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

Abstract

The application relates to the technical field of vehicle simulation, and discloses an air spring modeling method, device, equipment, storage medium and program product, which comprises the following steps: obtaining structural parameters of an air spring; determining a target air bag volume change amount of the air spring based on the structural parameters; determining an air 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; and modeling the air spring according to the target air bag volume change amount, the air pressure change rate and the temperature change rate. The application determines the target air bag volume change amount of the air spring, simultaneously considers the air pressure change rate and the temperature change rate in the deformation process, thereby improving the accuracy of air spring modeling and the simulation accuracy, reducing the prediction error, not needing to depend on a supplier, improving the development efficiency of vehicle dynamics simulation, reducing the introduction of human factors, and improving the model accuracy.

Description

TECHNICAL FIELD

[0001] The present application 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

[0002] In vehicle dynamics, the elastic properties of the air spring are usually described by using three different initial air pressure curves of the relationship between the air spring deformation and force.

[0003] At present, the above-mentioned three relationship curves are generally output to the vehicle enterprise by the supplier after model calculation and test test. That is, the vehicle enterprise is very dependent on the air spring elastic property curve provided by the supplier when performing vehicle dynamics simulation, which greatly affects the development efficiency. And according to the theoretical knowledge of aerodynamics and heat transfer, heat is generated inside the air spring during deformation, and there is heat exchange between the inside and the outside, and the heat exchange capacity is different under different working frequencies, and the elastic properties of the air spring have frequency correlation and hysteresis characteristics, but the current air spring elastic property curve does not consider these characteristics, resulting in a large error between the vehicle dynamics simulation result and the test result.

[0004] Therefore, how to solve the low development efficiency and low simulation accuracy caused by the traditional technology of using the air spring elastic property curve provided by the supplier has become a key problem to be solved. SUMMARY

[0005] Therefore, the present application provides an air spring modeling method, device, equipment, storage medium and program product to solve the problem of low development efficiency and low simulation accuracy caused by the traditional method of using the air spring elastic property curve provided by the supplier.

[0006] In a first aspect, the present application provides an air spring modeling method, which comprises:

[0007] obtaining the structure parameters of the air spring;

[0008] determining the target air bag volume change of the air spring based on the structure parameters;

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

[0010] modeling the air spring according to the target air bag volume change, the air pressure change rate and the 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 air bag volume change amount of the air spring is determined, and the air pressure change rate and the temperature change rate of the air spring in the deformation process are considered, thereby improving the accuracy of air spring modeling and the simulation accuracy, and reducing the prediction error. In addition, it does not need to rely on the supplier, improves the development efficiency of vehicle dynamics simulation, reduces the introduction of human factors, and improves the model accuracy.

[0012] In an optional embodiment, 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; based on the structural parameters, the target air bag volume change amount of the air spring is determined, including:

[0013] Based on the cylindrical piston displacement theoretical value and the cylindrical piston structural parameters, the first air bag volume change amount caused by the displacement movement of the cylindrical piston is determined;

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

[0015] According to the proportional relationship between the first air bag volume change amount and the second air bag volume change amount, a conversion coefficient is calculated;

[0016] According to the conversion coefficient, the actual value of the variable cross-section piston displacement and the cylindrical piston structural parameters, the target air bag volume change amount of the air spring is calculated.

[0017] Beneficial effects: first, the first air bag volume change amount caused by the displacement movement of the cylindrical piston and the second air bag volume change amount caused by the displacement movement of the variable cross-section piston are determined, and the variable cross-section piston is equivalent to the cylindrical piston. According to the ratio of the first air bag volume change amount and the second air bag volume change amount, a conversion coefficient is obtained to obtain the equivalent volume change of the variable cross-section piston air spring to the cylindrical piston air spring.

[0018] In an optional embodiment, the cylindrical piston structural parameters include cylindrical piston rod diameter and cylindrical piston diameter; based on the cylindrical piston displacement theoretical value and the cylindrical piston structural parameters, the first air bag volume change amount caused by the displacement movement of the cylindrical piston is determined, including:

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

[0020] According to the product of the square difference, the cylindrical piston displacement theoretical value and the preset volume calculation coefficient, the first air bag volume change amount caused by the displacement movement of the cylindrical piston is calculated.

[0021] Beneficial effects: the first air bag volume change amount is calculated through the cylinder piston diameter, the cylinder piston rod diameter and the cylinder piston displacement theoretical value, so that the volume change of the air spring caused by the cylinder piston displacement at a certain moment is accurately obtained.

