Control method and device for air coefficient of engine and vehicle

Abstract

The invention provides a control method and device for the air coefficient of an engine and a vehicle. The method comprises the steps that waste gas nitrogen oxide contents at multiple first collection moments within a first current timing time period are obtained, and a first waste gas nitrogen oxide content set is obtained; calculating a plurality of first waste gas nitrogen oxide content change rates according to the first waste gas nitrogen oxide content set; deleting the waste gas nitrogen oxide content of which the change rate of the first waste gas nitrogen oxide content is greater than a first change rate threshold and less than a second change rate threshold in the first waste gas nitrogen oxide content set to obtain a first waste gas nitrogen oxide content correction set, performing integral operation on the waste gas nitrogen oxide content of the first waste gas nitrogen oxide content correction set to obtain first nitrogen oxide specific emission; and under the condition that the first nitrogen oxide specific emission is larger than the first specific emission threshold value, the target value of the air coefficient is reduced, and the problem that according to an existing control method, due to inaccurate nitrogen oxide content detection, emission does not reach the standard is solved.

Description

Technical Field

[0001] This application relates to the field of engine control technology, and more specifically, to a method, apparatus, computer program product, and vehicle for controlling the air coefficient of an engine. Background Technology

[0002] To meet emission, diagnostic, and durability requirements, as well as the requirement to upload NOx signals, it is necessary to accurately detect the NOx content in the exhaust gas, thereby calculating the NOx specific emission and comparing it with the emission limit. By controlling the engine's aerodynamic coefficient to meet power requirements, it is necessary to ensure that the NOx specific emission is lower than the emission limit. However, existing NOx sensors have the problem of not being able to distinguish between NOx and NH3, which makes the NOx content detection inaccurate. This results in the calculated NOx specific emission being lower than the emission limit, while the actual NOx emission exceeds the standard. Summary of the Invention

[0003] The main objective of this application is to provide a method, device, computer program product, and vehicle for controlling the air coefficient of an engine, so as to at least solve the problem that the existing methods for controlling the air coefficient of an engine fail to meet emission standards due to inaccurate detection of nitrogen oxide content.

[0004] To achieve the above objectives, according to one aspect of this application, a method for controlling the air coefficient of an engine is provided. The control method is applied to an engine system including the engine and a three-way catalytic converter, the three-way catalytic converter being used to treat the exhaust gas of the engine. The control method includes: acquiring the exhaust gas nitrogen oxide content at multiple first sampling times within a first current timing period to obtain a first exhaust gas nitrogen oxide content set, wherein the first current timing period is the time interval between the last time the target value of the air coefficient was adjusted and the current time, and the exhaust gas nitrogen oxide content is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalytic converter; and calculating based on the first exhaust gas nitrogen oxide content set... Multiple first exhaust gas nitrogen oxide content change rates are calculated. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times. Exhaust gas nitrogen oxide content with first exhaust gas nitrogen oxide content change rates greater than a first change rate threshold and less than a second change rate threshold is deleted from the first exhaust gas nitrogen oxide content set to obtain a first exhaust gas nitrogen oxide content correction set. The exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content correction set is integrated to obtain a first nitrogen oxide specific emission. When the first nitrogen oxide specific emission is greater than the first specific emission threshold, the target value of the air coefficient is reduced.

[0005] Optionally, the method further includes: obtaining the nitrogen oxide content of exhaust gas at multiple second collection times within a second current timing period to obtain a second set of exhaust gas nitrogen oxide content, wherein the second current timing period is the time period between the last fault alarm and the current time; calculating multiple second exhaust gas nitrogen oxide content change rates based on the second set of exhaust gas nitrogen oxide content, wherein the second exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent second collection times to the time difference between the two adjacent second collection times; deleting exhaust gas nitrogen oxide content in the second set of exhaust gas nitrogen oxide content where the second exhaust gas nitrogen oxide content change rate is greater than the first change rate threshold and less than the second change rate threshold to obtain a second set of exhaust gas nitrogen oxide content correction; performing an integral operation on the exhaust gas nitrogen oxide content in the second set of exhaust gas nitrogen oxide content correction to obtain a second nitrogen oxide ratio emission; and issuing a fault alarm when the second nitrogen oxide ratio emission is greater than a second ratio emission threshold, wherein the second ratio emission threshold is greater than the first ratio emission threshold.

[0006] Optionally, performing an integral operation on the nitrogen oxide content of the first exhaust gas nitrogen oxide content correction set to obtain a first nitrogen oxide ratio emission includes: obtaining the nitrogen oxide content of the exhaust gas in the first exhaust gas nitrogen oxide content correction set that is less than or equal to the first rate of change threshold, to obtain a first steady-state low value set; obtaining the nitrogen oxide content of the exhaust gas in the first exhaust gas nitrogen oxide content correction set that is greater than or equal to the second rate of change threshold, to obtain a first peak value set; calculating the product of the first exhaust gas nitrogen oxide content in the first steady-state low value set and the exhaust gas flow rate at the corresponding first collection time, to obtain a first mass flow rate set, wherein the exhaust gas flow rate is the flow rate of the exhaust gas discharged by the engine; calculating the first peak value set... The product of the first exhaust gas nitrogen oxide content and the exhaust gas flow rate at the corresponding first collection time is used to obtain the second mass flow rate set. The first exhaust gas nitrogen oxide content in the first mass flow rate set is integrated along the time dimension to obtain the first nitrogen oxide emission. The first exhaust gas nitrogen oxide content in the second mass flow rate set is integrated along the time dimension to obtain the second nitrogen oxide emission. The sum of the first nitrogen oxide emission and the second nitrogen oxide emission is calculated to obtain the first total nitrogen oxide emission. The engine power at multiple first collection times within the first current timing period is integrated along the time dimension to obtain the first engine output power. The ratio of the first total nitrogen oxide emission to the first engine output power is calculated to obtain the first nitrogen oxide specific emission.

[0007] Optionally, deleting the nitrogen oxide contents in the first set of nitrogen oxide contents in the first exhaust gas from those with a change rate greater than a first change rate threshold and less than a second change rate threshold, to obtain a first set of nitrogen oxide contents in the exhaust gas, includes: obtaining the air coefficient at the first collection time corresponding to the first set of nitrogen oxide contents in the exhaust gas; obtaining the nitrogen oxide contents in the first set of nitrogen oxide contents corresponding to the air coefficient greater than 1, to obtain a first set of nitrogen oxide contents in the exhaust gas; deleting the nitrogen oxide contents in the first set of nitrogen oxide contents from the first set of nitrogen oxide contents from the first set of nitrogen oxide contents, to obtain a second set of nitrogen oxide contents in the exhaust gas; deleting the nitrogen oxide contents in the second set of nitrogen oxide contents from those with a change rate greater than the first change rate threshold and less than the second change rate threshold, to obtain a third set of nitrogen oxide contents in the exhaust gas; and combining the first set of nitrogen oxide contents in the exhaust gas and the third set of nitrogen oxide contents in the exhaust gas to form the first set of nitrogen oxide contents in the exhaust gas.

[0008] Optionally, before deleting the waste gas nitrogen oxide contents in the first waste gas nitrogen oxide content set whose first waste gas nitrogen oxide content change rate is greater than a first change rate threshold and less than a second change rate threshold, to obtain the first waste gas nitrogen oxide content correction set, the method further includes: obtaining the ammonia content of the waste gas treated by the three-way catalytic converter at multiple historical times; generating an ammonia content change curve based on the multiple historical times and the corresponding ammonia content; determining the maximum change rate of the ammonia content in all peak segments of the ammonia content change curve as the second change rate threshold, wherein the second change rate threshold is greater than the maximum change rate of the ammonia content; and determining the minimum change rate of the ammonia content in all peak segments as the first change rate threshold.

[0009] Optionally, the three-way catalytic converter includes a front three-way catalytic converter and a rear three-way catalytic converter through which the exhaust gas passes sequentially. Acquiring the exhaust gas nitrogen oxide content at multiple first sampling moments within a first current timing period to obtain a first exhaust gas nitrogen oxide content set includes: acquiring exhaust gas parameters, including exhaust gas temperature, exhaust gas flow rate, exhaust gas oxygen content, and the exhaust gas nitrogen oxide content; the exhaust gas flow rate being the flow rate of the exhaust gas discharged from the engine; the exhaust gas temperature being the temperature of the exhaust gas after treatment by the front three-way catalytic converter; and the exhaust gas oxygen content being the oxygen content of the exhaust gas before treatment by the front three-way catalytic converter; activating the closed-loop control function of the air coefficient and recording the activation time when all exhaust gas parameters are within their corresponding predetermined ranges; acquiring the exhaust gas nitrogen oxide content at multiple first sampling moments within the first current timing period, and deleting the exhaust gas nitrogen oxide content corresponding to the first sampling moments before the activation time to obtain the first exhaust gas nitrogen oxide content set.

