Method and system for calculating influence of electric vehicle tire rolling resistance on energy consumption based on cold region working conditions

Abstract

The invention discloses a method and system for calculating the influence of electric vehicle tire rolling resistance on energy consumption based on cold region working conditions, and belongs to the field of electric vehicle energy consumption calculation. An existing electric vehicle energy consumption calculation method has the defects in the aspects of calculation precision, environmental adaptability and the like. According to the method, a multi-factor coupled tire rolling state finite element model under the low-temperature working condition is constructed by coupling the environment temperature, the road surface condition, the running speed, the tire pressure and the vertical load condition; through a finite element model, strain energy density accumulated values of all tire rubber material units are extracted, all the tire rubber material units are partitioned and labeled according to angles, then the strain energy density accumulated values are calculated, and a tire rolling energy consumption loss model is obtained; through calculation of the tire rolling energy consumption loss and the energy consumption of the electric vehicle, energy consumption caused by tire rolling is obtained, and then the influence of the tire rolling resistance on the energy consumption is obtained. The calculation precision of the energy consumption of the electric vehicle is improved through a multi-factor coupling verification model such as the temperature and the road surface.

Description

Technical Field

[0001] This invention relates to the calculation of vehicle energy consumption, and particularly to a method for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions. Background Technology

[0002] Early tire rolling resistance calculations relied on physical experiments, such as drum tests (drum shaft torque method, power method, etc.), requiring the fabrication of physical tires and simulation of real-world conditions, which was costly and time-consuming. For example, industrial vehicle tires need to be tested using the axle-weighted force method or deceleration method before being put back into service, but these experiments require extremely high equipment precision, and solid tires require frequent calibration because they cannot reach thermal equilibrium. With the development of technology, simulation techniques based on finite element analysis have gradually become widespread. Examples include Fourier transform, strain energy density method, and real-time estimation algorithms. While simulation methods are efficient, the efficiency of traditional Fourier transform methods drops sharply when dealing with tires with complex tread patterns, and multiple iterative design optimizations are required, which is time-consuming and easily overlooks the effects of multi-factor coupling, resulting in reduced calculation accuracy.

[0003] In summary, existing methods have shortcomings in terms of calculation accuracy and environmental adaptability. A calculation method that balances high accuracy with multi-factor coupling is needed to meet the calculation requirements for tire rolling resistance under cold-region conditions. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing electric vehicle energy consumption calculation methods in terms of calculation accuracy and environmental adaptability, and to propose a calculation method for the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions.

[0005] The above objectives are achieved through the following technical solutions:

[0006] A method for calculating the impact of tire rolling resistance on energy consumption of electric vehicles under cold-region operating conditions, the method being implemented through the following steps:

[0007] Step 1: Construct a finite element model of the tire by verifying the statics and dynamics of the tire during the rolling process;

[0008] Step 2: By changing the coefficients of various structural materials of the tire at different low temperatures, a finite element model of the tire defined by the ambient temperature is constructed.

[0009] Step 3: By changing different road surface conditions and different road surface friction coefficients, construct a tire finite element model defined by the driving road surface conditions;

[0010] Step 4: By changing different tire rolling speeds, simulate the change in vehicle speed and construct a tire finite element model defined by the driving speed;

[0011] Step 5: By changing different tire pressures, simulate the changes in tire pressure during vehicle operation, and construct a tire finite element model defined by tire pressure;

[0012] Step 6: By changing the vertical load acting on the central axle, simulate the changes in vehicle load during daily use and construct a tire finite element model defined by the vertical load;

[0013] Step 7: By coupling ambient temperature, road conditions, driving speed, tire pressure, and vertical load conditions, construct a multi-factor coupled finite element model of tire rolling state under low-temperature conditions.

[0014] Step 8: Through the analysis of the results of the finite element model of the tire rolling state, extract the cumulative value of strain energy density of all tire rubber material elements, and divide all tire rubber material elements into blocks according to angle and label them;

[0015] Step 9: Obtain the tire rolling energy loss model by calculating the cumulative strain energy density of all tire rubber material units;

[0016] Step 10: Calculate the energy consumption caused by tire rolling by combining the energy loss from tire rolling with the energy consumption of the electric vehicle.

[0017] Step 11: By comparing the energy consumption per kilometer of tire rolling with the energy consumption of the electric vehicle, the influence of tire rolling resistance on energy consumption under low-temperature conditions is obtained.

