SCR inlet pressure threshold MAP creation and urea crystallization identification method

Abstract

The invention relates to the technical field of engine control, and discloses an SCR inlet pressure threshold MAP creation and urea crystallization identification method, which comprises the following steps: selecting SCR fault parts respectively corresponding to a plurality of urea crystallization degrees, and repeatedly executing SCR inlet pressure threshold MAP creation operation to obtain MAPs respectively corresponding to the plurality of urea crystallization degrees, an SCR fault piece corresponding to the current urea crystallization degree is installed on test equipment, the test equipment provided with the SCR fault piece corresponding to the current urea crystallization degree is tested under different operation conditions, SCR inlet pressure corresponding to the current urea crystallization degree under the different operation conditions is obtained, and then MAP corresponding to the current urea crystallization degree is created. Compared with the prior art, crystallization is not needed to be judged through an NOx sensor, the cost is saved, the SCR inlet pressure threshold value is calibrated according to the engine exhaust flow and the SCR temperature, and the SCR crystallization misjudgment rate caused by external complex factors can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of engine control, and in particular to a method for establishing an SCR inlet pressure threshold MAP and identifying urea crystals. Background Art

[0002] In response to the National V and National VI emission regulations for road vehicles and the National IV emission regulations for non-road vehicles, diesel engines generally use a selective catalytic reduction (SCR) as a NOx emission treatment device, that is, urea is sprayed into the SCR mixer through a urea nozzle to decompose into ammonia, and reacts with NOx in the exhaust gas under the action of the SCR catalyst to produce H2O and N2. However, when the engine exhaust temperature is low or the urea nozzle fails, urea crystallization is likely to occur, which in turn causes a series of adverse consequences such as increased engine back pressure, increased fuel consumption, decreased power, and increased tail NOx.

[0003] The traditional solution for judging whether there is urea crystallization in the SCR is to detect the upstream and downstream NOx concentration values ​​through the SCR upstream and downstream NOx sensors, obtain the SCR conversion efficiency and timely obtain the diesel particulate filter (DPF) post-pressure value, and judge whether there is crystallization in the SCR system according to the SCR conversion efficiency threshold and the DPF post-pressure threshold. However, this solution requires the vehicle to be equipped with SCR upstream and downstream NOx sensors, which is costly for road National V or non-road National IV vehicles. In addition, this solution judges crystallization by combining the SCR conversion efficiency threshold and the DPF post-pressure threshold. However, the SCR conversion efficiency is affected by non-crystallization factors such as the urea injection system and the degradation of the SCR carrier. The DPF post-pressure measurement value is affected by non-crystallization factors such as the environment (such as ambient temperature, ambient pressure, etc.), exhaust temperature, SCR and DPF carrier production consistency, and no relevant correction is made to the DPF post-pressure threshold. Therefore, the above solution may have a risk of misjudgment of crystallization. Summary of the invention

[0004] In view of this, the present invention provides a method for creating an SCR inlet pressure threshold MAP and identifying urea crystals to solve the problem that the cost of installing a NOx sensor is high and the influence of non-crystallization factors such as exhaust temperature and ambient pressure are not considered, which may lead to misjudgment of crystallization.

[0005] In a first aspect, the present invention provides a method for creating an SCR inlet pressure threshold MAP, the method comprising: selecting SCR faulty parts corresponding to a plurality of urea crystallization degrees, and repeatedly performing SCR inlet pressure threshold MAP creation operations until MAPs corresponding to a plurality of urea crystallization degrees are obtained, wherein the MAP corresponding to the urea crystallization degree indicates the SCR inlet pressure threshold corresponding to the urea crystallization degree under different operating conditions, the operating conditions at least including the SCR temperature and the exhaust flow of the engine, the SCR inlet pressure threshold MAP creation operation comprising: installing an SCR faulty part corresponding to the current urea crystallization degree on a test device, the test device comprising a test bench or a test vehicle; performing tests under different operating conditions on the test device equipped with the SCR faulty part corresponding to the current urea crystallization degree, obtaining the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and creating the MAP corresponding to the current urea crystallization degree according to the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions.

[0006] The SCR inlet pressure threshold MAP creation method provided by the present invention obtains MAPs corresponding to multiple urea crystallization degrees by selecting SCR fault parts corresponding to multiple urea crystallization degrees, and repeatedly performing SCR inlet pressure threshold MAP creation operations, wherein an SCR fault part corresponding to the current urea crystallization degree is installed on a test device, and the test device installed with the SCR fault part corresponding to the current urea crystallization degree is tested under different operating conditions to obtain the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and then create a MAP corresponding to the current urea crystallization degree, without judging crystallization through a NOx sensor, saving costs, and the SCR inlet pressure is calibrated according to the engine exhaust flow and the SCR temperature, which can reduce the SCR crystallization misjudgment rate caused by complex external factors.

