Urea quality detection method and device and vehicle

Abstract

The invention is suitable for the technical field of vehicles, and provides a urea quality detection method and device and a vehicle. The method comprises the steps that whether a urea quality signal detected by a urea quality sensor in the vehicle is effective or not is judged according to the environment temperature; if the urea quality signal is invalid, acquiring nitrogen and oxygen detection data of a nitrogen and oxygen sensor in the vehicle and urea filling information within preset time; and detecting the urea quality according to the nitrogen and oxygen detection data and the urea filling information. Whether the urea quality signal detected by the urea quality sensor is effective is judged according to the environment temperature. When the urea quality signal is invalid, the urea quality is judged according to the nitrogen and oxygen detection data and the urea filling information within the preset time. Nitrogen and oxygen detection data can reflect the tail gas treatment level and indirectly reflect the urea quality, and by combining urea filling information, misjudgment and missed judgment caused by low environment temperature or sensor faults can be effectively avoided, the accuracy of urea quality detection is improved, and the false alarm and missed alarm probability of a vehicle is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to a urea quality detection method, device and vehicle. Background Art

[0002] With the continuous development of society, environmental protection has become an issue that people are increasingly concerned about. In the field of vehicles, nitrogen oxides in diesel vehicle exhaust can cause environmental pollution. In related technologies, in order to reduce nitrogen oxide pollution in diesel vehicle exhaust, most diesel models are equipped with urea systems to neutralize nitrogen oxides in exhaust. At the same time, in order to ensure qualified emissions, the urea concentration in the urea aqueous solution must meet the national standard concentration requirement of 32.5%, so urea quality detection has become an important functional requirement in the urea system.

[0003] However, the accuracy of urea quality detection is affected by many factors. For example, when the temperature is too low, floating ice in the urea aqueous solution will interfere with the urea quality detection, causing the urea concentration detected by the urea sensor to be substandard; when the sensor fails, it will also produce incorrect quality detection results. All of the above situations may lead to missed reports or false reports, affecting the normal operation of the vehicle. Summary of the invention

[0004] In view of this, the embodiments of the present invention provide a urea quality detection method, device and vehicle to more accurately determine whether the urea quality is qualified and reduce the probability of false alarms and missed alarms.

[0005] A first aspect of an embodiment of the present invention provides a urea quality detection method, comprising:

[0006] Get the current ambient temperature;

[0007] determining, according to the ambient temperature, whether a urea quality signal detected by a urea quality sensor in the vehicle is valid;

[0008] If the urea quality signal is invalid, obtaining nitrogen oxygen detection data of a nitrogen oxygen sensor in the vehicle and urea filling information within a preset time;

[0009] The urea quality is detected according to the nitrogen oxide detection data and the urea filling information.

[0010] In combination with the first aspect, in a possible implementation of the first aspect, detecting urea quality according to the nitrogen oxide detection data and the urea filling information includes:

[0011] According to the nitrogen oxide detection data, it is judged whether the nitrogen oxide emission in the tail gas exceeds the standard, and if the nitrogen oxide emission does not exceed the standard, it is determined that the urea quality is qualified;

[0012] If the nitrogen oxide emission exceeds the standard, judging whether urea has been added to the vehicle within the preset time according to the urea filling information;

[0013] If urea has been added to the vehicle within the preset time, it is determined that the quality of the urea is unqualified.

[0014] In combination with the first aspect, in a possible implementation of the first aspect, after determining, according to the urea filling information, whether urea has been added to the vehicle within the preset time, the method further includes:

[0015] If urea has not been added to the vehicle within the preset time, it is determined that the nitrogen oxide sensor or the post-treatment system is faulty, and the vehicle is controlled to display a first alarm signal.

[0016] In combination with the first aspect, in a possible implementation of the first aspect, the urea filling information includes a urea filling door switch signal;

[0017] The determining, based on the urea filling information, whether urea has been added to the vehicle within the preset time includes:

[0018] If the urea filling door switch signal shows that the urea filling door is opened within the preset time, it is determined that urea has been added to the vehicle within the preset time.

[0019] In combination with the first aspect, in a possible implementation manner of the first aspect, after judging whether a urea quality signal detected by a urea quality sensor in the vehicle is valid according to the ambient temperature, the method further includes:

[0020] If the urea quality signal is valid, acquiring the urea quality signal and nitrogen oxygen detection data of a nitrogen oxygen sensor in the vehicle;

[0021] The urea quality is detected according to the urea quality signal and the nitrogen oxide detection data.

[0022] In combination with the first aspect, in a possible implementation of the first aspect, detecting urea quality according to the urea quality signal and the nitrogen oxide detection data includes:

[0023] If the urea quality signal indicates that the urea quality is qualified, determining that the urea quality is qualified;

[0024] If the urea quality signal shows that the urea quality is unqualified, judging whether the nitrogen oxide emission in the tail gas exceeds the standard according to the nitrogen oxide detection data;

[0025] If the nitrogen oxide emission does not exceed the standard, the urea quality is determined to be qualified;

[0026] If the nitrogen oxide emission exceeds the standard, it is determined that the urea quality is unqualified.

