Air spring modeling method, device, equipment, storage medium and program product

Abstract

The invention relates to the technical field of vehicle simulation, and discloses an air spring modeling method, device and equipment, a storage medium and a program product, and the method comprises the steps: obtaining the structure parameters of an air spring; based on the structural parameters, determining a target airbag volume variation of the air spring; based on the structure parameters, a preset gas law and a preset thermodynamic law, the air pressure change rate and the temperature change rate of the air spring are determined; and modeling the air spring according to the volume variation, the air pressure change rate and the temperature change rate of the target air bag. According to the method, the target air bag volume variable quantity of the air spring is determined, and the air pressure change rate and the temperature change rate in the deformation process are considered, so that the modeling accuracy and the simulation precision of the air spring are improved, and the prediction error is reduced; depending on suppliers is not needed, the development efficiency of vehicle dynamics simulation is improved, introduction of human factors is reduced, and the model accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle simulation, and in particular to an air spring modeling method, device, equipment, storage medium and program product. Background Art

[0002] When simulating air springs in vehicle dynamics, the relationship curve between the deformation and force of the air spring under three different initial inflation pressures is usually used to describe the elastic characteristics of the air spring.

[0003] At present, the above three relationship curves are generally output to vehicle manufacturers by suppliers after model calculation and experimental testing. In other words, when performing vehicle dynamics simulation, vehicle manufacturers are very dependent on the air spring elastic characteristic curves provided by suppliers, which greatly affects development efficiency. In addition, according to the theoretical knowledge of aerodynamics and heat transfer, heat will be generated inside the air spring during the deformation process, and there will be heat exchange between the inside and the outside, and the heat exchange capacity at different operating frequencies is also different. The elastic characteristics of the air spring have frequency correlation and hysteresis characteristics, and the current air spring elastic characteristic curves do not take these characteristics into account, resulting in large errors between the vehicle dynamics simulation results and the test results.

[0004] Therefore, how to solve the low development efficiency and low simulation accuracy caused by the traditional technology using the air spring elastic characteristic curve provided by the supplier has become a key issue that needs to be solved urgently. Summary of the invention

[0005] In view of this, the present invention provides an air spring modeling method, device, equipment, storage medium and program product to solve the problem that the traditional method uses the air spring elastic characteristic curve provided by the supplier, resulting in low development efficiency and low simulation accuracy.

[0006] In a first aspect, the present invention provides an air spring modeling method, the method comprising:

[0007] Obtain the structural parameters of the air spring;

[0008] Based on the structural parameters, determining the target airbag volume change of the air spring;

[0009] Determine the air pressure change rate and temperature change rate of the air spring based on the structural parameters, the preset gas law and the preset thermodynamic law;

[0010] The air spring is modeled based on the target airbag volume change, air pressure change rate, and temperature change rate.

[0011] Beneficial effects: Based on the structural parameters of the air spring, the preset gas law and the preset thermodynamic law, the target airbag volume change of the air spring is determined, and the pressure change rate and temperature change rate of the air spring during the deformation process are considered, thereby improving the accuracy of air spring modeling and simulation accuracy and reducing prediction errors. In addition, there is no need to rely on suppliers, which improves the development efficiency of vehicle dynamics simulation, reduces the introduction of human factors, and improves model accuracy.

[0012] In an optional embodiment, the air spring is provided with a variable cross-section piston, and the structural parameters include the displacement of the variable cross-section piston, the structural parameters of the variable cross-section piston, the theoretical value of the displacement of the cylindrical piston, and the structural parameters of the cylindrical piston; based on the structural parameters, determining the target airbag volume change of the air spring includes:

[0013] Based on the displacement theoretical value of the cylindrical piston and the structural parameters of the cylindrical piston, determining the volume change of the first airbag caused by the displacement movement of the cylindrical piston;

[0014] The current value of the displacement of the variable-section piston is set as the theoretical value of the displacement of the cylindrical piston, and the volume change of the second airbag caused by the displacement movement of the variable-section piston is determined according to the structural parameters of the variable-section piston;

[0015] Calculating a conversion coefficient according to a proportional relationship between a volume change of the first airbag and a volume change of the second airbag;

[0016] The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable-section piston displacement and the cylindrical piston structural parameters.

[0017] Beneficial effect: first determine the volume change of the first airbag caused by the displacement movement of the cylindrical piston and the volume change of the second airbag caused by the displacement movement of the variable-section piston, equate the variable-section piston to a cylindrical piston, and obtain a conversion coefficient based on the ratio between the volume change of the first airbag and the volume change of the second airbag, so as to obtain the volume change of any variable-section piston empty spring equivalent to a cylindrical piston empty spring.

[0018] In an optional implementation, the cylindrical piston structural parameters include a cylindrical piston rod diameter and a cylindrical piston diameter; based on the cylindrical piston displacement theoretical value and the cylindrical piston structural parameters, determining the volume change of the first airbag caused by the displacement movement of the cylindrical piston includes:

[0019] Calculate the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter;

[0020] The volume change of the first airbag caused by the displacement movement of the cylindrical piston is calculated based on the product of the square difference, the theoretical value of the cylindrical piston displacement and the preset volume calculation coefficient.

