A method and system for detecting a fault of a urea pump

Abstract

This application provides a fault detection method and fault monitoring system for a urea pump. The method includes: acquiring abnormal pump pressure data based on monitored pump pressure; determining whether the urea pump has experienced an abnormal pump pressure based on the abnormal pump pressure data; recording one instance of abnormal pump pressure based on the recorded abnormal pump pressure data; and reporting a urea pump fault when N abnormal pump pressure data are recorded, where N≥4. As can be seen from the above, this method can determine whether the urea pump has experienced an abnormal pump pressure based on the pump pressure data, and further determine whether the urea pump has malfunctioned based on the number of abnormal pump pressure data. Therefore, this fault detection method can determine urea pump faults based on abnormal pump pressure, thus enabling early identification of urea pump faults before the urea pump fails to build pressure due to serious malfunctions. This allows for remedial measures such as repair to the urea pump, preventing serious malfunctions such as pump damage, saving users the cost of replacing the urea pump, and improving user satisfaction.

Description

Technical Field

[0001] This application relates to the field of exhaust gas treatment technology, and in particular to a method for detecting faults in a urea pump and a urea pump fault detection system. Background Technology

[0002] Currently, selective catalytic reduction (SCR) aftertreatment technology has been widely applied to China V and China VI vehicles. Systems using SCR aftertreatment technology typically require a urea solution storage device, i.e., a urea tank.

[0003] During the use of urea pumps, abnormal urea pump pressure may occur due to reasons such as leakage in the urea pump pressure pipe, affecting the NO concentration in the exhaust gas. x The effectiveness of treatment can thus affect emission consistency.

[0004] However, although the aforementioned urea pump pressure leakage will affect exhaust gas treatment, it may not have caused a serious failure of the urea pump to build up pressure, so it cannot trigger fault identification and report a fault. Summary of the Invention

[0005] In view of this, this application provides a method for fault detection of a urea pump, the scheme of which is as follows:

[0006] A method for detecting faults in an engine urea pump, comprising:

[0007] Monitor the pump pressure of the urea pump, and obtain abnormal pump pressure data based on the pump pressure of the urea pump. The abnormal pump pressure data is the pump pressure data of the urea pump within a first preset range within a certain period of time, where the pump pressure within the first preset range is less than the threshold pump pressure of the urea pump.

[0008] Based on the abnormal pump pressure data, determine whether the urea pump has experienced an abnormal pump pressure.

[0009] If the pump pressure of the urea pump is found to be abnormal, record one instance of abnormal pump pressure.

[0010] When N abnormal pump pressures are recorded, a urea pump malfunction is reported, where N ≥ 4.

[0011] Optionally, determining whether the urea pump has an abnormal pump pressure based on the abnormal pump pressure data includes:

[0012] Obtain the lowest pump pressure time from the pump pressure anomaly data, where the lowest pump pressure time is the time corresponding to the lowest pump pressure in the pump pressure anomaly data.

[0013] Obtain the urea pump pressure at the first moment before the lowest pump pressure moment, and determine whether the urea pump pressure at the first moment is within the range of the urea pump threshold pressure.

[0014] If the urea pump pressure at the first moment is within the range of the urea pump threshold pressure, it is determined that the urea pump pressure is abnormal, and an abnormal pump pressure is recorded.

[0015] Optionally, determining whether the urea pump pressure is abnormal based on the abnormal pump pressure data also includes:

[0016] If the urea pump pressure at the first moment is less than the urea pump threshold pressure, obtain the urea pump pressure at the second moment after the lowest pump pressure moment, and determine whether the urea pump pressure at the second moment is within the range of the urea pump threshold pressure.

[0017] If the urea pump pressure at the second moment is lower than the threshold pump pressure of the urea pump, it is determined that the urea pump pressure is abnormal, and a pump pressure abnormality is recorded.

[0018] If the urea pump pressure at the second moment is within the range of the urea pump threshold pressure, then it is determined that the urea pump pressure is normal.

[0019] Optionally, the value range of the first moment is from 300s to 500s before the moment of the lowest pump pressure, including the endpoint value; the value range of the second moment is from 50s to 80s after the moment of the lowest pump pressure, including the endpoint value; the value range of the pump pressure within the first preset range is 0 to 7.5 bar; and the value range of the urea pump threshold pump pressure is 8.5 bar to 9.5 bar, including the endpoint value.

