Method for optimizing unfolding process of retractable landing mechanism

Abstract

The invention provides an unfolding process optimization design method of a retractable landing mechanism. The unfolding process optimization design method at least comprises the following steps: determining size parameters and quality characteristics of a main supporting leg and an auxiliary supporting leg in the retractable landing mechanism; determining parameters required by kinematics calculation of each component in the retractable landing mechanism; determining an unfolding control mode, design parameters and a load borne in the unfolding process of the retractable landing mechanism; determining a to-be-optimized parameter and a parameter range; based on the above steps, establishing a parameterized and modularized air pressure-mechanical structure joint kinetic model by means of system simulation software; an optimization algorithm, an optimization target and constraint conditions are determined, an optimization analysis process is established in system simulation software, and a process for extracting a calculation result is compiled; the air pressure-mechanical structure joint kinetic model is driven, the analysis process and the calculation result extraction process are optimized to run, the calculation result is extracted after batch processing calculation of the parameterized model, and whether the calculation result meets the constraint condition or not is judged by optimizing the convergence condition of the algorithm.

Description

Technical Field

[0001] This invention relates to the field of reusable space launch vehicle technology, and in particular to an optimization method for the deployment process of an adjustable and deployable landing mechanism. Background Technology

[0002] In the field of reusable launch vehicle technology, the deployable landing mechanism is a key functional component for achieving vertical recovery and reuse of the launch vehicle. Its working principle is as follows: During launch, the mechanism retracts and fits tightly against the rocket body surface to ensure aerodynamic shape; during recovery, it deploys and reliably locks via a drive mechanism, forming a stable landing support. The kinematic and dynamic characteristics of this deployment process are crucial; for example, the deployment speed directly affects the structural impact strength and locking reliability, while the deployment time affects the functional realization of the landing mechanism.

[0003] Currently, the design and analysis of this deployment process mainly rely on a combination of design experience, dynamic simulation, and numerical calculation. A typical design process is as follows: First, based on engineering experience, the configuration and dimensional parameters of the mechanism are initially set; then, its kinematic model and dynamic control equations are established; subsequently, numerical calculation software or a dedicated dynamic simulation platform are used to solve the equations; finally, the design scheme is adjusted and iterated based on the numerical results.

[0004] This traditional method has several inherent drawbacks: First, the quality of the initial design is highly dependent on personal experience, which can easily lead to the initial scheme deviating from the optimal solution, thus requiring a large number of iterations, resulting in a long design cycle and high costs. Second, the analysis process usually fails to fully consider the dynamic coupling effect between the pneumatic drive system and the mechanical structure, and lacks joint simulation, resulting in a deviation between the simulation accuracy and the actual physical process. Third, the method is difficult to systematically and quantitatively reveal the influence of various design parameters and their interactions on the deployment performance, thus failing to efficiently guide the global optimal combination of design parameters and restricting further improvement of the mechanism's performance.

[0005] Therefore, there is an urgent need to provide an optimized design method for the deployment process of a retractable landing mechanism, which can simultaneously consider the combined effects of the pneumatic drive system and the mechanical system, as well as the problem of low design efficiency. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes an optimization method for the deployment process of a retractable landing mechanism.

[0007] This invention provides an optimization method for the deployment process of a retractable landing mechanism, comprising at least the following steps:

[0008] Step 1: Determine the dimensional parameters and mass characteristics of the main and auxiliary outriggers in the retractable landing mechanism;

[0009] Step 2: Determine the parameters required for kinematic calculations of each component in the retractable landing mechanism;

[0010] Step 3: Determine the deployment control method, design parameters, and loads experienced by the deployable landing mechanism during deployment;

[0011] Step 4: Determine the parameters to be optimized and their ranges in the design parameters based on the design scheme;

[0012] Step 5: Based on Step 1, Step 2 and Step 3, establish a parameterized and modular barometric-mechanical joint dynamic model of the retractable landing mechanism using system simulation software;

[0013] Step 6: Determine the optimization algorithm, optimization objective, and constraints, and build the optimization analysis process and develop the process for extracting calculation results in the system simulation software;

[0014] Step 7: Run the combined dynamic model of the pneumatic-mechanical structure, the optimization analysis process, and the process of extracting calculation results. After batch calculation of the parameterized model, extract the calculation results and judge whether the calculation results meet the constraints by the convergence conditions of the optimization algorithm.

