A method and device for preventing false diagnosis of urea concentration, electronic equipment and medium

Abstract

This invention relates to the field of diesel engine testing and provides a method, device, electronic device, and medium for preventing false alarms in urea concentration. The method is as follows: the engine is started; the current urea concentration value is read in real time, and a diagnostic window timer starts timing simultaneously; the current urea concentration value is compared with the urea concentration calibration value in real time; if the current urea concentration value is lower than the urea concentration calibration value, the low urea concentration timer starts timing; otherwise, timing stops; when the diagnostic window timer reaches the time calibration value, the low urea concentration time percentage is calculated, where the low urea concentration time percentage is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value; if the low urea concentration time percentage is greater than or equal to the low urea concentration time percentage calibration value, a low urea concentration fault is reported; if the low urea concentration time percentage is less than the low urea concentration time percentage calibration value, the urea concentration is normal, and the diagnosis ends.

Description

Technical Field

[0001] This invention relates to the field of diesel engine testing, and in particular to a method, device, electronic equipment, and medium for preventing false alarms about urea concentration. Background Technology

[0002] Urea concentration typically refers to the concentration of the urea solution in a diesel engine exhaust aftertreatment system, also known as AdBlue or DEF (diesel exhaust fluid), used to reduce nitrogen oxide emissions. SCR (Selective Catalytic Reduction) systems require precise urea injection; incorrect urea concentration can lead to excessive emissions or system malfunctions. Currently, urea concentration is primarily detected by urea concentration sensors. After detecting the urea concentration signal, the sensor sends it to the ECU control unit. The ECU processes the signal to determine if the urea solution in the diesel engine's urea tank is below the calibrated limit. If it is, the engine reports a low urea concentration fault. Most urea concentration sensors on the market are based on ultrasonic principles, relying on the different transmission speeds of ultrasound in liquids of varying concentrations to measure the concentration. Adding urea and vehicle vibrations can generate bubbles in the urea. If these bubbles enter the ultrasonic detection area, it can cause abnormal urea concentration measurements, resulting in false alarms.

[0003] Currently, in order to solve the problem of false alarms in urea concentration, some technical methods have been disclosed, as follows:

[0004] Patent CN113217159B discloses a method and apparatus for preventing false alarms related to urea quality faults. This method adds a urea quality replacement timer for urea filling timing, determining the start time of the timer based on the urea filling status before ECU power-on. If urea filling is detected after ECU power-on, the timer restarts from 0. When the value of the timer is less than a predetermined time, a standard urea solution mass is used for fault diagnosis. When the value is greater than or equal to the predetermined time, the timer is reset to 0, and the measurement value from the urea quality sensor is used for fault diagnosis. However, this method only uses the measurement value from the urea quality sensor for fault diagnosis and cannot effectively address the risk of false readings from the urea quality sensor when air bubbles appear in the urea tank during bumpy driving conditions.

[0005] Patent CN202310622315.9 discloses a method, apparatus, device, and storage medium to avoid false alarms due to abnormal urea concentration. After the controller is powered on or urea is added during power-on, the urea concentration is pre-detected for a period of time. If it is within acceptable limits, the acceptable urea concentration is locked for fault diagnosis. If it is not within acceptable limits, the operating mileage is accumulated, and then another pre-detection is performed to determine whether it is within acceptable limits. It can be understood that through two detections, the urea concentration can be accurately detected, effectively avoiding the problem of false alarms. However, this strategy of using accumulated operating mileage to determine urea concentration is too simplistic and unreasonable, with the following problems: 1. If the accumulated operating mileage... 1. The time frame is too long. For example, if the mileage setting is 100km as mentioned in the patent, and the vehicle speed is 80km / h, it would take more than an hour to conduct the second test. If the urea solution concentration is abnormal, it will not meet the requirements of reporting a fault in one WHTC cycle (transient test cycle for road engines, taking about 0.5h) or NRTC cycle (transient test cycle for non-road engines, taking about 0.35h); 2. If there are air bubbles in the urea tank during the second test, it is very likely that a low urea concentration fault will be reported due to the air bubbles, even though the urea concentration is actually normal. That is, this strategy cannot effectively avoid the influence of air bubbles on the diagnosis of urea quality. Summary of the Invention

[0006] The main purpose of this invention is to prevent the low concentration of urea solution in the aftertreatment of diesel engines (China VI or non-road stage IV) due to small bubbles from affecting the normal diagnosis of the ECU and causing false alarms. This invention discloses a method, device, electronic device and readable storage medium for preventing false alarms in urea concentration diagnosis.

