A method, device and storage medium for diagnosing float fault of liquid level sensor

Abstract

The present invention relates to the field of sensor fault diagnosis technology, and in particular to a method, device and storage medium for diagnosing a liquid level sensor float fault. The method comprises the following steps: determining that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then entering a detection cycle; obtaining the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor during the detection cycle; if the cumulative urea injection amount of the urea nozzle reaches a preset cumulative consumption during the detection cycle, or if the urea filling amount reaches a preset limit and the filling is completed during the detection cycle, the detection cycle ends; obtaining the difference between the maximum liquid level value and the minimum liquid level value, and if the difference is less than a preset calibration value, determining that the liquid level sensor float is stuck. By comparing the difference between the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor with the preset calibration limit, determining that the liquid level sensor float is faulty, so that it is possible to determine whether the liquid level sensor float is faulty without disassembly.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor fault diagnosis, and in particular to a method, device and storage medium for diagnosing float fault of a liquid level sensor. Background Art

[0002] Abnormal urea consumption is largely caused by the urea tank float being stuck. When the urea level sensor float is stuck, the urea level displayed on the instrument cannot reflect the real urea level data, which will cause the actual level to be very low but cannot be discovered in time, leading to problems such as excessive emissions due to insufficient urea, and then causing the vehicle to be limited in torque and speed, affecting user driving. The level sensor is installed on the urea tank, and the float of the level sensor is in the urea tank. If you want to detect whether the float of the level sensor is stuck, you need to disassemble it for inspection, which makes the method of judging the stuck fault more troublesome.

[0003] Therefore, there is an urgent need for a liquid level sensor float fault diagnosis method to solve the above technical problems. Summary of the invention

[0004] The object of the present invention is to provide a method, device and storage medium for diagnosing a float fault of a liquid level sensor, which can determine whether the float of the liquid level sensor is faulty without disassembling the urea tank.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A method for diagnosing a float fault of a liquid level sensor comprises the following steps:

[0007] Make sure that the urea level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then enter the detection cycle;

[0008] Obtain the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor within the detection cycle;

[0009] If the cumulative urea injection amount of the urea nozzle reaches the preset cumulative consumption during the detection cycle, or if the urea filling amount reaches the preset limit and the filling is completed during the detection cycle, the detection cycle ends;

[0010] The difference between the maximum liquid level value and the minimum liquid level value is obtained. If the difference is less than the preset calibration value, it is determined that the float of the liquid level sensor is stuck.

[0011] As a preferred technical solution of the above-mentioned liquid level sensor float fault diagnosis method, obtaining the maximum liquid level value and the minimum liquid level value of the liquid level sensor within the detection cycle includes:

[0012] The urea liquid level value is obtained at a regular interval, and multiple urea liquid level values ​​obtained are compared within a detection period to determine the maximum liquid level value and the minimum liquid level value in the urea tank.

[0013] As a preferred technical solution of the above-mentioned liquid level sensor float fault diagnosis method, obtaining the maximum liquid level value and the minimum liquid level value of the liquid level sensor within the detection cycle includes:

[0014] At the beginning of a single detection cycle, a first urea liquid level value in the urea tank is obtained;

[0015] At the end of a single detection cycle, a second urea liquid level value in the urea tank is obtained;

[0016] Comparison is performed to determine that one of the first urea liquid level value and the second urea liquid level value is a minimum liquid level value and the other is a maximum liquid level value.

[0017] As a preferred technical solution of the above-mentioned method for diagnosing float fault of liquid level sensor, the preset cumulative consumption is the sum of the cumulative urea consumption at the beginning of the detection cycle and the preset increase.

[0018] As a preferred technical solution of the above-mentioned liquid level sensor float fault diagnosis method, within a single detection cycle, if the urea liquid level sensor is disconnected from the vehicle ECU or the urea nozzle is blocked, the detection cycle is terminated.

[0019] As a preferred technical solution of the above-mentioned method for diagnosing float fault of liquid level sensor, before entering the detection cycle, it also includes determining that the urea liquid level is within the calibration range.