[0021] Beneficial effect: The volume change of the first airbag is calculated by using parameters such as the cylindrical piston diameter, the cylindrical piston rod diameter and the cylindrical piston displacement theoretical value, so as to accurately obtain the volume change of the airbag of the air spring caused by the cylindrical piston displacement at a certain moment.

[0022] In an optional implementation, the variable cross-section piston structural parameters include the variable cross-section piston diameter; and determining the volume change of the second airbag caused by the displacement movement of the variable cross-section piston according to the variable cross-section piston structural parameters includes:

[0023] The volume change of the second airbag caused by the displacement movement of the variable cross-section piston is calculated based on the product of the square of the variable cross-section piston diameter, the current value of the variable cross-section piston displacement and the preset volume calculation coefficient.

[0024] Beneficial effect: By making the variable-section piston equivalent to a cylindrical piston, setting the current value of the variable-section piston displacement to the theoretical value of the cylindrical piston displacement, and accurately measuring the volume change of the second airbag caused by the displacement movement of the variable-section piston according to the diameter of the variable-section piston, the calculation complexity is reduced.

[0025] In an optional implementation, the target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable cross-section piston displacement, and the cylindrical piston structural parameters, including:

[0026] Calculate the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter;

[0027] The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable-section piston displacement, the product of the square difference and the preset volume calculation coefficient.

[0028] Beneficial effect: The target airbag volume change is calculated by the conversion coefficient and the actual value of the variable cross-section piston displacement, thereby obtaining the volume change of any variable cross-section piston empty spring equivalent to a cylindrical piston empty spring.

[0029] In an optional embodiment, based on the structural parameters, the preset gas law and the preset thermodynamic law, the air pressure change rate and the temperature change rate of the air spring are determined, including:

[0030] Based on the structural parameters and in accordance with the polytropic gas law and the ideal gas law, the air pressure differential equation corresponding to the air spring is determined;

[0031] The air pressure change rate and temperature change rate of the air spring are determined based on the structural parameters, the air pressure differential equation and the first law of thermodynamics.

[0032] Beneficial effect: By determining the air pressure change rate and temperature change rate of the air spring, the change characteristics of the air spring stiffness at different movement frequencies can be better described, and the hysteresis characteristics of the air spring can also be reflected.

[0033] In an optional embodiment, the structural parameters include gas volume and gas pressure; based on the structural parameters and in accordance with the polytropic gas law and the ideal gas law, the gas pressure differential equation corresponding to the air spring is determined, including:

[0034] A first expression is obtained based on the polytropic gas law, wherein the first expression is used to characterize that the product between the first power of the gas volume and the gas pressure is a first constant, and the first power is the gas polytropic index;

[0035] Based on the ideal gas law and the first expression, a second expression is calculated; wherein the ideal gas law is used to characterize that the product of gas pressure and gas volume diameter is equal to the amount of gas substance, the product of the molar gas constant and the temperature; the second expression is used to characterize that the product of the second power of gas pressure and the first power of temperature is the second constant, and the second power is calculated based on the gas polytropic index;

[0036] Differentiating the second expression, we obtain the first differential equation of air temperature with respect to air pressure;

[0037] Based on the first differential equation and the ideal gas law, the air pressure differential equation corresponding to the air spring is calculated.

[0038] Beneficial effect: Combining thermodynamic effects, according to the polytropic gas law and the ideal gas law, the air pressure differential equation corresponding to the air spring is calculated, so as to consider the air pressure change of the air spring during the deformation process, which is convenient for improving the modeling accuracy.

[0039] In an optional implementation, the air pressure change rate and the temperature change rate of the air spring are determined according to the structural parameters, the air pressure differential equation and the first law of thermodynamics, including:

[0040] Based on the structural parameters and the first law of thermodynamics, the internal energy change rate of the air spring is determined, and the corresponding balance equation of the air spring is constructed; the balance equation includes the mass balance equation and the enthalpy balance equation, and the parameters of the mass balance equation and the enthalpy balance equation include the air pressure change rate and the temperature change rate;

[0041] According to the internal energy change rate and the air pressure differential equation, the mass balance equation and the enthalpy balance equation are solved to obtain the air pressure change rate and temperature change rate of the air spring.

[0042] Beneficial effect: By constructing the mass balance equation and enthalpy balance equation corresponding to the air spring and solving the mass balance equation and enthalpy balance equation according to the internal energy change rate and the air pressure differential equation, the air pressure change rate and temperature change rate of the air spring are obtained, thereby measuring the air pressure change and temperature change of the air spring during the deformation process.

[0043] In an optional implementation, the air spring is modeled according to the target airbag volume change, air pressure change rate, and temperature change rate, including:

[0044] Determine the power bond diagram of the air spring according to the target airbag volume change, air pressure change rate and temperature change rate;

[0045] The force of the air spring is determined according to the power bond diagram, and the target air spring model is obtained.

[0046] Beneficial effects: By modeling the target airbag volume change, air pressure change rate and temperature change rate, the frequency correlation and hysteresis characteristics of the air spring elastic characteristics can be more accurately described, and the accuracy and prediction accuracy of the target air spring model can be improved.