[0020] Optionally, when N instances of abnormal pump pressure are recorded, the urea pump malfunction report includes:

[0021] When N pump pressure abnormalities are recorded, the time of the N pump pressure abnormalities is obtained. The time of the N pump pressure abnormalities is the time elapsed from the start time of the first pump pressure abnormality to the end time of the Nth pump pressure abnormality.

[0022] Based on the time interval of the N pump pressure abnormalities, it is determined whether the urea pump has experienced a pump pressure abnormality.

[0023] If the time of the N pump pressure abnormalities is not greater than the preset time, a urea pump malfunction is reported.

[0024] If the time of the N pump pressure abnormalities exceeds the preset time, no fault is reported.

[0025] Optionally, the preset time is no greater than 4 hours.

[0026] Optionally, the fault detection method further includes:

[0027] When the pump pressure of the urea pump is detected to be less than or equal to the preset pump pressure, fault detection is initiated. The preset pump pressure is the pump pressure at which fault detection is initiated.

[0028] Next, determine whether the engine is started;

[0029] If it is determined that the engine has started, monitor the pump pressure of the urea pump and obtain abnormal pump pressure data based on the pump pressure of the urea pump.

[0030] If the engine is determined not to be running, a urea pump malfunction is reported based on the urea quality of the urea pump.

[0031] Optionally, if it is determined that the engine has not started, a urea pump fault report based on the urea quality of the urea pump includes:

[0032] If it is determined that the engine is not started, the urea quality of the urea pump is obtained, and it is determined whether the urea quality of the urea pump is within a second preset range.

[0033] If the urea quality of the urea pump is within the second preset range, a urea pump malfunction is reported.

[0034] The second preset range is 20% to 31%, including endpoint values.

[0035] A urea pump fault detection system for detecting faults in an engine urea pump, comprising:

[0036] A pump pressure monitoring module is used to monitor the pump pressure of the urea pump and obtain abnormal pump pressure data based on the pump pressure of the urea pump. The abnormal pump pressure data is the pump pressure data of the urea pump within a first preset range within a certain period of time, where the pump pressure within the first preset range is less than the threshold pump pressure of the urea pump.

[0037] The judgment module uses the abnormal pump pressure data to determine whether the pressure of the urea pump is abnormal.

[0038] If the information processing module determines that the pump pressure is abnormal, the information processing module records one pump pressure abnormality, and when N pump pressure abnormalities are recorded, it reports a urea pump malfunction, where N≥4.

[0039] Optionally, the fault monitoring system also includes a urea quality sensor, which is used to obtain the urea quality of the urea pump.

[0040] The judgment module is also used to determine whether the urea quality of the urea pump is within a second preset range;

[0041] If the urea quality of the urea pump is within the second preset range, the information processing module is also used to report a urea pump malfunction.

[0042] The second preset range is 20% to 31%, including endpoint values.

[0043] Compared with the prior art, the beneficial effects of the technical solution of this application are as follows:

[0044] The fault detection method provided in this application includes: monitoring the urea pump pressure; acquiring abnormal pump pressure data based on the monitored urea pump pressure; determining whether the urea pump has experienced an abnormal pump pressure based on the abnormal pump pressure data; recording one instance of abnormal pump pressure when an abnormal pump pressure is detected; and reporting a urea pump fault when N instances of abnormal pump pressure are recorded, where N≥4. As can be seen from the above, this fault detection method can determine whether the urea pump has experienced an abnormal pump pressure based on the pump pressure data, and further determine whether the urea pump has malfunctioned based on the number of abnormal pump pressure records. Therefore, this fault detection method can determine urea pump faults based on abnormal pump pressure, thus enabling early identification of urea pump faults before they cause a serious malfunction leading to a failure to build pressure. In other words, it allows for early identification of urea pump faults in the early stages of serious malfunctions, enabling remedial measures such as repair to be taken to avoid serious damage to the urea pump, saving users the cost of replacing the urea pump and improving user satisfaction. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0046] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0047] Figure 1 A flowchart of a urea pump fault detection method provided in this application;

[0048] Figure 2 The urea quality curve and pump pressure curve of the urea pump;

[0049] Figure 3A flowchart of another urea pump fault detection method provided in this application. Detailed Implementation

[0050] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely one area of ​​this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0051] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] As described in the background section, urea pump pressure leakage can cause abnormal pump pressure, specifically resulting in the urea pump pressure dropping intermittently to around 7500 mbar to 0, and then gradually rising back to around 9 bar, affecting emission consistency. However, while urea pump pressure leakage does affect exhaust gas treatment, it may not be severe enough to cause the urea pump to fail to build up pressure. Therefore, existing fault detection programs cannot trigger fault identification and report the fault, making early identification of urea pump faults difficult and hindering early prevention.