[0007] The technical solution adopted in this invention is as follows:

[0008] In a first aspect, the present invention provides a method for preventing false alarms in urea concentration diagnosis; the method is as follows:

[0009] Engine start;

[0010] The current urea concentration value is read in real time, and the diagnostic window timer starts counting down.

[0011] The current urea concentration value is compared with the urea concentration calibration value in real time. If the current urea concentration value is lower than the urea concentration calibration value, the urea concentration low timer starts counting; otherwise, it stops counting.

[0012] When the diagnostic window timer reaches the time calibration value, the percentage of time with low urea concentration is calculated, where the percentage of time with low urea concentration is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value. If the percentage of time with low urea concentration is greater than or equal to the calibration value, a low urea concentration fault is reported. If the percentage of time with low urea concentration is less than the calibration value, the urea concentration is normal, and the diagnosis ends.

[0013] As a further technical solution, before starting the engine, the urea concentration of the previous driving cycle is retrieved and the current urea concentration is detected. If both concentrations are lower than the calibrated concentration, a fault of low urea solution concentration in the previous driving cycle is reported; otherwise, the fault of low urea solution concentration is cleared, and then the engine is started.

[0014] As a further technical solution, the aforementioned percentage calibration value is set to different values ​​according to the fault level.

[0015] As a further technical solution, the urea concentration low timer is an intermittent timer.

[0016] Secondly, the present invention also provides a diagnostic device for preventing false alarms about urea concentration, comprising:

[0017] Urea concentration acquisition module; used to read the current urea concentration value in real time;

[0018] Diagnostic window timer; used to time the detection process.

[0019] The comparison module is used to compare the current urea concentration value with the urea concentration calibration value in real time.

[0020] The urea concentration low timer is configured to start timing when the current urea concentration value is lower than the urea concentration calibration value; otherwise, it will not start timing.

[0021] The percentage calculation module is configured to calculate the percentage of time with low urea concentration when the diagnostic window timer reaches the time calibration value; the percentage of time with low urea concentration is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value.

[0022] The fault alarm module is configured to report a low urea concentration fault if the percentage of time with low urea concentration is greater than or equal to the calibrated value; if the percentage of time with low urea concentration is less than the calibrated value, the urea concentration is normal and no fault is reported.

[0023] As a further technical solution, the urea concentration low timer is an intermittent timer.

[0024] As a further technical solution, a fault pre-judgment module is also included, which is configured to call the urea concentration of the previous driving cycle and detect the current urea concentration before the engine starts. If both concentrations are less than the calibrated concentration, a fault of low urea solution concentration in the previous driving cycle is reported; otherwise, the fault of low urea solution concentration is cleared and the engine is started.

[0025] As a further technical solution, the aforementioned percentage calibration value is set to different values ​​according to the fault level.

[0026] Thirdly, the present invention also provides a urea concentration fault detection and control device, characterized in that it includes: at least one processor and a memory;

[0027] The memory stores computer-executed instructions;

[0028] The at least one processor executes computer execution instructions stored in the memory, causing the at least one processor to execute the urea concentration fault detection method.

[0029] Fourthly, the present invention also provides a readable storage medium, characterized in that the readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the urea concentration fault detection method.

