Emission Window Correction Method, Exhaust Gas Treatment System, Controller, and Storage Medium

Abstract

The present application provides a method for correcting an emission window, an exhaust gas treatment system, a controller, and a storage medium. The method includes: obtaining the actual engine speed, the actual engine torque, the engine emission flow rate, and the oxygen content in the engine pollutants under the current working condition; determining the specific emission target value of the engine according to the actual engine speed and the actual engine torque; determining the average specific emission value of the engine according to the actual engine speed, the actual engine torque, and the engine emission flow rate; determining the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correcting the lambda to be corrected by using the lambda correction value. The lambda emission window of the three-way catalytic converter is adaptively corrected by using the average specific emission value and the specific emission target value, so that the lambda emission window remains at the optimal position during the aging process of the three-way catalytic converter.

Description

Technical Field

[0001] The present application relates to the field of engines, and in particular, to a method for correcting an emission window, an exhaust gas treatment system, a controller, and a computer-readable storage medium. Background Art

[0002] Currently, natural gas engines generally use a three-way catalytic converter to treat the generated pollutants. The three-way catalytic converter can convert CO, HC, and NOx into CO2, H2O, and N2 through catalytic oxidation and reduction reactions. However, during the long-term operation of a natural gas engine, due to the three-way catalytic converter being in a high-temperature and rich water vapor environment for a long time, hydrothermal aging will gradually occur, resulting in a change in the optimal working lambda window value of the three-way catalytic converter, making the currently adopted fixed lambda window unable to achieve the best efficiency after the three-way catalytic converter ages. Summary of the Invention

[0003] The main object of the present application is to provide a method for correcting an emission window, an exhaust gas treatment system, a controller, and a computer-readable storage medium, so as to at least solve the problem in the prior art that the lambda window value in an engine cannot be adjusted and the best efficiency cannot be achieved after the three-way catalytic converter ages.

[0004] To achieve the above object, according to one aspect of the present application, a method for correcting an emission window is provided, including: obtaining the actual speed of the engine, the actual torque of the engine, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current working condition, where the emission flow rate is the emission flow rate of the pollutants after being treated by the three-way catalytic converter, and the oxygen content is the oxygen content in the pollutants after being treated by the three-way catalytic converter; determining a specific emission target value of the engine according to the actual speed and the actual torque of the engine, where the specific emission target value is the mass of the pollutants emitted per unit time when the engine outputs a unit of output work; determining an average specific emission value of the engine according to the actual speed, the actual torque, and the emission flow rate of the engine, where the average specific emission value is the average mass of the pollutants actually emitted by the engine when outputting the unit of output work during a predetermined time period; determining a lambda correction value according to the specific emission target value, the average specific emission value, and a direction control factor, and adaptively correcting the lambda to be corrected by using the lambda correction value, where the direction control factor is determined according to the oxygen content, the direction control factor is a factor for controlling the correction direction of the lambda to be corrected, and the lambda to be corrected is the lambda emission window value of the current three-way catalytic converter.

[0005] Optionally, determining the specific emission target value of the engine according to the actual rotational speed and the actual torque of the engine includes: determining the current actual power according to the actual rotational speed and the actual torque of the engine; determining the accumulated work within a predetermined time period and the duration of the predetermined time period according to the current actual power, where the accumulated work is obtained by integrating multiple current actual powers within the predetermined time period; determining the average rotational speed and the average intake charge according to the accumulated work and the duration of the predetermined time period, where the average rotational speed is the average rotational speed of the engine within the predetermined time period, and the average intake charge is the average intake charge of the engine within the predetermined time period; determining the specific emission target value according to the average rotational speed and the average intake charge.

[0006] Optionally, determining the average specific emission value of the engine according to the actual rotational speed, the actual torque, and the emission flow rate of the engine includes: determining the accumulated work within the predetermined time period according to the current actual power, where the accumulated work is obtained by integrating multiple current actual powers within the predetermined time period, and the current actual power is determined according to the actual rotational speed and the actual torque of the engine; integrating the emission flow rate within the predetermined time period to obtain the emission amount; determining the average specific emission value according to the emission amount and the accumulated work, where the average specific emission value is the ratio of the emission amount to the accumulated work.

[0007] Optionally, the method further includes: when the oxygen content is less than or equal to a preset content, the direction control factor is a first type of direction factor, and the first type of direction factor is a negative value; when the oxygen content is greater than the preset content, the direction control factor is a second type of direction factor, and the second type of direction factor is a positive value.

[0008] Optionally, determining the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor includes: determining a correction deviation value according to the specific emission target value and the average specific emission value, where the correction deviation value is the difference between the specific emission target value and the average specific emission value; performing normalization processing on the correction deviation value to obtain a normalization result; determining the lambda correction value according to the normalization result and the direction control factor, where the lambda correction value is obtained through PID control of the product of the normalization result and the direction control factor.

[0009] Optionally, before determining the lambda correction value according to the normalization result and the direction control factor, the method further includes: determining the average engine speed and the average intake charge of the engine according to the actual engine speed and the actual engine torque of the engine; obtaining an amplitude correction factor, where the amplitude correction factor is the product of a plurality of correlation coefficients, and the correlation coefficients are at least one of the following: the aging correction coefficient of the three-way catalytic converter, the correction coefficient of the post-treatment temperature, and the concentration correction coefficient of nitrogen oxides downstream of the three-way catalytic converter; determining the proportional regulation coefficient of the PID control according to the average engine speed and the average intake charge, where the proportional regulation coefficient is used to quickly adjust the error generated in the PID control; determining the integral regulation coefficient of the PID control according to the average engine speed, the average intake charge, and the amplitude correction factor, where the integral regulation coefficient is used to adjust the steady-state time in the PID control.

[0010] Optionally, after determining the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correcting the lambda to be corrected using the lambda correction value, the method further includes: adaptively correcting the lambda to be corrected according to the lambda correction value to obtain a corrected lambda value; applying the corrected lambda value in the next working condition, where the actual engine speed in the next working condition is the same as the actual engine speed in the current working condition and the actual engine torque in the next working condition is the same as the actual engine torque in the current working condition; obtaining the pollutant emission value in the same working condition after applying the corrected lambda value; and storing the corrected lambda value in a data table when the pollutant emission value meets a preset condition.

[0011] According to another aspect of the present application, there is provided an exhaust gas treatment system, including: a three-way catalytic converter; a nitrogen oxygen sensor installed downstream of the three-way catalytic converter for obtaining the oxygen content in the pollutants of the engine; and a controller communicatively connected to the three-way catalytic converter and the nitrogen oxygen sensor for executing any one of the emission window correction methods.

