CN114790927B - Urea injection control method and device and terminal equipment - Google Patents
Urea injection control method and device and terminal equipment Download PDFInfo
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- CN114790927B CN114790927B CN202110622277.8A CN202110622277A CN114790927B CN 114790927 B CN114790927 B CN 114790927B CN 202110622277 A CN202110622277 A CN 202110622277A CN 114790927 B CN114790927 B CN 114790927B
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- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 442
- 239000004202 carbamide Substances 0.000 title claims abstract description 442
- 238000002347 injection Methods 0.000 title claims abstract description 111
- 239000007924 injection Substances 0.000 title claims abstract description 111
- 238000000034 method Methods 0.000 title claims abstract description 43
- 230000032683 aging Effects 0.000 claims abstract description 72
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 30
- 238000004590 computer program Methods 0.000 claims description 21
- 230000000694 effects Effects 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 239000007864 aqueous solution Substances 0.000 description 6
- 230000006870 function Effects 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 238000003491 array Methods 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910021642 ultra pure water Inorganic materials 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
- F01N2610/146—Control thereof, e.g. control of injectors or injection valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/18—Parameters used for exhaust control or diagnosing said parameters being related to the system for adding a substance into the exhaust
- F01N2900/1806—Properties of reducing agent or dosing system
- F01N2900/1818—Concentration of the reducing agent
Abstract
The invention is applicable to the technical field of vehicles, and discloses a urea injection control method, a urea injection control device and terminal equipment, wherein the urea injection control method comprises the following steps: acquiring the current urea demand and the current urea concentration detected by a urea concentration sensor; determining a first target compensation coefficient according to the current urea concentration and the current urea demand; acquiring a current aging degree value of a urea concentration sensor; determining a second target compensation coefficient according to the current aging degree value and the current urea demand; determining a third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient; and determining a target urea injection quantity according to the third target compensation coefficient and the current urea demand, and performing injection according to the target urea injection quantity. The invention can reduce or even avoid the influence of the aging of the urea quality (concentration) sensor on the actual urea injection quantity, ensure the real, reliable and effective urea injection quantity and lead the exhaust aftertreatment to achieve a better effect.
Description
Technical Field
The invention belongs to the technical field of vehicles, and particularly relates to a urea injection control method, a urea injection control device and terminal equipment.
Background
The exhaust gas pollutants of diesel engines mainly comprise nitrogen oxides NO x And particulate matter (Particulate Matter, PM), typically requiring the combined use of exhaust aftertreatment technology to control NO x And PM emissions. PM emissions are first reduced by an in-machine clean-up technique, and then NO is reduced by a selective catalytic reduction (SelectiveCatalyticReduction, SCR) technique x Emissions are reduced to achieve the same time as NO reduction x And PM emission purposes. The SCR exhaust aftertreatment technology is adopted, so that the engine body is changed less, the durability is good, the emission can be effectively reduced, and 2% -3% of fuel oil of the diesel engine can be saved.
The SCR system mainly comprises a catalyst, a urea supply system and a control system. The catalyst is coated on the carrier in the catalyst, so that NO can be quickened x Is used for the reduction reaction. The urea supply system provides high-pressure injection power for the urea nozzle, so that full atomization of urea liquid drops can be realized, and NO can be further improved x Is not limited, and the conversion efficiency of the catalyst is improved. The control system accurately controls the urea injection quantity in real time according to the working condition of the engine, detects the running condition of the SCR system, and can take corresponding treatment measures when the system fails.
The vehicle urea is mainly purified from industrial urea, and the main principle is as follows: 1) At 70-75 ℃, urea is hydrolyzed in aqueous solution; 2) At a temperature below 30 ℃, urea is recrystallized from the aqueous solution again; 3) The purity of the urea can be greatly improved after the hydrolysis and crystallization are finished once, and the standard requirement of the urea for vehicles can be met by generally utilizing the industrial primary urea to hydrolyze and crystallize once, wherein the output ratio is 1.5:1.
the urea for the automobile is extremely easy to be poisoned by metal ions due to the SCR catalyst carrier, so that the catalytic effect is lost, and therefore, the urea solution for the automobile must use the first-grade ultrapure water in the electronic industry. The urea quality (concentration) sensor is a sensor for measuring the urea concentration in the urea aqueous solution of the vehicle SCR system, but the urea quality (concentration) sensor can be aged gradually along with the increase of the mileage of the vehicle in the use process, and large precision deviation is easy to occur in the measurement of the urea concentration, however, the normal and efficient operation of the SCR system depends on the stability and the reliability of the urea system, the real urea concentration in the urea aqueous solution has direct influence on the emission result of the vehicle, and the aging of the urea quality (concentration) sensor easily causes the discrepancy between the urea injection quantity and the actual demand quantity, so that the exhaust aftertreatment effect is poor.