[0018] Furthermore, in step one, the steps for verifying the statics and dynamics of the tire during its rolling process...

[0019] The verification of tire statics includes: tire static inflation deformation, tire static load deformation, tire static temperature rise characteristics, and tire static load vibration modal characteristics.

[0020] The dynamics verification includes: tire pressure change during rolling, tire deformation under rolling load, temperature rise characteristics under rolling load, and modal characteristics of tire rolling.

[0021] Furthermore, in step two, which describes constructing a tire finite element model defined by ambient temperature by changing the coefficients of various structural materials of the tire at different low temperatures, the coefficients of hardness, elastic modulus, density, and tire materials of various structural materials change due to the change in ambient temperature. Among these changes, the coefficients of tire materials include those of the tread layer, belt layer, inner liner, carcass, sidewall, triangular rubber, and steel cord structure.

[0022] Furthermore, in step seven, the step of constructing a multi-factor coupled finite element model of tire rolling state under low-temperature conditions by coupling ambient temperature, road conditions, driving speed, tire pressure, and vertical load conditions,

[0023] The calculations involved in the finite element model include:

[0024] By using a mapping mechanism, the difference in strain energy density of each rubber material element at the same location on the tire is calculated, resulting in the cumulative strain energy density:

[0025] Δ=|e n+1,i -e n,i | (1)

[0026] Where e represents the element strain energy density, with units of J / mm². 3 n represents the tire block number, and i represents the tire block unit position number.

[0027] The total energy loss equals the work done by the tire's rolling resistance, and the energy loss of each rubber material unit is:

[0028]

[0029] Among them, h i The energy loss of a rubber material unit is expressed in J; k represents the number of tire blocks, expressed in pieces; tanδ i This represents the material loss tangent for rubber material unit number i.

[0030] The tire rolling resistance is:

[0031]

[0032] Where R represents tire rolling resistance, in N; m represents the total number of rubber material units, in units; r represents the radius of the longitudinal section of the tire containing the rubber material unit numbered i, in mm; V i This represents the volume of the rubber material unit numbered i when it rotates around a radius of r in one revolution, in mm. 3 ;

[0033] The tire rolling resistance coefficient f is:

[0034] f = R / F v (4) F v This indicates the vertical load on the tire, measured in N (newtons).

[0035] The energy consumption ratio of rolling resistance per kilometer is:

[0036]

[0037] Where q represents the percentage of energy consumed by rolling resistance per kilometer, expressed as a percentage; Q represents the total energy consumed per kilometer of electric vehicle driving, in mJ.

[0038] A calculation system for the impact of electric vehicle tire rolling resistance on energy consumption under cold-region operating conditions is applied to a calculation method for the impact of electric vehicle tire rolling resistance on energy consumption under cold-region operating conditions. The system includes:

[0039] The tire finite element construction module is used to build a tire finite element model by verifying the statics and dynamics of the tire during the rolling process of automobile tires;

[0040] The tire finite element model building module defined by ambient temperature is used to build a tire finite element model defined by ambient temperature by changing the coefficients of various structural materials of the tire at different low temperatures.

[0041] The tire finite element model building module, defined by driving road conditions, is used to build a tire finite element model defined by driving road conditions by changing different road conditions and different road friction coefficients.

[0042] The tire finite element model building module, which defines the driving speed, is used to simulate changes in vehicle driving speed by changing different tire rolling speeds and to build a tire finite element model defined by the driving speed.

[0043] The tire finite element model building module, defined by tire pressure, is used to simulate the changes in tire pressure during vehicle operation by changing different tire pressures, and to build a tire finite element model defined by tire pressure.

[0044] The tire finite element model building module defined by vertical load is used to simulate the load changes of a vehicle in daily use by changing the vertical load acting on the central axle, and to build a tire finite element model defined by vertical load.

[0045] The multi-factor coupled tire rolling state finite element model construction module is used to construct a multi-factor coupled tire rolling state finite element model under low temperature conditions by coupling ambient temperature, road conditions, driving speed, tire pressure, and vertical load conditions.

[0046] The segmentation and labeling module is used to extract the cumulative strain energy density of all tire rubber material elements by analyzing the results of the finite element model of the tire rolling state, and to segment and label all tire rubber material elements according to angles.

[0047] The tire rolling energy loss model calculation module is used to obtain the tire rolling energy loss model by calculating the cumulative value of strain energy density of all tire rubber material units;

[0048] The module for calculating energy consumption due to tire rolling is used to calculate the energy consumption due to tire rolling by comparing the energy loss due to tire rolling with the energy consumption of electric vehicles.

