An aerodynamic linkage mechanism collaborative simulation method based on an FMI standard, an electronic device, and a storage medium

Abstract

The application discloses a kind of based on FMI's pneumatic connecting rod collaborative simulation method, electronic equipment and storage medium, comprising: in multidisciplinary simulation software, establish gas power source model;Coupling data interface of gas power source model and connecting rod mechanism multibody dynamics model is configured, and after being configured, gas dynamic power source FMU model is exported;In multibody dynamics simulation software, establish connecting rod mechanism multibody dynamics simulation model;Coupling data interface of connecting rod mechanism mechanism multibody dynamics model and gas power source model is configured;Gas dynamic power source FMU file is imported into the software in which connecting rod mechanism multibody dynamics model is located;Simulation condition is set, and collaborative simulation is carried out.The application utilizes FMI collaborative simulation technology to realize the collaborative simulation of gas source and mechanical mechanism of pneumatic connecting rod mechanism, establishes pneumatic-mechanical coupling model, and the dynamic characteristics of pneumatic connecting rod mechanism are simulated by numerical simulation tool, to ensure that output track meets engineering precision requirement.

Description

Technical Field

[0001] This invention belongs to the field of pneumatic linkage simulation technology, specifically a collaborative simulation method for pneumatic linkage mechanisms based on the FMI standard. Background Technology

[0002] FMI (Functional Mock-up Interface) Co-simulation 2.0 is a standardized interface protocol for multidisciplinary co-simulation, designed to address challenges in complex system simulation such as tool fragmentation, low model reusability, and intellectual property protection. It has become one of the most widely accepted simulation model interaction standards globally. Its core idea is to encapsulate models through FMU (Functional Mock-up Unit), transforming subsystems from different fields such as aerodynamics and mechanics into independent modules, achieving seamless cross-platform integration.

[0003] FMI Co-simulation 2.0 employs a master-slave distributed solver architecture: the master (e.g., multibody dynamics software) is responsible for global time step progression and data synchronization, while the slave (e.g., air source FMU) independently calculates the dynamic characteristics of subsystems through its built-in solver and uses the fmi2DoStep function to achieve variable interaction at discrete time points (e.g., pressure, displacement feedback). This mechanism supports fixed / variable step size modes and utilizes interpolation algorithms to solve the problem of inconsistent step sizes, significantly improving the efficiency and accuracy of aerodynamic-mechanical coupled simulations. Furthermore, FMI 2.0 introduces dynamic parameter adjustment (via the fmi2SetReal function), physical quantity unit verification, and zero-crossing event detection functions to ensure the consistency and robustness of simulation data. Currently, FMI Co-simulation 2.0 has been widely adopted in the automotive, aerospace, and other fields, supporting over 170 tools (such as SimulationX, Adams, and MATLAB), providing a standardized technical framework for multiphysics joint verification of complex systems such as aerodynamic linkages and vehicle suspensions.

[0004] Pneumatic linkage mechanisms are devices that use compressed gas as a power source, driving linkages through actuators such as cylinders or pneumatic motors to achieve specific trajectory movements. They are widely used in production due to their rapid response, high dynamic characteristics, overload protection capabilities, and flexible adjustability under different working conditions. Because pneumatic linkage mechanisms encompass multiple fields such as mechanics, fluid dynamics, and control, the piston rod thrust decreases as the stroke increases, and the piston rod resistance also changes with the movement of the linkage mechanism. This makes the dynamic analysis process complex and highly nonlinear. Traditional dynamic simulation analysis relies heavily on theoretical formulas to establish dynamic simulation models, which is insufficient for establishing accurate, efficient, and easily solvable mathematical models for such optimization design problems. Summary of the Invention

[0005] The purpose of this invention is to address the problems of low optimization efficiency and difficulty in accurately obtaining the dynamic characteristics of linkage mechanisms caused by the reliance on graphical and analytical methods in existing pneumatic linkage mechanism design methods. To achieve the above objective, this application proposes a pneumatic linkage co-simulation method based on the FMI standard, which establishes a gas power source model and a linkage structure model and performs joint simulation, thereby obtaining more realistic dynamic characteristics of the pneumatic linkage mechanism.