[0015] Step 8: If the calculation result does not meet the constraints, the optimization algorithm will be used to automatically optimize and adjust the parameters to be optimized, and the operation of Step 7 will be repeated until the calculation result meets the constraints and the optimization goal is achieved.

[0016] Furthermore, the dimensional parameters and mass characteristics of the main support leg and the auxiliary support leg in step one include at least: the number of stages of the multi-stage sleeve of the main support leg, the diameter, length, mass, center of mass position and moment of inertia of each stage sleeve; and the overall length, mass, center of mass position and moment of inertia of the auxiliary support leg.

[0017] Furthermore, the parameters required for the kinematic calculation of each component in step two include at least: the installation positions of the main outrigger and the auxiliary outrigger on the carrier, as well as the relative positions, kinematic pair positions, and kinematic pair types between the components of the main outrigger and the auxiliary outrigger.

[0018] Furthermore, in step three, the deployment control method adopts a pneumatic drive control method; the design parameters include the diameter of each stage cylinder and push rod between the multi-stage sleeves of the main outrigger, the stroke of each stage cylinder, the diameter and length of the air inlet and outlet of each stage cylinder, the timing of the control signals, the type of gas, the capacity and pressure of the gas cylinder, and the throttling orifice area of ​​the solenoid valve; the loads experienced during the deployment process include at least: the aerodynamic loads acting on the landing mechanism during the deployment process, the friction and damping forces between each kinematic pair, as well as the external air pressure, overload acceleration, and the attitude angle load parameters of the landing mechanism.

[0019] In any of the above embodiments, the retractable landing mechanism pneumatic-mechanical structure combined dynamics model in step five includes at least: a control module, a pneumatic system module, and a mechanical system module; the control module is used for the timing control of cylinder actions, as well as the acquisition of arrival time and arrival speed; the pneumatic system module receives signals from the control module to simulate the movement of the cylinder; the mechanical system module includes a main outrigger structure, a secondary outrigger structure and their components, as well as kinematic pairs and sensors; it is used to define the overall coordinate system, the magnitude and direction of the gravity field, and the spatial position, mass characteristics, and relative motion relationships of each mechanical component, and to simulate the overall deployment motion process of the landing mechanism and the extraction of required motion parameters; during the operation of the retractable landing mechanism pneumatic-mechanical structure combined dynamics model, the control module is used to drive the pneumatic system module to move, and drives the outrigger structure in the mechanical system module to open through the simulated cylinder, thereby simulating the overall deployment of the landing mechanism.

[0020] In one embodiment, the parameter to be optimized, the optimization algorithm, the constraints, and the optimization objective are all customized according to design requirements.

[0021] In one embodiment, the pneumatic system module includes: a gas cylinder, a solenoid valve, a gas pipeline, a primary cylinder, and a secondary cylinder; the gas cylinder is connected to the primary cylinder and the secondary cylinder respectively via the solenoid valve disposed on the gas pipeline; the control module controls the opening and closing of the solenoid valve; after the solenoid valve is opened, the gas in the gas cylinder fills the primary cylinder and the secondary cylinder, and after filling is completed, the control module controls the solenoid valve to close.

[0022] In one embodiment, the calculation results extracted in step six mainly include the speed and time of the landing mechanism's deployment into position; the speed of deployment into position refers to the speed of the end of the main outrigger away from the carrier relative to the ground when the main outrigger of the landing mechanism reaches its maximum deployment stroke; the time of deployment into position refers to the time required for the main outrigger of the landing mechanism to begin its deployment action and reach its deployment position.