[0020] As a preferred technical solution of the above-mentioned liquid level sensor float fault diagnosis method, if the liquid level sensor float is stuck, a fault is reported to remind the user to inspect the urea injection system.

[0021] A liquid level sensor float fault diagnosis device, comprising:

[0022] A first judgment module is used to determine that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked;

[0023] The first acquisition and calculation module is used to obtain the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor during the detection period and calculate the difference between the maximum liquid level value and the minimum liquid level value;

[0024] The second collection and calculation module is used to obtain whether the cumulative urea injection amount of the urea nozzle reaches a preset cumulative consumption amount and the urea filling amount reaches a preset limit;

[0025] The diagnostic module is used to diagnose that the float of the liquid level sensor is stuck when the difference between the maximum liquid level value and the minimum liquid level value is less than a preset calibration limit.

[0026] As a preferred technical solution of the above-mentioned liquid level sensor float fault diagnosis device, it also includes an alarm module, which is used to diagnose the liquid level sensor float stuck and delayed alarm fault in the diagnosis module to remind the user to repair the urea injection system.

[0027] An electronic device, comprising:

[0028] processor;

[0029] a memory for storing instructions executable by the processor;

[0030] Wherein, the processor is configured to execute the instructions to implement the liquid level sensor float fault diagnosis method described in any of the above schemes.

[0031] A storage medium stores a computer program, which, when executed by a processor, implements the method for diagnosing float faults of a liquid level sensor described in any of the above schemes.

[0032] Beneficial effects of the present invention:

[0033] By adopting the method for diagnosing the stuck float of the liquid level sensor provided in the present invention, the maximum liquid level value and the minimum liquid level value of the urea tank are detected by the liquid level sensor of the urea tank, and the factors affecting the diagnosis result are eliminated. The difference between the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor is compared with the preset calibration limit value to determine the float fault of the liquid level sensor. Therefore, it is possible to determine whether the float of the liquid level sensor is faulty without disassembling the urea tank, thereby improving the efficiency of fault judgment.

[0034] By adopting the liquid level sensor float fault diagnosis device provided in the present invention, the urea consumption at the urea nozzle can be detected, the maximum liquid level value and the minimum liquid level value of the urea tank can be detected by the liquid level sensor of the urea tank, and the factors affecting the diagnosis result can be eliminated. By comparing the difference between the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor with the preset calibration limit value, it is determined whether the liquid level sensor float is faulty, so that it is possible to judge whether the liquid level sensor float is faulty without disassembling it, thereby improving the fault judgment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0036] Figure 1 It is a main flow chart of the method for diagnosing float fault of a liquid level sensor provided by an embodiment of the present invention;

[0037] Figure 2 It is a detailed flow chart of the method for diagnosing a float fault of a liquid level sensor provided by an embodiment of the present invention when it is applied to a urea nozzle spraying urea;

[0038] Figure 3 It is a detailed flow chart of the method for diagnosing float fault of a liquid level sensor provided in an embodiment of the present invention when applied to urea filling. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0040] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0043] The liquid level sensor obtains the liquid level in the urea tank by causing the resistance value to change due to the float floating up and down. However, in the prior art, the float of the liquid level sensor can only be detected by disassembly, and the fault judgment method is relatively troublesome.

[0044] To this end, an embodiment of the present invention provides a method for diagnosing float faults of a liquid level sensor to solve the above technical problems.

[0045] like Figure 1 As shown, the method comprises the following steps:

[0046] S11, determining that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then entering a detection cycle;

[0047] Before executing the fault diagnosis method, it is necessary to determine whether the urea consumption has reached the preset consumption. By excluding the faults of other parts of the liquid level sensor except the float part, the urea liquid level sensor is not disconnected from the vehicle ECU, and the urea nozzle is not blocked, the accuracy of the detection can be improved to prevent inaccurate diagnosis due to other reasons. In addition, during diagnosis, it is necessary to determine that the urea liquid level is within the calibration range to prevent the liquid level from being too high or too low, causing a large error in the liquid level measurement and affecting the diagnosis result.

