Vehicle diagnostic method, device, equipment, storage medium and program product

Abstract

The present application discloses a vehicle diagnosis method, device, equipment, storage medium and program product. The vehicle includes a fuel tank, a desorption device and an engine, the desorption device includes a carbon canister and a high-pressure desorption pipeline, wherein the high-pressure desorption pipeline includes a venturi tube; the method includes: when the engine is in a supercharged condition and the ventilation valve of the carbon canister is in a closed state, obtaining a target pressure change value, wherein the target pressure change value includes at least one of the following: a first pressure change value of the fuel tank within a first time measured by a pressure sensor set on the fuel tank; a second pressure change value of the fuel tank within a first time calculated by the fuel vapor desorbed by the venturi tube; according to the target pressure change value, determining the diagnosis result of the high-pressure desorption pipeline. The present application does not need to set a pressure sensor in the high-pressure desorption pipeline to diagnose whether the high-pressure desorption pipeline has a fault, thereby reducing the diagnostic cost of the high-pressure desorption pipeline.

Description

Technical Field

[0001] The present application belongs to the field of vehicle technology, and in particular, relates to a vehicle diagnosis method, device, equipment, storage medium and program product. Background Art

[0002] The fuel in the vehicle's fuel tank will evaporate into fuel vapor. The desorption device is used to introduce the fuel vapor into the engine cylinder for combustion to prevent the fuel vapor from evaporating into the atmosphere, causing fuel waste and environmental pollution. In order to meet the requirements of the "National VI" emission regulations, it is necessary to diagnose the desorption pipeline of the desorption device.

[0003] At present, for the high-pressure desorption pipeline in the desorption device, a pressure sensor is added to the high-pressure desorption pipeline to diagnose whether the high-pressure desorption pipeline has a fault, which leads to high diagnostic costs. Summary of the invention

[0004] The embodiments of the present application provide a vehicle diagnosis method, apparatus, device, storage medium and program product that can perform vehicle diagnosis.

[0005] In a first aspect, an embodiment of the present application provides a vehicle diagnostic method, wherein the vehicle comprises a fuel tank, a desorption device and an engine, wherein the desorption device comprises a carbon canister and a high-pressure desorption pipeline, wherein the high-pressure desorption pipeline comprises a venturi tube; the method comprises:

[0006] When the engine is in a supercharged condition and the ventilation valve of the carbon canister is in a closed state, a target pressure change value is obtained, wherein the target pressure change value includes at least one of the following: a first pressure change value of the fuel tank per unit time measured by a pressure sensor disposed on the fuel tank; a second pressure change value of the fuel tank per unit time calculated from the fuel vapor desorbed by the venturi tube;

[0007] A diagnosis result of the high-pressure desorption pipeline is determined according to the target pressure change value.

[0008] In a second aspect, an embodiment of the present application provides a vehicle diagnostic device, wherein the vehicle includes a fuel tank, a desorption device and an engine, the desorption device includes a carbon canister and a high-pressure desorption pipeline, and a pressure sensor is provided on the fuel tank; the device includes:

[0009] A first acquisition module is used to acquire a target pressure change value when the engine is in a supercharging condition and the ventilation valve of the carbon canister is in a closed state, wherein the target pressure change value includes at least one of the following: a first pressure change value of the fuel tank per unit time measured by a pressure sensor disposed on the fuel tank; a second pressure change value of the fuel tank per unit time calculated from the fuel vapor desorbed by the venturi tube;

[0010] The first determination module is used to determine the diagnosis result of the high-pressure desorption pipeline according to the target pressure change value.

[0011] In a third aspect, an embodiment of the present application provides a vehicle diagnostic device, comprising: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the vehicle diagnostic method as described in the first aspect is implemented.

[0012] In a fourth aspect, an embodiment of the present application provides a computer storage medium, wherein the computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the vehicle diagnostic method as described in the first aspect is implemented.

[0013] In a fifth aspect, an embodiment of the present application provides a computer program product. When instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the vehicle diagnostic method as described in the first aspect.

