Diesel engine urea concentration diagnosis method, device, equipment, medium and product

Abstract

The invention relates to the technical field of diesel engines, and discloses a diesel engine urea concentration diagnosis method, device and equipment, a medium and a product. Searching whether a normal urea concentration value is detected in the last driving cycle or not, wherein the driving cycle represents the process of the vehicle from power-on to power-off or ignition to flameout; detecting whether to inject urea according to the urea liquid level of the urea box; if the normal urea concentration value is detected in the last driving cycle and urea is not injected, the normal urea concentration value serves as the current urea concentration value to be output. The urea concentration detection accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engines, and in particular to a method, device, equipment, medium and product for diagnosing urea concentration of a diesel engine. Background Art

[0002] With the increasingly stringent emission regulations, for diesel engines, in addition to strict control of engine emissions, it is also necessary to use new off-board post-processing purification technology to control and treat emission pollutants. Among the common post-processing, the SCR (Selective Catalytic Reduction) system is the most commonly used, and the SCR system needs to spray urea solution into the exhaust gas to eliminate the harmful component NOx in the exhaust gas through chemical reactions. Emission regulations have set requirements for the concentration of urea solution to prevent users from using inferior urea or other solutions as substitutes. This requires the post-processing control system to be able to diagnose whether the urea solution used by the user meets the requirements. Ultrasonic urea quality sensor is a means of detecting urea concentration. The urea concentration is calculated based on the ultrasonic voltage amplitude signal and echo time of the ultrasonic urea quality sensor. However, due to the different attenuation degrees of ultrasonic waves in different media, when there are bubbles in urea, the ultrasonic voltage amplitude signal and echo time obtained by detection change, and the detection results will directly affect the final urea concentration. In actual application, engineering machinery such as loaders will frequently move and change during operation, and the solution in the urea tank will vibrate, inevitably generating bubbles. Among them, tiny bubbles are very easy to adhere to the ultrasonic urea quality sensor. Once a large number of tiny bubbles adhere to the ultrasonic urea quality sensor for a long time, it will directly lead to the distortion of the obtained urea concentration. Summary of the invention

[0003] In view of this, the present invention provides a method, device, equipment, medium and product for diagnosing urea concentration in a diesel engine to solve the problem of inaccurate urea concentration detection.

[0004] In a first aspect, the present invention provides a method for diagnosing urea concentration of a diesel engine, the method comprising: powering on or igniting a vehicle; searching whether a normal urea concentration value is detected in the last driving cycle, the driving cycle representing a process from powering on to powering off or from ignition to shutting down of the vehicle; detecting whether urea is added according to the urea liquid level of a urea tank; if a normal urea concentration value is detected in the last driving cycle and urea is not added, outputting the normal urea concentration value as the current urea concentration value.

[0005] In some optional embodiments, if a normal urea concentration value is detected in the last driving cycle and urea is not added, the normal urea concentration value is output as the current urea concentration value, including: taking the normal urea concentration value as the current urea concentration value and locking the output under the condition that urea is not added.

[0006] In some optional implementations, the method further includes: if a normal urea concentration value is detected in the previous driving cycle and urea is added, unlocking the output urea value; re-detecting the urea concentration and judging whether the new urea concentration is qualified; if the new urea concentration value is qualified, locking and outputting the new urea concentration value without further adding urea; if the new urea concentration value is unqualified, outputting the new urea concentration and urea warning information.

[0007] In some optional implementations, the method further includes: if no normal urea concentration value is detected in the last driving cycle and urea is not added, detecting the real-time urea concentration value; judging whether the real-time urea concentration value is qualified; if the real-time urea concentration value is qualified, locking and outputting the real-time urea concentration value; if the real-time urea concentration value is unqualified, clearing the last locked value, and outputting the real-time urea concentration value and urea warning information.