[0048] S12, obtaining the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor within the detection cycle;

[0049] Multiple liquid level values ​​of the liquid level sensor are obtained during the detection cycle, and the sizes of the multiple liquid level values ​​are compared to determine the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor. In this way, urea can be added to the urea tank during the detection cycle, and the added urea will not affect the detection.

[0050] S13: If the cumulative urea injection amount of the urea nozzle reaches a preset cumulative consumption amount during the detection period, or if the urea filling amount reaches a preset limit and the filling is completed during the detection period, the detection period ends;

[0051] By limiting the end adjustment, the method can be applied to the urea injection process as well as the urea addition process. When urea is added, the urea nozzle does not work, so the conditions for judging the end of the detection cycle are different for adding urea and injecting urea.

[0052] S14, obtaining the difference between the maximum liquid level value and the minimum liquid level value. If the difference is less than the preset calibration value, it is determined that the float of the liquid level sensor is stuck.

[0053] By comparing the difference between the maximum and minimum liquid level values ​​with the preset calibration limit, it is possible to determine whether the float of the liquid level sensor is stuck. Urea can be added to the urea tank during the detection cycle. If the float of the liquid level sensor is stuck after adding urea, the detected liquid level will be the same as the liquid level detected at the beginning. During the detection process, the same value can be assigned to the maximum and minimum liquid level values, which can also realize the diagnosis of whether the float is stuck.

[0054] The maximum and minimum liquid level values ​​can be obtained during driving. If urea shakes in the urea tank during driving, the maximum and minimum liquid level values ​​detected may not be the actual liquid level, but this detection does not affect the diagnosis result, because the embodiment of the present invention diagnoses whether the float is stuck, so whether urea is added or urea shakes, the diagnosis method provided in this embodiment will not cause diagnostic errors. In this way, the execution of the diagnostic method will not be affected by the addition of urea or the amount of urea injection.

[0055] By adopting the float stuck diagnosis method provided in this embodiment, the maximum liquid level value and the minimum liquid level value of the urea tank are detected by the liquid level sensor of the urea tank, and the factors affecting the diagnosis result are eliminated. The difference between the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor is compared with the preset calibration limit value to determine the float fault of the liquid level sensor. In this way, it is possible to determine whether the float of the liquid level sensor is faulty without disassembling the urea tank, thereby improving the efficiency of fault judgment.

[0056] Specifically, obtaining the maximum liquid level value and the minimum liquid level value of the liquid level sensor within the detection cycle includes: obtaining the urea liquid level value at regular intervals, and comparing the sizes of the multiple urea liquid level values ​​obtained within the detection cycle to determine the maximum liquid level value and the minimum liquid level value in the urea tank. That is, multiple urea liquid level values ​​are obtained within the detection cycle, and the multiple urea liquid level values ​​obtained will be compared after the detection cycle is about to end to obtain the maximum liquid level value and the minimum liquid level value. The maximum liquid level value may be obtained after urea is added, or it may be obtained after the urea tank is shaken. The minimum liquid level value may be obtained before urea is added, or it may be obtained after the urea tank is shaken. By obtaining the maximum liquid level value and the minimum liquid level value, it can be determined whether the float of the liquid level sensor is faulty.

[0057] Furthermore, when the vehicle is running smoothly and no urea is added, the maximum liquid level value and the minimum liquid level value are obtained at the beginning and end of the detection cycle, respectively. Therefore, at the beginning of a single detection cycle, it is necessary to obtain the urea liquid level value in the urea tank. At the end of a single detection cycle, obtain the urea liquid level value in the urea tank. In this way, under the premise that the urea nozzle sprays urea during the stable operation of the vehicle, the urea liquid level value at the beginning of a single detection cycle is the maximum value, and the urea liquid level value obtained at the end of a single detection cycle is the minimum value. When adding urea, the urea liquid level value at the beginning of a single detection cycle is the minimum value, and the urea liquid level value obtained at the end of a single detection cycle is the maximum value. In this way, the situation where the ECU has a large workload due to multiple detections can be avoided.