[0010] Optionally, the engine system further includes a nitrogen oxide sensor for detecting the nitrogen oxide content in the exhaust gas. Before acquiring the nitrogen oxide content in the exhaust gas at multiple first sampling moments within a first current timing period to obtain a first set of nitrogen oxide content in the exhaust gas, the method further includes: acquiring the methane content in the exhaust gas; determining a corresponding correction coefficient based on the interval in which the methane content is located, wherein the correction coefficient corresponds one-to-one with the interval in which the methane content is located; and using the correction coefficient to correct the nitrogen oxide sensor so that the nitrogen oxide content in the exhaust gas output by the nitrogen oxide sensor is the product of the original detected value and the correction coefficient.

[0011] According to another aspect of this application, an air coefficient control device for an engine is provided. The control device is applied to an engine system, the engine system including the engine and a three-way catalytic converter, the three-way catalytic converter being used to treat the exhaust gas of the engine. The control device includes: a first acquisition unit, configured to acquire the exhaust gas nitrogen oxide content at multiple first sampling moments within a first current timing period, obtaining a first exhaust gas nitrogen oxide content set, wherein the current timing period is the time between the last time the target value of the air coefficient was adjusted and the current moment, and the exhaust gas nitrogen oxide content is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalytic converter; and a first calculation unit, configured to calculate multiple... A first exhaust gas nitrogen oxide content change rate, wherein the first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times; a second calculation unit, used to delete exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content set whose first exhaust gas nitrogen oxide content change rate is greater than a first change rate threshold and less than a second change rate threshold, to obtain a first exhaust gas nitrogen oxide content correction set, and to perform an integral operation on the exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content correction set to obtain a first nitrogen oxide ratio emission; an adjustment unit, used to reduce the target value of the air coefficient when the first nitrogen oxide ratio emission is greater than the first ratio emission threshold.

[0012] According to another aspect of this application, a computer program product is provided, comprising a computer program that, when executed by a processor, implements any of the methods described.

[0013] According to another aspect of this application, a vehicle is provided, comprising: an engine system, one or more processors, a memory, and one or more programs, wherein the engine system includes an engine and a three-way catalytic converter for treating exhaust gases from the engine, the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of the methods described.

[0014] By applying the technical solution of this application, in the above-mentioned method for controlling the air coefficient of an engine, experimental testing of the engine exhaust gas after treatment by the three-way catalytic converter revealed that the peak change rate of nitrogen oxide content was greater than that of ammonia content, and the peak change rate of ammonia content was greater than that of the steady-state change rate of nitrogen oxide content. By deleting exhaust gas nitrogen oxide content from the first exhaust gas nitrogen oxide content set whose first exhaust gas nitrogen oxide content change rate was greater than a first change rate threshold and less than a second change rate threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, improving the accuracy of the first nitrogen oxide ratio emission. Thus, when the first nitrogen oxide ratio emission is higher than the first ratio emission threshold, the target value of the air coefficient can be adjusted for closed-loop control to ensure emission compliance. This solves the problem in the prior art where the control method for the air coefficient of an engine fails to meet emission standards due to inaccurate detection of nitrogen oxide content. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1 A hardware structure block diagram of a mobile terminal for implementing a method for controlling the aerodynamic coefficient of an engine, according to an embodiment of this application, is shown.

[0017] Figure 2 A schematic flowchart of a method for controlling the air coefficient of an engine according to an embodiment of this application is shown.

[0018] Figure 3 A schematic diagram illustrating the change of NOx content over time detected by a NOx sensor according to an embodiment of this application is shown.

[0019] Figure 4 A schematic diagram showing the changes in NOx, NH3, and O2 content in exhaust gas over time, according to an embodiment of this application, is provided.

[0020] Figure 5 A structural block diagram of an exhaust gas treatment section of an engine system according to an embodiment of this application is shown;

[0021] Figure 6 A flowchart illustrating another method for controlling the air coefficient of an engine according to an embodiment of this application is shown.

[0022] Figure 7 A structural block diagram of an engine air coefficient control device provided according to an embodiment of this application is shown.

[0023] The above figures include the following reference numerals:

[0024] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 10. First acquisition unit; 20. First calculation unit; 30. Second calculation unit; 40. Adjustment unit. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:

[0029] DPF: Short for particulate filter, used to reduce particulate matter emissions in engine exhaust. It is used to capture particulate matter in exhaust gas. When the mass of captured particulate matter reaches a certain level, passive or active regeneration is required to restore the DPF's ability to capture particulate matter.

[0030] TWC: Three-way catalytic converter, a precious metal catalyst that can oxidize and reduce HC, CO and NOx. It is necessary to control the air-fuel ratio of the engine at the stoichiometric air-fuel ratio to achieve high conversion efficiency, such as 17.2 in CNG engines.

[0031] NOx sensor and cross-sensitivity: The NOx sensor can measure oxygen concentration and NOx concentration. NOx will oxidize NH3 into NOx, which can be measured and lead to an overestimation of the value.

[0032] Lambda control of a gas engine: lambda represents the ratio of the actual amount of air supplied to the theoretical amount of air required to burn fuel CH4. The gas engine is controlled according to the lambda=1 setting. An oxygen sensor is placed at the outlet of the engine turbocharger to calculate the actual value of engine combustion. The engine obtains the corrected amount of gas based on the deviation between this value and the set value through closed-loop control, so that the actual value follows the set value.

[0033] As described in the background section, existing methods for controlling the air coefficient of engines often fail to meet emission standards due to inaccurate detection of nitrogen oxide content. To address this issue, embodiments of this application provide a method, apparatus, computer program product, and vehicle for controlling the air coefficient of an engine.

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a method of controlling the aerodynamic coefficient of an engine according to an embodiment of the present invention. (See diagram below.) Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0036] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the engine aerodynamic coefficient control method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0037] This embodiment provides a method for controlling the air coefficient of an engine running on a mobile terminal, computer terminal, or similar computing device. The control method is applied to an engine system, which includes the engine and a three-way catalytic converter. The three-way catalytic converter is used to treat the exhaust gas of the engine. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0038] Figure 2 This is a flowchart of a method for controlling the aerodynamic coefficient of an engine according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0039] Step S201: Obtain the nitrogen oxide content of exhaust gas at multiple first collection times within the first current timing period to obtain the first set of nitrogen oxide content of exhaust gas. The first current timing period is the time period between the last time the target value of the air coefficient was adjusted and the current time. The nitrogen oxide content of exhaust gas is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalyst converter.

[0040] Specifically, the timing starts after each adjustment of the target value of the air coefficient and continues until the next adjustment of the target value of the air coefficient stops and the timing restarts. The current time can be any time within this time period. By obtaining the nitrogen oxide content of multiple exhaust gases collected between the time of the last adjustment of the target value of the air coefficient and the current time, the first set of nitrogen oxide content of exhaust gases can be obtained. The nitrogen oxide content of exhaust gases in the first set of nitrogen oxide content of exhaust gases corresponds one-to-one with the first collection time.

[0041] Step S202: Based on the above set of first exhaust gas nitrogen oxide content, multiple first exhaust gas nitrogen oxide content change rates are calculated. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times.

[0042] Specifically, for example, if two adjacent first sampling times are t1 and t2, the corresponding nitrogen oxide content in the exhaust gas is n1. NOx and n2 NOx The rate of change of nitrogen oxide content in the first waste gas corresponding to the nitrogen oxide content is |n2 NOx - n1 NOx | / (t2- t1), of course, the change rate of the first exhaust gas nitrogen oxide content corresponding to the first exhaust gas nitrogen oxide content is 0.

[0043] Step S203: Delete the nitrogen oxide contents in the first set of nitrogen oxide contents in the first exhaust gas where the rate of change of nitrogen oxide contents in the first exhaust gas is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain the first set of nitrogen oxide contents in ...

[0044] Specifically, by deleting the nitrogen oxide content of the first exhaust gas from the set of nitrogen oxide content where the rate of change of the first exhaust gas nitrogen oxide content is greater than the first rate of change threshold and less than the second rate of change threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, and the accurate first nitrogen oxide ratio emission can be calculated.

[0045] Step S204: If the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, reduce the target value of the air coefficient.

[0046] Specifically, if the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, it indicates that the emission is not up to standard. The target value of the air coefficient lambda is then reduced to decrease the NOx emission ratio.

[0047] In this embodiment, the above-mentioned method for controlling the air coefficient of an engine reveals that the peak change rate of nitrogen oxide content in the engine exhaust gas after treatment by the three-way catalytic converter is greater than that of ammonia content. Furthermore, the peak change rate of ammonia content is greater than the steady-state change rate of nitrogen oxide content. By deleting exhaust gas nitrogen oxide contents from the first exhaust gas nitrogen oxide content set whose change rate is greater than a first change rate threshold and less than a second change rate threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated. This improves the accuracy of the first nitrogen oxide ratio emission. Therefore, when the first nitrogen oxide ratio emission is higher than the first ratio emission threshold, the target value of the air coefficient lambda can be adjusted for closed-loop control to ensure emission compliance. This solves the problem in the prior art where inaccurate nitrogen oxide content detection leads to non-compliance with emission standards in the engine air coefficient control method.