[0023] In one embodiment, the moment of inertia is the moment of inertia of each component about its center of mass.

[0024] In one embodiment, the optimization algorithm is selected from, but is not limited to, a sequential quadratic programming algorithm and a genetic algorithm.

[0025] The present invention provides an optimized design method for the deployment process of a retractable landing mechanism, which has at least one of the following beneficial effects:

[0026] The present invention provides an optimized design method for the deployment process of a retractable landing mechanism. This method simplifies the mechanical and pneumatic drive structures in the landing mechanism and establishes a parameterized pneumatic-mechanical system joint dynamic model. The deployment process of the landing mechanism is calculated using system simulation software, which solves the problem that the existing technology cannot consider the combined effect of the pneumatic drive system and the mechanical system.

[0027] Second, the pneumatic-mechanical system joint dynamic model of this invention realizes the parameterization and modular construction of each component, and can add or remove components as needed, adjust control schemes and design parameters, thereby improving modeling efficiency.

[0028] Third, this invention can optimize and batch calculate the design parameters that need to be adjusted, and determine the optimal parameters that satisfy the constraints of the deployment process and the optimization objectives, which greatly improves the design efficiency of the landing mechanism and shortens the design iteration cycle of one to two months required by the traditional landing mechanism design method to two to three days.

[0029] Upon reading the detailed embodiments and examining the accompanying drawings, those skilled in the art will recognize additional features and advantages. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0031] Figure 1 This is a flowchart illustrating the operational steps of the optimized design method for the deployment process of the retractable landing mechanism according to an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the retractable landing mechanism according to an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the combined pneumatic-mechanical system of the retractable landing mechanism according to an embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram of the optimized design process of the deployment process of the retractable landing mechanism according to an embodiment of the present invention. Detailed Implementation

[0035] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and to exemplify the principles of the present invention, and are not configured to limit the present invention. In addition, the structural components in the drawings are not necessarily drawn to scale. For example, the dimensions of some structural components or regions in the drawings may be enlarged for other structural components or regions to aid in the understanding of the embodiments of the present invention.

[0036] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the embodiments of the present invention. In the description of the present invention, it should be noted that, unless otherwise stated, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0037] Furthermore, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure or component that includes a list of elements includes not only those elements but also other structural elements that are not expressly listed or inherent to the structure or component. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes the element.

[0038] Spatial relation terms such as "below," "under," "under," "low," "above," "on," and "high" are used for descriptive convenience to explain the positioning of one element relative to a second element, indicating that these terms are intended to cover different orientations of the device, in addition to those different from those shown in the figure. Furthermore, phrases such as "one element on / below another element" can indicate that two elements are in direct contact, or that there are other elements between the two elements. In addition, terms such as "first" and "second" are also used to describe individual elements, areas, parts, etc., and should not be considered limiting. Similar terms are used throughout the description to refer to similar elements.

[0039] It will be apparent to those skilled in the art that the present invention can be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0040] Existing designs for retractable landing mechanisms suffer from problems such as long design iteration cycles, inability to consider the combined effects of pneumatic drive and mechanical systems in deployment process analysis, and low design efficiency. To address these technical issues, this invention proposes an optimized design method for the deployment process of retractable landing mechanisms.

[0041] See Figure 1 The present invention provides an optimized design method for the deployment process of a retractable landing mechanism, which includes at least the following steps:

[0042] S100. Determine the dimensional parameters and mass characteristics of the main outriggers and auxiliary outriggers in the retractable landing mechanism;

[0043] S200. Determine the parameters required for kinematic calculations of each component in the retractable landing mechanism;

[0044] S300. Determine the deployment control method, design parameters, and loads experienced by the retractable landing mechanism during deployment.