[0030] Compared with the technical means of the prior art, the effective effects of the present invention are as follows:

[0031] This invention employs a large diagnostic window to calculate the percentage of time spent with low urea concentration, enabling the reporting of low urea concentration faults. This ingenious design effectively prevents false alarms, demonstrates strong adaptability, and addresses faults that are difficult to report but easy to resolve. Specifically, this invention accumulates and statistically analyzes the percentage of time spent with low concentration within a single diagnostic window (default 1200s, or 20 minutes), effectively avoiding false alarms about urea concentration. For example, if the low urea concentration percentage is set to 90%, it means that a fault would only be reported after 18 minutes of sustained low urea concentration. Generally, the impact of air bubbles on urea quality is transient and unlikely to last for more than 10 minutes unless the urea concentration is genuinely low. Therefore, this invention effectively avoids false alarms by accumulating and statistically analyzing the percentage of time spent with low concentration within a single diagnostic window. If the urea solution concentration is abnormal, it can promptly report a low urea concentration fault (CDmin) within one WHTC / NRTC. This effectively avoids the impact of air bubbles in the urea tank on the normal diagnosis of urea quality during normal vehicle operation (bumpy road conditions). The diagnostic strategy proposed in this application, though simple, is ingeniously conceived and highly practical. It ensures the normal reporting of real faults within a single WHTC / NRTC cycle while effectively avoiding false alarms caused by bubble effects. Moreover, the faults are difficult to report and easy to resolve, resulting in a good customer experience. Attached Figure Description

[0032] Figure 1 A schematic flowchart of the method for preventing false alarms of urea concentration proposed in this invention;

[0033] Figure 2 The diagnostic logic diagram for preventing false alarms of urea concentration proposed in the embodiments of the present invention;

[0034] Figure 3A schematic diagram of the device for preventing false alarms of urea concentration proposed in this invention;

[0035] Figure 4 A schematic diagram of a device for preventing false alarms of urea concentration in an embodiment of the present invention; Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] Glossary: ​​Cdmin fault in this embodiment: When the urea solution in the diesel engine urea tank is lower than the calibrated limit (e.g., 25.5%, different manufacturers define the limit differently), the engine reports a low urea solution concentration fault.

[0038] In existing technologies, bubbles in the urea tank are generally generated by vehicles on bumpy roads, especially in off-road vehicles such as loaders and excavators, where the working environment makes them more prone to this problem. Therefore, bubbles are often transient. From a diesel engine design perspective, it is undesirable for bubbles to have any impact on urea quality diagnosis under normal urea concentrations. Without a suitable fault diagnosis strategy, if bubbles appear in the urea solution, the urea quality sensor may measure an underestimation of the urea concentration. If the bubbles are very large, the urea quality sensor may exceed its range and lock in a false value. To solve this problem, this embodiment provides a method for preventing false urea concentration alarms, which can be applied to emission aftertreatment systems and can resolve the problem of false urea concentration alarms.

[0039] Specifically, this embodiment provides a diagnostic method for preventing false alarms in urea concentration; the method is as follows:

[0040] Engine start;

[0041] The current urea concentration value is read in real time, and the diagnostic window timer starts counting down.

[0042] The current urea concentration value is compared with the urea concentration calibration value in real time. If the current urea concentration value is lower than the urea concentration calibration value, the urea concentration low timer starts counting; otherwise, it stops counting.

[0043] When the diagnostic window timer reaches the time calibration value, the percentage of time with low urea concentration is calculated, where the percentage of time with low urea concentration is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value. If the percentage of time with low urea concentration is greater than or equal to the calibration value, a low urea concentration fault is reported. If the percentage of time with low urea concentration is less than the calibration value, the urea concentration is normal, and the diagnosis ends.