[0058] Furthermore, the preset cumulative consumption is the sum of the cumulative urea consumption at the beginning of the detection cycle and the preset increase. The current cumulative urea consumption (i.e., the preset cumulative consumption) is recorded as the initial value for recording the cumulative urea consumption of the next detection cycle. When the initial value of the cumulative urea consumption is 0, the preset cumulative consumption is the preset increase. It is understandable that the preset increase in each detection cycle is the same. It is understandable that, whether it is the first time the vehicle is used or after it has been used for a period of time, the float fault of the liquid level sensor is detected once every time the urea consumption increases by the preset increase, so as to prevent the float of the liquid level sensor from getting stuck during long-term use and affecting the injection of urea.

[0059] When the float of the liquid level sensor is detected to be stuck, the sensor will be reported as stuck by display, buzzer or light, which can remind the user to inspect the urea injection system. At the same time, it can accurately locate the fault point, so that the manual can quickly locate the fault point for repair, improving the efficiency of inspection and maintenance.

[0060] It should be noted that the time from the start of urea liquid level detection to the end of urea liquid level detection is the detection period, and the duration of the detection period is not particularly limited, which is specifically determined according to the preset cumulative consumption or the preset limit.

[0061] In addition, in a single detection cycle, if the urea level sensor is disconnected from the vehicle ECU or the urea nozzle is blocked, the detection cycle will be terminated. The detection cycle can only be entered after the fault is resolved.

[0062] Before entering the detection cycle, it is also necessary to confirm that the urea liquid level is within the calibration range. Confirming that the urea liquid level is within the calibration range is to prevent the occurrence of false alarms due to overfilling of the urea, and also to prevent the occurrence of false alarms below the zero scale of the urea.

[0063] In combination with the above-described process, the present invention provides a method for diagnosing float faults of a liquid level sensor. Figure 2 As shown, when the urea nozzle is sprayed, the method specifically includes:

[0064] S21, determining that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then entering a detection cycle;

[0065] S22, obtaining the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor within the detection cycle;

[0066] S23, if the cumulative urea injection amount of the urea nozzle reaches a preset cumulative consumption amount during the detection period, the detection period ends;

[0067] S24, calculating the difference between the maximum liquid level value and the minimum liquid level value;

[0068] S25, determine whether the difference is less than the preset calibration limit, if so, execute step S26, if not, execute step S27;

[0069] S26, determining that the float of the liquid level sensor is faulty, and notifying the user of the float fault of the liquid level sensor of the urea tank;

[0070] S27. Determine that the float of the liquid level sensor of the urea tank is not faulty.

[0071] During the urea injection process, since the end of the detection cycle is judged based on the cumulative urea injection amount of the urea nozzle reaching the preset cumulative consumption, urea can be added during the detection cycle. During the urea addition process, the float can be fault diagnosed or not. When the float is not fault diagnosed, the end of the detection cycle is based on the cumulative urea injection amount of the urea nozzle reaching the preset cumulative consumption.

[0072] Combination Figure 3 As shown, when urea is added, the method specifically comprises:

[0073] S31, determining that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then entering a detection cycle;

[0074] S32, obtaining the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor within the detection cycle;

[0075] S33. If the urea filling amount reaches the preset limit and the filling is completed within the detection period, the detection period ends;

[0076] S34, calculating the difference between the maximum liquid level value and the minimum liquid level value;

[0077] S35, determine whether the difference is less than the preset calibration limit, if so, execute step S36, if not, execute step S37;

[0078] S36, determining that the float of the liquid level sensor is faulty, and notifying the user of the float fault of the liquid level sensor of the urea tank;

[0079] S37. Determine that the float of the liquid level sensor of the urea tank is not faulty.

[0080] It should be noted that the urea filling amount reaches the preset limit and the filling is completed, which can be obtained through the diagnostic tool or after-sales service tool at the urea filling station.