[0006] The method includes the following steps:

[0007] S1. Establish a gas power source model in multidisciplinary simulation software;

[0008] S2. Configure the coupling data interface between the gas power source model and the multibody dynamics model of the linkage mechanism, and export the gas power source FMU model after configuration;

[0009] S3. Establish a multibody dynamics model of the linkage mechanism in multibody dynamics simulation software;

[0010] S4. Configure the coupling data interface between the multibody dynamics model of the linkage mechanism and the gas power source model;

[0011] S5. Import the gas power source FMU model file into the software containing the multibody dynamics model of the linkage mechanism, and configure the coupling data;

[0012] S6. Set the co-simulation conditions and perform co-simulation.

[0013] In some possible embodiments, the gas power source model includes, in sequence, the compressed gas mass flow rate initial condition, the qSource gas source component, the voume chamber component, the constThrottle valve component, the Cylinder cylinder component, the exhaust component, the mass block component, and the preset component.

[0014] In some possible embodiments, the configured gas power source model selects the cylinder piston rod speed as the input condition; the configured gas power source model transmits the piston rod thrust and cylinder end pressure monitored in the cylinder assembly to the multibody dynamics model of the linkage mechanism as the initial conditions of the multibody dynamics model of the linkage mechanism.

[0015] In some possible embodiments, the parameters of each component in the gas power source model (gas mass flow rate, chamber exhaust temperature, chamber volume, cylinder maximum stroke, cylinder inner diameter, piston rod diameter) are set as variables, and the gas power source FMU model is exported after configuration.

[0016] In some possible embodiments, the various components within the gas power source model are linked together via pneumatic connections, with carbon dioxide selected as the gas medium in the pneumatic connections.

[0017] In some possible embodiments, the constructed multibody dynamics model of the linkage mechanism includes a piston rod, a piston rod buffer device, a push rod, a connecting rod, a crank, a rocker arm, and a speed detection sensor.

[0018] In some possible embodiments, the piston rod velocity and piston rod displacement detected by the velocity detection sensor are transmitted to the gas power source FMU model as cylinder input conditions.

[0019] In some possible instances, the piston rod thrust and cylinder pressure derived from the gas power source model are connected to the piston rod velocity and displacement from the multibody dynamics model of the linkage mechanism according to the corresponding relationship.

[0020] In some possible implementations, the co-simulation step size and co-simulation time are configured, offline time-domain analysis is performed in Simpackpre, and the post-processing software is opened to view the co-simulation results.

[0021] In some possible embodiments, the coupling relationship between the gas power source model and the multibody dynamics model of the linkage mechanism during co-simulation is as follows:

[0022] Gas power source model:

[0023]

[0024] in These are the piston rod thrust and the pressure on both sides of the cylinder calculated by the gas power source model at time n+1, respectively. These are the piston rod velocity and piston rod displacement calculated for the linkage mechanism model at time n, respectively.

[0025] Multibody dynamics model of linkage mechanism:

[0026]

[0027] in These are the piston rod velocity and piston rod displacement calculated for the linkage mechanism model at time n+1, respectively. These are the piston rod push and the pressure on both sides of the cylinder calculated by the gas power source model at time n.

[0028] On the other hand, the present invention provides an electronic device, including a processor and a memory;

[0029] Memory is used to store programs;

[0030] The processor executes the program as described above.

[0031] On the other hand, the present invention provides a computer-readable storage medium storing a program that is executed by a processor to implement the method described above.

[0032] The present invention also discloses a computer program product or computer program comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned method.

[0033] The present invention has the following technical effects or advantages:

[0034] Improved accuracy of multiphysics coupling modeling: By integrating the gas source dynamic model (including gas compressibility effect) with the linkage mechanism model in multibody dynamics software across platforms, the problem that traditional graphical and analytical methods cannot capture the coupling between aerodynamic nonlinearity and mechanical inertia is solved; a master-slave distributed solution architecture is adopted, with the master end executing global time step advancement and the slave end independently calculating aerodynamic equations through built-in solvers, which significantly improves the dynamic response accuracy of gas-machine energy exchange, and the simulation error is reduced by more than 60% compared with traditional empirical design;

[0035] By encapsulating the aerodynamic model in an FMU file (including XML interface description and compiled C code), this method ensures the confidentiality of commercial algorithms while achieving seamless integration with mainstream multibody dynamics tools such as Adams and RecurDyn. Compared to pure kinematic analysis, this method integrates aerodynamic, mechanical, and control characteristics, providing a high-fidelity virtual verification platform for the reliability design of mechanisms under high-speed variable load conditions.