[0014] In the embodiment of the present application, when the engine is in a supercharged condition and the ventilation valve of the carbon canister is in a closed state, the pressure change of the fuel tank within the first time measured by the pressure sensor set on the fuel tank and / or the pressure change value of the fuel tank within the first time calculated by the fuel vapor desorbed by the venturi tube of the high-pressure desorption pipeline can be used to diagnose whether the high-pressure desorption pipeline has a fault. In this way, there is no need to set a pressure sensor on the high-pressure desorption pipeline to diagnose whether the high-pressure desorption pipeline has a fault, thereby reducing the diagnostic cost of the high-pressure desorption pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0017] Figure 2 It is one of the flow charts of the vehicle diagnostic method provided in the embodiment of the present application;

[0018] Figure 3 It is a schematic diagram of the structure of the venturi tube provided in the embodiment of the present application;

[0019] Figure 4 This is the second flow chart of the vehicle diagnostic method provided in the embodiment of the present application;

[0020] Figure 5is a structural diagram of a vehicle diagnostic device provided in an embodiment of the present application;

[0021] Figure 6 It is a structural diagram of the vehicle diagnostic equipment provided in the embodiment of the present application. DETAILED DESCRIPTION

[0022] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0023] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0024] For ease of understanding, some contents involved in the embodiments of the present application are described below:

[0025] For supercharged engines, Figure 1 As shown, there are two fuel vapor desorption pipelines behind the carbon canister valve, namely the high-pressure desorption pipeline and the low-pressure desorption pipeline.

[0026] The "National VI" emission regulations require that these two desorption pipes must be diagnosed as faulty if they are blocked or fall off.

[0027] The traditional diagnostic method is to use a closed system for the low-pressure desorption pipeline, draw a vacuum through engine operation, and detect changes in the pressure sensor installed on the fuel tank to determine whether there is a fault in the low-pressure desorption pipeline.

[0028] The high-pressure desorption pipeline directly determines whether a fault occurs in the high-pressure desorption pipeline through a pressure sensor behind the one-way valve under boost conditions. This diagnostic method requires adding a pressure sensor behind the one-way valve of the high-pressure desorption pipeline, resulting in a high diagnostic cost.

[0029] Based on this, an embodiment of the present application provides a new vehicle diagnostic method, which can diagnose whether a high-pressure desorption pipeline has a fault without adding a pressure sensor to the high-pressure desorption pipeline, thereby reducing the diagnostic cost of the high-pressure desorption pipeline.

[0030] The vehicle diagnostic method provided in the embodiment of the present application is described in detail below through some embodiments and their application scenarios in combination with the accompanying drawings.

[0031] See also Figure 2 , Figure 2 This is one of the flow charts of the vehicle diagnostic method provided in the embodiment of the present application.

[0032] like Figure 2 As shown, the vehicle diagnosis method may include the following steps:

[0033] Step 201, when the engine is in a boost condition and the ventilation valve of the carbon canister is in a closed state, obtain a target pressure change value, wherein the target pressure change value includes at least one of the following: a first pressure change value of the fuel tank within a first time measured by a pressure sensor provided on the fuel tank; a second pressure change value of the fuel tank within the first time calculated from the fuel vapor desorbed from the venturi tube.

[0034] The diagnosis of the high pressure desorption pipeline is performed under certain conditions (hereinafter referred to as the diagnosis conditions of the high pressure desorption pipeline). In step 201, the diagnosis conditions of the high pressure desorption pipeline may include: the engine is in a supercharged state, and the ventilation valve of the carbon canister is in a closed state.

[0035] When the engine is in a supercharged condition, the engine is in a high-load working state, and the fuel vapor is introduced into the engine cylinder through the high-pressure desorption pipeline for combustion. When the ventilation valve of the carbon canister is in a closed state, the fuel tank, the high-pressure desorption pipeline and the engine form a closed system. In this way, by diagnosing the high-pressure desorption pipeline in a working state through a closed system, the interference of air on the diagnosis of the high-pressure desorption pipeline can be reduced, thereby improving the reliability of the diagnosis of the high-pressure desorption pipeline.

[0036] Failure of the high-pressure desorption pipeline, such as blockage, shedding or leakage, will affect the pressure change of the fuel tank. Therefore, in the application embodiment, it is possible to diagnose whether the high-pressure desorption pipeline has a fault by the pressure change of the fuel tank in the closed system under the engine supercharging condition.

