CN117685081A - Urea injection control method and device, storage medium and electronic equipment - Google Patents
Urea injection control method and device, storage medium and electronic equipment Download PDFInfo
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- CN117685081A CN117685081A CN202410030094.0A CN202410030094A CN117685081A CN 117685081 A CN117685081 A CN 117685081A CN 202410030094 A CN202410030094 A CN 202410030094A CN 117685081 A CN117685081 A CN 117685081A
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- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 155
- 239000004202 carbamide Substances 0.000 title claims abstract description 155
- 238000002347 injection Methods 0.000 title claims abstract description 87
- 239000007924 injection Substances 0.000 title claims abstract description 87
- 238000000034 method Methods 0.000 title claims abstract description 46
- 238000012545 processing Methods 0.000 claims abstract description 10
- 239000000446 fuel Substances 0.000 claims description 19
- 230000008569 process Effects 0.000 abstract description 11
- 238000002425 crystallisation Methods 0.000 description 7
- 230000008025 crystallization Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 238000010531 catalytic reduction reaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001595 flow curve Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
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Abstract
The invention provides a urea injection control method and device, a storage medium and electronic equipment, wherein an ideal value of exhaust flow is determined by using the air inlet flow detected by an air pressure sensor of a vehicle; when the exhaust flow of the differential pressure sensor of the vehicle reaches an ideal exhaust flow value, determining a target time and an exhaust lag time; the target time is when the exhaust flow of the differential pressure sensor reaches an ideal exhaust flow value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the time period required for the exhaust flow rate of the differential pressure sensor to reach the ideal exhaust flow rate value; and determining the exhaust flow rate by using the exhaust lag time, and processing the lag time determined according to the exhaust flow rate and the target time to obtain urea injection time, and controlling urea injection according to the urea injection time. The whole process considers the time delay of the exhaust gas from the differential pressure sensor to the urea nozzle, avoids the influence of the time delay on urea injection, improves the accuracy of urea injection timing, ensures that the urea is fully translated with the exhaust gas, and reduces the emission of harmful gas.
Description
Technical Field
The present invention relates to the field of tail gas treatment technologies, and in particular, to a urea injection control method and apparatus, a storage medium, and an electronic device.
Background
At present, in vehicles applying non-road national four standards, an SCR route is generally adopted to reduce NOx emission, a downstream NOx sensor is arranged to monitor tail emission, a urea nozzle is an important component of SCR, and the injection effect of the urea nozzle directly influences NOx conversion efficiency.
The vehicle applying the non-road national four standards often shows stronger transient characteristics in the non-road operation, and the transient is mainly reflected in the rapid increase and decrease of the exhaust flow along with the load change, so that the urea injection time cannot be accurately coupled with the exhaust flow, the mixing effect of urea and exhaust is poor, and the risks of crystallization and exceeding of NOx emission are caused.
Disclosure of Invention
In view of the above, the embodiment of the invention provides a urea injection control method and device, a storage medium and an electronic device.
In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:
a urea injection control method comprising:
acquiring air inlet flow detected by an air pressure sensor of a vehicle, and determining an ideal exhaust flow value corresponding to the air inlet flow;
when the exhaust flow rate of the differential pressure sensor of the vehicle reaches the ideal value of the exhaust flow rate, determining a target time and an exhaust lag time; the target time is when the exhaust flow rate of the differential pressure sensor reaches the ideal exhaust flow rate value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the differential pressure sensor when the exhaust flow rate reaches the ideal exhaust flow rate value;
determining an exhaust flow rate of the vehicle using the exhaust lag time;
determining a delay period of exhaust gas of the vehicle from the differential pressure sensor to a urea nozzle of the vehicle using the exhaust gas flow rate;
and determining urea injection time based on the delay time and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time.
In the above method, optionally, the determining an ideal value of the exhaust flow corresponding to the intake flow includes:
determining a fuel flow rate of the vehicle;
and processing the air inlet flow and the fuel flow to obtain an ideal exhaust flow value corresponding to the air inlet flow.