[0045] S400. Determine the parameters to be optimized and their ranges in the design parameters according to the design scheme;

[0046] Based on S100, S200 and S300, a parameterized and modular retractable landing mechanism pressure-mechanical structure joint dynamic model is established using system simulation software;

[0047] S600. Determine the optimization algorithm, optimization objective and constraints, and build the optimization analysis process and compile the process for extracting calculation results in the system simulation software;

[0048] The process of running the S700, driving air pressure-mechanical structure joint dynamic model, optimization analysis process and extraction of calculation results, the parameterized model batch calculation and extraction of calculation results, and the convergence condition of the optimization algorithm to determine whether the calculation results meet the constraints.

[0049] S800 If the calculation result does not meet the constraints, the optimization algorithm will be used to automatically optimize and adjust the parameters to be optimized, and the operation of S700 will be repeated until the calculation result meets the constraints and the optimization goal is achieved.

[0050] Furthermore, the dimensional parameters and mass characteristics of the main support leg and the auxiliary support leg in S100 include at least the following: the number of stages of the multi-stage sleeve of the main support leg, the diameter, length, mass, center of mass position, and moment of inertia of each stage sleeve; and the overall length, mass, center of mass position, and moment of inertia of the auxiliary support leg. The moment of inertia is the moment of inertia of each component about its center of mass.

[0051] A schematic diagram of the retractable landing mechanism in the S100 is attached. Figure 2The system mainly includes a main outrigger structure, a secondary outrigger structure, and connection structures 2 and 8 connecting the main outrigger to the carrier 1 and 8 respectively. The main outrigger consists of a retractable multi-stage sleeve structure (first-stage sleeve 3, second-stage sleeve 4, and third-stage sleeve 5) and an internal locking structure. Each pair of sleeves in the first-stage sleeve 3, second-stage sleeve 4, and third-stage sleeve 5 forms a structure similar to a cylinder or hydraulic cylinder to facilitate the deployment and retraction of the mechanism. The air vent controls the deployment speed, and the internal locking structure limits and locks the travel to the desired position. A foot pad 6 is installed at the connection point between the secondary outrigger 7 and the main outrigger. The secondary outrigger 7 and foot pad 6 work together to cover the entire landing mechanism to form a better aerodynamic shape when retracted, and to assist in supporting the overall structure and providing cushioning during landing when deployed.

[0052] Furthermore, S200 determines that the kinematic calculation parameters required for each component in the retractable landing mechanism include at least the following: the mounting positions of the main outriggers and auxiliary outriggers on the vehicle, as well as the relative positions, kinematic pair positions, and kinematic pair types between the components of the main outriggers and auxiliary outriggers.

[0053] Furthermore, S300 specifies the deployment control method, design parameters, and loads experienced during the deployment process of the retractable landing mechanism. The deployment control method employs a pneumatic drive control system. Design parameters include at least: the diameters of each stage of the cylinders and pushrods between the main outriggers' multi-stage sleeves, the stroke of each stage of the cylinders, the diameters and lengths of the inlet and outlet ports of each stage of the cylinders, the timing of control signals, the type of gas, the capacity and pressure of the gas cylinders, and the orifice area of ​​the solenoid valves. Loads experienced during the deployment process include at least: the aerodynamic loads acting on the landing mechanism during deployment, the frictional and damping forces between the kinematic pairs, as well as external air pressure, overload acceleration, and the attitude angle load parameters of the landing mechanism.

[0054] In step S300, the deployment control method of the retractable landing mechanism mainly refers to the pneumatic drive control method. Possible control methods include, but are not limited to: Method 1, actively controlling the deployment by pressurizing the gas cylinder within the multi-stage sleeve of the main outriggers; Method 2, assisting the deployment of the landing mechanism by pre-filling the multi-stage sleeve of the main outriggers with gas at a certain pressure; Method 3, assisting the deployment of the landing mechanism by adding a deployment drive push rod and pressurizing the push rod; Method 4, deploying the landing mechanism solely based on the effect of landing overload.

[0055] Furthermore, the timing of the control signal in step S300 refers to the start time and duration of the air supply from the pneumatic drive system.

