A diesel engine control method, device, equipment and storage medium

Abstract

The application discloses a diesel engine control method, device, equipment and storage medium. The method comprises the following steps: establishing a maximum nitrogen oxide original emission allowance predictor according to the actual efficiency of a preset selective catalytic reduction device (SCR), the current temperature of the SCR, the current exhaust volume, the expected ammonia nitrogen ratio and the downstream emission limit value, so as to determine the maximum original emission value allowed by the diesel engine; determining the emission volume deviation and the fuel consumption proportion coefficient according to the engine speed, the fuel injection volume and the emission proportion coefficient of the diesel engine; determining the candidate proportion coefficient corresponding to the maximum original emission value, and determining the target fuel injection time and the target rail pressure according to the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient, as well as the candidate fuel injection time and the candidate rail pressure; and performing adaptive control on the ammonia nitrogen ratio of the diesel engine, and performing fuel injection control on the diesel engine in combination with the target fuel injection time and the target rail pressure. The optimal emission control of the diesel engine can be realized, and the diesel engine is helped to save fuel.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile engine control, and in particular to a diesel engine control method, device, equipment and storage medium. BACKGROUND

[0002] Due to a large amount of harmful substances generated during the cold start process of the automobile, in order to reduce the harm to the human body, there are clear regulations in the emission limit of the starting process. However, the combustion temperature is not high during the cold start, and the exhaust gas recirculation does not play a big role, but hinders the combustion, so that the combustion is deteriorated, and the soot and fuel consumption problems come with it.

[0003] Therefore, how to effectively control the ammonia nitrogen ratio emission and the injection mode of the diesel engine, while reducing the nitrogen oxide emission, rapidly improving the exhaust temperature, and realizing the optimal control of the emission and fuel consumption, is a problem to be solved at present. SUMMARY

[0004] The present application provides a diesel engine control method, device, equipment and storage medium, which can realize the optimal emission control of the diesel engine, and is helpful to the fuel saving of the diesel engine.

[0005] According to one aspect of the present application, a diesel engine control method is provided, comprising:

[0006] According to the actual efficiency of the preset selective catalytic conversion device SCR, the current temperature of the SCR, the current exhaust gas volume, the expected ammonia nitrogen ratio and the downstream emission limit value, a maximum nitrogen oxide original emission allowed emission predictor is established to determine the maximum original emission value allowed to be emitted by the diesel engine;

[0007] According to the engine speed, the injection amount and the emission proportion coefficient of the diesel engine, the emission amount deviation and the fuel consumption proportion coefficient are determined;

[0008] The candidate proportion coefficient corresponding to the maximum original emission value is determined, and the target injection time and the target rail pressure are determined according to the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient, and the preset high, medium and low three different levels corresponding to the candidate injection time and the candidate rail pressure;

[0009] According to the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient, the adaptive control of the ammonia nitrogen ratio of the diesel engine is carried out, and according to the target injection time and the target rail pressure, the injection control of the diesel engine is carried out.

[0010] According to another aspect of the present application, a diesel engine control device is provided, comprising:

[0011] The original emission determination module is configured to determine the maximum original emission value of the diesel engine according to the maximum nitrogen oxide original emission prediction value.

[0012] The coefficient determination module is configured to determine the emission deviation and the fuel consumption proportion coefficient according to the engine speed, the fuel injection amount and the emission proportion coefficient of the diesel engine.

[0013] The target determination module is configured to determine the candidate proportion coefficient corresponding to the maximum original emission value, and determine the target fuel injection time and the target rail pressure according to the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient, and the candidate fuel injection time and the candidate rail pressure corresponding to the preset high, medium and low three different levels.

[0014] The control module is configured to perform the adaptive control of the ammonia nitrogen ratio of the diesel engine according to the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient, and perform the fuel injection control of the diesel engine according to the target fuel injection time and the target rail pressure.

[0015] According to another aspect of the present application, an electronic device is provided, the electronic device comprising:

[0016] at least one processor; and

[0017] a memory communicatively connected with the at least one processor; wherein

[0018] the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the diesel engine control method according to any one of the embodiments of the present application.

[0019] According to another aspect of the present application, a computer readable storage medium is provided, the computer readable storage medium stores computer instructions for enabling a processor to perform the diesel engine control method according to any one of the embodiments of the present application when executed by the processor.

[0020] The technical scheme of the embodiment of the present application establishes a maximum nitrogen oxide original emission allowance predictor according to the actual efficiency of a preset selective catalytic reduction device SCR, the current temperature of the SCR, the current exhaust volume, the expected ammonia nitrogen ratio and the downstream emission limit value, to determine the maximum original emission value allowed to be emitted by the diesel engine; determines the emission volume deviation and the oil consumption proportion coefficient according to the engine speed, the fuel injection volume and the emission proportion coefficient of the diesel engine; determines the candidate proportion coefficient corresponding to the maximum original emission value, and determines the target fuel injection time and the target rail pressure according to the candidate proportion coefficient, the emission proportion coefficient and the oil consumption proportion coefficient, and the candidate fuel injection time and the candidate rail pressure; performs adaptive control of the ammonia nitrogen ratio of the diesel engine, and performs fuel injection control of the diesel engine in combination with the target fuel injection time and the target rail pressure. The optimal emission control of the diesel engine can be realized, which is helpful for oil saving of the diesel engine.