The method, optionally, the determining process of the exhaust flow of the differential pressure sensor of the vehicle includes:
acquiring an engine speed of the vehicle;
acquiring a differential pressure value of the differential pressure sensor;
and determining the exhaust flow of the differential pressure sensor of the vehicle in a preset exhaust flow meter by using the engine speed and the differential pressure value.
The method, optionally, wherein the determining the exhaust flow rate of the vehicle by using the exhaust lag time length includes:
determining a first distance between the air pressure sensor and the differential pressure sensor;
and calculating the exhaust lag time and the first distance to obtain the exhaust flow rate of the vehicle.
The method, optionally, wherein the determining the delay time of the exhaust gas of the vehicle from the differential pressure sensor to the urea nozzle of the vehicle by using the exhaust gas flow rate includes:
determining a second distance between the differential pressure sensor and the urea nozzle;
and calculating the exhaust flow rate and the second distance to obtain the delay time of the exhaust of the vehicle from the differential pressure sensor to the urea nozzle of the vehicle.
The method, optionally, the determining the urea injection time based on the delay time length and the target time includes:
and carrying out addition operation on the delay time length and the target time to obtain urea injection time.
A urea injection control device comprising:
a first acquisition unit configured to acquire an intake air flow rate detected by an air pressure sensor of a vehicle, and determine an exhaust gas flow rate ideal value corresponding to the intake air flow rate;
a first determination unit configured to determine a target time and an exhaust lag time period when an exhaust flow rate of a differential pressure sensor of the vehicle reaches the exhaust flow rate ideal value; the target time is when the exhaust flow rate of the differential pressure sensor reaches the ideal exhaust flow rate value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the differential pressure sensor when the exhaust flow rate reaches the ideal exhaust flow rate value;
a second determination unit configured to determine an exhaust flow rate of the vehicle using the exhaust lag time period;
a third determination unit for determining a delay period of exhaust gas of the vehicle from the differential pressure sensor to a urea nozzle of the vehicle using the exhaust gas flow rate;
and the control unit is used for determining urea injection time based on the delay time and the target time and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time.
The above apparatus, optionally, the first obtaining unit includes:
a first determination subunit configured to determine a fuel flow rate of the vehicle;
and the processing subunit is used for processing the air inlet flow and the fuel flow to obtain an ideal exhaust flow value corresponding to the air inlet flow.
The above device, optionally, further comprises:
a second acquisition unit configured to acquire an engine speed of the vehicle;
a third acquisition unit configured to acquire a differential pressure value of the differential pressure sensor;
and a fourth determining unit configured to determine an exhaust flow rate of a differential pressure sensor of the vehicle in a preset exhaust flow rate meter, using the engine speed and the differential pressure value.
The above apparatus, optionally, the second determining unit includes:
a second determining subunit configured to determine a first distance between the air pressure sensor and the differential pressure sensor;
and the first operation subunit is used for calculating the exhaust lag time and the first distance to obtain the exhaust flow rate of the vehicle.
In another embodiment provided by the present invention, the third determining unit of the apparatus includes:
a third determination subunit for determining a second distance between the differential pressure sensor and the urea nozzle;
and the second operation subunit is used for calculating the exhaust flow rate and the second distance to obtain the delay time of the exhaust of the vehicle from the differential pressure sensor to the urea nozzle of the vehicle.
The above device, optionally, the control unit includes:
and the third operation subunit is used for carrying out addition operation on the delay time and the target time to obtain urea injection time.
A storage medium comprising stored instructions, wherein the instructions, when executed, control a device in which the storage medium resides to perform a urea injection control method as described above.
An electronic device comprising a memory, and one or more instructions, wherein the one or more instructions are stored in the memory and configured to be executed by one or more processors to perform a urea injection control method as described above.