[0022] In an alternative embodiment, the variable cross-section piston structure parameter comprises a variable cross-section piston diameter; and the second air bag volume change amount caused by the displacement movement of the variable cross-section piston is determined according to the variable cross-section piston structure parameter, comprising:

[0023] The second air bag volume change amount caused by the displacement movement of the variable cross-section piston is calculated according to the product between 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 effects: the variable cross-section piston is equivalent to a cylinder piston, the current value of the variable cross-section piston displacement is set as the cylinder piston displacement theoretical value, and the second air bag volume change amount caused by the displacement movement of the variable cross-section piston is accurately measured according to the variable cross-section piston diameter, so that the calculation complexity is reduced.

[0025] In an alternative embodiment, the target air bag volume change amount of the air spring is calculated according to the conversion coefficient, the actual value of the variable cross-section piston displacement and the cylinder piston structure parameter, comprising:

[0026] The square difference between the cylinder piston diameter and the cylinder piston rod diameter is calculated;

[0027] The target air bag volume change amount of the air spring is calculated according to the product between the conversion coefficient, the actual value of the variable cross-section piston displacement, the square difference and the preset volume calculation coefficient.

[0028] Beneficial effects: the target air bag volume change amount is calculated through the conversion coefficient and the actual value of the variable cross-section piston displacement, so that the volume change of the variable cross-section piston air spring equivalent to the cylinder piston air spring is obtained.

[0029] In an alternative embodiment, the air pressure change rate and the temperature change rate of the air spring are determined based on the structure parameter, the preset gas law and the preset thermodynamic law, comprising:

[0030] The air pressure differential equation corresponding to the air spring is determined based on the structure parameter and according to the polytropic gas law and the ideal gas law;

[0031] The air pressure change rate and the temperature change rate of the air spring are determined according to the structure parameter, the air pressure differential equation and the first law of thermodynamics.

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

[0033] In an optional implementation, the structure parameters include a gas volume and a gas pressure; based on the structure parameters, and according to a polytropic gas law and an ideal gas law, a corresponding gas pressure differential equation of the air spring is determined, including:

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

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

[0036] The second expression is differentiated to obtain a first differential equation of the gas temperature with respect to the gas pressure;

[0037] The first differential equation and the ideal gas law are differentiated to calculate the corresponding gas pressure differential equation of the air spring.

[0038] Beneficial effects: In combination with the thermodynamic effect, the corresponding gas pressure differential equation of the air spring is calculated according to the polytropic gas law and the ideal gas law, so that the gas pressure change of the air spring in the deformation process is considered, and the modeling accuracy is facilitated to be improved.

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

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

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

[0042] Beneficial effects: by constructing the corresponding mass balance equation and enthalpy balance equation of the air spring, and according to the internal energy change rate and the air pressure differential equation, the mass balance equation and the enthalpy balance equation are solved, the air pressure change rate and the temperature change rate of the air spring are obtained, so as to measure the air pressure change and the temperature change of the air spring in the deformation process.

[0043] In an optional embodiment, according to the target air bag volume change amount, the air pressure change rate and the temperature change rate, the air spring is modeled, comprising:

[0044] According to the target air bag volume change amount, the air pressure change rate and the temperature change rate, the power bond graph of the air spring is determined;

[0045] According to the power bond graph, the acting force of the air spring is determined to obtain the target air spring model.

[0046] Beneficial effects: by modeling the target air bag volume change amount, the air pressure change rate and the temperature change rate, the frequency dependence and hysteresis characteristics of the air spring elastic characteristics are more accurately described, and the accuracy and prediction accuracy of the target air spring model are improved.

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

[0048] The acquisition module is used to acquire the structure parameters of the air spring;

[0049] The first processing module is used to determine the target air bag volume change amount of the air spring based on the structure parameters;

[0050] The second processing module is used to determine the air pressure change rate and the temperature change rate of the air spring based on the structure parameters, the preset gas law and the preset thermodynamic law;

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

[0052] In a third aspect, the present application provides a computer device, comprising: a memory and a processor, which are mutually communicated and connected, the memory stores computer instructions, and the processor executes the computer instructions to perform the air spring modeling method of the first aspect or any corresponding embodiment thereof.

[0053] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer instructions, and the computer instructions are used to make the computer execute the air spring modeling method of the first aspect or any corresponding embodiment thereof.

[0054] In a fifth aspect, the present application provides a computer program product comprising computer instructions for causing a computer to perform the air spring modeling method of the first aspect or any of its possible implementation forms. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

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

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

[0058] Figure 3 is a structure diagram of an air spring according to an embodiment of the present application;

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

[0060] Figure 5 is a power bond graph of an air spring according to an embodiment of the present application;

[0061] Figure 6 is a diagram of the air spring stiffness design iteration process according to an embodiment of the present application;

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

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

[0064] Figure 9 is a structure block diagram of an air spring modeling device according to an embodiment of the present application;

[0065] Figure 10 is a hardware structure diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0066] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0067] At present, the air spring used in vehicle dynamics simulation is usually described by three curves as shown in Figure 1 for its elastic characteristics, which are called three-dimensional interpolation model for convenience in description.