[0021] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 is a flow chart of a diesel engine control method provided by the first embodiment of the present application;

[0024] Figure 2 is a flow chart of a diesel engine control method provided by the second embodiment of the present application;

[0025] Figure 3 is a structural block diagram of a diesel engine control device provided by the third embodiment of the present application;

[0026] Figure 4 is a structural schematic diagram of an electronic device provided by the fourth embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0028] It is to be understood that the terms "first", "second", "target", "candidate", "alternative", etc. in the description and claims of the application and above drawings are used to distinguish similar objects, and are not necessarily used to describe a particular sequential or chronological order. It should be understood that the data thus used can be interchanged, where appropriate, so that the embodiments of the application described herein can be carried out in other than the order shown or described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or apparatus that comprises a list of steps or units not necessarily limited to those explicitly listed, but can include other steps or units not expressly listed or inherent to such processes, methods, products or apparatus.

[0029] Embodiment one

[0030] Figure 1 is a flow chart of a diesel engine control method provided by the first embodiment of the application; the embodiment can be applicable to control the ammonia nitrogen ratio emission and oil emission of the diesel engine to achieve the optimal emission and loss condition, the method can be executed by a diesel engine control device, which can be realized in the form of hardware and / or software, and can be configured in an electronic device, such as a car. As shown in the figure, the diesel engine control method comprises: Figure 1

[0031] S101, according to the actual efficiency of the pre-set selective catalytic conversion device SCR, the current temperature of SCR, the current exhaust volume, the expected ammonia nitrogen ratio and the downstream emission limit value, a maximum nitrogen oxide original emission allowed emission predictor is established to determine the maximum original emission value allowed to be emitted by the diesel engine.

[0032] Among them, the selective catalytic conversion device (Selective Catalytic Reduction, SCR) is a processing device for NOx (nitrogen oxide) in the exhaust emission of diesel vehicles. The maximum nitrogen oxide original emission allowed emission predictor is used to predict the maximum amount of nitrogen oxide allowed to be emitted. The maximum original emission value refers to the maximum amount of nitrogen oxide allowed to be emitted by the diesel engine, which can be represented by MaxEmiEO.

[0033] ​Optionally, the maximum nitrogen oxide raw emission allowable emission predictor is established to determine the maximum raw emission value of the allowable emission of the diesel engine, including: collecting data by using the upstream and downstream nitrogen oxide sensors, and determining the actual efficiency of the preset selective catalytic reduction device SCR according to the collection result; determining the efficiency estimation value according to the current temperature of the SCR, the current exhaust volume and the expected ammonia nitrogen ratio; estimating the aftertreatment efficiency of the diesel engine according to the first-order inertia delay relationship between the efficiency estimation value and the actual efficiency; and determining the maximum raw emission value of the allowable emission according to the aftertreatment efficiency and the downstream emission limit value.

[0034] The downstream emission limit value refers to the upper limit value of the amount of nitrogen oxide in the operation emission of the preset downstream nitrogen oxide sensor, which can be represented by LimitEmiTP.

[0035] Optionally, the upstream and downstream nitrogen oxide sensors can be used to perform preset low-pass filtering operation and nitrogen oxide collection operation on the nitrogen oxide emission of the diesel engine, to obtain the tailpipe emission nitrogen oxide amount and the raw emission nitrogen oxide amount under the current working condition; and the actual efficiency of the preset selective catalytic reduction device SCR is calculated according to the tailpipe emission nitrogen oxide amount and the raw emission nitrogen oxide amount.

[0036] For example, the actual efficiency Eff of the preset selective catalytic reduction device SCR can be determined based on the following formula: act :

[0037] Eff act = 1-NOx TP / NOx EO

[0038] Wherein, NOx TP is the tailpipe emission nitrogen oxide amount, NOx EO is the raw emission nitrogen oxide amount, and Eff act is the actual efficiency of the preset selective catalytic reduction device SCR.

[0039] For example, the efficiency estimation value Eff eva can be determined based on the following formula:

[0040] Eff eva = f(T scr ,V ex ,Ratio NH3NOx )

[0041] Wherein, T scr is the average value of the current temperature of the upstream and downstream nitrogen oxide sensors SCR (i.e. the current temperature of the SCR is determined by two sensors and then averaged), V ex is the current exhaust volume, and Ratio NH3NOxFor the expected ammonia nitrogen ratio, specifically, the ratio of the current urea injection molar amount to the current original exhaust NOx estimation amount can be determined as the expected ammonia nitrogen ratio. f() is a preset data fitting polynomial.

[0042] Exemplarily, since there is a first-order inertial delay between the efficiency estimation value and the actual efficiency, a connection between the two can be established by establishing a state space equation, in which x represents the recursion of the state, and y represents the calculation of the result. Specifically, the output y(k) of the state space equation at time k can be determined based on the efficiency estimation value and the actual efficiency according to the following formula:

[0043] y(k)=[Eff act Eff eva ] T

[0044] wherein Eff act is the actual efficiency. Eff eva is the efficiency estimation value.

