver of the simulation tool. Take the second sub-stage center of mass dynamics equation and the center of mass dynamics equation as an example:

[0048]

[0049] Among them, M2 is the mass of the second stage, I2 is the moment of inertia of the second stage, r2 and ω2 are the position and angular velocity of the center of mass of the second stage, F2 and T2 are the force and torque acting on the second stage, and ρ2 is the vector of the force to the center of mass.

[0050] The parameterized sub-models of the center of mass position of the first and second sub-stage rigid bodies include the ideal center of mass position, the axial offset of the center of mass, the lateral displacement of the center of mass, and the circumferential angle of the lateral displacement of the center of mass. The parameterized sub-models of the center of mass position of the first and second sub-stages are established according to the parameters of the ideal center of mass position, the axial offset of the center of mass, the lateral displacement of the center of mass, and the circumferential angle of the lateral displacement of the center of mass;

[0051] Take the second child as an example. Figure 3 As shown, the ideal center of mass position of the second stage is r 2_0 In the global coordinate system:

[0052] r 2_0 =(x 2_0 y 2_0 z 2_0 ) T (3)

[0053] The second-stage center of mass offset vector δ2 can be expressed as:

[0054] δ2=(δ x2 δ r2 cosθ2 δ r2 sinθ2) T (4)

[0055] Where δ x2 is the axial offset of the second stage mass center (positive along the positive x direction), δ r2 is the lateral displacement of the second sub-stage center of mass, θ2 is the circumferential angle of the lateral displacement of the second sub-stage center of mass (taking the y-axis as the starting point, and rotating in the positive direction around the x-axis is positive).

[0056] Then the actual position r2 of the second sub-stage center of mass is:

[0057] r2=r 2_0 +δ2 (5)

[0058] Step 2: Modeling the launch vehicle force with parameterized action position and action direction, specifically:

[0059] Step 2.1, force position parameterization sub-model:

[0060] like Figure 4 As shown in (a), the forward thrust acts on the second stage, the reverse thrust and the after-effect thrust act on the first stage, and the parameters that determine the positions of the three forces are the same (taking the i-th forward thrust rocket as an example), which is the distance δ from the axis. i , the distance from the theoretical cusp x i (positive along the positive x direction), azimuth angle θ i (Taking the y direction as the starting point, the positive rotation around the x-axis is positive).

[0061] Taking the i-th reverse thrust rocket as an example, its azimuth angle θ i for:

[0062]

[0063] Where θ0 is the azimuth of the first reverse thrust rocket, and n is the number of reverse thrust rockets. The force position P of the i-th reverse thrust rocket i The coordinates of a point can be expressed as:

[0064] r i =(x i δ i cosθ i δ i sinθ i ) T (7)

[0065] The action surface of the sloshing force is the cross section where the reference point O′ is located. The parameters that determine its action position P are the distance x from the reference point to the theoretical cusp, the distance δ from the axis, and the circumferential angle λ of the positive rotation around the x-axis. Its position r FS It can be expressed as:

[0066] r FS =(x δcosλ δsinλ) T (8)

[0067] Step 2.2, force direction parameterized sub-model:

[0068] like Figure 4 As shown in (b), the parameters that determine the direction of the forward thrust, reverse thrust, and after-effect thrust are the same, which are the installation angle Nozzle exit angle β i , the deflection angle γ i , deflection circumferential angle λ i It is assumed that the installation angle, nozzle exit angle and deflection angle of the ith positive thrust rocket all occur in the plane formed by the axis and the force application point.

[0069] To determine the direction of the positive thrust, first make sure that there is no circumferential angle λ i When positive thrust direction n Fi , and then use n Fi Around the nozzle outlet direction n Ni Rotation angle λ i , the direction of positive thrust can be obtained.