[0008] In some optional implementations, the method further includes: if the normal urea concentration value is not detected in the previous driving cycle and urea is added, unlocking the output urea value; re-detecting the urea concentration and judging whether the new urea concentration is qualified; if the new urea concentration value is qualified, locking and outputting the new urea concentration value without further adding urea; if the new urea concentration value is unqualified, outputting the new urea concentration and urea warning information.

[0009] In some optional embodiments, the step of judging whether the current urea concentration is qualified includes: detecting whether the urea liquid level is stable for more than a first preset time; when the urea liquid level is stable for more than the first preset time, judging whether the current urea concentration is within a preset urea concentration range; if the current urea concentration is within the preset urea concentration range, determining that it is qualified; if the current urea concentration is not within the preset urea concentration range, determining that it is unqualified.

[0010] In some optional embodiments, detecting whether to add urea based on the urea liquid level of the urea tank includes: judging whether the urea liquid level rises by a preset height within a second preset time; if the urea liquid level rises by the preset height within the second preset time, determining that urea is added; if the urea liquid level does not rise by the preset height within the second preset time, determining that urea is not added.

[0011] In a second aspect, the present invention provides a diesel engine urea concentration diagnostic device, the device comprising: a vehicle power-on module, used for powering on or igniting a vehicle; a historical urea concentration reading module, used for searching whether a normal urea concentration value is detected in the last driving cycle, the driving cycle representing a process from power-on to power-off or from ignition to shutdown of the vehicle; a filling judgment module, used for detecting whether urea is added according to the urea liquid level of a urea tank; and a historical concentration use module, used for outputting the normal urea concentration value as the current urea concentration value if a normal urea concentration value is detected in the last driving cycle and urea is not added.

[0012] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0013] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to cause a computer to execute the method of the first aspect or any corresponding embodiment thereof.

[0014] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the method of the first aspect or any corresponding embodiment thereof.

[0015] The technical solution provided by the present invention does not first detect the real-time urea concentration in each driving cycle when urea is not added, but first searches whether there is a normal urea concentration value in the previous driving cycle. As long as there is a normal urea concentration value in the previous driving cycle, the normal urea concentration value of the previous driving cycle is directly output as the urea concentration value of the current driving cycle when urea is not added. The current driving cycle detects the real-time urea concentration only when urea is added in the current driving cycle or there is no normal urea concentration value in the previous driving cycle. Through this solution, it is assumed that the concentration of urea will not change with normal urea consumption. As long as a normal value can be detected once in the historical time, it means that the urea concentration is normal, and then the normal urea concentration is continuously output, which can significantly avoid the problem of inaccurate sensor collection caused by bubbles and improve the accuracy of urea concentration collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a schematic flow chart of a method for diagnosing urea concentration in a diesel engine according to an embodiment of the present invention;

[0018] Figure 2 is a schematic flow chart of a method for diagnosing urea concentration in a diesel engine according to an embodiment of the present invention;

[0019] Figure 3 is a schematic structural diagram of a diesel engine urea concentration diagnostic device according to an embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0022] According to an embodiment of the present invention, an embodiment of a method for diagnosing urea concentration in a diesel engine is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0023] In this embodiment, a method for diagnosing urea concentration in a diesel engine is provided. Figure 1 : is a flow chart of a method for diagnosing urea concentration in a diesel engine according to an embodiment of the present invention, the flow chart comprising the following steps:

[0024] Step S101, the vehicle is powered on or ignited;

[0025] Step S102, searching whether a normal urea concentration value is detected in the last driving cycle, where the driving cycle refers to the process from power-on to power-off or from ignition to shutdown of the vehicle;

[0026] Step S103, detecting whether to add urea according to the urea liquid level in the urea tank;

[0027] Step S104: if a normal urea concentration value is detected in the last driving cycle and urea is not added, the normal urea concentration value is output as the current urea concentration value.