[0007] In an optional embodiment, the SCR inlet pressure threshold corresponding to the corresponding urea crystallization degree under the corresponding operating condition is one of the following: the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition, or the sum of the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition and a preset margin value.

[0008] The present invention allows certain fluctuations or deviations in performance in actual operation by increasing the error range without affecting the overall judgment of the urea crystallization degree.

[0009] In an optional embodiment, the method further includes: testing a test device equipped with an SCR fault component corresponding to the current urea crystallization degree under different operating conditions and in different environments to obtain an inlet pressure corresponding to the current urea crystallization degree when the test device is in different environments and under different operating conditions, wherein the test device in different environments at least includes different ambient pressures, ambient temperatures, and ambient humidity; based on the inlet pressure corresponding to the current urea crystallization degree under different operating conditions when the test device is in different environments, determining a correction value of the inlet pressure corresponding to the current urea crystallization degree under different operating conditions in different environments relative to a preset standard environment.

[0010] The present invention can correct the SCR inlet pressure MAP according to different environments, or only store the MAP corresponding to various urea crystallization degrees under the standard environment, and store the correction values ​​in other environments, thereby saving storage resources.

[0011] In a second aspect, the present invention provides a urea crystal identification method, the method comprising: obtaining a current operating condition and an SCR inlet pressure value of a target vehicle; extracting SCR inlet pressure thresholds corresponding to a plurality of urea crystallization degrees under the current operating condition from MAPs corresponding to a plurality of urea crystallization degrees, the MAPs corresponding to the plurality of urea crystallization degrees being created by the SCR inlet pressure threshold MAP creation method described in the first aspect or any embodiment; comparing the current SCR inlet pressure value of the target vehicle with the SCR inlet pressure thresholds corresponding to the plurality of urea crystallization degrees, to determine the current urea crystallization degree of the target vehicle.

[0012] The present invention obtains the current operating condition and SCR inlet pressure value, and then extracts the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition from the MAPs corresponding to the various urea crystallization degrees, compares the current SCR inlet pressure value with the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees, and then determines the current urea crystallization degree of the target vehicle, thereby realizing accurate and timely identification of urea crystals.

[0013] In an optional embodiment, before obtaining the current operating condition and SCR inlet pressure value of the target vehicle, the method further includes: obtaining the current exhaust flow rate change rate of the target vehicle, and comparing the current exhaust flow rate change rate with a preset exhaust flow rate change rate threshold; if the current exhaust flow rate change rate is less than the preset exhaust flow rate change rate threshold, obtaining the current engine mode; if the engine mode is a normal mode, executing the step of obtaining the current operating condition and SCR inlet pressure value of the target vehicle, and the normal mode indicates that the engine throttle is fully open and there is no afterspray.

[0014] The present invention performs the operation of determining the degree of urea crystallization only when it is determined that the engine is in a steady-state operating condition and the engine is in a normal mode, thereby ensuring that driving regeneration can be triggered normally.

[0015] In an optional embodiment, the method further includes: determining a corresponding driving regeneration time based on different preset driving regeneration times corresponding to different urea crystallization degrees and a current urea crystallization degree of the target vehicle; and triggering driving regeneration of the target vehicle based on the corresponding driving regeneration time.

[0016] The present invention triggers driving regeneration with different driving regeneration durations based on different urea crystallization degrees, thereby achieving targeted driving regeneration and ensuring effective removal of particulate matter.

[0017] In an optional embodiment, extracting the SCR inlet pressure thresholds corresponding to the multiple urea crystallization degrees under the current operating condition from the MAPs corresponding to the multiple urea crystallization degrees includes: acquiring the current environment corresponding to the target vehicle; determining the corresponding correction value based on different correction values ​​corresponding to the preset different environments and the current environment of the target vehicle; correcting the MAPs corresponding to the multiple urea crystallization degrees based on the determined correction value to obtain the target MAPs corresponding to the multiple urea crystallization degrees; extracting the SCR inlet pressure thresholds corresponding to the multiple urea crystallization degrees under the current operating condition from the target MAPs corresponding to the multiple urea crystallization degrees.

[0018] The present invention corrects the MAP corresponding to various urea crystallization degrees based on the correction value corresponding to the current environment of the target vehicle, and then extracts the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating conditions from the corrected MAP, thereby improving the accuracy of urea crystallization degree recognition.