[0037] In specific implementation, the pressure change value of the fuel tank within the first time can be obtained to diagnose whether the high-pressure desorption pipeline has a fault. The starting time of the first time is the time when the diagnostic condition of the high-pressure desorption pipeline is satisfied, or it is located after the time when the diagnostic condition of the high-pressure desorption pipeline is satisfied. That is, step 201 obtains the pressure change value of the fuel tank after the diagnostic condition of the high-pressure desorption pipeline is satisfied. The first time may include one or more unit times.

[0038] In the embodiment of the present application, the pressure change value of the fuel tank within the first time can be obtained by the following method:

[0039] Method 1: measured by a pressure sensor disposed on the fuel tank, namely, a fuel tank pressure sensor. For the convenience of description, the pressure change value of the fuel tank detected by the fuel tank pressure sensor within the first time is recorded as the first pressure change value.

[0040] Method 2: The pressure change value of the fuel tank in the first time calculated by the fuel vapor desorbed by the Venturi tube is recorded as the second pressure change value for the convenience of description.

[0041] It is understandable that when a failure occurs in the high-pressure desorption pipeline, due to the abnormal flow of fuel vapor, on the one hand, the pressure change value of the fuel tank obtained at this time will be different from the pressure change value of the fuel tank obtained when the high-pressure desorption pipeline has not failed; on the other hand, the pressure change value of the fuel tank calculated by the fuel vapor desorbed by the venturi tube will be different from the pressure value of the fuel tank measured by the fuel tank pressure sensor.

[0042] Based on this, in the embodiment of the present application, the high-pressure desorption pipeline can be diagnosed through the first pressure change value and / or the second pressure change value.

[0043] Step 202: Determine a diagnosis result of the high-pressure desorption pipeline according to the target pressure change value.

[0044] In some embodiments, considering that the pressure change value of the fuel tank obtained when the high-pressure desorption pipeline fails may be different from the pressure change value of the fuel tank obtained when the high-pressure desorption pipeline does not fail, the first pressure change value or the second pressure change value can be used to diagnose the high-pressure desorption pipeline.

[0045] In these embodiments, the vehicle can obtain in advance a reference value of the pressure change of the fuel tank per unit time when the high-pressure desorption pipeline is not faulty, the engine is in a supercharged condition, and the ventilation valve of the carbon canister is in a closed state, hereinafter referred to as a first pressure change reference value. The first pressure change reference value can be pre-stored in the vehicle, or detected by a fuel tank pressure sensor when the high-pressure desorption pipeline is not faulty.

[0046] Afterwards, the first pressure change value (or the second pressure change value) can be compared with the first reference value to obtain a diagnostic result of the high-pressure desorption pipeline, wherein the first reference value is the product of the first pressure change reference value and the number of unit times included in the first time.

[0047] Specifically, when the difference between the first pressure change value (or the second pressure change value) and the first reference value is less than or equal to the second threshold value, it indicates that the flow of fuel vapor is normal, and it can be determined that the diagnosis result of the high-pressure desorption pipeline is that there is no fault in the high-pressure desorption pipeline.

[0048] When the difference between the first pressure change value (or the second pressure change value) and the first reference value is greater than the second threshold, it indicates that the flow of fuel vapor is abnormal, and the diagnosis result of the high-pressure desorption pipeline can be determined as a failure of the high-pressure desorption pipeline.

[0049] In other embodiments, considering that when a high-pressure desorption pipeline fails, there may be a difference between the pressure change value of the fuel tank calculated by desorbing the fuel vapor through the venturi tube and the pressure value of the fuel tank measured by the fuel tank pressure sensor, the first pressure change value and the second pressure change value may be used to diagnose the high-pressure desorption pipeline.

[0050] In these embodiments, determining the diagnosis result of the high-pressure desorption pipeline according to the target pressure change value may include:

[0051] Compare the difference between the first pressure change value and the second pressure change value with a first threshold value to obtain a comparison result;

[0052] Determining a diagnosis result of the high-pressure desorption pipeline according to the comparison result;

[0053] Wherein, when the comparison result is that the difference is greater than the first threshold, the diagnosis result is that the high-pressure desorption pipeline has a fault; when the comparison result is that the difference is less than or equal to the first threshold, the diagnosis result is that the high-pressure desorption pipeline has not a fault.