[0053] In addition to the aforementioned impact of urea pump pressure leakage on exhaust gas treatment, dust contamination in the urea pump can also lead to abnormal urea pump pressure. However, since this is not severe enough to cause the urea pump to fail to build pressure, it cannot trigger fault identification and report a fault.

[0054] Based on this, this application provides a method for testing a urea pump, used for fault detection of the engine urea pump, such as... Figure 1 As shown, Figure 1 A flowchart of a fault detection method for a urea pump provided in this application is included, the fault detection method comprising:

[0055] S1: Monitor the pump pressure of the urea pump, and obtain abnormal pump pressure data based on the pump pressure. The abnormal pump pressure data is the pump pressure data of the urea pump within a first preset range over a period of time, where the pump pressure within the first preset range is less than the threshold pump pressure of the urea pump. It should be noted that step S1 specifically involves monitoring the pump pressure of the urea pump in real time during engine operation and obtaining abnormal pump pressure data based on the monitored pump pressure. It should also be noted that, as... Figure 2 As shown, the threshold pump pressure of the urea pump is the pump pressure that maintains the normal operation of the urea pump after it has built up pressure, and the pump pressure needs to be maintained at the threshold pump pressure after the urea pump has built up pressure.

[0056] S2: Determine whether the urea pump has an abnormal pump pressure based on the abnormal pump pressure data.

[0057] S3: If it is determined that the pump pressure of the urea pump is abnormal, record one pump pressure abnormality.

[0058] S4: When N instances of abnormal pump pressure are recorded, report the urea pump malfunction, where N ≥ 4. It should be noted that if only one instance of abnormal pump pressure is recorded, meaning the urea pump only experiences an abnormal pressure once, it indicates that the abnormal pressure is intermittent and not caused by a urea pump malfunction. Therefore, the fault monitoring method includes reporting the urea pump malfunction when N instances of abnormal pump pressure are recorded, where N ≥ 4, to avoid misdiagnosing such intermittent situations as urea pump malfunctions.

[0059] Specifically, as described above, the urea pump fault detection method provided in this application includes real-time monitoring of the urea pump's pump pressure data, acquiring abnormal pump pressure data based on the monitored data, and then determining whether the urea pump has experienced an abnormal pump pressure based on this data. Each instance of an abnormal pump pressure is recorded. When N instances of abnormal pump pressure are recorded, the urea pump is deemed to have experienced an abnormal pump pressure, indicating a urea pump malfunction, and a urea pump fault is reported. Therefore, the fault detection method provided in this application can determine whether the urea pump has experienced an abnormal pump pressure based on its pump pressure data, and further determine whether the urea pump has malfunctioned based on the number of abnormal pump pressure occurrences. This allows the method to identify urea pump faults before they cause a serious malfunction that prevents pressure build-up, enabling early identification of urea pump faults. This allows for remedial measures such as repair to prevent serious damage, saving users the cost of replacing the urea pump and improving user satisfaction.

[0060] For step S2, determining whether the urea pump pressure is abnormal based on the pump pressure anomaly data includes:

[0061] The lowest pump pressure time in the urea pump anomaly data is obtained, where the lowest pump pressure time is the time corresponding to the lowest pump pressure in the pump pressure data. It should be noted that the pump pressure data monitored in step S1 includes both the pump pressure and the time corresponding to each pump pressure. Therefore, step S2 can obtain the lowest pump pressure time in the pump pressure anomaly data based on the pump pressure anomaly data, i.e., the time corresponding to the lowest pump pressure in the pump pressure anomaly data.

[0062] After obtaining the minimum pump pressure time, based on the minimum pump pressure time, the urea pump pressure at the first moment before the minimum pump pressure time is obtained, and it is determined whether the urea pump pressure at the first moment is within the range of the urea pump threshold pump pressure.

[0063] If the urea pump pressure at the first moment is within the range of the urea pump threshold pressure, it is determined that the urea pump pressure is abnormal, and an abnormal pump pressure is recorded.