Compared with the prior art, the invention has the following advantages:
in the method provided by the invention, the air inlet flow detected by the air pressure sensor of the vehicle is obtained, and an ideal value of the exhaust flow corresponding to the air inlet flow is determined; when the exhaust flow of the differential pressure sensor of the vehicle reaches an ideal exhaust flow value, determining a target time and an exhaust lag time; the target time is when the exhaust flow of the differential pressure sensor reaches an ideal exhaust flow value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the time period required for the exhaust flow rate of the differential pressure sensor to reach the ideal exhaust flow rate value; determining an exhaust flow rate of the vehicle using the exhaust lag time; determining a delay period of exhaust gas of a vehicle from a differential pressure sensor to a urea nozzle of the vehicle using an exhaust gas flow rate; and determining urea injection time based on the delay time and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time. When urea is injected, the measured values of the air pressure sensor and the pressure difference sensor are used for determining the flow rate of exhaust gas, then the flow rate of exhaust gas is used for determining the time delay time required by the exhaust gas from the pressure difference sensor to the urea nozzle, the urea injection time is determined according to the time delay time, the time delay from the pressure difference sensor to the urea nozzle is considered when urea is injected, the influence of the time delay on urea injection is avoided, the timing of urea injection is more accurate, and the problems of crystallization or poor emission adaptability caused by uneven gas mixing due to poor urea injection timing are reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for controlling urea injection according to an embodiment of the present invention;
FIG. 2 is a flow chart of determining exhaust flow by a differential pressure sensor of a vehicle according to an embodiment of the present invention;
FIG. 3 is an exemplary diagram for determining urea injection time provided by an embodiment of the present invention;
FIG. 4 is an exemplary diagram of determining exhaust flow provided by an embodiment of the present invention;
FIG. 5 is a schematic diagram of a urea injection control device according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Term interpretation:
urea nozzle: selective Catalytic Reduction an important component of an SCR selective catalytic reduction system, which can atomize and inject pressurized urea.
A mixer: an area where atomized urea and engine exhaust mix during the aftertreatment.
Exhaust flow rate: the flow rate of exhaust gas produced by engine combustion is generally assessed as either mass flow rate or volumetric flow rate.
According to the background technology, the existing urea injection mode has the defects that the urea injection time cannot be accurately coupled with the exhaust flow, the mixing effect of urea and exhaust is poor, and crystallization and exceeding of NOx emission occur. In the prior art, the exhaust flow and the change of the exhaust flow are an idealized model, urea delay injection is performed on the basis of the idealized model, and the problem of poor coupling degree of injection timing can be solved to a certain extent, but the defect of open loop control exists, and the injection timing also has uncertainty when the change speed of the exhaust gas is uncertain.
In order to solve the problem of inaccurate urea injection timing in the prior art, the invention provides a urea injection control scheme, which is used for judging the gas flow rate according to the time delay of the measured values of the air pressure sensor and the pressure difference sensor, determining the time delay from the pressure difference sensor to urea injection of exhaust according to the gas flow rate, determining the urea injection time according to the time delay, and eliminating the influence of the time delay of the exhaust process by a small amount in the whole process, so that the urea injection timing is more accurate, and the problems of uneven gas mixing caused by the poor urea injection timing and poor crystallization or emission adaptability are effectively reduced.
The invention is operational with numerous general purpose or special purpose computing device environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet devices, multiprocessor devices, distributed computing environments that include any of the above devices or devices, and the like.
The present invention may be applied to a control system of a vehicle, which may be composed of a computing device, or a computer terminal.
Referring to fig. 1, a method flowchart of a urea injection control method according to an embodiment of the present invention is specifically described below.
S101, acquiring air inlet flow detected by an air pressure sensor of the vehicle, and determining an ideal exhaust flow value corresponding to the air inlet flow.
When the vehicle is in a working state, the air inlet flow detected by an air pressure sensor of the vehicle is obtained, the air pressure sensor is a BPS sensor in the vehicle, the BPS sensor is used for measuring the air inlet flow of the vehicle, and the measured air inlet flow can be the air flow which enters the vehicle and is used for burning fuel.