[0027] In combination with the first aspect, in a possible implementation of the first aspect, after judging whether the nitrogen oxide emission in the exhaust gas exceeds the standard according to the nitrogen oxide detection data, the method further includes:

[0028] If the nitrogen oxide emission does not exceed the standard, it is determined that the urea quality sensor is faulty, and the vehicle is controlled to display a second alarm signal.

[0029] In combination with the first aspect, in a possible implementation of the first aspect, judging whether a urea quality signal detected by a urea quality sensor in the vehicle is valid according to the ambient temperature includes:

[0030] If the ambient temperature is greater than or equal to a preset temperature threshold, it is determined that the urea quality signal is valid;

[0031] If the ambient temperature is less than the temperature threshold, it is determined that the urea quality signal is invalid.

[0032] A second aspect of an embodiment of the present invention provides a urea quality detection device, comprising:

[0033] The acquisition module is used to obtain the current ambient temperature;

[0034] A judging module, used for judging whether a urea quality signal detected by a urea quality sensor in the vehicle is valid according to the ambient temperature;

[0035] The processing module is used for acquiring nitrogen oxide detection data of a nitrogen oxide sensor in the vehicle and urea filling information within a preset time if the urea quality signal is invalid; and detecting urea quality according to the nitrogen oxide detection data and the urea filling information.

[0036] In conjunction with the second aspect, in a possible implementation manner of the second aspect, the processing module is specifically configured to:

[0037] According to the nitrogen oxide detection data, it is judged whether the nitrogen oxide emission in the tail gas exceeds the standard, and if the nitrogen oxide emission does not exceed the standard, it is determined that the urea quality is qualified;

[0038] If the nitrogen oxide emission exceeds the standard, judging whether urea has been added to the vehicle within the preset time according to the urea filling information;

[0039] If urea has been added to the vehicle within the preset time, it is determined that the quality of the urea is unqualified.

[0040] In combination with the second aspect, in a possible implementation of the second aspect, after determining, according to the urea filling information, whether urea has been added to the vehicle within the preset time, the processing module is further configured to:

[0041] If urea has not been added to the vehicle within the preset time, it is determined that the nitrogen oxide sensor or the post-treatment system is faulty, and the vehicle is controlled to display a first alarm signal.

[0042] In combination with the second aspect, in a possible implementation manner of the second aspect, the urea filling information includes a urea filling door switch signal;

[0043] The processing module is specifically used for:

[0044] If the urea filling door switch signal shows that the urea filling door is opened within the preset time, it is determined that urea has been added to the vehicle within the preset time.

[0045] In combination with the second aspect, in a possible implementation of the second aspect, after judging whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature, the processing module is further used to:

[0046] If the urea quality signal is valid, acquiring the urea quality signal and nitrogen oxygen detection data of a nitrogen oxygen sensor in the vehicle;

[0047] The urea quality is detected according to the urea quality signal and the nitrogen oxide detection data.

[0048] In conjunction with the second aspect, in a possible implementation manner of the second aspect, the processing module is specifically configured to:

[0049] If the urea quality signal indicates that the urea quality is qualified, determining that the urea quality is qualified;

[0050] If the urea quality signal shows that the urea quality is unqualified, judging whether the nitrogen oxide emission in the tail gas exceeds the standard according to the nitrogen oxide detection data;

[0051] If the nitrogen oxide emission does not exceed the standard, the urea quality is determined to be qualified;

[0052] If the nitrogen oxide emission exceeds the standard, it is determined that the urea quality is unqualified.

[0053] In combination with the second aspect, in a possible implementation of the second aspect, if the nitrogen oxide emission does not exceed the standard, the processing module is further used to:

[0054] The urea quality sensor is determined to be faulty, and the vehicle is controlled to display a second warning signal.

[0055] In conjunction with the second aspect, in a possible implementation manner of the second aspect, the determination module is specifically configured to:

[0056] If the ambient temperature is greater than or equal to a preset temperature threshold, it is determined that the urea quality signal is valid;

[0057] If the ambient temperature is less than the temperature threshold, it is determined that the urea quality signal is invalid.

[0058] A third aspect of an embodiment of the present invention provides a vehicle, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method in the first aspect or any one of the implementations of the first aspect are implemented.

[0059] A fourth aspect of an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a controller, it implements the steps of the method in the above-mentioned first aspect or any one of the implementation methods of the first aspect.

[0060] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0061] Since the urea quality sensor will produce detection errors when the ambient temperature is low, the embodiment of the present invention does not directly judge the urea quality based on the urea quality signal, but first judges whether the urea quality signal detected by the urea quality sensor is valid based on the ambient temperature. When the urea quality signal is invalid, the nitrogen oxygen detection data of the nitrogen oxygen sensor in the vehicle and the urea filling information within a preset time are obtained. Among them, the nitrogen oxygen detection data can reflect the treatment level of the exhaust gas and indirectly reflect the urea quality. This embodiment combines the urea filling information to comprehensively judge the urea quality, which can effectively avoid misjudgment and missed judgment caused by low ambient temperature or sensor failure, improve the accuracy of urea quality detection, and reduce the probability of false alarms and missed alarms of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 these drawings without paying creative labor.

