Method and device for determining fault type of gas-driven urea system in vehicle and vehicle

Abstract

The invention discloses a method and device for determining the fault type of a gas-driven urea system in a vehicle and the vehicle. The method comprises the steps that in response to the situation that the gas-driven urea system is in a first working state, pressure information of a plurality of urea nozzles is obtained; based on the pressure information, the standard pressure information of the urea nozzle and the duty ratio of the urea nozzle, the gas-driven urea system is detected, and a detection result is obtained; and in response to the detection result that the gas-driven urea system is in the fault working state, determining the fault type to which the fault state belongs based on the conversion efficiency of the catalytic reduction system. The technical problem of low fault type determination accuracy of the urea system in the vehicle is solved.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more specifically, to a method, apparatus, and vehicle for determining the fault type of a gas-driven urea system in a vehicle. Background Technology

[0002] Currently, the method for determining the fault type of the urea system in a vehicle mainly involves using the selective catalytic reduction system in the urea system to monitor the urea injection process using multiple sensors. Among these multiple sensors, at least one pressure sensor is used to check whether there are any abnormalities in the pressure changes of the nozzle used during injection, thereby determining whether the urea system is faulty.

[0003] However, the fault identification results obtained using the above methods are insufficient to distinguish the specific causes of the abnormal pressure changes. Furthermore, these methods are susceptible to the effects of component aging and sensor misalignment within the urea system. Therefore, the technical problem of low accuracy in determining the fault type of the urea system in vehicles remains.

[0004] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0005] This application provides a method, apparatus, and vehicle for determining the fault type of a gas-driven urea system in a vehicle, in order to at least solve the technical problem of low accuracy in determining the fault type of a urea system in a vehicle.

[0006] According to one aspect of the embodiments of this application, a method for determining the fault type of a gas-driven urea system in a vehicle is provided. The gas-driven urea system includes multiple urea nozzles and a catalytic reduction system. The method may include: in response to the gas-driven urea system being in a first operating state, acquiring pressure information of the multiple urea nozzles, wherein the first operating state is an injection state in which urea is simultaneously injected into the gas emitted by the vehicle using the multiple urea nozzles, and the pressure information is used to indicate the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea; detecting the gas-driven urea system based on the pressure information, standard pressure information of the urea nozzles, and the duty cycle of the urea nozzles, and obtaining a detection result, wherein the standard pressure information is used to indicate the degree of pressure fluctuation applied to the urea nozzles during the injection of urea when the gas-driven urea system is in a normal operating state; in response to the detection result indicating that the gas-driven urea system is in a faulty operating state, determining the fault type of the fault state based on the conversion efficiency of the catalytic reduction system, wherein the catalytic reduction system is used to convert a first substance in the gas into a second substance using urea, and the degree of pollution of the gas by the first substance is greater than the degree of pollution of the gas by the second substance.

[0007] Furthermore, the method also includes: in response to the gas-driven urea system being in a second operating state, acquiring standard pressure information, wherein the second operating state is used to indicate the state of urea flowing from the urea tank to multiple urea nozzles; and in response to acquiring the standard pressure information, controlling the state of the gas-driven urea system to switch from the second operating state to the first operating state.

[0008] Further, the standard pressure information includes first standard pressure information, which is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the synchronous injection of urea by multiple urea nozzles when the air-driven urea system is in normal operation. Responding to the air-driven urea system being in a second operating state, acquiring the standard pressure information includes: responding to the air-driven urea system being in the second operating state and the absence of first standard pressure information in the vehicle's electronic control unit, controlling multiple urea nozzles to synchronously inject urea at a preset duty cycle; and during the urea injection process, acquiring first pressure change information, a first minimum pressure value, and a first maximum pressure value of the urea nozzles within a preset number of injection cycles, wherein the first pressure change information is used to represent the degree of pressure change of the urea nozzles during synchronous urea injection; determining a first pressure difference between the first maximum pressure value and the first minimum pressure value within the same injection cycle; determining first standard pressure change information of the air-driven urea system based on a preset number of first pressure differences; determining first standard pressure information based on the first standard pressure change information and the remaining urea level; and acquiring the first standard pressure information from the electronic control unit in response to the presence of first standard pressure information in the electronic control unit.

[0009] Furthermore, the standard pressure information includes second standard pressure information, which is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the alternating injection of urea by multiple urea nozzles when the gas-driven urea system is in normal operation. Responding to the gas-driven urea system being in a second operating state, acquiring the standard pressure information includes: responding to the gas-driven urea system being in the second operating state and the absence of second standard pressure information in the vehicle's electronic control unit, controlling multiple urea nozzles to alternately inject urea at a preset duty cycle; and during the urea injection process, acquiring second pressure change information, a second minimum pressure value, and a second maximum pressure value of the urea nozzles within a preset number of injection cycles, wherein the second pressure change information is used to represent the degree of pressure change of the urea nozzles during the alternating injection of urea; determining a second pressure difference between the second maximum pressure value and the second minimum pressure value within the same injection cycle; determining second standard pressure change information of the gas-driven urea system based on a preset number of second pressure differences; determining second standard pressure information based on the second standard pressure change information and the remaining urea level; and acquiring the second standard pressure information from the electronic control unit in response to the presence of second standard pressure information in the electronic control unit.

[0010] Furthermore, in response to the gas-driven urea system being in a first operating state, the pressure information of the urea nozzle is acquired, including: in response to the gas-driven urea system being in a first operating state, acquiring the third minimum pressure and the third maximum pressure of the urea nozzle within a preset number of injection cycles, and acquiring the duty cycle; in response to the duty cycle being within a preset duty cycle range, determining the third pressure difference between the third maximum pressure and the third minimum pressure within the same injection cycle; and determining the pressure information based on the third pressure difference.

[0011] Furthermore, the standard pressure information includes first standard pressure information, which is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the synchronous injection of urea by multiple urea nozzles when the gas-driven urea system is in normal condition. Based on the pressure information, the standard pressure information of the gas-driven urea system, and the duty cycle of the urea nozzles, the gas-driven urea system is detected to obtain the detection result, including: in response to the difference between the pressure information and the first standard pressure information being less than a first threshold, the detection result is determined to be that the gas-driven urea system is in a fault state.

[0012] Furthermore, the standard pressure information includes second standard pressure information, which is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the alternating injection of urea by multiple urea nozzles when the gas-driven urea system is in a normal state. In response to a detection result indicating that the gas-driven urea system is in a fault state, the fault type is determined based on the conversion efficiency of the catalytic reduction system, including: in response to a detection result indicating that the gas-driven urea system is in a fault state, controlling multiple urea nozzles to alternately inject urea at a preset duty cycle, and during the urea injection process, acquiring the fourth pressure of the urea nozzles within a preset number of injection cycles. The minimum and maximum fourth pressure values ​​are determined; the fourth pressure difference between the maximum and minimum fourth pressure values ​​within the same injection cycle is determined; based on the fourth pressure difference, pressure sub-information of the urea nozzles is determined, wherein the pressure sub-information is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during alternating urea injection; in response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, a correction operation is performed on the gas-driven urea system and the catalytic reduction system; the conversion efficiency of the catalytic reduction system after the correction operation is performed is obtained; based on the conversion efficiency, the fault type is determined.

[0013] Furthermore, the fault type includes urea nozzle fault. Based on conversion efficiency, the fault type is determined, including: in response to the conversion efficiency being less than the conversion efficiency threshold, the fault type is determined to be urea nozzle fault.

[0014] Furthermore, the gas-driven urea system includes a urea tank. In response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, a correction operation is performed on the gas-driven urea system, including: increasing the pressure in the urea tank to a preset pressure in response to the difference between the pressure sub-information and the second standard pressure information being less than the first threshold; re-determining the difference between the pressure sub-information and the second standard pressure information; and determining that the correction operation on the gas-driven urea system has been completed in response to the re-determined difference between the pressure sub-information and the second standard pressure information being less than the second threshold.

[0015] Further, a correction operation is performed on the catalytic reduction system, including: adjusting the target ratio in the catalytic reduction system during the correction operation to obtain the adjusted target ratio, wherein the target ratio is used to represent the proportion of the first substance reduced by the catalytic reduction system.

[0016] According to another aspect of the embodiments of this application, a fault type determination device for a gas-driven urea system in a vehicle is also provided. The gas-driven urea system includes multiple urea nozzles and a catalytic reduction system. The device includes: an acquisition unit, configured to acquire pressure information of the multiple urea nozzles in response to the gas-driven urea system being in a first operating state, wherein the first operating state is an injection state in which urea is synchronously injected into the gas discharged from the vehicle using multiple urea nozzles, and the pressure information is used to indicate the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea; and a detection unit, configured to detect the urea nozzles based on the pressure information and the standard pressure of the urea nozzles. The system detects the gas-driven urea system by analyzing information and the duty cycle of the urea nozzle, and obtains the detection results. The standard pressure information is used to indicate the degree of pressure fluctuation applied to the urea nozzle during urea injection when the gas-driven urea system is in normal operating condition. The determination unit is used to determine the fault type of the fault state based on the conversion efficiency of the catalytic reduction system in response to the detection result indicating that the gas-driven urea system is in a faulty operating state. The catalytic reduction system is used to convert a first substance in the gas into a second substance using urea. The degree of pollution of the gas by the first substance is greater than that of the second substance.

[0017] According to another aspect of the embodiments of this application, a vehicle is also provided. The vehicle may include a memory and a processor. The memory stores an executable program. The processor can be used to run the program, wherein, when the program runs, it executes the fault type determination method for the gas-driven urea system in the vehicle described in the embodiments of this application.

[0018] According to another aspect of the embodiments of this application, an electronic device is also provided, the electronic device comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the method of any one of the above when it is running.

[0019] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided. The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to execute the fault type determination method for a gas-driven urea system in a vehicle according to the embodiments of this application.