[0070] The normal direction of the plane formed by the axis and the force application point can be expressed by O i P i Rotate 90° around the x-axis to get:

[0071] n i =(0 -sinθ i cosθ i ) T (9)

[0072] Installation angle Nozzle exit angle β i , the deflection angle γ i The direction of n i Positive rotation is positive, as shown. There is no circumferential angle λ i When positive thrust direction n Fi Axial (1 0 0) T Around i Rotation Angle Get, the rotation matrix R Fi for:

[0073]

[0074] There is no circumferential angle λ i When positive thrust direction n Fi :

[0075] n Fi =R Fi (1 0 0) T (11)

[0076] Nozzle outlet direction n Ni Can be axial (100) T Around i Rotation Angle Get, the rotation matrix R Ni for:

[0077]

[0078] The axial direction n at the nozzle outlet can be calculated Ni :

[0079] n Ni =R Ni (1 0 0) T (13)

[0080] Next, Fi Around n Ni The forward rotation reverse thrust deflects the circumferential angle λ i , the final direction of the positive thrust can be obtained, and its rotation matrix R FN for:

[0081] R FN =I+sin(λ i )N Ni +(1-cos(λ i ))N i 2 (14)

[0082] Positive thrust final direction for:

[0083]

[0084] Direction of sloshing force n FS It can be obtained by rotating O′P 90° around the x-axis, that is:

[0085] n FS =(0 -sinλ cosλ) T (16)

[0086] The force parameterized model based on Modelica unified modeling language is obtained as follows Figure 5 shown.

[0087] Step 3: Construct a constraint device model between the first and second sub-level rigid bodies. The constraint device model consists of a constraint device, a signal generator, and a connector connected to the first and second sub-level rigid bodies. The constraint device is used to constrain the relative position, speed, and posture of the first and second sub-level rigid bodies, and the constraint device releases the constraint when receiving a signal from the signal generator. Specifically:

[0088] Before separation, there is no relative motion or rotation between the first and second sub-stages, and the constraint equation is described as:

[0089]

[0090] In the formula, r A and r B are the intersection positions of the axial direction of the first and second sub-stages and the separation surface, θ A and θ B They are the attitude angles of the first and second sub-levels respectively.

[0091] Find its first and second order derivatives with respect to time:

[0092]

[0093] Thus, the constraint device model based on Modelica unified modeling language is obtained, such as Figure 6 shown.

[0094] Step 4: Based on the above rigid body model, force model and constraint device model, a parametric model of the first and second stage separation system of the launch vehicle is quickly built based on the Modelica unified modeling language by building blocks and connecting lines. Figure 7 As shown. The constructed structural parameterized model, forward thrust position parameterized sub-model, reverse thrust position parameterized sub-model, after-effect thrust position parameterized sub-model, sloshing force position parameterized sub-model, forward thrust direction parameterized sub-model, reverse thrust direction parameterized sub-model, after-effect thrust direction parameterized sub-model, and sloshing force direction parameterized sub-model are connected through a connector to form a parameterized model of the first and second stage separation system of the launch vehicle, wherein the connector includes flow variables and potential variables, and the sum of the flow variables is zero while the potential variables are equal.

[0095] A mathematical model is established based on the physical principles, force balance equations and torque balance equations of the primary and secondary separation parameterized model of the launch vehicle; the model is constructed using the Modelica unified modeling language, and code development and interface definition are performed based on the standard library; wherein the interface is used to transmit force, displacement, torque and rotation angle.

[0096] Step 5: Use a comparative verification method to simulate and verify the primary and secondary separation system parameterized model. The comparative verification platform includes but is not limited to: Adams, Matlab, etc.

[0097] The present invention also provides a launch vehicle primary and secondary separation parameterized modeling system, comprising:

[0098] The model decomposition module decomposes the separation process of the launch vehicle into a structural parameterized model, a center of mass position parameterized model, a force position parameterized model, a force direction parameterized model, a sloshing force position parameterized model, and a constraint device model;

[0099] A parameterized analysis module is used to determine the parameters of each model decomposed by the model decomposition module.

[0100] The model building module constructs the structural parameterized model of the first and second stage rigid bodies of the launch vehicle according to the mass, moment of inertia, length and diameter parameters of the first and second stages; establishes the parameterized model of the center of mass position of the first and second stages according to the ideal center of mass position, center of mass axial offset, center of mass lateral displacement and center of mass lateral displacement circumferential angle parameters; establishes the force position parameterized model of the forward thrust, reverse thrust and after-effect thrust according to the distance of the engine thrust action point from the axis line, the distance from the theoretical cusp point and the azimuth angle parameters; establishes the parameterized model of the sloshing force action position according to the distance of the liquid sloshing force reference point from the theoretical cusp point, the distance from the axis line and the circumferential angle parameters of the forward rotation around the x-axis of the reference coordinate system; establishes the parameterized model of the force direction according to the engine installation angle, nozzle outlet angle, deflection angle and deflection circumferential angle parameters; and constructs the constraint device model between the first and second stage rigid bodies;