[0063] Figure 1 Schematic diagram of an application scenario of a urea quality inspection method provided by an embodiment of the present invention;

[0064] Figure 2The following is a schematic diagram of the implementation process of the urea quality inspection method provided in the embodiment of the present invention. Figure 1 ;

[0065] Figure 3 The following is a schematic diagram of the implementation process of the urea quality inspection method provided in the embodiment of the present invention. Figure 2 ;

[0066] Figure 4 The following is a schematic diagram of the implementation process of the urea quality inspection method provided in the embodiment of the present invention. Figure 3 ;

[0067] Figure 5 It is a structural schematic diagram of a urea quality inspection device provided in an embodiment of the present invention;

[0068] Figure 6 It is a schematic diagram of the structure of a vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0069] The present application is described more clearly below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the effects of the present application, but are not intended to limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present application. These all fall within the scope of protection of the present application.

[0070] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0071] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0072] In the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0073] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0074] In addition, the “plurality” mentioned in the embodiments of the present application should be interpreted as two or more.

[0075] Current measures to reduce nitrogen oxides (NO x The mainstream measure for emission reduction is to install a selective catalytic reduction system (SCR) behind the engine exhaust pipe. That is, under the action of the catalyst inside the SCR catalyst, NO x It reacts with the reducing agent ammonia (NH3) to convert into nitrogen (N2) and water (H2O) to effectively reduce NO x The most common source of reducing agent NH3 is urea aqueous solution, so the quality of urea aqueous solution has a great impact on the NO emission of SCR system. x It has a significant impact on conversion rate.

[0076] In the related art, urea quality sensors are often used to detect the quality of urea aqueous solution in vehicles, where quality usually refers to concentration. The principles of urea quality sensors include: specific heat capacity principle, acoustic principle, optical principle, etc. Among them, the market utilization rate of urea quality sensors based on the specific heat capacity principle is relatively low, so they will not be introduced here. The acoustic principle can be divided into two types. One is similar to the principle of a tuning fork densitometer, that is, the structure of the element is equivalent to a two-tooth tuning fork. The fork body vibrates due to the piezoelectric crystal at the root of the fork, and the frequency of the vibration is detected by the piezoelectric crystal located on the other fork finger. Through phase shifting and circuit amplification and processing, the fork body is stabilized at the natural frequency. When the medium flows through the fork body, it causes a change in the resonant frequency, which is converted into a measurement of the solubility of the solution. The other is based on the different speeds of ultrasonic waves in different media. By measuring the time taken for the emission and reflection reception of the sound wave signal within a fixed distance, the speed of sound in the liquid is measured to obtain the concentration of the urea aqueous solution. The optical principle is to use the refraction phenomenon when light propagates at the interface of different media. When the urea concentration changes, the refractive index will also change. By establishing the relationship between the automotive urea concentration and the refractive index of light, that is, based on the different refractive indices of light at different urea concentrations, the concentration of the urea aqueous solution can be detected.

[0077] The freezing point of standard urea aqueous solution is about -11°C. In some cold regions, it is common for users to add low-freezing-point urea. Because low-freezing-point urea aqueous solution contains more additives, according to the principle of urea quality sensor, there may be misjudgment of low-freezing-point urea aqueous solution. The engine fault light of some vehicles is associated with the detection results of urea quality sensor. If the urea quality sensor misjudges, the engine fault light will be directly lit, causing the whole vehicle to falsely report a fault. In addition, when the urea quality sensor fails, it may also lead to misjudgment or missed judgment. Therefore, there is an urgent need for a more accurate strategy to detect urea quality.

[0078] Figure 1 The schematic diagram of the application scenario of the urea quality detection method provided by the embodiment of the present invention includes: a controller, a display device, and also includes sensing devices such as a temperature sensor, a urea quality sensor, and a nitrogen oxide sensor.

[0079] The controller here is used to execute the urea quality detection method, including receiving data, data processing, sending execution commands, etc. The controller can be an independent controller or a vehicle controller. In this embodiment, a vehicle controller is used. The vehicle controller (VCU) is the core control unit of the vehicle, responsible for coordinating and managing the various subsystems of the vehicle to ensure the normal operation and efficient performance of the vehicle. As an information control center, the vehicle controller communicates and exchanges data with other automotive subsystems (such as SCR system, battery management system, etc.) through the controller area network (CAN) bus, such as receiving the urea filling door switch signal in the SCR system to achieve the coordinated work of various parts of the vehicle. The vehicle controller can monitor the operating status of each subsystem in real time, detect and diagnose faults, and alarm in time to ensure driving safety.

[0080] The display device can be the vehicle's instrument panel or multimedia screen. The display device and the vehicle controller communicate via the CAN bus to ensure efficient transmission and processing of information. For example, when the vehicle controller detects an abnormal vehicle status, it will display the fault information on the instrument panel to remind the driver to handle it in time. This design improves driving safety and convenience.