[0048] In an optional embodiment, for diagnosing a three-way catalytic converter, the method further includes:

[0049] Step S301: Obtain the nitrogen oxide content of exhaust gas at multiple second collection times within the second current time period to obtain the second set of nitrogen oxide content of exhaust gas. The second current time period is the time period between the last fault alarm and the current time.

[0050] Step S302: Based on the above set of nitrogen oxide content in the second exhaust gas, a plurality of nitrogen oxide content change rates in the second exhaust gas are calculated. The nitrogen oxide content change rate in the second exhaust gas is the ratio of the absolute value of the difference between the nitrogen oxide content in the exhaust gas at two adjacent second collection times to the time difference between the two adjacent second collection times.

[0051] Step S303: Delete the nitrogen oxide contents in the second set of nitrogen oxide contents where the rate of change of nitrogen oxide contents is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain a second set of nitrogen oxide contents correction, and perform an integral operation on the nitrogen oxide contents in the second set of nitrogen oxide contents correction to obtain the second nitrogen oxide emission ratio.

[0052] Step S304: If the second nitrogen oxide emission ratio is greater than the second emission ratio threshold, a fault alarm is issued, wherein the second emission ratio threshold is greater than the first emission ratio threshold.

[0053] In the above embodiments, the calculation process for the second NOx ratio emission is the same as that for the first NOx ratio emission, except that the NOx content of the second set of exhaust gas NOx content is not exactly the same as that of the first set of exhaust gas NOx content. Each time a fault alarm is issued, the timing is reset. The second current timing period is the time period between the last fault alarm and the current time. The second NOx ratio emission is calculated from the exhaust gas NOx content collected during the second current timing period. If the second NOx ratio emission is greater than the second ratio emission threshold, it indicates that the three-way catalytic converter cannot effectively convert NOx. Therefore, a fault alarm is issued to remind relevant personnel to repair the three-way catalytic converter.

[0054] In an optional implementation, to calculate the nitrogen oxide emission ratio, step S203 above includes:

[0055] Step S2031: Obtain the nitrogen oxide content of the exhaust gas that is less than or equal to the first rate of change threshold in the first set of exhaust gas nitrogen oxide content correction, and obtain the first set of steady-state low values.

[0056] Step S2032: Obtain the nitrogen oxide content of the exhaust gas that is greater than or equal to the second rate of change threshold in the first set of exhaust gas nitrogen oxide content correction, and obtain the first peak set;

[0057] Step S2033: Calculate the product of the first exhaust gas nitrogen oxide content in the first steady-state low value set and the exhaust gas flow rate at the corresponding first collection time to obtain the first mass flow rate set, where the exhaust gas flow rate is the flow rate of the exhaust gas discharged by the engine.

[0058] Step S2034: Calculate the product of the nitrogen oxide content of the first exhaust gas in the first peak set and the exhaust gas flow rate at the corresponding first collection time to obtain the second mass flow rate set;

[0059] Step S2035: Integrate the nitrogen oxide content of the first exhaust gas in the first mass flow set along the time dimension to obtain the first nitrogen oxide emission; integrate the nitrogen oxide content of the first exhaust gas in the second mass flow set along the time dimension to obtain the second nitrogen oxide emission; calculate the sum of the first nitrogen oxide emission and the second nitrogen oxide emission to obtain the total first nitrogen oxide emission.

[0060] Step S2036: Integrate the engine power of multiple first acquisition moments within the first current timing period along the time dimension to obtain the first engine output power.

[0061] Step S2037: Calculate the ratio of the total first nitrogen oxide emissions to the output power of the first engine to obtain the first nitrogen oxide specific emissions.

[0062] In the above embodiments, it can be seen from the TWC emission control principle that, as Figure 3 As shown, NOx continuously exhibits peak values, rising from a lower steady-state value and then returning to a lower steady-state value. To differentiate between NOx and NH3 laterally, the peak and steady-state low values ​​of the first exhaust gas NOx content correction set are integrated separately. The rate of change of NOx is used to identify the peak values. Each peak value is integrated separately, denoted as M1, and the steady-state low value is denoted as S1. Engine power is calculated based on engine speed and torque. While the NOx content of the first exhaust gas NOx content correction set is being integrated, the power integration P1 is continuously performed. The first NOx emission ratio is calculated as (M1 + S1) / P1. Similarly, the peak and steady-state low values ​​of the first exhaust gas NOx content correction set are integrated separately, using the rate of change of NOx to identify the peak values. Each peak value is integrated separately, denoted as M2. While the NOx content of the second exhaust gas NOx content correction set is being integrated, the power integration P2 is continuously performed, denoted as S2. The second NOx emission ratio is calculated as (M2 + S2) / P1. P2, because it eliminates the influence of ammonia content on nitrogen oxide content measurement, makes the first nitrogen oxide emission ratio and the second nitrogen oxide emission ratio more accurate.

[0063] Of course, in order to avoid frequent adjustment of the target value of the air quality coefficient and misdiagnosis of faults, a power limit can be set. Only when the power integral P1 and the power integral P2 exceed the power limit will the first and second NOx emission ratios be calculated. This will prevent the NOx content data from being too low, which may lead to random errors and cause frequent adjustment of the target value of the air quality coefficient and misdiagnosis of faults.

[0064] To eliminate interference from NH3, in an optional implementation, step S203 further includes:

[0065] Step S2038: Obtain the air coefficient at the first sampling time corresponding to the first set of nitrogen oxide content in the first exhaust gas.

[0066] Step S2039: Obtain the nitrogen oxide content of the exhaust gas corresponding to the air coefficient greater than 1 in the first set of exhaust gas nitrogen oxide content, and obtain the first target set of exhaust gas nitrogen oxide content.

[0067] Step S2040: Delete the nitrogen oxide content of the first target nitrogen oxide content set in the first set of nitrogen oxide content ...

[0068] Step S2041: Delete the nitrogen oxide contents of the first nitrogen oxide contents in the second target nitrogen oxide content set where the change rate of the first nitrogen oxide contents is greater than the first change rate threshold and less than the second change rate threshold, to obtain the third target nitrogen oxide content set.

[0069] Step S2042: The first set of target exhaust gas nitrogen oxide content and the third set of target exhaust gas nitrogen oxide content are combined to form the first set of exhaust gas nitrogen oxide content correction.

[0070] In the above embodiments, the exhaust gas is analyzed for components, and the curves of NOx content, NH3 content, and O2 content are shown below. Figure 4 As shown, when the O2 content difference is less than 0, the air coefficient lambda is less than 1; when the O2 content difference is greater than 0, the air coefficient lambda is greater than 1. The NOx peak mainly occurs when the air coefficient lambda is greater than 1, while NH3 occurs when the air coefficient lambda is less than 1. Therefore, when the air coefficient lambda is less than 1, it is necessary to delete the above-mentioned first exhaust gas nitrogen oxide content change rate from the second target exhaust gas nitrogen oxide content set that is greater than the first change rate threshold and less than the second change rate threshold, to obtain the third target exhaust gas nitrogen oxide content set, in order to eliminate the interference of NH3 and ensure the accuracy of the calculation of the first and second nitrogen oxide ratio emissions.

[0071] To determine suitable first and second rate of change thresholds, in an optional embodiment, before deleting the nitrogen oxide contents in the first set of nitrogen oxide contents whose rate of change is greater than the first rate of change threshold and less than the second rate of change threshold, and obtaining the first set of corrected nitrogen oxide contents, the method further includes:

[0072] Step S401: Obtain the ammonia content of the exhaust gas after treatment by the above three-way catalyst converter at multiple historical moments.

[0073] Step S402: Generate an ammonia content change curve based on multiple historical moments and corresponding ammonia contents.

[0074] Step S403: The maximum rate of change of ammonia content in all peak segments of the ammonia content change curve is determined as the second rate of change threshold, and the second rate of change threshold is greater than the maximum rate of change of ammonia content.

[0075] Step S404: The minimum rate of change of the ammonia content in all the above-mentioned peak segments is determined as the first rate of change threshold.

[0076] In the above embodiments, the exhaust gas is analyzed for components, and the curves of NOx content, NH3 content, and O2 content are shown below. Figure 4 As shown, NOx still appears with sharp peaks, while the peaks of NH3 are relatively stable. The maximum rate of change of ammonia content in all peaks of the above ammonia content change curve is determined as the second rate of change threshold, and the minimum rate of change of ammonia content in all peaks is determined as the first rate of change threshold. Therefore, the rate of change of NH3 peaks is between the first and second rate of change thresholds. Thus, when the average rate of change is large, the peak can be added to the total NOx emissions. If the average rate of change is relatively stable, the peak can be discarded, thereby eliminating the influence of NH3 on NOx measurement and obtaining an accurate total NOx emission.