[0068] Figure 1 Fig. 1 shows the relationship between the deformation and the force of the air spring under three different initial (corresponding to the 0 deformation moment) inflation pressures. In the traditional vehicle dynamics simulation, the software establishes a three-dimensional surface by using the three curves, and performs AKIMA interpolation calculation on the three-dimensional surface by using a variable (real-time deformation of the air spring) and a parameter (force under the initial inflation pressure) to obtain the force in the third dimension, and simulates the air spring according to the force in the third dimension.

[0069] However, Figure 1 The acquisition approach of the three curves shown in Fig. 1 mainly includes two kinds: one is to calculate and output the finite element model of the air spring established by the air spring supplier to the vehicle enterprise; and the other is to test and output the physical air spring to the vehicle enterprise by the air spring supplier. Obviously, the three-dimensional interpolation model for describing the elastic characteristics of the air spring is very dependent on the supplier.

[0070] And, in the past, the vehicle enterprise usually artificially specifies a static frequency and a dynamic frequency, and then the air spring supplier tests (or performs finite element analysis) to obtain the three-dimensional interpolation model under the two different frequencies, and the vehicle enterprise selects the three-dimensional interpolation model of one frequency according to the working condition to simulate the vehicle dynamics, and when other working conditions need to be simulated, the three-dimensional interpolation model also needs to be switched synchronously. In the above test and simulation process, human factors are inevitably increased, which affects the accuracy and is low in efficiency.

[0071] In addition, according to the theoretical knowledge of aerodynamics and heat transfer, heat is generated in the air spring during the deformation process, heat exchange exists between the inside and the outside, and the heat exchange capacity is different at different working frequencies. That is, the elastic properties of the air spring have frequency dependence and hysteresis characteristics. In the actual use process, the working frequency of the air spring is almost changing all the time, and 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 dependence and hysteresis characteristics of the air spring, resulting in a large error between the vehicle dynamics simulation results and the test results, low simulation accuracy and poor prediction ability.

[0072] Therefore, the embodiment of the present application provides an air spring modeling scheme for vehicle dynamics simulation, which has higher accuracy than the traditional air spring modeling method used in the automobile industry, greatly eliminates human factors, improves the accuracy of vehicle dynamics simulation, and can reduce the dependence on suppliers in the early design stage and output the main characteristic parameters of the air spring.

[0073] According to the embodiment of the present application, an air spring modeling method embodiment 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 here.

[0074] In the present embodiment, an air spring modeling method is provided, which can be used for computer equipment or terminals for air spring modeling, such as computers, tablets, etc. Figure 2 The flowchart of the air spring modeling method according to the embodiment of the present application is shown in FIG. 1, which includes the following steps: Figure 2 As shown in FIG. 1, the flowchart includes the following steps:

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

[0076] Specifically, the air spring is generally provided with a variable cross-section piston, and the volume change of the air bag caused by the displacement movement of the variable cross-section piston is difficult to calculate directly according to the existing parameters, so the variable cross-section piston can be equivalent to a cylindrical piston to facilitate the calculation of the volume change of the air bag of the air spring.

[0077] Specifically, the structure parameters of the air spring mainly include variable cross-section piston displacement, variable cross-section piston structure parameters, cylindrical piston displacement theoretical value, cylindrical piston structure parameters, gas volume and gas pressure, etc. The variable cross-section piston structure parameters include variable cross-section piston diameter. As shown in FIG. 2, the air spring is provided with a variable cross-section piston, and the variable cross-section piston is equivalent to a cylindrical piston. Figure 3As shown, the embodiment of the present application provides a structural schematic diagram of an air spring, which includes a cylindrical piston, and the structural parameters of the cylindrical piston include a cylindrical piston rod diameter dr, a cylindrical piston diameter dp, and a gas bag wall diameter da.

[0078] In step S202, based on the structural parameters, a target gas bag volume change amount of the air spring is determined.

[0079] Specifically, since the piston of the air spring is a variable cross-section, it is difficult to directly determine the structural parameters of the variable cross-section piston, and therefore, the volume change of the gas bag caused by the displacement of the cylindrical piston at a certain moment can be calculated first, then the variable cross-section piston is equivalent to a cylindrical piston, the volume change corresponding to the equivalent cylindrical piston air spring of the variable cross-section piston air spring is calculated, and finally the target gas bag volume change amount of the air spring is obtained.