[0020] According to another aspect of the embodiments of this application, a processor is also provided. The processor is used to run a program, wherein the program, when running, executes the fault type determination method for a gas-driven urea system in a vehicle according to the embodiments of this application.

[0021] According to another aspect of the embodiments of this application, a computer program product is also provided. This computer program product includes a computer program that, when executed by a processor, implements the fault type determination method for the gas-driven urea system in a vehicle as described in the embodiments of this application.

[0022] According to another aspect of the embodiments of this application, a vehicle is also provided. The vehicle may include a memory and a processor. The memory stores an executable program. The processor can be used to run the program, wherein, when the program runs, it executes the fault type determination method for the gas-driven urea system in the vehicle described in the embodiments of this application.

[0023] In this embodiment, in response to the gas-driven urea system being in a first operating state, pressure information from multiple urea nozzles is acquired. Based on the pressure information, the standard pressure information of the urea nozzles, and the duty cycle of the urea nozzles, the gas-driven urea system is detected, and a detection result is obtained. In response to the detection result indicating that the gas-driven urea system is in a faulty operating state, the fault type is determined based on the conversion efficiency of the catalytic reduction system. In other words, in this embodiment, the gas-driven urea system is detected based on the acquired urea nozzle pressure information and the urea nozzle duty cycle, thereby achieving the separation and anomaly identification of the independent operating states of multiple nozzles without relying on multiple pressure sensors or stopping urea injection, thus enabling the determination of whether the gas-driven urea system is faulty. When the gas-driven urea system is in a faulty operating state, this embodiment determines the fault type based on the conversion efficiency of the catalytic reduction system within the gas-driven urea system, effectively eliminating misjudgments caused by sensor drift and device aging, thereby improving the accuracy of fault type determination in vehicle urea systems and solving the technical problem of low accuracy in fault type determination in vehicle urea systems. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 This is a flowchart of a method for determining the fault type of a gas-driven urea system in a vehicle according to an embodiment of this application;

[0026] Figure 2 This is a graph illustrating a diagnostic abnormality of a urea nozzle according to an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of a urea nozzle abnormality diagnosis system according to an embodiment of this application;

[0028] Figure 4 This is a flowchart of a urea system pressure build-up according to an embodiment of this application;

[0029] Figure 5 This is a flowchart of a urea system self-learning according to an embodiment of this application;

[0030] Figure 6 This is a flowchart of monitoring and recording a urea nozzle according to an embodiment of this application;

[0031] Figure 7 This is a flowchart of a urea injection / pressure replenishment process according to an embodiment of this application;

[0032] Figure 8 This is a flowchart illustrating a passive monitoring function of a urea system according to an embodiment of this application;

[0033] Figure 9 This is a flowchart of a urea nozzle blockage diagnosis function according to an embodiment of this application;

[0034] Figure 10 This is a flowchart of a urea system pre-correction function according to an embodiment of this application;

[0035] Figure 11 This is a flowchart of a nitrogen and oxygen feedback correction function after selective reduction system according to an embodiment of this application;

[0036] Figure 12 This is a schematic diagram of a fault type determination device for a gas-driven urea system in a vehicle according to an embodiment of this application. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] According to an embodiment of this application, an embodiment of a method for determining the functional retention time of a dryer canister in a vehicle is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0040] Figure 1 This is a flowchart of a method for determining the fault type of a gas-driven urea system according to an embodiment of this application, such as... Figure 1 As shown, the method may include the following steps.

[0041] Step S102: In response to the air-driven urea system in the vehicle being in the first working state, pressure information of multiple urea nozzles is acquired.

[0042] In the technical solution provided in step S102 of this application, the gas-driven urea system includes multiple urea nozzles and a catalytic reduction system, wherein the catalytic reduction system can be a selective catalytic reduction (SCR) system. The first operating state can be used to represent the injection state in which urea is simultaneously injected into the gas emitted by the vehicle using multiple urea nozzles. The pressure information can be used to represent the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea, and the pressure information can be represented by Paver; the urea nozzle can be any nozzle in the gas-driven urea system used to control the amount of urea injected.

[0043] Optionally, if the pneumatic urea system is in its first operating state, pressure information from multiple urea nozzles can be acquired.

[0044] Optionally, in response to the gas-driven urea system being in its first operating state, a single pressure sensor arranged in the urea liquid path collects sensor signals reflecting pressure fluctuations at multiple urea nozzles during synchronous injection. These collected sensor signals can be used as pressure information. The pressure sensor can be a differential pressure sensor or an absolute pressure sensor arranged in the nozzles and urea transport pipelines.

[0045] In this embodiment of the application, the above step S102 can be used to achieve joint diagnosis of the working status of multiple urea nozzles based solely on the pressure fluctuation of the common liquid path during synchronous injection of dual nozzles using only pressure sensors, thereby improving fault detection capability and diagnostic coverage.

[0046] Step S104: Based on the pressure information, the standard pressure information of the urea nozzle, and the duty cycle of the urea nozzle, the air-driven urea system is tested to obtain the test results.

[0047] In the technical solution provided in step S102 of this application, the aforementioned standard pressure information can be used to represent the degree of pressure fluctuation applied to the urea nozzle during urea injection when the gas-driven urea system is in normal operating condition. This standard pressure information can be represented by EURP_CHECK, where EURP_CHECK_F can represent the standard pressure information of the upstream nozzle, and EURP_CHECK_R can represent the standard pressure information of the downstream nozzle. The aforementioned duty cycle can be used to represent the ratio of the urea nozzle's opening time per unit time to the total cycle time, and the duty cycle can be controlled by the urea nozzle. The aforementioned normal operating condition can be used to represent the operating state of the gas-driven urea system where the urea nozzle is free from blockage and leakage, the injection response is normal, and the pressure fluctuation characteristics are stable. The aforementioned detection results can be used as a diagnostic conclusion for whether multiple urea nozzles are blocked or abnormal.

[0048] Optionally, after obtaining the pressure information, the gas-driven urea system can be tested based on the aforementioned pressure information, the standard pressure information of the urea nozzle, and the duty cycle of the urea nozzle to obtain the test results.

[0049] Optionally, under the current duty cycle condition of the urea nozzle, the standard pressure information corresponding to the aforementioned urea nozzle is obtained; the currently collected pressure information is compared with the aforementioned standard pressure information. If the deviation between the two exceeds a preset tolerance range, it can be determined that at least one of the multiple urea nozzles shows a tendency to become clogged or is abnormal. For example, when the urea nozzle continuously sprays at a 40% duty cycle, the preset tolerance range for pressure fluctuation is ±15 kPa; if the currently measured pressure fluctuation exceeds this range, it can be determined that the nozzle is at risk of becoming clogged.

[0050] It should be noted that the duty cycle of the urea nozzle, the pressure fluctuation range within the preset tolerance range, and the pressure information compared with the standard pressure information mentioned above are only examples, and no specific restrictions are placed on the duty cycle of the urea nozzle or the specific detection method based on the pressure information and the standard pressure information.

[0051] In this embodiment of the application, the above step S104 can be used to realize the health assessment of the collaborative working status of multiple urea nozzles based on the dynamic comparison mechanism of the sampled pressure information and duty cycle, thereby improving the real-time performance and coverage of fault diagnosis.

[0052] Step S106: In response to the detection result that the gas-driven urea system is in a faulty working state, the fault type to which the fault state belongs is determined based on the conversion efficiency of the catalytic reduction system.

[0053] In the technical solution of step S106 of this application, the aforementioned fault operating state can be used to indicate an abnormal operating state in the gas-driven urea system where at least one urea nozzle is clogged, the injection volume is insufficient, or the response is sluggish. The aforementioned conversion efficiency can be used to indicate the conversion rate of reducing a first substance to a second substance (e.g., nitrogen, water vapor) using a catalytic reduction system (e.g., a selective catalytic reduction system). The aforementioned fault types can be urea injection system faults, urea nozzle clogging faults, and urea liquid supply pressure abnormality faults, including but not limited to front-stage nozzle clogging and rear-stage nozzle clogging. The aforementioned catalytic reduction system is used to convert a first substance in a gas into a second substance using urea, where the degree of pollution of the gas by the first substance is greater than the degree of pollution of the gas by the second substance. The aforementioned first substance can include, but is not limited to, nitrogen oxides (which can be represented as NOx). The aforementioned second substance can include, but is not limited to, nitrogen, water vapor, etc. The aforementioned front-stage nozzle can be used to indicate a urea nozzle located upstream of the urea liquid supply line, and the aforementioned rear-stage nozzle can be used to indicate a urea nozzle located downstream of the urea liquid supply line.

[0054] Optionally, when the test results are obtained and the test results indicate that the gas-driven urea system is in a faulty working state, the fault type can be determined based on the conversion efficiency of the catalytic reduction system.

[0055] Optionally, in step S106, in response to the detection result that the gas-driven urea system is in a faulty working state, a multi-dimensional diagnostic logic is established based on the degree of decline in the conversion efficiency of the current catalytic reduction system, combined with the duty cycle of the urea nozzle and the fluctuation of the liquid circuit pressure, to distinguish the abnormal conversion efficiency mode caused by the blockage of the front nozzle and the blockage of the rear nozzle; wherein, the blockage of the front nozzle is more likely to lead to a continuous insufficient overall injection volume and a uniform and continuous decrease in conversion efficiency, while the blockage of the rear nozzle is accompanied by a phased interruption of injection, increased fluctuation of conversion efficiency, or a sudden drop in local reduction efficiency.