[0047] In a second aspect, the present invention provides an air spring modeling device, the device comprising:

[0048] An acquisition module, used for acquiring structural parameters of the air spring;

[0049] A first processing module, configured to determine a target airbag volume change of the air spring based on the structural parameters;

[0050] A second processing module, for determining a pressure change rate and a temperature change rate of the air spring based on the structural parameters, a preset gas law and a preset thermodynamic law;

[0051] The third processing module is used to model the air spring according to the target airbag volume change, air pressure change rate and temperature change rate.

[0052] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the air spring modeling method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0053] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the air spring modeling method of the first aspect or any corresponding embodiment thereof.

[0054] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the air spring modeling method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 is a curve diagram of the relationship between deformation and force of an air spring according to an embodiment of the present invention;

[0057] Figure 2 is a schematic flow chart of an air spring modeling method according to an embodiment of the present invention;

[0058] Figure 3 is a schematic structural diagram of an air spring according to an embodiment of the present invention;

[0059] Figure 4 is a flow chart of another air spring modeling method according to an embodiment of the present invention;

[0060] Figure 5 is a power bonding diagram of an air spring according to an embodiment of the present invention;

[0061] Figure 6 is a schematic diagram of an iterative process for designing air spring stiffness according to an embodiment of the present invention;

[0062] Figure 7 is a schematic diagram of a test simulation comparison result according to an embodiment of the present invention;

[0063] Figure 8 is a comparison diagram of an air spring modeling method according to an embodiment of the present invention;

[0064] Fig. 9 is a structural block diagram of an air spring modeling device according to an embodiment of the present invention;

[0065] Fig.10 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0067] At present, the air springs used in vehicle dynamics simulation are usually Figure 1 The three curves shown are used to describe its elastic characteristics. For the convenience of description, this article calls it a three-dimensional interpolation model.

[0068] Figure 1 The figure shows the relationship between the deformation and force of the air spring under three different initial inflation pressures (corresponding to the moment of zero deformation). In traditional vehicle dynamics simulation, the software uses these three curves to build a three-dimensional surface, and uses a variable (real-time deformation of the air spring) and a parameter (force under the initial inflation pressure) to perform AKIMA interpolation calculation on the three-dimensional surface to obtain the third-dimensional force, and simulates the air spring based on the third-dimensional force.

[0069] However, Figure 1 There are two main ways to obtain the three curves shown: one is that the air spring supplier builds a finite element model of the air spring and calculates and outputs it to the vehicle manufacturer; the other is that the air spring supplier conducts a test on the actual air spring and outputs it to the vehicle manufacturer. Obviously, the use of a three-dimensional interpolation model to describe the elastic characteristics of the air spring is very dependent on the supplier.

[0070] In the past, vehicle manufacturers usually artificially specified a static frequency and a dynamic frequency, and then the air spring supplier conducted tests (or finite element analysis) to obtain three-dimensional interpolation models at two different frequencies. The vehicle manufacturer then selected a three-dimensional interpolation model of one frequency according to the working conditions to simulate vehicle dynamics. When other working conditions need to be simulated, the three-dimensional interpolation model must be switched synchronously. In the above test and simulation process, human factors will inevitably increase, affecting the accuracy and low efficiency.

[0071] In addition, according to the theoretical knowledge of aerodynamics and heat transfer, heat will be generated inside the air spring during the deformation process, and there will be heat exchange between the inside and the outside, and the heat exchange capacity will be different at different operating frequencies. In other words, the elastic characteristics of the air spring have frequency correlation and hysteresis characteristics. In actual use, the operating frequency of the air spring changes almost all the time. Even in a standard test condition, it basically does not work at a fixed frequency. The three-dimensional interpolation model used in the past cannot accurately describe the frequency correlation and hysteresis characteristics of the air spring, resulting in a large error between the vehicle dynamics simulation results and the test results, resulting in low simulation accuracy and poor prediction ability.

[0072] Therefore, an embodiment of the present invention provides an air spring modeling solution for vehicle dynamics simulation. Compared with the air spring modeling method traditionally used in the automotive industry, it has higher accuracy, eliminates human factors to a large extent, improves the accuracy of vehicle dynamics simulation, and can reduce dependence on suppliers in the early design stage, and can output the main characteristic parameters of the air spring.

[0073] According to an embodiment of the present invention, an embodiment of an air spring modeling method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0074] In this embodiment, an air spring modeling method is provided, which can be used for a computer device or terminal, such as a computer, a tablet computer, etc., to model an air spring. Figure 2 is a flow chart of an air spring modeling method according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0075] Step S201, obtaining structural parameters of the air spring.

[0076] Specifically, an air spring is generally provided with a variable cross-section piston. The change in airbag volume caused by the displacement movement of the variable cross-section piston is difficult to directly calculate based on existing parameters. Therefore, the variable cross-section piston can be equivalent to a cylindrical piston to facilitate the calculation of the change in airbag volume of the air spring.

[0077] Specifically, the structural parameters of the air spring mainly include the displacement of the variable-section piston, the structural parameters of the variable-section piston, the theoretical value of the displacement of the cylindrical piston, the structural parameters of the cylindrical piston, the gas volume and the gas pressure, among which the structural parameters of the variable-section piston include the diameter of the variable-section piston. Figure 3As shown, an embodiment of the present invention provides a structural schematic diagram of an air spring, which includes a cylindrical piston, and the structural parameters of the cylindrical piston include parameters such as the cylindrical piston rod diameter dr, the cylindrical piston diameter dp and the airbag wall diameter da.