[0080] In step S203, based on the structural parameters, a preset gas law, and a preset thermodynamic law, a gas pressure change rate and a temperature change rate of the air spring are determined.

[0081] Specifically, since heat is generated in the air spring during deformation, and there is heat exchange between the inside and the outside, the gas pressure change rate and the temperature change rate of the air spring are obtained according to thermodynamics and heat transfer, and the frequency correlation and hysteresis characteristics of the air spring are considered, so as to better describe the elastic characteristics thereof.

[0082] In step S204, the air spring is modeled according to the target gas bag volume change amount, the gas pressure change rate, and the temperature change rate.

[0083] Specifically, according to the target gas bag volume change amount of the air spring during deformation, and considering the gas pressure change and the temperature change in the air spring, the modeling accuracy and the simulation accuracy are improved.

[0084] The air spring modeling method provided in the embodiment determines the target gas bag volume change amount of the air spring based on the structural parameters of the air spring, the preset gas law, and the preset thermodynamic law, and considers the gas pressure change rate and the temperature change rate of the air spring during deformation, thereby improving the accuracy of air spring modeling and the simulation accuracy, and reducing the prediction error. In addition, the development efficiency of vehicle dynamics simulation is improved without relying on the supplier, the introduction of human factors is reduced, and the model accuracy is improved.

[0085] In the embodiment, an air spring modeling method is provided, which can be used for a computer device or terminal for air spring modeling, such as a computer, a tablet computer, etc. Figure 4 is a flowchart of the air spring modeling method according to the embodiment of the present application, as shown in the figure, the flow includes the following steps: Figure 4 ​

[0086] Step S401, obtain the structural parameters of the air spring. For details, please refer to Figure 2 Step S201 of the embodiment shown, which will not be repeated here.

[0087] Step S402, based on the structural parameters, determine the target air bag volume change amount of the air spring.

[0088] Specifically, 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, and 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 air bag volume change amount 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, first calculate the square difference between the cylindrical piston diameter and the cylindrical piston rod diameter. Then, according to the product between the square difference, the cylindrical piston displacement theoretical value and the preset volume calculation coefficient, the first air bag volume change amount caused by the displacement movement of the cylindrical piston is calculated, thereby obtaining the volume change of the air bag caused by the displacement of the cylindrical piston at a certain moment.

[0091] Exemplarily, the first air bag volume change amount can be calculated according to the following formula:

[0092]

[0093] Wherein, vol1 represents the first air bag volume change amount, length1 represents the cylindrical piston displacement theoretical value, dp represents the cylindrical piston diameter, dr represents the cylindrical piston rod diameter, is the preset volume calculation coefficient.

[0094] The present embodiment calculates the first air bag volume change amount by the parameters of the cylindrical piston diameter, the cylindrical piston rod diameter and the cylindrical piston displacement theoretical value, thereby accurately obtaining the volume change of the air bag caused by the displacement of the cylindrical piston at a certain moment.

[0095] Step S4022, set the current value of the variable cross-section piston displacement as the cylindrical piston displacement theoretical value, and determine the second air bag volume change amount 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 second air bag volume change amount caused by the displacement movement of the variable cross-section piston is calculated according to the product between 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.

[0097] Exemplarily, the second air bag volume change amount can be calculated according to the following formula, when the diameter of the variable cross-section piston at a certain time is dy:

[0098]

[0099] vol2=length2×π×(dy / 2)2, wherein vol2 represents the second air bag volume change amount, and length2 represents the variable cross-section piston displacement.

[0100] The embodiment can equivalently regard the variable cross-section piston as a cylindrical piston, set the current value of the variable cross-section piston displacement as the theoretical value of the cylindrical piston displacement, and accurately measure the second air bag volume change amount caused by the displacement movement of the variable cross-section piston according to the variable cross-section piston diameter, thereby reducing the calculation complexity.

[0101] In step S4023, a conversion coefficient is calculated according to the proportional relationship between the first air bag volume change amount and the second air bag volume change amount.

[0102] Specifically, the conversion coefficient k1 is set to make vol1=k1×vol2, and then vol1=vol2×π×(dy / 2)2 / length2 is obtained.

[0103]

[0104] In addition, the current value of the variable cross-section piston displacement is set as the theoretical value of the cylindrical piston displacement in step S4022, that is, length2=length1, and then the conversion coefficient k1 can be obtained according to the ratio of the first air bag volume change amount and the second air bag volume change amount.

[0105]

[0106] The embodiment can measure the conversion relationship between the volume changes caused by the cylindrical piston and the variable cross-section piston according to the proportional relationship between the first air bag volume change amount and the second air bag volume change amount, so as to directly calculate the air bag volume change by using the obtained conversion coefficient and the directly measurable parameters.