[0012] According to another aspect of the present application, a controller is provided, including: an acquisition unit configured to acquire the actual rotational speed of the engine, the actual torque of the engine, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current operating condition, where the emission flow rate is the emission flow rate of the pollutants after being treated by the three-way catalytic converter, and the oxygen content is the oxygen content in the pollutants after being treated by the three-way catalytic converter; a first determination unit configured to determine the specific emission target value of the engine according to the actual rotational speed and the actual torque of the engine, where the specific emission target value is the mass of the pollutants emitted per unit time when the engine outputs a unit of output work; a second determination unit configured to determine the average specific emission value of the engine according to the actual rotational speed, the actual torque, and the emission flow rate of the engine, where the average specific emission value is the average mass of the pollutants actually emitted by the engine within a predetermined period when the engine outputs the unit of output work; a correction unit configured to determine a lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correct the lambda to be corrected by using the lambda correction value, where the direction control factor is determined according to the oxygen content, the direction control factor is a factor for controlling the correction direction of the lambda to be corrected, and the lambda to be corrected is the lambda emission window value of the current three-way catalytic converter.

[0013] According to another aspect of the present application, a computer-readable storage medium is provided, where the computer-readable storage medium includes a stored program, and when the program runs, it controls the device where the computer-readable storage medium is located to execute any one of the above emission window correction methods.

[0014] Applying the technical solution of the present application, for the above emission window correction method, first, the actual rotational speed of the engine, the actual torque of the engine, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current operating condition are acquired; the specific emission target value of the engine is determined according to the actual rotational speed and the actual torque of the engine; the average specific emission value of the engine is determined according to the actual rotational speed, the actual torque, and the emission flow rate of the engine; the lambda correction value is determined according to the specific emission target value, the average specific emission value, and the direction control factor, and the lambda to be corrected is adaptively corrected by using the lambda correction value. The lambda emission window of the three-way catalytic converter is adaptively corrected by using the average specific emission value and the specific emission target value, so that the lambda emission window remains at the optimal position during the aging process of the three-way catalytic converter, solving the problem in the prior art that the lambda window value in the engine cannot be adjusted and the optimal efficiency cannot be achieved after the three-way catalytic converter ages, and avoiding the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0016] Figure 1 A flowchart showing a method for correcting an emission window provided according to an embodiment of this application is shown;

[0017] Figure 2 A flowchart showing another method for correcting an emission window provided according to an embodiment of this application is shown;

[0018] Figure 3 A flowchart showing still another method for correcting an emission window provided according to an embodiment of this application is shown;

[0019] Figure 4 A flowchart showing yet another method for correcting an emission window provided according to an embodiment of this application is shown;

[0020] Figure 5 A schematic diagram of an exhaust gas treatment system provided according to an embodiment of this application is shown;

[0021] Figure 6 A block diagram of a controller structure provided according to an embodiment of this application is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The following will describe this application in detail with reference to the drawings and in combination with the embodiments.

[0023] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0024] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of this application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] For the sake of convenience of description, some nouns or terms related to the embodiments of this application are described below:

[0026] Three-way catalytic converter (TWC): The most important off-vehicle purification device installed in the vehicle exhaust system, which can convert harmful gases such as carbon monoxide, nitrogen oxides and unburned hydrocarbons in vehicle exhaust into harmless carbon dioxide, water and nitrogen through oxidation and reduction reactions.

[0027] Front oxygen sensor: A sensor installed on the exhaust pipe in front of the three-way catalytic converter, used to detect the oxygen concentration in the exhaust gas.

[0028] Rear oxygen sensor: A sensor installed on the exhaust pipe behind the three-way catalytic converter, used to detect the oxygen concentration in the exhaust gas.

[0029] Lambda: The ratio of the actual amount of air required to burn a certain amount of fuel to the theoretical amount of air.

[0030] As introduced in the background art, currently natural gas engines generally use three-way catalytic converters to treat the generated exhaust gas. The three-way catalytic converter can convert CO, HC and NOx into CO2, H2O and N2 through catalytic oxidation and reduction reactions; however, during the long-term operation of natural gas engines, due to the three-way catalytic converter being in a high-temperature and rich water vapor environment for a long time, the situation of hydrothermal aging will gradually occur, resulting in a change in the optimal working lambda window value of the three-way catalytic converter, making the currently adopted fixed lambda window unable to achieve the best efficiency after the three-way catalytic converter ages. To solve the problem that the lambda window value in the existing technology engine cannot be adjusted and the best efficiency cannot be achieved after the three-way catalytic converter ages, the embodiments of this application provide an emission window correction method, an exhaust gas treatment system, a controller and a computer-readable storage medium.

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0032] In this embodiment, a method for correcting an emission window running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0033] In the prior art, an emission window correction method based on a catalytic converter aging factor is usually used. According to the change of the readings of the front and rear oxygen sensors, under appropriate working conditions, the oxygen flow is integrated to obtain the current oxygen storage capacity of the TWC, and then it is compared with the oxygen storage capacities of the TWC fresh part, the critical aging part and the critical aging factor, and the aging factor of the current TWC is interpolated and calculated. Finally, this aging factor is used to correct the emission window.

[0034] Due to the oxygen storage characteristic of the TWC, oxygen is stored in the lean mixture stage, and when the rich mixture stage occurs, the stored oxygen reacts with the exhaust gas. As the catalytic converter ages, its oxygen storage capacity will decrease. Therefore, the conversion efficiency of the catalytic converter can be indirectly reflected by the oxygen storage capacity. The emission window correction method based on the catalytic converter aging factor adopted in the prior art is to indirectly reflect the aging degree of the TWC according to the size of the oxygen storage capacity, and then correct the emission window according to the aging factor. Among them, the calculation of the oxygen storage amount is to determine the start and end of the integration of the oxygen flow according to the change of the voltage value of the switching oxygen sensor. The oxygen storage amount actually calculated in this way is not accurate and is easily affected by factors such as working conditions and the external environment. Moreover, the working conditions for its calculation are relatively special and the final release conditions are relatively complex, resulting in poor timeliness of the aging factor calculated in this way. In addition, the aging degree of the TWC has a greater impact on the reduction ability of NOx in the emissions. The size of the oxygen storage amount and the reduction ability of the TWC for NOx are not an absolute linear relationship. Therefore, the aging factor calculated by this method cannot accurately judge the conversion efficiency of the current TWC for NOx and cannot effectively correct the emission window, thus affecting the control of emissions such as NOx throughout the life cycle of the TWC.

[0035] Among them, before starting the closed-loop correction, it is generally necessary to judge the working conditions and release conditions, that is, to judge whether the current state of the engine can perform closed-loop correction. Specifically, the engine needs to maintain a steady state and have no faults, and the following conditions need to be met:

[0036] 1. Steady state conditions and working condition range limitations, that is, parameters such as the engine speed and intake impulse are within a certain range;

[0037] 2. Ambient temperature and ambient pressure range limits. Generally, the ambient temperature is -40°C to 50°C, and the ambient pressure range limit is generally 1000 Pa;

[0038] 3. The downstream NOx sensor (nitrogen oxide sensor) is ready, that is, the downstream NOx sensor can be used normally;

[0039] 4. The engine temperature is within a certain range, generally 84°C to 87°C;

[0040] 5. The after-treatment temperature is within a certain range, that is, the exhaust gas temperature is within a certain range;

[0041] 6. The upstream lambda is within the limit range;

[0042] 7. The filtered downstream NOx is within a certain range;

[0043] 8. The lambda closed-loop is turned on;

[0044] 9. No fault is triggered.