[0081] The embodiment of the present invention also provides a liquid level sensor float fault diagnosis device, including a first judgment module, a first acquisition and calculation module, a second acquisition and calculation module and a diagnosis module. The first judgment module is used to determine that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked; the first acquisition and calculation module is used to obtain the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor during the detection cycle and calculate the difference between the maximum liquid level value and the minimum liquid level value; the second acquisition and calculation module is used to obtain the cumulative urea injection amount of the urea nozzle reaching the preset cumulative consumption and the urea filling amount reaching the preset limit; the diagnosis module is used to determine that when the difference between the maximum liquid level value and the minimum liquid level value is less than the preset calibration limit, the liquid level sensor float is diagnosed to be stuck.

[0082] Optionally, the liquid level sensor float fault diagnosis device further comprises a warning module, and the warning module is used to report a fault after determining that the liquid level sensor float is stuck, so as to remind the user to inspect the urea injection system.

[0083] By using the liquid level sensor float fault diagnosis device provided in this embodiment, the urea consumption at the urea nozzle can be detected, the maximum liquid level value and the minimum liquid level value of the urea tank can be detected by the liquid level sensor of the urea tank, and the factors affecting the diagnosis result can be eliminated. By comparing the difference between the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor with the preset calibration limit, it is determined whether the liquid level sensor float is faulty, so that it is possible to determine whether the liquid level sensor float is faulty without disassembling it, thereby improving the fault diagnosis efficiency.

[0084] An embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein the memory is used to store program codes used when the electronic device is running; and the processor is used to execute the program codes to implement a float fault judgment method for a liquid level sensor.

[0085] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframes, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0086] The "electronic device" in the embodiments of the present invention refers to any device that can run according to a program and automatically and quickly process large amounts of data, including mobile phones, mobile robots, computers, tablets, smart terminals, multimedia devices, streaming media devices, etc.

[0087] The electronic device specifically includes components such as a power supply, a processor, a memory and a display unit.

[0088] The memory can be used to store software programs and modules. The processor executes various functional applications and data processing of the electronic device by running the software programs and modules stored in the memory, and when the processor executes the program code in the memory, part or all of the process in the float fault diagnosis method of the liquid level sensor of the present invention can be implemented.

[0089] Optionally, the memory may mainly include a program storage area and a data storage area. The program storage area may store an operating system, various application programs (such as communication applications), and a face recognition module, etc.; the data storage area may store data created according to the use of the terminal (such as various multimedia files such as pictures and video files, and face information templates), etc.

[0090] In addition, the memory may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0091] The display unit can be used to display information input by the user or information provided to the user and various menus of the electronic device. The display unit is the display system of the electronic device, which is used to present the interface and realize human-computer interaction. For example, it can display float fault information.

[0092] The display unit may include a display panel. Optionally, the display panel may be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like.

[0093] The processor is the control center of the electronic device. It uses various interfaces and lines to connect various components, and executes various functions of the electronic device and processes data by running or executing software programs and / or modules stored in the memory, and calling data stored in the memory, thereby realizing a variety of terminal-based services.

[0094] The processor may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of processors include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 11 executes the various methods and processes described above, such as a liquid level sensor float fault diagnosis method.

[0095] Optionally, the processor may include one or more processing units. Optionally, the processor may integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the modem processor may not be integrated into the processor.

[0096] The electronic device also includes a power source (such as a battery) for supplying power to each component. Optionally, the power source can be logically connected to the processor through a power management system, so that the power management system can manage functions such as charging, discharging, and power consumption.

[0097] Since the electronic device implements the above-mentioned method for diagnosing float faults of a liquid level sensor, the electronic device of the embodiment of the present invention has all the advantages and beneficial effects of the above-mentioned embodiments, which will not be described in detail here.