[0056] In steps S102 to S106 of this application, in response to the gas-driven urea system being in a first working state, pressure information from multiple urea nozzles is acquired; based on the pressure information, the standard pressure information of the urea nozzles, and the duty cycle of the urea nozzles, the gas-driven urea system is detected to obtain a detection result; in response to the detection result indicating that the gas-driven urea system is in a faulty working state, the fault type is determined based on the conversion efficiency of the catalytic reduction system. In other words, in this embodiment, the gas-driven urea system is detected based on the acquired urea nozzle pressure information and the urea nozzle duty cycle, thereby achieving the separation and anomaly identification of the independent working states of multiple nozzles without relying on multiple pressure sensors or stopping urea injection, thus enabling the determination of whether the gas-driven urea system is faulty. In this embodiment, when the gas-driven urea system is in a faulty working state, the fault type is determined based on the conversion efficiency of the catalytic reduction system in the gas-driven urea system, effectively eliminating misjudgments caused by sensor drift and device aging, thereby improving the accuracy of fault type determination in vehicle urea systems and solving the technical problem of low accuracy in determining fault types in vehicle urea systems.

[0057] The method described in this embodiment will be further described below.

[0058] As an optional embodiment, the method further includes: in response to the gas-driven urea system being in a second operating state, acquiring standard pressure information, wherein the second operating state is used to indicate the state of urea flowing from the urea tank to multiple urea nozzles; and in response to acquiring the standard pressure information, controlling the state of the gas-driven urea system to switch from the second operating state to a first operating state.

[0059] In this embodiment of the application, the second working state described above can be used to indicate the state of urea flowing from the urea tank to multiple urea nozzles.

[0060] Optionally, in response to the air-driven urea system being in its second operating state, under the condition that the urea liquid circuit has completed pre-charging, there is no injection command, and the pressure is stable, at least one urea nozzle is driven to perform one or more injection cycles within a preset duty cycle range. Simultaneously, liquid circuit pressure fluctuations are collected, and based on these pressure fluctuations, standard pressure information matching the current operating state is established. This standard pressure information can also be called a self-learning value. For example, after the vehicle starts and the selective catalytic reduction system has completed preheating but has not yet entered the exhaust gas treatment stage, multiple nozzles are controlled to inject briefly in turn at duty cycles of 10% to 90%, and the corresponding liquid circuit pressure peak, valley, and difference under each duty cycle are recorded as self-learning values.

[0061] Optionally, in response to the acquisition of standard pressure information, after the standard pressure information is collected and determined to be valid, the second working state is terminated, the driving constraint on the nozzle is released, and the injection control logic driven by the vehicle operating conditions and sensor feedback is restored, so that the air-driven urea system enters the first working state of injection, which uses multiple urea nozzles to synchronously inject urea into the gas discharged from the vehicle.

[0062] In this embodiment of the application, the above method can be used to collect the dynamic pressure response of the urea liquid circuit under the ideal state of no fault by a pressure sensor, and automatically generate a usable self-learning value as a benchmark reference for subsequent fault diagnosis, thereby realizing accurate identification and early warning of abnormal states such as urea nozzle blockage and injection volume reduction.

[0063] As an optional embodiment, the standard pressure information includes first standard pressure information, which represents the degree of pressure fluctuation applied to multiple urea nozzles during synchronous urea injection when the gas-driven urea system is in normal operation. Acquiring the standard pressure information in response to the gas-driven urea system being in a second operating state includes: controlling multiple urea nozzles to synchronously inject urea at a preset duty cycle in response to the gas-driven urea system being in the second operating state and the first standard pressure information not existing in the vehicle's electronic control unit; and acquiring the pressure fluctuation within a preset number of injection cycles during urea injection. The system includes: first pressure change information, first minimum pressure value, and first maximum pressure value of the urea nozzle; the first pressure change information indicating the degree of pressure change of the urea nozzle during synchronous urea injection; determining the first pressure difference between the first maximum pressure value and the first minimum pressure value within the same injection cycle; determining the first standard pressure change information of the air-driven urea system based on a preset number of first pressure differences; determining the first standard pressure information based on the first standard pressure change information and the remaining urea level; and acquiring the first standard pressure information from the electronic control unit in response to the first standard pressure information stored therein.

[0064] In this embodiment, the first standard pressure information can be used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the synchronous injection of urea by multiple urea nozzles when the air-driven urea system is in normal condition. The aforementioned electronic control unit can be the vehicle's Electronic Control Unit (ECU). The aforementioned preset duty cycle can be used to represent the proportion of the high-level time in the signal electrically output by the ECU to the urea nozzle during the standard pressure information acquisition phase, for example, 50%. The aforementioned preset quantity can be used to represent the minimum number of samples (e.g., 30 injection cycles) of continuous injection cycles collected by the ECU for statistical pressure fluctuation during the self-learning process. The aforementioned injection cycle can be used to represent a complete working time unit experienced by the urea nozzle from the activation of the opening command to the completion of the closing command. The aforementioned first pressure change information can be used to represent the degree of pressure change of the urea nozzle during the synchronous injection of urea. The aforementioned first minimum pressure value can be used to represent the lowest instantaneous pressure value reached in a single injection cycle due to the instantaneous outflow of urea and the instantaneous release of liquid volume caused by the nozzle opening, which can be represented by Pmin. The first maximum pressure value can be used to represent the pressure peak in the urea liquid path caused by nozzle closure or other reasons within a single injection cycle, and can be represented by Pmax. The aforementioned first pressure difference value can be used to represent the difference between the first maximum pressure value and the first minimum pressure value within a single injection cycle, that is, the difference between Pmax and Pmin within one injection cycle. The aforementioned first standard pressure change information can be used to represent the reference pressure fluctuation formed by statistically aggregating the first pressure differences from multiple injection cycles under ideal operating conditions where the urea nozzle is fault-free, leak-free, and responds normally; this can be represented as EURP_CHECK.

[0065] Optionally, after the vehicle is started and the SCR system has finished warming up, the electronic control unit enters a self-learning mode to confirm that the urea fluid circuit has been pre-charged, there is no leakage, and there are no abnormal alarms. Subsequently, the ECU can send control signals to multiple urea nozzles simultaneously, causing two nozzles to open and close synchronously with a preset duty cycle. During the injection process, the ECU continuously collects the urea fluid circuit pressure signal at a certain sampling frequency (e.g., 100 Hz) through a pressure sensor located near the urea tank outlet. For a continuous preset number of injection cycles, the ECU extracts the pressure waveform in each cycle, records the corresponding minimum pressure value Pmin and maximum pressure value Pmax, and stores the corresponding time series data as the first pressure change information for subsequent analysis.

[0066] Optionally, for each injection cycle, the ECU identifies and extracts local peaks and valleys from the acquired pressure waveform, defining them as the first maximum pressure Pmax and the first minimum pressure Pmin, respectively. Based on the first maximum pressure Pmax and the first minimum pressure Pmin, the first pressure difference within the corresponding cycle can be represented by ΔP, where ΔP = Pmax – Pmin.

[0067] Optionally, the ECU performs statistical processing on the ΔP values ​​corresponding to a preset number (e.g., 30) of injection cycles continuously acquired. Outliers can be removed using a moving average algorithm or median filtering. The weighted average ΔP_avg is calculated, or a confidence interval [ΔP_low, ΔP_high] is constructed. The weighted average ΔP_avg and the confidence interval [ΔP_low, ΔP_high] can be used as the first standard pressure change information.

[0068] For example, the average of the last 10 first pressure differences can also be taken as the urea pressure fluctuation and assigned to the theoretical urea pressure fluctuation EURP_CHECK.

[0069] Optionally, the ECU combines the remaining urea level (which can be obtained from a level sensor or estimated by the cumulative injection volume) with the static pressure correction formula to compensate and correct the first standard pressure change information, so as to eliminate the interference of the system back pressure reduction caused by the drop in liquid level on the pressure fluctuation amplitude; finally, the first standard pressure information is generated and stored in the ECU storage area as a reference value for the subsequent diagnostic stage.

[0070] For example, based on the urea level recorded by EURP_CHECK, the pressure fluctuation y when the level x is 0 can be calculated according to the relationship between pressure fluctuation and level change y=kx+b; and the theoretical urea pressure fluctuation of the remaining level can be calculated according to a 10% urea level gradient and stored in the ECU storage area.

[0071] Optionally, when the vehicle is started again or enters the second working state, the ECU can check whether a valid first standard pressure information has been saved; if it exists and the verification is successful, the first standard pressure information is directly loaded as the current diagnostic benchmark, skipping the relearning process.

[0072] In this embodiment of the application, the pressure fluctuation of the urea liquid path can be converted into quantifiable and calibrable first standard pressure information through the above method, so that the gas-driven urea system has the ability to self-diagnose.

[0073] As an optional embodiment, the standard pressure information includes second standard pressure information. This second standard pressure information represents the degree of pressure fluctuation applied to multiple urea nozzles during alternating urea injection when the gas-driven urea system is in normal operation. Acquiring the standard pressure information in response to the gas-driven urea system being in a second operating state includes: controlling multiple urea nozzles to alternately inject urea at a preset duty cycle in response to the gas-driven urea system being in the second operating state and the absence of second standard pressure information in the vehicle's electronic control unit; and acquiring the pressure fluctuation within a preset number of injection cycles during urea injection. The system includes: second pressure change information, second minimum pressure value, and second maximum pressure value of the urea nozzle; the second pressure change information indicating the degree of pressure change of the urea nozzle during alternating urea injection; determining the second pressure difference between the second maximum and second minimum pressure values ​​within the same injection cycle; determining the second standard pressure change information of the air-driven urea system based on a preset number of second pressure differences; determining the second standard pressure information based on the second standard pressure change information and the remaining urea level; and acquiring the second standard pressure information from the electronic control unit in response to the second standard pressure information stored therein.