[0045] Exemplarily, after determining the output y(k) of the state space equation at time k, the input x(k) of the state space equation at time k can be back calculated based on the following formula:

[0046] y(k)=Cx(k)+η(k)

[0047] wherein C is an observation matrix, and η is measurement noise.

[0048] Further, the aftertreatment efficiency of the diesel engine can be determined based on the following formula:

[0049]

[0050] wherein y(k) is the output of the state space equation at time k, x(k) is the input of the state space equation at time k, C F is a first coefficient. D F is a second coefficient. The first coefficient C F and the second coefficient D F can be determined by the following formula:

[0051] C F =[1 0 0](A-AKC)

[0052] D F =[1 0 0]AK

[0053] wherein A is a state transition matrix, C is an observation matrix, and K is a Kalman filter number, which can be determined by the following formula:

[0054]

[0055]

[0056]

[0057] wherein a is a tunable quantity, and H is a preset constant matrix, such as H = [0 1 0; 1 0 1]. P k The stable value is iteratively obtained by the following formula, specifically by R k and Q k The online debugging matrix is used to adjust the model to a good state, without the need for online iterative solution.

[0058]

[0059] Exemplarily, the maximum original emission value allowed to be emitted can be determined according to the post-processing efficiency and the downstream emission limit value by the following formula:

[0060]

[0061] wherein MaxEmiEO is the maximum original emission value allowed to be emitted, LimitEmiTP is the downstream emission limit value, is the post-processing efficiency.

[0062] S102, determining an emission amount deviation and an oil consumption proportion coefficient according to the engine speed, the fuel injection amount, and an emission proportion coefficient of the diesel engine.

[0063] The emission proportion coefficient refers to a coefficient representing the proportional relationship between the actual fuel injection time of the diesel engine and the fuel injection time corresponding to the preset emission level. The emission amount deviation refers to the deviation of the emission amount between the diesel engine emission value and the preset level emission value.

[0064] Optionally, the emission amount deviation is determined according to the engine speed, the fuel injection amount, and the emission proportion coefficient of the diesel engine, including: performing an emission table lookup operation according to the engine speed and the fuel injection amount to determine a second-order emission coefficient and a first-order emission coefficient; determining the emission proportion coefficient of the diesel engine based on a linear interpolation manner according to the relationship between the actual fuel injection time and the fuel injection time corresponding to the preset emission level; and determining the emission amount deviation between the diesel engine emission value and the preset level emission value according to the second-order emission coefficient, the first-order emission coefficient, and the emission proportion coefficient.

[0065] The fuel injection amount may be, for example, the fuel injection amount of the diesel engine in a historical preset time period. The actual fuel injection time may be, for example, the fuel injection time of the diesel engine in each preset time period in history, such as the actual fuel injection time of the diesel engine in the previous second. The preset emission level may be, for example, the medium emission level and the highest emission level among the preset low, medium, and high three emission levels.

[0066] Exemplarily, the emission deviation ΔEmi can be determined based on the following formula: EO :

[0067] ΔEmi EO =A*x1 2 +B*x1

[0068] wherein A is a second-order coefficient of emission, B is a first-order coefficient of emission, x1 is a coefficient of emission proportion, and the value range of x1 is 0-1, which is a linear interpolation result between the injection time corresponding to the medium emission level and the injection time corresponding to the highest emission level according to the actual injection time.

[0069] Optionally, the coefficient of fuel consumption proportion is determined by: performing a fuel consumption table lookup operation according to the engine speed and the injection amount to determine a second-order coefficient of fuel consumption and a first-order coefficient of fuel consumption; establishing a cost deviation equation according to the exhaust mass flow, the exhaust molar mass, the emission deviation, an expected ammonia-nitrogen ratio, a calibration parameter, and the engine speed, and making the cost deviation take a preset value to determine a fuel consumption deviation between the diesel engine fuel consumption value and a preset level fuel consumption value; and determining the coefficient of fuel consumption proportion according to the fuel consumption deviation, the second-order coefficient of fuel consumption, and the first-order coefficient of fuel consumption. The preset value can be 0, for example.

[0070] Exemplarily, the cost deviation equation can be as follows:

[0071]

[0072] wherein Mf is the exhaust mass flow, M is the exhaust molar mass, ΔEmi is the emission deviation, Ratio is the expected ammonia-nitrogen ratio, fac is the calibration parameter, N is the engine speed, and ΔCost is the cost deviation. ex ex EO NH3NOx e

[0073] Optionally, the cost deviation can be made to take 0 to determine the fuel consumption deviation ΔQ fuel , and the coefficient of fuel consumption proportion x2 is further determined based on the following formula:

[0074] ΔQ fuel =C*x2 2 +D*x2

[0075] wherein C is a second-order coefficient of fuel consumption, and D is a first-order coefficient of fuel consumption.

[0076] ​​​​​S103, determine the candidate proportional coefficient corresponding to the maximum original emission value, and determine the target injection timing and the target rail pressure according to the candidate proportional coefficient, the emission proportional coefficient and the fuel consumption proportional coefficient, and the candidate injection timing and the candidate rail pressure corresponding to the preset high, medium and low three different levels.