When the vehicle is in a working state, an air pressure sensor of the vehicle detects the air inlet flow in real time, and after the air inlet flow is detected, an ideal value of the exhaust flow corresponding to the air inlet flow can be determined.
When determining the ideal exhaust flow rate, it is also necessary to determine the fuel flow rate of the vehicle detected when detecting the intake flow rate, and process the intake flow rate and the fuel flow rate to obtain the ideal exhaust flow rate corresponding to the intake flow rate. The exhaust gas flow rate ideal value may also be referred to as an exhaust gas flow rate theoretical value, which is the flow rate of exhaust gas theoretically discharged after combustion of the intake air flow rate and the fuel flow rate.
The fuel flow of the vehicle is controlled by the ECU of the vehicle, and the intake air flow and the gas flow of the vehicle are obtained at the same time, and then the intake air flow and the gas flow are processed to obtain the exhaust gas flow ideal value of the exhaust gas of the vehicle.
The intake flow and the exhaust flow keep a certain conversion rule, and an ideal value of the exhaust flow can be determined according to the conversion rule, and the process of determining the ideal value of the exhaust flow is as follows: exhaust flow = intake flow/3.6 +840 fuel flow/3600, the exhaust flow in this equation is the exhaust flow ideal value.
S102, when the exhaust flow of the differential pressure sensor of the vehicle reaches an ideal exhaust flow value, determining target time and exhaust lag time; the target time is when the exhaust flow of the differential pressure sensor reaches an ideal exhaust flow value; the exhaust lag time is the time required for the exhaust flow rate to reach the desired value of the exhaust flow rate from the determination of the desired value of the exhaust flow rate to the differential pressure sensor.
When the vehicle is in a working state, the differential pressure sensor of the vehicle can determine the exhaust flow in real time, and the determined exhaust flow is the flow of the exhaust gas actually discharged in the vehicle; the flow rate of the exhaust gas actually discharged from the vehicle should be identical to the flow rate of the exhaust gas theoretically discharged. A certain time is required for fuel combustion, a certain distance is reserved between a pressure difference sensor and a pressure sensor of a vehicle, and a certain time is also required for exhaust gas to flow from the pressure sensor to the pressure difference sensor, so that from the fact that an ideal value of the discharge flow is determined based on the air inlet flow detected by the pressure sensor, to the fact that the pressure difference sensor detects the discharge flow corresponding to the air inlet flow, hysteresis exists, and the hysteresis time can be regarded as exhaust hysteresis duration; in other words, the exhaust gas retard period may also be a period from determination of the ideal exhaust gas flow rate value to the time required for the exhaust gas flow rate of the differential pressure sensor to reach the ideal exhaust gas flow rate value.
The present invention needs to determine the exhaust gas retard period and the time at which the exhaust gas flow rate of the differential pressure sensor reaches the exhaust gas flow rate ideal value as the target time in order to subsequently determine the flow rate of the exhaust gas in the vehicle.
The differential pressure changes generated by the differential pressure sensor at the differential pressure sensor are different for different exhaust flows, and the process of determining the exhaust flow by the differential pressure sensor of the vehicle is described in detail below with reference to fig. 2.
S201, acquiring the engine speed of the vehicle.
An operating parameter of the vehicle is obtained, and an engine speed is determined from the operating parameter.
S202, acquiring a differential pressure value of the differential pressure sensor.
S203, determining the exhaust flow of the differential pressure sensor of the vehicle in a preset exhaust flow meter by using the engine speed and the differential pressure value.
The exhaust flow meter is a preset meter, different engine speeds and different exhaust flows corresponding to the differential pressure values in the meter, and further, the relationship of differential pressure changes generated by the differential pressure sensors of the different exhaust flows is reflected in the meter.
S103, determining the exhaust flow rate of the vehicle by using the exhaust lag time.
The distance between the air pressure sensor and the pressure difference sensor in the vehicle is a certain distance, the distance between the air pressure sensor and the pressure difference sensor can be determined by acquiring parameters of the vehicle, the distance between the air pressure sensor and the pressure difference sensor is a first distance, and the exhaust flow rate of the exhaust gas of the vehicle can be obtained by dividing the first distance and the exhaust lag time.