[0045] When the conditions are met, the calculation of the release power window is allowed and the timer is triggered. Figure 1 is a flowchart of the emission window correction method according to an embodiment of the present application. As Figure 1 shown, the method includes the following steps:

[0046] Step S201, obtain the true speed of the engine, the true torque of the engine, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current working condition. The emission flow rate is the emission flow rate of the pollutants after being treated by the three-way catalytic converter, and the oxygen content is the oxygen content in the pollutants after being treated by the three-way catalytic converter;

[0047] Step S202, determine the specific emission target value of the engine according to the true speed and the true torque of the engine. The specific emission target value is the mass of the pollutants emitted per unit time when the engine outputs unit output work;

[0048] Among them, as Figure 2 shown, the specific implementation steps of step S202 are as follows:

[0049] Step S2021, determine the current actual power according to the true speed and the true torque of the engine. Among them, the current actual power can be calculated according to formula 1 to formula 4;

[0050] P = F × V (formula 1)

[0051]

[0052] P = T×ω (Formula 3)

[0053] P = T×2πn (Formula 4)

[0054] Among them, P is the current actual power, F is the torque, V is the linear velocity in the direction of F, T is the true torque of the above engine, ω is the angular velocity, R is the acting radius, and n is the true rotational speed of the above engine.

[0055] Since the unit of the true rotational speed of the above engine in Formulas 1 to 4 is (revolutions per minute), the unit of the current actual power is (w), 60 in Formula 5 is the unit conversion between minutes and seconds, 1000 in Formula 5 is the unit conversion between watts and kilowatts, and 9550 in Formula 6 is obtained by substituting π in Formula 5 with 3.14. The specific calculation process is shown in the following Formulas 5 - 6:

[0056]

[0057]

[0058] At this time, the unit of power in Formula 6 is (kw), and the unit of the true rotational speed of the engine is (revolutions per second).

[0059] Step S2022: Determine the cumulative work within a predetermined time period and the duration of the above - mentioned predetermined time period according to the above - mentioned current actual power. The above - mentioned cumulative work is obtained by integrating multiple above - mentioned current actual powers within the above - mentioned predetermined time period. Among them, the cumulative work within the above - mentioned predetermined time is a window;

[0060] Step S2023: Determine the average rotational speed and the average intake charge according to the above - mentioned cumulative work and the duration of the above - mentioned predetermined time period. The above - mentioned average rotational speed is the average rotational speed of the above - mentioned engine within the above - mentioned predetermined time period, and the above - mentioned average intake charge is the average intake charge of the above - mentioned engine within the above - mentioned predetermined time period. Among them, the average rotational speed is the integrated rotational speed divided by the predetermined time; the average intake charge is the integrated intake charge divided by the predetermined time;

[0061] Step S2024: Determine the above - mentioned specific emission target value according to the above - mentioned average rotational speed and the above - mentioned average intake charge. Generally, it is obtained by looking up the MAP table.

[0062] Among them, under the cumulative work (or time) window, by comprehensively analyzing the operating condition information and the rich - lean situation within the window, the closed - loop control of NOx specific emission can be achieved.

[0063] Step S203: Determine the average specific emission value of the engine based on the actual rotational speed, actual torque, and emission flow rate of the engine. The average specific emission value is the average mass of pollutants actually emitted by the engine during a predetermined period when the engine outputs a unit of output work.

[0064] Among them, as Figure 3 shown, the specific implementation steps included in Step S203 are as follows:

[0065] Step S2031: Determine the cumulative work during the predetermined period based on the current actual power. The cumulative work is obtained by integrating multiple current actual powers during the predetermined period. Among them, the current actual power is determined based on the actual rotational speed and actual torque of the engine. The specific determination method is as shown in Step S2021.

[0066] Step S2032: Integrate the emission flow rate during the predetermined period to obtain the emission amount.

[0067] Step S2033: Determine the average specific emission value based on the emission amount and the cumulative work. The average specific emission value is the ratio of the emission amount to the cumulative work.

[0068] By calculating the average specific emission value under a fixed window, the lambda value is adjusted using the deviation condition between the actual average specific emission value and the theoretical target specific emission value to achieve closed-loop control of NOx.

[0069] Step S204: Determine the lambda correction value based on the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correct the lambda to be corrected using the lambda correction value. Among them, the direction control factor is determined based on the oxygen content. The direction control factor is a factor for controlling the correction direction of the lambda to be corrected. The lambda to be corrected is the current lambda emission window value of the three-way catalytic converter.

[0070] To control the correction direction of the lambda to be corrected, the method further includes: when the oxygen content is less than or equal to the preset content, the direction control factor is a first-type direction factor, and the first-type direction factor is a negative value; when the oxygen content is greater than the preset content, the direction control factor is a second-type direction factor, and the second-type direction factor is a positive value.

[0071] Specifically, when the oxygen content is less than or equal to the preset content, it is considered that the current emissions are mainly NH3. When the oxygen content is greater than the preset content, it is considered that the current emissions are mainly NOx.

[0072] Among them, determining the lambda correction value according to the above specific emission target value, the above average specific emission value and the direction control factor includes: determining a correction deviation value according to the above specific emission target value and the above average specific emission value, where the correction deviation value is the difference between the above specific emission target value and the above average specific emission value; performing normalization processing on the above correction deviation value to obtain a normalization result; determining the above lambda correction value according to the above normalization result and the above direction control factor, where the above lambda correction value is obtained through PID control of the product of the above normalization result and the above direction control factor.

[0073] Specifically, normalization is a dimensionless processing method that makes the absolute value of the physical system value become a relationship of a certain relative value. For example, for a system with a sampling frequency of 500 hz, the normalized frequency of 400 hz is 400 / 500 = 0.8, and the normalized frequency range is 0 - 1; PID control is proportional-integral-derivative control, that is, a control deviation is formed according to the given value and the actual output value, and the deviation is linearly combined by proportion, integral and derivative to form a control quantity to control the controlled object.

[0074] Before determining the above lambda correction value according to the above normalization result and the above direction control factor, the above method further includes: determining the average speed and the average intake charge of the above engine according to the actual speed and the actual torque of the above engine; obtaining an amplitude correction factor, where the amplitude correction factor is the product of multiple correlation coefficients, and the correlation coefficients are at least one of the following: the aging correction coefficient of the above three-way catalytic converter, the correction coefficient of the post-treatment temperature, the concentration correction coefficient of nitrogen oxides downstream of the above three-way catalytic converter; determining the proportional adjustment coefficient of the above PID control according to the above average speed and the above average intake charge, where the proportional adjustment coefficient is used to quickly adjust the error generated in the above PID control; determining the integral adjustment coefficient of the above PID control according to the above average speed, the above average intake charge and the above amplitude correction factor, where the integral adjustment coefficient is used to adjust the steady-state time in the above PID control. Among them, the proportional adjustment coefficient is the Kp coefficient in the PID calculation, and generally is obtained by looking up the MAP according to the above average speed and the above average intake charge, and the integral adjustment coefficient is the Ki coefficient in the PID calculation, and generally is calculated by taking the above average speed and the above average intake charge as the basic MAP and then multiplying by the amplitude correction factor.