[0101] The origin of the reference coordinate system is located at the center point of the tail end of a sub-stage, the x-axis is the longitudinal axis of the rocket, pointing to the head of the rocket is positive, the y-axis is in the longitudinal symmetry plane of the rocket, and the z-axis, x-axis and y-axis form a right-handed coordinate system.

[0102] The model building module builds a parameterized model of the primary and secondary separation system of a launch vehicle by combining all the models built by the model building module; the parameterized model of the primary and secondary separation system of a launch vehicle is used to numerically simulate the primary and secondary separation process of the launch vehicle and evaluate the influence of model parameters on the primary and secondary separation response.

[0103] For the introduction of the system corresponding to the method, please refer to the description of the specific steps of the above method.

[0104] Example

[0105] In order to verify the effectiveness of the method of the present invention, the following simulation is performed and compared with the simulation results of the ADAMS model.

[0106] Fig. 9 and Fig.10 The displacement, velocity, acceleration, angular velocity, and angular acceleration time history curves of the first and second stages of the launch vehicle in the X and Y directions are given. It can be seen from the two figures that before the first and second stages separate, due to the reduction of the aftereffect thrust (see Figure 8), the axial acceleration of the first and second stages are both decreasing. After separation, the first stage is subjected to a large reverse thrust, and the axial acceleration increases sharply in the opposite direction, while the second stage loses the effect of the after-effect thrust and is only subjected to a small forward thrust, and the acceleration decreases. It can also be seen from the figure that the Modelica model and the Adams model are very consistent, indicating the correctness of the first and second stage separation parameterized model of the launch vehicle established by the present invention.

[0107] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

[0109] Some of the techniques not described in the present invention belong to the known techniques in the art.

Claims

1. A parameterized modeling method for the separation of the first and second stages of a launch vehicle, characterized in that: The following steps are involved: According to the mass, moment of inertia, length and diameter parameters of the first and second stages, the structural parameterized model of the first and second stage rigid bodies of the launch vehicle is constructed; The parameterized model of the center of mass position of the first and second sub-stages is established according to the parameters of the ideal center of mass position, the axial offset of the center of mass, the lateral displacement of the center of mass and the circumferential angle of the lateral displacement of the center of mass; According to the distance from the engine thrust action point to the axis, the distance from the theoretical cusp point and the azimuth parameters, a parameterized model of the force position of the forward thrust, reverse thrust and after-effect thrust is established; A parameterized model of the force direction is established based on the engine installation angle, nozzle outlet angle, deflection angle, and deflection circumferential angle parameters; Construct a constraint device model between the first and second sub-level rigid bodies; Use all the above models to build a parametric model of the launch vehicle's primary and secondary separation system; The parameterized model of the launch vehicle's primary and secondary separation system is used to numerically simulate the launch vehicle's primary and secondary separation process, and the influence of model parameters on the primary and secondary separation response is evaluated.

2. The method according to claim 1, characterized in that The acting forces include reverse thrust, after-effect thrust and swaying force acting on the first stage, and forward thrust acting on the second stage. The established models include forward thrust position parameterized sub-model, reverse thrust position parameterized sub-model, after-effect thrust position parameterized sub-model, swaying force position parameterized sub-model, forward thrust direction parameterized sub-model, reverse thrust direction parameterized sub-model, after-effect thrust direction parameterized sub-model and swaying force direction parameterized sub-model.

3. The method according to claim 2, characterized in that The sloshing force position parameterized sub-model is established according to the distance of the liquid sloshing force reference point from the theoretical cusp point, the distance from the axis line, and the circumferential angle parameter of the positive rotation around the established reference coordinate system x-axis; The sway force direction parameterized sub-model is obtained by rotating the sway force reference point to the sway force action position vector by 90° around the x-axis. The origin of the reference coordinate system is located at the center point of the tail end of a sub-stage, the x-axis is the longitudinal axis of the rocket, pointing to the head of the rocket is positive, the y-axis is in the longitudinal symmetry plane of the rocket, and the z-axis, x-axis and y-axis form a right-handed coordinate system.