[0078] Step S202: determining a target airbag volume change of the air spring based on the structural parameters.

[0079] Specifically, since the piston of the air spring has a variable cross-section, it is difficult to directly calculate the volume change of the airbag caused by the displacement of the cylindrical piston at a certain moment based on the structural parameters of the variable cross-section piston. Therefore, we can first calculate the volume change of the airbag caused by the displacement of the cylindrical piston at a certain moment, and then equate the variable cross-section piston to a cylindrical piston. Calculate the volume change corresponding to the equivalent of any variable cross-section piston empty spring to the cylindrical piston empty spring, and finally obtain the target airbag volume change of the air spring.

[0080] Step S203, determining the air pressure change rate and temperature change rate of the air spring based on the structural parameters, the preset gas law and the preset thermodynamic law.

[0081] Specifically, since heat will be generated inside the air spring during the deformation process and there is heat exchange between the inside and the outside, the air pressure change rate and temperature change rate of the air spring must be obtained based on thermodynamics and heat transfer, and the frequency correlation and hysteresis characteristics of the air spring must be considered in order to better describe its elastic characteristics.

[0082] Step S204, modeling the air spring according to the target airbag volume change, air pressure change rate and temperature change rate.

[0083] Specifically, according to the target airbag volume change during the deformation process of the air spring, the air pressure change and temperature change inside the air spring are considered at the same time, so as to improve the modeling accuracy and simulation precision.

[0084] The air spring modeling method provided in this embodiment determines the target airbag volume change of the air spring based on the structural parameters of the air spring, the preset gas law and the preset thermodynamic law, and takes into account the pressure change rate and temperature change rate of the air spring during the deformation process, thereby improving the accuracy of air spring modeling and simulation accuracy and reducing prediction errors. In addition, there is no need to rely on suppliers, which improves the development efficiency of vehicle dynamics simulation, reduces the introduction of human factors, and improves model accuracy.

[0085] In this embodiment, an air spring modeling method is provided, which can be used for a computer device or terminal, such as a computer, a tablet computer, etc., to model an air spring. Figure 4 is a flow chart of an air spring modeling method according to an embodiment of the present invention. Figure 4 As shown, the process includes the following steps:

[0086] Step S401, obtain the structural parameters of the air spring. For details, please refer to Figure 2 Step S201 of the illustrated embodiment will not be described in detail here.

[0087] Step S402: determining a target airbag volume change of the air spring based on the structural parameters.

[0088] Specifically, the air spring is provided with a variable cross-section piston, and the structural parameters include the displacement of the variable cross-section piston, the structural parameters of the variable cross-section piston, the theoretical value of the displacement of the cylindrical piston, and the structural parameters of the cylindrical piston. The above step S402 includes:

[0089] Step S4021, based on the cylindrical piston displacement theoretical value and the cylindrical piston structural parameters, determine the first airbag volume change caused by the displacement movement of the cylindrical piston.

[0090] In some optional embodiments, the cylindrical piston structural parameters include the cylindrical piston rod diameter and the cylindrical piston diameter, and the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter is first calculated. Then, the volume change of the first airbag caused by the displacement of the cylindrical piston is calculated based on the product of the square difference, the theoretical value of the cylindrical piston displacement and the preset volume calculation coefficient, so as to obtain the volume change of the airbag caused by the displacement of the cylindrical piston at a certain moment.

[0091] Exemplarily, the volume change of the first airbag may be calculated according to the following formula:

[0092]

[0093] Among them, vol1 represents the change in the volume of the first airbag, length1 represents the theoretical displacement value of the cylindrical piston, dp represents the diameter of the cylindrical piston, and dr represents the diameter of the cylindrical piston rod. Calculates the coefficient for the preset volume.

[0094] This embodiment calculates the volume change of the first airbag through parameters such as the cylindrical piston diameter, the cylindrical piston rod diameter and the cylindrical piston displacement theoretical value, so as to accurately obtain the volume change of the airbag of the air spring caused by the cylindrical piston displacement at a certain moment.

[0095] Step S4022, setting the current value of the variable cross-section piston displacement as the theoretical value of the cylindrical piston displacement, and determining the volume change of the second airbag caused by the displacement movement of the variable cross-section piston according to the variable cross-section piston structural parameters.

[0096] In some optional embodiments, the variable cross-section piston structural parameters include the variable cross-section piston diameter, and the volume change of the second airbag caused by the displacement movement of the variable cross-section piston is calculated based on the product of the square of the variable cross-section piston diameter, the current value of the variable cross-section piston displacement and a preset volume calculation coefficient.

[0097] For example, assuming that the diameter of the circular cross-section of the variable cross-section piston at a certain moment is dy, the volume change of the second airbag can be calculated according to the following formula:

[0098]

[0099] Among them, vol2 represents the change in volume of the second airbag, and length2 represents the displacement of the variable-section piston.

[0100] This embodiment reduces the calculation complexity by making the variable-section piston equivalent to a cylindrical piston, setting the current value of the variable-section piston displacement to the theoretical value of the cylindrical piston displacement, and accurately measuring the change in the volume of the second airbag caused by the displacement movement of the variable-section piston based on the diameter of the variable-section piston.