[0064] Specifically, in this embodiment, the lowest pump pressure time in the pump pressure anomaly data is obtained, and the urea pump pressure at the first moment before the lowest pump pressure time is obtained based on the lowest pump pressure time. If the urea pump pressure at the first moment is within the range of the urea pump threshold pump pressure, it indicates that the urea pump pressure has decreased between the first moment and the lowest pump pressure time and has not been maintained at the threshold pump pressure, thus it can be determined that the urea pump has experienced a pump pressure anomaly. Therefore, when the urea pump pressure at the first moment is within the range of the urea pump threshold pump pressure, this fault monitoring method determines that the urea pump pressure is abnormal and records a pump pressure anomaly. This allows the fault detection method to determine urea pump faults based on pump pressure anomalies, enabling early identification of urea pump faults, avoiding serious faults such as urea pump damage, saving users the cost of replacing urea pumps, and improving user satisfaction.

[0065] It should be noted that the above embodiments have discussed determining that the urea pump pressure is abnormal when the urea pump pressure at the first moment is within the range of the urea pump threshold pressure. However, if the urea pump pressure at the first moment is not within the range of the urea pump threshold pressure, that is, if the urea pump pressure at the first moment is less than the urea pump threshold pressure, it does not necessarily mean that the urea pump has not experienced a pressure abnormality. Therefore, based on the above embodiments, in one embodiment of this application, determining whether the urea pump pressure is abnormal based on the pump pressure abnormality data further includes:

[0066] If the urea pump pressure at the first moment is less than the urea pump threshold pressure, obtain the urea pump pressure at the second moment after the lowest pump pressure moment, and determine whether the urea pump pressure at the second moment is within the range of the urea pump threshold pressure.

[0067] If the urea pump pressure at the second moment is lower than the threshold pump pressure of the urea pump, it is determined that the urea pump pressure is abnormal, and an abnormal pump pressure is recorded.

[0068] If the urea pump pressure at the second moment is within the range of the urea pump threshold pressure, then it is determined that the urea pump pressure is normal.

[0069] Specifically, in this embodiment of the application, in order to determine whether the urea pump pressure is abnormal when the urea pump pressure at the first moment is less than the urea pump threshold pressure, if the urea pump pressure at the first moment is less than the urea pump threshold pressure, the urea pump pressure at the second moment after the lowest pump pressure moment is obtained. If the urea pump pressure at the second moment is lower than the urea pump threshold pressure, it means that the urea pump pressure from the first moment to the lowest pump pressure moment, and from the lowest moment to the second moment, is lower than the urea pump threshold pressure. This indicates that after the urea pump pressure drops at the first moment, it does not rise back to the threshold pump pressure at the second moment, indicating that the urea pump has a pump pressure abnormality. At this time, a pump pressure abnormality is recorded, and the cause of the pump pressure abnormality may be the abnormal pressure build-up of the urea pump due to pipeline leakage.

[0070] Additionally, if the urea pump pressure at the first moment is less than the urea pump threshold pressure, the urea pump pressure at the second moment after obtaining the lowest pump pressure is determined. If the urea pump pressure at the second moment is within the range of the urea pump threshold pressure, it indicates that the urea pump pressure has risen to the threshold pressure from the first moment to the second moment. This means that the urea pump is in the pressure-building process from the first moment to the second moment. At this time, there is no pump pressure abnormality and the urea pump is not faulty. The lowest pump pressure that occurs during this process is a pump pressure fluctuation during the pressure-building process and does not belong to a pump pressure abnormality.

[0071] It should be noted that the aforementioned lowest pump pressure time refers to the time corresponding to the minimum pump pressure during the period when the urea pump pressure drops. One lowest pump pressure time corresponds to one first time and one second time. When there are multiple lowest pump pressure times in the abnormal pump pressure data, there are also multiple corresponding first and second times. Each time a lowest pump pressure occurs, steps S2 and S3 above are repeated.