Disclosure of Invention
In view of the above, the embodiments of the present invention provide a urea injection control method, apparatus, and terminal device, so as to solve the problem that in the prior art, ageing of a urea quality (concentration) sensor easily causes that the urea injection amount is inconsistent with the actual demand amount, resulting in poor exhaust aftertreatment effect.
A first aspect of an embodiment of the present invention provides a urea injection control method, including:
acquiring the current urea demand and the current urea concentration detected by a urea concentration sensor;
determining a first target compensation coefficient according to the current urea concentration and the current urea demand;
acquiring a current aging degree value of a urea concentration sensor;
determining a second target compensation coefficient according to the current aging degree value and the current urea demand;
determining a third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient;
and determining a target urea injection quantity according to the third target compensation coefficient and the current urea demand, and performing injection according to the target urea injection quantity.
In one possible implementation, determining the first target compensation factor based on the current urea concentration and the current urea demand comprises:
and determining a first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the corresponding relation among the pre-stored urea concentration, the urea demand and the first compensation coefficient.
In one possible implementation, before determining the first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the pre-stored correspondence between the urea concentration, the urea demand and the first compensation coefficient, the method further includes:
for each urea concentration and each urea demand, obtaining a first actual urea injection quantity which enables the nitrogen oxide emission to be controlled within a preset standard range under the condition of the urea concentration and the urea demand, and dividing the first actual urea injection quantity by the urea demand to obtain a first compensation coefficient corresponding to the urea concentration and the urea demand;
the urea concentration is gradually reduced from the standard urea concentration according to a preset concentration step length until the minimum urea concentration is preset; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
In one possible implementation, determining the second target compensation factor based on the current age value and the current urea demand comprises:
and determining a second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the pre-stored corresponding relation among the aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient.
In one possible implementation, before determining the second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the correspondence between the pre-stored aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient, the method further includes:
obtaining a second actual urea injection quantity for controlling the nitrogen oxide emission within a preset standard range under the aging degree value of each urea concentration sensor and the urea demand according to the aging degree value of each urea concentration sensor and each urea demand, and dividing the second actual urea injection quantity by the urea demand to obtain a second compensation coefficient corresponding to the aging degree value of the urea concentration sensor and the urea demand;
wherein, the aging degree of the urea concentration sensor is represented by vehicle mileage; the interval of the aging degree values of the adjacent urea concentration sensors is a preset mileage interval; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
In one possible implementation, determining the third target compensation coefficient from the first target compensation coefficient and the second target compensation coefficient includes:
and multiplying the first target compensation coefficient by the second target compensation coefficient to obtain a third target compensation coefficient.
In one possible implementation, determining the target urea injection amount based on the third target compensation coefficient and the current urea demand includes:
and multiplying the third target compensation coefficient by the current urea demand to obtain the target urea injection quantity.
A second aspect of an embodiment of the present invention provides a urea injection control device, including:
the first acquisition module is used for acquiring the current urea demand and the current urea concentration detected by the urea concentration sensor;
a first coefficient determination module for determining a first target compensation coefficient based on a current urea concentration and a current urea demand;
the second acquisition module is used for acquiring the current aging degree value of the urea concentration sensor;
the second coefficient determining module is used for determining a second target compensation coefficient according to the current aging degree value and the current urea demand;
the final coefficient determining module is used for determining a third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient;
the urea injection control module is used for determining a target urea injection quantity according to the third target compensation coefficient and the current urea demand quantity and performing urea injection according to the target urea injection quantity.
A third aspect of the embodiments of the present invention provides a terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the urea injection control method according to the first aspect or any one of the possible implementations of the first aspect when the computer program is executed.