[0056] See Figure 3In one embodiment, S500, based on steps one, two, and three, establishes a parameterized and modular pneumatic-mechanical joint dynamic model of the retractable landing mechanism using system simulation software. Specifically, it establishes a parameterized and modular pneumatic-mechanical joint dynamic model of the retractable landing mechanism by combining the dimensional parameters and mass characteristics of each part of the landing mechanism in S100, the kinematic calculation parameters required for each component of the retractable landing mechanism in S200, and the deployment control method, design parameters, and loads experienced during the deployment process of the retractable landing mechanism in S300.

[0057] The retractable landing mechanism's pneumatic-mechanical joint dynamics model includes at least a control module, a pneumatic system module, and a mechanical system module. The control module is used for the timing control of cylinder movements, as well as the acquisition of arrival time and speed. The pneumatic system module receives signals from the control module and simulates cylinder movement. The mechanical system module includes the main outrigger structure, the auxiliary outrigger structure and their components, as well as kinematic pairs and sensors. The mechanical system module defines the overall coordinate system, the magnitude and direction of the gravity field, and the spatial positions, mass characteristics, and relative motion relationships of each mechanical component. It also simulates the overall deployment process of the landing mechanism and extracts the required motion parameters. In this embodiment, the control module drives the pneumatic system module, and the simulated cylinder movement drives the outrigger structure in the mechanical system module to open, thereby simulating the overall deployment of the landing mechanism.

[0058] This invention provides an optimized design method for the deployment process of a retractable landing mechanism. It simplifies the mechanical and pneumatic drive structures in the landing mechanism and establishes a parameterized pneumatic-mechanical system joint dynamic model. The deployment process of the landing mechanism is calculated using system simulation software, which solves the problem that the existing technology cannot consider the combined effect of the pneumatic drive system and the mechanical system.

[0059] The combined pneumatic-mechanical system dynamics model in this embodiment achieves parameterized and modular construction of each component. Components can be added or removed as needed, and control schemes and design parameters can be adjusted, significantly improving modeling efficiency. Furthermore, this embodiment utilizes the parameter optimization function of simulation software to optimize and batch-process adjustable design parameters, analyzing and determining the optimal parameters that satisfy the deployment process constraints and optimization objectives. This greatly improves the design efficiency of the landing mechanism, shortening the cycle from one to two months required by traditional landing mechanism design methods to two to three days.

[0060] In any of the above embodiments, the parameters to be optimized, the optimization algorithm, the constraints, and the optimization objective are all customized according to design requirements.

[0061] See also Figure 3Furthermore, the pneumatic system module includes: a gas cylinder, a solenoid valve, a gas pipeline, a primary cylinder, and a secondary cylinder. The gas cylinder is connected to the primary and secondary cylinders respectively via a solenoid valve installed on the gas pipeline. The solenoid valve is controlled by a control module. In this embodiment, the main support leg structure includes a primary sleeve, a secondary sleeve, and a tertiary sleeve. The primary cylinder is used to simulate the extension of the primary and secondary sleeves, and the secondary cylinder is used to simulate the extension of the secondary and tertiary sleeves. The control module includes: a signal source, a data calculation module, a logic judgment module, and a clock module, used for timing control of cylinder actions and acquisition of arrival time and speed.

[0062] The kinematic relationships of the components in the mechanical system are shown below. Figure 3 The main outrigger's fulcrum is located at the origin of the coordinate system. One end of the first-stage sleeve is hinged to the main outrigger's fulcrum via a revolute joint, and the other end is connected to the second-stage sleeve via a cylinder joint and a translational joint, where the cylinder joint is driven by the first-stage cylinder in the pneumatic system. The other end of the second-stage sleeve is connected to the third-stage sleeve via a cylinder joint and a translational joint, where the cylinder joint is driven by the second-stage cylinder in the pneumatic system. The other end of the third-stage sleeve is hinged to the auxiliary outrigger via a revolute joint, and the other end of the auxiliary outrigger is hinged to the auxiliary outrigger's fulcrum via a revolute joint. This constitutes the overall motion model.