[0077] The candidate proportional coefficient can represent the proportional relationship between the maximum original emission value and the target emission value corresponding to the preset high, medium and low three different levels, and can be denoted by wt.

[0078] Optionally, the candidate proportional coefficient corresponding to the maximum original emission value is determined, including: determining the corresponding compensation value for the candidate emission value of the preset high, medium and low three different levels according to the environment temperature lookup table, the environment pressure lookup table, the water temperature lookup table and the target air-fuel ratio deviation lookup table; determining the target emission value corresponding to the high, medium and low three different levels by adding the candidate emission value of the preset high, medium and low three different levels to the compensation value respectively; determining the candidate proportional coefficient corresponding to the maximum original emission value based on the linear interpolation method according to the relationship between the maximum original emission value and the target emission value of the preset high, medium and low three different levels.

[0079] Optionally, the target injection timing and the target rail pressure are determined, including: determining the target proportional coefficient as the minimum value in the candidate proportional coefficient, the emission proportional coefficient and the fuel consumption proportional coefficient; obtaining the target injection timing and the target rail pressure based on the linear interpolation method according to the target proportional coefficient and the candidate injection timing and the candidate rail pressure corresponding to the preset high, medium and low three different levels.

[0080] Optionally, the target injection timing can be obtained based on the linear interpolation method according to the target proportional coefficient and the candidate injection timing corresponding to the preset high, medium and low three different levels, and the target rail pressure can be obtained based on the linear interpolation method according to the target proportional coefficient and the candidate rail pressure corresponding to the preset high, medium and low three different levels.

[0081] S104, adaptive control of the ammonia-nitrogen ratio of the diesel engine is performed according to the candidate proportional coefficient, the emission proportional coefficient and the fuel consumption proportional coefficient, and injection control of the diesel engine is performed according to the target injection timing and the target rail pressure.

[0082] The adaptive control of the ammonia-nitrogen ratio of the diesel engine includes feedforward control and feedback control.

[0083] Optionally, the adaptive control of the ammonia-nitrogen ratio of the diesel engine includes: performing feedforward control of the ammonia-nitrogen ratio of the diesel engine according to the exhaust air speed and the current temperature of the SCR; determining the weight deviation according to the candidate proportional coefficient, the emission proportional coefficient and the fuel consumption proportional coefficient, and performing feedback control of the ammonia-nitrogen ratio of the diesel engine according to the weight deviation.

[0084] Optionally, the exhaust air speed and the current SCR temperature can be taken as inputs to perform feedforward control of the ammonia nitrogen ratio of the diesel engine, to determine a basic target ammonia nitrogen ratio feedforward value, which is essentially a calibrated number table.

[0085] Optionally, the sum of the deviations between the candidate proportionality coefficient, the emission proportionality coefficient and the fuel consumption proportionality coefficient can be determined as a final weight deviation, and the weight deviation is further subjected to a PI (proportional integral) link to perform feedback control of the ammonia nitrogen ratio of the diesel engine, to obtain a feedback value.

[0086] Optionally, the final target ammonia nitrogen ratio can be obtained according to the feedforward value and the feedback value, and the diesel engine emission control can be performed according to the target ammonia nitrogen ratio.

[0087] Optionally, the target ammonia nitrogen ratio can be adjusted by performing adaptive control of the ammonia nitrogen ratio of the diesel engine, to achieve diesel engine emission compliance, determine the optimal fuel consumption and urea comprehensive consumption, and realize optimal emission and fuel consumption of the diesel engine under cold start, steady state and transient state conditions. According to the target injection time and the target rail pressure, the diesel engine is injected at the target injection time under the target rail pressure, to realize injection control of the diesel engine.

[0088] It should be noted that the injection control of the diesel engine is performed by determining the target injection time and the target rail pressure, which can delay the injection time as much as possible. The delayed injection time is helpful in the cold start process. The combustion of diesel fuel injected late produces lower nitrogen oxides. In combination with lower common rail pressure and the use of multiple post-injection methods, the nitrogen oxide emission is reduced while the exhaust temperature is rapidly increased, which maximizes the emission reduction, thereby realizing optimal control of the emission and fuel consumption and oil saving of the diesel engine.

[0089] The technical scheme of the embodiment of the present application establishes a maximum nitrogen oxide original emission allowance predictor according to the actual efficiency of the preset selective catalytic conversion device SCR, the current SCR temperature, the current exhaust volume, the expected ammonia nitrogen ratio and the downstream emission limit value, to determine the maximum original emission value allowed to be emitted by the diesel engine; determines the emission volume deviation and the fuel consumption proportionality coefficient according to the engine speed, the injection amount and the emission proportionality coefficient of the diesel engine; determines the candidate proportionality coefficient corresponding to the maximum original emission value, and determines the target injection time and the target rail pressure according to the candidate proportionality coefficient, the emission proportionality coefficient and the fuel consumption proportionality coefficient, and the candidate injection time and the candidate rail pressure; performs adaptive control of the ammonia nitrogen ratio of the diesel engine, and performs injection control of the diesel engine in combination with the target injection time and the target rail pressure. The optimal emission control of the diesel engine can be realized, which is helpful for oil saving of the diesel engine.