[0107] In step S4024, the target air bag volume change amount of the air spring is calculated according to the conversion coefficient, the actual value of the variable cross-section piston displacement, and the cylindrical piston structure 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 air bag volume change amount of the air spring is calculated according to the product of the conversion coefficient, the actual value of the variable cross-section piston displacement, the square difference, and a preset volume calculation coefficient.

[0109] Exemplarily, the target air bag volume change amount can be calculated according to the following formula:

[0110]

[0111] vol = (V0+ ΔV) - V0= ΔV

[0112] The embodiment calculates the target air bag volume change amount by converting the conversion coefficient and the actual value of the variable cross-section piston displacement, so as to obtain the volume change of the variable cross-section piston air spring equivalent to the cylindrical piston air spring.

[0113] In the embodiment, the first air bag volume change amount caused by the displacement movement of the cylindrical piston and the second air bag volume change amount caused by the displacement movement of the variable cross-section piston are determined first, the variable cross-section piston is equivalent to the cylindrical piston, the conversion coefficient is obtained according to the ratio between the first air bag volume change amount and the second air bag volume change amount, so as to obtain the volume change of the variable cross-section piston air spring equivalent to the cylindrical piston air spring.

[0114] In step S403, the air spring pressure change rate and the temperature change rate are determined based on the structure parameters, the preset gas law and the preset thermodynamic law.

[0115] Specifically, the above step S403 includes:

[0116] In step S4031, the air spring corresponding pressure differential equation is determined based on the structure parameters and according to the polytropic gas law and the ideal gas law.

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

[0118] In step a1, a first expression is obtained based on the polytropic gas law, the first expression is used to represent 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.

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

[0120] P·V k2 = constant1

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

[0122] In step a2, a second expression is calculated based on the ideal gas law and the first expression. The ideal gas law is used to represent that the product of the gas pressure and the gas volume diameter is equal to the product of the amount of substance of the gas, the molar gas constant and the temperature, and the second expression is used to represent that the product of the second power of the gas pressure and the first power of the temperature is a 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] wherein n represents the amount of substance of the gas, r represents the molar gas constant, and T represents the temperature.

[0126] Further, the ideal gas law is substituted into the first expression to obtain a second expression:

[0127] P 1-k2 ·T k2 =constant2

[0128] wherein constant2 represents a second constant.

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

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

[0131]

[0132] Step a4, based on the first differential equation and the differentiation of the ideal gas law, the air spring corresponding air pressure differential equation is calculated.

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

[0134]

[0135] In the embodiments of the present application, according to the polytropic gas law and the ideal gas law, the air spring corresponding air pressure differential equation is calculated in combination with the thermodynamic effect, so as to consider the air pressure change of the air spring in the deformation process, thereby facilitating to improve the modeling accuracy.

[0136] Step S4032, 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.

[0137] Specifically, first, the internal energy change rate of the air spring is determined based on the structural parameters and the first law of thermodynamics, and the air spring corresponding balance equation is constructed, the balance equation includes mass balance equation and 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. 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] Exemplarily, considering the thermodynamic effect, applying the first law of thermodynamics, an internal energy change rate equation related to internal energy U is introduced as follows:

[0139]

[0140] wherein, represents the internal energy change rate, represents the input heat flow rate, represents the heat flow rate flowing through the effective volume, represents the work pressure.

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

[0142]

[0143] wherein, represents the volume change amount.

[0144] Further, the mass unit related to the internal energy is introduced as follows:

[0145] U = m · u

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

[0147] Further, substituting U = m · u into the above internal energy change rate equation, it is obtained that:

[0148]

[0149] Then, according to the work pressure and other parameters, it is obtained that:

[0150]

[0151] wherein, c v represents the constant volume specific heat capacity.

[0152] Finally, according to the gas pressure differential equation and the internal energy differential, by solving the mass balance equation and the enthalpy balance equation as follows, the temperature and pressure derivatives of the pressure vessel with respect to time, i.e., the temperature change rate and the gas pressure change rate

[0153]

[0154] In the embodiments of the present application, by constructing the mass balance equation and the enthalpy balance equation corresponding to the air spring, and solving the mass balance equation and the enthalpy balance equation according to the internal energy change rate and the gas pressure differential equation, the gas pressure change rate and the temperature change rate of the air spring are obtained, so as to measure the gas pressure change and the temperature change of the air spring in the deformation process.

[0155] Step S404: Model the air spring based on the change in target airbag volume, the rate of change in air pressure, and the rate of change in temperature.

[0156] Specifically, step S404 includes:

[0157] S4041, Determine the power bond diagram of the air spring based on the target airbag volume change, air pressure change rate, and temperature change rate.