S104, determining the delay time of the exhaust gas of the vehicle from the differential pressure sensor to the urea nozzle of the vehicle by using the exhaust gas flow rate.
Further, a certain distance exists between the pressure difference sensor of the vehicle and the urea nozzle of the vehicle, the distance between the pressure difference sensor and the urea nozzle is a second distance, a certain time is needed for the exhaust gas to flow from the pressure difference sensor to the urea nozzle, the time for the exhaust gas to flow from the pressure difference sensor to the urea nozzle is needed to be determined, the time can be regarded as delay time, and the delay time can be obtained by multiplying the exhaust gas flow rate by the second distance.
The exhaust gas of the vehicle refers to the gas discharged from the vehicle, and may be regarded as exhaust gas.
S105, determining urea injection time based on the delay time and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time.
The target time is the time when the exhaust flow detected by the differential pressure sensor reaches an ideal exhaust flow value; after the delay time is determined, adding the delay time and the target time to obtain urea injection time, wherein the urea injection time is the best time for injecting urea, and when the time of the vehicle reaches the urea injection time, the urea injection nozzle is controlled to inject urea, so that the urea injection precision is improved.
In the method provided by the embodiment of the invention, the air inlet flow detected by the air pressure sensor of the vehicle is obtained, and the ideal value of the exhaust flow corresponding to the air inlet flow is determined; when the exhaust flow of the differential pressure sensor of the vehicle reaches an ideal exhaust flow value, determining a target time and an exhaust lag time; the target time is when the exhaust flow of the differential pressure sensor reaches an ideal exhaust flow value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the time period required for the exhaust flow rate of the differential pressure sensor to reach the ideal exhaust flow rate value; determining an exhaust flow rate of the vehicle using the exhaust lag time; determining a delay period of exhaust gas of a vehicle from a differential pressure sensor to a urea nozzle of the vehicle using an exhaust gas flow rate; and determining urea injection time based on the delay time and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time. When urea is injected, the measured values of the air pressure sensor and the pressure difference sensor are used for determining the flow rate of exhaust gas, then the flow rate of exhaust gas is used for determining the time delay time required by the exhaust gas from the pressure difference sensor to the urea nozzle, the urea injection time is determined according to the time delay time, the time delay from the pressure difference sensor to the urea nozzle is considered when urea is injected, the influence of the time delay on urea injection is avoided, the timing of urea injection is more accurate, and the problems of crystallization or poor emission adaptability caused by uneven gas mixing due to poor urea injection timing are reduced.
In the scheme provided by the invention, the gas flow rate is judged according to the time delay of the measured values of the BPS sensor and the DPF differential pressure sensor, the distance from the differential pressure sensor to the urea nozzle is fixed, and the time can be calculated. The DPF differential pressure sensor records the time when the exhaust gas reaches the differential pressure sensor, and the time when the exhaust gas reaches the nozzle is added on the basis, so that the optimal injection time of the urea is obtained.
Referring to fig. 3, an exemplary diagram for determining urea injection time according to an embodiment of the present invention is shown, where a gas flow delay (corresponding to the exhaust lag time above) is determined based on a BPS sensor and a differential pressure sensor, curve 1 in the diagram represents a variation curve of an intake air flow through the BPS sensor, curve 2 represents a variation curve of an exhaust gas flow through the differential pressure sensor, and curve 3 represents a urea injection curve.
During the combustion process of fuel, the inlet air flow and the exhaust air flow keep certain conversion rules, namely: exhaust flow = intake flow/3.6 +840 fuel flow/3600, whereby a model value of exhaust flow is calculated. Further, the model is significant in that when the gas transient changes, both the intake and exhaust are plotted like a sinusoidal function, and it is difficult to identify whether the value reaching the differential pressure sensor is a peak. Thus, the gas variation will produce an ideal value (MAP) of the pressure difference variation at the pressure difference sensor, and when the actual variation approaches this preset value, a time difference between sinusoidal waveforms representing the two gas flows is found.