[0074] In this application, the aforementioned second standard pressure information can be used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the alternating injection of urea by multiple urea nozzles in a normal gas-driven urea system, including the theoretical urea pressure fluctuation EURP_CHECK_F / EURP_CHECK_R. The aforementioned second pressure change information can be used to represent the degree of pressure change of the urea nozzles during the alternating injection of urea. The aforementioned second minimum pressure value can be used to represent the lowest instantaneous pressure value reached in a single injection cycle when one nozzle is closed, another nozzle completes injection and closes completely, and the urea liquid path experiences no new fluid injection and the elastic rebound of the pipeline tends to stabilize; this can be denoted as Pmin_2. The aforementioned second maximum pressure value can be used to represent the instantaneous pressure peak value caused by the inertia of the liquid flow and the elastic reflection of the pipeline at the instant a nozzle opens and completes urea injection in a single injection cycle; this is denoted as Pmax_2. The aforementioned second pressure difference can be used to represent the difference between the second maximum pressure Pmax_2 and the second minimum pressure Pmin_2 within a single alternating injection cycle, which can be expressed as ΔP_2. The aforementioned second standard pressure change information can be used to represent the pressure fluctuation formed by statistically analyzing ΔP_2 collected from multiple alternating injection cycles under ideal working conditions where the urea nozzle is fault-free, leak-free, and responds normally.

[0075] Optionally, after the vehicle starts and the SCR system completes preheating, the electronic control unit enters the alternating injection self-learning mode. The ECU sequentially sends control signals with opposite phases and the same duty cycle to the two urea nozzles, causing the two nozzles to alternately open and close at a fixed cycle, such as alternating control of the two nozzles to spray in the manner of 50% for the front stage and 0% for the rear stage; or 0% for the front stage and 50% for the rear stage. Each single nozzle injection is considered an alternating injection cycle. The ECU continuously collects the urea liquid circuit pressure signal through a pressure sensor located near the urea tank outlet. For a continuous preset number (e.g., 30) of alternating injection cycles, the ECU identifies the pressure waveform caused by nozzle injection in each cycle and extracts the second pressure change information, the second pressure minimum value Pmin_2, and the second pressure maximum value Pmax_2.

[0076] Optionally, for each alternating injection cycle, the ECU identifies local peaks and valleys from the corresponding pressure waveform and defines them as the maximum and minimum pressures of the corresponding cycle, respectively; then it calculates the second pressure difference for that cycle, which can be obtained by subtracting the minimum pressure from the maximum pressure of the corresponding cycle.

[0077] Optionally, the average of the last 10 second pressure differences can be taken as the urea pressure fluctuation and assigned to the second standard pressure change information.

[0078] Optionally, the ECU combines the real-time urea level height (which can be obtained from a level sensor or dynamically estimated through cumulative injection volume) and corrects EURP_CHECK_F and EURP_CHECK_R based on the static pressure compensation model.

[0079] Optionally, in response to the presence of second standard pressure information in the electronic control unit, obtaining the second standard pressure information from the electronic control unit may include: when the vehicle is started or enters the diagnostic trigger state for the next time, the ECU first queries whether there are valid EURP_CHECK_F and EURP_CHECK_R stored in the non-volatile memory.

[0080] In the embodiments of this application, the above method can realize the autonomous judgment and reuse of the health status of a single nozzle in the dual-nozzle alternating spray mode, which significantly improves the diagnostic accuracy, reduces the false alarm rate, and enhances robustness.

[0081] As an optional embodiment, in response to the gas-driven urea system being in a first operating state, acquiring the pressure information of the urea nozzle includes: in response to the gas-driven urea system being in the first operating state, acquiring the third minimum pressure and the third maximum pressure of the urea nozzle within a preset number of injection cycles, and acquiring the duty cycle; in response to the duty cycle being within a preset duty cycle range, determining the third pressure difference between the third maximum pressure and the third minimum pressure within the same injection cycle; and determining the pressure information based on the third pressure difference.

[0082] In this embodiment, the aforementioned third minimum pressure value can be used to represent the lowest instantaneous pressure value reached within a single injection cycle when the urea nozzle is in the open state and injection is completed, due to the instantaneous outflow of urea causing a sudden increase in the liquid path volume and an instantaneous pressure release. This can be represented by Pmin_3. The aforementioned third maximum pressure value can be used to represent the instantaneous pressure peak value caused by the inertia of the urea fluid and the rebound effect of the elastic material in the liquid path when the urea nozzle suddenly closes from the open state within a single injection cycle. This can be represented by Pmax_3. The aforementioned preset duty cycle range can be the effective injection range commonly used by the urea nozzle under normal operating conditions, such as 25% to 75%. The aforementioned third pressure difference can be used to represent the dynamic fluctuation amplitude of the urea liquid path pressure caused by the opening and closing action of the nozzle within a single effective injection cycle. This can be represented by ΔP_3.

[0083] Optionally, in response to the air-driven urea system being in its first operating state, the ECU continuously monitors the control commands and real-time pressure signals of the urea nozzle; the ECU collects pressure data from a single pressure sensor located near the urea tank outlet and simultaneously records the duty cycle control commands for each injection cycle; for a continuously preset number of injection cycles (e.g., 30), the ECU can extract the third minimum pressure value Pmin_3, the third maximum pressure value Pmax_3, and the duty cycle of the current injection cycle cycle by cycle.

[0084] Optionally, the ECU determines whether the duty cycle of the current injection cycle falls within a preset duty cycle range, such as [25%, 75%]. If so, it calculates the third pressure difference value ΔP_3 for the corresponding cycle, where ΔP_3 = Pmax_3 – Pmin_3.

[0085] Optionally, based on the aforementioned third pressure difference, the ECU performs statistical processing on the ΔP_3 samples. For example, it uses a moving average algorithm to dynamically calculate the arithmetic mean of the most recent N (e.g., 10) valid ΔP_3 samples, which serves as the pressure information at the current moment and can be represented by Paver.

[0086] In the embodiments of this application, the above method can achieve high-precision, low-false-alarm, and online early warning of urea nozzle performance degradation.

[0087] As an optional embodiment, the standard pressure information includes first standard pressure information, which is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the synchronous injection of urea by multiple urea nozzles when the gas-driven urea system is in a normal state. Based on the pressure information, the standard pressure information of the gas-driven urea system, and the duty cycle of the urea nozzles, the gas-driven urea system is detected to obtain a detection result, including: in response to the difference between the pressure information and the first standard pressure information being less than a first threshold, the detection result is determined to be that the gas-driven urea system is in a fault state.

[0088] In this embodiment, the first threshold can be used to represent the maximum allowable normal fluctuation deviation between the pressure information (Paver) and the first standard pressure information (P_std1) when the gas-driven urea system is in a healthy state. For example, if P_std1 = 4.0 bar, the first threshold can be set to 0.4 bar to 0.6 bar.

[0089] Optionally, during vehicle operation, the ECU continuously calculates the current pressure information Paver and compares it with the first standard pressure information P_std1 stored in the ECU's storage area, and calculates the corresponding difference; it determines that the corresponding difference is greater than a first threshold and that the difference remains greater than the first threshold for at least two complete driving cycles; it confirms that the injection cycles used to calculate Paver meet the preset duty cycle; it confirms that the ECU does not report other faults such as sensor open circuit or nozzle drive circuit failure; when the above conditions are met simultaneously, the ECU can determine that there is a fault in the air-driven urea system and can output a blockage warning status.

[0090] In the embodiments of this application, the above method can be used to achieve highly sensitive and reliable detection of early minor blockage of urea nozzles through diagnostic logic such as the continuous exceeding of the difference between Paver and P_std1.

[0091] As an optional embodiment, the standard pressure information includes second standard pressure information, which is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the alternating injection of urea by multiple urea nozzles in a normal gas-driven urea system. In response to a detection result indicating that the gas-driven urea system is in a fault state, the fault type is determined based on the conversion efficiency of the catalytic reduction system, including:

[0092] In response to the detection result indicating a fault in the gas-driven urea system, multiple urea nozzles are controlled to alternately inject urea at a preset duty cycle. During urea injection, the minimum and maximum fourth pressure values ​​of the urea nozzles are acquired within a preset number of injection cycles. The fourth pressure difference between the maximum and minimum fourth pressure values ​​within the same injection cycle is determined. Based on the fourth pressure difference, pressure sub-information of the urea nozzles is determined, where the pressure sub-information represents the degree of pressure fluctuation applied to the multiple urea nozzles during alternating urea injection. In response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, a correction operation is performed on the gas-driven urea system and the catalytic reduction system. The conversion efficiency of the catalytic reduction system after the correction operation is acquired. Based on the conversion efficiency, the fault type is determined.

[0093] In this embodiment, the aforementioned fourth minimum pressure value can be used to represent the instantaneous lowest pressure value recorded when the total pressure of the gas-driven urea system enters a periodic trough during the alternating urea nozzle injection mode, and can be represented by Pmin_4. The fourth maximum pressure value can be used to represent the instantaneous highest pressure value formed on the corresponding liquid path branch of a nozzle during the alternating urea nozzle injection mode, due to fluid inertia and the rebound of the elastic material in the liquid path at the moment a nozzle is closed, and can be represented by Pmax_4. The aforementioned fourth pressure difference can be used to represent the difference between the fourth maximum pressure value and the fourth minimum pressure value within the same injection cycle, and can be represented by ΔP_4. The aforementioned pressure sub-information can be used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the alternating urea injection process. The aforementioned correction operation can be used to represent a series of coordinated compensation and control strategy correction actions automatically executed by the ECU after determining that there is a nozzle abnormality in order to restore the efficiency of the catalytic reduction system.

[0094] Optionally, after receiving a "blockage warning" signal, the ECU can stop the regular synchronous injection command to the two urea nozzles; control the two nozzles to alternately inject with a 50% duty cycle and a 180° phase difference; continuously collect signals from a single pressure sensor, which can cover a certain number (e.g., 10) complete alternating injection cycles; in each injection cycle, the ECU identifies and records the fourth pressure minimum value Pmin_4 and the fourth pressure maximum value Pmax_4.

[0095] Optionally, for each alternating injection cycle, the ECU can obtain the corresponding fourth pressure difference value by subtracting the fourth pressure maximum value from the fourth pressure minimum value.