[0158] Specifically, such as Figure 5 As shown, considering the air pressure change rate and temperature change rate of the air spring, a power bond graph capable of calculating thermodynamic effects is constructed. At the same time, based on the change in the target airbag volume, a power bond graph capable of calculating the airbag pressure and volume is constructed.

[0159] S4042, determine the force of the air spring based on the power bond diagram to obtain the target air spring model.

[0160] Specifically, according to such Figure 5 The power bond diagram shown is used to calculate the force of the air spring, thereby modeling the target air spring.

[0161] In some alternative implementations, an air spring model can be established. In addition to using power bond graph modeling software, mathematical calculation software such as MATLAB can be used to solve for the air spring properties using the formulas listed in the embodiments of this invention and perform joint simulation with the vehicle dynamics model.

[0162] This embodiment models the target air spring by using the change in target airbag volume, the rate of change in air pressure, and the rate of change in temperature. This more accurately describes the frequency correlation and hysteresis characteristics of the air spring's elastic properties, thus improving the accuracy of the target air spring model and its prediction accuracy.

[0163] In this embodiment, starting from the gas state equation and heat transfer principle, the equivalent volume change of the piston during the deformation process of the air spring is calculated. At the same time, the formulas for gas mass balance and enthalpy balance are introduced to calculate the gas pressure change inside the air spring. Finally, the force generated by the air spring is calculated, which improves the accuracy of air spring modeling.

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

[0165] 1) Improved agility in vehicle dynamics simulation: This invention eliminates the need for suppliers to provide the elastic characteristic curves of the air springs for building a 3D interpolation model, reducing dependence on suppliers. This invention only requires the engineering department to provide basic dimensional parameters such as the air spring outer diameter and piston profile to calculate the air spring's elastic characteristics. Furthermore, as... Figure 6As shown, the application can also provide optimized air spring structure parameters according to simulation results for engineering design iteration.

[0166] 2) Directly using a set of simulation models for calculation, high efficiency: unlike the traditional vehicle dynamics simulation method which selects different three-dimensional interpolation models of air springs with different frequencies according to different simulation conditions, the application uses only one set of air spring models in vehicle simulation, which can adapt to various simulation conditions without manual discrimination and switching.

[0167] 3) Considering the frequency dependence and hysteresis characteristics of air spring stiffness, good accuracy: unlike the traditional interpolation method, the application considers the variation characteristics of air spring stiffness under different motion frequencies, and can also reflect the hysteresis characteristics of air spring, with good accuracy. For example, Figure 7 As shown, according to the air spring model of the application for simulation and test, it can be seen that the curve coincidence rate of the simulation result and the test result is high, that is, the model constructed by the application can well simulate the variation characteristics of air spring stiffness.

[0168] As shown, Figure 8 The application provides a comparison chart compared with the traditional vehicle dynamics simulation using a three-dimensional interpolation model. In summary, the application 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 define the structure parameters of air springs through joint simulation method, thus getting rid of the dependence on suppliers; and can adapt to different conditions without defining the working state of air springs by human, reducing the interference of human factors, and saving the process of manually switching the three-dimensional interpolation model of air springs; in addition, it can more accurately describe the frequency dependence and hysteresis characteristics of air spring elastic properties.

[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 will not be described again. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware implementation is also possible and contemplated.

[0170] The embodiment provides an air spring modeling device, as shown in Figure 9 The embodiment provides an air spring modeling device, as shown in

[0171] The acquisition module 901 is configured to acquire the structure parameters of the air spring.

[0172] The first processing module 902 is configured to determine a target air bag volume change amount of the air spring based on the structure parameters.

[0173] The second processing module 903 is configured to determine the air pressure change rate and the temperature change rate of the air spring based on the structural parameter, the preset gas law, and the preset thermodynamic law.

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

[0175] In some optional embodiments, the air spring is provided with a variable cross-section piston, and the structural parameter includes a variable cross-section piston displacement, a variable cross-section piston structural parameter, a theoretical value of a cylindrical piston displacement, and a cylindrical piston structural parameter; the first processing module 902 is further configured to:

[0176] determine a first air bag volume change amount caused by displacement movement of the cylindrical piston based on the theoretical value of the cylindrical piston displacement and the cylindrical piston structural parameter;

[0177] set a current value of the variable cross-section piston displacement as the theoretical value of the cylindrical piston displacement, and determine a second air bag volume change amount caused by displacement movement of the variable cross-section piston according to the variable cross-section piston structural parameter;

[0178] calculate a conversion coefficient according to a proportional relationship between the first air bag volume change amount and the second air bag volume change amount;

[0179] calculate the target air bag volume change amount of the air spring according to the conversion coefficient, an actual value of the variable cross-section piston displacement, and the cylindrical piston structural parameter.