[0077] To ensure the accuracy of sensor detection, in one optional embodiment, the three-way catalytic converter includes a front three-way catalytic converter and a rear three-way catalytic converter through which the exhaust gas passes sequentially, and step S201 includes:

[0078] Step S2011: Obtain exhaust gas parameters, including exhaust gas temperature, exhaust gas flow rate, exhaust gas oxygen content and exhaust gas nitrogen oxide content. The exhaust gas flow rate is the flow rate of exhaust gas discharged from the engine. The exhaust gas temperature is the temperature of the exhaust gas after treatment by the three-way catalytic converter. The exhaust gas oxygen content is the oxygen content of the exhaust gas before treatment by the three-way catalytic converter.

[0079] Step S2012: When all the above exhaust gas parameters are within the corresponding predetermined range, activate the closed-loop control function of the above air coefficient and record the activation time.

[0080] Step S2013: Obtain the nitrogen oxide content of exhaust gas at multiple first collection times within the first current time period, and delete the nitrogen oxide content of exhaust gas corresponding to the first collection times before the activation time to obtain the set of nitrogen oxide content of exhaust gas.

[0081] In the above embodiments, such as Figure 5As shown, the exhaust gas treatment section of the engine system includes TWC1, TWC2, and DPF. TWC is used for the oxidation-reduction of HC, CO, and NOx, while DPF is used to capture PN generated from oil combustion in the engine, achieving high NOx, HC, and PN conversion rates. Both TWC1 and TWC2 are platinum, palladium, and rhodium noble metal catalysts, but their formulations differ. TWC1 is a high-noble-metal catalyst with a smaller support volume; compared to TWC2, the support volume ratio is between 0.5 and 0.67, and the total noble metal ratio is between 1.8 and 2.2. An oxygen sensor is installed before TWC1 for lambda-style closed-loop control of the engine. A temperature sensor is installed after TWC1 for aging correction and over-temperature protection. A NOx sensor is installed after TWC2 for closed-loop control and fault diagnosis. The DPF differential pressure sensor is used to detect the DPF differential pressure and estimate the ash content in the DPF. The sensor can then detect exhaust gas parameters. Since the sensor has an applicable range, when all parameters are within the preset range, the accuracy of the sensor detection is ensured by enabling En1 to be in an active state, allowing subsequent integration. This means that the nitrogen oxide content of the exhaust gas collected before activation needs to be deleted.

[0082] To eliminate interference from CH4 content, in an optional embodiment, the engine system further includes a nitrogen oxide sensor for detecting the nitrogen oxide content in the exhaust gas. Before acquiring the nitrogen oxide content in the exhaust gas at multiple first sampling times within a first current timing period to obtain a first set of exhaust gas nitrogen oxide contents, the method further includes:

[0083] Step S501: Obtain the methane content of the exhaust gas;

[0084] Step S502: Determine the corresponding correction coefficient based on the range of methane content, wherein the correction coefficient corresponds one-to-one with the range of methane content.

[0085] Step S503: The nitrogen oxide sensor is calibrated using the above-mentioned correction coefficient, so that the nitrogen oxide content in the exhaust gas output by the nitrogen oxide sensor is the product of the original detection value and the above-mentioned correction coefficient.

[0086] In the above implementation, the NOx sensor is first corrected to make its measurements more accurate. This primarily involves correcting the NOx sensor for CH4 content, as CH4 in the sensor can affect NO measurement, leading to higher readings. The correction is controlled within 5% to further ensure the accuracy of NOx sensor detection.

[0087] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the engine air coefficient control method of this application will be described in detail below with reference to specific embodiments.

[0088] This embodiment relates to a specific method for controlling the air coefficient of an engine, such as... Figure 6 As shown, it includes the following steps:

[0089] First, the NOx sensor was corrected to make its measurements more accurate. The main correction was made to adjust the CH4 content, as CH4 in the sensor can affect NO measurement, leading to higher readings. The correction was kept within 5%.

[0090] Then, integral calculations are performed on NOx and power: First, the integration enable condition is determined. This is based on the temperature after TWC1, exhaust gas flow rate, and pre- and post-oxygen signals (NOx sensor) to determine the upper and lower ranges. When all are within the preset range, enable En1 is activated, allowing subsequent integration. Based on the TWC emission control principles, it can be seen that... Figure 3 As shown, NOx continuously exhibits peak values, rising from a lower steady-state value and then returning to a lower steady-state value. To differentiate between NOx and NH3 laterally, peak values ​​and steady-state low values ​​are integrated separately. The rate of change of NOx is used to identify peak values, and each peak value is integrated separately. The peak value integral is denoted as M1 (another M2 is used for diagnostics), and the steady-state low value is denoted as S1 (another S2 is used for diagnostics). Engine power is calculated based on engine speed and torque. Power integration is continuously performed when En1 is activated. Two power variables are set: P1 for closed-loop control of NOx and P2 for NOx diagnostics. After completing one closed-loop control or diagnostic cycle, each integrator is reset to zero.

[0091] Next, we need to determine whether the peak integral of NOx is NOx or NH3. From Figure 4 It can be seen that NOx peaks mainly occur when lambda is greater than 1, while NH3 peaks occur when lambda is less than 1. Therefore, lambda is a primary criterion. Integration primarily uses the condition of lambda being greater than 1. Simultaneously, it can be observed that NOx also appears at high concentrations (lambda less than 1), mainly due to low NOx conversion efficiency. However, NOx still exhibits sharp peaks, while NH3 remains relatively stable. Therefore, the NOx change rate is further assessed. If the average change rate is large, the peak value can be added to the total NOx emissions; if the average change rate is relatively stable, the peak value is discarded. This method eliminates the influence of NH3 on NOx measurement, resulting in an accurate total NOx emission estimate.

[0092] When the power integral P1 exceeds the limit, the NOx emission ratio is calculated based on M1+S1 and P1. Compared with the emission limit (e.g., 0.2 g / kWh), if the limit is exceeded, the lambda setting is corrected to reduce the NOx emission ratio, and the power integral 1 is reset to start the calculation again.

[0093] When the power integral P2 exceeds the limit, the NOx emission ratio is calculated based on M2+S2 and P2. If the emission ratio is exceeded (e.g., 1.2 g / kWh), a fault is reported, and the power integral P2 is reset to restart the calculation.

[0094] This application also provides an engine air coefficient control device. It should be noted that the engine air coefficient control device of this application embodiment can be used to execute the engine air coefficient control method provided in this application embodiment. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0095] The following describes the control device for the air coefficient of an engine provided in the embodiments of this application. The control device is applied to an engine system, which includes the engine and a three-way catalytic converter. The three-way catalytic converter is used to treat the exhaust gas of the engine.

[0096] Figure 7 This is a schematic diagram of an engine air coefficient control device according to an embodiment of this application. Figure 7 As shown, the device includes:

[0097] The first acquisition unit 10 is used to acquire the nitrogen oxide content of exhaust gas at multiple first acquisition times within the first current timing period, and to obtain a first set of nitrogen oxide content of exhaust gas. The current timing period is the time period between the last time the target value of the air coefficient was adjusted and the current time. The nitrogen oxide content of exhaust gas is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalyst converter.

[0098] Specifically, the timing starts after each adjustment of the target value of the air coefficient and continues until the next adjustment of the target value of the air coefficient stops and the timing restarts. The current time can be any time within this time period. By obtaining the nitrogen oxide content of multiple exhaust gases collected between the time of the last adjustment of the target value of the air coefficient and the current time, the first set of nitrogen oxide content of exhaust gases can be obtained. The nitrogen oxide content of exhaust gases in the first set of nitrogen oxide content of exhaust gases corresponds one-to-one with the first collection time.

[0099] The first calculation unit 20 is used to calculate multiple first exhaust gas nitrogen oxide content change rates based on the above-mentioned first exhaust gas nitrogen oxide content set. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times.

[0100] Specifically, for example, if two adjacent first sampling times are t1 and t2, the corresponding nitrogen oxide content in the exhaust gas is n1. NOx and n2 NOx The rate of change of nitrogen oxide content in the first waste gas corresponding to the nitrogen oxide content is |n2 NOx - n1 NOx | / (t2- t1), of course, the change rate of the first exhaust gas nitrogen oxide content corresponding to the first exhaust gas nitrogen oxide content is 0.

[0101] The second calculation unit 30 is used to delete the nitrogen oxide content of the first exhaust gas from the first exhaust gas nitrogen oxide content set where the change rate of the first exhaust gas nitrogen oxide content is greater than the first change rate threshold and less than the second change rate threshold, to obtain the first exhaust gas nitrogen oxide content correction set, and to perform an integral operation on the nitrogen oxide content of the first exhaust gas nitrogen oxide content correction set to obtain the first nitrogen oxide emission ratio.