[0101] Step S4023, calculating a conversion coefficient according to the proportional relationship between the first airbag volume change and the second airbag volume change.

[0102] Specifically, let the conversion coefficient k1 make vol1=k1×vol2, then:

[0103]

[0104] Moreover, the above step S4022 has set the current value of the displacement of the variable cross-section piston to the theoretical value of the displacement of the cylindrical piston, that is, let length2=length1. That is, according to the ratio between the volume change of the first airbag and the volume change of the second airbag, we can obtain:

[0105]

[0106] This embodiment measures the conversion relationship between the volume changes caused by the cylindrical piston and the variable-section piston through the proportional relationship between the first airbag volume change and the second airbag volume change, so as to directly calculate the airbag volume change using the obtained conversion coefficient and the directly measurable parameters.

[0107] Step S4024, calculating the target airbag volume change of the air spring according to the conversion coefficient, the actual value of the variable cross-section piston displacement and the cylindrical piston structural parameters.

[0108] In some optional embodiments, the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter is calculated, and then the target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable-section piston displacement, the product of the square difference and the preset volume calculation coefficient.

[0109] Exemplarily, the target airbag volume change may be calculated according to the following formula:

[0110]

[0111] Wherein, vol represents the change in target airbag volume.

[0112] This embodiment calculates the target airbag volume change through the conversion coefficient and the actual value of the variable cross-section piston displacement, thereby obtaining the volume change of any variable cross-section piston empty spring equivalent to a cylindrical piston empty spring.

[0113] In an embodiment of the present application, the volume change of the first airbag caused by the displacement movement of the cylindrical piston and the volume change of the second airbag caused by the displacement movement of the variable-section piston are first determined, and the variable-section piston is equivalent to a cylindrical piston. A conversion coefficient is obtained according to the ratio between the first airbag volume change and the second airbag volume change, so as to obtain the volume change of any variable-section piston empty spring equivalent to a cylindrical piston empty spring.

[0114] Step S403, determining the air pressure change rate and temperature change rate of the air spring based on the structural parameters, the preset gas law and the preset thermodynamic law.

[0115] Specifically, the above step S403 includes:

[0116] Step S4031, based on the structural parameters and in accordance with the polytropic gas law and the ideal gas law, determine the air pressure differential equation corresponding to the air spring.

[0117] In some optional implementations, the above step S4031 includes:

[0118] Step a1, obtaining a first expression based on the polytropic gas law, the first expression is used to characterize that the product between the first power of the gas volume and the gas pressure is a first constant, and the first power is the gas polytropic index.

[0119] Exemplarily, the thermodynamic effect is simplified to the polytropic gas law, and the first expression is obtained:

[0120] P.V. k2 =constant1

[0121] Wherein, P represents gas pressure, V represents gas volume, k2 represents gas polynomial index, and constant1 represents the first constant.

[0122] Step a2, based on the ideal gas law and the first expression, calculate the second expression. The ideal gas law is used to characterize that the product of gas pressure and gas volume diameter is equal to the amount of gas substance, the product of the molar gas constant and the temperature, and the second expression is used to characterize that the product of the second power of gas pressure and the first power of temperature is the second constant, and the second power is calculated based on the gas polytropic index.

[0123] Specifically, the ideal gas law can be expressed as:

[0124] P·V=n·r·T

[0125] Where n represents the amount of gas, r represents the molar gas constant, and T represents the temperature.

[0126] Furthermore, substituting the ideal gas law into the first expression, we can get the second expression:

[0127] P 1-k2 ·T k2 =constant2

[0128] Here, constant2 represents the second constant.

[0129] Step a3, differentiating the second expression to obtain a first differential equation of air temperature with respect to air pressure.

[0130] Exemplarily, the first differential equation can be expressed as:

[0131]

[0132] Step a4, performing differentiation based on the first differential equation and the ideal gas law, and calculating the air pressure differential equation corresponding to the air spring.

[0133] Specifically, the ideal gas law is differentiated and substituted into the first differential equation above to obtain the pressure differential equation:

[0134]

[0135] In an embodiment of the present application, the air pressure differential equation corresponding to the air spring is calculated based on the polytropic gas law and the ideal gas law in combination with the thermodynamic effect, thereby taking into account the air pressure changes of the air spring during the deformation process, thereby facilitating improving the modeling accuracy.

[0136] Step S4032, determining the air pressure change rate and temperature change rate of the air spring according to the structural parameters, the air pressure differential equation and the first law of thermodynamics.

[0137] Specifically, firstly, based on the structural parameters and the first law of thermodynamics, the internal energy change rate of the air spring is determined, and the corresponding balance equation of the air spring is constructed. The balance equation includes the mass balance equation and the enthalpy balance equation. The parameters of the mass balance equation and the enthalpy balance equation include the air pressure change rate and the temperature change rate. Then, according to the internal energy change rate and the air pressure differential equation, the mass balance equation and the enthalpy balance equation are solved to obtain the air pressure change rate and the temperature change rate of the air spring.

[0138] For example, considering the thermodynamic effect, applying the first law of thermodynamics, the internal energy change rate equation related to the internal energy U is introduced:

[0139]

[0140] in, represents the rate of change of internal energy, represents the heat flow rate at the input end, is the heat flux through the effective volume, Indicates the work pressure.