[0072] It should also be noted that if the urea pump pressure at the first moment is within the urea pump's threshold pressure range, it indicates that the urea pump pressure is abnormal. In subsequent steps, the pump pressure at the second moment can be obtained, or it can be omitted. Specifically, when obtaining the pump pressure at the second moment, if the pump pressure at the second moment is less than the urea pump's threshold pressure, it indicates that the pump pressure has decreased and has not risen back to the threshold pressure within a certain period of time, indicating that the urea pump has a pressure abnormality. This should be combined with the case where the urea pump pressure at the first moment is within the urea pump's threshold pressure range and recorded as one pump pressure abnormality. If the pump pressure at the second moment is within the urea pump's threshold pressure range, it indicates that the urea pump pressure has decreased and then risen back to the threshold pressure between the first and second moments, indicating that the urea pump has a pressure abnormality. This should also be combined with the case where the urea pump pressure at the first moment is within the urea pump's threshold pressure range and recorded as one pump pressure abnormality. Therefore, when the urea pump pressure at the first moment is within the range of the urea pump threshold pressure, the record of the pump pressure anomaly will be the same regardless of whether the pump pressure at the second moment is obtained or not. Thus, when the urea pump pressure at the first moment is within the range of the urea pump threshold pressure, the pump pressure at the second moment can be obtained or not, depending on the specific situation.

[0073] Optionally, in one embodiment of this application, the first time point is taken as 300s to 500s before the lowest pump pressure time point, including the endpoint value; the second time point is taken as 50s to 80s after the lowest pump pressure time point, including the endpoint value; the pump pressure within the first preset range is 0 to 7.5 bar; and the urea pump threshold pump pressure is taken as 8.5 bar to 9.5 bar, including the endpoint value. However, this application does not limit this, and in other embodiments of this application, the above-mentioned value ranges may also be other value ranges, depending on the specific circumstances.

[0074] Based on the above embodiments, in a preferred embodiment of this application, the first time is taken as the 400th second before the time of the lowest pump pressure, and the second time is taken as the 60th second after the time of the lowest pump pressure.

[0075] It should be noted that the time elapsed between N instances of abnormal urea pump pressure is also a crucial factor in determining urea pump malfunction. If N instances of abnormal pump pressure occur within a short period, it indicates a malfunction in the urea pump. Conversely, if N instances of abnormal pump pressure occur over a long period without significantly impacting the pump's operation, it suggests that the pump is not malfunctioning and the abnormal pressure is merely an occasional event. Therefore, in one embodiment of this application, for step S4, reporting a urea pump malfunction upon recording N instances of abnormal pump pressure includes:

[0076] When N pump pressure abnormalities are recorded, that is, when N pump pressure abnormalities occur, the time of the N pump pressure abnormalities is obtained. The time of the N pump pressure abnormalities is the time elapsed from the start time of the first pump pressure abnormality to the end time of the Nth pump pressure abnormality.

[0077] The time of the N pump pressure abnormalities is compared with a preset duration, which is the abnormal time threshold of the N pump pressure abnormalities. This abnormal time threshold represents the maximum time limit during which the urea pump is not judged as having pump pressure abnormality when there are N pump pressure abnormalities.

[0078] If the time of the N pump pressure abnormalities is not greater than a preset time, that is, the time of the N pump pressure abnormalities is less than or equal to the abnormal time threshold of the N pump pressure abnormalities, a urea pump fault is reported.

[0079] If the time of the N pump pressure abnormalities is greater than the preset time, that is, if the time of the N pump pressure abnormalities is greater than the abnormal time threshold of the N pump pressure abnormalities, no fault is reported.

[0080] Specifically, in this embodiment, when N pump pressure abnormalities are recorded, the time elapsed for each of those N abnormalities is obtained. If the time elapsed for the N abnormalities is not greater than a preset time (i.e., the time elapsed for the N abnormalities is less than an abnormal time threshold), it indicates that the time elapsed for the N abnormalities is relatively short, meaning the urea pump experienced N abnormalities within a short period, thus indicating a urea pump malfunction and a urea pump malfunction report is issued. Conversely, if the time elapsed for the N abnormalities is greater than a preset time (i.e., the time elapsed for the N abnormalities is greater than a preset time), it indicates that the urea pump experienced N abnormalities over a longer period, thus indicating that the urea pump did not malfunction and no urea pump malfunction report is issued.

[0081] Optionally, in one embodiment of this application, the preset time is no greater than 4 hours, that is, the abnormal time threshold for N pump pressure abnormalities is less than or equal to 4 hours, preferably equal to 4 hours. However, this application does not impose a limitation, and the specific value depends on the circumstances.

[0082] Based on any of the above embodiments, in one embodiment of this application, the fault detection method further includes:

[0083] Fault detection begins when the pump pressure of the urea pump is detected to be less than or equal to a preset pump pressure, where the preset pump pressure is the pump pressure at which fault detection begins. Optionally, the preset pump pressure is 0.3 bar.