[0019] In a third aspect, the present invention provides an SCR inlet pressure threshold MAP creation device, the device comprising: a MAP creation module, used to select SCR fault parts corresponding to multiple urea crystallization degrees, and repeatedly perform SCR inlet pressure threshold MAP creation operations until MAPs corresponding to multiple urea crystallization degrees are obtained, wherein the MAP corresponding to the urea crystallization degree indicates the SCR inlet pressure threshold corresponding to the urea crystallization degree under different operating conditions, and the operating conditions at least include SCR temperature and engine exhaust flow, and the SCR inlet pressure threshold MAP creation operation includes: installing an SCR fault part corresponding to the current urea crystallization degree on a test device, and the test device includes a test bench or a test vehicle; a vehicle test module, used to test the test device equipped with the SCR fault part corresponding to the current urea crystallization degree under different operating conditions, to obtain the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and create a MAP corresponding to the current urea crystallization degree according to the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions.

[0020] In a fourth aspect, the present invention provides a urea crystal identification device, the device comprising: a current parameter acquisition module, used to obtain a current operating condition and an SCR inlet pressure value of a target vehicle; an inlet pressure threshold extraction module, used to extract, from MAPs corresponding to multiple urea crystallization degrees, SCR inlet pressure thresholds corresponding to multiple urea crystallization degrees under the current operating condition, wherein the MAPs corresponding to the multiple urea crystallization degrees are created by the SCR inlet pressure threshold MAP creation device described in the third aspect; a urea crystal identification module, used to compare the current SCR inlet pressure value of the target vehicle with the SCR inlet pressure thresholds corresponding to the multiple urea crystallization degrees, to determine the current urea crystallization degree of the target vehicle.

[0021] In a fifth aspect, the present invention provides a vehicle, comprising a controller, wherein the controller comprises: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, computer instructions are stored in the memory, and the processor executes the urea crystal identification method of the second aspect or any corresponding embodiment thereof by executing the computer instructions.

[0022] In a sixth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the SCR inlet pressure threshold MAP creation method of the first aspect or any corresponding embodiment thereof, or to execute the urea crystal identification method of the second aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is a flow chart of a method for creating an SCR inlet pressure threshold MAP according to an embodiment of the present invention;

[0025] Figure 2 is a flowchart of a method for creating an SCR inlet pressure threshold MAP and identifying urea crystals according to an embodiment of the present invention;

[0026] Figure 3 is a schematic flow chart of a urea crystal identification method according to an embodiment of the present invention;

[0027] Figure 4 is a structural block diagram of a device for creating an SCR inlet pressure threshold MAP according to an embodiment of the present invention;

[0028] Figure 5 is a structural block diagram of a urea crystal identification device according to an embodiment of the present invention;

[0029] Figure 6 is a structural block diagram of a vehicle according to an embodiment of the present invention;

[0030] Figure 7 Schematic diagram of the hardware structure of the controller according to the embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] According to an embodiment of the present invention, an embodiment of a method for creating an SCR inlet pressure threshold MAP and identifying urea crystals is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] In this embodiment, a method for creating an SCR inlet pressure threshold MAP is provided, which can be used for the above-mentioned controller. Figure 1 : is a flow chart of a method for creating an SCR inlet pressure threshold MAP according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0034] Step S101, selecting SCR fault parts corresponding to multiple urea crystallization degrees, and repeatedly performing SCR inlet pressure threshold MAP creation operation until MAPs corresponding to multiple urea crystallization degrees are obtained, wherein the MAP corresponding to the urea crystallization degree indicates the SCR inlet pressure threshold corresponding to the urea crystallization degree under different operating conditions, and the operating conditions at least include the SCR temperature and the exhaust flow of the engine.

[0035] The SCR inlet pressure threshold MAP creation operation includes: installing an SCR fault component corresponding to the current urea crystallization degree on the test equipment.

[0036] The test equipment includes a test bench or a test vehicle.

[0037] The embodiment of the present invention can pre-select an acceptable SCR fault component that affects engine performance and emission. SCR fault components with different fault degrees correspond to different urea crystallization degrees, wherein the urea crystallization degree can be divided into N different degrees of crystallization such as mild, moderate and severe crystallization, which can be set according to actual needs. Generally, each urea crystallization degree can select its corresponding SCR fault component for subsequent testing, which is only for example; first, the SCR fault component corresponding to the current urea crystallization degree can be installed on a test bench or an engine exhaust system of a test vehicle, wherein the test bench refers to a test bench that can be created through a simulation test, and the MAP corresponding to the current urea crystallization degree is obtained based on the test bench simulation, and the engine exhaust system of the test vehicle refers to an actual vehicle test, and the MAP corresponding to the current urea crystallization degree is obtained through the actual vehicle test, which is only for example, and then any other SCR fault component corresponding to the urea crystallization degree is installed on the test bench or the engine exhaust system of the test vehicle, and the operation of creating the SCR inlet pressure threshold MAP is repeatedly performed until the MAPs corresponding to the various urea crystallization degrees are obtained.