[0075] Generally, the above correlation coefficients are mainly composed of the following parts:

[0076] 1. The three-way catalytic converter aging coefficient is checked by CUR correction;

[0077] 2. Upstream lambda maximum change rate within the window checks CUR correction;

[0078] 3. Upstream lambda average value within the window checks CUR correction

[0079] 4. Post-treatment temperature (exhaust gas temperature behind the turbine, temperature upstream of the TWC) and its maximum change rate within the window checks MAP correction;

[0080] 5. Upstream lambda average change rate within the window checks CUR correction;

[0081] 6. Maximum change rate of rotational speed and intake air volume within the window checks MAP correction;

[0082] 7. Correction factor obtained from the average rotational speed and average intake air charge of the current window checks CUR correction;

[0083] 8. Downstream NOx concentration checks CUR correction;

[0084] The values of the above coefficients are all between 0 and 1. Among them, the amplitude correction factor can also be used to correct the amplitude of the lambda to be corrected.

[0085] After determining the lambda correction value according to the above specific emission target value, the above average specific emission value and the direction control factor, and adaptively correcting the lambda to be corrected using the above lambda correction value, the above method further includes: adaptively correcting the lambda to be corrected according to the above lambda correction value to obtain the corrected lambda value; applying the above corrected lambda value to the next working condition, where the true rotational speed of the engine in the above next working condition is the same as the true rotational speed of the engine in the current working condition and the true torque of the engine in the above next working condition is the same as the true torque of the engine in the current working condition; obtaining the pollutant emission value under the same working condition after applying the above corrected lambda value; and storing the above corrected lambda value in the data table when the above pollutant emission value meets the preset conditions. Among them, the above data table can be a self-learning MAP table, and the above preset condition is that the weight of the pollutants emitted by the engine is lower than the limit. The lambda window correction amount needs to be verified through the same working condition window before being written into the full working condition self-learning MAP to ensure the effectiveness of the correction. It can verify whether the lambda correction amount output by the current window is effective. After confirming the reduction of emissions under the same working condition, it is written into the full working condition MAP to participate in the adjustment of lambda to ensure the effectiveness of the correction.

[0086] Specifically, according to different operating conditions of the engine, the above method can be used to calculate different corrected lambda values and confirm them, that is, apply the corrected lambda value to the next operating condition identical to the current one, and obtain the pollutant emission value under this condition. After successful confirmation, multiple corrected lambda values can be written into the self-learning MAP table, so that the multiple corrected lambda values output by this MAP are valid for the entire operating condition. During this process, the aging adaptive correction of the emission window is realized.

[0087] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the emission window correction method of the present application will be described in detail below in conjunction with specific embodiments.

[0088] This embodiment relates to a specific emission window correction method. As Figure 4 shown, first, when the engine meets the release condition, start the adaptive enabling (i.e., start the adaptive correction), then calculate the cumulative work and emissions within a predetermined time period, and then determine the average specific emission value and the target specific emission value based on the cumulative work, the duration of the predetermined time period, and the emissions. Then calculate the difference between the above specific emission target value and the above average specific emission value as the correction deviation value. At the same time, determine the direction control factor according to the oxygen concentration measured by the nitrogen oxide sensor, obtain the amplitude correction factor based on multiple relevant parameters, adaptively correct and confirm the lambda to be corrected under multiple operating conditions according to the direction control factor, the amplitude correction factor, and the correction deviation value. Finally, write the confirmed multiple corrected lambda values into the self-learning MAP table, so that the multiple corrected lambda values output by this MAP are valid for the entire operating condition. Re-entering the same operating condition can directly use the correction value in the self-learning MAP for correction, improving the real-time performance and reducing the emissions. During the above correction process, the aging adaptive correction of the emission window is realized.

[0089] The above-mentioned emission window correction method of the present application first obtains the actual engine speed, actual engine torque, engine emission flow rate, and oxygen content in the engine pollutants under the current working condition; determines the specific emission target value of the engine according to the actual engine speed and actual engine torque; determines the average specific emission value of the engine according to the actual engine speed, actual engine torque, and engine emission flow rate; determines the lambda correction value according to the specific emission target value, average specific emission value, and direction control factor, and adaptively corrects the lambda to be corrected using the lambda correction value. This method adaptively corrects the lambda emission window of the three-way catalytic converter using the average specific emission value and the specific emission target value, so that the lambda emission window remains at the optimal position during the aging process of the three-way catalytic converter, solves the problem in the prior art that the lambda window value in the engine cannot be adjusted and cannot reach the optimal efficiency after the three-way catalytic converter ages, and avoids the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions.

[0090] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0091] The embodiment of the present application also provides an exhaust gas treatment system, as Figure 5 shown, including: a three-way catalytic converter; a nitrogen oxide sensor installed downstream of the above three-way catalytic converter for obtaining the oxygen content in the engine pollutants; a controller communicatively connected to the above three-way catalytic converter and the above nitrogen oxide sensor for executing any one of the above-mentioned emission window correction methods.

[0092] By installing a NOx sensor (nitrogen oxide sensor) downstream of the TWC, calculating the specific emission value under a fixed window, and using the deviation condition between the actual specific emission and the theoretical specific emission to adjust lambda to achieve closed-loop control of NOx;

[0093] Among them, the above exhaust gas treatment system further includes a wide-range oxygen sensor installed upstream of the three-way catalytic converter. The oxygen concentration measured by the wide-range oxygen sensor generates an electric current, and then the corresponding lambda value is found through a data table.

[0094] The above exhaust gas treatment system of the present application includes: a three-way catalytic converter; a nitrogen oxide sensor installed downstream of the three-way catalytic converter for obtaining the oxygen content in the pollutants of the engine; and a controller communicatively connected to the three-way catalytic converter and the nitrogen oxide sensor for executing any one of the above emission window correction methods. This system adaptively corrects the lambda emission window of the three-way catalytic converter by using the average specific emission value and the specific emission target value, so that the lambda emission window remains in the optimal position during the aging process of the three-way catalytic converter, solves the problem in the prior art that the lambda window value in the engine cannot be adjusted and cannot reach the optimal efficiency after the three-way catalytic converter ages, and avoids the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions.

[0095] The embodiment of the present application also provides an emission window correction device. It should be noted that the emission window correction device of the embodiment of the present application can be used to execute the emission window correction method provided by the embodiment of the present application. The device is used to implement the above embodiments and preferred implementation manners, and those that have been described will not be repeated. As used hereinafter, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0096] The following introduces the emission window correction device provided by the embodiment of the present application.