[0063] Furthermore, the mechanical system model is equipped with an angle sensor and a speed sensor on the secondary outrigger. When the angle of the secondary outrigger reaches the maximum deployment angle, the time of the clock module is captured by the control module. This time is the deployment time of the landing mechanism. At the same time, the control module records the translational velocity of the three-stage sleeve hinge position of the secondary outrigger and the main outrigger at this moment and performs vector synthesis to obtain the deployment speed of the landing mechanism.

[0064] In one embodiment, the deployment process load conditions in S500 include load parameters such as external air pressure, overload acceleration, and attitude angle of the landing mechanism.

[0065] Furthermore, the calculation results extracted from S600 mainly include the speed and time of the landing mechanism's deployment into position. The deployment speed refers to the velocity of the end of the main outrigger furthest from the launch vehicle relative to the ground when it reaches its maximum deployment stroke. The deployment time refers to the time required from the start of the main outrigger's deployment action to its final deployment position.

[0066] Furthermore, the parameter optimization algorithm in S700 can select from a variety of optimization algorithms, including but not limited to sequential quadratic programming and genetic algorithms, and different optimization algorithms and parameters can be selected for different instances.

[0067] refer to Figure 4 The flowchart is shown below. The following is an example of the implementation steps of a specific embodiment:

[0068] Step 1: Determine the preliminary design scheme of the retractable landing mechanism. The main outriggers are three-stage sleeves. The diameter, length, mass, and moment of inertia of each stage of the main outrigger sleeve are shown in Table 1. The overall length, mass, and moment of inertia of the auxiliary outriggers are shown in Table 1. The center of mass of the main outriggers is located at the geometric center of each sleeve. The vertical distance H1 = 4200 mm and the horizontal distance L1 = 2460 mm between the center of mass of the auxiliary outriggers and the installation position of the main outriggers are the same.

[0069] parameter Diameter / mm Length / mm mass / kg <![CDATA[Moment of inertia / kg·m 2 > First-stage sleeve 400 2500 100 100 Second-stage sleeve 300 2300 100 100 Third-stage sleeve 250 3000 200 200 Secondary support legs -- 6800 500 2000

[0070] Table 1

[0071] Step 2: Determine the kinematic parameters required for the retractable landing mechanism: Taking the main outrigger's installation position on the launch vehicle as a reference point, the vertical distance H2 from the main outrigger's installation position is 2500mm, and the horizontal distance L2 is 635mm. Specifically, one end of the first-stage sleeve of the main outrigger is connected to the launch vehicle wall via a revolute joint, and the other end is connected to the second-stage sleeve via a translational joint. The other end of the second-stage sleeve is connected to the third-stage sleeve via a translational joint. Similarly, one end of the secondary outrigger is connected to the launch vehicle wall via a revolute joint, and the other end is connected to the third-stage sleeve of the main outrigger via a revolute joint.

[0072] Step 3: Determine that the deployment control method of the designed retractable landing mechanism is pneumatic drive control. The first stage of the main outrigger multi-stage sleeve deploys via an active control mechanism that pressurizes the gas cylinder, while the second stage cylinder inlet is sealed. Therefore, the design parameters for the pneumatic system are as follows: gas cylinder capacity 150L, ​​gas cylinder pressure as an optimized parameter (initial value 1MPa), gas is nitrogen, and the orifice area of ​​the solenoid valve is 314mm². 2 The air supply control signal timing is as follows: air supply begins 0.8 seconds after the deployment process starts and continues until the landing mechanism is fully deployed. During the deployment process, the structure experiences a downward acceleration a = 9.8 m / s². 2 Without considering the influence of resistance, the loads experienced during the deployment process were determined. The initial values ​​of the relevant parameters for the cylinder and piping are shown in Table 2.

[0073] parameter Piston diameter / mm push rod diameter / mm Trip / mm Inlet diameter / mm Intake pipe length / mm Vent diameter / mm Air outlet pipe length / mm First stage cylinder 400 300 1800 20 5000 10 500 Second stage cylinder 300 250 1900 0 0 10 500

[0074] Table 2

[0075] Step 4: Determine the adjustable parameters and parameter ranges in the design parameters of Steps 1, 2, and 3 based on the design scheme, as shown in Table 3.