[0141] It should be noted that the work pressure It can be expressed as:

[0142]

[0143] in, Indicates the volume change.

[0144] Furthermore, the mass units related to internal energy are introduced as follows:

[0145] U=m·u

[0146] Where m represents the internal energy of the unit mass.

[0147] Furthermore, substituting U = m·u into the above internal energy change rate equation, we have:

[0148]

[0149] Then, according to parameters such as work pressure, we have:

[0150]

[0151] Among them, c v Represents specific heat at constant volume.

[0152] Finally, according to the differential equation of air pressure and internal energy, by solving the equations of mass balance and enthalpy balance as follows, the derivatives of the temperature and pressure of the pressure vessel with respect to time, that is, the temperature change rate, can be obtained and the rate of change of air pressure

[0153]

[0154] In an embodiment of the present application, by constructing the mass balance equation and enthalpy balance equation corresponding to the air spring, and solving the mass balance equation and enthalpy balance equation according to the internal energy change rate and the air pressure differential equation, the air pressure change rate and temperature change rate of the air spring are obtained, thereby measuring the air pressure change and temperature change of the air spring during the deformation process.

[0155] Step S404, modeling the air spring according to the target airbag volume change, air pressure change rate and temperature change rate.

[0156] Specifically, the above step S404 includes:

[0157] S4041, determining a power bonding diagram of the air spring according to the target airbag volume change, air pressure change rate, and temperature change rate.

[0158] Specifically, Figure 5 As shown, considering the air pressure change rate and temperature change rate of the air spring, a power bonding graph capable of calculating the thermodynamic effect is constructed. At the same time, according to the target airbag volume change, a power bonding graph capable of calculating the airbag pressure and volume is constructed.

[0159] S4042, determining the force of the air spring according to the power bonding diagram, and obtaining a target air spring model.

[0160] Specifically, according to Figure 5 The power bond diagram shown calculates the force of the air spring, thereby modeling the target air spring model.

[0161] In some optional implementations, in addition to using power bond graph modeling software, the air spring model can also be established by using mathematical calculation software such as MATLAB to solve the results of the air spring properties using the formulas listed in the embodiments of the present invention and perform a joint simulation with the vehicle dynamics model.

[0162] This embodiment uses the target airbag volume change, air pressure change rate and temperature change rate to build a model, which more accurately describes the frequency correlation and hysteresis characteristics of the air spring elastic characteristics, thereby improving the accuracy and prediction accuracy of the target air spring model.

[0163] In the embodiments of the present application, starting from the gas state equation and the principle of heat transfer, by calculating the equivalent volume change of the piston during the deformation of the air spring, and introducing the formulas of gas mass balance and enthalpy balance, the air pressure change inside the air spring is calculated, and finally the force generated by the air spring is calculated, thereby improving the accuracy of air spring modeling.

[0164] Compared with the air spring modeling method used in traditional vehicle dynamics, the present invention has the following significant advantages:

[0165] 1) Improved agility of vehicle dynamics simulation: The present invention does not require suppliers to provide elastic characteristic curves of air springs to establish a three-dimensional interpolation model, reducing dependence on suppliers. The present invention only requires the engineering department to provide basic dimensional parameters such as the outer diameter of the air spring and the cross-section of the piston to calculate the elastic characteristics of the air spring. Figure 6As shown, the present invention can also provide optimized air spring structural parameters for engineering design iteration according to the simulation results.

[0166] 2) Directly using a set of simulation models for calculation, which is highly efficient: Different from the traditional vehicle dynamics simulation method that selects three-dimensional interpolation models of air springs with different frequencies according to different simulation conditions, the present invention only uses a set of air spring models in the whole vehicle simulation, which can adapt to various simulation conditions without manual judgment and switching.

[0167] 3) Taking into account the frequency correlation and hysteresis characteristics of the air spring stiffness, with good accuracy: Different from the traditional interpolation method, the present invention takes into account the changing characteristics of the air spring stiffness under different movement frequencies, and can also reflect the hysteresis characteristics of the air spring, with good accuracy. Figure 7 As shown, according to the air lift spring model of the present invention, simulation and testing are carried out, and it can be seen that the curve overlap rate of the simulation results and the test results is relatively high, that is, the model constructed by the present invention can well simulate the changing characteristics of the air spring stiffness.

[0168] like Figure 8 As shown, the present invention provides a comparison diagram with the traditional three-dimensional interpolation model for vehicle dynamics simulation. In summary, the present invention builds a suspension system model with air springs through power bond graph software, builds a whole vehicle dynamics model through multi-body dynamics software, and can customize the structural parameters of the air spring through the joint simulation method to get rid of the dependence on suppliers; and it can adapt to different working conditions without manually defining the working state of the air spring, reducing the interference of human factors, and at the same time eliminating the process of manually switching the three-dimensional interpolation model of the air spring; in addition, it can also more accurately describe the frequency correlation and hysteresis characteristics of the elastic characteristics of the air spring.

