Vehicle all-condition pollutant emission evaluation method and system and storage medium

Abstract

The invention provides a vehicle all-condition pollutant emission evaluation method and system and a storage medium, and the method comprises the steps: dividing the operation mode of a vehicle into a cold start mode and a thermal stability operation mode according to the operation parameters in the vehicle driving process, and carrying out the secondary division of the thermal stability operation mode according to the engine load of the vehicle; according to the corresponding engine operation parameters and pollutant emission rates of the to-be-evaluated vehicle in the cold start mode and the thermostable operation mode, respectively obtaining a cold start pollutant emission value of the to-be-evaluated vehicle in the cold start mode and a thermostable operation pollutant emission value of the to-be-evaluated vehicle in the thermostable operation mode; and according to the cold start pollutant emission numerical value and the thermal stable operation pollutant emission numerical value, evaluating the all-condition pollutant emission of the to-be-evaluated vehicle. According to the method, all-working-condition pollutant emission test data are brought into the pollutant emission evaluation method by subdividing the vehicle operation modes, and emission control of vehicle cold start and thermostable operation at different stages is enhanced.

Description

Technical Field

[0001] This application relates to the field of vehicle supervision, and in particular to a method, system and storage medium for evaluating vehicle pollutant emissions under all working conditions. Background Art

[0002] In the process of vehicle supervision, the certification (or type inspection) of laboratory regulatory driving cycles is considered an important indicator for determining whether emissions meet the standards. Ideally, all kinds of operating conditions adopted in the design process of laboratory engine bench test conditions should continuously approach the true values of actual road driving. However, in order to ensure that the test results of different vehicles can be strictly compared horizontally, the boundary conditions during the test need to be strictly controlled. In recent years, more and more studies have found that during actual vehicle use, the emission results are very likely to exceed the limit requirements of laboratory type inspections. Therefore, in the process of vehicle emission supervision, relying solely on traditional laboratory engine bench certification tests often results in poor timeliness, accuracy or coverage. In order to effectively control emissions during actual vehicle driving, many countries have formulated actual road emission regulations represented by on-board testing (PEMS) in order to improve the feasibility and effectiveness of actual road emission supervision of in-use vehicles.

[0003] However, during the implementation of the PEMS standard, it has been found that there is still much room for improvement:

[0004] (1) When analyzing actual road PEMS tests, it is necessary to determine the work-based window size according to the cycle work of the engine bench standard test cycle. However, there are many sub-engine models in the same engine family in China, and the standard does not require all sub-engines to carry out type inspections based on the engine bench, resulting in the inability to obtain the standard cycle work of the sub-engines;

[0005] (2) Setting the minimum power requirement for the effective window is not conducive to the development of emission reduction technologies for low-speed and low-load conditions. For example, some vehicles (such as buses, sanitation vehicles, concrete trucks, engineering operation vehicles, garbage transport vehicles, etc.) are in a low-speed and low-load state for a long time, and the operation time accounts for more than 80%, but the emissions of these pollutants are not included in the control scope;

[0006] (3) The PEMS test standards of the United States, the European Union and China do not clearly include cold start in the emission management requirements. Although the Euro VI standard in stage E stipulates that effective emission assessment data begins to be generated when the coolant temperature reaches 30°C, and the latest US EPA standard stipulates that the coolant temperature at the start of the test should not be higher than 40°C. However, in a low-temperature environment, when the coolant temperature reaches 30-40°C, the emission control system has been significantly preheated, which will lead to an underestimation of cold start emissions under low-temperature conditions;

[0007] (4) The PEMS regulations in the EU and China have strict requirements for the proportion of driving cycles and vehicle speeds. There may be differences between the actual driving conditions of vehicles (including traffic conditions and vehicle load) and the PEMS test requirements, resulting in difficulties in directly applying PEMS data analysis methods to evaluate the emission compliance of in-use vehicles based on the data of on-board remote online monitoring (OBM). Summary of the Invention

[0008] To solve one of the above technical problems, the present invention provides a method, system, and storage medium for evaluating vehicle emissions under all driving conditions.

[0009] In the first aspect of the embodiments of the present invention, a method for evaluating vehicle emissions under all driving conditions is provided. The method includes:

[0010] Dividing the operating mode of the vehicle into a cold start mode and a hot stable operation mode according to the operating parameters during the vehicle driving process, and performing secondary division on the hot stable operation mode according to the engine load of the vehicle;

[0011] Obtaining the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the hot stable operation pollutant emission value of the vehicle to be evaluated in the hot stable operation mode respectively according to the engine operating parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the hot stable operation mode;

[0012] Evaluating the emissions of the vehicle to be evaluated under all driving conditions according to the cold start pollutant emission value and the hot stable operation pollutant emission value.