[0076] Adjustable parameters First-stage cylinder exhaust port diameter / mm Second-stage cylinder exhaust port diameter / mm Cylinder pressure / MPa First-stage cylinder exhaust port length / mm Second-stage cylinder exhaust port length / mm lower limit value 1 1 1 100 100 Upper limit 20 20 3 1000 1000

[0077] Table 3

[0078] Step 5: Using system simulation software, combine the dimensional parameters and mass characteristics of each part of the landing mechanism, the position and type of kinematic pairs, the pneumatic drive control method, and the load conditions during the deployment process from Step 1, Step 2, and Step 3 to establish a parameterized pneumatic-mechanical system joint dynamic model.

[0079] Step 6: Use system simulation software to develop a process for extracting calculation results. The extracted results are the deployment time and speed of the retractable landing mechanism.

[0080] Step 7: The optimization algorithm was determined to be a genetic algorithm, with the optimization objective being to minimize the deployment speed and the constraint that the deployment time must be less than or equal to 5 seconds. The optimization analysis program was run in the system simulation software, and after 486 rounds of iterative optimization, the parameter optimization results are shown in Table 4.

[0081] Adjustable parameters First-stage cylinder exhaust port diameter / mm Second-stage cylinder exhaust port diameter / mm Cylinder pressure / MPa First-stage cylinder exhaust port length / mm Second-stage cylinder exhaust port length / mm optimal value 8.6 7.7 1.50 667 474

[0082] Table 4

[0083] The total calculation time was approximately 26 hours. The optimization results are as follows: the deployable landing mechanism has a deployment speed of 0.35 m / s and a deployment time of 3.22 s, which meets the design requirements.

[0084] In one embodiment, when designing the structural design of the retractable landing mechanism of the present invention, an extension drive push rod may be added as needed to assist the deployment of the landing mechanism, a landing buffer device may be added to improve the buffering performance of the landing mechanism under impact during landing or deployment, and a locking structure may be added to fix the retracted state to the carrier.

[0085] In any of the above embodiments, the deployment control method of the landing mechanism can at least partially replace pneumatic drive control with hydraulic drive control.

[0086] The above embodiments can be combined with each other and have corresponding technical effects.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for optimizing the deployment process of a retractable landing mechanism, characterized in that, At least the following steps are included: Step 1: Determine the dimensional parameters and mass characteristics of the main and auxiliary outriggers in the retractable landing mechanism; Step 2: Determine the parameters required for kinematic calculations of each component in the retractable landing mechanism; Step 3: Determine the deployment control method, design parameters, and loads experienced by the deployable landing mechanism during deployment; Step 4: Determine the parameters to be optimized and their ranges in the design parameters based on the design scheme; Step 5: Based on Step 1, Step 2 and Step 3, establish a parameterized and modular barometric-mechanical joint dynamic model of the retractable landing mechanism using system simulation software; Step 6: Determine the optimization algorithm, optimization objective, and constraints, and build the optimization analysis process and develop the process for extracting calculation results in the system simulation software; Step 7: Run the combined dynamic model of the pneumatic-mechanical structure, the optimization analysis process, and the process of extracting calculation results. After batch calculation of the parameterized model, extract the calculation results and judge whether the calculation results meet the constraints by the convergence conditions of the optimization algorithm. Step 8: If the calculation result does not meet the constraints, the optimization algorithm will be used to automatically optimize and adjust the parameters to be optimized, and the operation of Step 7 will be repeated until the calculation result meets the constraints and the optimization goal is achieved.

2. The method for optimizing the deployment process of the retractable landing mechanism according to claim 1, characterized in that, The dimensional parameters and mass characteristics of the main support leg and the auxiliary support leg in step one include at least the number of stages of the multi-stage sleeve of the main support leg, the diameter, length, mass, center of mass position and moment of inertia of each stage sleeve; and the overall length, mass, center of mass position and moment of inertia of the auxiliary support leg.