[0044] The diagnostic method for preventing false alarms regarding urea concentration proposed in this embodiment calculates the percentage of time spent with low urea concentration within a large diagnostic window, thereby enabling the reporting of low urea concentration faults. This ingenious design effectively prevents false alarms, demonstrates strong adaptability, and addresses faults that are difficult to report but easy to resolve. Specifically, this invention accumulates and statistically analyzes the percentage of time spent with low concentration within a single diagnostic window (default 1200s, or 20 minutes), effectively avoiding false alarms. For example, if the low urea concentration percentage is set to 90%, it means that a low urea concentration must persist for 18 minutes before a fault can be reported. Generally, the impact of bubbles on urea quality is transient and unlikely to last for more than 10 minutes unless the urea concentration is genuinely low, in which case a fault report is necessary. Therefore, this invention effectively avoids false alarms by setting a single diagnostic window and accumulating and statistically analyzing the percentage of time spent with low concentration. If the urea solution concentration is abnormal, it can promptly report the low urea concentration CDmin fault within 1 WHTC / NRTC; it can effectively avoid the influence of air bubbles in the urea tank on the normal diagnosis of urea quality during normal vehicle operation (bumpy road conditions).

[0045] The following detailed description, in conjunction with the accompanying drawings, illustrates the proposed method for preventing false alarms in urea concentration. Figure 1 , Figure 1 The diagram shown is a flowchart of a method for avoiding false alarms of abnormal urea concentration provided in this embodiment, including the following steps:

[0046] The power switch for the engine ECU unit is T15. When the switch is closed (the ECU receives 24V power), the ECU is in working condition. When the key switch T15 is turned off, the engine will shut off naturally.

[0047] When the engine's T15 is powered on, the ECU unit first retrieves the urea concentration C0 from the previous driving cycle and obtains the current urea concentration C1 detected by the urea quality sensor. If both the previous driving cycle urea concentration C0 and the current urea concentration C1 are less than the urea concentration calibration value C... 标定 If the fault persists, the driver will be prompted to disconnect T15 and replace the urea solution with a suitable one. Otherwise, the system will automatically perform one Cdmin fault clearing operation and then start the engine.

[0048] After the engine is started, the ECU unit detects and reads the urea concentration C1 in real time via the urea quality sensor (without filtering). At this time, the diagnostic window timer T0 in the ECU unit starts counting. When T0 reaches the time calibration value T... 标定 When the urea concentration is low, it is included in the calculation of the proportion of time with low urea concentration; otherwise, it is not calculated. It should be noted that the time calibration value T... 标定 It can be modified appropriately according to the actual situation. The default setting is 1200s, which ensures that a fault is reported within one transient emission cycle.

[0049] At the same time, the real-time urea concentration C1 and the urea concentration calibration value C 标定 If the initial urea concentration C1 is lower than the urea concentration calibration value C, then the comparison will be made. 标定 If the urea concentration in the ECU unit is low, the T1 timer starts counting; otherwise, it stops counting. It is important to emphasize that the T1 timer is an incrementing timer, an intermittent timer. 标定 The setting can be adjusted according to the actual use of the engine; the default setting is 25.5%.

[0050] When the diagnostic window timer T0 equals the time calibration value T 标定 At that time, the ECU begins calculating the percentage of time A with low urea concentration. 占 =T1 / T0, if the urea concentration is low, the percentage of time A is... 占 Greater than or equal to the calibration value A for the proportion of time with low urea concentration 标定 The system reports a low urea concentration fault; after reporting the fault, both T0 and T1 are cleared to 0, and then the process continues to the next diagnostic window. If the low urea concentration time accounts for A... 占 Less than the percentage calibration value A 标定 If the urea concentration is normal, the diagnosis is terminated and the urea will not be used for diagnosis again in this driving cycle.

[0051] It should be noted that the calibration value A represents the percentage of time with low urea concentration. 标定 It can be modified appropriately according to the engine; the default setting is 90%.

[0052] Can target A 占 The numerical values ​​are set to indicate different levels of fault severity, and then different levels of protective measures are taken according to the fault level to ensure the engine's safety and reliability.

[0053] Specifically, the aforementioned driving cycle refers to a complete process from power-on to power-off or from ignition to shutdown of the vehicle. Related technologies often perform multiple urea concentration checks periodically within a driving cycle. In this embodiment, "urea concentration C0 of the previous driving cycle" refers to the average urea concentration of the previous driving cycle.