[0081] In this embodiment, the urea quality sensor can not only detect the urea concentration, but also measure the liquid level and temperature. All this information is transmitted to the vehicle controller via the CAN bus so that the vehicle controller can adjust the operation of the post-processing system according to real-time data. For example, when the urea liquid level is lower than a certain level, the vehicle will sound an alarm to remind the driver to replenish urea in time.

[0082] A nitrogen oxygen sensor is a device used to detect NO in engine exhaust. x It is a device that measures NO in exhaust gas and is widely used in automobile exhaust emission control systems and environmental monitoring. x The nitrogen oxide sensor is usually composed of a sensor probe, a control module, a connecting plug and a connecting cable. The core components of the nitrogen oxide sensor include a ceramic sensitive component and a control unit. The ceramic sensitive component contains a variety of ceramic inner cavities and conductive slurries, and the production process is complex. The working principle of the nitrogen oxide sensor is based on electrochemical reaction. It uses the conductivity of yttrium-doped zirconium oxide ceramic materials to detect oxygen ions, and combines special NO x Sensitive electrode materials to NO x Gas-specific selective catalytic sensitivity, ultimately converting NO xThe gas is detected and converted into a standard CAN bus digital signal. The nitrogen oxide sensor communicates with the vehicle controller or SCR system via the CAN bus. It has an internal self-diagnosis system that can detect nitrogen oxide concentrations and monitor its own working status.

[0083] In this application scenario, the nitrogen oxide sensor detects NO in the engine exhaust. x The urea quality sensor detects urea concentration, liquid level and temperature. These data are sent to the vehicle controller through the CAN bus. The vehicle controller also receives the urea filling door switch signal. The vehicle controller detects the urea quality by analyzing these data. When the urea quality is unqualified, an alarm signal can be generated and sent to the display device. The display device will alarm according to the alarm signal, such as lighting the engine fault light.

[0084] Combine the following Figure 1 For application scenarios, refer to Figure 2 To describe the urea quality detection method provided according to the exemplary embodiment of the present application. It should be noted that the above application scenarios are only shown to facilitate understanding of the spirit and principle of the present application, and the embodiments of the present application are not limited in this regard. On the contrary, the embodiments of the present application can be applied to any applicable scenario.

[0085] Combine the following Figure 2 As shown, the method of this embodiment is described in detail:

[0086] Step S201, obtaining the current ambient temperature.

[0087] In this embodiment, the vehicle detects the ambient temperature through a temperature sensor and sends it to the vehicle controller through the CAN bus. In order to ensure that the detected ambient temperature is consistent with the temperature of the urea aqueous solution, the ambient temperature should be the temperature outside the vehicle rather than the temperature inside the vehicle. Therefore, the temperature sensor should be installed outside the vehicle, preferably at the urea tank.

[0088] Step S202: judging whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature.

[0089] Floating ice in the low-freezing-point urea aqueous solution will interfere with the concentration measurement of the urea tank sensor, causing the urea concentration detected by the urea quality sensor to be substandard. Therefore, in this embodiment, when the ambient temperature is lower than a certain temperature threshold, the urea quality signal is considered unreliable.

[0090] The temperature threshold here can be set reasonably, and this embodiment does not make any specific limitation. For example, in this embodiment, the temperature threshold is 8°C, that is:

[0091] If the ambient temperature is greater than or equal to 8°C, the urea quality signal is determined to be valid;

[0092] If the ambient temperature is less than 8°C, the urea quality signal is determined to be invalid.

[0093] Step S203: if the urea quality signal is invalid, then obtaining the nitrogen oxide detection data of the nitrogen oxide sensor in the vehicle and the urea filling information within a preset time.

[0094] In this embodiment, when the urea quality signal is invalid, the nitrogen oxygen detection data of the nitrogen oxygen sensor in the vehicle and the urea filling information within a preset time are obtained.

[0095] Exemplarily, the urea filling information may be a urea filling door switch signal, which may be a signal input by a user to control the opening or closing of the urea filling door, or may be a signal detected by a sensor disposed at the urea filling door. For example, when the urea filling information is a urea filling door switch signal, when the urea filling door switch signal is at a high level, it is determined that the urea filling door is opened, and when the urea filling door switch signal is at a low level, it is determined that the urea filling door is closed.

[0096] The nitrogen oxide detection data can be the concentration of nitrogen oxides. The working principle of the nitrogen oxide sensor is based on the oxygen ion conductivity in the chemical reaction. When the sensor is exposed to an oxygen-rich environment, oxygen ions pass through the oxygen ion conductor layer of the sensor to the inside, where they react with NO x A chemical reaction occurs, generating electrons. These electrons are transmitted through the sensor's electrodes to form a current signal. Based on the size of this current signal, the NO in the engine exhaust can be determined. x concentration.

[0097] The preset time may be a period of time before the current time, such as 10 minutes or 20 minutes before the current time, and may be set according to actual needs, and is not specifically limited in this embodiment. The nitrogen and oxygen detection data and urea filling information are sent to the vehicle controller via the CAN bus for processing.