[0169] In this embodiment, an air spring modeling device is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0170] This embodiment provides an air spring modeling device, such as Fig. 9 As shown, including:

[0171] An acquisition module 901 is used to acquire structural parameters of the air spring;

[0172] A first processing module 902 is used to determine a target airbag volume change of the air spring based on the structural parameters;

[0173] A second processing module 903 is used to determine the air pressure change rate and the temperature change rate of the air spring based on the structural parameters, the preset gas law and the preset thermodynamic law;

[0174] The third processing module 904 is used to model the air spring according to the target airbag volume change, air pressure change rate and temperature change rate.

[0175] In some optional implementations, the air spring is provided with a variable cross-section piston, and the structural parameters include variable cross-section piston displacement, variable cross-section piston structural parameters, cylindrical piston displacement theoretical value and cylindrical piston structural parameters; the first processing module 902 is further used for:

[0176] Based on the displacement theoretical value of the cylindrical piston and the structural parameters of the cylindrical piston, determining the volume change of the first airbag caused by the displacement movement of the cylindrical piston;

[0177] The current value of the displacement of the variable-section piston is set as the theoretical value of the displacement of the cylindrical piston, and the volume change of the second airbag caused by the displacement movement of the variable-section piston is determined according to the structural parameters of the variable-section piston;

[0178] Calculating a conversion coefficient according to a proportional relationship between a volume change of the first airbag and a volume change of the second airbag;

[0179] The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable-section piston displacement and the cylindrical piston structural parameters.

[0180] In some optional implementations, the cylindrical piston structural parameters include a cylindrical piston rod diameter and a cylindrical piston diameter; the first processing module 902 is further used for:

[0181] Calculate the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter;

[0182] The volume change of the first airbag caused by the displacement movement of the cylindrical piston is calculated based on the product of the square difference, the theoretical value of the cylindrical piston displacement and the preset volume calculation coefficient.

[0183] In some optional implementations, the variable cross-section piston structural parameter includes the variable cross-section piston diameter; the first processing module 902 is further used for:

[0184] The volume change of the second airbag caused by the displacement movement of the variable cross-section piston is calculated based on the product of the square of the variable cross-section piston diameter, the current value of the variable cross-section piston displacement and the preset volume calculation coefficient.

[0185] In some optional implementations, the first processing module 902 is further configured to:

[0186] Calculate the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter;

[0187] The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable-section piston displacement, the product of the square difference and the preset volume calculation coefficient.

[0188] In some optional implementations, the second processing module 903 is further configured to:

[0189] Based on the structural parameters and in accordance with the polytropic gas law and the ideal gas law, the air pressure differential equation corresponding to the air spring is determined;

[0190] The air pressure change rate and temperature change rate of the air spring are determined based on the structural parameters, the air pressure differential equation and the first law of thermodynamics.

[0191] In some optional implementations, the structural parameters include gas volume and gas pressure; the second processing module 903 is further used for:

[0192] A first expression is obtained based on the polytropic gas law, wherein the first expression is used to characterize that the product between the first power of the gas volume and the gas pressure is a first constant, and the first power is the gas polytropic index;

[0193] Based on the ideal gas law and the first expression, a second expression is calculated; wherein the ideal gas law is used to characterize that the product of gas pressure and gas volume diameter is equal to the amount of gas substance, the product of the molar gas constant and the temperature; the second expression is used to characterize that the product of the second power of gas pressure and the first power of temperature is the second constant, and the second power is calculated based on the gas polytropic index;

[0194] Differentiating the second expression, we obtain the first differential equation of air temperature with respect to air pressure;

[0195] Based on the first differential equation and the ideal gas law, the air pressure differential equation corresponding to the air spring is calculated.

[0196] In some optional implementations, the second processing module 903 is further configured to:

[0197] Based on the structural parameters and the first law of thermodynamics, the internal energy change rate of the air spring is determined, and the corresponding balance equation of the air spring is constructed; the balance equation includes the mass balance equation and the enthalpy balance equation, and the parameters of the mass balance equation and the enthalpy balance equation include the air pressure change rate and the temperature change rate;

[0198] According to the internal energy change rate and the air pressure differential equation, the mass balance equation and the enthalpy balance equation are solved to obtain the air pressure change rate and temperature change rate of the air spring.

[0199] In some optional implementations, the third processing module 904 is further configured to:

[0200] Determine the power bond diagram of the air spring according to the target airbag volume change, air pressure change rate and temperature change rate;

[0201] The force of the air spring is determined according to the power bond diagram, and the target air spring model is obtained.

[0202] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0203] The air spring modeling device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0204] The embodiment of the present invention also provides a computer device having the above Fig. 9 The air spring modeling device shown.

[0205] See also Fig.10 , Fig.10 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig.10 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.10 A processor 10 is taken as an example.

[0206] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0207] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0208] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0209] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0210] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Fig.10 The example of connecting through bus is taken in the following.

[0211] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0212] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0213] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0214] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for modeling an air spring, characterized in that: The method comprises: Obtain the structural parameters of the air spring; Based on the structural parameters, determining a target airbag volume change of the air spring; Determining the air pressure change rate and the temperature change rate of the air spring based on the structural parameters, the preset gas law and the preset thermodynamic law; The air spring is modeled according to the target airbag volume change, the air pressure change rate, and the temperature change rate.