[0096] Optionally, the ECU classifies the effective ΔP_4 into pre-stage nozzles and post-stage nozzles, performs moving average processing on the ΔP_4 sequences of the two channels respectively, and calculates the corresponding pressure sub-information.

[0097] Optionally, if the difference between the pressure sub-information and the second standard pressure information is less than the first threshold, the ECU can determine that it is a single nozzle blockage fault. If the front nozzle is abnormal, the injection duty cycle of the rear nozzle can be increased from 50% to 65%~80% to compensate for the total urea flow loss. Alternatively, the injection frequency of the normal nozzle can be increased while meeting the first substance emission requirements.

[0098] Optionally, the correction operation performed on the catalytic reduction system in response to the difference between the pressure sub-information and the second standard pressure information being less than the first threshold may include: resetting the nitrogen oxide conversion target value of the SCR control module according to the compensated urea injection amount to avoid over-injection; or ensuring that the SCR catalyst temperature is maintained at ≥200 degrees Celsius by increasing the engine exhaust temperature or activating the electric heater to maintain activity.

[0099] Optionally, the ECU can collect the inlet and outlet concentrations of the first substance in real time using sensors installed at the inlet and outlet of the SCR catalyst; during the stable operation phase after the correction operation, the ECU can improve the conversion efficiency calculated by the conversion ECU.

[0100] Optionally, the ECU performs fault type classification based on the comparison between conversion efficiency and preset threshold.

[0101] In the embodiments of this application, the above method can achieve early warning at the system level by attenuating pressure fluctuations under synchronous injection, and accurately locate the fault by using the independent pressure difference between the front and rear nozzles, thus realizing decision-making from fault perception to fault attribution.

[0102] As an optional embodiment, the fault type includes urea nozzle failure. Based on conversion efficiency, the fault type is determined, including: in response to the conversion efficiency being less than a conversion efficiency threshold, determining the fault type as urea nozzle failure.

[0103] In the embodiments of this application, the above-mentioned conversion efficiency threshold can be used to represent the lowest acceptable first substance conversion efficiency benchmark value that the catalytic reduction system can stably achieve when the SCR system is in a healthy working state (i.e., the urea nozzle is not blocked, the catalyst activity is normal, and the exhaust temperature is suitable).

[0104] Optionally, the corresponding sensor signals are collected through the sensors at the SCR inlet and outlet; the rolling average conversion efficiency is calculated; if the conversion efficiency is less than the above conversion efficiency threshold, the ECU can determine that the current decrease in the conversion efficiency of the first substance is due to insufficient urea injection volume; it can try to compensate by increasing the injection volume of another nozzle; if the conversion efficiency still does not recover to above the threshold, the fault type can be determined to be urea nozzle fault.

[0105] In this embodiment, the above method can be used to construct an intelligent diagnostic paradigm for urea nozzle malfunctions, with emission results as the final judgment criterion. This achieves highly sensitive and reliable detection of urea nozzle malfunctions.

[0106] As an optional embodiment, the gas-driven urea system includes a urea tank. In response to the difference between pressure sub-information and second standard pressure information being less than a first threshold, a correction operation is performed on the gas-driven urea system, including: increasing the pressure in the urea tank to a preset pressure in response to the difference between the pressure sub-information and the second standard pressure information being less than the first threshold; re-determining the difference between the pressure sub-information and the second standard pressure information; and determining that the correction operation on the gas-driven urea system has been completed in response to the re-determined difference between the pressure sub-information and the second standard pressure information being less than the second threshold.

[0107] In this embodiment, the urea tank can be a storage container for storing urea aqueous solution. The preset pressure can be used to represent a high pressure, higher than the normal operating pressure, actively applied to the urea tank's pressure chamber. The second threshold can be used to represent the boundary value for determining whether the pressure sub-information has recovered to a healthy level after a correction operation and re-collection of the pressure sub-information.

[0108] Optionally, in response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, the current alternating injection diagnosis is interrupted; the exhaust valve is closed to ensure the urea tank pressure chamber is sealed; the compressed air intake solenoid valve is opened to slowly increase the air pressure in the urea tank to the preset pressure; the preset pressure is maintained to allow the urea liquid to continuously impact the deposits inside the nozzle; the intake valve is closed, the exhaust valve is opened, and the tank pressure is quickly released back to the normal operating pressure and the correction event is recorded.

[0109] Optionally, the two nozzles are controlled to continue spraying alternately with a 50% duty cycle and a phase difference of 180°; a certain number (e.g., 10) of complete spray cycles of Pmin_4 and Pmax_4 are collected; the ΔP_4 sequence of the front / back nozzles is recalculated and a moving average is performed respectively to obtain the redefined pressure sub-information.

[0110] Optionally, when the redefined pressure information is less than the second threshold, the ECU can determine that the correction operation was successful.

[0111] In this embodiment of the application, the above method can automatically clear nozzle blockages and perform a complete correction on the gas-driven urea system, which can significantly improve system reliability, reduce after-sales costs, and extend the maintenance cycle.

[0112] As an optional embodiment, performing a correction operation on the catalytic reduction system includes: adjusting a target ratio in the catalytic reduction system during the correction operation to obtain an adjusted target ratio, wherein the target ratio represents the proportion by which the catalytic reduction system reduces the first substance.

[0113] In this application, the aforementioned target ratio can be used to represent the dynamically adjustable theoretical conversion target value of the first substance set by the catalytic reduction system under the current urea supply conditions to maintain the first substance emission compliance.

[0114] Optionally, after receiving a urea nozzle blockage warning, the ECU can reduce the target ratio; perform nozzle compensation (e.g., increase the duty cycle of the normally operating nozzle to 65%~80%) to calculate the current conversion efficiency; if the current conversion efficiency is greater than the target ratio, it can try to slightly increase the target ratio; otherwise, it can maintain the target ratio or further reduce it.

[0115] In this embodiment, the above method can acquire pressure information from multiple urea nozzles in response to the gas-driven urea system being in a first operating state; based on the pressure information, the standard pressure information of the urea nozzles, and the duty cycle of the urea nozzles, the gas-driven urea system is detected to obtain a detection result; in response to the detection result indicating that the gas-driven urea system is in a faulty operating state, the fault type is determined based on the conversion efficiency of the catalytic reduction system. In other words, in this embodiment, the gas-driven urea system is detected based on the acquired urea nozzle pressure information and the urea nozzle duty cycle to determine whether the gas-driven urea system is in a faulty operating state. This embodiment determines the fault type based on the conversion efficiency of the catalytic reduction system in the gas-driven urea system when it is in a faulty operating state, thereby improving the accuracy of fault type determination in vehicle urea systems and solving the technical problem of low accuracy in fault type determination in vehicle urea systems.

[0116] The technical solutions of the embodiments of this application will be illustrated below with reference to preferred embodiments.

[0117] Currently, in related technologies, SCR systems typically use multiple sensors to monitor the urea injection process to ensure proper nozzle operation and precise control of the urea injection volume. Each urea nozzle is often equipped with at least one pressure sensor to detect pressure changes before and after the nozzle, thereby determining whether the nozzle is clogged or malfunctioning.

[0118] In this embodiment, the dual-stage nozzles employ synchronous injection, enabling hydraulic pressure to replace pneumatic pressure (also using the maximum value envelope). The pressure sensor is positioned close to the urea tank, allowing simultaneous diagnosis of both urea nozzles. Diagnostic warnings are triggered by changes in urea pressure fluctuations, resulting in injection at a 50% duty cycle. The two urea nozzles are diagnosed alternately (one at a time). The nozzle blockage is determined by comparing the pressure fluctuation change value with the self-learning value. Nozzle diagnosis is performed by adjusting the two nozzles to asynchronous injection.

[0119] In this embodiment, during normal vehicle operation, a blockage warning is first issued by dynamically recording the maximum and minimum hydraulic pressure values ​​Pmax and Pmin. A moving average algorithm can be used to dynamically record the maximum and minimum hydraulic pressure values ​​Pmax and Pmin over 30 seconds. In each driving cycle, when the urea system is operating normally, if the urea nozzle control duty cycle is within the range of 25% to 5% in the 30 seconds of data recorded in the data storage, the window is considered valid. The difference between Pmax and Pmin in one injection cycle is calculated, and the average difference over the last 10 seconds is recorded as Paver. A data storage device is set up to record 10 Paver data points, which can be dynamically updated over time. The aforementioned Paver data can be carried over to the next driving cycle.

[0120] Optionally, the difference between Paver and the self-learning value is dynamically calculated. When the difference is less than the first threshold, a urea nozzle blockage warning is issued, triggering the urea nozzle blockage diagnosis function.

[0121] Optionally, the urea nozzle blockage diagnostic function is activated, and instead of responding to the ECU control duty cycle, the two nozzles are alternately sprayed at a 50% duty cycle to determine the difference between the pressure fluctuation value and the self-learned value, thereby confirming the fault.

[0122] In this embodiment of the application, when the urea nozzle diagnosis is triggered, the two nozzles are adjusted to asynchronous injection and self-learning is performed in single pressure mode; when the difference between the maximum urea pressure and the median value and the difference between the self-learned value are greater than the threshold, the distal nozzle is determined to be blocked; when the difference between the minimum urea pressure and the median value and the difference between the self-learned value are greater than the threshold, the distal nozzle is determined to be blocked.

[0123] In this embodiment, the dual-stage nozzle synchronous injection technology combined with the layout of a single pressure sensor enables the system to monitor the working status of both nozzles at a lower cost, reducing the cost increase caused by adding sensors. The diagnostic early warning mechanism that compares urea pressure fluctuation values ​​with self-learning values ​​can identify potential nozzle blockage risks in advance, ensuring that the system can adjust itself in a timely manner or remind maintenance, thereby improving the reliability and service life of the entire urea injection system. The flexible design of the abnormal diagnosis strategy, including self-learning diagnosis in alternating injection with a 50% duty cycle and asynchronous injection modes, enhances adaptability to different operating conditions and ensures the accuracy and comprehensiveness of the diagnosis.