[0054] The diagnostic strategy proposed in this embodiment, though simple, is ingeniously conceived and highly practical. It ensures the normal reporting of real faults within a single WHTC / NRTC cycle while effectively avoiding false alarms caused by bubble effects. Moreover, faults are difficult to report and easy to resolve, resulting in a good customer experience.

[0055] Reference Figure 2 This embodiment also provides a diagnostic system for preventing false alarms in urea concentration. The system mainly includes a urea concentration acquisition module 201, which is used to read the current urea concentration value in real time.

[0056] Diagnostic window timer 202; used to time the detection process.

[0057] Comparison module 203 is used to compare the current urea concentration value with the urea concentration calibration value in real time.

[0058] The urea concentration low timer 204 is configured to start timing when the current urea concentration value is lower than the urea concentration calibration value; otherwise, it will not start timing.

[0059] The percentage calculation module 205 is configured to calculate the percentage of time with low urea concentration when the diagnostic window timer reaches the time calibration value; the percentage of time with low urea concentration is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value.

[0060] The fault alarm module 206 is configured to report a low urea concentration fault if the proportion of time with low urea concentration is greater than or equal to the calibrated value of the proportion of time with low urea concentration; if the proportion of time with low urea concentration is less than the calibrated value of the proportion of time with low urea concentration, the urea concentration is normal and no fault is reported.

[0061] Specifically, the urea concentration acquisition module 201, diagnostic window timer 202, comparison module 203, low urea concentration timer, percentage calculation module, and fault alarm module are all integrated in the ECU control unit; among them, the urea concentration acquisition module is used to acquire the urea concentration value detected by the urea quality sensor.

[0062] As a further technical solution, the urea concentration false alarm diagnostic system also includes a fault pre-judgment module, which is configured to call the urea concentration of the previous driving cycle and detect the current urea concentration before the engine is started. If both concentrations are less than the calibrated concentration, a fault of low urea solution concentration in the previous driving cycle is reported; otherwise, the fault of low urea solution concentration is cleared and the engine is started.

[0063] Of course, the ECU control unit is also connected to a liquid level sensor and a temperature sensor; among them, the urea quality sensor, liquid level sensor, and temperature sensor are located in the urea tank. The engine is connected in sequence to the DOC (diesel oxidation catalyst), DPF (diesel particulate filter), and SER (selective catalytic reduction) system. The urea pump draws urea from the urea tank and sprays urea into the SER system through nozzles. The ECU controls the metering of urea spray through the urea pump.

[0064] The system includes: a urea level sensor to measure the urea level in the urea tank for identifying the urea filling status; a urea mass sensor to measure the current urea mass in the tank; and a urea temperature sensor.

[0065] Used to measure the temperature of urea inside the urea tank.

[0066] The ECU unit is the central processing unit for engine control in a vehicle, used for calculating and monitoring various engine data and actions. In this invention, it serves as the carrier for implementing the method. When the engine's T15 is powered on, the ECU unit's fault pre-judgment module first calls the urea concentration C0 from the previous driving cycle and obtains the current urea concentration C1 detected by the urea quality sensor. If both C0 and C1 are less than the urea concentration calibration value C... 标定 Then continue to report the previous driving cycle C. dmin If a fault is detected, the driver should be prompted to disconnect T15 and replace the urea solution with a suitable one. Otherwise, the system will automatically perform one Cdmin fault clearing action before starting the engine.

[0067] After the engine is started, the urea concentration acquisition module in the ECU unit detects and reads the urea concentration C1 in real time through the urea quality sensor (without filtering). At this time, the diagnostic window timer T0 in the ECU unit starts counting. When T0 reaches T... 标定 When urea concentration is low, it is included in the calculation of the percentage of time spent at low urea concentration; otherwise, it is not calculated. It should be noted that T... 标定 It can be modified appropriately according to the actual situation. The default setting is 1200s, which ensures that a fault is reported within one transient emission cycle.