[0013] Preferably, the process of dividing the operating mode of the vehicle into a cold start mode and a hot stable operation mode according to the operating parameters during the vehicle driving process includes:

[0014] Setting the cold start start condition and end condition;

[0015] Dividing the operating mode between the cold start start condition and the end condition into the cold start mode;

[0016] Dividing the operating mode after the cold start end condition into the hot stable operation mode.

[0017] Preferably, the cold start start condition is that the differences between the engine coolant temperature, oil temperature, and the temperature of the emission after-treatment system and the ambient temperature are within a preset temperature difference range.

[0018] Preferably, the cold start end condition is:

[0019] The cumulative work done by the engine reaches a preset multiple of the standard cycle work,

[0020] or, the vehicle has been started for a preset start time,

[0021] Or, the engine coolant temperature reaches a preset temperature.

[0022] Preferably, the type of the thermal stable operation mode includes a plurality of sub-thermal stable operation modes, and the process of secondarily dividing the thermal stable operation mode according to the engine load of the vehicle includes:

[0023] Set at least one engine load limit value;

[0024] The thermal stable operation mode is divided into a plurality of sections by the at least one engine load limit value, and each section corresponds to a sub-thermal stable operation mode.

[0025] Preferably, when the cold start termination condition is that the vehicle starts for a preset start time or the engine coolant temperature reaches a preset temperature, the process of obtaining the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode according to the engine operation parameters and pollutant emission rate corresponding to the vehicle to be evaluated in the cold start mode includes:

[0026] Obtain the engine torque and engine speed of the vehicle to be evaluated in the cold start mode;

[0027] Obtain the engine test work done of the vehicle to be evaluated according to the engine torque and engine speed;

[0028] Obtain the cumulative pollutant emissions in the cold start mode according to the pollutant emission rate of the vehicle to be evaluated;

[0029] Obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode according to the engine test work done and the cumulative pollutant emissions in the cold start mode.

[0030] Preferably, when the cold start termination condition is that the cumulative engine work reaches a preset multiple of the standard cycle work, the process of obtaining the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode according to the engine operation parameters and pollutant emission rate corresponding to the vehicle to be evaluated in the cold start mode includes:

[0031] When the standard cycle work corresponding to the engine type of the vehicle to be evaluated is obtained through public information, obtain the cumulative pollutant emissions in the cold start mode according to the pollutant emission rate of the vehicle to be evaluated;

[0032] Obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode according to the standard cycle work obtained through public information and the cumulative pollutant emissions in the cold start mode;

[0033] When the standard cycle work corresponding to the engine type of the vehicle to be evaluated cannot be obtained through public information, based on the standard cycle work and rated power for which inspection information is publicly available for different engine types, a conversion coefficient between the standard cycle work and the rated power is calculated and obtained;

[0034] Based on the conversion coefficient and the engine rated power of the vehicle to be evaluated, the engine standard cycle work of the vehicle to be evaluated is obtained, and the engine test work is calculated based on the calculated engine standard cycle work and a preset multiple;

[0035] Based on the pollutant emission rate of the vehicle to be evaluated, the cumulative pollutant emissions in the cold start mode are obtained;

[0036] Based on the engine test work and the cumulative pollutant emissions in the cold start mode, the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is obtained.

[0037] Preferably, the process of obtaining the hot steady-state operation pollutant emission value of the vehicle to be evaluated in the hot steady-state operation mode based on the engine operation parameters and pollutant emission rate corresponding to the vehicle to be evaluated in the hot steady-state operation mode includes:

[0038] Set a time window and a time step;

[0039] Based on the time step, the engine operation parameters of the vehicle to be evaluated, and the pollutant emission rate, the average engine load, average pollutant emission rate, and average engine work for each time window are calculated and obtained;

[0040] Based on the average engine load, the sub-hot steady-state operation mode corresponding to each time window is determined;

[0041] Based on the average pollutant emission rate and average engine work for each time window, the hot steady-state operation pollutant emission value for each sub-hot steady-state operation mode is calculated and obtained.