[0036] This invention utilizes FMI (Flexible Interaction Modeling) co-simulation technology to achieve co-simulation of the air source and mechanical mechanism of a pneumatic linkage mechanism. It employs parametric modeling and a multidisciplinary approach to establish a coupled pneumatic-mechanical model. Numerical simulation tools are then used to analyze the dynamic characteristics of the pneumatic linkage mechanism, ensuring that the output trajectory meets engineering accuracy requirements. This process overcomes the limitations of traditional empirical design and significantly improves the ability to predict and control the dynamic performance of the mechanism.

[0037] By encapsulating models, employing distributed solving, and using multiphysics coupling mechanisms, high-fidelity integration of aerodynamic subsystems and mechanical dynamics is achieved. This technology significantly improves the simulation efficiency and accuracy of complex systems, provides a standardized verification platform for the dynamic characteristic analysis and control strategy optimization of pneumatic actuators, and is of great significance for the optimized design of pneumatic linkage mechanisms. Attached Figure Description

[0038] Figure 1The flowchart shows the FMI-based aerodynamic linkage co-simulation method in this application example;

[0039] Figure 2 This is a simulation model diagram of the gas power source in the example of this application;

[0040] Figure 3 These are the parameters of the FMU file exported from the gas dynamic source model in this application example;

[0041] Figure 4 This is a diagram of the multibody dynamics simulation model in the example of this application;

[0042] Figure 5 This is a simulation diagram of the pneumatic linkage motion in the example of this application;

[0043] Figure 6 This is a piston rod thrust-time curve diagram in an example of this application;

[0044] Figure 7 This is a force-time curve at the hinge point between the connecting rod, rocker arm and frame in the example of this application;

[0045] Figure 8 This is the rate-time curve of the load increase in this application instance. Detailed Implementation

[0046] The accompanying drawings in the embodiments clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0048] This embodiment discloses an example of a collaborative simulation method for a parallel four-bar lifting mechanism powered by compressed carbon dioxide. Figure 1 This is a flowchart illustrating an example of the invention.

[0049] A pneumatic linkage co-simulation method based on the FMI standard includes the following steps:

[0050] S1. Based on the design requirements of the gas power source device, establish a gas power source model in SimulationX software.

[0051] Specifically, such as Figure 2 As shown, in this step, when building the gas source power model, the model is connected in the following order: initial conditions for compressed gas mass flow rate, qSource gas source component, volume chamber component, constThrottle valve component, Cylinder cylinder component, exhaust component, mass mass block component, and preset component. The parameters are set as follows: 3 kg of carbon dioxide working fluid, and 0.046 m³ of chamber volume. 3 The pressure relief valve has a relief temperature of 400K, the maximum cylinder stroke is 1.8m, the cylinder diameter is 0.25m, and the piston rod diameter is 0.1m. A separate simulation test was conducted in SimulationX. The program ran successfully, and the cylinder output pressure change trend was consistent with that of a real power unit. The next step is then proposed.

[0052] In the gas kinetic energy source model, the work process of carbon dioxide as the working fluid is described by the Redlich-Kwong real gas law, the general form of which is shown below:

[0053]

[0054] In the formula, P This refers to gas pressure. R The gas constant is T For temperature, V m Let be the molar volume of the gas. a This is the molecular attraction correction constant. b This is the volume correction constant. Compared to the van der Waals equation of state, the above equation of state can more accurately describe the work done by the expansion of compressed carbon dioxide.

[0055] S2. Configure the coupling data interface between the gas power source model and the multibody dynamics model of the linkage mechanism, and export the Co-Simulation FMU model after configuration.

[0056] Specifically, the monitored pressures on both sides of the cylinder and the piston rod thrust are transmitted to the multibody dynamics simulation model of the connecting rod mechanism as its input conditions; the monitored piston rod displacement of the connecting rod mechanism is used as the input condition for the gas power source model. The parameters of each component in the model (gas mass flow rate, chamber exhaust temperature, chamber volume, maximum cylinder stroke, cylinder bore, and piston rod diameter) are set as variables, with specific parameters as follows: Figure 3 The configuration shown is used to export the gas power source FMU model after completion.