[0097] Figure 6 is a schematic diagram of the controller according to the embodiment of the present application. As Figure 6As shown in the figure, the controller includes an acquisition unit 10, a first determination unit 20, a second determination unit 30, and a correction unit 40. The acquisition unit 10 is configured to acquire the true rotational speed of the engine, the true torque of the engine, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current operating conditions. The emission flow rate is the emission flow rate of the pollutants after being treated by the three-way catalyst, and the oxygen content is the oxygen content in the pollutants after being treated by the three-way catalyst. The first determination unit 20 is configured to determine the specific emission target value of the engine according to the true rotational speed and the true torque of the engine. The specific emission target value is the mass of the pollutants emitted per unit time when the engine outputs a unit of output work. The second determination unit 30 is configured to determine the average specific emission value of the engine according to the true rotational speed, the true torque, and the emission flow rate of the engine. The average specific emission value is the average mass of the pollutants actually emitted by the engine when the engine outputs the unit of output work during a predetermined period. The correction unit 40 is configured to determine a lambda correction value according to the specific emission target value, the average specific emission value, and a direction control factor, and adaptively correct the lambda to be corrected by using the lambda correction value. Among them, the direction control factor is determined according to the oxygen content, and the direction control factor is a factor for controlling the correction direction of the lambda to be corrected. The lambda to be corrected is the lambda emission window value of the current three-way catalyst.

[0098] Exemplarily, the first determination unit includes a first determination module, a second determination module, a third determination module, and a fourth determination module. The first determination module is configured to determine the current actual power according to the true rotational speed and the true torque of the engine. The second determination module is configured to determine the cumulative work during a predetermined period and the duration of the predetermined period according to the current actual power. The cumulative work is obtained by integrating a plurality of the current actual powers during the predetermined period. The third determination module is configured to determine the average rotational speed and the average intake charge according to the cumulative work and the duration of the predetermined period. The average rotational speed is the average rotational speed of the engine during the predetermined period, and the average intake charge is the average intake charge of the engine during the predetermined period. The fourth determination module is configured to determine the specific emission target value according to the average rotational speed and the average intake charge. Under the cumulative work (or time) window, by comprehensively analyzing the operating condition information and the rich-lean condition within the window, the closed-loop control of the NOx specific emission can be achieved.

[0099] In an alternative solution, the second determination unit includes a fifth determination module, a first integration module, and a sixth determination module. The fifth determination module is configured to determine the cumulative work within the above-mentioned predetermined time period according to the current actual power, where the cumulative work is obtained by integrating a plurality of the above-mentioned current actual powers within the above-mentioned predetermined time period, and wherein the above-mentioned current actual power is determined according to the true rotational speed and the true torque of the above-mentioned engine; the first integration module is configured to integrate the above-mentioned emission flow rate within the above-mentioned predetermined time period to obtain an emission amount; the sixth determination module is configured to determine the above-mentioned average specific emission value according to the above-mentioned emission amount and the above-mentioned cumulative work, and the above-mentioned average specific emission value is the ratio of the above-mentioned emission amount to the above-mentioned cumulative work. By calculating the average specific emission value under a fixed window, the lambda value is adjusted using the deviation condition between the actual average specific emission value and the theoretical target specific emission value to achieve closed-loop control of NOX.

[0100] As an alternative solution, when the oxygen content is less than or equal to a preset content, the above-mentioned direction control factor is a first type of direction factor, and the above-mentioned first type of direction factor is a negative value; when the oxygen content is greater than the above-mentioned preset content, the above-mentioned direction control factor is a second type of direction factor, and the above-mentioned second type of direction factor is a positive value. The correction direction of the lambda to be corrected can be controlled.

[0101] In this embodiment, the correction unit includes a first determination subunit, a processing subunit, and a second determination subunit. The first determination subunit is configured to determine a correction deviation value according to the above-mentioned specific emission target value and the above-mentioned average specific emission value, and the above-mentioned correction deviation value is the difference between the above-mentioned specific emission target value and the above-mentioned average specific emission value; the processing subunit is configured to perform normalization processing on the above-mentioned correction deviation value to obtain a normalization result; the second determination subunit is configured to determine the above-mentioned lambda correction value according to the above-mentioned normalization result and the above-mentioned direction control factor, where the above-mentioned lambda correction value is obtained by performing PID control on the product of the above-mentioned normalization result and the above-mentioned direction control factor. Using the actual average specific emission value and the theoretical target specific emission value, the lambda emission window correction amount can be output, that is, the lambda correction value is determined.

[0102] In an alternative solution, the above-mentioned controller further includes a third determination unit, a first acquisition subunit, a fourth determination unit, and a fifth determination unit. The third determination unit is configured to determine the average rotational speed and the average intake air charge of the engine according to the actual rotational speed and the actual torque of the engine. The first acquisition subunit is configured to acquire an amplitude correction factor, which is the product of a plurality of correlation coefficients, and the correlation coefficients are at least one of the following: the aging correction coefficient of the three-way catalyst, the correction coefficient of the after-treatment temperature, and the concentration correction coefficient of nitrogen oxides downstream of the three-way catalyst. The fourth determination unit is configured to determine the proportional regulation coefficient of the PID control according to the average rotational speed and the average intake air charge, and the proportional regulation coefficient is used to quickly adjust the error generated in the PID control. The fifth determination unit is configured to determine the integral regulation coefficient of the PID control according to the average rotational speed, the average intake air charge, and the amplitude correction factor, and the integral regulation coefficient is used to adjust the steady-state time in the PID control. Normalization processing can be performed more accurately.

[0103] In an alternative example, the above-mentioned controller further includes a correction subunit, an application unit, a second acquisition subunit, and a storage unit. The correction subunit is configured to adaptively correct the to-be-corrected lambda according to the lambda correction value to obtain a corrected lambda value. The application unit is configured to apply the corrected lambda value to the next working condition, where the actual rotational speed of the engine in the next working condition is the same as the actual rotational speed of the engine in the current working condition and the actual torque of the engine in the next working condition is the same as the actual torque of the engine in the current working condition. The second acquisition subunit is configured to acquire the pollutant emission value under the same working condition after applying the corrected lambda value. The storage unit is configured to store the corrected lambda value in a data table when the pollutant emission value meets a preset condition. It verifies whether the lambda correction amount output by the current window is effective. After confirming the emission reduction under the same working condition, it is written into the full working condition MAP to participate in the adjustment of lambda to ensure the effectiveness of the correction.

[0104] The above-mentioned controller of the present application includes an acquisition unit, a first determination unit, a second determination unit, and a correction unit. The acquisition unit is used to acquire the actual speed of the engine, the actual torque of the engine, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current working condition; the first determination unit is used to determine the specific emission target value of the engine according to the actual speed and the actual torque of the engine; the second determination unit is used to determine the average specific emission value of the engine according to the actual speed, the actual torque, and the emission flow rate of the engine; the correction unit is used to determine the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correct the lambda to be corrected by using the lambda correction value. This controller adaptively corrects the lambda emission window of the three-way catalytic converter by using the average specific emission value and the specific emission target value, so that the lambda emission window remains in the optimal position during the aging process of the three-way catalytic converter, solves the problem in the prior art that the lambda window value in the engine cannot be adjusted and cannot reach the optimal efficiency after the three-way catalytic converter ages, and avoids the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions.