[0042] Preferably, the process of evaluating the full operating condition pollutant emissions of the vehicle to be evaluated based on the cold start pollutant emission value and the hot steady-state operation pollutant emission value includes:

[0043] Based on the cold start pollutant emission value, the pollutant emissions of the vehicle to be evaluated in the cold start mode are evaluated;

[0044] Based on the hot steady-state operation pollutant emission value for each sub-hot steady-state operation mode, the pollutant emissions for each sub-hot steady-state operation mode are evaluated respectively.

[0045] Preferably, the process of evaluating the full operating condition pollutant emissions of the vehicle to be evaluated based on the cold start pollutant emission value and the hot steady-state operation pollutant emission value includes:

[0046] Obtain the actual travel characteristics of the vehicle to be evaluated;

[0047] Determine the cold start mode of the vehicle to be evaluated and the weighting coefficients corresponding to each sub-thermal stable operation mode according to the actual travel characteristics of the vehicle to be evaluated;

[0048] Multiply the cold start pollution emission value of the cold start mode of the vehicle to be evaluated or the thermal stable operation pollutant emission value of each sub-thermal stable operation mode by the weighting coefficient to obtain the weighted pollutant emission value corresponding to the cold start mode or each sub-thermal stable operation mode;

[0049] Perform a summation calculation on the weighted pollutant emission value of the cold start mode and the weighted pollutant emission values of each sub-thermal stable operation mode to obtain the full operating condition pollutant emission value of the vehicle to be evaluated.

[0050] The second aspect of the embodiment of the present invention provides a vehicle full operating condition pollutant emission evaluation system, and the system includes:

[0051] An operating mode division module, configured to divide the operating mode of the vehicle into a cold start mode and a thermal stable operation mode according to the operating parameters during the vehicle driving process, and perform secondary division on the thermal stable operation mode according to the engine load of the vehicle;

[0052] An operating mode pollutant emission calculation module, configured to obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the thermal stable operation pollutant emission value of the vehicle to be evaluated in the thermal stable operation mode respectively according to the engine operating parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the thermal stable operation mode;

[0053] A full operating condition pollutant emission calculation module, configured to obtain the full operating condition pollutant emission value of the vehicle to be evaluated according to the cold start pollutant emission value and the thermal stable operation pollutant emission value.

[0054] The third aspect of the embodiment of the present invention provides a computer storage medium, including computer instructions, and when the computer instructions run on an electronic device, the electronic device executes the method described in the first aspect of the embodiment of the present invention.

[0055] The beneficial effects of the present invention are as follows: By subdividing the vehicle operating mode, the present invention realizes incorporating the full operating condition pollutant emission test data into the pollutant emission evaluation method, which helps to strengthen the emission control of vehicle cold start and thermal stable operation in different stages. The present invention is not only applicable to on-road PEMS tests, but also can be applied to vehicle emission evaluation based on remote online monitoring. In addition, the present invention is also applicable to the analysis and evaluation of pollutant emission test data of other mobile sources such as heavy-duty vehicles, light-duty vehicles, and non-road mobile machinery, and has a very broad application prospect. Description of the Drawings

[0056] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0057] Figure 1 is a flowchart of the vehicle full - operating - condition pollutant emission evaluation method described in Embodiment 1 of the present invention;

[0058] Figure 2 is a schematic diagram of the division of the cold - start mode and the hot - stable - operation mode described in Embodiment 1 of the present invention;

[0059] Figure 3 is a schematic diagram of the relationship between the rated power of the engine and the WHTC standard cycle work described in Embodiment 1 of the present invention;

[0060] Figure 4 is a schematic diagram of the principle of the vehicle full - operating - condition pollutant emission evaluation system described in Embodiment 2 of the present invention. Detailed Embodiments

[0061] In order to make the technical solutions and advantages in the embodiments of the present application clearer, the following further describes the exemplary embodiments of the present application in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0062] Embodiment 1

[0063] As Figure 1 shown, this embodiment proposes a vehicle full - operating - condition pollutant emission evaluation method, which includes:

[0064] S101. Divide the operation mode of the vehicle into a cold - start mode and a hot - stable - operation mode according to the operation parameters during the vehicle driving process, and perform a secondary division on the hot - stable - operation mode according to the engine load of the vehicle.

[0065] Specifically, the pollutant emission evaluation method proposed in this embodiment can be applied to the analysis and evaluation of the full - operating - condition pollutant emission test data of other mobile sources, including heavy - duty vehicles, light - duty vehicles, non - road mobile machinery, etc. This embodiment takes heavy - duty vehicles as an example to elaborate on the vehicle full - operating - condition pollutant emission evaluation method.