[0028] Specifically, a driving cycle refers to a complete process from power-on to power-off or from ignition to flameout of a vehicle. Related technologies often periodically perform multiple urea concentration tests in a driving cycle. After the vehicle is powered on, the embodiment of the present invention first searches whether a normal urea concentration value is detected in the previous driving cycle, that is, if multiple urea concentration tests are performed in the previous driving cycle, the embodiment of the present invention determines whether at least one urea concentration detected meets the qualified condition. Furthermore, as long as at least one normal urea concentration value is detected in the previous driving cycle, and urea is not added in the current driving cycle, it can be assumed that the normal consumption of urea in the current driving cycle will not change in concentration. As long as a normal value can be detected once in the historical time, it means that the urea concentration is normal, and then the normal urea concentration detected in the previous driving cycle is output in the current driving cycle, and the real-time detected urea concentration is no longer output. Similarly, if the concentration value of the previous driving cycle is qualified, the previous driving cycle can directly output the normal value of the previous driving cycle. This solution can significantly avoid the problem of inaccurate sensor data collection caused by urea bubbles, thereby improving the accuracy of urea concentration collection.

[0029] In some optional implementations, the above step S104 includes:

[0030] Step a1: taking the normal urea concentration value as the current urea concentration value and locking the output under the condition that urea is not added.

[0031] Specifically, when the embodiment of the present invention detects that the previous driving cycle has a normal urea concentration value, it not only outputs the normal urea concentration value, but also locks the normal urea concentration value and continues to output it in the current driving cycle without adding urea, and no new real-time urea concentration detection is performed subsequently, which not only avoids the urea concentration error caused by bubbles and improves the detection accuracy, but also reduces the number of detections and improves the computing power of the vehicle processor.

[0032] In some optional embodiments, the method further comprises:

[0033] Step b1, if a normal urea concentration value is detected in the last driving cycle and urea is added, the output urea value is unlocked;

[0034] Step b2, re-testing the urea concentration and determining whether the new urea concentration is qualified;

[0035] Step b3: if the new urea concentration value is qualified, the new urea concentration value is locked and outputted without further adding urea;

[0036] Step b4: if the new urea concentration value is unqualified, the new urea concentration and urea warning information are output.

[0037] Step b5: if the normal urea concentration value is not detected in the last driving cycle and urea is added, the output urea value is unlocked;

[0038] Step b6, re-detecting the urea concentration and determining whether the new urea concentration is qualified;

[0039] Step b7, if the new urea concentration value is qualified, the new urea concentration value is locked and outputted without further adding urea;

[0040] Step b8: If the new urea concentration value is unqualified, the new urea concentration and urea warning information are output.

[0041] Specifically, the urea liquid level will change during normal consumption and refilling, but the liquid level change caused by normal urea consumption will not cause the urea concentration to change, so re-detection is often not required during normal consumption. In the embodiment of the present invention, if the liquid level of the urea solution is detected to have changed, and it is determined based on the liquid level that urea is refilled in the current driving cycle, the probability of causing the urea concentration to change is very high. At this time, regardless of whether a normal urea concentration value is detected in the previous driving cycle, re-detection should be performed. In the embodiment of the present invention, when urea is refilled, the urea concentration is re-detected and it is determined whether the new urea concentration is qualified, for example, it is specifically determined whether the urea concentration is around 32.5%, for example, whether it is within the range of 32.5%±5.5%. If it is within the range, the urea concentration is qualified, otherwise it is unqualified. The automotive urea contains 32.5% high-purity urea and 67.5% deionized water. The automotive urea concentration refers to the ratio of urea to deionized water. Usually, the automotive urea concentration is qualified within the range of 32.5% ± 0.7. This embodiment defines ± 5.5% to more broadly accept the influence of urea caused by bubbles and reduce the false alarm rate. This embodiment only takes ± 5.5% as an example, and is not limited to this. The specific value range can be adjusted according to user needs.

[0042] Afterwards, if the embodiment of the present invention determines that the re-tested new urea concentration value is qualified, the new urea concentration value can be locked and outputted if urea is not added subsequently, and the re-test is continued if urea is added. If the embodiment of the present invention determines that the new urea concentration value is unqualified, the new urea concentration and urea alarm information are outputted to notify the user to promptly check the problem and replace the new urea solution completely.