[0098] Step S204, detecting urea quality according to nitrogen oxide detection data and urea filling information.

[0099] Because nitrogen oxide detection data can reflect the treatment level of exhaust gas and indirectly reflect the quality of urea, and urea filling information can reflect the situation of urea filling in the recent period, the combination of the two can comprehensively judge the quality of urea and avoid misjudgment.

[0100] Exemplarily, the step may include:

[0101] Step S2041, judging whether the nitrogen oxide emission in the tail gas exceeds the standard according to the nitrogen oxide detection data, if the nitrogen oxide emission does not exceed the standard, it is determined that the urea quality is qualified.

[0102] Generally, when the urea quality is qualified, the nitrogen oxide emission in the tail gas will not exceed the standard. Therefore, if the nitrogen oxide emission does not exceed the standard, it can be determined that the urea quality is qualified. In addition, even if the urea quality is unqualified, as long as the nitrogen oxide emission does not exceed the standard, there is no need to deal with it, so it can be considered that the urea quality is qualified and no fault alarm is issued.

[0103] Step S2042: If the nitrogen oxide emission exceeds the standard, it is determined whether urea has been added to the vehicle within a preset time based on the urea filling information.

[0104] When nitrogen oxide emissions exceed the standard, it is usually considered that the urea quality is unqualified. In order to avoid misjudging the nitrogen oxide emissions caused by nitrogen oxide sensor failure and post-treatment system failure as excessive nitrogen oxide emissions caused by unqualified urea quality, further confirmation is performed by judging whether urea has been added to the vehicle within a preset time based on urea filling information.

[0105] For example, if the urea filling door switch signal shows that the urea filling door is open at the preset time, it is determined that urea has been added to the vehicle within the preset time. It is understandable that the original urea quality in the vehicle has been tested and qualified, and there will be no sudden changes. Only after the new urea is added, the nitrogen oxide emissions may exceed the standard due to the unqualified quality of the newly added urea.

[0106] Step S2043: if urea has been added to the vehicle within a preset time, it is determined that the urea quality is unqualified.

[0107] By making a comprehensive judgment based on whether nitrogen oxide emissions exceed the standard and whether urea has been added to the vehicle within the preset time, it can effectively avoid misjudging other fault conditions as unqualified urea quality, improve the accuracy of urea quality, and detect other sensor and post-treatment system faults to a certain extent.

[0108] For example, in some embodiments, it may also include:

[0109] Step S2044: if urea has not been added to the vehicle within a preset time, it is determined that the nitrogen oxide sensor or the post-treatment system is faulty, and the vehicle is controlled to display a first alarm signal.

[0110] The first alarm signal may be a fault indicator light on an instrument screen or a multimedia screen. By controlling the vehicle to display the first alarm signal, the user can be prompted to find and handle the fault in time. In addition, in this embodiment, when it is determined that the urea quality is unqualified, the relevant fault indicator light on the instrument screen or the multimedia screen can be controlled to light up to prompt the user that the quality of the urea added is unqualified.

[0111] Since the urea quality sensor will produce detection errors when the ambient temperature is low, the embodiment of the present invention does not directly judge the urea quality based on the urea quality signal, but first judges whether the urea quality signal detected by the urea quality sensor is valid based on the ambient temperature. When the urea quality signal is invalid, the nitrogen oxygen detection data of the nitrogen oxygen sensor in the vehicle and the urea filling information within a preset time are obtained. The nitrogen oxygen detection data can reflect the treatment level of the exhaust gas and indirectly reflect the urea quality. Combined with the urea filling information, the urea quality can be comprehensively judged, which can effectively avoid misjudgment and missed judgment caused by low ambient temperature or sensor failure, improve the accuracy of urea quality detection, and reduce the probability of false alarms and missed alarms of the vehicle.

[0112] The above embodiment is a processing flow when the ambient temperature is less than the temperature threshold and the urea quality signal detected by the urea quality sensor in the vehicle is judged to be invalid. When the ambient temperature is greater than or equal to the temperature threshold and the urea quality signal detected by the urea quality sensor in the vehicle is judged to be valid, this embodiment also provides a more accurate urea quality detection method. This is described by the following embodiments.

[0113] See also Figure 3 As shown, including:

[0114] Step S301, obtaining the current ambient temperature.

[0115] In this embodiment, the vehicle detects the ambient temperature through a temperature sensor and sends it to the vehicle controller through the CAN bus. In order to ensure that the detected ambient temperature is consistent with the temperature of the urea aqueous solution, the ambient temperature should be the temperature outside the vehicle rather than the temperature inside the vehicle. Therefore, the temperature sensor should be installed outside the vehicle, preferably at the urea tank.

[0116] Step S302: judging whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature.

[0117] Floating ice in the low-freezing-point urea aqueous solution will interfere with the concentration measurement of the urea tank sensor, causing the urea concentration detected by the urea quality sensor to be substandard. Therefore, in this embodiment, when the ambient temperature is lower than a certain temperature threshold, the urea quality signal is considered unreliable.