[0066] In this embodiment, the operating modes of the vehicle are first divided to strengthen the emission control of cold start and low-load conditions. In this embodiment, the actual road data of the vehicle is divided into two major types of modes, namely, cold start mode and hot stable operation mode. For cold start, it generally refers to the stage before the engine reaches hot stable operation and before the aftertreatment system catalyst is activated. With the continuous upgrading and improvement of engine and exhaust aftertreatment technologies, controlling cold start emissions has become crucial for reducing vehicle pollutant emissions. In order to scientifically quantify the cold start emissions of actual road vehicles and more clearly distinguish the above-mentioned cold start mode and hot stable operation mode, this embodiment sets the starting conditions and ending conditions of cold start as the basis for defining the division of cold start mode and hot stable operation mode.

[0067] Specifically, this embodiment defines the cold start starting condition as the difference between the engine coolant temperature, oil temperature, and system equipment temperature and the ambient temperature within a preset temperature difference range. Generally speaking, when the vehicle is cold started, the engine coolant temperature, oil temperature, and the temperature of the emission aftertreatment system are close to the ambient temperature. Therefore, the preset temperature difference can be set within ±5°C, and this embodiment preferably uses ±2°C. After the vehicle has been cold started for a period of time, when the engine work reaches a certain value or the engine coolant temperature exceeds the ambient temperature by a large margin, it indicates that the vehicle has entered the next operating mode, that is, the hot stable operation mode. Therefore, this embodiment defines the cold start ending condition to include three situations, and any one of these three situations can be selected as the cold start ending condition. Specifically:

[0068] (1) The cumulative engine work reaches a preset work value

[0069] The preset work value can be set as a certain multiple of the standard cycle work, such as 1 times the standard cycle work. The standard cycle work usually refers to the work output by the engine through a complete working cycle. For engines that have undergone type inspection, the standard cycle work can be obtained from the publicly available data information. For engines that have not undergone type inspection, although the standard cycle work cannot be directly obtained, the cycle work of the engine WHTC standard test cycle can still be obtained through experiments or other means. This embodiment will elaborate in detail later. As Figure 2 shown, when the cumulative engine work reaches 1 times the standard cycle work, the vehicle operating mode changes from the cold start mode to the hot stable operation mode. Among them, curve 1 is the engine coolant temperature curve.

[0070] (2) The vehicle starts and reaches the preset start time

[0071] The preset start time for vehicle start can be obtained through experiments on the standard cycle duration of the engine and is usually set within 2000s. This embodiment preferably uses 1800s.

[0072] (3) The engine coolant temperature reaches the preset temperature

[0073] This preset temperature can also be determined according to experimental experience. In this embodiment, the preferred preset temperature is 70 °C.

[0074] For the thermal stable operation mode, in order to strengthen the emission control under low load conditions, in this embodiment, the thermal stable operation mode is further divided into multiple sub-thermal stable operation modes according to the engine load of the vehicle. Specifically: at least one engine load limit value is set, and the thermal stable operation mode is divided into multiple sections through the at least one engine load limit value, and each section corresponds to a sub-thermal stable operation mode. In this embodiment, taking the thermal stable operation mode being divided into three sub-thermal stable operation modes as an example for detailed description.

[0075] Two engine load limit values are set, namely the first engine load limit value and the second engine load limit value. When the actual engine load is less than the first engine load limit value, the type of the thermal stable operation mode is the first sub-thermal stable operation mode. When the actual engine load is greater than or equal to the first engine load limit value and less than the second engine load limit value, the type of the thermal stable operation mode is the second sub-thermal stable operation mode. When the actual engine load is greater than or equal to the second engine load limit value, the type of the thermal stable operation mode is the third sub-thermal stable operation mode. In this embodiment, the first engine load limit value is set to 6%, and the second engine load limit value is set to 20%, as shown in Table 1 below:

[0076] Table 1 Correspondence table between engine load and thermal stable operation mode

[0077]

[0078] As shown in Table 1, when the actual engine load is less than 6%, the type of the thermal stable operation mode is the first sub-thermal stable operation mode, that is, the idle mode. When the actual engine load is greater than or equal to 6% and less than 20%, the type of the thermal stable operation mode is the second sub-thermal stable operation mode, that is, the low load mode. When the actual engine load is greater than or equal to 20%, the type of the thermal stable operation mode is the third sub-thermal stable operation mode, that is, the medium and high load mode.