The pressure difference changes generated by different exhaust flows at the pressure difference sensor are different, the corresponding relation is written in a preset map (corresponding to the exhaust flow meter above), and the exhaust flow measured by the pressure difference sensor can be obtained by inquiring the map through the engine speed and the pressure difference value. During actual operation, the sensor measured exhaust flow and the theoretical exhaust flow keep a lag behind, which is Δt (equivalent to the exhaust lag time above).
Referring to FIG. 4, an exemplary graph of determining exhaust flow is provided, wherein curve a is a theoretical exhaust flow curve; curve b is the curve of the exhaust flow differential pressure sensor side value and is also the curve of the exhaust flow of the differential pressure sensor; curve c is the curve of the intake air flow rate. As shown in the figure, the line shape of the theoretical discharge flow rate (i.e., the theoretical value of the discharge flow rate) and the line shape of the actual discharge flow rate (the discharge flow rate of the differential pressure sensor) are highly uniform, and the time difference of the other line shape can be monitored after the data synchronization is completed. As can be seen from fig. 4, there is a lag between the theoretical exhaust flow rate value and the exhaust flow rate of the differential pressure sensor, and the lag time is Δt.
Continuing with the description of FIG. 3, after the lag time Deltat is determined, the distance between the BPS sensor and the differential pressure sensor can be divided by the lag time to obtain the exhaust flow rate, then the distance between the differential pressure sensor and the urea nozzle is multiplied by the exhaust flow rate to determine the duration from the differential pressure sensor to the urea nozzle, and then the time when the exhaust gas reaches the differential pressure sensor is added with the duration from the differential pressure sensor to the urea spraying, so that the optimal time for spraying urea, namely the time when the gas reaches the SCR, can be obtained.
By adopting the scheme provided by the invention to control urea injection, urea can be injected when the exhaust gas reaches the SCR, so that the urea is fully reflected with the exhaust gas, thereby reducing the emission of NOx in the exhaust gas and reducing pollution.
The invention uses the following time delay to judge the time difference, and uses the original vehicle sensor to complete the gas flow rate calculation, and calculates the urea injection time based on the time difference, so the urea injection is more accurate. The problem of crystallization or poor emission adaptability caused by uneven gas mixing due to poor urea injection timing can be reduced to a certain extent.
Corresponding to the method shown in fig. 1, the present invention also provides a urea injection control device for supporting the implementation of the method shown in fig. 1, which may be provided in a control system of a vehicle.
Referring to fig. 5, a schematic structural diagram of a urea injection control device according to an embodiment of the present invention is described below.
A first obtaining unit 501 configured to obtain an intake air flow rate detected by an air pressure sensor of a vehicle, and determine an exhaust gas flow rate ideal value corresponding to the intake air flow rate;
a first determining unit 502 for determining a target time and an exhaust lag time period when an exhaust flow rate of a differential pressure sensor of the vehicle reaches the exhaust flow rate ideal value; the target time is when the exhaust flow rate of the differential pressure sensor reaches the ideal exhaust flow rate value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the differential pressure sensor when the exhaust flow rate reaches the ideal exhaust flow rate value;
a second determination unit 503 for determining an exhaust flow rate of the vehicle using the exhaust lag time period;
a third determining unit 504 for determining a delay period of exhaust gas of the vehicle from the differential pressure sensor to a urea nozzle of the vehicle using the exhaust gas flow rate;
a control unit 505 for determining a urea injection time based on the delay period and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time.