[0098] The embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for diagnosing a float fault of a liquid level sensor provided in the embodiment of the present invention are executed, and the method is applied to the robot provided in the embodiment of the present invention. The method includes:

[0099] Make sure that the urea level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then enter the detection cycle;

[0100] Obtain the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor within the detection cycle;

[0101] If the cumulative urea injection amount of the urea nozzle reaches the preset cumulative consumption during the detection cycle, or if the urea filling amount reaches the preset limit and the filling is completed during the detection cycle, the detection cycle ends;

[0102] The difference between the maximum liquid level value and the minimum liquid level value is obtained. If the difference is less than the preset calibration value, it is determined that the float of the liquid level sensor is stuck.

[0103] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0104] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0105] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0106] The computer program code for performing the operation of the embodiment of the present invention can be written in one or more programming languages ​​or a combination thereof, and the programming language includes an object-oriented programming language, such as Java, Smalltalk, C++, and also includes a conventional procedural programming language, such as "C" language or similar programming language. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., using an Internet service provider to connect through the Internet).

[0107] In addition, the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for diagnosing float faults of a liquid level sensor, characterized in that: The steps include: Make sure that the urea level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked, then enter the detection cycle; Obtain the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor within the detection cycle; If the cumulative urea injection amount of the urea nozzle reaches the preset cumulative consumption during the detection cycle, or if the urea filling amount reaches the preset limit and the filling is completed during the detection cycle, the detection cycle ends; Obtain the difference between the maximum liquid level value and the minimum liquid level value. If the difference is less than the preset calibration value, it is determined that the float of the liquid level sensor is stuck. Obtaining the maximum and minimum liquid level values ​​of the liquid level sensor within the detection cycle includes: Obtaining urea liquid level values ​​at regular intervals, and comparing multiple urea liquid level values ​​obtained within a detection period to determine the maximum liquid level value and the minimum liquid level value in the urea tank; During the test cycle, urea is added to the urea tank, and the added urea will not affect the test; When the vehicle is running smoothly, the maximum and minimum liquid level values ​​of the liquid level sensor obtained during the detection cycle include: At the beginning of a single detection cycle, a first urea liquid level value in the urea tank is obtained; At the end of a single detection cycle, a second urea liquid level value in the urea tank is obtained; Comparing and determining that one of the first urea liquid level value and the second urea liquid level value is a minimum liquid level value and the other is a maximum liquid level value; The preset cumulative consumption is the sum of the cumulative urea consumption at the beginning of the detection cycle and the preset increase.

2. The method for diagnosing float fault of a liquid level sensor according to claim 1, characterized in that: During a single detection cycle, if the urea liquid level sensor is disconnected from the vehicle ECU or the urea nozzle is clogged, the detection cycle is terminated.

3. The method for diagnosing float fault of a liquid level sensor according to claim 1, characterized in that: Before entering the detection cycle, it also includes confirming that the urea liquid level is within the calibration range.

4. The method for diagnosing float fault of a liquid level sensor according to claim 1, characterized in that: If the float of the liquid level sensor is stuck, a fault will be reported to remind the user to inspect the urea injection system.

5. A liquid level sensor float fault diagnosis device, characterized in that: Used to perform the float fault diagnosis method of the liquid level sensor according to any one of claims 1 to 4, the device comprises: A first judgment module is used to determine that the urea liquid level sensor is not disconnected from the vehicle ECU and the urea nozzle is not blocked; The first acquisition and calculation module is used to obtain the maximum liquid level value and the minimum liquid level value detected by the liquid level sensor during the detection period and calculate the difference between the maximum liquid level value and the minimum liquid level value; The second collection and calculation module is used to obtain whether the cumulative urea injection amount of the urea nozzle reaches a preset cumulative consumption amount and the urea filling amount reaches a preset limit; The diagnostic module is used to diagnose that the float of the liquid level sensor is stuck when the difference between the maximum liquid level value and the minimum liquid level value is less than a preset calibration limit.

6. The liquid level sensor float fault diagnosis device according to claim 5, characterized in that: It also includes an alarm module, which is used to diagnose the delayed alarm fault of the liquid level sensor float card in the diagnosis module to remind the user to inspect the urea injection system.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the float fault diagnosis method of the liquid level sensor as described in any one of claims 1 to 4 is implemented.

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