[0043] In some optional embodiments, the method further comprises:

[0044] Step c1, if the normal urea concentration value is not detected in the last driving cycle and urea is not added, then the real-time urea concentration value is detected;

[0045] Step c2, judging whether the real-time urea concentration value is qualified;

[0046] Step c3, if the real-time urea concentration value is qualified, lock and output the real-time urea concentration value;

[0047] Step c4: if the real-time urea concentration value is unqualified, the last locked value is cleared, and the real-time urea concentration value and urea alarm information are output.

[0048] Specifically, it is assumed that urea is not added in the current driving cycle, but the search in the current driving cycle finds that no normal urea concentration value was detected in the previous driving cycle. In view of this situation, in order to further improve the reliability of detection and avoid false alarms in historical detection, this embodiment still needs to detect the urea concentration value in real time in the current driving cycle and determine whether it is qualified. If the real-time urea concentration value detected this time is qualified, the real-time urea concentration value can be locked and output, and the real-time urea concentration value detected this time is used as the normal value for the next driving cycle. Otherwise, the normal value locked in the previous driving cycle is cleared, and the real-time urea concentration value and urea warning information just detected are output, and the user is notified to promptly check the problem and replace the new urea solution.

[0049] In some optional embodiments, the step of judging whether the current urea concentration is qualified includes:

[0050] Step d1, detecting whether the urea liquid level is stable for more than a first preset time;

[0051] Step d2, when the urea liquid level is stable for more than the first preset time, determining whether the current urea concentration is within the preset urea concentration range;

[0052] Step d3: if the current urea concentration is within the preset urea concentration range, it is determined to be qualified;

[0053] Step d4: if the current urea concentration is not within the preset urea concentration range, it is determined to be unqualified.

[0054] Specifically, when the present invention detects whether the urea concentration is qualified, it is first necessary to determine whether the urea liquid level has been in a stable and unchanged state for more than a first preset time, for example, to determine whether the urea liquid level has been in a stable and unchanged state for more than 30 seconds. If the urea liquid level has been in a stable and unchanged state for more than the first preset time, it can be determined that urea has not been added temporarily, and the urea concentration is relatively stable at this time, and detection can be started. Then, it is determined whether the current urea concentration is within the preset urea concentration range, for example, it is determined whether the urea concentration is within the interval of 32.5%±5.5%. If it is within the above interval, it is determined that the urea is qualified, otherwise it is determined to be unqualified. Through the technical solution provided by this embodiment, the influence of the liquid level change during the filling process on the urea concentration detection is further reduced, and the accuracy of the urea concentration detection is improved.

[0055] In some optional implementation manners, the above step S103 includes:

[0056] Step e1, determining whether the urea liquid level rises to a preset height within a second preset time;

[0057] Step e2, if the urea liquid level rises to a preset height within the second preset time, determining to add urea;

[0058] Step e3: if the urea liquid level does not rise to the preset height within the second preset time, it is determined that urea is not added.

[0059] Specifically, the scheme for detecting whether urea is added in the embodiment of the present invention is determined by the urea liquid level rising to a preset height within a second preset time, wherein the preset height may be a predefined fixed height value or a preset proportion of the maximum liquid level value. For example, if the urea liquid level rises by 20% or more of the maximum liquid level value within 2 minutes, it is confirmed that urea has been added, otherwise, it is determined that urea has not been added. The embodiment of the present invention identifies the urea addition situation through the two conditions of the change height and change time of the urea liquid level, further improving the recognition accuracy of the urea addition scene.

[0060] In a complete embodiment, the method for diagnosing urea concentration in a diesel engine provided by the present invention is as follows: Figure 2 As shown, the following steps are included:

[0061] 100. The vehicle is powered on or ignited;

[0062] 200. Search whether the last driving cycle detected a normal urea concentration value. The driving cycle refers to the process from power on to power off or from ignition to shutdown of the vehicle.