[0079] It should be noted that in this embodiment, the number of vehicle operation mode divisions can be further increased or decreased according to the specific requirements of vehicle pollutant emission evaluation. The above division made in this embodiment is only one example.

[0080] S102. Obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the thermal stable operation pollutant emission value of the vehicle to be evaluated in the thermal stable operation mode respectively according to the engine operation parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the thermal stable operation mode.

[0081] Specifically, after dividing the cold start mode and the hot stable operation mode, it is necessary to systematically calculate the pollutant emissions in the cold start mode and the hot stable operation mode. In this embodiment, different methods are used to calculate the pollutant emissions in the cold start mode and the hot stable operation mode.

[0082] When the vehicle to be evaluated is in the cold start mode, the cold start pollutant emission value is mainly obtained through the engine test work and the cumulative pollutant emissions in the cold start mode. Among them, the engine test work is calculated through the engine rated power and the conversion coefficient, specifically expressed as:

[0083] W WHTC = k × Power rated

[0084] Among them, W WHTC is specifically the cycle work of the WHTC standard test cycle of the engine of the vehicle to be evaluated, with the unit of kWh, and k is the conversion coefficient between the standard cycle work and the rated power of the engine. Power rated is the engine rated power.

[0085] For engines that have undergone type inspection, the standard cycle work can be obtained from the publicly available data information. That is, when the standard cycle work corresponding to the engine type of the vehicle to be evaluated can be directly obtained through public information, the cumulative pollutant emissions in the cold start mode are obtained according to the pollutant emission rate of the vehicle to be evaluated, and then the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is obtained based on the standard cycle work obtained from public information and the cumulative pollutant emissions in the cold start mode.

[0086] When the standard cycle work corresponding to the engine type of the vehicle to be evaluated cannot be obtained through public information, in this embodiment, the conversion coefficient k can be calculated through the standard cycle work and the rated power of the type inspection information of multiple different engine types. As Figure 3 shown, by analyzing the publicly available data of the type inspection information of more than 46,000 engine models, it is found that there is a good linear relationship between the engine rated power and its WHTC standard cycle work. Among them, k = 0.095, R 2 = 0.99. After determining the conversion coefficient k, the WHTC cycle work of the engine that has not undergone type inspection can be calculated according to this conversion coefficient k and the engine rated power of the vehicle to be evaluated. Then, the cumulative pollutant emissions in the cold start mode are obtained through the pollutant emission rate in the cold start mode of the vehicle to be evaluated. Finally, the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is obtained based on the engine test work and the cumulative pollutant emissions in the cold start mode.

[0087] Taking the cold start mode termination condition that the cumulative engine work reaches 1 times the standard cycle work as an example, the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is calculated through the following formula:

[0088]

[0089] Among them, EF i,Bin Cold is the specific emission in the cold start mode, that is, the cold start pollutant emission value, with the unit of mg / kWh (mass emission of gaseous pollutants and particulate matter) or # / kWh (particle number emission of particulate matter); m i,t is the emission rate of pollutant i at time t, with the unit of mg / s or # / s; T C is the duration of the cold start mode, with the unit of s.

[0090] If the cold start mode termination condition is that the vehicle starts to reach the preset start time or the engine coolant temperature reaches the preset temperature, the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is calculated through the following formula:

[0091]

[0092] Among them, EF i,Bin Cold is the specific emission in the cold start mode, that is, the cold start pollutant emission value, with the unit of mg / kWh (mass emission of gaseous pollutants and particulate matter) or # / kWh (particle number emission of particulate matter); m i,t is the emission rate of pollutant i at time t, with the unit of mg / s or # / s; T C is the duration of the cold start mode (that is, the duration of "the vehicle starts to reach the preset start time" or "the engine coolant temperature reaches the preset temperature"), with the unit of s; Torque t is the engine torque at time t in the cold start mode, with the unit of Nm; Speed t is the engine speed at time t in the cold start mode, with the unit of rpm.

[0093] When the vehicle to be evaluated is in the thermal stability operation mode, the thermal stability operation pollutant emission value is mainly obtained through the engine load, work done, and pollutant emission rate. First, set the time window and time step, as Figure 2 shown, based on the moving average method of a specific time window, the emission calculation of different sub-thermal stability operation modes is carried out. Figure 2 In, curve 2 is the specific emission curve of pollutants, and curve 3 is the pollutant emission rate curve. Among them, the time window can be set to 60s, 120s, or 300s, etc., and no special limitation is made in this embodiment. The time step can also be set according to the actual situation, for example, 1s.