[0084] Next, it is determined whether the engine has started.

[0085] If it is determined that the engine has started, monitor the pump pressure of the urea pump and obtain abnormal pump pressure data based on the pump pressure of the urea pump.

[0086] If the engine is determined not to be running, a urea pump malfunction is reported based on the urea quality of the urea pump.

[0087] Specifically, when the urea pump pressure is detected to be less than or equal to 0.3 bar, the fault detection process begins. Then, it is determined whether the engine is running. If the engine speed n is greater than or equal to 600 rpm, it indicates the engine is running. The urea pump pressure is monitored, and abnormal pump pressure data is obtained based on this pressure for further fault detection. If the engine speed is less than 600 rpm, it indicates the engine is not running. In this case, a urea pump fault is reported based on the urea quality. Therefore, the fault detection method provided in this application can detect urea pump faults regardless of whether the engine is running or not, demonstrating strong practicality.

[0088] As previously known, besides the impact of urea pump pressure leakage on exhaust gas treatment, dust contamination in the urea pump can also lead to abnormal urea pump pressure. Therefore, in one embodiment of this application, the fault monitoring method further includes: if it is determined that the engine has not started, reporting a urea pump fault based on the urea quality of the urea pump. Specifically, reporting a urea pump fault based on the urea quality of the urea pump if it is determined that the engine has not started includes:

[0089] The quality of urea from the urea pump is obtained, and it is determined whether the quality of urea from the urea pump is within a second preset range.

[0090] If the urea quality of the urea pump is within the second preset range, a urea pump malfunction is reported.

[0091] The second preset range is 20% to 31%, including endpoint values. It should be noted that, for example... Figure 2 As shown, the urea quality value of a typical urea pump should be 32.5%, and should be maintained at this value with slight fluctuations.

[0092] Specifically, in this embodiment, the fault detection method further includes acquiring the urea quality of the urea pump, specifically acquiring the urea quality of the urea inside the urea pump. If the urea quality of the urea pump is within a second preset range, it indicates that the urea concentration inside the urea pump is lower than a predetermined value, thus indicating that the urea pump has experienced urea dust contamination. Furthermore, when the urea quality of the urea pump is within the second preset range, a urea pump fault is reported. As can be seen from the above, the fault detection method also includes determining whether the urea pump has malfunctioned based on the urea quality of the urea pump. Therefore, this fault detection method can determine the urea pump fault in two ways, ensuring the accuracy and comprehensiveness of the fault detection method.

[0093] In addition, as described above, the fault detection method includes determining faults through pump pressure data and determining faults through urea quality, which helps to determine the root cause of urea pump faults and provides a basis for subsequent maintenance and repair.

[0094] Next, according to Figure 3 A urea pump fault detection method provided by the present application will be described in detail.

[0095] First, when it is recognized that the pump pressure p0 of the urea pump is less than or equal to 0.3 bar, the fault detection process starts. Then, it is determined whether the engine is started. If so, the pump pressure data is monitored, and pump pressure abnormal data is obtained based on the monitored pump pressure of the urea pump. Then, based on the pump pressure abnormal data, the pump pressure p1 of the urea pump 400 s before the lowest pump pressure moment is obtained, and it is judged whether p1 is within the threshold range of the threshold pump pressure. If so, a pump pressure abnormality is recorded once. If not, the pump pressure p2 of the urea pump 60 s after the lowest pump pressure moment is obtained, and it is judged whether p2 is within the threshold range of the threshold pump pressure. If not, a pump pressure abnormality is recorded once. The above steps are repeated until N pump pressure abnormalities are recorded, the urea pump fault is reported, and the fault detection process ends.

[0096] In addition, the detection process of the fault detection method further includes obtaining the urea quality Q of the urea pump. Specifically, if the engine is not started, the urea quality Q of the urea pump is obtained. If 20% < Q ≤ 31%, the urea pump fault is reported, and the fault detection process ends.

[0097] Correspondingly, the present application further provides a urea pump fault detection system for performing fault detection on an engine urea pump, and the fault detection method described in any of the above embodiments is applied to the fault detection system. The fault detection system includes:

[0098] A pump pressure monitoring module for monitoring the pump pressure of the urea pump and obtaining pump pressure abnormal data based on the pump pressure of the urea pump. The pump pressure abnormal data is pump pressure data within a first preset range of the pump pressure of the urea pump within a period of time, and the pump pressure within the first preset range is less than the threshold pump pressure of the urea pump.