[0105] The above-mentioned emission window correction device includes a processor and a memory. The above-mentioned acquisition unit, etc. are all stored in the memory as program units, and the corresponding functions are realized by the processor executing the above-mentioned program units stored in the memory. The above-mentioned modules are all located in the same processor; or, the above-mentioned each module is located in different processors in any combination form.

[0106] The processor includes a kernel, and the kernel retrieves the corresponding program unit from the memory. One or more kernels can be set, and by adjusting the kernel parameters, the problem in the prior art that the lambda window value in the engine cannot be adjusted and cannot reach the optimal efficiency after the three-way catalytic converter ages is solved.

[0107] The memory may include non-permanent memory in a computer-readable medium, forms such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM), and the memory includes at least one storage chip.

[0108] An embodiment of the present invention provides a computer-readable storage medium. The above-mentioned computer-readable storage medium includes a stored program, wherein when the above-mentioned program runs, it controls the device where the above-mentioned computer-readable storage medium is located to execute the above-mentioned emission window correction method.

[0109] Specifically, the emission window correction method includes:

[0110] Step S2021, determine the current actual power according to the actual speed and the actual torque of the above engine;

[0111] Specifically, before starting the closed-loop correction, it is generally also necessary to judge the working condition and release conditions, that is, to judge whether the current state of the engine can perform closed-loop correction. Specifically, the engine needs to maintain a steady state and have no faults;

[0112] Step S202, determine the specific emission target value of the above engine according to the actual speed and the actual torque of the above engine, and the specific emission target value is the mass of pollutants emitted per unit time when the above engine outputs unit output work;

[0113] Specifically, it can effectively correct the current lambda to be corrected;

[0114] Step S203, determine the average specific emission value of the above engine according to the actual speed, the actual torque and the emission flow of the above engine, and the average specific emission value is the average mass of pollutants actually emitted by the above engine within a predetermined time period when the above engine outputs the above unit output work;

[0115] Specifically, it can accurately calculate the average specific emission value of the engine under the current working condition;

[0116] Step S204, determine the lambda correction value according to the specific emission target value, the average specific emission value and the direction control factor, and adaptively correct the lambda to be corrected by using the above lambda correction value, wherein the above direction control factor is determined according to the above oxygen content, the above direction control factor is a factor for controlling the correction direction of the above lambda to be corrected, and the above lambda to be corrected is the lambda emission window value of the current three-way catalytic converter.

[0117] Specifically, the correction direction of the lambda to be corrected can be well controlled by the direction control factor.

[0118] Optionally, determining the specific emission target value of the engine according to the actual speed and the actual torque of the engine includes: determining the current actual power according to the actual speed and the actual torque of the engine; determining the cumulative work within a predetermined period and the duration of the predetermined period according to the current actual power, where the cumulative work is obtained by integrating a plurality of the current actual powers within the predetermined period; determining the average speed and the average intake charge according to the cumulative work and the duration of the predetermined period, where the average speed is the average speed of the engine within the predetermined period, and the average intake charge is the average intake charge of the engine within the predetermined period; determining the specific emission target value according to the average speed and the average intake charge.

[0119] Optionally, determining the average specific emission value of the engine according to the actual speed, the actual torque and the emission flow rate of the engine includes: determining the cumulative work within the predetermined period according to the current actual power, where the cumulative work is obtained by integrating a plurality of the current actual powers within the predetermined period, and the current actual power is determined according to the actual speed and the actual torque of the engine; integrating the emission flow rate within the predetermined period to obtain the emission amount; determining the average specific emission value according to the emission amount and the cumulative work, where the average specific emission value is the ratio of the emission amount to the cumulative work.

[0120] Optionally, the method further includes: when the oxygen content is less than or equal to a preset content, the direction control factor is a first type of direction factor, and the first type of direction factor is a negative value; when the oxygen content is greater than the preset content, the direction control factor is a second type of direction factor, and the second type of direction factor is a positive value.

[0121] Optionally, determining the lambda correction value according to the specific emission target value, the average specific emission value and the direction control factor includes: determining a correction deviation value according to the specific emission target value and the average specific emission value, where the correction deviation value is the difference between the specific emission target value and the average specific emission value; normalizing the correction deviation value to obtain a normalized result; determining the lambda correction value according to the normalized result and the direction control factor, where the lambda correction value is obtained by performing PID control on the product of the normalized result and the direction control factor.

[0122] Optionally, before determining the above lambda correction value according to the above normalization result and the above direction control factor, the above method further includes: determining the average speed and the average intake charge of the above engine according to the actual speed and the actual torque of the above engine; obtaining an amplitude correction factor, where the amplitude correction factor is the product of a plurality of correlation coefficients, and the correlation coefficients are at least one of the following: the aging correction coefficient of the above three-way catalytic converter, the correction coefficient of the post-treatment temperature, and the concentration correction coefficient of nitrogen oxides downstream of the above three-way catalytic converter; determining the proportional adjustment coefficient of the above PID control according to the above average speed and the above average intake charge, where the proportional adjustment coefficient is used to quickly adjust the error generated in the above PID control; determining the integral adjustment coefficient of the above PID control according to the above average speed, the above average intake charge, and the above amplitude correction factor, where the integral adjustment coefficient is used to adjust the steady-state time in the above PID control.

[0123] Optionally, after determining the lambda correction value according to the above specific emission target value, the above average specific emission value, and the direction control factor, and adaptively correcting the lambda to be corrected by using the above lambda correction value, the above method further includes: adaptively correcting the lambda to be corrected according to the above lambda correction value to obtain a corrected lambda value; applying the corrected lambda value to the next working condition, where the actual speed of the above engine in the next working condition is the same as the actual speed of the above engine in the current working condition and the actual torque of the above engine in the next working condition is the same as the actual torque of the above engine in the current working condition; obtaining the pollutant emission value under the same working condition after applying the corrected lambda value; and storing the corrected lambda value in a data table when the above pollutant emission value meets a preset condition.

[0124] An embodiment of the present invention provides a processor, where the processor is used to run a program, and when the program runs, it executes the above emission window correction method.

[0125] Specifically, the emission window correction method includes:

[0126] Step S2021, determining the current actual power according to the actual speed and the actual torque of the above engine;

[0127] Specifically, before starting the closed-loop correction, it is generally necessary to judge the working condition and the release condition, that is, to judge whether the current state of the engine can perform closed-loop correction. Specifically, the engine needs to maintain a steady state and have no faults;

[0128] Step S202: Determine the specific emission target value of the engine based on the actual speed and actual torque of the above-mentioned engine. The specific emission target value is the mass of pollutants emitted per unit time when the engine outputs unit output work.

[0129] Specifically, the current lambda to be corrected can be effectively corrected.