[0118] The temperature threshold here can be set reasonably, and this embodiment does not make any specific limitation. For example, in this embodiment, the temperature threshold is 8°C, that is:

[0119] If the ambient temperature is greater than or equal to 8°C, the urea quality signal is determined to be valid;

[0120] If the ambient temperature is less than 8°C, the urea quality signal is determined to be invalid.

[0121] Step S303: if the urea quality signal is valid, the urea quality signal and the nitrogen oxide detection data of the nitrogen oxide sensor in the vehicle are obtained; and the urea quality is detected according to the urea quality signal and the nitrogen oxide detection data.

[0122] Here, because the urea quality signal is credible, if the urea quality signal shows that the urea quality is qualified, it can be directly determined that the urea quality is qualified. The urea quality sensor can test the urea concentration during low-frequency and high-frequency vibration tests to maintain a stable urea quality signal output. In order to meet the emission requirements of vehicle exhaust emissions, the urea concentration should be greater than a certain urea concentration threshold, and the urea concentration threshold here can be determined according to relevant standards. When the urea concentration is greater than the urea concentration threshold, a urea quality signal indicating that the urea quality is qualified is output. When the urea concentration is less than the urea concentration threshold, a urea quality signal indicating that the urea quality is unqualified is output.

[0123] If the urea quality signal shows that the urea quality is unqualified, in order to avoid misjudgment caused by a nitrogen oxide sensor failure, the urea quality can be confirmed by further judging whether the nitrogen oxide emissions in the exhaust gas exceed the standard based on the nitrogen oxide detection data.

[0124] Right now:

[0125] If the nitrogen oxide emission does not exceed the standard, the urea quality is determined to be qualified;

[0126] If the nitrogen oxide emissions exceed the standard, it is determined that the urea quality is unqualified.

[0127] At the same time, if the nitrogen oxide emissions do not exceed the standard, it can also be determined that the urea quality sensor is faulty and the vehicle can be controlled to display a second alarm signal.

[0128] The second alarm signal may be a fault indicator light on an instrument screen or a multimedia screen. By controlling the vehicle to display the second alarm signal, the user can be prompted to find and handle the fault in time. In addition, in this embodiment, when it is determined that the urea quality is unqualified, the relevant fault indicator light on the instrument screen or the multimedia screen may be controlled to light up to prompt the user that the quality of the urea added is unqualified.

[0129] Comprehensive detection of urea quality through urea quality signal and nitrogen oxide detection data can avoid misjudgment caused by nitrogen oxide sensor failure and effectively improve the accuracy of urea quality detection.

[0130] For ease of understanding, Figure 4 The above two embodiments provide a schematic diagram of the overall implementation process of a urea quality detection method, including:

[0131] (1) The vehicle is powered on and the ambient temperature is continuously monitored.

[0132] (2) Determine whether the ambient temperature is greater than or equal to 8°C.

[0133] If the ambient temperature is greater than or equal to 8° C., the urea quality signal is determined to be valid, and the process goes to step (3); if the ambient temperature is less than 8° C., the urea quality signal is determined to be invalid, and the process goes to step (4).

[0134] (3) Determine whether the urea quality is qualified.

[0135] Here, the urea quality signal is used to determine whether the urea quality is qualified. Because the urea quality signal is reliable, if the urea quality signal shows that the urea quality is qualified, it can be directly determined that the urea quality is qualified, and the vehicle continues to be tested.

[0136] If the urea quality signal shows that the urea quality is unqualified, it is determined whether the nitrogen oxide emission exceeds the standard. If the nitrogen oxide emission does not exceed the standard, the urea quality is determined to be qualified, and at the same time, the urea quality sensor is determined to be faulty, and the vehicle can be controlled to display a second alarm signal to prompt the user; if the nitrogen oxide emission exceeds the standard, the urea quality is determined to be unqualified. When the urea quality is determined to be unqualified, the relevant fault indicator light on the instrument screen or the multimedia screen can be controlled to light up to prompt the user that the quality of the urea added is unqualified.

[0137] (4) Determine whether nitrogen oxide emissions exceed the standard.

[0138] If the nitrogen oxide emission does not exceed the standard, then based on the urea filling information, it is determined whether urea has been added to the vehicle within the preset time. If urea has been added to the vehicle within the preset time, it is determined that the urea quality is unqualified, and the relevant fault indicator light on the instrument screen or multimedia screen is controlled to light up to prompt the user that the quality of the added urea is unqualified. If urea has not been added to the vehicle within the preset time, it is determined that the urea quality is qualified, and at the same time, it is determined that the nitrogen oxide sensor or the post-processing system is faulty, and the vehicle can be controlled to display a first alarm signal to prompt the user. Among them, the first alarm signal and the second alarm signal can be set to different forms, for example, the first alarm signal is a nitrogen oxide sensor or post-processing system fault alarm light, and the second alarm signal is a urea quality sensor fault alarm light, so as to distinguish faults.