[0099] A judgment module for judging whether the pressure of the urea pump is abnormal based on the pump pressure abnormal data.

[0100] An information processing module. If it is judged that the pump pressure is abnormal, the information processing module is used to record a pump pressure abnormality once, and when N pump pressure abnormalities are recorded, the urea pump fault is reported, where N ≥ 4.

[0101] Specifically, as described above, the pump pressure monitoring module in this fault monitoring system monitors the pump pressure data of the urea pump in real time and obtains abnormal pump pressure data based on the monitored data. Then, the judgment module determines whether the urea pump has experienced an abnormal pump pressure based on this abnormal data. The information processing module records the abnormal pump pressure data, recording each occurrence. When N abnormal pump pressure data are recorded, the system determines that the urea pump has an abnormal pump pressure and reports a urea pump fault. Therefore, this fault detection system can determine whether the urea pump has experienced an abnormal pump pressure based on its pump pressure data, and further determine whether the urea pump has malfunctioned based on the number of abnormal pump pressure data. This allows the system to identify urea pump faults before they occur due to serious malfunctions and prevent pressure build-up. In other words, it allows for early identification of urea pump faults in the early stages of serious malfunctions, enabling repair and remedial measures to be taken to prevent further damage and other serious failures. This saves users the cost of replacing the urea pump and improves user satisfaction.

[0102] Based on the above embodiments, in one embodiment of this application, the fault monitoring system further includes a urea quality sensor. The urea quality sensor is used to acquire the urea quality of the urea pump. The judgment module is further used to determine whether the urea quality of the urea pump is within a second preset range. If the urea quality of the urea pump is within the second preset range, the information processing module is further used to report a urea pump fault. The second preset range is 20% to 31%, including endpoint values.

[0103] Specifically, in this embodiment, the fault detection system can obtain the urea quality of the urea pump and report a urea pump fault when the urea quality of the urea pump is within a second preset range. As can be seen from the above, the fault detection method also includes determining whether the urea pump has malfunctioned based on the urea quality of the urea pump. Therefore, the fault detection method can determine the urea pump fault in two ways, ensuring the accuracy and comprehensiveness of the fault detection method.

[0104] In summary, this application provides a method and system for detecting urea pump faults. The fault detection method includes: acquiring abnormal pump pressure data based on monitored pump pressure; determining whether the urea pump has experienced an abnormal pump pressure based on the abnormal pump pressure data; recording one instance of abnormal pump pressure based on the recorded abnormal pump pressure data; and reporting a urea pump fault when N instances of abnormal pump pressure data are recorded, where N≥4. As can be seen from the above, this fault detection method can determine whether the urea pump has experienced an abnormal pump pressure based on the pump pressure data, and further determine whether the urea pump has malfunctioned based on the number of abnormal pump pressure data. Therefore, this fault detection method can determine urea pump faults based on abnormal pump pressure data, thereby enabling early identification of urea pump faults before the pump fails to build pressure due to a serious malfunction. In other words, it allows for early identification of urea pump faults in the early stages of serious malfunctions, enabling remedial measures such as repair to be taken, avoiding serious malfunctions such as pump damage, saving users the cost of replacing the urea pump, and improving user satisfaction.

[0105] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical areas between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant details can be found in the description of the method area.