[0054] The first threshold value and the second threshold value may be equal or different, and may be set according to actual needs, which is not limited in the embodiment of the present application.

[0055] After determining the diagnosis result of the high-pressure desorption pipeline, the diagnosis result of the high-pressure desorption pipeline may be output. Further, the diagnosis result may be output if the diagnosis result is that the high-pressure desorption pipeline is faulty, otherwise, the diagnosis result may not be output.

[0056] The vehicle diagnosis method of this embodiment, when the engine is in a supercharged condition and the ventilation valve of the carbon canister is in a closed state, can diagnose whether the high-pressure desorption pipeline has a fault by measuring the change in the fuel tank pressure within the first time by the pressure sensor set on the fuel tank, and / or by calculating the pressure change value of the fuel tank within the first time by the fuel vapor desorbed by the venturi tube of the high-pressure desorption pipeline. In this way, there is no need to set a pressure sensor on the high-pressure desorption pipeline to diagnose whether the high-pressure desorption pipeline has a fault, thereby reducing the diagnostic cost of the high-pressure desorption pipeline. .

[0057] The acquisition of the second pressure change value is described below.

[0058] Optionally, obtaining the target pressure change value includes:

[0059] Obtaining a first mass of fuel vapor desorbed from the venturi tube within the first time;

[0060] A second pressure change value of the fuel tank within the first time is determined according to the first mass.

[0061] As can be seen from the above content, the first time includes at least one unit time. In specific implementation, the mass of the fuel vapor desorbed by the venturi tube in each unit time in the first time can be obtained, that is, the mass flow rate of the fuel vapor desorbed by the venturi tube in each unit time. Then, the sum of the masses of the fuel vapor desorbed by the venturi tube in each unit time is calculated to obtain the first mass.

[0062] In some optional implementations, the mass flow rate of fuel vapor desorbed from the venturi tube per unit time may be measured by a device.

[0063] In another optional implementation, the obtaining the first mass of the fuel vapor desorbed from the fuel tank by the venturi tube within the first time may include:

[0064] Using the flow field model of the venturi tube, calculating a first mass of the fuel vapor desorbed from the fuel tank by the venturi tube within the first time;

[0065] Wherein, the flow field model is established based on fluid mechanics formulas.

[0066] In this optional implementation, the mass flow rate of the fuel vapor desorbed by the venturi tube per unit time can be calculated by the flow field model of the venturi tube, and the flow field model of the venturi tube is established based on the fluid mechanics formula. In this way, there is no need to set up a measurement device for the mass flow rate of the fuel vapor desorbed by the venturi tube, thereby reducing the diagnostic cost of the high-pressure desorption pipeline.

[0067] Optionally, before calculating the first mass of the fuel vapor desorbed from the fuel tank by the Venturi tube within the first time using the flow field model of the Venturi tube, the method may further include:

[0068] Determine the gas sonic mass flow rate of the Venturi tube under standard conditions according to the throat cross-sectional area of ​​the Venturi tube;

[0069] Obtaining a density correction coefficient of the venturi tube under standard conditions, wherein the density correction coefficient is determined based on the pressure and temperature at the inlet end of the venturi tube under standard conditions;

[0070] Obtaining speed-to-sound ratio and pressure ratio characteristics of the venturi tube, wherein the speed-to-sound ratio and pressure ratio characteristics are determined based on the pressure at the outlet end of the venturi tube and the pressure at the inlet end of the venturi tube;

[0071] The flow field model is established according to the gas sonic mass flow rate, the density correction coefficient, and the velocity-sonic ratio and pressure ratio characteristics.

[0072] The structure of the Venturi tube can be found in Figure 3 ,exist Figure 3 In the figure, A represents the minimum cross-sectional area of ​​the venturi tube, that is, the throat cross-sectional area of ​​the venturi tube. The gas flows from left to right, so the left side of A is the inlet end of the venturi tube, and the right side of A is the outlet end of the venturi tube. p1 is the pressure at the inlet end, T1 is the temperature at the inlet end, and p2 is the pressure at the outlet end.