In the device provided by the embodiment of the invention, the air inlet flow detected by the air pressure sensor of the vehicle is obtained, and the ideal value of the exhaust flow corresponding to the air inlet flow is determined; when the exhaust flow of the differential pressure sensor of the vehicle reaches an ideal exhaust flow value, determining a target time and an exhaust lag time; the target time is when the exhaust flow of the differential pressure sensor reaches an ideal exhaust flow value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the time period required for the exhaust flow rate of the differential pressure sensor to reach the ideal exhaust flow rate value; determining an exhaust flow rate of the vehicle using the exhaust lag time; determining a delay period of exhaust gas of a vehicle from a differential pressure sensor to a urea nozzle of the vehicle using an exhaust gas flow rate; and determining urea injection time based on the delay time and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time. When urea is injected, the measured values of the air pressure sensor and the pressure difference sensor are used for determining the flow rate of exhaust gas, then the flow rate of exhaust gas is used for determining the time delay time required by the exhaust gas from the pressure difference sensor to the urea nozzle, the urea injection time is determined according to the time delay time, the time delay from the pressure difference sensor to the urea nozzle is considered when urea is injected, the influence of the time delay on urea injection is avoided, the timing of urea injection is more accurate, and the problems of crystallization or poor emission adaptability caused by uneven gas mixing due to poor urea injection timing are reduced.
In another embodiment provided by the present invention, the first obtaining unit 501 of the apparatus includes:
a first determination subunit configured to determine a fuel flow rate of the vehicle;
and the processing subunit is used for processing the air inlet flow and the fuel flow to obtain an ideal exhaust flow value corresponding to the air inlet flow.
In another embodiment provided by the present invention, the apparatus further comprises:
a second acquisition unit configured to acquire an engine speed of the vehicle;
a third acquisition unit configured to acquire a differential pressure value of the differential pressure sensor;
and a fourth determining unit configured to determine an exhaust flow rate of a differential pressure sensor of the vehicle in a preset exhaust flow rate meter, using the engine speed and the differential pressure value.
In another embodiment provided by the present invention, the second determining unit 503 of the apparatus includes:
a second determining subunit configured to determine a first distance between the air pressure sensor and the differential pressure sensor;
and the first operation subunit is used for calculating the exhaust lag time and the first distance to obtain the exhaust flow rate of the vehicle.
In another embodiment provided by the present invention, the third determining unit 504 of the apparatus includes:
a third determination subunit for determining a second distance between the differential pressure sensor and the urea nozzle;
and the second operation subunit is used for calculating the exhaust flow rate and the second distance to obtain the delay time of the exhaust of the vehicle from the differential pressure sensor to the urea nozzle of the vehicle.
In another embodiment provided by the present invention, the control unit 505 of the apparatus includes:
and the third operation subunit is used for carrying out addition operation on the delay time and the target time to obtain urea injection time.
The embodiment of the invention also provides a storage medium, which comprises stored instructions, wherein the equipment where the storage medium is located is controlled to execute the urea injection control method when the instructions run.
The embodiment of the invention also provides an electronic device, the structure of which is shown in fig. 6, specifically including a memory 601, and one or more instructions 602, where the one or more instructions 602 are stored in the memory 601, and configured to be executed by the one or more processors 603 to execute the urea injection control method described above by the one or more instructions 602.
It should be noted that, information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, presented data, etc.) related to the present application are information and data authorized by the user or sufficiently authorized by each party, and the collection, use, and processing of related data are required to comply with related laws and regulations and standards of related countries and regions.
The specific implementation process and derivative manner of the above embodiments are all within the protection scope of the present invention.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a system or system embodiment, since it is substantially similar to a method embodiment, the description is relatively simple, with reference to the description of the method embodiment being made in part. The systems and system embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative elements and steps are described above generally in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. 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 invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A urea injection control method, characterized by comprising:
acquiring air inlet flow detected by an air pressure sensor of a vehicle, and determining an ideal exhaust flow value corresponding to the air inlet flow;
when the exhaust flow rate of the differential pressure sensor of the vehicle reaches the ideal value of the exhaust flow rate, determining a target time and an exhaust lag time; the target time is when the exhaust flow rate of the differential pressure sensor reaches the ideal exhaust flow rate value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the differential pressure sensor when the exhaust flow rate reaches the ideal exhaust flow rate value;
determining an exhaust flow rate of the vehicle using the exhaust lag time;
determining a delay period of exhaust gas of the vehicle from the differential pressure sensor to a urea nozzle of the vehicle using the exhaust gas flow rate;
and determining urea injection time based on the delay time and the target time, and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time.