[0102] Specifically, by deleting the nitrogen oxide content of the first exhaust gas from the set of nitrogen oxide content where the rate of change of the first exhaust gas nitrogen oxide content is greater than the first rate of change threshold and less than the second rate of change threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, and the accurate first nitrogen oxide ratio emission can be calculated.

[0103] The adjustment unit 40 is used to reduce the target value of the air coefficient when the first nitrogen oxide emission ratio is greater than the first emission ratio threshold.

[0104] Specifically, if the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, it indicates that the emission is not up to standard. The target value of the air coefficient lambda is then reduced to decrease the NOx emission ratio.

[0105] In this embodiment, the control device for the air coefficient of the engine described above shows that the peak change rate of nitrogen oxide content in the engine exhaust gas after treatment by the three-way catalytic converter is greater than that of ammonia content. Furthermore, the peak change rate of ammonia content is greater than the steady-state change rate of nitrogen oxide content. By deleting exhaust gas nitrogen oxide contents from the first exhaust gas nitrogen oxide content set whose first change rate is greater than a first change rate threshold and less than a second change rate threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated. This improves the accuracy of the first nitrogen oxide ratio emission. Therefore, when the first nitrogen oxide ratio emission is higher than the first ratio emission threshold, the target value of the air coefficient lambda can be adjusted for closed-loop control to ensure emission compliance. This solves the problem in the prior art where inaccurate nitrogen oxide content detection leads to non-compliance with emission standards in the engine air coefficient control method.

[0106] In an optional embodiment for diagnosing a three-way catalytic converter, the above-mentioned apparatus further includes:

[0107] The second acquisition unit is used to acquire the nitrogen oxide content of exhaust gas at multiple second acquisition times within the second current timing period, and obtain the second nitrogen oxide content set of exhaust gas. The second current timing period is the time period between the last fault alarm and the current time.

[0108] The third calculation unit is used to calculate multiple rates of change of nitrogen oxide content in the second exhaust gas based on the above-mentioned set of nitrogen oxide content in the second exhaust gas. The rate of change of nitrogen oxide content in the second exhaust gas is the ratio of the absolute value of the difference between the nitrogen oxide content in the exhaust gas at two adjacent second collection times to the time difference between the two adjacent second collection times.

[0109] The fourth calculation unit is used to delete the nitrogen oxide contents of the second exhaust gas from the set of nitrogen oxide contents of the second exhaust gas where the rate of change of the nitrogen oxide contents of the second exhaust gas is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain a set of corrected nitrogen oxide contents of the second exhaust gas, and to perform an integral operation on the nitrogen oxide contents of the second set of corrected nitrogen oxide contents of the second exhaust gas to obtain the second nitrogen oxide emission ratio.

[0110] The transmitting unit is configured to issue a fault alarm when the second nitrogen oxide emission ratio is greater than the second emission ratio threshold, wherein the second emission ratio threshold is greater than the first emission ratio threshold.

[0111] In the above embodiments, the calculation process for the second NOx ratio emission is the same as that for the first NOx ratio emission, except that the NOx content of the second set of exhaust gas NOx content is not exactly the same as that of the first set of exhaust gas NOx content. Each time a fault alarm is issued, the timing is reset. The second current timing period is the time period between the last fault alarm and the current time. The second NOx ratio emission is calculated from the exhaust gas NOx content collected during the second current timing period. If the second NOx ratio emission is greater than the second ratio emission threshold, it indicates that the three-way catalytic converter cannot effectively convert NOx. Therefore, a fault alarm is issued to remind relevant personnel to repair the three-way catalytic converter.

[0112] In one optional embodiment, to calculate the nitrogen oxide emission ratio, the second calculation unit includes:

[0113] The first acquisition module is used to acquire the nitrogen oxide content of the exhaust gas that is less than or equal to the first rate of change threshold in the first exhaust gas nitrogen oxide content correction set, and to obtain the first steady-state low value set.

[0114] The second acquisition module is used to acquire the nitrogen oxide content of the exhaust gas that is greater than or equal to the second rate of change threshold in the first exhaust gas nitrogen oxide content correction set, and to obtain the first peak set.

[0115] The first calculation module is used to calculate the product of the nitrogen oxide content of the first exhaust gas in the first steady-state low value set and the exhaust gas flow rate at the corresponding first collection time to obtain the first mass flow rate set, wherein the exhaust gas flow rate is the flow rate of the exhaust gas discharged by the engine.

[0116] The second calculation module is used to calculate the product of the nitrogen oxide content of the first exhaust gas in the first peak set and the exhaust gas flow rate at the corresponding first collection time to obtain the second mass flow rate set.

[0117] The third calculation module is used to integrate the nitrogen oxide content of the first exhaust gas in the first mass flow set along the time dimension to obtain the first nitrogen oxide emission amount, integrate the nitrogen oxide content of the first exhaust gas in the second mass flow set along the time dimension to obtain the second nitrogen oxide emission amount, and calculate the sum of the first nitrogen oxide emission amount and the second nitrogen oxide emission amount to obtain the total first nitrogen oxide emission amount.

[0118] The fourth calculation module is used to integrate the engine power of multiple first acquisition moments within the first current timing period along the time dimension to obtain the first engine output power.

[0119] The fifth calculation module is used to calculate the ratio of the total first nitrogen oxide emissions to the output power of the first engine, and to obtain the first nitrogen oxide specific emissions.

[0120] In the above embodiments, it can be seen from the TWC emission control principle that, as Figure 3 As shown, NOx continuously exhibits peak values, rising from a lower steady-state value and then returning to a lower steady-state value. To differentiate between NOx and NH3 laterally, the peak and steady-state low values ​​of the first exhaust gas NOx content correction set are integrated separately. The rate of change of NOx is used to identify the peak values. Each peak value is integrated separately, denoted as M1, and the steady-state low value is denoted as S1. Engine power is calculated based on engine speed and torque. While the NOx content of the first exhaust gas NOx content correction set is being integrated, the power integration P1 is continuously performed. The first NOx emission ratio is calculated as (M1 + S1) / P1. Similarly, the peak and steady-state low values ​​of the first exhaust gas NOx content correction set are integrated separately, using the rate of change of NOx to identify the peak values. Each peak value is integrated separately, denoted as M2. While the NOx content of the second exhaust gas NOx content correction set is being integrated, the power integration P2 is continuously performed, denoted as S2. The second NOx emission ratio is calculated as (M2 + S2) / P1. P2, because it eliminates the influence of ammonia content on nitrogen oxide content measurement, makes the first nitrogen oxide emission ratio and the second nitrogen oxide emission ratio more accurate.

[0121] Of course, in order to avoid frequent adjustment of the target value of the air quality coefficient and misdiagnosis of faults, a power limit can be set. Only when the power integral P1 and the power integral P2 exceed the power limit will the first and second NOx emission ratios be calculated. This will prevent the NOx content data from being too low, which may lead to random errors and cause frequent adjustment of the target value of the air quality coefficient and misdiagnosis of faults.

[0122] To eliminate interference from NH3, in one optional implementation, the second computing unit further includes:

[0123] The third acquisition module is used to acquire the air coefficient corresponding to the first acquisition time of the first set of nitrogen oxide contents in the first exhaust gas.

[0124] The fourth acquisition module is used to acquire the nitrogen oxide content of the exhaust gas corresponding to the air coefficient greater than 1 in the first set of exhaust gas nitrogen oxide content, and to obtain the first target set of exhaust gas nitrogen oxide content.

[0125] The first deletion module is used to delete the nitrogen oxide content of the first target nitrogen oxide content set of the first set of nitrogen oxide content in ...

[0126] The second deletion module is used to delete the nitrogen oxide contents of the first nitrogen oxide contents of the first exhaust gas from the second target nitrogen oxide content set where the change rate of the nitrogen oxide contents of the first exhaust gas is greater than the first change rate threshold and less than the second change rate threshold, so as to obtain the third target nitrogen oxide content set.

[0127] The combination module is used to combine the above-mentioned first target exhaust gas nitrogen oxide content set and the above-mentioned third target exhaust gas nitrogen oxide content set to form the above-mentioned first exhaust gas nitrogen oxide content correction set.

[0128] In the above embodiments, the exhaust gas is analyzed for components, and the curves of NOx content, NH3 content, and O2 content are shown below. Figure 4 As shown, when the O2 content difference is less than 0, the air coefficient lambda is less than 1; when the O2 content difference is greater than 0, the air coefficient lambda is greater than 1. The NOx peak mainly occurs when the air coefficient lambda is greater than 1, while NH3 occurs when the air coefficient lambda is less than 1. Therefore, when the air coefficient lambda is less than 1, it is necessary to delete the above-mentioned first exhaust gas nitrogen oxide content change rate from the second target exhaust gas nitrogen oxide content set that is greater than the first change rate threshold and less than the second change rate threshold, to obtain the third target exhaust gas nitrogen oxide content set, in order to eliminate the interference of NH3 and ensure the accuracy of the calculation of the first and second nitrogen oxide ratio emissions.