[0057] Specifically, in the SimulationX software, click the Export-C-Code menu. Select FMI Co-Simulation2.0, specify the inputs (cylinder piston rod speed), outputs (cylinder force), and parameters. Generate the fmu file in Code Generation, and finally compile it in Position processing.

[0058] S3. Establish a multibody dynamics simulation model of the linkage mechanism in Simpack software.

[0059] Specifically, such as Figure 4 As shown, this embodiment employs a four-bar linkage, comprising: a front rocker arm 1 (driving link), a rear rocker arm 2 (driven link), a push rod 3, a connecting rod 4, and a piston rod 5 as the driving mechanism. Using Simpack software, a multibody dynamics model is created following these steps: Five rigid bodies are created sequentially through the graphical interface, corresponding to the five links mentioned above, and each rigid body is assigned design values ​​for parameters such as mass, center of mass coordinates, and moment of inertia; additional rigid bodies are added to the upper ends of the front rocker arm 1 and the rear rocker arm 2 to equivalently simulate the load applied to the mechanism during lifting; hinged joints are established at the connections of each link; a driving force element is applied to the end of the piston rod 5, providing the mechanism with a driving input along the piston axis; contact force elements are created in the contact areas between the two rockers and the load to transmit the power of the linkage mechanism to the load; the simulation runtime, sampling frequency, and solver parameters are set, and after configuration, the test model is run and the results are verified.

[0060] Specifically, create joint element 4: Revolute ga, hinge the front and rear rocker arms to the frame (geocentric coordinate system), and create joint element 4: Prismatic x, restricting the piston rod to move in only one direction. Set parameters such as rod length and relative positional relationships as variables for easier subsequent parameter optimization. To simplify the model, set the push rod and connecting rod as massless constraint connections, with the push rod hinged at both ends to the front rocker arm and piston rod respectively, and the connecting rod hinged at both ends to the front and rear rocker arms. Create joint25: User Defined, and set the contact between the load and the four-bar linkage. Create Forceelement 100: Proportional Actuator Cmp, and set... Figure 4 The specific drive signal shown is designated as the input signal.

[0061] Configure the solver, set the running time to 1.5s, the output sampling frequency to 200Hz, and run the solver.

[0062] S4. Configure the coupling data interface between the multibody dynamics model of the linkage mechanism and the gas power source model.

[0063] Specifically, the following steps are executed sequentially in the multibody dynamics model of the linkage mechanism: a kinematic measurement unit is established to acquire the linear velocity signal of the piston rod in real time; the acquired piston rod velocity signal is mapped to the UI_pos input variable of the pneumatic power model to realize closed-loop drive control.

[0064] The coupling relationship between the gas power source model and the multibody dynamics model of the linkage mechanism during co-simulation is as follows:

[0065] Gas power source model:

[0066]

[0067] in These are the piston rod thrust and the pressure on both sides of the cylinder calculated by the gas power source model at time n+1, respectively. These are the piston rod velocity and piston rod displacement calculated for the linkage mechanism model at time n, respectively.

[0068] Multibody dynamics model of linkage mechanism:

[0069]

[0070] in These represent the piston rod velocity and piston rod displacement calculated for the linkage mechanism model at time n+1, respectively. These are the piston rod thrust and the pressure on both sides of the cylinder calculated by the gas power source model at time n, respectively.

[0071] The data exchange and parameter settings between models are shown in Table 1 below.

[0072] Table 1

[0073]

[0074] S5. Import the gas power source FMU file into the software containing the multibody dynamics model of the linkage mechanism.

[0075] Specifically, a control module is created in Simpack, a gas dynamic source model is imported through the Functional Model Interface (FMI), the corresponding .fmu file is loaded, its default parameters are automatically extracted, and the cylinder thrust in the FMU is set as the input parameter of the multibody dynamics model, while the piston rod speed and displacement are used as output parameters.

[0076] S6. Set simulation conditions and perform co-simulation.

[0077] In some preferred embodiments, the inter-model communication sampling time is set to 0.0001 s, and the total co-simulation time is set to 1.5 s; during this period, the pneumatic linkage mechanism completes the entire erection and retraction process. After the offline time-domain analysis is completed, the following simulation results are output:

[0078] like Figure 5 As shown, the high-pressure gas expands and does work, pushing the piston rod to extend; the piston rod drives the load to stand upright through the connecting rod mechanism; after standing upright, the pressure relief valve opens, the pressure difference on both sides of the piston decreases rapidly, the connecting rod and the load fall back under the action of gravity, and push the piston rod to retract until the mechanism returns to its initial position.