[0124] The embodiments of this application will be further described below.

[0125] Figure 2 This is a graph illustrating a diagnostic method for urea nozzle malfunction according to an embodiment of this application. Figure 2 As shown, the graph for diagnosing urea nozzle malfunction includes a horizontal axis (x) representing time and a vertical axis representing pressure. HCP2_VAR_w_[kPa] represents the raw value acquired by the urea liquid path pressure sensor; EURP_VAR_FILT_w_[kPa] represents the real-time pressure signal of the urea solution.

[0126] Figure 3 This is a schematic diagram of a urea nozzle abnormality diagnosis system according to an embodiment of this application. Figure 3 As shown, the urea nozzle malfunction diagnostic system includes an air source, pressure gauge, intake solenoid valve, exhaust solenoid valve, CANape, ECU, urea tank, urea filter, urea nozzle, and measuring cup. The system also includes P1, P2, and P3, where P1 represents the tank pressure (air pressure), P2 represents the urea filter pressure, and P3 represents the nozzle pressure.

[0127] Figure 4 This is a flowchart illustrating the pressure build-up process of a urea system according to an embodiment of this application. For example... Figure 4 As shown, the pressure build-up process for the urea system includes the following steps.

[0128] Step S402, urea system pressure build-up start: open the intake valve, close the exhaust valve, charge the system to the target pressure, and assign the value collected by the urea pressure sensor to the urea tank pressure to determine whether the target pressure has been achieved.

[0129] Optionally, the control unit opens the intake valve, closes the exhaust valve, and starts the air pump to charge the urea liquid circuit system to a preset target pressure; at the same time, it collects the gas circuit pressure sensor signal (which can be represented by P_gas) and the liquid circuit pressure sensor signal (which can be represented by P_liquid) in real time; when the liquid circuit pressure reaches the target pressure and the stabilization time is ≥2 seconds, the pressure is determined to be successful.

[0130] Step S404: Pressure build-up successful, injection ready. Set timer to record urea system operating time, which can be carried over to the next driving cycle.

[0131] Optionally, the urea system enters the injection standby state, allowing the execution of urea injection commands; at the same time, the steady-state average values ​​of P_gas and P_liquid at the current moment are recorded as the initial reference for subsequent sensor self-correction. The above reference value is only used for one initial calibration and is not stored, updated, or used in subsequent diagnostics.

[0132] Step S406, new car rolls off the production line (determine if there is a self-learning value in the ECU).

[0133] Optionally, if the flag is set, it indicates that the ECU is not a new vehicle (e.g., ECU replacement, repair return); if the flag is not set, it indicates that the vehicle is a brand new off-line vehicle. Perform a single initial sensor correction procedure, set the flag to "set", and lock it.

[0134] Optionally, if there is a self-learning value, step S408 can be executed, i.e., as follows: Figure 5 The urea system shown here has a self-learning capability. If there is no self-learning value, then step S410 can be executed, i.e., as shown... Figure 7 The image shows urea injection / pressure replenishment.

[0135] Step S408, urea system self-learning.

[0136] Optionally, perform as follows Figure 5 The urea pressure sensor shown is self-learning.

[0137] Step S410, urea injection / pressure replenishment.

[0138] Optionally, perform as follows Figure 7 The image shows urea injection / pressure replenishment.

[0139] Figure 5 This is a flowchart illustrating a self-learning process for a urea system according to an embodiment of this application. For example... Figure 5 As shown, the self-learning process of this urea system includes the following steps.

[0140] Step S502: Control the two nozzles to spray at a 50% duty cycle (synchronous spraying).

[0141] Optionally, two nozzles (proximal and distal) are simultaneously controlled to perform asynchronous injection with a 50% duty cycle and an injection interval of 0.5 seconds; the injection duration is 15 seconds (covering 30 complete injection cycles, each cycle being 1 second); the urea level is maintained within 50% ± 10% during injection (through feedback from an oil level sensor to ensure consistent operating conditions); the injection strategy is not adjusted with changes in liquid level, and liquid level data is not collected for modeling.

[0142] Step S504: Monitor and record the liquid pressure change of the urea nozzle in one injection cycle in real time. The minimum liquid pressure is recorded as Pmin and the maximum liquid pressure is recorded as Pmax.

[0143] Optionally, the pressure sampling frequency is ≥100 Hz to ensure that the transient peaks and valleys of pressure within each injection cycle are captured; within 15 seconds (30 cycles), Pmin_1~Pmin_30 and Pmax_1~Pmax_30 are recorded cycle by cycle; extreme value filtering is performed on each set of data: the first 2 sampling points (pressure build-up stage) and the last 2 sampling points (pressure decay stage) in each cycle are removed, and only the middle stable segment (about 60% of the cycle length) is retained for calculating Pmin and Pmax.

[0144] Step S506: Use the moving average algorithm to record the maximum value Pmax, minimum value Pmin, and median value of the liquid circuit pressure within 30 injection cycles. Calculate the difference between Pmax and Pmin within one injection cycle and the median value, and take the average of the last 10 differences as the urea pressure fluctuation, which is then assigned to the theoretical urea pressure fluctuation EURP_CHECK.

[0145] Optionally, the median value for each injection cycle is defined as the arithmetic mean of Pmax and Pmin within the corresponding cycle; for each injection cycle, the corresponding pressure fluctuation amplitude is calculated; the larger of the difference between Pmax and the median value and the difference between the median value and Pmin is taken as the actual pressure fluctuation value for that cycle; for the pressure fluctuation amplitude of 30 cycles, only the pressure fluctuation amplitude of the last 10 cycles is taken to calculate EURP_CHECK.

[0146] Step S508: Based on the urea level recorded by EURP_CHECK, calculate the pressure fluctuation y when the level x is 0, i.e. the value of b, according to the relationship between pressure fluctuation and level change y=kx+b; and calculate the theoretical urea pressure fluctuation of the remaining level according to a 10% urea level gradient, and place it in the ECU storage area.

[0147] Step S510: Determine whether data storage is complete.

[0148] Optionally, check whether Pmax and P_min have been successfully written to the storage area; if it fails, retry once; if it still fails, trigger the "diagnostic baseline establishment failure" fault code and disable the urea system.

[0149] Optionally, if so, step S512 is executed; otherwise, step S502 is executed.

[0150] Step S512, urea injection / pressure replenishment.

[0151] Optionally, perform as follows Figure 7 Urea injection / pressurization shown

[0152] Figure 6 This is a flowchart illustrating the monitoring and recording of a urea nozzle according to an embodiment of this application. For example... Figure 6 As shown, monitoring and recording the urea nozzle involves the following steps.

[0153] Step S602: Monitor and record the liquid pressure change of the urea nozzle in one injection cycle in real time. The minimum liquid pressure is recorded as Pmin and the maximum liquid pressure is recorded as Pmax.

[0154] Optionally, the pressure sensor uses a sampling frequency of 100Hz to ensure that no less than 50 data points are collected in each injection cycle (typical cycle 0.5~2s); the raw pressure signal is processed by median filtering and five-point moving average to eliminate high-frequency noise interference (such as pump pulsation and sensor jitter); in each injection cycle, only the injection start-up stable segment is retained (i.e., the first 0.1s pressure build-up stage and the last 0.1s pressure relief stage are removed), and the effective data range accounts for more than 70% of the cycle, improving the representativeness of the data; Pmax and Pmin are extracted.

[0155] Step S604: Use the moving average algorithm to record the maximum value Pmax and minimum value Pmin of the liquid circuit pressure within 30 injection cycles. Calculate the difference between Pmax and Pmin within one injection cycle, and take the average of the last 10 differences as the urea pressure fluctuation, assigning it to the theoretical urea pressure fluctuation EURP_CHECK_F / EURP_CHECK_R.

[0156] Step S606: Based on the urea level recorded by EURP_CHECK_F / EURP_CHECK_R, calculate the pressure fluctuation y when the level x is 0, i.e. the value of b, according to the relationship between pressure fluctuation and level change y=kx+b; and calculate the theoretical urea pressure fluctuation of the remaining level according to a 10% urea level gradient, and place it in the ECU storage area.

[0157] Step S608: Determine whether data storage is complete.

[0158] Optionally, if so, then step S612 is performed, i.e., as follows: Figure 7 If the urea injection / pressure replenishment is not indicated, then proceed to step S604.

[0159] Step S612, urea injection / pressure replenishment.

[0160] Optionally, perform as follows Figure 7 The image shows urea injection / pressure replenishment.

[0161] Figure 7 This is a flowchart of a urea injection / pressure replenishment process according to an embodiment of this application. Figure 7 As shown, urea injection / pressure replenishment includes the following steps.

[0162] Step S702, urea injection / pressure replenishment.

[0163] Optionally, the system executes urea injection according to ECU instructions, or initiates an automatic pressure replenishment program when the liquid circuit pressure is lower than the set lower limit: controlling the intake valve to open and the exhaust valve to close, and starting the air pump to pressurize the liquid circuit; real-time acquisition of: gas circuit pressure P_gas; liquid circuit pressure P_liquid.

[0164] Step S704: Is the power off for the entire vehicle?

[0165] Optionally, the vehicle's power status can be detected; if power is lost, all injection and monitoring will stop, the urea system will enter hibernation, and all fixed parameters will be retained.

[0166] Step S706, passive monitoring function of urea system.

[0167] Optionally, perform as follows Figure 8 The urea filter element clogging monitoring function is shown.

[0168] Optionally, if yes, stop; otherwise, proceed to step S702.

[0169] Figure 8 This is a flowchart of a passive monitoring function for a urea system according to an embodiment of this application.

[0170] like Figure 8 As shown, the passive monitoring function of the urea system includes the following steps.