[0129] To determine suitable first and second rate of change thresholds, in one optional embodiment, the apparatus further includes:

[0130] The third acquisition unit is used to acquire the ammonia content of the exhaust gas after treatment by the three-way catalyst converter at multiple historical moments before deleting the exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content set where the change rate of the first exhaust gas nitrogen oxide content is greater than the first change rate threshold and less than the second change rate threshold, and obtaining the first exhaust gas nitrogen oxide content correction set.

[0131] The generation unit is used to generate an ammonia content change curve based on multiple historical moments and the corresponding ammonia content.

[0132] The first determining unit is used to determine the maximum rate of change of ammonia content in all peak segments of the ammonia content change curve as the second rate of change threshold, wherein the second rate of change threshold is greater than the maximum rate of change of ammonia content.

[0133] The second determining unit is used to determine the minimum rate of change of the ammonia content in all the above-mentioned peak segments as the first rate of change threshold.

[0134] In the above embodiments, the exhaust gas is analyzed for components, and the curves of NOx content, NH3 content, and O2 content are shown below. Figure 4 As shown, NOx still appears with sharp peaks, while the peaks of NH3 are relatively stable. The maximum rate of change of ammonia content in all peaks of the above ammonia content change curve is determined as the second rate of change threshold, and the minimum rate of change of ammonia content in all peaks is determined as the first rate of change threshold. Therefore, the rate of change of NH3 peaks is between the first and second rate of change thresholds. Thus, when the average rate of change is large, the peak can be added to the total NOx emissions. If the average rate of change is relatively stable, the peak can be discarded, thereby eliminating the influence of NH3 on NOx measurement and obtaining an accurate total NOx emission.

[0135] To ensure the accuracy of sensor detection, in one optional embodiment, the three-way catalytic converter includes a front three-way catalytic converter and a rear three-way catalytic converter through which the exhaust gas passes sequentially, and the first acquisition unit includes:

[0136] The fifth acquisition module is used to acquire exhaust gas parameters, including exhaust gas temperature, exhaust gas flow rate, exhaust gas oxygen content and exhaust gas nitrogen oxide content. The exhaust gas flow rate is the flow rate of exhaust gas discharged from the engine, the exhaust gas temperature is the temperature of exhaust gas after treatment by the three-way catalytic converter, and the exhaust gas oxygen content is the oxygen content of exhaust gas before treatment by the three-way catalytic converter.

[0137] The activation module is used to activate the closed-loop control function of the air coefficient and record the activation time when all the above exhaust gas parameters are within the corresponding predetermined range.

[0138] The sixth acquisition module is used to acquire the nitrogen oxide content of exhaust gas at multiple first acquisition times within the first current time period, and delete the nitrogen oxide content of exhaust gas corresponding to the first acquisition times before the activation time to obtain the set of nitrogen oxide content of exhaust gas.

[0139] In the above embodiments, such as Figure 5As shown, the exhaust gas treatment section of the engine system includes TWC1, TWC2, and DPF. TWC is used for the oxidation-reduction of HC, CO, and NOx, while DPF is used to capture PN generated from oil combustion in the engine, achieving high NOx, HC, and PN conversion rates. Both TWC1 and TWC2 are platinum, palladium, and rhodium noble metal catalysts, but their formulations differ. TWC1 is a high-noble-metal catalyst with a smaller support volume; compared to TWC2, the support volume ratio is between 0.5 and 0.67, and the total noble metal ratio is between 1.8 and 2.2. An oxygen sensor is installed before TWC1 for lambda-style closed-loop control of the engine. A temperature sensor is installed after TWC1 for aging correction and over-temperature protection. A NOx sensor is installed after TWC2 for closed-loop control and fault diagnosis. The DPF differential pressure sensor is used to detect the DPF differential pressure and estimate the ash content in the DPF. The sensor can then detect exhaust gas parameters. Since the sensor has an applicable range, when all parameters are within the preset range, the accuracy of the sensor detection is ensured by enabling En1 to be in an active state, allowing subsequent integration. This means that the nitrogen oxide content of the exhaust gas collected before activation needs to be deleted.

[0140] To eliminate interference from CH4 content, in an optional embodiment, the above-mentioned device further includes:

[0141] The fourth acquisition unit is used in the engine system, which also includes a nitrogen oxide sensor. The nitrogen oxide sensor is used to detect the nitrogen oxide content in the exhaust gas. Before acquiring the nitrogen oxide content in the exhaust gas at multiple first acquisition times within the first current timing period and obtaining the first set of nitrogen oxide content in the exhaust gas, the methane content in the exhaust gas is acquired.

[0142] The third determining unit is used to determine the corresponding correction coefficient based on the range of the methane content, and the correction coefficient corresponds one-to-one with the range of the methane content.

[0143] The calibration unit is used to calibrate the nitrogen oxide sensor using the aforementioned calibration coefficient, so that the nitrogen oxide content in the exhaust gas output by the nitrogen oxide sensor is the product of the original detection value and the aforementioned calibration coefficient.

[0144] In the above implementation, the NOx sensor is first corrected to make its measurements more accurate. This primarily involves correcting the NOx sensor for CH4 content, as CH4 in the sensor can affect NO measurement, leading to higher readings. The correction is controlled within 5% to further ensure the accuracy of NOx sensor detection.

[0145] The aforementioned engine aerodynamic coefficient control device includes a processor and a memory. The first acquisition unit, first calculation unit, second calculation unit, and adjustment unit are all stored as program units in the memory. The processor executes these program units stored in the memory to achieve the corresponding functions. All of the above modules reside in the same processor; alternatively, the modules may be located in different processors in any combination.

[0146] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and adjusting kernel parameters can address the problem of inaccurate nitrogen oxide detection leading to emissions non-compliance in existing engine aerodynamic control methods.

[0147] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0148] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform a method for controlling the air coefficient of the engine.

[0149] Specifically, methods for controlling the engine's aerodynamic coefficient include:

[0150] Step S201: Obtain the nitrogen oxide content of exhaust gas at multiple first collection times within the first current timing period to obtain the first set of nitrogen oxide content of exhaust gas. The first current timing period is the time period between the last time the target value of the air coefficient was adjusted and the current time. The nitrogen oxide content of exhaust gas is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalyst converter.

[0151] Specifically, the timing starts after each adjustment of the target value of the air coefficient and continues until the next adjustment of the target value of the air coefficient stops and the timing restarts. The current time can be any time within this time period. By obtaining the nitrogen oxide content of multiple exhaust gases collected between the time of the last adjustment of the target value of the air coefficient and the current time, the first set of nitrogen oxide content of exhaust gases can be obtained. The nitrogen oxide content of exhaust gases in the first set of nitrogen oxide content of exhaust gases corresponds one-to-one with the first collection time.

[0152] Step S202: Based on the above set of first exhaust gas nitrogen oxide content, multiple first exhaust gas nitrogen oxide content change rates are calculated. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times.

[0153] Specifically, for example, if two adjacent first sampling times are t1 and t2, the corresponding nitrogen oxide content in the exhaust gas is n1. NOx and n2 NOx The rate of change of nitrogen oxide content in the first waste gas corresponding to the nitrogen oxide content is |n2 NOx - n1 NOx | / (t2- t1), of course, the change rate of the first exhaust gas nitrogen oxide content corresponding to the first exhaust gas nitrogen oxide content is 0.

[0154] Step S203: Delete the nitrogen oxide contents in the first set of nitrogen oxide contents in the first exhaust gas where the rate of change of nitrogen oxide contents in the first exhaust gas is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain the first set of nitrogen oxide contents in ...

[0155] Specifically, by deleting the nitrogen oxide content of the first exhaust gas from the set of nitrogen oxide content where the rate of change of the first exhaust gas nitrogen oxide content is greater than the first rate of change threshold and less than the second rate of change threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, and the accurate first nitrogen oxide ratio emission can be calculated.

[0156] Step S204: If the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, reduce the target value of the air coefficient.

[0157] Specifically, if the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, it indicates that the emission is not up to standard. The target value of the air coefficient lambda is then reduced to decrease the NOx emission ratio.

[0158] This invention provides a processor for running a program, wherein the program executes a method for controlling the air coefficient of the engine.

[0159] Specifically, methods for controlling the engine's aerodynamic coefficient include:

[0160] Step S201: Obtain the nitrogen oxide content of exhaust gas at multiple first collection times within the first current timing period to obtain the first set of nitrogen oxide content of exhaust gas. The first current timing period is the time period between the last time the target value of the air coefficient was adjusted and the current time. The nitrogen oxide content of exhaust gas is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalyst converter.

[0161] Specifically, the timing starts after each adjustment of the target value of the air coefficient and continues until the next adjustment of the target value of the air coefficient stops and the timing restarts. The current time can be any time within this time period. By obtaining the nitrogen oxide content of multiple exhaust gases collected between the time of the last adjustment of the target value of the air coefficient and the current time, the first set of nitrogen oxide content of exhaust gases can be obtained. The nitrogen oxide content of exhaust gases in the first set of nitrogen oxide content of exhaust gases corresponds one-to-one with the first collection time.