A fourth aspect of the embodiments of the present invention provides a computer readable storage medium storing a computer program which, when executed by one or more processors, implements the steps of the urea injection control method according to the first aspect or any one of the possible implementations of the first aspect.
Compared with the prior art, the embodiment of the invention has the beneficial effects that: according to the embodiment of the invention, the first target compensation coefficient is determined according to the current urea concentration and the current urea demand, the second target compensation coefficient is determined according to the current aging degree value and the current urea demand, the third target compensation coefficient is determined according to the first target compensation coefficient and the second target compensation coefficient, the target urea injection amount is determined according to the third target compensation coefficient and the current urea demand, and the urea injection is carried out according to the target urea injection amount, so that the influence of aging of a urea quality (concentration) sensor on the actual urea injection amount can be reduced or even avoided, the real, reliable and effective urea injection amount can be ensured, and the exhaust aftertreatment achieves a better effect.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of an implementation flow of a urea injection control method according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of the correspondence between urea concentration, urea demand and first compensation factor according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of the aging level value, urea demand and second compensation coefficient of a urea concentration sensor according to an embodiment of the present invention;
FIG. 4 is a schematic block diagram of a urea injection control device according to an embodiment of the present invention;
fig. 5 is a schematic block diagram of a terminal device according to an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
In order to illustrate the technical scheme of the invention, the following description is made by specific examples.
Fig. 1 is a schematic implementation flow chart of a urea injection control method according to an embodiment of the present invention, and for convenience of explanation, only a portion relevant to the embodiment of the present invention is shown. The execution body of the embodiment of the invention can be a terminal device.
As shown in fig. 1, the urea injection control method may include the following steps:
s101: the current urea demand and the current urea concentration detected by the urea concentration sensor are obtained.
In an embodiment of the present invention, the current urea demand is the current desired urea injection as determined by existing methods.
The urea concentration sensor may also be referred to as a urea quality sensor, and may detect the urea concentration.
S102: a first target compensation coefficient is determined based on the current urea concentration and the current urea demand.
In some embodiments of the present invention, the step S102 may include:
and determining a first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the corresponding relation among the pre-stored urea concentration, the urea demand and the first compensation coefficient.
In the embodiment of the invention, the corresponding relation among the urea concentration, the urea demand and the first compensation coefficient can be determined through calibration in advance, and the first compensation coefficient corresponding to the current urea concentration and the current urea demand is determined according to the corresponding relation, and is called as a first target compensation coefficient.
In some embodiments of the present invention, before determining the first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the pre-stored correspondence between the urea concentration, the urea demand and the first compensation coefficient, the method further includes:
for each urea concentration and each urea demand, obtaining a first actual urea injection quantity which enables the nitrogen oxide emission to be controlled within a preset standard range under the condition of the urea concentration and the urea demand, and dividing the first actual urea injection quantity by the urea demand to obtain a first compensation coefficient corresponding to the urea concentration and the urea demand;
the urea concentration is gradually reduced from the standard urea concentration according to a preset concentration step length until the minimum urea concentration is preset; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
In an embodiment of the present invention, the correspondence between the urea concentration, the urea demand and the first compensation coefficient may be stored in the form of a table or MAP.
Taking a table as an example, in the table, the urea demand amounts may be arranged in order from large to small, and the adjacent urea demand amounts refer to adjacent urea demand amounts in the table. The interval may be a small step size when the urea demand is in a small range and a large step size when the urea demand is in a large range.
In the table, the urea concentrations may be arranged in order from large to small, with a maximum value being the standard concentration, a minimum value being the preset minimum urea concentration, and the adjacent urea concentration intervals being the preset concentration step.
The preset concentration step length, the preset minimum urea concentration, the first preset range, the first preset step length, the second preset range and the second preset step length can be set according to actual requirements, and the specific limitation is not adopted here.