[0180] In some optional embodiments, the cylindrical piston structural parameter includes a cylindrical piston rod diameter and a cylindrical piston diameter; the first processing module 902 is further configured to:

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

[0182] calculate the first air bag volume change amount caused by displacement movement of the cylindrical piston according to a product of the square difference, the theoretical value of the cylindrical piston displacement, and a preset volume calculation coefficient.

[0183] In some optional embodiments, the variable cross-section piston structural parameter includes a variable cross-section piston diameter; the first processing module 902 is further configured to:

[0184] calculate the second air bag volume change amount caused by displacement movement of the variable cross-section piston according to a product of a square of the variable cross-section piston diameter, a current value of the variable cross-section piston displacement, and a preset volume calculation coefficient.

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

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

[0187] The target air bag volume change amount of the air spring is calculated according to a product of the conversion coefficient, an actual value of the variable cross-section piston displacement, a square difference, and a preset volume calculation coefficient.

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

[0189] Based on the structural parameters, a polytropic gas law, and an ideal gas law, determine a corresponding air pressure differential equation of the air spring;

[0190] According to the structural parameters, the air pressure differential equation, and the first law of thermodynamics, determine the air pressure change rate and the temperature change rate of the air spring.

[0191] In some optional embodiments, the structural parameters include the gas volume and the air pressure; and the second processing module 903 is further configured to:

[0192] Based on the polytropic gas law, obtain a first expression, the first expression being used to represent that a product of the first power of the gas volume and the air pressure is a first constant, the first power being a polytropic index of the gas;

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

[0194] Differential the second expression to obtain a first differential equation of the air temperature with respect to the air pressure;

[0195] Based on the first differential equation and the ideal gas law, calculate a corresponding air pressure differential equation of the air spring.

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

[0197] Based on the structural parameters and the first law of thermodynamics, determine the internal energy change rate of the air spring, and construct a corresponding balance equation of the air spring; the balance equation includes a mass balance equation and an enthalpy balance equation, and 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, solve the mass balance equation and the enthalpy balance equation to obtain the air pressure change rate and the temperature change rate of the air spring.

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

[0200] The power bond diagram of the air spring is determined based on the change in target airbag volume, the rate of change in air pressure, and the rate of change in temperature.

[0201] The force exerted by the air spring is determined based on the power bond diagram, and the target air spring model is obtained.

[0202] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

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

[0204] This invention also provides a computer device having the above-described features. Figure 9 The air spring modeling device shown.

[0205] Please see Figure 10 , Figure 10 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 10 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 10 Take a processor 10 as an example.

[0206] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0207] The memory 20 stores instructions executable by the at least one processor 10 to cause the at least one processor 10 to perform the methods implemented by the above-described embodiments.

[0208] The memory 20 can include a program region and a data region. The program region can store an operating system and application programs required by at least one function. The data region can store data created according to use of the computer device, and the like. In addition, the memory 20 can include a high-speed random access memory, and can further include a non-transitory memory such as at least one of a magnetic disk storage device, a flash memory device, or other non-transitory solid-state memory device. In some alternative embodiments, the memory 20 can optionally include a memory disposed remotely with respect to the processor 10, and these remote memories can be connected to the computer device through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0209] The memory 20 can include a volatile memory such as a random access memory, and can further include a non-volatile memory such as a flash memory, a hard disk, or a solid state disk. The memory 20 can also include a combination of the above-mentioned types of memories.

[0210] The computer device further 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 can be connected by a bus or other means, Figure 10 For example, by way of example, by a bus connection.

[0211] The input device 30 can receive input numerical or character information, and generate key signal inputs related to user settings and function controls of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touchpad, a pointing stick, one or more mouse buttons, a trackball, a joystick, and the like. The output device 40 can include a display device, an auxiliary lighting device (e.g., an LED), a tactile feedback device (e.g., a vibration motor), and the like. The display device includes, but is not limited to, a liquid crystal display, a light-emitting diode, a display, and a plasma display. In some alternative embodiments, the display device can be a touch screen.

[0212] The embodiments of the present application further provide a computer readable storage medium, and the method according to the embodiments of the present application can be implemented in hardware, firmware, or recorded in a storage medium, or stored in a remote storage medium or a non-transitory machine readable storage medium and downloaded to a local storage medium through network, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor, or programmable or special hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid state disk, etc. Further, the storage medium can also include a combination of the above-mentioned memories. It can be understood that the computer, the processor, the microprocessor controller, or the 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 the computer, the processor, or the hardware, the method shown in the above embodiments is implemented.