[0139] In the case where the urea quality signal is valid, this embodiment adds an auxiliary judgment of whether the nitrogen oxide emission is qualified compared with the traditional direct detection scheme for the urea quality problem, which can reduce the probability of false alarm of urea quality failure; in the case where the urea quality signal is invalid, whether the nitrogen oxide emission exceeds the standard and whether urea is added can be used to determine whether there is a urea quality failure and other fault sources, which can improve the reliability of the whole vehicle. This embodiment improves the accuracy of urea quality.

[0140] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0141] Figure 5 1 is a schematic diagram of the structure of a urea quality detection device 50 provided in an embodiment of the present invention. For details not included therein, please refer to the descriptions in the above-mentioned various method embodiments.

[0142] See also Figure 5 As shown, the urea quality detection device 50 includes:

[0143] The acquisition module 51 is used to acquire the current ambient temperature.

[0144] The judging module 52 is used to judge whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature.

[0145] The processing module 53 is used for obtaining the nitrogen oxygen detection data of the nitrogen oxygen sensor in the vehicle and the urea filling information within a preset time if the urea quality signal is invalid; and detecting the urea quality according to the nitrogen oxygen detection data and the urea filling information.

[0146] As a possible implementation manner, the processing module 53 is specifically used for:

[0147] According to the nitrogen oxide test data, determine whether the nitrogen oxide emission in the tail gas exceeds the standard. If the nitrogen oxide emission does not exceed the standard, it is determined that the urea quality is qualified;

[0148] If the nitrogen oxide emission exceeds the standard, it is determined whether urea has been added to the vehicle within the preset time based on the urea filling information;

[0149] If urea has been added to the vehicle within the preset time, it is determined that the urea quality is unqualified.

[0150] As a possible implementation, after determining whether urea has been added to the vehicle within a preset time according to the urea filling information, the processing module 53 is further configured to:

[0151] If urea has not been added to the vehicle within a preset time, it is determined that the nitrogen oxide sensor or the post-treatment system is faulty, and the vehicle is controlled to display a first alarm signal.

[0152] As a possible implementation, the urea filling information includes a urea filling door switch signal;

[0153] The processing module 53 is specifically used for:

[0154] If the urea filling door switch signal shows that the urea filling door is opened within the preset time, it is determined that urea has been added to the vehicle within the preset time.

[0155] As a possible implementation manner, after determining whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature, the processing module 53 is further used to:

[0156] If the urea quality signal is valid, the urea quality signal and the nitrogen oxide detection data of the nitrogen oxide sensor in the vehicle are obtained;

[0157] The urea quality is detected based on the urea quality signal and nitrogen oxide detection data.

[0158] As a possible implementation manner, the processing module 53 is specifically used for:

[0159] If the urea quality signal shows that the urea quality is qualified, it is determined that the urea quality is qualified;

[0160] If the urea quality signal shows that the urea quality is unqualified, the nitrogen oxide emission in the tail gas is judged to be excessive based on the nitrogen oxide detection data;

[0161] If the nitrogen oxide emission does not exceed the standard, the urea quality is determined to be qualified;

[0162] If the nitrogen oxide emissions exceed the standard, it is determined that the urea quality is unqualified.

[0163] As a possible implementation, if the nitrogen oxide emission does not exceed the standard, the processing module 53 is further used to:

[0164] The urea quality sensor is determined to be faulty, and the vehicle is controlled to display a second warning signal.

[0165] As a possible implementation manner, the determination module 52 is specifically configured to:

[0166] If the ambient temperature is greater than or equal to the preset temperature threshold, the urea quality signal is determined to be valid;

[0167] If the ambient temperature is less than the temperature threshold, the urea quality signal is determined to be invalid.

[0168] Since the urea quality sensor will produce detection errors when the ambient temperature is low, the embodiment of the present invention does not directly judge the urea quality based on the urea quality signal, but first judges whether the urea quality signal detected by the urea quality sensor is valid based on the ambient temperature. When the urea quality signal is invalid, the nitrogen oxygen detection data of the nitrogen oxygen sensor in the vehicle and the urea filling information within a preset time are obtained. The nitrogen oxygen detection data can reflect the treatment level of the exhaust gas and indirectly reflect the urea quality. Combined with the urea filling information, the urea quality can be comprehensively judged, which can effectively avoid misjudgment and missed judgment caused by low ambient temperature or sensor failure, improve the accuracy of urea detection, and reduce the probability of false alarms and missed alarms of the vehicle.

[0169] Figure 6 FIG. 6 is a schematic diagram of a vehicle 60 provided in one embodiment of the present invention. Figure 6 As shown, the vehicle 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61, such as a urea quality detection program. When the processor 61 executes the computer program 63, the steps in the above-mentioned urea quality detection method embodiments are implemented, such as Figure 2 Alternatively, when the processor 61 executes the computer program 63, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 5 The functions of modules 51 to 53 are shown.

[0170] Exemplarily, the computer program 63 may be divided into one or more modules / units, which are stored in the memory 62 and executed by the processor 61 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program 63 in the vehicle 60. For example, the computer program 63 may be divided into an acquisition module 51, a judgment module 52, and a processing module 53 (modules in a virtual device), and the specific functions of each module are as follows:

[0171] The acquisition module 51 is used to acquire the current ambient temperature.