4. The method according to claim 2, characterized in that: The parameterized model of the primary and secondary separation system of the launch vehicle is formed by connecting the constructed structural parameterized model, forward thrust position parameterized sub-model, reverse thrust position parameterized sub-model, after-effect thrust position parameterized sub-model, sloshing force action position parameterized sub-model, forward thrust direction parameterized sub-model, reverse thrust direction parameterized sub-model, after-effect thrust direction parameterized sub-model, and sloshing force direction parameterized sub-model through a connector, wherein the connector includes flow variables and potential variables, and the sum of the flow variables is zero while the potential variables are equal.

5. The method according to claim 4, characterized in that A mathematical model is established based on the physical principles, force balance equations and torque balance equations of the parametric model of the primary and secondary separation system of the launch vehicle. The model is constructed and the interface is defined using the Modelica unified modeling language. The interface is used to transmit force, displacement, torque and rotation angle.

6. The method according to claim 1, characterized in that The constraint device model consists of a constraint device, a signal generator and a connector connected to the first and second sub-level rigid bodies. The constraint device is used to constrain the relative position, speed and posture of the first and second sub-level rigid bodies, and enables the constraint device to release the constraint when receiving a signal from the signal generator.

7. The method according to claim 1, characterized in that After constructing a parameterized model of the primary and secondary separation system of a launch vehicle, a comparative verification method is used to perform simulation verification on the parameterized model of the primary and secondary separation system.

8. The method according to claim 7, characterized in that The platforms for comparative verification include but are not limited to: Adams and Matlab.

9. A parametric modeling system for the separation of the first and second stages of a launch vehicle, characterized in that: include: The model decomposition module decomposes the separation process of the launch vehicle into a structural parameterized model, a center of mass position parameterized model, a force position parameterized model, a force direction parameterized model, and a constraint device model; A parameterized analysis module is used to determine the parameters of each model decomposed by the model decomposition module. The model building module builds the structural parameterized model of the first and second stage rigid bodies of the launch vehicle according to the mass, moment of inertia, length and diameter parameters of the first and second stages; builds the parameterized model of the center of mass position of the first and second stages according to the ideal center of mass position, center of mass axial offset, center of mass lateral displacement and center of mass lateral displacement circumferential angle parameters; builds the parameterized model of the force position of the forward thrust, reverse thrust and after-effect thrust according to the distance from the engine thrust action point to the axis, the distance from the theoretical cusp and the azimuth parameters; builds the parameterized model of the force direction according to the engine installation angle, nozzle outlet angle, deflection angle and deflection circumferential angle parameters; builds the constraint device model between the first and second stage rigid bodies; The model building module builds a parameterized model of the primary and secondary separation system of a launch vehicle by combining all the models built by the model building module; the parameterized model of the primary and secondary separation system of a launch vehicle is used to numerically simulate the primary and secondary separation process of the launch vehicle and evaluate the influence of model parameters on the primary and secondary separation response.

10. The system according to claim 9, characterized in that: The acting forces include reverse thrust, after-effect thrust and swaying force acting on the first stage, and forward thrust acting on the second stage. The established models include forward thrust position parameterized sub-model, reverse thrust position parameterized sub-model, after-effect thrust position parameterized sub-model, swaying force position parameterized sub-model, forward thrust direction parameterized sub-model, reverse thrust direction parameterized sub-model, after-effect thrust direction parameterized sub-model and swaying force direction parameterized sub-model; the swaying force position parameterized sub-model is established according to the distance from the theoretical tip point to the liquid swaying force reference point, the distance from the axis line and the circumferential angle parameter of the positive rotation around the established reference coordinate system x-axis; the swaying force direction parameterized sub-model is obtained by rotating the swaying force reference point to the swaying force action position vector by 90° around the x-axis; the origin of the reference coordinate system is located at the center point of the tail end of the first stage, the x-axis is the longitudinal axis of the rocket, pointing to the head of the rocket is positive, the y-axis is in the longitudinal symmetry plane of the rocket, and the z-axis, x-axis and y-axis form a right-handed coordinate system.

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