[0068] At the same time, the comparison module compares the current urea concentration C1 with the urea concentration calibration value C in real time. 标定 If C1 is lower than C, then the comparison is made. 标定 If the urea concentration in the ECU unit is low, the T1 timer will start counting; otherwise, it will not count. It is important to emphasize that the T1 timer is an incrementing timer, and the urea concentration calibration value is C. 标定 The setting can be adjusted according to the actual use of the engine; the default setting is 25.5%.

[0069] When T0 = T 标定At that time, the ECU unit's percentage calculation module begins to calculate the percentage of time A when the urea concentration is low. 占 =T1 / T0, if A 占 Greater than or equal to the calibration value A for the proportion of time with low urea concentration 标定 The fault alarm module reports a low urea concentration fault; after reporting the fault, T0 and T1 are cleared to 0, and then the process continues to the next diagnostic window. If the low urea concentration time accounts for A... 占 The percentage of time with lower urea concentration than the calibration value A 标定 If the urea concentration is normal, the diagnosis is terminated and the urea will not be used for diagnosis again in this driving cycle.

[0070] It should be noted that the calibration value A represents the percentage of time with low urea concentration. 标定 This can be adjusted according to the engine; the default setting is 90%. It can be adjusted for low urea concentration time percentages (A). 占 The numerical values ​​indicate different severity levels of faults, and then different levels of protective measures are taken according to the fault level to ensure engine safety and reliability. For example, it can be set as: A 占 A failure rate of 95% or higher is considered extremely serious; A 占 A failure rate greater than 90% but less than 95% is considered a serious fault; A 占 A failure rate of 90% or less is considered a general fault, and different protection measures are adopted according to the fault registration.

[0071] Because this invention automatically performs a Cdmin fault clearing action once before the engine starts, regardless of the vehicle's operating environment, the fault is easily resolved. The urea concentration diagnosis method designed in this invention no longer uses filtering, but adopts a low concentration time ratio diagnosis logic within a large diagnostic window, which effectively improves the engine's ability to avoid low urea concentration caused by small bubbles.

[0072] The diagnostic strategy proposed in this embodiment, though simple, is ingeniously conceived and highly practical. It ensures the normal reporting of real faults within a single WHTC / NRTC cycle while effectively avoiding false alarms caused by bubble effects. Moreover, faults are difficult to report and easy to resolve, resulting in a good customer experience.

[0073] Furthermore, this embodiment also provides an electronic device for detecting urea concentration faults, including: at least one processor and a memory; the memory stores computer execution instructions; the at least one processor executes the computer execution instructions stored in the memory, causing the at least one processor to execute the aforementioned method for preventing false alarms in urea concentration.

[0074] The electronic device in this embodiment is represented in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processing unit, at least one storage unit, and a bus connecting different system components.

[0075] The storage unit stores program code, which can be executed by the processing unit to enable the processing unit to perform the method for preventing false alarms of urea concentration described in this embodiment.

[0076] The storage unit may include a readable medium in the form of volatile storage units, such as random access memory (RAM) and / or cache memory units, and may further include read-only memory (ROM). The storage unit may also include a program / utility having a set (at least one) of program modules 325; the bus may be one or more of several types of bus structures, including a storage unit bus or storage unit controller, peripheral bus, graphics acceleration port, processing unit, or a local bus using any of the various bus structures.

[0077] Electronic devices can also communicate with one or more external devices (such as keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable users to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (such as routers, modems, etc.). This communication can be achieved through input / output (I / O) interfaces. Furthermore, electronic devices can communicate with one or more networks (such as local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. As shown in the figure, the network adapter communicates with other modules of the electronic device via a bus.

[0078] According to the present invention, a computer-readable storage medium is also provided, on which a program product capable of implementing a diagnostic method for preventing false alarms in urea concentration is stored. In some possible embodiments, various aspects of the present invention can also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the present invention described in the "Exemplary Methods" section above.