[0049] The influence determination module is used to determine the influence of tire rolling resistance on energy consumption under low-temperature conditions by comparing the energy consumption caused by tire rolling per kilometer with the energy consumption of the electric vehicle.

[0050] Furthermore, the tire statics verification performed by the tire finite element construction module includes: tire static inflation deformation, tire static load deformation, tire static temperature rise characteristics, and tire static load vibration mode characteristics.

[0051] The dynamic verification content of the tire finite element construction module includes: tire rolling pressure change, tire rolling load deformation, tire rolling load temperature rise characteristics, and tire rolling modal characteristics.

[0052] Furthermore, the tire finite element model construction module defined by ambient temperature is affected by changes in ambient temperature, resulting in changes in the hardness coefficient, elastic modulus, density, and coefficients of various tire structural materials. Among these changes, the coefficients of tire materials include those of the tread layer, belt layer, inner liner, carcass, sidewall, triangular rubber, and steel cord structure.

[0053] Furthermore, in the process of constructing the multi-factor coupled tire rolling state finite element model module, during the construction of the multi-factor coupled tire rolling state finite element model under low-temperature conditions,

[0054] The calculations involved in the finite element model include:

[0055] By using a mapping mechanism, the difference in strain energy density of each rubber material element at the same location on the tire is calculated, resulting in the cumulative strain energy density:

[0056] Δ=|e n+1,i -e n,i | (1)

[0057] Where e represents the element strain energy density, with units of J / mm². 3 n represents the tire block number, and i represents the tire block unit position number.

[0058] The total energy loss equals the work done by the tire's rolling resistance, and the energy loss of each rubber material unit is:

[0059]

[0060] Among them, h i The energy loss of a rubber material unit is expressed in J; k represents the number of tire blocks, expressed in pieces; tanδi This represents the material loss tangent for rubber material unit number i.

[0061] The tire rolling resistance is:

[0062]

[0063] Where R represents tire rolling resistance, in N; m represents the total number of rubber material units, in units; r represents the radius of the longitudinal section of the tire containing the rubber material unit numbered i, in mm; V i This represents the volume of the rubber material unit numbered i when it rotates around a radius of r in one revolution, in mm. 3 ;

[0064] The tire rolling resistance coefficient f is:

[0065] f = R / F v (4) F v This indicates the vertical load on the tire, measured in N (newtons).

[0066] The energy consumption ratio of rolling resistance per kilometer is:

[0067]

[0068] Where q represents the percentage of energy consumed by rolling resistance per kilometer, expressed as a percentage; Q represents the total energy consumed per kilometer of electric vehicle driving, in mJ.

[0069] An apparatus for calculating the impact of tire rolling resistance on energy consumption of electric vehicles based on cold-region operating conditions, comprising:

[0070] processor;

[0071] A memory in which executable instructions of the processor are stored;

[0072] The processor is configured to execute steps of a method for calculating the impact of tire rolling resistance on energy consumption of electric vehicles based on cold-region operating conditions by executing the executable instructions.

[0073] A computer-readable storage medium for storing a program, which, when executed, implements the steps of a method for calculating the impact of tire rolling resistance on energy consumption of electric vehicles under cold-region operating conditions.

[0074] The beneficial effects of this invention are as follows:

[0075] This invention addresses the impact of tire rolling resistance on energy consumption in electric vehicles under cold-climate conditions, providing a theoretical basis for the promotion and technological improvement of electric vehicles in cold regions. To address the coupling effect of tire material property changes and complex road conditions in low-temperature environments, a multi-condition tire rolling resistance calculation model is constructed. This model simulates the dynamic deformation data of tires under different low-temperature gradients (-30℃ to 0℃), tire pressure conditions, and on icy, snowy, and icy-snowy road surfaces in cold-climate environments. A tire hysteresis loss model is established, incorporating the cumulative value of temperature-dependent rubber material strain energy density for calculation. A tread-road friction model is also established to calculate energy loss. Combined with vehicle dynamics parameters, the rolling resistance variation curve is solved. The rolling resistance is then input into the overall vehicle energy consumption model. This method innovatively couples tire rolling thermodynamics with road surface changes for analysis. Compared to traditional standard testing methods, this research provides a theoretical foundation for predicting the driving range of electric vehicles in cold regions and optimizing low-temperature energy management strategies.