Illustratively, as shown in FIG. 3, for urea demand, the step size is 20mg/s in the range of 0-200 mg/s; within the range of 200-500 mg/s, the step length is 50mg/s. For urea concentration, the range is 32.5% -12.5% with a step size of 2%. Namely, the first preset range is 0-200 mg/s, the second preset range is 200-500 mg/s, the first preset step length is 20mg/s, the second preset step length is 50mg/s, the preset minimum urea concentration is 12.5%, and the preset concentration step length is 2%. For each urea demand and each urea concentration there is a corresponding first compensation factor. In practical applications, if there is no corresponding urea demand or no corresponding urea concentration in the table, the closest urea demand or closest urea concentration may be selected, and the corresponding first compensation coefficient may be determined.
The standard concentration of urea of the urea aqueous solution is 32.5 percent, which is mass percent, and urea with different concentrations can be blended by deionized water according to mass percent.
In an embodiment of the present invention, the process of determining the correspondence between the urea concentration, the urea demand and the first compensation coefficient may be as follows:
WLTC (Worldwide Harmonized Light Vehicles Test Cycle, global light vehicle test cycle) emissions test was first performed using standard concentration urea aqueous solution to give NO x The emission is controlled to be about 30mg/km (national six regulation limit value), the concentration of urea in the urea box is gradually regulated, the concentration is gradually reduced from 32.5% to 12.5% according to the step length of 2%, the emission test is carried out on the injection with the urea injection quantity amplified by a certain amount under each concentration, and NO is carried out x The emission amount is controlled to be about 30mg/km, and the "amplified amount" is compared with the urea demand to obtain a first compensation coefficient f1, which is filled in a value corresponding to the MAP coordinates or the table.
S103: the current aging degree value of the urea concentration sensor is obtained.
In the embodiment of the invention, the aging degree of the urea concentration sensor can be represented by the vehicle mileage, and the aging degree of the urea concentration sensor is higher as the vehicle mileage is larger.
S104: a second target compensation factor is determined based on the current age level value and the current urea demand.
In some embodiments of the present invention, the S104 may include:
and determining a second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the pre-stored corresponding relation among the aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient.
In the embodiment of the invention, the corresponding relation among the aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient can be determined through calibration in advance, and the second compensation coefficient corresponding to the current aging degree value and the current urea demand is determined according to the corresponding relation, and is called as the second target compensation coefficient.
In some embodiments of the present invention, before determining the second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the pre-stored correspondence between the aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient, the method further includes:
obtaining a second actual urea injection quantity for controlling the nitrogen oxide emission within a preset standard range under the aging degree value of each urea concentration sensor and the urea demand according to the aging degree value of each urea concentration sensor and each urea demand, and dividing the second actual urea injection quantity by the urea demand to obtain a second compensation coefficient corresponding to the aging degree value of the urea concentration sensor and the urea demand;
wherein, the aging degree of the urea concentration sensor is represented by vehicle mileage; the interval of the aging degree values of the adjacent urea concentration sensors is a preset mileage interval; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
In the embodiment of the invention, the correspondence between the aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient may be stored in the form of a table or MAP.
Taking a table as an example, in the table, the aging degree values of the urea concentration sensors may be arranged in order from small to large, and the aging degree values of the adjacent urea concentration sensors refer to the aging degree values of the adjacent urea concentration sensors in the table, and the intervals of the aging degree values of the adjacent urea concentration sensors are preset mileage intervals. The preset mileage interval can be set according to actual requirements, for example, 1 ten thousand kilometers, 2 ten thousand kilometers, and the like.
The urea demand is referred to in the foregoing description and will not be described in detail.
Illustratively, as shown in FIG. 4, for urea demand, the step size is 20mg/s in the range of 0-200 mg/s; within the range of 200-500 mg/s, the step length is 50mg/s. The range of the aging degree value of the urea concentration sensor is 0-16 ten thousand kilometers, the step length is 1 ten thousand kilometers, and the preset mileage interval is 1 ten thousand kilometers.
There is a corresponding second compensation factor for each urea demand and each urea concentration sensor aging level. In practical application, if the table has no corresponding urea demand or no corresponding aging degree value of the urea concentration sensor, the closest urea demand or the closest aging degree value of the urea concentration sensor may be selected, and the corresponding second compensation coefficient may be determined.