[0090] Embodiment two

[0091] Figure 2is a flow chart of a diesel engine control method provided by Embodiment Two of the present application; based on the above technical solutions, this embodiment gives an optimal example of diesel engine control based on an allowable original emission estimator, an online fuel-urea optimizer, and a comprehensive controller. As shown in Figure 2 The diesel engine control method can specifically include the following processes:

[0092] (1) According to the current upstream and downstream NOx sensor filtered (such as low-pass filtered) values, the current SCR actual efficiency, i.e., the current efficiency, is calculated. According to the SCR current temperature and exhaust volume and the expected ammonia-nitrogen ratio, the efficiency estimation value, i.e., the estimated efficiency, is calculated.

[0093] (2) The current efficiency and the estimated efficiency are input into the allowable original emission estimator after Kalman filtering, to perform the operation of determining the maximum original emission value as described in the above embodiments of the present application, to obtain the maximum allowable emission value and input the comprehensive controller.

[0094] (3) Establishing a fuel-urea online optimizer

[0095] The fuel consumption and urea consumption are in a fluctuating relationship, and therefore there is an optimal compromise value that makes the comprehensive price calculated based on the fuel price and the urea price the lowest. The online optimizer is in the following form:

[0096] The target rail pressure and injection timing at three emission levels can be set, so that under the same operating point, three different emission results of high, medium, and low can be generated, wherein the target rail pressure and injection timing corresponding to the medium emission level are the default target values. Two charts are calibrated to correspond to the second-order term coefficient and the first-order term coefficient, and this coefficient is obtained by looking up the engine speed and injection amount table.

[0097] Through the establishment of the fuel-urea online optimizer, the emission proportion coefficient and the fuel consumption proportion coefficient can be obtained to input the comprehensive controller for control.

[0098] (4) Ammonia-nitrogen ratio self-adaptation

[0099] Through the self-adaptive control process of the ammonia-nitrogen ratio, the optimal target ammonia-nitrogen ratio can be obtained to input the comprehensive controller for control.

[0100] It should be noted that by adjusting the ammonia-nitrogen ratio, the optimal urea injection amount is achieved, and thus the urea injection amount is reduced when a high aftertreatment efficiency is not required, thereby achieving the purpose of saving urea and reducing fuel consumption.

[0101] (5) Comprehensive controller

[0102] The operation of determining the target fuel injection time and the target rail pressure described in the above embodiments of the application can be performed based on the maximum original emission value, the emission proportion coefficient and the fuel consumption proportion coefficient to obtain the target fuel injection time and the rail pressure (i.e. the target rail pressure), and combined with adaptive control of the ammonia nitrogen ratio, diesel engine control is performed.

[0103] The technical scheme of the application, by establishing a post-processing efficiency predictor based on Kalman filtering, calculating the current efficiency and the estimated efficiency through actual acquisition by a sensor, and using a Kalman filter to establish a connection, the future generated post-processing efficiency value can be estimated in advance, effectively solving the time delay problem of the control quantity and the sensor value, making the system more accurately controlled; by calculating the current efficiency and the estimated efficiency through actual acquisition by a sensor, and using a Kalman filter to establish a connection, the future generated post-processing efficiency value can be estimated in advance.

[0104] By establishing a fuel and urea consumption online optimizer, the contradiction between fuel consumption and urea consumption is solved, the best compromise value is calculated, and the comprehensive price calculated after the fuel price and the urea price is the lowest; by fitting the relationship between the emission and fuel consumption deviation and the control proportion, the nonlinear change of fuel consumption and emission can be effectively reflected and the extreme point can be found, considering the market price change of urea and fuel, the parameter is easy to calibrate; by the fuel and urea consumption online optimizer, the comprehensive price calculated after the fuel price and the urea price is the lowest; by fitting the relationship between the emission and fuel consumption deviation and the control proportion, the nonlinear change of fuel consumption and emission can be effectively reflected and the extreme point can be found.

[0105] By interpolating a proportion coefficient between the maximum original emission value and three different emission values of high, medium and low, a proportion coefficient of 0-1 is calculated in a linear interpolation manner, and the compensation is performed in an accumulated manner, the compensation amount includes looking up tables according to the ambient temperature, the ambient pressure, the water temperature and the target air-fuel ratio deviation, the table calculation values are added in turn, the proportion coefficient is compared with the proportion coefficient of the optimal fuel consumption and emission to take the smaller value, and the optimal proportion coefficient can be determined.

[0106] The deviation between the proportion coefficient calculated by the maximum emission value and the proportion coefficient calculated by the online optimal estimator is a PI link, which is added to the target ammonia nitrogen ratio basic calculation value as a deviation, the basic calculation value is calculated by the exhaust air speed and the SCR temperature, and the optimal urea injection amount is realized by adjusting the ammonia nitrogen ratio.