[0130] Step S203: Determine the average specific emission value of the engine based on the actual speed, actual torque, and emission flow rate of the above-mentioned engine. The average specific emission value is the average mass of pollutants actually emitted by the engine during a predetermined period when the engine outputs the above-mentioned unit output work.

[0131] Specifically, the average specific emission value of the engine under the current working condition can be accurately calculated.

[0132] Step S204: Determine the lambda correction value based on the above-mentioned specific emission target value, average specific emission value, and direction control factor, and adaptively correct the lambda to be corrected using the above-mentioned lambda correction value. Among them, the above-mentioned direction control factor is determined based on the above-mentioned oxygen content, and the direction control factor is a factor for controlling the correction direction of the lambda to be corrected. The lambda to be corrected is the current lambda emission window value of the above-mentioned three-way catalytic converter.

[0133] Specifically, the correction direction of the lambda to be corrected can be well controlled through the direction control factor.

[0134] Optionally, determining the specific emission target value of the engine based on the actual speed and actual torque of the above-mentioned engine includes: determining the current actual power based on the actual speed and actual torque of the above-mentioned engine; determining the cumulative work during a predetermined period and the duration of the above-mentioned predetermined period based on the above-mentioned current actual power. The cumulative work is obtained by integrating multiple above-mentioned current actual powers during the above-mentioned predetermined period; determining the average speed and average intake charge based on the above-mentioned cumulative work and the duration of the above-mentioned predetermined period. The average speed is the average speed of the engine during the above-mentioned predetermined period, and the average intake charge is the average intake charge of the engine during the above-mentioned predetermined period; determining the above-mentioned specific emission target value based on the above-mentioned average speed and average intake charge.

[0135] Optionally, determining the average specific emission value of the engine based on the actual rotation speed of the engine, the actual torque of the engine, and the emission flow rate of the engine includes: determining the cumulative work within the predetermined time period according to the current actual power, where the cumulative work is obtained by integrating a plurality of the current actual powers within the predetermined time period, and the current actual power is determined according to the actual rotation speed of the engine and the actual torque of the engine; integrating the emission flow rate within the predetermined time period to obtain the emission amount; and determining the average specific emission value according to the emission amount and the cumulative work, where the average specific emission value is the ratio of the emission amount to the cumulative work.

[0136] Optionally, the method further includes: when the oxygen content is less than or equal to a preset content, the direction control factor is a first type of direction factor, and the first type of direction factor is a negative value; when the oxygen content is greater than the preset content, the direction control factor is a second type of direction factor, and the second type of direction factor is a positive value.

[0137] Optionally, determining the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor includes: determining a correction deviation value according to the specific emission target value and the average specific emission value, where the correction deviation value is the difference between the specific emission target value and the average specific emission value; normalizing the correction deviation value to obtain a normalization result; and determining the lambda correction value according to the normalization result and the direction control factor, where the lambda correction value is obtained by performing PID control on the product of the normalization result and the direction control factor.

[0138] Optionally, before determining the lambda correction value according to the normalization result and the direction control factor, the method further includes: determining the average rotation speed of the engine and the average intake charge of the engine according to the actual rotation speed of the engine and the actual torque of the engine; obtaining an amplitude correction factor, where the amplitude correction factor is the product of a plurality of correlation coefficients, and the correlation coefficients are at least one of the following: the aging correction coefficient of the three-way catalyst, the correction coefficient of the post-treatment temperature, and the concentration correction coefficient of nitrogen oxides downstream of the three-way catalyst; determining the proportional adjustment coefficient of the PID control according to the average rotation speed and the average intake charge, where the proportional adjustment coefficient is used to quickly adjust the error generated in the PID control; and determining the integral adjustment coefficient of the PID control according to the average rotation speed, the average intake charge, and the amplitude correction factor, where the integral adjustment coefficient is used to adjust the steady-state time in the PID control.

[0139] Optionally, after determining the lambda correction value according to the above specific emission target value, the above average specific emission value, and the direction control factor, and adaptively correcting the lambda to be corrected using the above lambda correction value, the above method further includes: adaptively correcting the lambda to be corrected according to the above lambda correction value to obtain a corrected lambda value; applying the corrected lambda value to the next operating condition, where the true engine speed in the next operating condition is the same as the true engine speed in the current operating condition and the true engine torque in the next operating condition is the same as the true engine torque in the current operating condition; obtaining the pollutant emission value in the same operating condition after applying the corrected lambda value; and storing the corrected lambda value in a data table when the pollutant emission value meets a preset condition.

[0140] An embodiment of the present invention provides a device, which includes a processor, a memory, and a program stored on the memory and executable on the processor. When the processor executes the program, it implements at least the emission window correction method.

[0141] The device in this article can be a server, a PC, a PAD, a mobile phone, etc.

[0142] The present application also provides a computer program product, which, when executed on a data processing device, is adapted to execute a program initialized with steps of at least the emission window correction method:

[0143] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. They can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately made into individual integrated circuit modules, or multiple modules or steps of them can be made into a single integrated circuit module to implement. In this way, the present invention is not limited to any specific combination of hardware and software.

[0144] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0145] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0146] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0148] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0149] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of computer-readable media.

[0150] A computer-readable medium includes permanent and non-permanent, removable and non-removable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, 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, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information accessible by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0151] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0152] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0153] 1), In the above emission window correction method of the present application, first obtain the actual engine speed, actual engine torque, engine emission flow rate, and oxygen content in the engine pollutants under the current working condition; determine the specific emission target value of the engine according to the actual engine speed and actual engine torque; determine the average specific emission value of the engine according to the actual engine speed, actual engine torque, and engine emission flow rate; determine the lambda correction value according to the specific emission target value, average specific emission value, and direction control factor, and use the lambda correction value to adaptively correct the lambda to be corrected. This method adaptively corrects the lambda emission window of the three-way catalytic converter by using the average specific emission value and the specific emission target value, so that the lambda emission window remains in the optimal position during the aging process of the three-way catalytic converter, solves the problem in the prior art that the lambda window value in the engine cannot be adjusted and cannot reach the optimal efficiency after the three-way catalytic converter ages, and avoids the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions.

[0154] 2), The above-mentioned exhaust gas treatment system of the present application includes: a three-way catalytic converter; a nitrogen oxide sensor installed downstream of the three-way catalytic converter for obtaining the oxygen content in the pollutants of the engine; a controller communicatively connected to the three-way catalytic converter and the nitrogen oxide sensor for executing any one of the above-mentioned emission window correction methods. This system adaptively corrects the lambda emission window of the three-way catalytic converter using the average specific emission value and the specific emission target value, so that the lambda emission window remains in the optimal position during the aging process of the three-way catalytic converter, solving the problem in the prior art that the lambda window value in the engine cannot be adjusted and the best efficiency cannot be achieved after the three-way catalytic converter ages, and avoiding the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions.