[0063] 300. Check whether to add urea according to the urea liquid level in the urea tank;

[0064] 400. If a normal urea concentration value is detected in the last driving cycle and urea is not added, the normal urea concentration value is used as the current urea concentration value;

[0065] 401. Lock the output without further adding urea.

[0066] 500. If a normal urea concentration value is detected in the last driving cycle and urea is added, the output urea value is unlocked;

[0067] 501. Re-test the urea concentration and determine whether the new urea concentration is qualified;

[0068] 502. If the new urea concentration value is qualified, the new urea concentration value is locked and outputted without further adding urea;

[0069] 503. If the new urea concentration value is unqualified, the new urea concentration and urea alarm information are output.

[0070] 600. If the normal urea concentration value is not detected in the last driving cycle and urea is not added, the real-time urea concentration value is detected;

[0071] 601. Determine whether the real-time urea concentration value is qualified;

[0072] 602. If the real-time urea concentration value is qualified, the real-time urea concentration value is locked and output;

[0073] 603. If the real-time urea concentration value is unqualified, the previous lock value is cleared, and the real-time urea concentration value and urea alarm information are output.

[0074] 700. If the normal urea concentration value was not detected in the last driving cycle and urea was added, the output urea value is unlocked;

[0075] 701. Re-test the urea concentration and determine whether the new urea concentration is qualified;

[0076] 702. If the new urea concentration value is qualified, the new urea concentration value is locked and outputted without further adding urea;

[0077] 703. If the new urea concentration value is unqualified, the new urea concentration and urea alarm information are output.

[0078] In this embodiment, a diesel engine urea concentration diagnostic device is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0079] This embodiment provides a diesel engine urea concentration diagnostic device, such as Figure 3 As shown, including:

[0080] The vehicle power-on module 301 is used to power on or ignite the vehicle;

[0081] The historical urea concentration reading module 302 is used to search whether a normal urea concentration value is detected in the last driving cycle, and the driving cycle represents the process from power-on to power-off or from ignition to shutdown of the vehicle;

[0082] A filling judgment module 303 is used to detect whether to add urea according to the urea liquid level of the urea tank;

[0083] The historical concentration use module 304 is used to output the normal urea concentration value as the current urea concentration value if a normal urea concentration value is detected in the last driving cycle and urea is not added.

[0084] In some optional implementations, the historical concentration use module 304 includes:

[0085] The locking output unit is used to take the normal urea concentration value as the current urea concentration value and lock the output under the condition that urea is not added.

[0086] In some optional embodiments, the device further comprises:

[0087] A first unlocking unit is used to unlock the output urea value if a normal urea concentration value is detected in the last driving cycle and urea is added;

[0088] A first re-testing unit, used to re-test the urea concentration and determine whether the new urea concentration is qualified;

[0089] The first output unit is used for locking and outputting the new urea concentration value if the new urea concentration value is qualified without further adding urea;

[0090] The second output unit is used to output the new urea concentration and urea warning information if the new urea concentration value is unqualified.

[0091] In some optional embodiments, the device further comprises:

[0092] A first real-time detection unit is used to detect a real-time urea concentration value if a normal urea concentration value is not detected in the last driving cycle and urea is not added;

[0093] The first qualified detection unit is used to determine whether the real-time urea concentration value is qualified;

[0094] A third output unit is used to lock and output the real-time urea concentration value if the real-time urea concentration value is qualified;

[0095] The fourth output unit is used to clear the last locked value and output the real-time urea concentration value and urea warning information if the real-time urea concentration value is unqualified.

[0096] In some optional embodiments, the device further comprises:

[0097] A second unlocking unit is used to unlock the output urea value if the normal urea concentration value is not detected in the last driving cycle and urea is added;

[0098] The second re-testing unit is used to re-test the urea concentration and determine whether the new urea concentration is qualified;

[0099] The fifth output unit is used for locking and outputting the new urea concentration value if the new urea concentration value is qualified without further adding urea;

[0100] The sixth output unit is used to output the new urea concentration and urea warning information if the new urea concentration value is unqualified.