[0038] Step S102, testing the test equipment equipped with the SCR fault part corresponding to the current urea crystallization degree under different operating conditions, obtaining the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and creating a MAP corresponding to the current urea crystallization degree according to the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions.

[0039] like Figure 2As shown, the operating conditions of the embodiment of the present invention may include but are not limited to the SCR temperature and the exhaust flow of the engine, and may also include temperature pressure and vehicle driving state. The operating condition parameters are set according to actual needs. This is only an example, and the method for obtaining the SCR inlet pressure is not limited. For example, Figure 2 As shown, the current single-mode differential pressure sensor can be replaced with a dual-mode differential pressure sensor to obtain the SCR inlet pressure in real time. Alternatively, an SCR inlet pressure sensor can be added based on the single-mode differential pressure sensor. The SCR inlet pressure model can also be calibrated (that is, the SCR inlet pressure model can be calibrated according to the ambient pressure, SCR temperature and exhaust flow rate. The specific calibration method can refer to the Bosch exhaust back pressure model logic, which will not be repeated here). This is just an example. Compared with the traditional method of identifying urea crystals through the upstream and downstream NOx sensors of the SCR equipped on the vehicle, the cost is simpler and the structure is simpler.

[0040] The embodiment of the present invention performs tests under different operating conditions on a test device equipped with an SCR fault component corresponding to the current urea crystallization degree, and obtains the SCR inlet pressure corresponding to the current urea crystallization degree of the engine under different operating conditions. Then, the exhaust flow rate and the SCR temperature can be used as the horizontal and vertical coordinates of the MAP, and the SCR inlet pressure is used as the SCR inlet pressure threshold corresponding to the horizontal and vertical coordinates, and is filled into the MAP, so that the MAP corresponding to the current urea crystallization degree can be obtained. According to the above method, the MAP corresponding to various urea crystallization degrees can be obtained.

[0041] The SCR inlet pressure threshold MAP creation method provided by the present invention obtains MAPs corresponding to multiple urea crystallization degrees by selecting SCR fault parts corresponding to multiple urea crystallization degrees, and repeatedly performing SCR inlet pressure threshold MAP creation operations, wherein an SCR fault part corresponding to the current urea crystallization degree is installed on a test device, and the test device installed with the SCR fault part corresponding to the current urea crystallization degree is tested under different operating conditions to obtain the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and then create a MAP corresponding to the current urea crystallization degree, without judging crystallization through a NOx sensor, saving costs, and the SCR inlet pressure is calibrated according to the engine exhaust flow and the SCR temperature, which can reduce the SCR crystallization misjudgment rate caused by complex external factors.

[0042] In an optional embodiment, the SCR inlet pressure threshold corresponding to the corresponding urea crystallization degree under the corresponding operating condition is one of the following: the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition, or the sum of the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition and a preset margin value.

[0043] In the embodiment of the present invention, the acquired SCR inlet pressure can be directly filled into the MAP corresponding to the corresponding urea crystallization degree, or the acquired SCR inlet pressure can be added to a preset margin value and then filled into the MAP corresponding to the corresponding urea crystallization degree. By increasing the error range, a certain fluctuation or deviation in the actual operation performance is allowed without affecting the overall judgment of the urea crystallization degree.

[0044] In an optional embodiment, a test device equipped with an SCR fault component corresponding to the current urea crystallization degree is tested under different operating conditions and in different environments to obtain an inlet pressure corresponding to the current urea crystallization degree when the test device is in different environments and under different operating conditions, and the different environments of the test device at least include different ambient pressures, ambient temperatures and ambient humidity; based on the inlet pressure corresponding to the current urea crystallization degree when the test device is in different environments and under different operating conditions, a correction value of the inlet pressure corresponding to the current urea crystallization degree under different operating conditions in different environments relative to a preset standard environment is determined.

[0045] The embodiment of the present invention can test the test bench or the test vehicle in different environments and under different operating conditions to obtain MAPs corresponding to various urea crystallization degrees, wherein the environment may include environmental pressure, environmental temperature, and environmental humidity, etc., which are examples only and not limited thereto. Finally, MAPs corresponding to various urea crystallization degrees corresponding to the test equipment in different environments are obtained. In order to save the capacity of MAP storage, a MAP corresponding to various urea crystallization degrees in a standard environment can be selected in advance from the MAPs corresponding to various urea crystallization degrees in all environments. There is no limitation on how to select the standard environment, and one environment can be randomly selected as the standard environment, which is examples only. Then, the correction values ​​of the MAPs corresponding to various urea crystallization degrees in the environments of different vehicles relative to the standard environment can be calculated, which is examples only.