[0162] Step S202: Based on the above set of first exhaust gas nitrogen oxide content, multiple first exhaust gas nitrogen oxide content change rates are calculated. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times.

[0163] Specifically, for example, if two adjacent first sampling times are t1 and t2, the corresponding nitrogen oxide content in the exhaust gas is n1. NOx and n2 NOx The rate of change of nitrogen oxide content in the first waste gas corresponding to the nitrogen oxide content is |n2 NOx - n1 NOx | / (t2- t1), of course, the change rate of the first exhaust gas nitrogen oxide content corresponding to the first exhaust gas nitrogen oxide content is 0.

[0164] Step S203: Delete the nitrogen oxide contents in the first set of nitrogen oxide contents in the first exhaust gas where the rate of change of nitrogen oxide contents in the first exhaust gas is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain the first set of nitrogen oxide contents in ...

[0165] Specifically, by deleting the nitrogen oxide content of the first exhaust gas from the set of nitrogen oxide content where the rate of change of the first exhaust gas nitrogen oxide content is greater than the first rate of change threshold and less than the second rate of change threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, and the accurate first nitrogen oxide ratio emission can be calculated.

[0166] Step S204: If the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, reduce the target value of the air coefficient.

[0167] Specifically, if the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, it indicates that the emission is not up to standard. The target value of the air coefficient lambda is then reduced to decrease the NOx emission ratio.

[0168] This invention provides a vehicle, which includes an engine system, one or more processors, a memory, and one or more programs. The engine system includes an engine and a three-way catalytic converter, the three-way catalytic converter being used to treat the exhaust gases of the engine. The one or more programs are stored in the memory and configured to be executed by the one or more processors. The one or more programs include the following steps:

[0169] Step S201: Obtain the nitrogen oxide content of exhaust gas at multiple first collection times within the first current timing period to obtain the first set of nitrogen oxide content of exhaust gas. The first current timing period is the time period between the last time the target value of the air coefficient was adjusted and the current time. The nitrogen oxide content of exhaust gas is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalyst converter.

[0170] Specifically, the timing starts after each adjustment of the target value of the air coefficient and continues until the next adjustment of the target value of the air coefficient stops and the timing restarts. The current time can be any time within this time period. By obtaining the nitrogen oxide content of multiple exhaust gases collected between the time of the last adjustment of the target value of the air coefficient and the current time, the first set of nitrogen oxide content of exhaust gases can be obtained. The nitrogen oxide content of exhaust gases in the first set of nitrogen oxide content of exhaust gases corresponds one-to-one with the first collection time.

[0171] Step S202: Based on the above set of first exhaust gas nitrogen oxide content, multiple first exhaust gas nitrogen oxide content change rates are calculated. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times.

[0172] Specifically, for example, if two adjacent first sampling times are t1 and t2, the corresponding nitrogen oxide content in the exhaust gas is n1. NOx and n2 NOx The rate of change of nitrogen oxide content in the first waste gas corresponding to the nitrogen oxide content is |n2 NOx - n1 NOx | / (t2- t1), of course, the change rate of the first exhaust gas nitrogen oxide content corresponding to the first exhaust gas nitrogen oxide content is 0.

[0173] Step S203: Delete the nitrogen oxide contents in the first set of nitrogen oxide contents in the first exhaust gas where the rate of change of nitrogen oxide contents in the first exhaust gas is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain the first set of nitrogen oxide contents in ...

[0174] Specifically, by deleting the nitrogen oxide content of the first exhaust gas from the set of nitrogen oxide content where the rate of change of the first exhaust gas nitrogen oxide content is greater than the first rate of change threshold and less than the second rate of change threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, and the accurate first nitrogen oxide ratio emission can be calculated.

[0175] Step S204: If the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, reduce the target value of the air coefficient.

[0176] Specifically, if the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, it indicates that the emission is not up to standard. The target value of the air coefficient lambda is then reduced to decrease the NOx emission ratio.

[0177] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0178] Step S201: Obtain the nitrogen oxide content of exhaust gas at multiple first collection times within the first current timing period to obtain the first set of nitrogen oxide content of exhaust gas. The first current timing period is the time period between the last time the target value of the air coefficient was adjusted and the current time. The nitrogen oxide content of exhaust gas is the nitrogen oxide content of the exhaust gas after treatment by the three-way catalyst converter.

[0179] Specifically, the timing starts after each adjustment of the target value of the air coefficient and continues until the next adjustment of the target value of the air coefficient stops and the timing restarts. The current time can be any time within this time period. By obtaining the nitrogen oxide content of multiple exhaust gases collected between the time of the last adjustment of the target value of the air coefficient and the current time, the first set of nitrogen oxide content of exhaust gases can be obtained. The nitrogen oxide content of exhaust gases in the first set of nitrogen oxide content of exhaust gases corresponds one-to-one with the first collection time.

[0180] Step S202: Based on the above set of first exhaust gas nitrogen oxide content, multiple first exhaust gas nitrogen oxide content change rates are calculated. The first exhaust gas nitrogen oxide content change rate is the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide content at two adjacent first collection times to the time difference between the two adjacent first collection times.

[0181] Specifically, for example, if two adjacent first sampling times are t1 and t2, the corresponding nitrogen oxide content in the exhaust gas is n1. NOx and n2 NOx The rate of change of nitrogen oxide content in the first waste gas corresponding to the nitrogen oxide content is |n2 NOx - n1 NOx | / (t2- t1), of course, the change rate of the first exhaust gas nitrogen oxide content corresponding to the first exhaust gas nitrogen oxide content is 0.

[0182] Step S203: Delete the nitrogen oxide contents in the first set of nitrogen oxide contents in the first exhaust gas where the rate of change of nitrogen oxide contents in the first exhaust gas is greater than the first rate of change threshold and less than the second rate of change threshold, to obtain the first set of nitrogen oxide contents in ...

[0183] Specifically, by deleting the nitrogen oxide content of the first exhaust gas from the set of nitrogen oxide content where the rate of change of the first exhaust gas nitrogen oxide content is greater than the first rate of change threshold and less than the second rate of change threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, and the accurate first nitrogen oxide ratio emission can be calculated.

[0184] Step S204: If the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, reduce the target value of the air coefficient.

[0185] Specifically, if the first nitrogen oxide emission ratio is greater than the first emission ratio threshold, it indicates that the emission is not up to standard. The target value of the air coefficient lambda is then reduced to decrease the NOx emission ratio.

[0186] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0187] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0188] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0189] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0190] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0191] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0192] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0193] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0194] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0195] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0196] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0197] 1) In the engine air coefficient control method of this application, experimental testing of the engine exhaust gas after treatment by the three-way catalytic converter revealed that the peak change rate of nitrogen oxide content was greater than that of ammonia content, and the peak change rate of ammonia content was greater than that of steady-state change rate of nitrogen oxide content. By deleting exhaust gas nitrogen oxide content from the first exhaust gas nitrogen oxide content set whose first exhaust gas nitrogen oxide content change rate was greater than the first change rate threshold and less than the second change rate threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, improving the accuracy of the first nitrogen oxide ratio emission. Thus, when the first nitrogen oxide ratio emission is higher than the first ratio emission threshold, the target value of the air coefficient lambda can be adjusted for closed-loop control to ensure emission compliance. This solves the problem of non-compliance of emission standards caused by inaccurate nitrogen oxide content detection in the existing engine air coefficient control method.

[0198] 2) In the engine air coefficient control device of this application, experimental detection of the engine exhaust gas after treatment by the three-way catalytic converter revealed that the peak change rate of nitrogen oxide content was greater than that of ammonia content, and the peak change rate of ammonia content was greater than that of steady-state change rate of nitrogen oxide content. By deleting exhaust gas nitrogen oxide content from the first exhaust gas nitrogen oxide content set whose first exhaust gas nitrogen oxide content change rate was greater than the first change rate threshold and less than the second change rate threshold, the influence of ammonia content on nitrogen oxide content measurement can be eliminated, improving the accuracy of the first nitrogen oxide ratio emission. Thus, when the first nitrogen oxide ratio emission is higher than the first ratio emission threshold, the target value of the air coefficient lambda can be adjusted for closed-loop control to ensure emission compliance. This solves the problem of non-compliance of emission standards caused by inaccurate nitrogen oxide content detection in the existing engine air coefficient control method.