[0101] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0102] The diesel engine urea concentration diagnostic device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0103] The embodiment of the present invention also provides a computer device having the above Figure 3 The diesel engine urea concentration diagnostic device is shown.

[0104] See also Figure 4 , Figure 4 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 4As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 4 A processor 10 is taken as an example.

[0105] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0106] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0107] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0108] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0109] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0110] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0111] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0112] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for diagnosing urea concentration in a diesel engine, characterized in that: The method comprises: The vehicle is powered on or ignited; Searching whether a normal urea concentration value is detected in the last driving cycle, wherein the driving cycle represents a process from power-on to power-off or ignition to shutdown of the vehicle; Check whether to add urea according to the urea level in the urea tank; If a normal urea concentration value is detected in the last driving cycle and urea is not added, the normal urea concentration value is output as the current urea concentration value.

2. The method according to claim 1, characterized in that If a normal urea concentration value is detected in the last driving cycle and urea is not added, the normal urea concentration value is output as the current urea concentration value, including: The normal urea concentration value is used as the current urea concentration value, and the output is locked under the condition that urea is not added.

3. The method according to claim 2, characterized in that The method further comprises: If a normal urea concentration value is detected in the last driving cycle and urea is added, the output urea value is unlocked; Re-test the urea concentration and determine whether the new urea concentration is qualified; If the new urea concentration value is qualified, the new urea concentration value is locked and outputted without further adding urea; If the new urea concentration value is unqualified, the new urea concentration and urea warning information are output.

4. The method according to claim 2, characterized in that: The method further comprises: If the normal urea concentration value is not detected in the last driving cycle and urea is not added, the real-time urea concentration value is detected; Determining whether the real-time urea concentration value is qualified; If the real-time urea concentration value is qualified, locking and outputting the real-time urea concentration value; If the real-time urea concentration value is unqualified, the last locked value is cleared, and the real-time urea concentration value and urea warning information are output.

5. The method according to claim 2, characterized in that: The method further comprises: If the normal urea concentration value was not detected in the last driving cycle and urea was added, the output urea value is unlocked; Re-test the urea concentration and determine whether the new urea concentration is qualified; If the new urea concentration value is qualified, the new urea concentration value is locked and outputted without further adding urea; If the new urea concentration value is unqualified, the new urea concentration and urea warning information are output.

6. The method according to any one of claims 3 to 5, characterized in that: The steps of judging whether the current urea concentration is qualified include: Detecting whether the urea liquid level is stable for more than a first preset time; When the urea liquid level is stable for more than the first preset time, determining whether the current urea concentration is within a preset urea concentration range; If the current urea concentration is within the preset urea concentration range, it is determined to be qualified; If the current urea concentration is not within the preset urea concentration range, it is determined to be unqualified.

7. The method according to claim 1, characterized in that The step of detecting whether to add urea according to the urea liquid level of the urea tank includes: Determining whether the urea liquid level rises by a preset height within a second preset time; If the urea liquid level rises by the preset height within the second preset time, it is determined that urea needs to be added; If the urea liquid level does not rise to the preset height within the second preset time, it is determined that urea is not added.

8. A diesel engine urea concentration diagnostic device, characterized in that: The device comprises: Vehicle power-on module, used for powering on or igniting the vehicle; A historical urea concentration reading module is used to search whether a normal urea concentration value is detected in the last driving cycle, wherein the driving cycle represents a process from power-on to power-off or from ignition to shutdown of the vehicle; A filling judgment module is used to detect whether to add urea according to the urea liquid level in the urea tank; The historical concentration use module is used to output the normal urea concentration value as the current urea concentration value if a normal urea concentration value is detected in the previous driving cycle and urea is not added.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 7.

Images