[0046] The present invention can correct the SCR inlet pressure MAP according to different environments, or only store the MAP corresponding to various urea crystallization degrees under the standard environment, and store the correction values ​​in other environments, thereby saving storage resources.

[0047] In this embodiment, a urea crystal identification method is provided, which can be used in a controller. Figure 3 is a flow chart of a urea crystal identification method according to an embodiment of the present invention, such as Figure 3 As shown, the process includes the following steps:

[0048] Step S301, obtaining the current operating condition and SCR inlet pressure value of the target vehicle.

[0049] The embodiment of the present invention can obtain the current operating conditions of the target vehicle, wherein the operating conditions include the SCR temperature and the exhaust flow of the engine, and the current SCR inlet pressure value can be obtained through the SCR inlet pressure sensor or the calibrated SCR inlet pressure model or the dual-mode pressure difference sensor.

[0050] Step S302, extracting the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition from the MAPs corresponding to the various urea crystallization degrees, wherein the MAPs corresponding to the various urea crystallization degrees are created by using the SCR inlet pressure threshold MAP creation method in the above embodiment.

[0051] The embodiment of the present invention can extract the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating conditions from the MAP weights corresponding to the various urea crystallization degrees.

[0052] Specifically, the SCR inlet pressure threshold values ​​corresponding to the various urea crystallization degrees under the current operating condition are extracted from the MAPs corresponding to the various urea crystallization degrees, including: obtaining the current environment corresponding to the target vehicle; determining the corresponding correction value based on different correction values ​​corresponding to the preset different environments and the current environment of the target vehicle; correcting the MAPs corresponding to the various urea crystallization degrees based on the determined correction value to obtain the target MAPs corresponding to the various urea crystallization degrees; and extracting the SCR inlet pressure threshold values ​​corresponding to the various urea crystallization degrees under the current operating condition from the target MAPs corresponding to the various urea crystallization degrees.

[0053] The embodiment of the present invention can obtain the current environment corresponding to the target vehicle through an environmental pressure sensor, an environmental temperature sensor, an environmental humidity sensor, etc., and determine the corresponding correction value based on the current environment and different correction values ​​corresponding to different pre-calibrated environments. The MAP corresponding to the stored multiple urea crystallization degrees can be corrected based on the determined correction value to obtain the corrected target MAP corresponding to the multiple urea crystallization degrees. Finally, the SCR inlet pressure thresholds corresponding to the multiple urea crystallization degrees under the current operating conditions can be extracted from the corrected target MAP corresponding to the multiple urea crystallization degrees.

[0054] The present invention corrects the MAP corresponding to various urea crystallization degrees based on the correction value corresponding to the current environment of the target vehicle, and then extracts the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating conditions from the corrected MAP, thereby improving the accuracy of urea crystallization degree recognition.

[0055] Step S303, comparing the current SCR inlet pressure value of the target vehicle with the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees, to determine the current urea crystallization degree of the target vehicle.

[0056] In an embodiment of the present invention, the current SCR inlet pressure value of the target vehicle can be compared with the SCR inlet pressure thresholds corresponding to the extracted multiple urea crystallization degrees. The comparison method can be to determine that the current SCR inlet pressure value is greater than a certain SCR inlet pressure threshold, and then the current urea crystallization degree is determined to be the urea crystallization degree corresponding to the certain SCR inlet pressure threshold. This is only used as an example and is not limited.

[0057] The present invention obtains the current operating condition and SCR inlet pressure value, and then extracts the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition from the MAPs corresponding to the various urea crystallization degrees, compares the current SCR inlet pressure value with the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees, and then determines the current urea crystallization degree of the target vehicle, thereby realizing accurate and timely identification of urea crystals.

[0058] In an optional embodiment, before obtaining the current operating condition and SCR inlet pressure value of the target vehicle, the current exhaust flow rate change rate of the target vehicle is obtained, and the current exhaust flow rate change rate is compared with a preset exhaust flow rate change rate threshold; if the current exhaust flow rate change rate is less than the preset exhaust flow rate change rate threshold, the current engine mode is obtained; if the engine mode is normal mode, the step of obtaining the current operating condition and SCR inlet pressure value of the target vehicle is executed, and the normal mode indicates that the engine throttle is fully open and there is no afterspray.