[0107] Embodiment three

[0108] Figure 3is a structural block diagram of a diesel engine control device provided by embodiment three of the present application; the embodiment can be applicable to control of ammonia nitrogen ratio emission and oil emission of a diesel engine to achieve optimal emission and loss conditions, the diesel engine control device can be realized in the form of hardware and / or software and configured in a device with diesel engine control function, such as a car. Figure 3 As shown in the figure, the diesel engine control device specifically comprises:

[0109] A raw emission determination module 301 is configured to establish a maximum nitrogen oxide raw emission allowable emission predictor according to a preset actual efficiency of a selective catalytic reduction device SCR, a current temperature of the SCR, a current exhaust gas volume, an expected ammonia nitrogen ratio and a downstream emission limit value, so as to determine a maximum raw emission value allowed to be emitted by the diesel engine;

[0110] A coefficient determination module 302 is configured to determine an emission amount deviation and an oil consumption proportion coefficient according to an engine speed, an injection amount and an emission proportion coefficient of the diesel engine;

[0111] A target determination module 303 is configured to determine a candidate proportion coefficient corresponding to the maximum raw emission value, and determine a target injection time and a target rail pressure according to the candidate proportion coefficient, the emission proportion coefficient and the oil consumption proportion coefficient, and preset candidate injection times and candidate rail pressures corresponding to three different levels of high, medium and low;

[0112] A control module 304 is configured to perform adaptive control of ammonia nitrogen ratio of the diesel engine according to the candidate proportion coefficient, the emission proportion coefficient and the oil consumption proportion coefficient, and perform injection control of the diesel engine according to the target injection time and the target rail pressure.

[0113] The technical scheme of the embodiment of the present application establishes a maximum nitrogen oxide raw emission allowable emission predictor according to a preset actual efficiency of a selective catalytic reduction device SCR, a current temperature of the SCR, a current exhaust gas volume, an expected ammonia nitrogen ratio and a downstream emission limit value, so as to determine a maximum raw emission value allowed to be emitted by the diesel engine; determines an emission amount deviation and an oil consumption proportion coefficient according to an engine speed, an injection amount and an emission proportion coefficient of the diesel engine; determines a candidate proportion coefficient corresponding to the maximum raw emission value, and determines a target injection time and a target rail pressure according to the candidate proportion coefficient, the emission proportion coefficient and the oil consumption proportion coefficient, and preset candidate injection times and candidate rail pressures corresponding to three different levels of high, medium and low; performs adaptive control of ammonia nitrogen ratio of the diesel engine, and performs injection control of the diesel engine in combination with the target injection time and the target rail pressure. The optimal emission control of the diesel engine can be realized, which is helpful for oil saving of the diesel engine.

[0114] Further, the raw emission determination module 301 is specifically configured to:

[0115] Data acquisition is performed by using upstream and downstream nitrogen oxide sensors, and the preset actual efficiency of the selective catalytic reduction device SCR is determined according to the acquisition result;

[0116] determine an efficiency estimate according to the current temperature of the SCR, the current exhaust flow, and the expected ammonia-to-nitrogen ratio;

[0117] estimate the aftertreatment efficiency of the diesel engine according to a first-order inertial delay relationship between the efficiency estimate and the actual efficiency;

[0118] determine the maximum raw emission value of the allowed emission according to the aftertreatment efficiency and the downstream emission limit value.

[0119] Further, the coefficient determination module 302 is specifically configured to:

[0120] perform an emission table lookup operation according to the engine speed and the fuel injection amount to determine an emission second-order term coefficient and an emission first-order term coefficient; determine an emission proportion coefficient of the diesel engine based on a linear interpolation manner according to a relationship between an actual fuel injection time and a fuel injection time corresponding to a preset emission level; and determine an emission amount deviation between the diesel engine emission value and the preset level emission value according to the emission second-order term coefficient, the emission first-order term coefficient, and the emission proportion coefficient.

[0121] Further, the coefficient determination module 302 is further configured to:

[0122] perform a fuel consumption table lookup operation according to the engine speed and the fuel injection amount to determine a fuel consumption second-order term coefficient and a fuel consumption first-order term coefficient; establish a cost deviation equation according to the exhaust mass flow, the exhaust molar mass, the emission amount deviation, the expected ammonia-to-nitrogen ratio, the calibration parameter, and the engine speed, and make the cost deviation take a preset value to determine a fuel consumption deviation between the diesel engine fuel consumption value and the preset level fuel consumption value; and determine a fuel consumption proportion coefficient according to the fuel consumption deviation, the fuel consumption second-order term coefficient, and the fuel consumption first-order term coefficient.

[0123] Further, the target determination module 303 is specifically configured to:

[0124] determine corresponding compensation values for preset high, medium, and low three different levels of candidate emission values according to an ambient temperature lookup table, an ambient pressure lookup table, a water temperature lookup table, and a target air-fuel ratio deviation lookup table; determine high, medium, and low three different levels of corresponding target emission values by adding the preset high, medium, and low three different levels of candidate emission values to the compensation values, respectively; and determine a candidate proportion coefficient corresponding to the maximum raw emission value based on a linear interpolation manner according to a relationship between the maximum raw emission value and the preset high, medium, and low three different target emission values.

[0125] Further, the target determination module 303 is further configured to:

[0126] The minimum value among the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient is determined as a target proportion coefficient; according to the target proportion coefficient, and the candidate injection timing and the candidate rail pressure corresponding to the three different levels of high, medium and low, the target injection timing and the target rail pressure are obtained based on a linear interpolation manner.