In the embodiment of the present invention, the process of determining the correspondence between the aging degree value of the urea concentration sensor, the urea demand amount, and the second compensation coefficient may be as follows (taking the preset mileage interval as an example of 2 kilometers):
adding standard concentration urea into a vehicle urea box, respectively selecting urea quality (concentration) sensors of ageing degrees of 2, 4 and 6 … kilometers, amplifying the urea injection quantity by a certain amount under each concentration, performing emission test, and amplifying the NO x The emission amount is controlled to be about 30mg/km, and the "amplified amount" is compared with the urea demand to obtain a compensation coefficient f2, which is filled in a table or a value corresponding to MAP coordinates.
S105: and determining a third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient.
In some embodiments of the present invention, the step S105 may include:
and multiplying the first target compensation coefficient by the second target compensation coefficient to obtain a third target compensation coefficient.
Wherein the third target compensation coefficient is the final compensation coefficient.
S106: and determining a target urea injection quantity according to the third target compensation coefficient and the current urea demand, and performing injection according to the target urea injection quantity.
In some embodiments of the present invention, the step S106 may include:
and multiplying the third target compensation coefficient by the current urea demand to obtain the target urea injection quantity.
In the embodiment of the invention, the third target compensation coefficient is multiplied by the current urea demand to obtain the target urea injection quantity, namely the corrected urea injection quantity. In the urea supply system and the control system, urea injection control is performed according to the target urea injection amount.
From the above description, it can be seen that by determining the first target compensation coefficient according to the current urea concentration and the current urea demand, determining the second target compensation coefficient according to the current aging degree value and the current urea demand, determining the third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient, determining the target urea injection amount according to the third target compensation coefficient and the current urea demand, and performing urea injection according to the target urea injection amount, the influence of aging of the urea quality (concentration) sensor on the actual urea injection amount can be reduced or even avoided, the real, reliable and effective urea injection amount can be ensured, and the exhaust aftertreatment can achieve a better effect, even if the nitrogen oxide content in the exhaust gas reaches the relevant standard requirement.
The embodiment of the invention can reduce or even avoid the influence of the urea concentration and the sensor measurement result thereof on the actual injection effective urea quantity, and can ensure the real, reliable and effective injection quantity of the urea system. The method is highly intelligent, and the compensation coefficient is calculated by accurately identifying the urea concentration and the aging degree (based on the mileage of the vehicle) of the urea quality sensor; the method has the advantages that no extra hardware cost is applied to the electric control engine, and the method is easy to popularize and low in cost; the system parameters can be flexibly configured, can be changed for urea systems of different manufacturers, and have openness and flexibility.
It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present invention.
Corresponding to the urea injection control method, an embodiment of the invention also provides a urea injection control device, which has the same beneficial effects as the urea injection control method. Fig. 4 is a schematic block diagram of a urea injection control device according to an embodiment of the present invention, and only a portion related to the embodiment of the present invention is shown for convenience of explanation.
In an embodiment of the present invention, urea injection control device 30 may include a first acquisition module 301, a first coefficient determination module 302, a second acquisition module 303, a second coefficient determination module 304, a final coefficient determination module 305, and a urea injection control module 306.
Wherein, the first acquisition module 301 is configured to acquire a current urea demand and a current urea concentration detected by a urea concentration sensor;
a first coefficient determination module 302 for determining a first target compensation coefficient based on a current urea concentration and a current urea demand;
a second obtaining module 303, configured to obtain a current aging degree value of the urea concentration sensor;
a second coefficient determination module 304 for determining a second target compensation coefficient based on the current age value and the current urea demand;
a final coefficient determining module 305, configured to determine a third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient;
the urea injection control module 306 is configured to determine a target urea injection amount according to the third target compensation coefficient and the current urea demand, and perform urea injection according to the target urea injection amount.
In one possible implementation, the first coefficient determination module 302 may also be configured to:
and determining a first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the corresponding relation among the pre-stored urea concentration, the urea demand and the first compensation coefficient.
In one possible implementation, urea injection control device 30 may also include a first calibration module.
The first calibration module is used for:
for each urea concentration and each urea demand, obtaining a first actual urea injection quantity which enables the nitrogen oxide emission to be controlled within a preset standard range under the condition of the urea concentration and the urea demand, and dividing the first actual urea injection quantity by the urea demand to obtain a first compensation coefficient corresponding to the urea concentration and the urea demand;
the urea concentration is gradually reduced from the standard urea concentration according to a preset concentration step length until the minimum urea concentration is preset; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
In one possible implementation, the second coefficient determination module 304 may also be configured to:
and determining a second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the pre-stored corresponding relation among the aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient.