[0172] The judging module 52 is used to judge whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature.

[0173] The processing module 53 is used for obtaining the nitrogen oxygen detection data of the nitrogen oxygen sensor in the vehicle and the urea filling information within a preset time if the urea quality signal is invalid; and detecting the urea quality according to the nitrogen oxygen detection data and the urea filling information.

[0174] The vehicle 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will appreciate that Figure 6 It is only an example of the vehicle 60 and does not constitute a limitation of the vehicle 60. The vehicle 60 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the vehicle 60 may also include input and output devices, network access devices, buses, etc.

[0175] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0176] The memory 62 may be an internal storage unit of the vehicle 60, such as a hard disk or memory of the vehicle 60. The memory 62 may also be an external storage device of the vehicle 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the vehicle 60. Further, the memory 62 may include both an internal storage unit and an external storage device of the vehicle 60. The memory 62 is used to store the computer program and other programs and data required by the vehicle 60. The memory 62 may also be used to temporarily store data that has been output or is to be output.

[0177] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0178] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0179] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0180] In the embodiments provided by the present invention, it should be understood that the disclosed devices / vehicles and methods can be implemented in other ways. For example, the device / vehicle embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0181] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0182] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0183] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0184] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A urea quality detection method, characterized in that: include: Get the current ambient temperature; determining, according to the ambient temperature, whether a urea quality signal detected by a urea quality sensor in the vehicle is valid; If the urea quality signal is invalid, obtaining nitrogen oxygen detection data of a nitrogen oxygen sensor in the vehicle and urea filling information within a preset time; The urea quality is detected according to the nitrogen oxide detection data and the urea filling information.

2. The urea quality detection method according to claim 1, characterized in that: The detecting of urea quality according to the nitrogen oxide detection data and the urea filling information includes: According to the nitrogen oxide detection data, judging whether the nitrogen oxide emission in the tail gas exceeds the standard; If the nitrogen oxide emission does not exceed the standard, the urea quality is determined to be qualified; If the nitrogen oxide emission exceeds the standard, it is determined whether urea has been added to the vehicle within the preset time based on the urea filling information; if urea has been added to the vehicle within the preset time, it is determined that the urea quality is unqualified.

3. The urea quality detection method according to claim 2, characterized in that: After determining whether urea has been added to the vehicle within the preset time according to the urea filling information, the method further includes: If urea has not been added to the vehicle within the preset time, it is determined that the nitrogen oxide sensor or the post-treatment system is faulty, and the vehicle is controlled to display a first alarm signal.

4. The urea quality detection method according to claim 2, characterized in that: The urea filling information includes a urea filling door switch signal; The determining, based on the urea filling information, whether urea has been added to the vehicle within the preset time includes: If the urea filling door switch signal shows that the urea filling door is opened within the preset time, it is determined that urea has been added to the vehicle within the preset time.

5. The urea quality detection method according to any one of claims 1 to 4, characterized in that: After determining whether the urea quality signal detected by the urea quality sensor in the vehicle is valid according to the ambient temperature, the method further includes: If the urea quality signal is valid, acquiring the urea quality signal and nitrogen oxygen detection data of a nitrogen oxygen sensor in the vehicle; The urea quality is detected according to the urea quality signal and the nitrogen oxide detection data.

6. The urea quality detection method according to claim 5, characterized in that: The detecting of urea quality according to the urea quality signal and the nitrogen oxide detection data comprises: If the urea quality signal indicates that the urea quality is qualified, determining that the urea quality is qualified; If the urea quality signal shows that the urea quality is unqualified, it is determined whether the nitrogen oxide emissions in the exhaust gas exceed the standard based on the nitrogen oxide detection data; if the nitrogen oxide emissions do not exceed the standard, it is determined that the urea quality is qualified; if the nitrogen oxide emissions exceed the standard, it is determined that the urea quality is unqualified.

7. The urea quality detection method according to claim 6, characterized in that: After judging whether the nitrogen oxide emission in the tail gas exceeds the standard according to the nitrogen oxide detection data, the method further includes: If the nitrogen oxide emission does not exceed the standard, it is determined that the urea quality sensor is faulty, and the vehicle is controlled to display a second alarm signal.

8. The urea quality detection method according to any one of claims 1 to 4, characterized in that: The determining, based on the ambient temperature, whether a urea quality signal detected by a urea quality sensor in the vehicle is valid includes: If the ambient temperature is greater than or equal to a preset temperature threshold, it is determined that the urea quality signal is valid; If the ambient temperature is less than the temperature threshold, it is determined that the urea quality signal is invalid.

9. A urea quality detection device, characterized in that: include: The acquisition module is used to obtain the current ambient temperature; A judging module, used for judging whether a urea quality signal detected by a urea quality sensor in the vehicle is valid according to the ambient temperature; The processing module is used for acquiring nitrogen oxide detection data of a nitrogen oxide sensor in the vehicle and urea filling information within a preset time if the urea quality signal is invalid; and detecting urea quality according to the nitrogen oxide detection data and the urea filling information.

10. A vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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