[0127] Further, the control module 304 is specifically configured to:

[0128] According to the exhaust air speed and the current temperature of the SCR, the feedforward control of the ammonia nitrogen ratio of the diesel engine is performed; according to the candidate proportion coefficient, the emission proportion coefficient and the fuel consumption proportion coefficient, the weight deviation is determined, and according to the weight deviation, the feedback control of the ammonia nitrogen ratio of the diesel engine is performed.

[0129] Embodiment four

[0130] Figure 4 is a structural schematic diagram of an electronic device provided by the embodiment four of the present application. Figure 4 A structural schematic diagram of an electronic device 10 that can be used to implement embodiments of the present application is shown. The electronic device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular telephones, smartphones, wearable devices (e.g., headsets, glasses, watches, etc.), and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be examples only, and are not intended to limit the implementations of the present application described and / or claimed in this document.

[0131] As shown in Figure 4 The electronic device 10 includes at least one processor 11, and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., which are in communication with the at least one processor 11, wherein the memory stores a computer program that can be executed by the at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12 and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0132] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0133] The processor 11 can be various general and / or special purpose processing components having processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs various methods and processes described above, such as the diesel engine control method.

[0134] In some embodiments, the diesel engine control method can be implemented as a computer program tangibly embodied in a computer readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded onto the RAM 13 and executed by the processor 11, one or more steps of the diesel engine control method described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the diesel engine control method by any other appropriate means, such as by means of firmware.

[0135] Various implementations of the systems and techniques described above can be realized in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a programmable logic device (PLD), a computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0136] Computer programs for implementing the methods of the present application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer program, when executed, can cause instructions defined in the flow charts and / or block diagrams to be implemented. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a stand-alone software package, and partially on a remote machine or entirely on a remote machine or server.

[0137] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0138] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0139] The systems and techniques described herein can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described herein, or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0140] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0141] It should be understood that the various forms of flow shown above can be re-ordered, added to, or deleted from without departing from the scope of the present disclosure. For example, the steps recited in the present disclosure can be executed in parallel, executed in series, or executed in different orders, as long as the desired results of the technical solutions of the present disclosure can be achieved, and the present disclosure is not limited herein.

[0142] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A diesel engine control method characterized by, The method comprises the following steps: According to the actual efficiency of the preset selective catalytic reduction device SCR, the current temperature of the SCR, the current exhaust volume, the expected ammonia-nitrogen ratio, and the downstream emission limit value, a maximum nitrogen oxide raw emission allowable emission predictor is established to determine the maximum raw emission value allowed to be emitted by the diesel engine; According to the engine speed, the fuel injection amount, and the emission proportionality coefficient of the diesel engine, the emission amount deviation and the fuel consumption proportionality coefficient are determined; the emission proportionality coefficient refers to a coefficient representing the proportional relationship between the actual fuel injection time of the diesel engine and the fuel injection time corresponding to the preset emission level; the emission amount deviation refers to the deviation of the emission amount between the emission value of the diesel engine and the preset level emission value; The candidate proportionality coefficient corresponding to the maximum raw emission value is determined, and the target fuel injection time and the target rail pressure are determined according to the candidate proportionality coefficient, the emission proportionality coefficient, the fuel consumption proportionality coefficient, and the candidate fuel injection time and the candidate rail pressure corresponding to the preset high, medium, and low three different levels; The ammonia-nitrogen ratio of the diesel engine is adaptively controlled according to the candidate proportionality coefficient, the emission proportionality coefficient, and the fuel consumption proportionality coefficient, and the fuel injection control of the diesel engine is performed according to the target fuel injection time and the target rail pressure; Wherein, the fuel consumption proportionality coefficient is determined by: performing a fuel consumption lookup table operation according to the engine speed and the fuel injection amount to determine the fuel consumption second-order term coefficient and the fuel consumption first-order term coefficient; establishing a cost deviation equation according to the exhaust mass flow, the exhaust molar mass, the emission amount deviation, the expected ammonia-nitrogen ratio, the calibration parameters, and the engine speed, and making the cost deviation take a preset value to determine the fuel consumption deviation between the fuel consumption value of the diesel engine and the preset level fuel consumption value; and determining the fuel consumption proportionality coefficient according to the fuel consumption deviation, the fuel consumption second-order term coefficient, and the fuel consumption first-order term coefficient; Wherein, the candidate proportionality coefficient corresponding to the maximum raw emission value is determined by: determining the corresponding compensation values for the candidate emission values of the preset high, medium, and low three different levels according to the ambient temperature lookup table, the ambient pressure lookup table, the water temperature lookup table, and the target air-fuel ratio deviation lookup table; determining the target emission values corresponding to the high, medium, and low three different levels by adding the candidate emission values of the preset high, medium, and low three different levels to the compensation values, respectively; and determining the candidate proportionality coefficient corresponding to the maximum raw emission value based on the linear interpolation method according to the relationship between the maximum raw emission value and the preset high, medium, and low three different target emission values.