2. The method of claim 1, wherein the determining an exhaust flow ideal value corresponding to the intake flow comprises:
determining a fuel flow rate of the vehicle;
and processing the air inlet flow and the fuel flow to obtain an ideal exhaust flow value corresponding to the air inlet flow.
3. The method of claim 1, wherein the determining of the exhaust flow of the differential pressure sensor of the vehicle comprises:
acquiring an engine speed of the vehicle;
acquiring a differential pressure value of the differential pressure sensor;
and determining the exhaust flow of the differential pressure sensor of the vehicle in a preset exhaust flow meter by using the engine speed and the differential pressure value.
4. The method of claim 1, wherein the determining an exhaust flow rate of the vehicle using the exhaust lag time period comprises:
determining a first distance between the air pressure sensor and the differential pressure sensor;
and calculating the exhaust lag time and the first distance to obtain the exhaust flow rate of the vehicle.
5. The method of claim 1, wherein the applying the exhaust gas flow rate to determine a delay period of exhaust gas of the vehicle from the differential pressure sensor to a urea nozzle of the vehicle comprises:
determining a second distance between the differential pressure sensor and the urea nozzle;
and calculating the exhaust flow rate and the second distance to obtain the delay time of the exhaust of the vehicle from the differential pressure sensor to the urea nozzle of the vehicle.
6. The method of claim 1, wherein the determining a urea injection time based on the delay period and the target time comprises:
and carrying out addition operation on the delay time length and the target time to obtain urea injection time.
7. A urea injection control device, characterized by comprising:
a first acquisition unit configured to acquire an intake air flow rate detected by an air pressure sensor of a vehicle, and determine an exhaust gas flow rate ideal value corresponding to the intake air flow rate;
a first determination unit configured to determine a target time and an exhaust lag time period when an exhaust flow rate of a differential pressure sensor of the vehicle reaches the exhaust flow rate ideal value; the target time is when the exhaust flow rate of the differential pressure sensor reaches the ideal exhaust flow rate value; the exhaust lag time is a time period from determining the ideal exhaust flow rate value to the differential pressure sensor when the exhaust flow rate reaches the ideal exhaust flow rate value;
a second determination unit configured to determine an exhaust flow rate of the vehicle using the exhaust lag time period;
a third determination unit for determining a delay period of exhaust gas of the vehicle from the differential pressure sensor to a urea nozzle of the vehicle using the exhaust gas flow rate;
and the control unit is used for determining urea injection time based on the delay time and the target time and controlling a urea nozzle of the vehicle to inject urea according to the urea injection time.
8. The apparatus of claim 7, wherein the first acquisition unit comprises:
a first determination subunit configured to determine a fuel flow rate of the vehicle;
and the processing subunit is used for processing the air inlet flow and the fuel flow to obtain an ideal exhaust flow value corresponding to the air inlet flow.
9. A storage medium comprising stored instructions, wherein the instructions, when executed, control a device in which the storage medium is located to perform the urea injection control method according to any one of claims 1-6.
10. An electronic device comprising a memory and one or more instructions, wherein the one or more instructions are stored in the memory and configured to be executed by the one or more processors to perform the urea injection control method of any one of claims 1-6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410030094.0A CN117685081A (en) | 2024-01-09 | 2024-01-09 | Urea injection control method and device, storage medium and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410030094.0A CN117685081A (en) | 2024-01-09 | 2024-01-09 | Urea injection control method and device, storage medium and electronic equipment |
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| CN117685081A true CN117685081A (en) | 2024-03-12 |
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| CN202410030094.0A Pending CN117685081A (en) | 2024-01-09 | 2024-01-09 | Urea injection control method and device, storage medium and electronic equipment |
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| Country | Link |
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| CN (1) | CN117685081A (en) |
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- 2024-01-09 CN CN202410030094.0A patent/CN117685081A/en active Pending
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