[0079] refer to Figure 4The diagram illustrates a program product for implementing the above-described method according to an embodiment of the present invention. This program product may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. The program product may employ any combination of one or more readable media. The readable media may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0080] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0081] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0082] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0083] In summary, this application provides a method, apparatus, device, and storage medium for avoiding false alarms of abnormal urea concentration. The method includes the following steps: starting the engine; reading the current urea concentration value in real time, while simultaneously starting a diagnostic window timer; comparing the current urea concentration value with a calibrated urea concentration value in real time; if the current urea concentration value is lower than the calibrated urea concentration value, the low urea concentration timer starts timing; otherwise, it stops timing; when the diagnostic window timer reaches the calibrated time value, calculating the low urea concentration time percentage, where the low urea concentration time percentage is equal to the ratio of the time obtained by the low urea concentration timer to the calibrated time value; if the low urea concentration time percentage is greater than or equal to the calibrated low urea concentration time percentage, reporting a low urea concentration fault; if the low urea concentration time percentage is less than the calibrated low urea concentration time percentage, the urea concentration is normal, and the diagnostic process ends.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A diagnostic method for preventing false alarms in urea concentration, characterized in that, The method is as follows: Before starting the engine, the urea concentration of the previous driving cycle is retrieved and the current urea concentration is checked. If both concentrations are lower than the urea concentration calibration value, a low urea solution concentration fault of the previous driving cycle is reported, reminding the driver to disconnect the power and replace it with qualified urea solution. Otherwise, the low urea solution concentration fault is cleared, and then the engine is started. Engine start; The current urea concentration value is read in real time, and the diagnostic window timer starts counting down. The current urea concentration value is compared with the urea concentration calibration value in real time. If the current urea concentration value is lower than the urea concentration calibration value, the urea concentration low timer starts timing; otherwise, it does not start timing. The urea concentration low timer is an intermittent timer. When the diagnostic window timer reaches the time calibration value, the proportion of time with low urea concentration is calculated, where the proportion of time with low urea concentration is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value. If the percentage of time with low urea concentration is greater than or equal to the calibrated value, a low urea concentration fault is reported; if the percentage of time with low urea concentration is less than the calibrated value, the urea concentration is normal, and the diagnosis ends.

2. The diagnostic method for preventing false alarms in urea concentration as described in claim 1, characterized in that, The aforementioned percentage calibration value is set to different values ​​according to the fault level.

3. A diagnostic device for preventing false alarms about urea concentration, characterized in that, include: The fault prediction module is configured to retrieve the urea concentration of the previous driving cycle and check the current urea concentration before the engine starts. If both concentrations are lower than the urea concentration calibration value, a fault of low urea solution concentration in the previous driving cycle is reported, reminding the driver to disconnect the power and replace it with qualified urea solution. Otherwise, the fault of low urea solution concentration is cleared, and the engine is started. The urea concentration acquisition module is used to read the current urea concentration value in real time. The diagnostic window timer is used to time the detection process. The comparison module is used to compare the current urea concentration value with the urea concentration calibration value in real time. The urea concentration low timer is configured to start timing if the current urea concentration value is lower than the urea concentration calibration value, and not to start timing otherwise. The urea concentration low timer is an intermittent timer. The percentage calculation module is configured to calculate the percentage of time with low urea concentration when the diagnostic window timer reaches the time calibration value, where the percentage of time with low urea concentration is equal to the ratio of the time obtained by the low urea concentration timer to the time calibration value. The fault alarm module is configured to report a low urea concentration fault if the percentage of time with low urea concentration is greater than or equal to the calibrated value; if the percentage of time with low urea concentration is less than the calibrated value, the urea concentration is normal and no fault is reported.

4. The diagnostic device for preventing false alarms of urea concentration as described in claim 3, characterized in that, The aforementioned percentage calibration value is set to different values ​​according to the fault level.

5. An electronic device for detecting urea concentration faults, characterized in that, include: At least one processor and memory; The memory stores computer-executed instructions; The at least one processor executes computer execution instructions stored in the memory, causing the at least one processor to perform the diagnostic method for preventing false alarms of urea concentration as described in claim 1 or 2.

6. A readable storage medium, characterized in that, The readable storage medium stores computer-executable instructions, which, when executed by the processor, implement the method for preventing false alarms of urea concentration as described in claim 1 or 2.

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