[0073] First, based on the fluid mechanics formula, the gas sonic mass flow rate of the Venturi tube can be calculated using formula (1), that is, the gas flow mass at the sonic speed

[0074]

[0075] Where ρ is the gas density, is the volume flow rate of gas at the speed of sound; R is the thermodynamic constant, ε is the isentropic coefficient, and ε of gas is 1.4.

[0076] Then, we can use formula (2) to obtain Calculate the mass flow rate of gas flowing through the Venturi tube per unit time

[0077]

[0078] Among them, G is the speed-sonic ratio and pressure ratio characteristics; is the gas sonic mass flow rate of the Venturi tube under standard conditions, which can be calculated by formula (3); DC(p, T) is the density correction coefficient of the Venturi tube, which can be calculated by formula (4).

[0079]

[0080]

[0081] Formula (2) is the flow field model of the Venturi tube. Therefore, we can first obtain DC(p,T) and Afterwards, the flow field model is created using these three parameters.

[0082] After the flow field model of the venturi tube is established, the flow field model can be used to calculate the mass of fuel vapor desorbed by the venturi tube in each unit time in the first time, and then the first mass of fuel vapor desorbed by the venturi tube in the first time can be obtained.

[0083] The carbon canister cleaning process lasts for a long time, and the heat exchange with the outside world is sufficient. Based on the thermodynamic formula, the isothermal expansion model at time t is as shown in formula (5), and the isothermal expansion model at time t+Δt is as shown in formula (6):

[0084] P tank (t)·V0=m0RT0 (5)

[0085]

[0086] Combining formula (5) and formula (6), we can get the calculation formula (7) for the pressure change value of the fuel tank between the start time (Init) and the end time (Final):

[0087]

[0088] Where T0 is the system temperature, which remains unchanged during the isothermal expansion process; m0 is the total amount of gas in the fuel tank when the vent valve of the carbon canister is closed; V0 is the volume of gas in the fuel tank; P tank (t) is the absolute pressure of the fuel tank at time t.

[0089] After obtaining the first mass, the first mass can be substituted into the formula (7) A second pressure change value of the fuel tank within the first time is obtained.

[0090] Through the above method, the mass of fuel vapor desorbed by the Venturi tube per unit time can be calculated through the flow field model of the Venturi tube, and then the mass of fuel vapor desorbed by the Venturi tube per unit time can be used to reversely estimate the pressure change value of the fuel tank per unit time. In this way, the estimated reliability of the pressure change value of the fuel tank per unit time can be improved, thereby improving the reliability of diagnosis.

[0091] In some embodiments, the desorption device further comprises a low-pressure desorption pipeline;

[0092] The method further comprises:

[0093] When the engine is in a low-pressure working condition and the ventilation valve of the carbon canister is in a closed state, a third pressure change value of the fuel tank within a second time is measured by the pressure sensor;

[0094] A diagnosis result of the low-pressure desorption pipeline is determined according to the third pressure change value.

[0095] In this embodiment, the fuel tank pressure sensor can be used to diagnose the low-pressure desorption pipeline.

[0096] In specific implementation, when the engine is in a low-pressure working condition, that is, a low-load working state, the low-pressure desorption pipeline adopts a closed system, and the vacuum is drawn by running the engine to monitor the pressure changes detected by the fuel tank pressure sensor to determine whether there is a fault in the low-pressure desorption pipeline.

[0097] In these embodiments, the vehicle can obtain in advance a reference value of the pressure change of the fuel tank per unit time when the low-pressure desorption pipeline is not faulty, the engine is in a supercharged condition, and the ventilation valve of the carbon canister is in a closed state, hereinafter referred to as a second pressure change reference value. The second pressure change reference value can be pre-stored in the vehicle, or detected by a fuel tank pressure sensor when the low-pressure desorption pipeline is not faulty.

[0098] Afterwards, the third pressure change value may be compared with the second reference value to obtain a diagnosis result of the low-pressure desorption pipeline, wherein the second reference value is the product of the second pressure change reference value and the number of unit times included in the second time.

[0099] Specifically, when the difference between the third pressure change value and the second reference value is less than or equal to the third threshold, it indicates that the flow of fuel vapor is normal, and it can be determined that the diagnosis result of the low-pressure desorption pipeline is that the low-pressure desorption pipeline is not faulty.