[0094] After setting the time window and time step, calculate the average engine load, average pollutant emission rate, and average engine work for each time window, specifically as follows:

[0095] (1) Average engine load

[0096]

[0097] where Eng.Load j is the average engine load of time window j, %; Torque j,t is the engine torque at time t in time window j, with the unit of Nm; Speed j,t is the engine speed at time t in time window j, with the unit of rpm; Power rated is the rated power of the engine, with the unit of kW; T H is the length of the time window of the selected thermally stable operating mode, with the unit of s;

[0098] (2) Average pollutant emission rate

[0099]

[0100] where m i,j is the average emission rate of pollutant i in time window j, with the unit of mg / s or # / s; m i,j,t is the instantaneous emission rate of pollutant i at time t in time window j, with the unit of mg / s or # / s;

[0101] (3) Average engine work

[0102]

[0103] where W j is the average work done in time window j, with the unit of kWh;

[0104] After obtaining the average engine load for each time window, determine the corresponding sub-thermally stable operating mode for each time window according to the average engine load. Then, calculate the thermally stable operating pollutant emission values for each sub-thermally stable operating mode based on the average pollutant emission rate and average engine work of the time window corresponding to each sub-thermally stable operating mode, specifically as follows:

[0105]

[0106] where EF i,Bin xis the specific emission of pollutant i in sub-thermal stable operation mode Bin x, in mg / kWh or # / kWh; Bin x is the sub-thermal stable operation mode. Taking this embodiment as an example, it is the idle mode (BinIdle), low load mode (BinLow), and medium and high load mode (BinMed.&High); N is the total number of time windows of sub-thermal stable operation mode Bin x.

[0107] S103. Evaluate the full-condition pollutant emissions of the vehicle to be evaluated according to the cold start pollutant emission value and the thermal stable operation pollutant emission value.

[0108] Specifically, after obtaining the pollutant emission values of all cold start modes and thermal stable operation modes, obtain the actual travel characteristics of the vehicle to be evaluated, and calculate the weighted pollutant emission values of each operation mode through the travel characteristics of the vehicle to be evaluated to obtain the full-condition pollutant emission value of the vehicle to be evaluated:

[0109] EF i = w Cold × EF i,Bin Cold + w Idle × EF i,Bin Idle + w Low × EF i,Bin Low + w Med.&High × EF i,Bin Med.&High

[0110] Among them, EF i is the weighted specific emission of pollutant i, that is, the full-condition pollutant emission value of the vehicle to be evaluated, in mg / kWh or # / kWh; EF i,Bin Cold , EF i,Bin Idle , EF i,Bin Low and EF i,Bin Med.&High are the specific emissions of the cold start mode, thermal stable operation idle mode, low load mode, and medium and high load mode respectively, in mg / kWh or # / kWh; w Cold , w Idle , w Low and w Med.&High are the weighted coefficients of the cold start mode, thermal stable operation idle mode, low load mode, and medium and high load mode respectively, obtained through the investigation of the actual travel characteristics of the vehicle to be evaluated.

[0111] In this process, the pollution emission values of each operating mode of the vehicle to be evaluated (including the cold start mode and each sub-thermal stable operation mode) can be used to evaluate the pollutant emissions of each operating mode respectively. Specifically, the pollutant emissions of the vehicle to be evaluated in the cold start mode are evaluated according to the cold start pollutant emission values. The pollutant emissions of each sub-thermal stable operation mode are evaluated according to the thermal stable operation pollutant emission values of each sub-thermal stable operation mode. In this way, combined with the full operating condition pollutant emission values of the vehicle to be evaluated above, the pollutant emissions of each operating mode can be evaluated separately, or the pollutant emissions during the overall operation of the vehicle can be evaluated.

[0112] In this embodiment, by subdividing the vehicle operating modes, the full operating condition pollutant emission test data is incorporated into the pollutant emission evaluation method, strengthening the emission control of vehicle cold start and thermal stable operation in different stages. The present invention is not only applicable to the actual road PEMS test, but also can be applied to the vehicle emission evaluation based on remote online monitoring. In addition, this embodiment is also applicable to the analysis and evaluation of pollutant emission test data of other mobile sources, such as heavy-duty vehicles, light-duty vehicles, and non-road mobile machinery, and has a very broad application prospect.