[0076] By considering the influence of multiple factors on the tire finite element model, the finite element model is more realistic. Validating the model through coupling multiple factors such as temperature and road surface significantly improves computational accuracy. Attached Figure Description

[0077] Figure 1 This is a flowchart of the method of the present invention;

[0078] Figure 2 This invention relates to a tire geometry model;

[0079] Figure 3 This invention relates to a tire finite element model;

[0080] Figure 4 This is a schematic diagram of a tire fragment corresponding to the calculation of cumulative strain energy density involved in this invention;

[0081] Figure 5 This invention relates to a finite element model of tire rolling under low-temperature operating conditions;

[0082] Figure 6 This invention relates to a finite element model of tire strain energy density. Detailed Implementation

[0083] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Specific implementation method one:

[0085] This embodiment provides a method for calculating the impact of electric vehicle tire rolling resistance on energy consumption under cold-region operating conditions, such as... Figure 1 As shown, the method is implemented through the following steps:

[0086] Step 1: Construct a finite element model of the tire by verifying the statics and dynamics of the tire during the rolling process;

[0087] Step 2: By changing the coefficients of various structural materials of the tire at different low temperatures, a finite element model of the tire defined by the ambient temperature is constructed.

[0088] Step 3: Since road conditions are variable, the coefficient of friction between the tire and the road surface changes depending on the road conditions, such as icy or snowy surfaces. Therefore, by changing different road conditions and different road friction coefficients, a finite element model of the tire defined by the driving road conditions is constructed.

[0089] Step 4: Since it is extremely unlikely that a vehicle will travel at the same speed throughout its journey, we simulate the change in vehicle speed by changing the rolling speed of different tires, and construct a tire finite element model defined by the driving speed.

[0090] Step 5: By changing different tire pressures, simulate the changes in tire pressure during vehicle operation, and construct a tire finite element model defined by tire pressure;

[0091] Step 6: By changing the vertical load acting on the central axle, simulate the changes in vehicle load during daily use and construct a tire finite element model defined by the vertical load;

[0092] Step 7: By coupling different conditions such as ambient temperature, road surface conditions, driving speed, tire pressure, and vertical load, construct a multi-factor coupled finite element model of tire rolling state under low-temperature conditions.

[0093] Step 8: Through the analysis of the results of the finite element model of the tire rolling state, extract the cumulative value of strain energy density of all tire rubber material elements, and divide all tire rubber material elements into blocks according to angle and label them;

[0094] Step 9: Obtain the tire rolling energy loss model by calculating the cumulative strain energy density of all tire rubber material units;

[0095] Step 10: Calculate the energy consumption caused by tire rolling by combining the energy loss from tire rolling with the energy consumption of the electric vehicle.

[0096] Step 11: By comparing the energy consumption per kilometer of tire rolling with the energy consumption of the electric vehicle, the influence of tire rolling resistance on energy consumption under low-temperature conditions is obtained. Specific Implementation Method Two:

[0098] This embodiment provides a method for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions. The difference between this method and the first embodiment is that, in step one, the step of verifying the tire statics and dynamics during tire rolling is omitted.

[0099] The verification of tire statics includes: tire static inflation deformation, tire static load deformation, tire static temperature rise characteristics, and tire static load vibration modal characteristics.

[0100] The dynamics verification includes: tire pressure change during rolling, tire deformation under rolling load, temperature rise characteristics under rolling load, and modal characteristics of tire rolling. Specific implementation method three:

[0102] This embodiment of the method for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions differs from specific embodiments one or two in that, in step two, which involves constructing a tire finite element model defined by ambient temperature by changing the coefficients of various structural materials of the tire at different low temperatures, the coefficients of hardness, elastic modulus, density, and tire materials change due to the change in ambient temperature. Among these changes, the coefficients of tire materials include those of the tread layer, belt layer, inner liner, carcass, sidewall, triangular rubber, and steel cord structure. Specific implementation method four:

[0104] This embodiment of the method for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions differs from specific embodiment three in that, in step seven, the step of constructing a multi-factor coupled finite element model of tire rolling state under low-temperature operating conditions by coupling different conditions such as ambient temperature, road surface conditions, driving speed, tire pressure, and vertical load is omitted.

[0105] A tire finite element model is constructed by coupling multiple factors. By setting the ambient temperature, road conditions, rolling speed, tire pressure, and vertical load separately, the realism of the tire finite element model is ensured to conform to the normal driving conditions of vehicles, and the constructed tire finite element model results are realistic.