[0171] Step S802: Set up a data storage device and use a moving average algorithm to dynamically record the maximum value Pmax, minimum value Pmin, and median value of the hydraulic pressure within 30 injection cycles.

[0172] Optionally, the following parameters are collected at a frequency of 1 Hz (every 1 second): gas pressure P_gas and liquid pressure P_liquid; the current instantaneous average system pressure is calculated as: Pmid = (P_gas + P_liquid) / 2; and the current gas-liquid pressure difference is calculated as: ΔP_filter = |P_gas – Pmid|.

[0173] Step S804: Determine whether the urea nozzle control duty cycle is within the range of 25%-75%.

[0174] Optionally, if yes, then step S806 is executed; otherwise, step S802 is executed.

[0175] Step S806: Calculate the difference between Pmax and the median value Pmin within one injection cycle, and take the average of the differences over the last 10 cycles as Paver. Set up a data storage device to record 10 Paver-max and 10 Paver-min data points, which can be dynamically updated over time. This data can be carried over to the next driving cycle.

[0176] Step S808: Is the difference greater than the first threshold?

[0177] Optionally, if so, then step S810 is performed, that is, as follows Figure 9 The urea nozzle blockage diagnosis function is shown; otherwise, step S806 can be executed.

[0178] Step S810, urea nozzle blockage diagnosis function.

[0179] Optionally, perform as follows Figure 9 The urea nozzle blockage diagnosis function is shown.

[0180] Figure 9 This is a flowchart illustrating a urea nozzle blockage diagnosis function according to an embodiment of this application. Figure 9 As shown, the urea nozzle blockage diagnostic function may include the following steps.

[0181] Step S902: Alternately control the two nozzles to spray at a 50% duty cycle (pre-stage 50%, post-stage 0%; pre-stage 0%, post-stage 50%).

[0182] Optionally, the ECU performs alternating injection with a 180° phase difference in a diagnostic cycle of 1 second: the first 0.5 seconds include only opening the front nozzle (proximal nozzle), duty cycle 50% → injection for 0.5 seconds, and closing for 0.5 seconds; the next 0.5 seconds include only opening the rear nozzle (far nozzle), duty cycle 50% → injection for 0.5 seconds, and closing for 0.5 seconds.

[0183] Step S904: Monitor and record the liquid pressure change of the urea nozzle in one injection cycle in real time. The minimum liquid pressure is recorded as Pmin and the maximum liquid pressure is recorded as Pmax.

[0184] Optionally, the pressure sensor collects data at a sampling frequency of 100 Hz to ensure that at least 50 data points are collected within each 0.5-second injection segment; the raw signal is subjected to median filtering and five-point moving average to eliminate high-frequency noise such as pump pulsation and electromagnetic interference; within each injection segment (0.5s before / after), only the middle 70% time period is retained (removing the pressure build-up in the first 0.05s and the pressure relief in the last 0.05s) to ensure that the data reflects a stable injection state.

[0185] Step S906: Using a moving average algorithm, record the maximum and minimum pressure values ​​Pmax and Pmin of the liquid path within 30 injection cycles. Calculate the difference between Pmax and Pmin within one injection cycle, and take the average of the last 10 differences as the urea pressure fluctuation. Then, calculate the difference between this average and the theoretical urea pressure fluctuation EURP_CHECK_F / EURP_CHECK_R, and determine the magnitude of the difference. Specifically, EURP_CHECK_F represents the theoretical urea pressure fluctuation of the upstream nozzle at each liquid level, and EURP_CHECK_R represents the theoretical urea pressure fluctuation of the downstream nozzle.

[0186] Step S908: Is the difference less than the first threshold?

[0187] Optionally, if so, then step S910 is performed, i.e. Figure 10 The urea system pre-correction function is shown. If not, proceed to step 906.

[0188] Step S910, urea system pre-correction function.

[0189] Optionally, perform as follows Figure 10 The urea system pre-correction function is shown. For example... Figure 10 As shown, the passive monitoring function of the urea system may include the following steps.

[0190] Step S1002: Open the air intake valve to increase the pressure in the urea tank by 1 bar.

[0191] Optionally, the ECU controls the intake valve to open and applies additional air pressure to the urea liquid circuit system through an air pump, so that the pressure in the urea tank rises steadily by 1 bar within 3 to 5 seconds, artificially creating pressure disturbance to activate the system response characteristics.

[0192] Step S1004: Calculate the difference between the urea pressure fluctuation and the theoretical urea pressure fluctuation again.

[0193] Optionally, after the pressure increase is completed, the ECU continues to collect the hydraulic pressure fluctuation data of the current cycle, calculates the current actual pressure fluctuation amplitude, and calculates the difference with the pre-stored theoretical urea pressure fluctuation EURP_CHECK.

[0194] Step S1006: Is the difference greater than the second threshold?

[0195] Optionally, if ΔP_diff > the second threshold (e.g., 1.0 bar), then it is determined that the system has abnormal resistance or blockage risk, and step S1008 is executed, i.e. Figure 11 The selective catalytic reduction system shown has a nitrogen and oxygen feedback correction function; if ΔP_diff ≤ the second threshold, the system is determined to be in normal condition, and step S1010 is executed, i.e. Figure 8 The passive monitoring function of the urea system is shown.

[0196] Step S1008, SCR system post-nitrogen oxygen feedback correction function.

[0197] Optionally, the real-time measurement value of NOx concentration at the SCR outlet is obtained; the deviation between the theoretical NOx conversion efficiency and the actual measurement value is compared. If the deviation continues to exceed the set value, the abnormal urea pressure fluctuation result is combined to determine that the filter element is severely clogged or the nozzle is malfunctioning, and a high-priority fault code (DTC) is generated, triggering the instrument alarm and torque limiting protection mechanism.

[0198] Step S1010, passive monitoring function of urea system.

[0199] Optionally, perform as follows Figure 8 The passive monitoring function of the urea system is shown.

[0200] Figure 11 This is a flowchart illustrating the nitrogen and oxygen feedback correction function after selective reduction of a system according to an embodiment of this application, as shown below. Figure 11 As shown, the nitrogen and oxygen feedback correction function after the selective catalytic reduction system may include the following steps.

[0201] Step S1102, adjust the upper limit of the allowable ammonia-nitrogen ratio to 1.5~2 (classified according to the degree below the threshold).

[0202] Optionally, the ECU can determine whether the exhaust gas reduction efficiency is insufficient based on the degree of deviation between the current SCR outlet NOx concentration and the theoretical model, and accordingly make graded corrections to the upper limit of the allowable ammonia-nitrogen ratio.

[0203] Step S1104: Confirm whether the SCR system conversion efficiency is lower than the threshold.

[0204] Optionally, the ECU calculates the real-time conversion efficiency of the current SCR system; if the conversion efficiency is not lower than a preset threshold (e.g., 75%), then step S1108 is executed.

[0205] If the conversion efficiency is below the threshold, then stop.

[0206] Step S1106, passive monitoring function of urea system.

[0207] Optionally, execute as follows Figure 8 The passive monitoring function of the urea system is shown.

[0208] In this embodiment, the above method can acquire pressure information from multiple urea nozzles in response to the gas-driven urea system being in a first operating state; based on the pressure information, the standard pressure information of the urea nozzles, and the duty cycle of the urea nozzles, the gas-driven urea system is detected to obtain a detection result; in response to the detection result indicating that the gas-driven urea system is in a faulty operating state, the fault type is determined based on the conversion efficiency of the catalytic reduction system. In other words, in this embodiment, the gas-driven urea system is detected based on the acquired urea nozzle pressure information and the urea nozzle duty cycle to determine whether the gas-driven urea system is in a faulty operating state. This embodiment determines the fault type based on the conversion efficiency of the catalytic reduction system in the gas-driven urea system when it is in a faulty operating state, thereby improving the accuracy of fault type determination in vehicle urea systems and solving the technical problem of low accuracy in fault type determination in vehicle urea systems.

[0209] Figure 12 This is a schematic diagram of a fault type determination device for a gas-driven urea system in a vehicle according to an embodiment of this application. As shown in Figure 12, the fault type determination device 1200 for a gas-driven urea system in a vehicle includes an acquisition unit 1202, which is used to acquire pressure information of multiple urea nozzles in response to the gas-driven urea system being in a first operating state. The first operating state is an injection state in which urea is injected into the gas discharged from the vehicle synchronously using multiple urea nozzles. The pressure information is used to indicate the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea.

[0210] The detection unit 1204 is used to detect the air-driven urea system based on pressure information, standard pressure information of the urea nozzle, and duty cycle of the urea nozzle, and obtain the detection results. The standard pressure information is used to indicate the degree of pressure fluctuation applied to the urea nozzle during the urea injection process when the air-driven urea system is in normal working condition.

[0211] The determining unit 1206 is used to determine the fault type of the fault state based on the conversion efficiency of the catalytic reduction system in response to the detection result indicating that the gas-driven urea system is in a faulty working state. The catalytic reduction system is used to convert a first substance in the gas into a second substance using urea. The degree of pollution of the gas by the first substance is greater than the degree of pollution of the gas by the second substance.

[0212] In this embodiment, the acquisition unit, in response to the gas-driven urea system being in a first operating state, acquires pressure information from multiple urea nozzles. The first operating state is a state where multiple urea nozzles simultaneously inject urea into the gas emitted by the vehicle. The pressure information indicates the degree of pressure fluctuation applied to the multiple urea nozzles during synchronous urea injection. The detection unit, based on the pressure information, the standard pressure information of the urea nozzles, and the duty cycle of the urea nozzles, detects the gas-driven urea system and obtains a detection result. The standard pressure information indicates the degree of pressure fluctuation applied to the urea nozzles during urea injection when the gas-driven urea system is in normal operating condition. The determination unit, in response to the detection result indicating that the gas-driven urea system is in a faulty operating state, determines the fault type based on the conversion efficiency of the catalytic reduction system. The catalytic reduction system uses urea to convert a first substance in the gas into a second substance. The first substance's contamination level is greater than that of the second substance, thereby improving the accuracy of fault type determination in the vehicle's urea system and solving the technical problem of low accuracy in fault type determination in the vehicle's urea system.