2. The method according to claim 1, characterized in that The air spring is provided with a variable cross-section piston, and the structural parameters include displacement of the variable cross-section piston, structural parameters of the variable cross-section piston, theoretical displacement value of the cylindrical piston, and structural parameters of the cylindrical piston; based on the structural parameters, determining the target airbag volume change of the air spring includes: Based on the cylindrical piston displacement theoretical value and the cylindrical piston structural parameters, determining the volume change of the first airbag caused by the displacement movement of the cylindrical piston; The current value of the displacement of the variable-section piston is set as the theoretical value of the displacement of the cylindrical piston, and the volume change of the second airbag caused by the displacement movement of the variable-section piston is determined according to the structural parameters of the variable-section piston; Calculating a conversion coefficient according to a proportional relationship between the first airbag volume change and the second airbag volume change; The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable cross-section piston displacement and the cylindrical piston structural parameters.

3. The method according to claim 2, characterized in that The cylindrical piston structural parameters include a cylindrical piston rod diameter and a cylindrical piston diameter; the determining of the first airbag volume change caused by the displacement movement of the cylindrical piston based on the cylindrical piston displacement theoretical value and the cylindrical piston structural parameters includes: Calculating the square difference between the diameter of the cylindrical piston and the diameter of the cylindrical piston rod; The volume change of the first airbag caused by the displacement movement of the cylindrical piston is calculated based on the product of the square difference, the theoretical value of the cylindrical piston displacement and the preset volume calculation coefficient.

4. The method according to claim 2, characterized in that: The variable cross-section piston structural parameters include the diameter of the variable cross-section piston; and determining the volume change of the second airbag caused by the displacement movement of the variable cross-section piston according to the variable cross-section piston structural parameters includes: The volume change of the second airbag caused by the displacement movement of the variable cross-section piston is calculated based on the product of the square of the diameter of the variable cross-section piston, the current value of the displacement of the variable cross-section piston and a preset volume calculation coefficient.

5. The method according to claim 3, characterized in that: The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable cross-section piston displacement and the cylindrical piston structural parameters, including: Calculating the square difference between the diameter of the cylindrical piston and the diameter of the cylindrical piston rod; The target airbag volume change of the air spring is calculated based on the conversion coefficient, the actual value of the variable-section piston displacement, the product of the square difference and a preset volume calculation coefficient.

6. The method according to claim 1, characterized in that The determining of the air pressure change rate and the temperature change rate of the air spring based on the structural parameters, the preset gas law and the preset thermodynamic law includes: Based on the structural parameters and in accordance with the polytropic gas law and the ideal gas law, a pressure differential equation corresponding to the air spring is determined; The air pressure change rate and the temperature change rate of the air spring are determined according to the structural parameters, the air pressure differential equation and the first law of thermodynamics.

7. The method according to claim 6, characterized in that The structural parameters include gas volume and gas pressure; the gas pressure differential equation corresponding to the air spring is determined based on the structural parameters and in accordance with the polytropic gas law and the ideal gas law, including: Obtaining a first expression based on the polytropic gas law, wherein the first expression is used to characterize that the product of the first power of the gas volume and the gas pressure is a first constant, and the first power is the gas polytropic index; Based on the ideal gas law and the first expression, a second expression is calculated; wherein the ideal gas law is used to characterize that the product of gas pressure and gas volume diameter is equal to the amount of gas substance, the product of the molar gas constant and the temperature; the second expression is used to characterize that the product of the second power of gas pressure and the first power of temperature is a second constant, and the second power is calculated based on the gas polytropic index; Differentiating the second expression to obtain a first differential equation of air temperature with respect to air pressure; Differentiation is performed based on the first differential equation and the ideal gas law to calculate and obtain an air pressure differential equation corresponding to the air spring.

8. The method according to claim 6 or 7, characterized in that: Determining the air pressure change rate and the temperature change rate of the air spring according to the structural parameters, the air pressure differential equation and the first law of thermodynamics includes: Based on the structural parameters and the first law of thermodynamics, the internal energy change rate of the air spring is determined, and a balance equation corresponding to the air spring is constructed; the balance equation includes a mass balance equation and an enthalpy balance equation, and the parameters of the mass balance equation and the enthalpy balance equation include an air pressure change rate and a temperature change rate; The mass balance equation and the enthalpy balance equation are solved according to the internal energy change rate and the air pressure differential equation to obtain the air pressure change rate and the temperature change rate of the air spring.

9. The method according to any one of claims 1 to 7, characterized in that: The step of modeling the air spring according to the target airbag volume change, the air pressure change rate, and the temperature change rate includes: Determining a power bonding diagram of the air spring according to the target airbag volume change, the air pressure change rate, and the temperature change rate; The force of the air spring is determined according to the power bond graph to obtain a target air spring model.

10. An air spring modeling device, characterized in that: The device comprises: An acquisition module, used for acquiring structural parameters of the air spring; A first processing module, configured to determine a target airbag volume change of the air spring based on the structural parameters; A second processing module, for determining a pressure change rate and a temperature change rate of the air spring based on the structural parameters, a preset gas law and a preset thermodynamic law; The third processing module is used to model the air spring according to the target airbag volume change, the air pressure change rate and the temperature change rate.

11. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the air spring modeling method according to any one of claims 1 to 9 by executing the computer instructions.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the air spring modeling method according to any one of claims 1 to 9.

13. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the air spring modeling method according to any one of claims 1 to 9.

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