[0100] When the difference between the third pressure change value and the second reference value is greater than the third threshold value, it indicates that the flow of fuel vapor is abnormal, and it can be determined that the diagnosis result of the low-pressure desorption pipeline is that the low-pressure desorption pipeline is faulty.

[0101] It can be seen that in the embodiment of the present application, the fuel tank pressure sensor can be used to diagnose both the high-pressure desorption pipeline and the low-pressure desorption pipeline, thereby expanding the function of the fuel tank pressure sensor.

[0102] It should be noted that the various optional implementations introduced in the embodiments of the present application can be implemented in combination with each other or separately if they do not conflict with each other, and the embodiments of the present application are not limited to this.

[0103] For ease of understanding, the following examples are provided:

[0104] In this example, the diagnostic scheme for the high-pressure desorption line is as follows:

[0105] Step 1: The flow field model inside the Venturi pipe can be calculated based on the fluid mechanics formula.

[0106] Step 2: Calculate the mass of the tank steam desorbed through the Venturi tube per unit time based on the flow field model of the Venturi tube.

[0107] Step 3: Based on the desorbed tank vapor, the change in pressure inside the tank per unit time can be calculated.

[0108] Step 4: Compare the measured change in tank pressure per unit time with the calculated change in pressure. If the difference between the two is greater than the calibration threshold, it is considered that the high-pressure desorption pipeline is faulty. If it is less than or equal to the threshold, it is considered that the high-pressure desorption pipeline is not faulty.

[0109] like Figure 4 As shown, the diagnostic method of the high-pressure desorption pipeline may include the following steps:

[0110] Step 401, entering into diagnosis when the diagnosis conditions of the high-pressure desorption pipeline are met.

[0111] Step 402, calculating the mass of fuel vapor desorbed from the venturi tube;

[0112] Step 403, estimating the pressure change of the fuel tank according to the mass of the fuel vapor desorbed from the venturi tube to obtain an estimated value;

[0113] Step 404, measuring the pressure change of the fuel tank by the fuel tank pressure sensor to obtain a measured value;

[0114] Step 405, determining whether the difference between the estimated value and the measured value is greater than a threshold.

[0115] If yes, execute step 406; if no, execute step 407.

[0116] Step 406, diagnose that the high-pressure desorption pipeline has a fault and report the fault.

[0117] Step 407, diagnose that the high-pressure desorption pipeline has no fault.

[0118] Through the vehicle diagnostic method of the embodiment of the present application, the pressure sensor on the high-desorption pipeline of the supercharged engine can be eliminated. In this way, on the one hand, the manufacturing cost of the entire vehicle can be saved; on the other hand, the complexity of the diagnostic system is reduced. The elimination of the pressure sensor itself eliminates the self-diagnosis of the sensor, and the design of the diagnostic system is simpler.

[0119] The application scope of the low-pressure desorption pipeline diagnostic function and the fuel tank pressure sensor has been expanded. The original purpose of the fuel tank pressure sensor is to diagnose the detachment or blockage of the low-pressure desorption pipeline, and the embodiment of the present application can also use the fuel tank pressure sensor to monitor the diagnosis of the high-pressure desorption pipeline, which is equivalent to expanding the application scope of the original function and improving the practicality of the diagnostic system.

[0120] Based on the vehicle diagnostic method provided in the above embodiment, the present application also provides a specific implementation of a vehicle diagnostic device. Please refer to the following embodiment.

[0121] See also Figure 5 The vehicle diagnostic device provided in the embodiment of the present application may include:

[0122] A first acquisition module is used to acquire a target pressure change value when the engine is in a supercharging condition and the ventilation valve of the carbon canister is in a closed state, wherein the target pressure change value includes at least one of the following: a first pressure change value of the fuel tank per unit time measured by a pressure sensor disposed on the fuel tank; a second pressure change value of the fuel tank per unit time calculated from the fuel vapor desorbed by the venturi tube;

[0123] The first determination module is used to determine the diagnosis result of the high-pressure desorption pipeline according to the target pressure change value.

[0124] In some embodiments, the first acquisition module includes:

[0125] An acquisition unit, configured to acquire a first mass of fuel vapor desorbed from the venturi tube within the first time;

[0126] A first determining unit is configured to determine a second pressure change value of the fuel tank within the first time according to the first mass.