[0106] The calculations involved in the finite element model include:

[0107] By using a mapping mechanism, the difference in strain energy density of each rubber material element at the same location on the tire is calculated, resulting in the cumulative strain energy density:

[0108] Δ=|e n+1,i -e n,i | (1)

[0109] Where e represents the element strain energy density, with units of J / mm². 3n represents the tire block number, and i represents the tire block unit position number.

[0110] The total energy loss equals the work done by the tire rolling resistance. Due to possible simplifications in the model, the calculation of rolling resistance considers the average radius of each element. The energy loss of each rubber material element is:

[0111]

[0112] Among them, h i The energy loss of a rubber material unit is expressed in J; k represents the number of tire blocks, expressed in pieces; tanδ i This represents the material loss tangent for rubber material unit number i.

[0113] The tire rolling resistance is:

[0114]

[0115] Where R represents tire rolling resistance, in N; m represents the total number of rubber material units, in units; r represents the radius of the longitudinal section of the tire containing the rubber material unit numbered i, in mm; V i This represents the volume of the rubber material unit numbered i when it rotates around a radius of r in one revolution, in mm. 3 ;

[0116] The tire rolling resistance coefficient f is:

[0117] f = R / F v (4) F v This indicates the vertical load on the tire, measured in N (newtons).

[0118] The energy consumption ratio of rolling resistance per kilometer is:

[0119]

[0120] Where q represents the percentage of energy consumed by rolling resistance per kilometer, expressed as a percentage; Q represents the total energy consumed per kilometer of electric vehicle driving, in mJ. Specific implementation method five:

[0122] This embodiment provides a calculation system for the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions. This system is applied to a method for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions. The system includes:

[0123] The tire finite element construction module is used to build a tire finite element model by verifying the statics and dynamics of the tire during the rolling process of automobile tires;

[0124] The tire finite element model building module defined by ambient temperature is used to build a tire finite element model defined by ambient temperature by changing the coefficients of various structural materials of the tire at different low temperatures.

[0125] The tire finite element model construction module, defined by driving road surface conditions, is used to construct a tire finite element model defined by driving road surface conditions by changing the tire-road friction coefficient due to the variability of road surface conditions, such as ice road surface and snow road surface.

[0126] The tire finite element model building module defined by driving speed is used to simulate the change of vehicle speed by changing different tire rolling speeds, since the possibility of a vehicle always traveling at the same speed is extremely small.

[0127] The tire finite element model building module, defined by tire pressure, is used to simulate the changes in tire pressure during vehicle operation by changing different tire pressures, and to build a tire finite element model defined by tire pressure.

[0128] The tire finite element model building module defined by vertical load is used to simulate the load changes of a vehicle in daily use by changing the vertical load acting on the central axle, and to build a tire finite element model defined by vertical load.

[0129] The multi-factor coupled tire rolling state finite element model construction module is used to construct a multi-factor coupled tire rolling state finite element model under low temperature conditions by coupling different conditions such as ambient temperature, road conditions, driving speed, tire pressure, and vertical load.

[0130] The segmentation and labeling module is used to extract the cumulative strain energy density of all tire rubber material elements by analyzing the results of the finite element model of the tire rolling state, and to segment and label all tire rubber material elements according to angles.

[0131] The tire rolling energy loss model calculation module is used to obtain the tire rolling energy loss model by calculating the cumulative value of strain energy density of all tire rubber material units;

[0132] The module for calculating energy consumption due to tire rolling is used to calculate the energy consumption due to tire rolling by comparing the energy loss due to tire rolling with the energy consumption of electric vehicles.

[0133] The influence determination module is used to determine the influence of tire rolling resistance on energy consumption under low-temperature conditions by comparing the energy consumption caused by tire rolling per kilometer with the energy consumption of the electric vehicle. Specific implementation method six:

[0135] This embodiment of the calculation system for the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region working conditions differs from specific embodiment five in that the tire finite element construction module performs tire static verification including: tire static inflation deformation, tire static load deformation, tire static temperature rise characteristics, and tire static load vibration mode characteristics.