3. The method for optimizing the deployment process of the retractable landing mechanism according to claim 1, characterized in that, The parameters required for the kinematic calculation of each component in step two include at least: the installation position of the main outrigger and the auxiliary outrigger on the carrier, as well as the relative position, kinematic pair position, and kinematic pair type between the components of the main outrigger and the auxiliary outrigger.

4. The method for optimizing the deployment process of the retractable landing mechanism according to claim 1, characterized in that, In step three, the deployment control method adopts a pneumatic drive control method; The design parameters include the diameter of each stage of cylinders and push rods between the main support legs and the multi-stage sleeves, the stroke of each stage of cylinders, the diameter and length of the air inlet and outlet of each stage of cylinders, the timing of control signals, the type of gas, the capacity and pressure of the gas cylinder, and the throttling orifice area of ​​the solenoid valve. The loads experienced during the deployment process include at least: the aerodynamic loads acting on the landing mechanism during deployment, the friction and damping forces between the kinematic pairs, as well as the external air pressure, overload acceleration, and attitude angle load parameters of the landing mechanism.

5. The method for optimizing the deployment process of a retractable landing mechanism according to any one of claims 1 to 4, characterized in that, The combined baro-mechanical dynamics model of the retractable landing mechanism in step five includes at least: The control module is used for the timing control of cylinder movements, as well as the acquisition of arrival time and arrival speed. The pneumatic system module receives signals from the control module to simulate the movement of the cylinder; The mechanical system module includes the main outrigger structure, the auxiliary outrigger structure and their components, as well as kinematic pairs and sensors; it is used to define the overall coordinate system, the magnitude and direction of the gravitational field, and the spatial position, mass characteristics and relative motion relationships of each mechanical component, and to simulate the overall deployment motion process of the landing mechanism and extract the required motion parameters. During the operation of the combined pneumatic-mechanical dynamics model of the retractable landing mechanism, the control module is used to drive the pneumatic system module to move, and drives the outrigger structure in the mechanical system module to open through the simulated cylinder, thereby simulating the overall deployment of the landing mechanism.

6. The method for optimizing the deployment process of the retractable landing mechanism according to claim 5, characterized in that, The parameters to be optimized, the optimization algorithm, the constraints, and the optimization objective are all customized according to design requirements.

7. The method for optimizing the deployment process of the retractable landing mechanism according to claim 6, characterized in that, The pneumatic system module includes: a gas cylinder, a solenoid valve, a gas pipeline, a primary cylinder, and a secondary cylinder; the gas cylinder is connected to the primary cylinder and the secondary cylinder respectively through the solenoid valve installed on the gas pipeline; The control module controls the opening and closing of the solenoid valve; after the solenoid valve is opened, the gas in the gas cylinder fills the first-stage cylinder and the second-stage cylinder. After filling is completed, the control module controls the solenoid valve to close; after the first-stage cylinder and the second-stage cylinder are filled, they drive the main support leg structure to unfold.

8. The method for optimizing the deployment process of the retractable landing mechanism according to claim 7, characterized in that, The calculation results extracted in step six mainly include the speed and time of the landing mechanism deploying into position; The speed at which the main outriggers are deployed refers to the speed of the end of the main outriggers furthest from the launch vehicle relative to the ground when the main outriggers of the landing mechanism reach their maximum deployment stroke. The time for deployment refers to the time required for the main outriggers of the landing mechanism to begin their deployment action and reach full deployment.

9. The method for optimizing the deployment process of the retractable landing mechanism according to claim 2, characterized in that, The moment of inertia is the moment of inertia of each component about its center of mass.

10. The method for optimizing the deployment process of the retractable landing mechanism according to claim 1, characterized in that, The optimization algorithm is selected from, but is not limited to, a sequential quadratic programming algorithm and a genetic algorithm.

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