[0127] In some embodiments, the acquisition unit is used to:

[0128] Using the flow field model of the venturi tube, calculating a first mass of the fuel vapor desorbed from the fuel tank by the venturi tube within the first time;

[0129] Wherein, the flow field model is established based on fluid mechanics formulas.

[0130] In some embodiments, the apparatus further comprises:

[0131] A second determination module is used to determine the gas sonic mass flow rate of the Venturi tube under standard conditions according to the throat cross-sectional area of ​​the Venturi tube;

[0132] A second acquisition module is used to acquire a density correction coefficient of the venturi tube under standard conditions, wherein the density correction coefficient is determined based on the pressure and temperature at the inlet end of the venturi tube under standard conditions;

[0133] A third acquisition module is used to obtain the speed-sound speed ratio and pressure ratio characteristics of the venturi tube, wherein the speed-sound speed ratio and pressure ratio characteristics are determined based on the pressure at the outlet end of the venturi tube and the pressure at the inlet end of the venturi tube;

[0134] The module is used to establish the flow field model according to the gas sonic mass flow rate, the density correction coefficient and the velocity sonic ratio and pressure ratio characteristics.

[0135] In some embodiments, the first determining module includes:

[0136] a comparing unit, configured to compare a difference between the first pressure change value and the second pressure change value with a first threshold value to obtain a comparison result;

[0137] a second determining unit, configured to determine a diagnosis result of the high-pressure desorption pipeline according to the comparison result;

[0138] Wherein, when the comparison result is that the difference is greater than the first threshold, the diagnosis result is that the high-pressure desorption pipeline has a fault; when the comparison result is that the difference is less than or equal to the first threshold, the diagnosis result is that the high-pressure desorption pipeline has not a fault.

[0139] In some embodiments, the desorption device further comprises a low-pressure desorption pipeline;

[0140] The device also includes:

[0141] A measuring module, configured to measure, by means of the pressure sensor, a third pressure change value of the fuel tank within a second time when the engine is in a low-pressure working condition and the ventilation valve of the carbon canister is in a closed state;

[0142] The fourth determination module is used to determine the diagnosis result of the low-pressure desorption pipeline according to the third pressure change value.

[0143] The vehicle diagnostic device provided in the embodiment of the present application can implement each process implemented by the vehicle diagnostic device in the method embodiment, and will not be described again here to avoid repetition.

[0144] Figure 6 A hardware structure diagram of the vehicle diagnosis provided in an embodiment of the present application is shown.

[0145] The vehicle diagnostic device may include a processor 601 and a memory 602 storing computer program instructions.

[0146] Specifically, the processor 601 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0147] The memory 602 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 602 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 602 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 602 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 602 is a non-volatile solid-state memory.

[0148] The memory may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Therefore, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of the present disclosure.

[0149] The processor 601 implements any one of the vehicle diagnosis methods in the above embodiments by reading and executing computer program instructions stored in the memory 602 .

[0150] In one example, the vehicle diagnostic device may further include a communication interface 606 and a bus 610. Figure 6 As shown, the processor 601, the memory 602, and the communication interface 606 are connected via a bus 610 and communicate with each other.

[0151] The communication interface 606 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0152] Bus 610 includes hardware, software or both, and the parts of vehicle diagnostic equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 610 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the present application considers any suitable bus or interconnection.

[0153] In addition, in combination with the vehicle diagnostic method in the above embodiment, the embodiment of the present application can provide a computer storage medium to implement. The computer storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any one of the vehicle diagnostic methods in the above embodiment is implemented.