[0136] The dynamic verification content of the tire finite element construction module includes: tire rolling pressure change, tire rolling load deformation, tire rolling load temperature rise characteristics, and tire rolling modal characteristics. Specific implementation method seven:

[0138] This embodiment of the calculation system for the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions differs from specific embodiments five or six in that the tire finite element model construction module defined by ambient temperature is affected by changes in ambient temperature, resulting in changes in the hardness coefficient, elastic modulus, density, and coefficients of various tire structural materials. Among these changes, the coefficients of tire materials include those of the tread layer, belt layer, inner liner, carcass, sidewall, triangular rubber, and steel cord structure. Detailed implementation method eight:

[0140] This embodiment of the calculation system for the impact of electric vehicle tire rolling resistance on energy consumption under cold-region operating conditions differs from specific embodiment seven in that the multi-factor coupled tire rolling state finite element model construction module, during the construction of the multi-factor coupled tire rolling state finite element model under low-temperature operating conditions,

[0141] A tire finite element model is constructed by coupling multiple factors. By setting the ambient temperature, road conditions, rolling speed, tire pressure, and vertical load separately, the realism of the tire finite element model is ensured to conform to the normal driving conditions of vehicles, and the constructed tire finite element model results are realistic.

[0142] The calculations involved in the finite element model include:

[0143] By using a mapping mechanism, the difference in strain energy density of each rubber material element at the same location on the tire is calculated, resulting in the cumulative strain energy density:

[0144] Δ=|e n+1,i -e n,i | (1)

[0145] Where e represents the element strain energy density, with units of J / mm². 3 n represents the tire block number, and i represents the tire block unit position number.

[0146] The total energy loss equals the work done by the tire rolling resistance. Due to possible simplifications in the model, the calculation of rolling resistance considers the average radius of each element. The energy loss of each rubber material element is:

[0147]

[0148] Among them, h i The energy loss of a rubber material unit is expressed in J; k represents the number of tire blocks, expressed in pieces; tanδ i This represents the material loss tangent for rubber material unit number i.

[0149] The tire rolling resistance is:

[0150]

[0151] Where R represents tire rolling resistance, in N; m represents the total number of rubber material units, in units; r represents the radius of the longitudinal section of the tire containing the rubber material unit numbered i, in mm; V i This represents the volume of the rubber material unit numbered i when it rotates around a radius of r in one revolution, in mm. 3 ;

[0152] The tire rolling resistance coefficient f is:

[0153] f = R / F v (4)

[0154] F v This indicates the vertical load on the tire, measured in N (newtons).

[0155] The energy consumption ratio of rolling resistance per kilometer is:

[0156]

[0157] Where q represents the percentage of energy consumed by rolling resistance per kilometer, expressed as a percentage; Q represents the total energy consumed per kilometer of electric vehicle driving, in mJ. Specific implementation method nine:

[0159] This embodiment of the apparatus for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions includes:

[0160] processor;

[0161] A memory in which executable instructions of the processor are stored;

[0162] The processor is configured to execute steps of a method for calculating the impact of tire rolling resistance on energy consumption of electric vehicles based on cold-region operating conditions by executing the executable instructions. Specific Implementation Method Ten:

[0164] This embodiment provides a computer-readable storage medium for storing a program that, when executed, implements the steps of a method for calculating the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions.

[0165] An implementation of the present invention of a method for calculating the impact of electric vehicle tire rolling resistance on energy consumption under cold-region operating conditions:

[0166] This embodiment uses a certain electric vehicle model as an example, with a battery capacity of 258.48 × 10⁻⁶. 9 mJ, with a range of 520km and an average energy consumption of 4.97×10 mJ per kilometer. 8 mJ. The reduction in tire rolling resistance at low temperatures affects the driving range of electric vehicles.

[0167]

[0168] Where S represents the reduction in mileage of electric vehicles, in km; h represents the measurement coefficient; and g represents the total energy consumption of electric vehicles, in mJ.

[0169] The cumulative strain energy density Δ of the rubber material unit is calculated using equation (1), and the energy loss h of each rubber material unit is calculated using equation (2). i The tire rolling resistance R and tire rolling resistance coefficient f are calculated by equations (3) and (4), the energy consumption ratio q of tire rolling resistance per kilometer is calculated by equation (5), and the range loss S of electric vehicle is calculated by equation (6).