In one possible implementation, urea injection control device 30 also includes a second calibration module.
The second calibration module is used for:
obtaining a second actual urea injection quantity for controlling the nitrogen oxide emission within a preset standard range under the aging degree value of each urea concentration sensor and the urea demand according to the aging degree value of each urea concentration sensor and each urea demand, and dividing the second actual urea injection quantity by the urea demand to obtain a second compensation coefficient corresponding to the aging degree value of the urea concentration sensor and the urea demand;
wherein, the aging degree of the urea concentration sensor is represented by vehicle mileage; the interval of the aging degree values of the adjacent urea concentration sensors is a preset mileage interval; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
In one possible implementation, the final coefficient determination module 305 may also be configured to:
and multiplying the first target compensation coefficient by the second target compensation coefficient to obtain a third target compensation coefficient.
In one possible implementation, urea injection control module 306 may also be configured to:
and multiplying the third target compensation coefficient by the current urea demand to obtain the target urea injection quantity.
It will be clearly understood by those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of each functional unit and module is illustrated, and in practical application, the above-mentioned functional allocation may be performed by different functional units and modules, that is, the internal structure of the urea injection control device is divided into different functional units or modules, so as to perform all or part of the above-mentioned functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above device may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
Fig. 5 is a schematic block diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 5, the terminal device 40 of this embodiment includes: one or more processors 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. The processor 401, when executing the computer program 403, implements the steps of the various urea injection control method embodiments described above, such as steps S101 to S106 shown in fig. 1. Alternatively, the processor 401, when executing the computer program 403, performs the functions of the modules/units of the urea injection control device embodiments described above, such as the functions of the modules 301 to 306 shown in fig. 4.
Illustratively, the computer program 403 may be partitioned into one or more modules/units that are stored in the memory 402 and executed by the processor 401 to complete the present application. The one or more modules/units may be a series of computer program instruction segments capable of performing the specified functions describing the execution of the computer program 403 in the terminal device 40. For example, the computer program 403 may be divided into a first acquisition module, a first coefficient determination module, a second acquisition module, a second coefficient determination module, a final coefficient determination module, and a urea injection control module, each of which functions specifically as follows:
the first acquisition module is used for acquiring the current urea demand and the current urea concentration detected by the urea concentration sensor;
a first coefficient determination module for determining a first target compensation coefficient based on a current urea concentration and a current urea demand;
the second acquisition module is used for acquiring the current aging degree value of the urea concentration sensor;
the second coefficient determining module is used for determining a second target compensation coefficient according to the current aging degree value and the current urea demand;
the final coefficient determining module is used for determining a third target compensation coefficient according to the first target compensation coefficient and the second target compensation coefficient;
the urea injection control module is used for determining a target urea injection quantity according to the third target compensation coefficient and the current urea demand quantity and performing urea injection according to the target urea injection quantity.
Other modules or units may be described with reference to the embodiment shown in fig. 4, and will not be described here again.
The terminal device 40 may be an in-vehicle control terminal. The terminal device 40 includes, but is not limited to, a processor 401, a memory 402. It will be appreciated by those skilled in the art that fig. 5 is merely an example of the terminal device 40 and is not meant to be limiting of the terminal device 40, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., the terminal device 40 may also include input devices, output devices, network access devices, buses, etc.