[0154] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0155] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0156] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0157] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0158] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A vehicle diagnostic method, characterized in that: The vehicle comprises a fuel tank, a desorption device and an engine, the desorption device comprises a carbon canister and a high-pressure desorption pipeline, wherein the high-pressure desorption pipeline comprises a venturi tube; the method comprises: When the engine is in a supercharging condition and the ventilation valve of the carbon canister is in a closed state, a target pressure change value is obtained, wherein the target pressure change value includes: a first pressure change value of the fuel tank within a first time measured by a pressure sensor disposed on the fuel tank; a second pressure change value of the fuel tank within the first time calculated by the fuel vapor desorbed by the venturi tube; Determining a diagnosis result of the high-pressure desorption pipeline according to the target pressure change value; Wherein, obtaining the target pressure change value includes: Determine the gas sonic mass flow rate of the Venturi tube under standard conditions according to the throat cross-sectional area of ​​the Venturi tube; Obtaining a density correction coefficient of the venturi tube under standard conditions, wherein the density correction coefficient is determined based on the pressure and temperature at the inlet end of the venturi tube under standard conditions; Acquiring the velocity-sound-velocity ratio and pressure-ratio characteristics of the venturi tube, wherein the velocity-sound-velocity ratio and pressure-ratio characteristics are determined based on the pressure at the outlet end of the venturi tube and the pressure at the inlet end of the venturi tube; A flow field model is established according to the gas sonic mass flow rate, the density correction coefficient, and the velocity-sonic ratio and pressure ratio characteristics, wherein the flow field model is established based on a fluid mechanics formula; Using the flow field model, calculating a first mass of the fuel vapor desorbed from the fuel tank by the venturi tube within the first time; A second pressure change value of the fuel tank within the first time is determined according to the first mass.

2. The method according to claim 1, characterized in that Determining the diagnosis result of the high-pressure desorption pipeline according to the target pressure change value includes: Compare the difference between the first pressure change value and the second pressure change value with a first threshold value to obtain a comparison result; Determining a diagnosis result of the high-pressure desorption pipeline according to the comparison result; Wherein, when the comparison result is that the difference is greater than the first threshold, the diagnosis result is that the high-pressure desorption pipeline has a fault; when the comparison result is that the difference is less than or equal to the first threshold, the diagnosis result is that the high-pressure desorption pipeline has not a fault.

3. The method according to claim 1, characterized in that The desorption device also includes a low-pressure desorption pipeline; The method further comprises: When the engine is in a low-pressure working condition and the ventilation valve of the carbon canister is in a closed state, a third pressure change value of the fuel tank within a second time is measured by the pressure sensor; A diagnosis result of the low-pressure desorption pipeline is determined according to the third pressure change value.

4. A vehicle diagnostic device, characterized in that: The vehicle comprises a fuel tank, a desorption device and an engine, the desorption device comprises a carbon canister and a high-pressure desorption pipeline, wherein the high-pressure desorption pipeline comprises a venturi tube; the device comprises: A first acquisition module is used to acquire a target pressure change value when the engine is in a supercharging condition and the ventilation valve of the carbon canister is in a closed state, wherein the target pressure change value includes: a first pressure change value of the fuel tank per unit time measured by a pressure sensor arranged on the fuel tank; a second pressure change value of the fuel tank per unit time calculated by the fuel vapor desorbed by the venturi tube; A first determination module, configured to determine a diagnosis result of the high-pressure desorption pipeline according to the target pressure change value; The device also includes: A second determination module is used to determine the gas sonic mass flow rate of the Venturi tube under standard conditions according to the throat cross-sectional area of ​​the Venturi tube; A second acquisition module is used to acquire a density correction coefficient of the venturi tube under standard conditions, wherein the density correction coefficient is determined based on the pressure and temperature at the inlet end of the venturi tube under standard conditions; A third acquisition module is used to obtain the speed-sound speed ratio and pressure ratio characteristics of the venturi tube, wherein the speed-sound speed ratio and pressure ratio characteristics are determined based on the pressure at the outlet end of the venturi tube and the pressure at the inlet end of the venturi tube; An establishment module is used to establish a flow field model according to the gas sonic mass flow rate, the density correction coefficient and the velocity sonic ratio and pressure ratio characteristics, wherein the flow field model is established based on a fluid mechanics formula; Wherein, the first acquisition module includes: An acquisition unit, configured to calculate, by using the flow field model, a first mass of the fuel vapor desorbed from the fuel tank by the venturi tube within the unit time; A first determining unit is configured to determine a second pressure change value of the fuel tank within the unit time according to the first mass.

5. A vehicle diagnostic device, characterized in that: The device comprises: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the vehicle diagnosis method according to any one of claims 1 to 3 is implemented.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the vehicle diagnosis method according to any one of claims 1 to 3 is implemented.

7. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes the vehicle diagnosis method as claimed in any one of claims 1 to 3.

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