[0170] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for calculating the impact of tire rolling resistance on energy consumption of an electric vehicle based on cold-weather conditions, characterized by: The method is realized by the following steps: Step one, by verifying the tire statics and dynamics in the process of tire rolling, a tire finite element model is constructed; Step two, by changing different low temperatures and different low temperature tire structure material coefficients, a tire finite element model defined by environmental temperature is constructed; Step three, by changing different road conditions and different road friction coefficients, a tire finite element model defined by driving road conditions is constructed; Step four, by changing different tire rolling speeds, the change of vehicle driving speed is simulated, and a tire finite element model defined by driving speed is constructed; Step five, by changing different tire pressure, the change of tire pressure in the process of vehicle driving is simulated, and a tire finite element model defined by tire pressure is constructed; Step six, by changing the vertical load acting on the center shaft, the change of load in the daily use of the vehicle is simulated, and a tire finite element model defined by vertical load is constructed; Step seven, by coupling environmental temperature, road conditions, driving speed, tire pressure, vertical load conditions, a tire rolling state finite element model under low temperature conditions is constructed; Step eight, by analyzing the results of the tire rolling state finite element model, the strain energy density cumulative value of all tire rubber material units is extracted, and all tire rubber material units are divided by angle and labeled; Step nine, by calculating the strain energy density cumulative value of all tire rubber material units, a tire rolling energy loss model is obtained; Step ten, by calculating the tire rolling energy loss and the energy consumption of the electric vehicle, the energy consumption caused by tire rolling is obtained; Step eleven, by the energy consumption caused by tire rolling per kilometer and the energy consumption of the electric vehicle, the influence of tire rolling resistance on energy consumption of the electric vehicle under low temperature conditions is obtained.

2. The method according to claim 1, characterized in that: In step one, the verification of tire statics and dynamics in the process of tire rolling includes: The verification of tire statics includes: tire static inflation deformation, tire static load deformation, tire static temperature rise characteristics, tire static load vibration modal characteristics; The verification of dynamics includes: tire rolling tire pressure change, tire rolling load deformation, tire rolling load temperature rise characteristics research, tire rolling modal characteristics research.

3. The method according to claim 1 or 2, characterized in that: In step two, due to the change of environmental temperature, the hardness coefficient, elastic modulus, density and tire material coefficient of each structure material of the tire affected by temperature change; Among them, the coefficient change of tire material includes the coefficient change of tread layer, belt layer, inner liner, carcass, sidewall, triangular rubber, steel cord structure.

4. The method according to claim 3, characterized in that: In step seven, by coupling environmental temperature, road conditions, driving speed, tire pressure, vertical load conditions, a tire rolling state finite element model under low temperature conditions is constructed; The calculations involved in the finite element model are: The difference between the rubber material unit strain energy density at the same position on the tire is taken by using the mapping mechanism, that is, the cumulative strain energy density is: The difference between the rubber material unit strain energy density at the same position on the tire is taken by using the mapping mechanism, that is, the cumulative strain energy density is: （1） wherein, e represents the unit cell strain energy density in J / mm 3 ; n represents the tire segment number, i represents the tire segment unit position number; The total energy loss is equal to the work done by the tire rolling resistance, and the energy loss of each rubber material unit is: （2） wherein, h i represents the energy loss of the rubber material unit, in J; k represents the number of tire segments, in a unit of 1; represents the material loss tangent value of the rubber material unit numbered i . The tire rolling resistance is: （3） in, R This indicates the rolling resistance of the tire, and the unit is N; m This indicates the total number of rubber material units, expressed in units of one. r The radius of the longitudinal section of the tire containing the rubber material unit numbered i is expressed in mm. V i Indicates the number is i rubber material unit r The volume of one revolution around the radius is expressed in mm. 3 ; Tire rolling resistance coefficient f is: f = R / F v （4） F v represents the vertical load received by the tire, and the unit is N; The energy consumption ratio of the rolling resistance per kilometer is: （5） wherein, q represents the energy consumption ratio of the rolling resistance per kilometer, expressed in %; Q represents the total energy consumed per kilometer of electric vehicle travel, in mJ.