[0155] 3), The above-mentioned controller of the present application includes an acquisition unit, a first determination unit, a second determination unit, and a correction unit. The acquisition unit is used to acquire the actual engine speed, the actual engine torque, the engine emission flow rate, and the oxygen content in the pollutants of the engine under the current working condition; the first determination unit is used to determine the specific emission target value of the engine according to the actual engine speed and the actual engine torque; the second determination unit is used to determine the average specific emission value of the engine according to the actual engine speed, the actual engine torque, and the engine emission flow rate; the correction unit is used to determine the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correct the lambda to be corrected using the lambda correction value. This controller adaptively corrects the lambda emission window of the three-way catalytic converter using the average specific emission value and the specific emission target value, so that the lambda emission window remains in the optimal position during the aging process of the three-way catalytic converter, solving the problem in the prior art that the lambda window value in the engine cannot be adjusted and the best efficiency cannot be achieved after the three-way catalytic converter ages, and avoiding the influence of problems such as poor aging consistency of the three-way catalytic converter on emissions.

[0156] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for correcting an emission window, characterized in that, Including: Obtain the actual engine speed, the actual engine torque, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current operating condition. The emission flow rate is the emission flow rate of the pollutants after being treated by the three-way catalyst, and the oxygen content is the oxygen content in the pollutants after being treated by the three-way catalyst; Determine the specific emission target value of the engine according to the actual engine speed and the actual engine torque. The specific emission target value is the mass of pollutants emitted per unit time when the engine outputs unit output work; Determine the average specific emission value of the engine according to the actual engine speed, the actual engine torque, and the emission flow rate of the engine. The average specific emission value is the average mass of pollutants actually emitted by the engine during a predetermined period when the engine outputs the unit output work; Determine the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correct the lambda to be corrected by using the lambda correction value. Wherein, the direction control factor is a factor for controlling the correction direction of the lambda to be corrected, and the lambda to be corrected is the lambda emission window value of the current three-way catalyst; 2. The correction method according to claim 1, wherein Determining the specific emission target value of the engine according to the actual engine speed and the actual engine torque includes: Determine the current actual power according to the actual engine speed and the actual engine torque; Determine the cumulative work within a predetermined period and the duration of the predetermined period according to the current actual power. The cumulative work is obtained by integrating multiple current actual powers within the predetermined period; Determine the average speed and the average intake charge according to the cumulative work and the duration of the predetermined period. The average speed is the average speed of the engine within the predetermined period, and the average intake charge is the average intake charge of the engine within the predetermined period; Determine the specific emission target value according to the average speed and the average intake charge; 3. The correction method according to claim 1, wherein Determining the average specific emission value of the engine according to the actual engine speed, the actual engine torque, and the emission flow rate of the engine includes: Determine the cumulative work within the predetermined period according to the current actual power. The cumulative work is obtained by integrating multiple current actual powers within the predetermined period, wherein the current actual power is determined according to the actual engine speed and the actual engine torque; Integrate the emission flow rate within the predetermined period to obtain the emission amount; Determine the average specific emission value according to the emission amount and the cumulative work. The average specific emission value is the ratio of the emission amount to the cumulative work; 4. The correction method according to claim 1, characterized in that The method further includes: When the oxygen content is less than or equal to the preset content, the direction control factor is a first type direction factor, and the first type direction factor is a negative value; When the oxygen content is greater than the preset content, the direction control factor is a second type of direction factor, and the second type of direction factor is a positive value.

5. The correction method according to claim 1, characterized in that Determining a lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor includes: Determining a correction deviation value according to the specific emission target value and the average specific emission value, where the correction deviation value is the difference between the specific emission target value and the average specific emission value; Performing normalization processing on the correction deviation value to obtain a normalization result; Determining the lambda correction value according to the normalization result and the direction control factor, where the lambda correction value is obtained by performing PID control on the product of the normalization result and the direction control factor.

6. The correction method according to claim 5, characterized in that Before determining the lambda correction value according to the normalization result and the direction control factor, the method further includes: Determining the average engine speed and the average intake charge of the engine according to the actual engine speed and the actual engine torque of the engine; Obtaining an amplitude correction factor, where the amplitude correction factor is the product of multiple correlation coefficients, and the correlation coefficients are at least one of the following: the aging correction coefficient of the three-way catalytic converter, the correction coefficient of the post-treatment temperature, and the concentration correction coefficient of nitrogen oxides downstream of the three-way catalytic converter; Determining a proportional regulation coefficient of the PID control according to the average engine speed and the average intake charge, where the proportional regulation coefficient is used to quickly adjust the error generated in the PID control; Determining an integral regulation coefficient of the PID control according to the average engine speed, the average intake charge, and the amplitude correction factor, where the integral regulation coefficient is used to adjust the steady-state time in the PID control.

7. The correction method according to any one of claims 1 to 6, characterized in that After determining the lambda correction value according to the specific emission target value, the average specific emission value, and the direction control factor, and adaptively correcting the lambda to be corrected by using the lambda correction value, the method further includes: Adapting and correcting the lambda to be corrected according to the lambda correction value to obtain a corrected lambda value; Applying the corrected lambda value to the next working condition, where the actual engine speed in the next working condition is the same as the actual engine speed in the current working condition, and the actual engine torque in the next working condition is the same as the actual engine torque in the current working condition; Obtaining the pollutant emission value under the same working condition to which the corrected lambda value is applied; When the pollutant emission value meets the preset conditions, storing the corrected lambda value in a data table.

8. An exhaust gas treatment system, characterized in that, Including: Three-way catalytic converter; A nitrogen oxygen sensor, installed downstream of the three-way catalytic converter, for obtaining the oxygen content in the pollutants of the engine; A controller, communicatively connected to the three-way catalytic converter and the nitrogen oxygen sensor, for executing the emission window correction method according to any one of claims 1 to 7.

9. A controller, characterized in that, Including: An acquisition unit for acquiring the actual engine speed, the actual engine torque, the emission flow rate of the engine, and the oxygen content in the pollutants of the engine under the current working condition, where the emission flow rate is the emission flow rate of the pollutants after being treated by a three-way catalytic converter, and the oxygen content is the oxygen content in the pollutants after being treated by the three-way catalytic converter; A first determination unit for determining a specific emission target value of the engine according to the actual engine speed and the actual engine torque, where the specific emission target value is the mass of pollutants emitted per unit time when the engine outputs a unit of output work; A second determination unit for determining an average specific emission value of the engine according to the actual engine speed, the actual engine torque, and the emission flow rate of the engine, where the average specific emission value is the average mass of pollutants actually emitted by the engine within a predetermined time period when the engine outputs the unit of output work; A correction unit for determining a lambda correction value according to the specific emission target value, the average specific emission value, and a direction control factor, and adaptively correcting the lambda to be corrected by using the lambda correction value, where the direction control factor is determined according to the oxygen content, the direction control factor is a factor for controlling the correction direction of the lambda to be corrected, and the lambda to be corrected is the lambda emission window value of the current three-way catalytic converter.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, where, when the program runs, it controls the device where the computer-readable storage medium is located to execute the emission window correction method according to any one of claims 1 to 7.

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