[0059] like Figure 2 As shown, the embodiment of the present invention can obtain the current exhaust flow rate change rate of the target vehicle, and then compare the current exhaust flow rate change rate with a preset exhaust flow rate change rate threshold, wherein the setting method of the preset exhaust flow rate change rate threshold is not limited, and the exhaust flow rate change rate threshold can be calibrated in combination with an engine bench or a whole vehicle test, or can be set based on the practical experience of the staff. For example only, if the current exhaust flow rate change rate is less than the preset exhaust flow rate change rate threshold, it is determined that the engine operating condition is a steady-state condition, and then the controller can read the engine mode, wherein the engine mode can be divided into a normal mode, a thermal management mode, and a regeneration mode. The normal model code is 100001, which indicates that the engine throttle is fully open and there is no after-injection. For example only, when it is determined that the engine operating condition is a steady-state condition and the engine mode is a normal mode, the current operating condition and SCR inlet pressure value of the target vehicle can be obtained automatically, and the SCR inlet pressure value under the current operating condition is compared with the inlet pressure threshold value found by multiple urea crystallization degree MAP under the current operating condition. If it is greater than a certain inlet pressure threshold, it is determined that the current urea crystallization is a crystallization of the crystallization degree corresponding to the threshold, and can be represented by a defined variable. Please refer to the above embodiment for detailed description, which will not be repeated here.

[0060] The present invention performs the operation of determining the degree of urea crystallization only when it is determined that the engine is in a steady-state operating condition and the engine is in a normal mode, thereby ensuring that driving regeneration can be triggered normally.

[0061] In an optional embodiment, based on the preset different driving regeneration times corresponding to different urea crystallization degrees and the current urea crystallization degree of the target vehicle, the corresponding driving regeneration time is determined; based on the corresponding driving regeneration time, the driving regeneration of the target vehicle is triggered.

[0062] In the embodiment of the present invention, different driving regeneration times can be calibrated in advance in combination with different urea crystallization degrees, and the corresponding relationship between different urea crystallization degrees and different driving regeneration times can be obtained, such as Figure 2 As shown, after determining the current urea crystallization degree of the target vehicle, the corresponding driving regeneration time (i.e., the time when the exhaust temperature exceeds the set value) is determined based on the preset different urea crystallization degrees corresponding to the different driving regeneration times. Finally, based on the determined driving regeneration time, the driving regeneration of the target vehicle can be triggered by the set triggering method.

[0063] The present invention triggers driving regeneration with different driving regeneration durations based on different urea crystallization degrees, thereby achieving targeted driving regeneration and ensuring effective removal of particulate matter.

[0064] In this embodiment, a device for creating an SCR inlet pressure threshold MAP and identifying urea crystals is also provided, which is used to implement the above-mentioned embodiments and preferred implementations, and will not be repeated for what has been described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0065] This embodiment provides a device for creating a SCR inlet pressure threshold MAP. Figure 4 As shown, including:

[0066] The MAP creation module 401 is used to select SCR faulty parts corresponding to multiple urea crystallization degrees, and repeatedly perform SCR inlet pressure threshold MAP creation operations until MAPs corresponding to multiple urea crystallization degrees are obtained, wherein the MAP corresponding to the urea crystallization degree indicates the SCR inlet pressure threshold corresponding to the urea crystallization degree under different operating conditions, and the operating conditions at least include the SCR temperature and the exhaust flow of the engine. The SCR inlet pressure threshold MAP creation operation includes: installing the SCR faulty part corresponding to the current urea crystallization degree on the test equipment, and the test equipment includes a test bench or a test vehicle; the vehicle test module 402 is used to test the test equipment installed with the SCR faulty part corresponding to the current urea crystallization degree under different operating conditions, obtain the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and create the MAP corresponding to the current urea crystallization degree according to the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions.

[0067] In some optional embodiments, the SCR inlet pressure threshold corresponding to the corresponding urea crystallization degree under the corresponding operating condition is one of the following: the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition, or the sum of the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition and a preset margin value.

[0068] In some optional embodiments, the SCR inlet pressure threshold MAP creation device further includes: an environmental testing module, which is used to test a test device equipped with an SCR fault component corresponding to the current urea crystallization degree under different operating conditions and in different environments, and obtain an inlet pressure corresponding to the current urea crystallization degree under different environments and different operating conditions when the test device is in different environments, and the test device in different environments at least includes different environmental pressures, environmental temperatures and environmental humidity; a correction determination module, which is used to determine, based on the inlet pressure corresponding to the current urea crystallization degree under different environments and different operating conditions when the test device is in different environments and different operating conditions, a correction value of the inlet pressure corresponding to the current urea crystallization degree under different operating conditions under a preset standard environment.