[0079] Figure 6 The piston rod thrust-time curve is given: the thrust reaches its peak rapidly in the early stage of expansion, and then gradually decreases to zero as the gas expands; the thrust is negative in the recovery stage (due to the gravity of the connecting rod), and finally returns to zero.

[0080] Figure 7 The force-time curves at the hinge point of the front and rear rocker arms are given. The force amplitude of the rear rocker arm (dashed line) is significantly greater than that of the front rocker arm. Therefore, the rear rocker arm can be reinforced in the design of the linkage.

[0081] Figure 8 The load increase rate-time curve is given, indicating that the increase process is smooth and without abrupt changes.

[0082] On the other hand, embodiments of the present invention provide an electronic device, including a processor and a memory;

[0083] Memory is used to store programs;

[0084] The processor executes the program as described above.

[0085] On the other hand, embodiments of the present invention provide a computer-readable storage medium storing a program that is executed by a processor to implement the method described above.

[0086] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned method.

[0087] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pneumatic linkage co-simulation method based on the FMI standard, characterized in that: Includes the following steps: S1. Based on the design requirements of the gas power source device, a gas power source model is established in a multidisciplinary simulation software. The gas power source model includes the gas mass flow initial conditions, gas source components, chamber components, cylinder components, exhaust components, mass block components, and preset components connected in sequence. S2. Configure the data interface coupled with the multibody dynamics model of the linkage mechanism in the gas power source model, and export the gas power source FMU model after configuration. The configuration of the coupled data interface includes: selecting the cylinder piston rod speed as the input condition, setting the piston rod thrust and cylinder end pressure monitored in the cylinder assembly as the initial conditions for output to the multibody dynamics model of the linkage mechanism, and setting the parameters of each component in the gas power source model as variables during export, and generating an FMU file that conforms to the FMICo-Simulation 2.0 standard; S3. Establish a multibody dynamics model of the linkage mechanism in multibody dynamics simulation software. The multibody dynamics model of the linkage mechanism includes a piston rod, a piston rod buffer device, a push rod, a connecting rod, a crank, a rocker arm, and a speed detection sensor for detecting the speed and displacement of the piston rod. S4. Configure a data interface coupled with the gas power source model in the multibody dynamics model of the linkage mechanism, specifically: set the piston rod velocity and piston rod displacement detected by the velocity detection sensor as the input conditions for output to the gas power source FMU model; S5. Import the gas power source FMU model file into the software containing the multibody dynamics model of the linkage mechanism, configure the coupling data, and connect the piston rod thrust and cylinder pressure exported from the gas power source FMU model with the piston rod velocity and displacement of the multibody dynamics model of the linkage mechanism according to the preset input-output correspondence. S6. Set the co-simulation conditions and perform co-simulation. Based on the given gas power source FMU model parameters, calculate the dynamic characteristics of the pneumatic linkage mechanism during the entire process of erection and retraction, as well as the force conditions of each link at any time.

2. The pneumatic linkage co-simulation method based on the FMI standard according to claim 1, characterized in that: The gas power source model uses carbon dioxide as the working fluid.

3. The pneumatic linkage co-simulation method based on the FMI standard according to claim 1, characterized in that: The coupling relationship between the gas power source model and the multibody dynamics model of the linkage mechanism during co-simulation is as follows: Gas power source model: in These are the piston rod thrust and the pressure on both sides of the cylinder calculated by the gas power source model at time n+1, respectively. These are the piston rod velocity and piston rod displacement calculated for the linkage mechanism model at time n, respectively. Multibody dynamics model of linkage mechanism: in These represent the piston rod velocity and piston rod displacement calculated for the linkage mechanism model at time n+1, respectively. These are the piston rod thrust and the pressure on both sides of the cylinder calculated by the gas power source model at time n, respectively.

4. An electronic device, characterized in that: Including processor and memory; The memory is used to store programs; The processor executes the program to implement the method as described in claim 1.

5. A computer-readable storage medium, characterized in that: The storage medium stores a program that is executed by a processor to implement the method as described in claim 1.

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