[0106] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0107] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0108] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting faults in a urea pump, characterized in that, Used for fault detection of engine urea pump, including: Monitor the pump pressure of the urea pump, and obtain abnormal pump pressure data based on the pump pressure of the urea pump. The abnormal pump pressure data is the pump pressure data of the urea pump within a first preset range within a certain period of time. The pump pressure within the first preset range is less than the threshold pump pressure of the urea pump. The threshold pump pressure is the pump pressure that maintains the normal operation of the urea pump after it builds up pressure. Based on the abnormal pump pressure data, determine whether the urea pump has experienced an abnormal pump pressure. If the pump pressure of the urea pump is found to be abnormal, record one instance of abnormal pump pressure. When N abnormal pump pressures are recorded, the urea pump malfunction is reported, where N ≥ 4; The step of determining whether the urea pump has an abnormal pump pressure based on the abnormal pump pressure data includes: Obtain the lowest pump pressure time from the pump pressure anomaly data, where the lowest pump pressure time is the time corresponding to the lowest pump pressure during the time period when the pump pressure drops in the pump pressure anomaly data; Obtain the urea pump pressure at the first moment before the lowest pump pressure moment, and determine whether the urea pump pressure at the first moment is within the range of the urea pump threshold pressure. If the urea pump pressure at the first moment is within the range of the urea pump threshold pressure, it is determined that the urea pump pressure is abnormal, and an abnormal pump pressure is recorded. If the urea pump pressure at the first moment is less than the threshold pump pressure of the urea pump, obtain the urea pump pressure at the second moment after the moment of the lowest pump pressure, and determine whether the urea pump pressure at the second moment is within the range of the threshold pump pressure of the urea pump. If the urea pump pressure at the second moment is lower than the threshold pump pressure of the urea pump, it is determined that the urea pump pressure is abnormal, and a pump pressure abnormality is recorded. If the urea pump pressure at the second moment is within the range of the urea pump threshold pressure, then it is determined that the urea pump pressure is normal. The method of reporting a urea pump malfunction when N abnormal pump pressure readings are recorded includes: When N pump pressure abnormalities are recorded, the time of the N pump pressure abnormalities is obtained. The time of the N pump pressure abnormalities is the time elapsed from the start time of the first pump pressure abnormality to the end time of the Nth pump pressure abnormality. Determine whether the urea pump has experienced a pump pressure abnormality based on the time of the N pump pressure abnormalities. If the time of the N pump pressure abnormalities is not greater than the preset time, a urea pump malfunction is reported. If the time of the N pump pressure abnormalities exceeds the preset time, no fault is reported.

2. The urea pump fault detection method according to claim 1, characterized in that, The value range of the first moment is from 300s to 500s before the lowest pump pressure moment, including the endpoint value; the value range of the second moment is from 50s to 80s after the lowest pump pressure moment, including the endpoint value; the value range of the pump pressure within the first preset range is 0~7.5bar; the value range of the urea pump threshold pump pressure is 8.5bar~9.5bar, including the endpoint value.

3. The urea pump fault detection method according to claim 1, characterized in that, The preset time value is no greater than 4 hours.

4. The urea pump fault detection method according to claim 1, characterized in that, The fault detection method also includes: When the pump pressure of the urea pump is detected to be less than or equal to the preset pump pressure, fault detection is initiated. The preset pump pressure is the pump pressure at which fault detection is initiated. Next, determine whether the engine is started; If it is determined that the engine has started, monitor the pump pressure of the urea pump and obtain abnormal pump pressure data based on the pump pressure of the urea pump. If the engine is determined not to be running, a urea pump malfunction is reported based on the urea quality of the urea pump.

5. The urea pump fault detection method according to claim 4, characterized in that, If the engine is determined not to be started, a urea pump fault report based on the urea quality of the urea pump includes: If it is determined that the engine is not started, the urea quality of the urea pump is obtained, and it is determined whether the urea quality of the urea pump is within a second preset range. If the urea quality of the urea pump is within the second preset range, a urea pump malfunction is reported. The second preset range is 20% to 31%, including endpoint values.

6. A fault detection system for a urea pump, characterized in that, The method for detecting a urea pump according to any one of claims 1-5, used for detecting a fault in an engine urea pump, includes: A pump pressure monitoring module is used to monitor the pump pressure of the urea pump and obtain abnormal pump pressure data based on the pump pressure of the urea pump. The abnormal pump pressure data is the pump pressure data of the urea pump within a first preset range within a certain period of time, where the pump pressure within the first preset range is less than the threshold pump pressure of the urea pump. The judgment module determines whether the pressure of the urea pump is abnormal based on the pump pressure abnormality data; If the information processing module determines that the pump pressure is abnormal, the information processing module records one pump pressure abnormality, and when N pump pressure abnormalities are recorded, it reports a urea pump malfunction, where N≥4.

7. The urea pump fault detection system according to claim 6, characterized in that, The fault monitoring system also includes a urea quality sensor, which is used to obtain the urea quality of the urea pump. The judgment module is also used to determine whether the urea quality of the urea pump is within a second preset range; If the urea quality of the urea pump is within the second preset range, the information processing module is also used to report a urea pump malfunction. The second preset range is 20% to 31%, including endpoint values.

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