[0069] This embodiment also provides a urea crystal identification device, such as Figure 5As shown, it includes: a current parameter acquisition module 501, which is used to obtain the current operating condition and SCR inlet pressure value of the target vehicle; an inlet pressure threshold extraction module 502, which is used to extract the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition from the MAPs corresponding to the various urea crystallization degrees, and the MAPs corresponding to the various urea crystallization degrees are created by the SCR inlet pressure threshold MAP creation device; a urea crystal identification module 503, which is used to compare the current SCR inlet pressure value of the target vehicle with the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees, and determine the current urea crystallization degree of the target vehicle.

[0070] In some optional embodiments, before obtaining the current operating condition and SCR inlet pressure value of the target vehicle, the urea crystallization identification device further includes: a change rate comparison module, used to obtain the current exhaust flow change rate of the target vehicle, and compare the current exhaust flow change rate with a preset exhaust flow change rate threshold; an engine mode acquisition module, used to obtain the current engine mode if the current exhaust flow change rate is less than the preset exhaust flow change rate threshold; a parameter acquisition module, used to execute the step of obtaining the current operating condition and SCR inlet pressure value of the target vehicle if the engine mode is a normal mode, and the normal mode indicates that the engine throttle is fully open and there is no afterspray.

[0071] In some optional embodiments, the urea crystallization identification device further includes: a driving regeneration time determination module, which is used to determine the corresponding driving regeneration time based on different preset urea crystallization degrees corresponding to different driving regeneration times and the current urea crystallization degree of the target vehicle; and a driving regeneration triggering module, which is used to trigger the driving regeneration of the target vehicle based on the corresponding driving regeneration time.

[0072] In some optional embodiments, the inlet pressure threshold extraction module 502 includes: an environment acquisition unit, which is used to acquire the current environment corresponding to the target vehicle; a correction value determination unit, which is used to determine the corresponding correction value based on different correction values ​​corresponding to different preset environments and the current environment of the target vehicle; a MAP correction unit, which is used to correct the MAP corresponding to the various urea crystallization degrees based on the determined correction value to obtain the target MAP corresponding to the various urea crystallization degrees; and a threshold extraction unit, which is used to extract the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating conditions from the target MAP corresponding to the various urea crystallization degrees.

[0073] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0074] The SCR inlet pressure threshold MAP creation device and the urea crystallization identification device in this embodiment are presented in the form of functional units, where the units refer to ASIC (Application Specific Integrated Circuit) circuits, processors and memories that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0075] The embodiment of the present invention further provides a vehicle, such as Figure 6 As shown, the vehicle includes a controller having the above Figure 5 Urea crystal identification device.

[0076] Specifically, the vehicle may include but is not limited to heavy trucks, trailers, excavators, anchor diggers, bulldozers, road rollers, concrete pumps and other work vehicles.

[0077] See also Figure 7 , Figure 7 is a schematic diagram of the structure of a controller provided by an optional embodiment of the present invention, such as Figure 7 As shown, the controller includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the controller, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple controllers can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 7 A processor 10 is taken as an example.

[0078] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0079] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0080] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required by at least one function; the data storage area may store data created according to the use of the controller, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the controller via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0081] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0082] The controller also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 7 The example of connecting through bus is taken in the following.

[0083] The input device 30 can receive input digital or character information and generate key signal input related to the user settings and function control of the controller, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0084] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0085] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the defined scope.

Claims

1. A method for creating an SCR inlet pressure threshold MAP, characterized in that: The method comprises: SCR fault parts corresponding to multiple urea crystallization degrees are selected, and the SCR inlet pressure threshold MAP creation operation is repeatedly performed until the MAPs corresponding to the multiple urea crystallization degrees are obtained, wherein the MAP corresponding to the urea crystallization degree indicates the SCR inlet pressure threshold corresponding to the urea crystallization degree under different operating conditions, and the operating conditions at least include the SCR temperature and the exhaust flow of the engine. The SCR inlet pressure threshold MAP creation operation includes: Installing an SCR fault component corresponding to the current urea crystallization degree on a test device, wherein the test device includes a test bench or a test vehicle; The test equipment equipped with the SCR fault part corresponding to the current urea crystallization degree is tested under different operating conditions to obtain the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and the MAP corresponding to the current urea crystallization degree is created according to the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions.

2. The method according to claim 1, characterized in that The SCR inlet pressure threshold corresponding to the corresponding urea crystallization degree under the corresponding operating condition is one of the following: the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition, or the sum of the SCR inlet pressure corresponding to the corresponding urea crystallization degree under the corresponding operating condition and a preset margin value.