2. The method of claim 1, wherein, The method for establishing the maximum nitrogen oxide raw emission allowable emission predictor to determine the maximum raw emission value allowed to be emitted by the diesel engine comprises the following steps: Data acquisition is performed by using upstream and downstream nitrogen oxide sensors, and the actual efficiency of the preset selective catalytic reduction device SCR is determined according to the acquisition results; The efficiency estimation value is determined according to the current temperature of the SCR, the current exhaust volume, and the expected ammonia-nitrogen ratio; The aftertreatment efficiency of the diesel engine is estimated according to the first-order inertial delay relationship between the efficiency estimation value and the actual efficiency; The maximum raw emission value allowed to be emitted is determined according to the aftertreatment efficiency and the downstream emission limit value.

3. The method of claim 1, wherein, The emission amount deviation is determined according to the engine speed, the fuel injection amount, and the emission proportionality coefficient of the diesel engine, which comprises the following steps: An emission lookup table operation is performed according to the engine speed and the fuel injection amount to determine the emission second-order term coefficient and the emission first-order term coefficient; According to the relationship between the actual injection time and the injection time corresponding to the preset emission level, the emission proportionality coefficient of the diesel engine is determined based on a linear interpolation method; According to the emission second-order term coefficient, the emission first-order term coefficient and the emission proportionality coefficient, the emission deviation between the diesel engine emission value and the preset level emission value is determined.

4. The method of claim 1, wherein, The target injection time and the target rail pressure are determined, including: The minimum value among the candidate proportionality coefficient, the emission proportionality coefficient and the fuel consumption proportionality coefficient is determined as the target proportionality coefficient; According to the target proportionality coefficient, and the candidate injection time and the candidate rail pressure corresponding to the preset high, medium and low three different levels, the target injection time and the target rail pressure are obtained based on a linear interpolation method.

5. The method of claim 1, wherein, The adaptive control of the ammonia nitrogen ratio of the diesel engine is performed, including: According to the exhaust air speed and the current SCR temperature, the feedforward control of the ammonia nitrogen ratio of the diesel engine is performed; According to the candidate proportionality coefficient, the emission proportionality coefficient and the fuel consumption proportionality coefficient, the weight deviation is determined, and according to the weight deviation, the feedback control of the ammonia nitrogen ratio of the diesel engine is performed.

6. A diesel engine control device characterized by comprising: including: The original emission determination module is configured to establish a maximum nitrogen oxide original emission allowance predictor according to the actual efficiency of the selective catalytic reduction device (SCR), the current SCR temperature, the current exhaust volume, the expected ammonia nitrogen ratio and the downstream emission limit value, so as to determine the maximum original emission value allowed to be emitted by the diesel engine; The coefficient determination module is configured to determine the emission deviation and the fuel consumption proportionality coefficient according to the engine speed, the fuel injection amount and the emission proportionality coefficient of the diesel engine; the emission proportionality coefficient refers to a coefficient representing the proportional relationship between the actual injection time of the diesel engine and the injection time corresponding to the preset emission level; the emission deviation refers to the deviation of the emission amount between the diesel engine emission value and the preset level emission value; The target determination module is configured to determine the candidate proportionality coefficient corresponding to the maximum original emission value, and determine the target injection time and the target rail pressure according to the candidate proportionality coefficient, the emission proportionality coefficient and the fuel consumption proportionality coefficient, and the candidate injection time and the candidate rail pressure corresponding to the preset high, medium and low three different levels; The control module is configured to perform adaptive control of the ammonia nitrogen ratio of the diesel engine according to the candidate proportionality coefficient, the emission proportionality coefficient and the fuel consumption proportionality coefficient, and perform injection control of the diesel engine according to the target injection time and the target rail pressure; The coefficient determination module is further configured to perform fuel consumption table lookup operation according to the engine speed and the fuel injection amount, so as to determine the fuel consumption second-order term coefficient and the fuel consumption first-order term coefficient; establish a cost deviation equation according to the exhaust mass flow, the exhaust molar mass, the emission deviation, the expected ammonia nitrogen ratio, the calibration parameter and the engine speed, and make the cost deviation value be a preset value, so as to determine the fuel consumption deviation between the diesel engine fuel consumption value and the preset level fuel consumption value; and determine the fuel consumption proportionality coefficient according to the fuel consumption deviation, the fuel consumption second-order term coefficient and the fuel consumption first-order term coefficient. The target determination module is specifically configured to: determine corresponding compensation values for candidate emission values of three different levels of preset high, medium and low according to an environment temperature lookup table, an environment pressure lookup table, a water temperature lookup table and according to a target air-fuel ratio deviation lookup table; determine target emission values corresponding to the three different levels of high, medium and low by taking the sum of the candidate emission values of the three different levels of preset high, medium and low and the compensation values respectively; and determine a candidate proportion coefficient corresponding to the maximum original emission value based on a linear interpolation manner according to a relationship between the maximum original emission value and the three different target emission values of preset high, medium and low.

7. An electronic device, comprising: The electronic device includes: at least one processor; and a memory connected with the at least one processor in communication; wherein The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the diesel engine control method of any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for causing the processor to execute when the computer instructions are executed to implement the diesel engine control method of any one of claims 1-5.

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