5. A calculation system for the impact of electric vehicle tire rolling resistance on energy consumption based on cold-region operating conditions, characterized in that, The system is applied to the calculation method of the influence of the tire rolling resistance of an electric vehicle on energy consumption under cold working conditions according to any one of claims 1 to 4, and the system comprises: A tire finite element construction module for constructing a tire finite element model by verifying tire statics and dynamics during tire rolling; A tire finite element model construction module defined by environmental temperature for constructing a tire finite element model defined by environmental temperature by changing different low temperatures and different low-temperature tire material coefficients; A tire finite element model construction module defined by driving road conditions for constructing a tire finite element model defined by driving road conditions by changing different road conditions and different road friction coefficients; A tire finite element model construction module defined by driving speed for constructing a tire finite element model defined by driving speed by changing different tire rolling speeds to simulate changes in vehicle driving speed; A tire finite element model construction module defined by tire pressure for constructing a tire finite element model defined by tire pressure by changing different tire pressures to simulate changes in tire pressure during vehicle driving; A tire finite element model construction module defined by vertical load for constructing a tire finite element model defined by vertical load by changing the vertical load acting on the axle to simulate changes in load during daily use of the vehicle; A multi-factor coupled tire rolling state finite element model construction module for constructing a multi-factor coupled tire rolling state finite element model under low-temperature working conditions by coupling environmental temperature, road conditions, driving speed, tire pressure, and vertical load conditions; A block and label module for extracting the strain energy density cumulative values of all tire rubber material units and block-labeling all tire rubber material units by angle through analysis of the results of the tire rolling state finite element model; A tire rolling energy loss model calculation module for obtaining a tire rolling energy loss model by calculating the strain energy density cumulative values of all tire rubber material units; An energy consumption calculation module due to tire rolling for obtaining energy consumption due to tire rolling by calculating tire rolling energy loss and electric vehicle energy consumption; An influence determination module for obtaining the influence of tire rolling resistance on energy consumption of an electric vehicle under low-temperature working conditions by the energy consumption due to tire rolling per kilometer and the energy consumption of the electric vehicle.

6. The system for calculating the effect of rolling resistance on energy consumption of an electric vehicle tire based on cold weather conditions of claim 5, wherein: The tire finite element construction module verifies tire statics, including tire static inflation deformation, tire static load deformation, tire static temperature rise characteristics, and tire static load vibration modal characteristics; The tire finite element construction module verifies dynamics, including tire rolling tire pressure changes, tire rolling load deformation, tire rolling load temperature rise characteristics, and tire rolling modal characteristics.

7. The system for calculating the effect of rolling resistance on energy consumption of an electric vehicle tire based on cold weather conditions according to claim 5 or 6, wherein: The tire finite element model construction module defined by the ambient temperature, due to the change of ambient temperature, the hardness coefficient, the elastic modulus, the density and the tire material coefficient of each structure material of the tire affected by temperature change; wherein the tire material coefficient change includes the coefficient change of the tread layer, the belt layer, the inner liner, the carcass, the sidewall, the apex, and the steel cord structure.

8. The method according to claim 7, characterized in that: The multi-factor coupled tire rolling state finite element model construction module, in the process of constructing the multi-factor coupled tire rolling state finite element model under the low-temperature working condition, The finite element model involves the following calculations: The accumulated strain energy density is obtained by taking the difference between the strain energy densities of rubber material units at the same position on the tire by using the mapping mechanism, that is: The accumulated strain energy density is obtained by taking the difference between the strain energy densities of rubber material units at the same position on the tire by using the mapping mechanism, that is: （1） wherein, e represents the unit cell strain energy density in J / mm 3 ; n represents the tire block number, i represents the tire block unit position number; The total energy loss is equal to the work done by the tire rolling resistance, and the energy loss of each rubber material unit is: （2） wherein, h i represents the energy loss of the rubber material unit, in J; k represents the number of tire segments, in a unit of 1; represents the material loss tangent value of the rubber material unit numbered i . The tire rolling resistance is: （3） in, R This indicates the rolling resistance of the tire, and the unit is N; m This indicates the total number of rubber material units, expressed in units of one. r The radius of the longitudinal section of the tire containing the rubber material unit numbered i is expressed in mm. V i Indicates the number is i rubber material unit r The volume of one revolution around the radius is expressed in mm. 3 ; Tire rolling resistance coefficient f is: （4） F v represents the vertical load received by the tire, in N; The energy consumption ratio per kilometer of the rolling resistance is: （5） wherein, q represents the energy consumption ratio of the rolling resistance per kilometer, expressed in %; Q represents the total energy consumed per kilometer of electric vehicle travel, in mJ.

9. An apparatus for calculating the effect of rolling resistance of an electric vehicle tire on energy consumption based on cold region operating conditions, characterized by, It includes: A processor; A memory, wherein executable instructions of the processor are stored; The processor is configured to execute the executable instructions to perform the steps of the calculation method for the influence of the tire rolling resistance of the electric vehicle based on the cold region working condition on the energy consumption according to any one of claims 1 to 4.

10. A computer readable storage medium for storing a program, characterized in that, The program is executed to implement the steps of the calculation method for the influence of the tire rolling resistance of the electric vehicle based on the cold region working condition on the energy consumption according to any one of claims 1 to 4.

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