The processor 401 may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 402 may be an internal storage unit of the terminal device 40, such as a hard disk or a memory of the terminal device 40. The memory 402 may also be an external storage device of the terminal device 40, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the terminal device 40. Further, the memory 402 may also include both internal storage units and external storage devices of the terminal device 40. The memory 402 is used for storing the computer program 403 and other programs and data required by the terminal device 40. The memory 402 may also be used to temporarily store data that has been output or is to be output.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed urea injection control device and method may be implemented in other manners. For example, the urea injection control device embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical functional division, and there may be additional divisions in actual implementation, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated modules/units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present application may implement all or part of the flow of the method of the above embodiment, or may be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the computer program may implement the steps of each method embodiment described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth. It should be noted that the computer readable medium may include content that is subject to appropriate increases and decreases as required by jurisdictions in which such content is subject to legislation and patent practice, such as in certain jurisdictions in which such content is not included as electrical carrier signals and telecommunication signals.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (6)
1. A urea injection control method, characterized by comprising:
acquiring the current urea demand and the current urea concentration detected by a urea concentration sensor;
determining a first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the corresponding relation among the pre-stored urea concentration, the urea demand and the first compensation coefficient;
acquiring a current aging degree value of the urea concentration sensor;
determining a second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the corresponding relation among the pre-stored aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient;
multiplying the first target compensation coefficient and the second target compensation coefficient to obtain a third target compensation coefficient;
multiplying the third target compensation coefficient by the current urea demand to obtain a target urea injection quantity, and performing urea injection according to the target urea injection quantity.
2. The urea injection control method according to claim 1, characterized by further comprising, before the determining the first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the correspondence between the pre-stored urea concentration, the urea demand, and the first compensation coefficient:
for each urea concentration and each urea demand, obtaining a first actual urea injection quantity which enables the nitrogen oxide emission to be controlled within a preset standard range under the condition of the urea concentration and the urea demand, and dividing the first actual urea injection quantity by the urea demand to obtain a first compensation coefficient corresponding to the urea concentration and the urea demand;
the urea concentration is gradually reduced from the standard urea concentration according to a preset concentration step length until the minimum urea concentration is preset; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
3. The urea injection control method according to claim 1, characterized by further comprising, before the determining the second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the correspondence between the pre-stored aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient:
obtaining a second actual urea injection quantity for controlling the nitrogen oxide emission within a preset standard range under the aging degree value of each urea concentration sensor and the urea demand according to the aging degree value of each urea concentration sensor and each urea demand, and dividing the second actual urea injection quantity by the urea demand to obtain a second compensation coefficient corresponding to the aging degree value of the urea concentration sensor and the urea demand;
wherein, the aging degree of the urea concentration sensor is represented by vehicle mileage; the interval of the aging degree values of the adjacent urea concentration sensors is a preset mileage interval; when the urea demand is in a first preset range, the interval between adjacent urea demands is a first preset step length, when the urea demand is in a second preset range, the interval between adjacent urea demands is a second preset step length, the first preset step length is smaller than the second preset step length, and the minimum value of the second preset range is larger than the maximum value of the first preset range.
4. A urea injection control device, characterized by comprising:
the first acquisition module is used for acquiring the current urea demand and the current urea concentration detected by the urea concentration sensor;
the first coefficient determining module is used for determining a first target compensation coefficient corresponding to the current urea concentration and the current urea demand according to the corresponding relation among the pre-stored urea concentration, the urea demand and the first compensation coefficient;
the second acquisition module is used for acquiring the current aging degree value of the urea concentration sensor;
the second coefficient determining module is used for determining a second target compensation coefficient corresponding to the current aging degree value and the current urea demand according to the corresponding relation among the pre-stored aging degree value of the urea concentration sensor, the urea demand and the second compensation coefficient;
the final coefficient determining module is used for multiplying the first target compensation coefficient and the second target compensation coefficient to obtain a third target compensation coefficient;
and the urea injection control module is used for multiplying the third target compensation coefficient by the current urea demand to obtain a target urea injection quantity, and performing urea injection according to the target urea injection quantity.
5. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the urea injection control method according to any one of claims 1 to 3 when executing the computer program.
6. A computer readable storage medium, characterized in that it stores a computer program which, when executed by one or more processors, implements the steps of the urea injection control method according to any one of claims 1 to 3.
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| JP2019073980A (en) * | 2017-10-12 | 2019-05-16 | いすゞ自動車株式会社 | Exhaust emission control device for internal combustion engine |
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| US8074445B2 (en) * | 2008-04-30 | 2011-12-13 | Cummins Ip, Inc. | Apparatus, system, and method for reducing NOx emissions on an SCR catalyst |
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| JP2019073980A (en) * | 2017-10-12 | 2019-05-16 | いすゞ自動車株式会社 | Exhaust emission control device for internal combustion engine |
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