[0213] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, the method and / or technical solutions according to the present application can be called or provided. Those skilled in the art should understand that the form of computer program instructions in a computer readable medium includes but is not limited to source files, executable files, installation package files, etc. Correspondingly, the way of executing computer program instructions by computer includes but is not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0214] Although the embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A method for modeling air springs, characterized in that, The method includes: Obtain the structural parameters of the air spring; Based on the structural parameters, the target airbag volume change of the air spring is determined; the structural parameters include gas volume and gas pressure. The first expression is obtained based on the law of polytropic gases. The first expression is used to characterize the product of the first power of the gas volume and the gas pressure as a first constant. 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 substance of the gas, and the product of the molar gas constant and 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, wherein the second power is calculated based on the gas polytropic index; Differentiating the second expression yields the first differential equation of air temperature relative to air pressure; Based on the first differential equation and the ideal gas law, the air pressure differential equation corresponding to the air spring is calculated by differentiation. Based on the structural parameters and the first law of thermodynamics, the rate of change of internal energy of the air spring is determined, and the corresponding equilibrium equation is constructed. The equilibrium 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 the rate of change of air pressure and the rate of change of temperature. Based on the internal energy change rate and the air pressure differential equation, the mass balance equation and enthalpy balance equation are solved to obtain the air pressure change rate and temperature change rate of the air spring. The air spring is modeled based on the change in the target airbag volume, the rate of change in air pressure, and the rate of change in temperature.

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

3. The method according to claim 2, characterized in that, The cylindrical piston structural parameters include the diameter of the cylindrical piston rod and the diameter of the cylindrical piston; determining the change in the volume of the first airbag caused by the displacement movement of the cylindrical piston based on the theoretical value of the cylindrical piston displacement and the cylindrical piston structural parameters includes: Calculate the squared difference between the diameter of the cylindrical piston and the diameter of the cylindrical piston rod; The change in volume of the first airbag caused by the displacement motion 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 structural parameters of the variable cross-section piston include the diameter of the variable cross-section piston; determining the volume change of the second airbag caused by the displacement movement of the variable cross-section piston based on the structural parameters of the variable cross-section piston includes: The change in volume of the second airbag caused by the displacement of the variable cross-section piston is calculated by multiplying the square of the diameter of the variable cross-section piston, the current value of the displacement of the variable cross-section piston, and the preset volume calculation coefficient.

5. The method according to claim 3, characterized in that, The calculation of the target airbag volume change of the air spring based on the conversion coefficient, the actual value of the variable cross-section piston displacement, and the cylindrical piston structural parameters includes: Calculate the squared 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 cross-section piston displacement, the product of the square difference and the preset volume calculation coefficient.

6. The method according to any one of claims 1-5, characterized in that, The step of modeling the air spring based on the change in the target airbag volume, the rate of change in air pressure, and the rate of change in temperature includes: The power bond diagram of the air spring is determined based on the target airbag volume change, the air pressure change rate, and the temperature change rate. The force of the air spring is determined based on the power bond diagram, and the target air spring model is obtained.

7. An air spring modeling device, characterized in that, The device includes: The acquisition module is used to acquire the structural parameters of the air spring; The first processing module is used to determine the target airbag volume change of the air spring based on the structural parameters; the structural parameters include gas volume and air pressure. The second processing module is used for: The first expression is obtained based on the law of polytropic gases. The first expression is used to characterize the product of the first power of the gas volume and the gas pressure as a first constant. 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 substance of the gas, and the product of the molar gas constant and 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, wherein the second power is calculated based on the gas polytropic index; Differentiating the second expression yields the first differential equation of air temperature relative to air pressure; Based on the first differential equation and the ideal gas law, the air pressure differential equation corresponding to the air spring is calculated by differentiation. Based on the structural parameters and the first law of thermodynamics, the rate of change of internal energy of the air spring is determined, and the corresponding equilibrium equation is constructed. The equilibrium 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 the rate of change of air pressure and the rate of change of temperature. Based on the internal energy change rate and the air pressure differential equation, the mass balance equation and enthalpy balance equation are solved to obtain the air pressure change rate and temperature change rate of the air spring. The third processing module is used to model the air spring based on the change in the target airbag volume, the rate of change in air pressure, and the rate of change in temperature.

8. A computer device, characterized in that, include: A memory and a processor are interconnected, the memory storing computer instructions, and the processor executing the computer instructions to perform the air spring modeling method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a computer to perform the air spring modeling method according to any one of claims 1 to 6.

10. A computer program product, characterized in that, Includes computer instructions for causing a computer to execute the air spring modeling method according to any one of claims 1 to 6.

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