3. The method according to claim 1, characterized in that The method further comprises: Performing tests on a test device equipped with an SCR fault component corresponding to the current urea crystallization degree under different operating conditions and in different environments to obtain an inlet pressure corresponding to the current urea crystallization degree under different operating conditions and in different environments of the test device, wherein the different environments of the test device at least include different environmental pressures, environmental temperatures, and environmental humidity; Based on the inlet pressure corresponding to the current urea crystallization degree under different operating conditions when the test equipment is in different environments, the correction value of the inlet pressure corresponding to the current urea crystallization degree under different operating conditions under different environments relative to the preset standard environment is determined.

4. A method for identifying urea crystals, characterized in that: The method comprises: Obtain the current operating condition and SCR inlet pressure value of the target vehicle; Extracting, from the MAPs corresponding to the various urea crystallization degrees, the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition, wherein the MAPs corresponding to the various urea crystallization degrees are created by the SCR inlet pressure threshold MAP creation method according to any one of claims 1 to 3; The current SCR inlet pressure value of the target vehicle is compared with the SCR inlet pressure thresholds corresponding to the multiple urea crystallization degrees, so as to determine the current urea crystallization degree of the target vehicle.

5. The method according to claim 4, characterized in that Before obtaining the current operating condition and SCR inlet pressure value of the target vehicle, the method further includes: Acquire a current exhaust flow rate change rate of the target vehicle, and compare the current exhaust flow rate change rate with a preset exhaust flow rate change rate threshold; If the current exhaust flow rate change rate is less than a preset exhaust flow rate change rate threshold, obtaining the current engine mode; If the engine mode is a normal mode, the step of obtaining the current operating condition of the target vehicle and the SCR inlet pressure value is performed, and the normal mode indicates that the engine throttle is fully open and there is no after-injection.

6. The method according to claim 4, characterized in that The method further comprises: Determine the corresponding driving regeneration time based on the preset different urea crystallization degrees corresponding to different driving regeneration times and the current urea crystallization degree of the target vehicle; Based on the corresponding driving regeneration duration, driving regeneration of the target vehicle is triggered.

7. The method according to claim 4, characterized in that The extracting, from the MAPs corresponding to the various urea crystallization degrees, the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition, includes: Get the current environment corresponding to the target vehicle; Determine the corresponding correction value based on different correction values ​​corresponding to different preset environments and the current environment of the target vehicle; Based on the determined correction value, the MAP corresponding to the multiple urea crystallization degrees is corrected to obtain the target MAP corresponding to the multiple urea crystallization degrees; The SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition are extracted from the target MAPs corresponding to the various urea crystallization degrees.

8. A device for creating a SCR inlet pressure threshold MAP, characterized in that: The device comprises: A MAP creation module is used to select SCR faulty parts corresponding to a plurality of urea crystallization degrees, and repeatedly perform an SCR inlet pressure threshold MAP creation operation until a MAP corresponding to a plurality of urea crystallization degrees is obtained, wherein the MAP corresponding to the urea crystallization degree indicates an SCR inlet pressure threshold corresponding to the urea crystallization degree under different operating conditions, the operating conditions at least including an SCR temperature and an exhaust flow rate of an engine, and the SCR inlet pressure threshold MAP creation operation includes: installing an SCR faulty part corresponding to a current urea crystallization degree on a test device, the test device including a test bench or a test vehicle; The vehicle test module is used to test the test equipment equipped with the SCR fault part corresponding to the current urea crystallization degree under different operating conditions, obtain the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions, and create a MAP corresponding to the current urea crystallization degree according to the SCR inlet pressure corresponding to the current urea crystallization degree under different operating conditions.

9. A urea crystal identification device, characterized in that: The device comprises: The current parameter acquisition module is used to obtain the current operating conditions and SCR inlet pressure value of the target vehicle; an inlet pressure threshold extraction module, used to extract the SCR inlet pressure thresholds corresponding to the various urea crystallization degrees under the current operating condition from the MAPs corresponding to the various urea crystallization degrees, wherein the MAPs corresponding to the various urea crystallization degrees are created by the SCR inlet pressure threshold MAP creation device according to claim 8; The urea crystallization identification module is used to compare the current SCR inlet pressure value of the target vehicle with the SCR inlet pressure thresholds corresponding to the multiple urea crystallization degrees, so as to determine the current urea crystallization degree of the target vehicle.

10. A vehicle, characterized in that: The vehicle includes a controller, and the controller includes: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the urea crystal identification method according to any one of claims 4 to 7 by executing the computer instructions.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, which are used to enable a computer to execute the SCR inlet pressure threshold MAP creation method according to any one of claims 1 to 3, or to execute the urea crystal identification method according to any one of claims 4 to 7.

Images