[0113] Embodiment 2

[0114] As Figure 4 shown, corresponding to Embodiment 1, this embodiment proposes a vehicle full operating condition pollutant emission evaluation system, which includes:

[0115] An operating mode division module, configured to divide the operating mode of the vehicle into a cold start mode and a thermal stable operation mode according to the operating parameters during the vehicle driving process, and perform secondary division on the thermal stable operation mode according to the engine load of the vehicle;

[0116] An operating mode pollutant emission calculation module, configured to obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the thermal stable operation pollutant emission value of the vehicle to be evaluated in the thermal stable operation mode respectively according to the engine operating parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the thermal stable operation mode;

[0117] A full operating condition pollutant emission calculation module, configured to evaluate the full operating condition pollutant emissions of the vehicle to be evaluated according to the cold start pollutant emission value and the thermal stable operation pollutant emission value.

[0118] The working principle and implementation process of the vehicle full operating condition pollutant emission evaluation system proposed in this embodiment can refer to the content recorded in Embodiment 1, and will not be elaborated in this embodiment.

[0119] Embodiment 3

[0120] This embodiment provides a computer storage medium, including computer instructions. When the computer instructions run on an electronic device, the electronic device executes the following method:

[0121] Divide the operating mode of the vehicle into a cold start mode and a hot stable operation mode according to the operating parameters during the vehicle driving process, and perform a secondary division on the hot stable operation mode according to the engine load of the vehicle;

[0122] Obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the hot stable operation pollutant emission value of the vehicle to be evaluated in the hot stable operation mode respectively according to the engine operation parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the hot stable operation mode;

[0123] Evaluate the full-condition pollutant emissions of the vehicle to be evaluated according to the cold start pollutant emission value and the hot stable operation pollutant emission value.

[0124] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these changes and modifications.

Claims

1. A vehicle full-operation pollutant emission evaluation method, characterized in that: The method comprises: Dividing the operating mode of the vehicle into a cold start mode and a thermal steady operation mode according to the operating parameters of the vehicle during driving, and performing a secondary division on the thermal steady operation mode according to the engine load of the vehicle; According to the engine operating parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the hot steady operation mode, the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the hot steady operation pollutant emission value of the vehicle to be evaluated in the hot steady operation mode are obtained respectively; The full-operating-condition pollutant emissions of the vehicle to be evaluated are evaluated according to the cold-start pollutant emission values ​​and the hot-steady-state operation pollutant emission values.

2. The method according to claim 1, characterized in that The process of dividing the operating mode of the vehicle into a cold start mode and a thermal stable operating mode according to the operating parameters during the vehicle driving process includes: Set the cold start start and end conditions; Classifying the operation mode between the cold start starting condition and the termination condition as a cold start mode; Classifying the operation mode after the cold start termination condition as a thermal stable operation mode; The cold start starting condition is that the difference between the engine coolant temperature, the engine oil temperature, and the exhaust aftertreatment system temperature and the ambient temperature is within a preset temperature difference range; The cold start termination condition is: The accumulated work of the engine reaches the preset multiple of the standard cycle work. Or, the vehicle starts and reaches the preset start time, Or, the engine coolant temperature reaches the preset temperature.

3. The method according to claim 2, characterized in that The type of the thermal stable operation mode includes a plurality of sub-thermal stable operation modes, and the process of secondary dividing the thermal stable operation mode according to the engine load of the vehicle includes: setting at least one engine load limit value; The thermal stable operation mode is divided into a plurality of sections by the at least one engine load limit value, and each section corresponds to a sub-thermal stable operation mode.

4. The method according to claim 2, characterized in that: The cold start termination condition is when the vehicle starts and reaches a preset start time or the engine coolant temperature reaches a preset temperature. The process of obtaining the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode according to the engine operating parameters and pollutant emission rate corresponding to the vehicle to be evaluated in the cold start mode includes: Obtaining the engine torque and engine speed of the vehicle to be evaluated in a cold start mode; Obtaining the engine test work of the vehicle to be evaluated according to the engine torque and the engine speed; According to the pollutant emission rate of the vehicle to be evaluated, the cumulative pollutant emission under the cold start mode is obtained; The cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is obtained based on the engine test work and the cumulative pollutant emissions in the cold start mode.