[0199] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control method of an air coefficient of an engine, characterized by, The control method is applied to an engine system comprising the engine and a three-way catalyst converter for treating exhaust gas of the engine, and comprises: obtaining exhaust gas nitrogen oxide contents at a plurality of first collection time points in a first current timing time period to obtain a first exhaust gas nitrogen oxide content set, the first current timing time period being a time period between a time point of last time adjustment of a target value of the air coefficient and a current time point, the exhaust gas nitrogen oxide content being a nitrogen oxide content of exhaust gas treated by the three-way catalyst converter; calculating a plurality of first exhaust gas nitrogen oxide content change rates from the first exhaust gas nitrogen oxide content set, the first exhaust gas nitrogen oxide content change rate being a ratio of an absolute value of a difference between the exhaust gas nitrogen oxide contents at two adjacent first collection time points to a time difference between the two adjacent first collection time points; deleting, from the first exhaust gas nitrogen oxide content set, the exhaust gas nitrogen oxide contents with the first exhaust gas nitrogen oxide content change rates greater than a first change rate threshold and less than a second change rate threshold to obtain a first exhaust gas nitrogen oxide content correction set, and performing integral operation on the exhaust gas nitrogen oxide contents of the first exhaust gas nitrogen oxide content correction set to obtain a first nitrogen oxide specific emission; in a case where the first nitrogen oxide specific emission is greater than a first specific emission threshold, reducing the target value of the air coefficient.

2. The method of claim 1, wherein, The method further comprises: obtaining exhaust gas nitrogen oxide contents at a plurality of second collection time points in a second current timing time period to obtain a second exhaust gas nitrogen oxide content set, the second current timing time period being a time period between last time issuance of a fault alarm and the current time point; calculating a plurality of second exhaust gas nitrogen oxide content change rates from the second exhaust gas nitrogen oxide content set, the second exhaust gas nitrogen oxide content change rate being a ratio of an absolute value of a difference between the exhaust gas nitrogen oxide contents at two adjacent second collection time points to a time difference between the two adjacent second collection time points; deleting, from the second exhaust gas nitrogen oxide content set, the exhaust gas nitrogen oxide contents with the second exhaust gas nitrogen oxide content change rates greater than the first change rate threshold and less than the second change rate threshold to obtain a second exhaust gas nitrogen oxide content correction set, and performing integral operation on the exhaust gas nitrogen oxide contents of the second exhaust gas nitrogen oxide content correction set to obtain a second nitrogen oxide specific emission; in a case where the second nitrogen oxide specific emission is greater than a second specific emission threshold, issuing a fault alarm, the second specific emission threshold being greater than the first specific emission threshold.

3. The method of claim 1, wherein, performing integral operation on the exhaust gas nitrogen oxide contents of the first exhaust gas nitrogen oxide content correction set to obtain a first nitrogen oxide specific emission comprises: obtaining the exhaust gas nitrogen oxide contents less than or equal to the first change rate threshold in the first exhaust gas nitrogen oxide content correction set to obtain a first steady-state low value set; obtaining the first exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content correction set greater than or equal to the second change rate threshold, to obtain a first peak set; calculating the product of the first exhaust gas nitrogen oxide content in the first steady-state low value set and the corresponding exhaust gas flow at the first collection time, to obtain a first mass flow set, the exhaust gas flow being the flow of the exhaust gas discharged by the engine; calculating the product of the first exhaust gas nitrogen oxide content in the first peak set and the corresponding exhaust gas flow at the first collection time, to obtain a second mass flow set; integrating the first exhaust gas nitrogen oxide content of the first mass flow set along the time dimension to obtain a first nitrogen oxide emission, integrating the first exhaust gas nitrogen oxide content of the second mass flow set along the time dimension to obtain a second nitrogen oxide emission, and calculating the sum of the first nitrogen oxide emission and the second nitrogen oxide emission to obtain a first total nitrogen oxide emission; integrating the engine power at multiple first collection times in the first current timing period along the time dimension to obtain a first engine output; calculating the ratio of the first total nitrogen oxide emission to the first engine output to obtain the first nitrogen oxide specific emission.

4. The method of claim 1, wherein, deleting the first exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content set whose change rate is greater than the first change rate threshold and less than the second change rate threshold, to obtain a first exhaust gas nitrogen oxide content correction set, including: obtaining the air coefficient corresponding to the first collection time of the first exhaust gas nitrogen oxide content set; obtaining the exhaust gas nitrogen oxide content corresponding to the air coefficient greater than 1 in the first exhaust gas nitrogen oxide content set, to obtain a first target exhaust gas nitrogen oxide content set; deleting the exhaust gas nitrogen oxide content of the first target exhaust gas nitrogen oxide content set in the first exhaust gas nitrogen oxide content set, to obtain a second target exhaust gas nitrogen oxide content set; deleting the exhaust gas nitrogen oxide content in the second target exhaust gas nitrogen oxide content set whose change rate is greater than the first change rate threshold and less than the second change rate threshold, to obtain a third target exhaust gas nitrogen oxide content set; composing the first target exhaust gas nitrogen oxide content set and the third target exhaust gas nitrogen oxide content set into the first exhaust gas nitrogen oxide content correction set.

5. The method of claim 1, wherein, Before deleting the first exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content set whose change rate is greater than the first change rate threshold and less than the second change rate threshold, to obtain a first exhaust gas nitrogen oxide content correction set, the method further comprises: obtaining the ammonia content of the exhaust gas treated by the three-way catalyst converter at multiple historical times; generating an ammonia content change curve according to multiple historical times and corresponding ammonia contents; determining a maximum rate of change of the ammonia content of all peak segments of the ammonia content change curve as the second change rate threshold, the second change rate threshold being greater than the maximum rate of change of the ammonia content; determining a minimum rate of change of the ammonia content of all the peak segments as the first change rate threshold.

6. The method of claim 1, wherein, The three-way catalyst converter comprises a front three-way catalyst converter and a rear three-way catalyst converter through which the exhaust gas passes in sequence, a first current timing time period is obtained, and a plurality of first collection time points are obtained, to obtain a first exhaust gas nitrogen oxide content set, comprising: obtaining an exhaust gas parameter of the exhaust gas, the exhaust gas parameter comprising an exhaust gas temperature, an exhaust gas flow, an exhaust gas oxygen content and the exhaust gas nitrogen oxide content, the exhaust gas flow being the flow of the exhaust gas discharged by the engine, the exhaust gas temperature being the temperature of the exhaust gas after being processed by the front three-way catalyst converter, and the exhaust gas oxygen content being the oxygen content of the exhaust gas before being processed by the front three-way catalyst converter; in the case that the exhaust gas parameters are all within the corresponding predetermined ranges, activating the closed-loop control function of the air coefficient and recording the activation time; obtaining the exhaust gas nitrogen oxide content at a plurality of first collection time points in the first current timing time period, and deleting the exhaust gas nitrogen oxide content corresponding to the first collection time points before the activation time, to obtain the first exhaust gas nitrogen oxide content set.

7. The method according to any one of claims 1 to 6, characterized in that, The engine system further comprises a nitrogen oxide sensor for detecting the exhaust gas nitrogen oxide content, and before obtaining the exhaust gas nitrogen oxide content at a plurality of first collection time points in the first current timing time period to obtain the first exhaust gas nitrogen oxide content set, the method further comprises: obtaining the methane content of the exhaust gas; determining a corresponding correction coefficient according to the interval in which the methane content is located, the correction coefficient corresponding to the interval of the methane content in a one-to-one manner; correcting the nitrogen oxide sensor by using the correction coefficient, so that the exhaust gas nitrogen oxide content output by the nitrogen oxide sensor is the product of the original detection value and the correction coefficient.

8. A device for controlling the aerodynamic coefficient of an engine, characterized in that, The control device is applied to an engine system, the engine system comprising an engine and a three-way catalyst converter for processing the exhaust gas of the engine, and the control device comprising: a first obtaining unit for obtaining the exhaust gas nitrogen oxide content at a plurality of first collection time points in a first current timing time period to obtain a first exhaust gas nitrogen oxide content set, the first current timing time period being the time period between the time of last adjusting the target value of the air coefficient and the current time, and the exhaust gas nitrogen oxide content being the nitrogen oxide content of the exhaust gas after being processed by the three-way catalyst converter; a first calculating unit for calculating a plurality of first exhaust gas nitrogen oxide content change rates according to the first exhaust gas nitrogen oxide content set, the first exhaust gas nitrogen oxide content change rate being the ratio of the absolute value of the difference between the exhaust gas nitrogen oxide contents of two adjacent first collection time points to the time difference between the two adjacent first collection time points; The second calculation unit is configured to delete the exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content set, which has a first exhaust gas nitrogen oxide content rate greater than a first rate threshold and less than a second rate threshold, to obtain a first exhaust gas nitrogen oxide content correction set, and to perform an integral operation on the exhaust gas nitrogen oxide content in the first exhaust gas nitrogen oxide content correction set to obtain a first nitrogen oxide specific emission. The adjusting unit is configured to reduce the target value of the air coefficient when the first nitrogen oxide specific emission is greater than a first specific emission threshold.

9. A computer program product comprising a computer program, characterized in that, The computer program, when executed by a processor, implements the method of any one of claims 1 to 7.

10. A vehicle characterized by comprising: The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of any one of claims 1 to 7. The computer program, when executed by a processor, implements the method of

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