[0213] According to another aspect of the embodiments of this application, a vehicle is also provided. The vehicle may include a memory and a processor. The memory stores an executable program. The processor can be used to run the program, wherein, when the program runs, it executes the fault type determination method for the gas-driven urea system described in the embodiments of this application.

[0214] According to another aspect of the embodiments of this application, an electronic device is also provided, the electronic device including a memory storing an executable program; and a processor for running the program, wherein the program executes the fault type determination method of the gas-driven urea system described in the embodiments of this application.

[0215] According to embodiments of this application, a computer-readable storage medium is also provided, the storage medium including a stored program, wherein the program executes the method for determining the duration of function retention of a dryer canister in a vehicle as described in the above embodiments. According to embodiments of this application, a processor is also provided for running a program, wherein the program, when running, executes the method for determining the duration of function retention of a dryer canister in a vehicle as described in the above embodiments. According to another aspect of embodiments of this application, a vehicle is also provided. The vehicle may include a memory and a processor. The memory stores an executable program. The processor may be used to run the program, wherein the program, when running, executes the method for determining the fault type of a gas-driven urea system as described in the above embodiments of this application.

[0216] Embodiments of this application also provide a computer program product. Optionally, in this embodiment, the computer program product may include a computer program that, when executed by a processor, implements the fault type determination method for the gas-driven urea system described in the embodiments of this application.

[0217] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0218] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units.

[0219] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, ROM, RAM, portable hard drives, magnetic disks, or optical disks.

[0220] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for determining the fault type of a gas-driven urea system in a vehicle, characterized in that, The gas-driven urea system includes multiple urea nozzles and a catalytic reduction system, and the method includes: In response to the gas-driven urea system being in a first operating state, pressure information of multiple urea nozzles is acquired, wherein the first operating state is an injection state in which urea is injected into the gas discharged from the vehicle synchronously using multiple urea nozzles, and the pressure information is used to indicate the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea. Based on the pressure information, the standard pressure information of the urea nozzle, and the duty cycle of the urea nozzle, the gas-driven urea system is tested to obtain test results. The standard pressure information is used to indicate the degree of pressure fluctuation applied to the urea nozzle during the injection of urea when the gas-driven urea system is in normal working condition. In response to the detection result indicating that the gas-driven urea system is in a faulty operating state, the fault type is determined based on the conversion efficiency of the catalytic reduction system, wherein the catalytic reduction system is used to convert a first substance in the gas into a second substance using urea, and the degree of pollution of the gas by the first substance is greater than the degree of pollution of the gas by the second substance.

2. The method according to claim 1, characterized in that, The method further includes: In response to the gas-driven urea system being in a second operating state, the standard pressure information is acquired, wherein the second operating state is used to indicate the state of the urea in the urea tank flowing to the plurality of urea nozzles; In response to acquiring the standard pressure information, the state of the gas-driven urea system is switched from the second operating state to the first operating state.

3. The method according to claim 2, characterized in that, The standard pressure information includes first standard pressure information, which indicates the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea by the multiple urea nozzles when the gas-driven urea system is in the normal state. Acquiring the standard pressure information in response to the gas-driven urea system being in the second operating state includes: In response to the air-driven urea system being in a second operating state and the absence of the first standard pressure information in the vehicle's electronic control unit, the system controls multiple urea nozzles to synchronously inject urea at a preset duty cycle. During the urea injection process, the system acquires first pressure change information, a first minimum pressure value, and a first maximum pressure value of the urea nozzles within a preset number of injection cycles. The first pressure change information is used to indicate the degree of pressure change of the urea nozzles during the synchronous urea injection process. Determine the first pressure difference between the first maximum pressure value and the first minimum pressure value within the same injection cycle; Based on the preset number of the first pressure difference values, the first standard pressure change information of the gas-driven urea system is determined; Based on the first labeled pressure change information and the remaining urea level, the first standard pressure information is determined; In response to the presence of the first standard pressure information in the electronic control unit, the first standard pressure information is obtained from the electronic control unit.

4. The method according to claim 2, characterized in that, The standard pressure information includes second standard pressure information, which indicates the degree of pressure fluctuation applied to the multiple urea nozzles during the alternating injection of urea by the multiple urea nozzles when the gas-driven urea system is in the normal state. Acquiring the standard pressure information in response to the gas-driven urea system being in the second operating state includes: In response to the air-driven urea system being in a second operating state and the absence of the second standard pressure information in the electronic control unit of the vehicle, the system controls multiple urea nozzles to alternately inject urea at a preset duty cycle. During the injection of urea, the system acquires the second pressure change information, the second minimum pressure value, and the second maximum pressure value of the urea nozzles within a preset number of injection cycles. The second pressure change information is used to represent the degree of change in the pressure of the urea nozzles during the alternating injection of urea. Determine the second pressure difference between the second maximum pressure value and the second minimum pressure value within the same injection cycle; Based on the preset number of second pressure difference values, the second standard pressure change information of the gas-driven urea system is determined; Based on the second labeled pressure change information and the remaining urea level, the second standard pressure information is determined; In response to the presence of the second standard pressure information in the electronic control unit, the second standard pressure information is obtained from the electronic control unit.

5. The method according to claim 1, characterized in that, In response to the gas-driven urea system being in a first operating state, the pressure information of the urea nozzle is acquired, including: In response to the air-driven urea system being in a first working state, the minimum and maximum third pressure values ​​of the urea nozzle are obtained within a preset number of injection cycles, and the duty cycle is obtained. In response to the duty cycle being within a preset duty cycle range, a third pressure difference is determined between the maximum value of the third pressure and the minimum value of the third pressure within the same injection cycle; The pressure information is determined based on the third pressure difference.

6. The method according to claim 5, characterized in that, The standard pressure information includes first standard pressure information, which indicates the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea by the multiple urea nozzles when the gas-driven urea system is in the normal state. Based on the pressure information, the standard pressure information of the gas-driven urea system, and the duty cycle of the urea nozzles, the gas-driven urea system is tested to obtain test results, including: If the difference between the pressure information and the first standard pressure information is less than a first threshold, the detection result is determined to be that the gas-driven urea system is in the fault state.

7. The method according to claim 6, characterized in that, The standard pressure information includes second standard pressure information, which indicates the degree of pressure fluctuation applied to the multiple urea nozzles during the alternating injection of urea by the multiple urea nozzles when the gas-driven urea system is in the normal state. In response to the detection result indicating that the gas-driven urea system is in a fault state, the fault type of the fault state is determined based on the conversion efficiency of the catalytic reduction system, including: In response to the detection result indicating that the gas-driven urea system is in a fault state, multiple urea nozzles are controlled to alternately spray urea at a preset duty cycle, and during the spraying of urea, the minimum and maximum fourth pressure values ​​of the urea nozzles are obtained within a preset number of spray cycles. Determine the fourth pressure difference between the maximum and minimum fourth pressure values ​​within the same injection cycle; Based on the fourth pressure difference value, pressure sub-information of the urea nozzle is determined, wherein the pressure sub-information is used to represent the degree of pressure fluctuation applied to multiple urea nozzles during the alternating injection of urea; In response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, a correction operation is performed on the gas-driven urea system and the catalytic reduction system. Obtain the conversion efficiency of the catalytic reduction system after performing the correction operation; Based on the conversion efficiency, the fault type is determined.

8. The method according to claim 7, characterized in that, The fault types include urea nozzle faults. Based on the conversion efficiency, the fault types are determined, including: In response to the conversion efficiency being less than the conversion efficiency threshold, the fault type is determined to be a urea nozzle fault.

9. The method according to claim 7, characterized in that, The gas-driven urea system includes a urea tank. In response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, a correction operation is performed on the gas-driven urea system, including: In response to the difference between the pressure sub-information and the second standard pressure information being less than a first threshold, the pressure in the urea tank is increased to a preset pressure. The difference between the pressure sub-information and the second standard pressure information is re-determined; In response to the difference between the re-determined pressure sub-information and the second standard pressure information being less than a second threshold, it is determined that the correction operation has been completed for the gas-driven urea system.

10. The method according to claim 7, characterized in that, Performing the correction operation on the catalytic reduction system includes: During the correction operation performed on the catalytic reduction system, the target ratio in the catalytic reduction system is adjusted to obtain the adjusted target ratio, wherein the target ratio is used to represent the proportion by which the catalytic reduction system reduces the first substance.

11. A fault type determination device for a gas-driven urea system in a vehicle, characterized in that, The gas-driven urea system includes multiple urea nozzles and a catalytic reduction system; the device includes: The acquisition unit is configured to acquire pressure information of multiple urea nozzles in response to the gas-driven urea system being in a first working state, wherein the first working state is an injection state in which urea is injected into the gas discharged by the vehicle synchronously using multiple urea nozzles, and the pressure information is used to indicate the degree of pressure fluctuation applied to the multiple urea nozzles during the synchronous injection of urea. The detection unit is used to detect the gas-driven urea system based on the pressure information, the standard pressure information of the urea nozzle, and the duty cycle of the urea nozzle, and obtain the detection result. The standard pressure information is used to indicate the degree of pressure fluctuation applied to the urea nozzle during the injection of urea when the gas-driven urea system is in normal working condition. A determining unit is configured to, in response to the detection result indicating that the gas-driven urea system is in a faulty operating state, determine the fault type of the fault state based on the conversion efficiency of the catalytic reduction system, wherein the catalytic reduction system is used to convert a first substance in the gas into a second substance using urea, and the degree of pollution of the gas by the first substance is greater than the degree of pollution of the gas by the second substance.

12. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 10.

13. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 10.

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