5. The method according to claim 2, characterized in that: The cold start termination condition is when the accumulated work done by the engine reaches a preset multiple of the standard cycle work. The process of obtaining the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode according to the engine operating parameters and pollutant emission rate corresponding to the vehicle to be evaluated in the cold start mode includes: When the standard cycle work corresponding to the engine type of the vehicle to be evaluated is obtained through public information, the cumulative pollutant emissions under the cold start mode are obtained according to the pollutant emission rate of the vehicle to be evaluated; The cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is obtained based on the standard cycle work obtained from public information and the cumulative pollutant emission in the cold start mode; When the standard cycle power corresponding to the engine type of the vehicle to be evaluated cannot be obtained through public information, the conversion coefficient between the standard cycle power and the rated power is calculated based on the standard cycle power and rated power disclosed in the inspection information of different engine types; The standard cycle work of the engine of the vehicle to be evaluated is calculated based on the conversion coefficient and the rated power of the engine of the vehicle to be evaluated, and the test work of the engine is calculated based on the calculated standard cycle work of the engine and a preset multiple; According to the pollutant emission rate of the vehicle to be evaluated, the cumulative pollutant emission under the cold start mode is obtained; The cold start pollutant emission value of the vehicle to be evaluated in the cold start mode is obtained based on the engine test work and the cumulative pollutant emissions in the cold start mode.

6. The method according to claim 4 or 5, characterized in that: The process of obtaining the thermal stable operation pollutant emission value of the vehicle to be evaluated in the thermal stable operation mode according to the engine operation parameters and pollutant emission rate corresponding to the vehicle to be evaluated in the thermal stable operation mode includes: Set the time window and time step; The average engine load, average pollutant emission rate and average engine work of each time window are calculated according to the time step, the engine operating parameters of the vehicle to be evaluated and the pollutant emission rate; Determining a sub-thermal stable operation mode corresponding to each time window according to the average engine load; The thermal steady operation pollutant emission value of each sub-thermal steady operation mode is obtained based on the average pollutant emission rate and the average engine work in each time window.

7. The method according to claim 6, characterized in that The process of evaluating the full-operating-condition pollutant emissions of the vehicle to be evaluated according to the cold-start pollutant emission values ​​and the hot-steady-running pollutant emission values ​​includes: Evaluating the pollutant emissions of the vehicle to be evaluated in a cold start mode according to the cold start pollutant emission values; The pollutant emission of each sub-thermal stable operation mode is evaluated respectively according to the thermal stable operation pollutant emission value of each sub-thermal stable operation mode.

8. The method according to claim 7, characterized in that The process of evaluating the full-operating-condition pollutant emissions of the vehicle to be evaluated according to the cold-start pollutant emission values ​​and the hot-steady-running pollutant emission values ​​includes: Obtaining actual travel characteristics of the vehicle to be evaluated; Determining weighting coefficients corresponding to the cold start mode and each sub-thermal stable operation mode of the vehicle to be evaluated according to the actual travel characteristics of the vehicle to be evaluated; Multiplying the cold start pollutant emission value of the cold start mode of the vehicle to be evaluated or the thermal steady operation pollutant emission value of each sub-thermal steady operation mode by the weighting coefficient to obtain the weighted pollutant emission value corresponding to the cold start mode or each sub-thermal steady operation mode; The weighted pollutant emission value of the cold start mode and the weighted pollutant emission value of each sub-thermal steady operation mode are summed up to obtain the full-operating condition pollutant emission value of the vehicle to be evaluated.

9. A vehicle full-operation pollutant emission evaluation system, characterized in that: The system comprises: An operation mode division module, used for dividing the operation mode of the vehicle into a cold start mode and a thermal steady operation mode according to the operation parameters of the vehicle during driving, and performing a secondary division on the thermal steady operation mode according to the engine load of the vehicle; An operating mode pollutant emission calculation module is used to obtain the cold start pollutant emission value of the vehicle to be evaluated in the cold start mode and the hot stable operation pollutant emission value of the vehicle to be evaluated in the hot stable operation mode according to the engine operating parameters and pollutant emission rates corresponding to the vehicle to be evaluated in the cold start mode and the hot stable operation mode; The full-operating-condition pollutant emission calculation module is used to obtain the full-operating-condition pollutant emission value of the vehicle to be evaluated based on the cold-start pollutant emission value and the hot-steady-state operation pollutant emission value.

10. A computer storage medium, characterized in that: The method comprises computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the method according to any one of claims 1 to 8.

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