Diagnostic method and device for evaporation leakage, vehicle and storage medium

Abstract

The invention provides an evaporation leakage diagnosis method and device, a vehicle and a storage medium. The method comprises the following steps: firstly, initiating a first turn of evaporation leakage detection process for a target vehicle, and if the execution of the first turn of evaporation leakage detection process is in a cold engine starting state of the target vehicle, selecting to re-initiate a second turn of evaporation leakage detection process without adopting a corresponding detection result; and whether the fuel evaporation system has an evaporation leakage fault or not is diagnosed based on the new detection result. And for the evaporation leakage detection process of the second round, the evaporation leakage detection process of the first round initiated before can be regarded as preheating preparation of the engine, so that the situation that the diagnosis result of evaporation leakage is inaccurate due to the fact that the pressure of the oil tank is intensively changed due to the fact that the temperature of the engine is greatly increased is avoided. Especially in a vehicle maintenance scene, an inaccurate diagnosis result can be prevented from misleading after-sales personnel to troubleshoot.

Description

Technical Field

[0001] The present application relates to the field of vehicle fault diagnosis, and in particular to a method, device, vehicle and storage medium for diagnosing evaporative leakage. Background Art

[0002] Leaks in a vehicle's fuel evaporation system are also known as evaporative leaks. When diagnosing the fuel evaporation system, if the leakage reaches a level equivalent to a 1mm pore diameter, it is considered an evaporative leak. The specific detection method is to first evacuate the fuel tank to a negative pressure state and then quantify the leakage based on the change in tank pressure.

[0003] However, in actual operation, when a vehicle is started from a cold engine, its fuel tank pressure will change significantly due to the engine heating up. If the diagnosis is performed after the cold engine is started, it may cause a false alarm of evaporative leakage. Summary of the Invention

[0004] The purpose of this application is to provide a diagnostic method, device, vehicle and storage medium for evaporative leakage, which can solve the problem of inaccurate evaporative leakage diagnosis in the prior art caused by the influence of vehicle cold engine start-up.

[0005] In order to achieve the above objectives, the embodiments of the present application are implemented as follows: In a first aspect, a method for diagnosing evaporative leakage is provided, comprising: Initiate the first round of evaporative leak detection process for the target vehicle's fuel evaporative system; If the target vehicle is in a cold engine start state during the execution of the first round of the evaporative leak detection process, ignoring the first round of detection results and initiating a second round of the evaporative leak detection process for the fuel evaporation system; as well as, Based on the second round of detection results, it is diagnosed whether the fuel evaporation system has evaporation leakage.

[0006] Optionally, the method also includes: if the first round of the evaporative leak detection process is initiated for the first time after a cold engine start, determining that the first round of the evaporative leak detection process is in a cold engine start state of the target vehicle during execution; otherwise, determining that the first round of the evaporative leak detection process is in a non-cold engine start state of the target vehicle during execution.

[0007] Optionally, the method also includes: obtaining the engine temperature and the ambient temperature of the target vehicle during the execution of the evaporative leakage detection process in the first round; if the difference between the engine temperature and the ambient temperature is less than or equal to a first preset temperature threshold, determining that the target vehicle is in a cold engine start state during the execution of the evaporative leakage detection process in the first round, otherwise determining that the target vehicle is in a non-cold engine start state during the execution of the evaporative leakage detection process in the first round; wherein, when the ambient temperature is greater than a second preset temperature threshold, the first preset temperature threshold is negatively correlated with a preset adjustment coefficient, and the value of the preset adjustment coefficient is determined based on the absolute value difference between the engine temperature and the reference ambient temperature.

[0008] Optionally, when the ambient temperature is greater than a second preset temperature threshold, the first preset temperature threshold is negatively correlated with a preset adjustment coefficient, and the value of the preset adjustment coefficient is the absolute value difference between the engine temperature of the target vehicle and the reference ambient temperature.

[0009] Optionally, after determining the vehicle startup state in which the evaporative leakage detection process of the first round is executed, the method further includes: if the vehicle startup state is not in a cold engine startup state during the execution of the evaporative leakage detection process of the first round, diagnosing whether evaporative leakage occurs in the fuel evaporation system based on the detection results of the first round.

[0010] Optionally, the evaporative leak detection process includes: adjusting the fuel tank pressure of the target vehicle to a negative pressure, and recording a pressure change gradient corresponding to the fuel tank pressure after being adjusted to the negative pressure; wherein the pressure change gradient serves as a detection result of the evaporative leak detection process.

[0011] Optionally, diagnosing whether evaporation leakage occurs in the fuel evaporation system based on the second round of detection results includes: if the detection results of the second round of the evaporation leakage detection process indicate that the pressure change gradient reaches a corresponding preset pressure change standard, determining that evaporation leakage occurs in the fuel evaporation system.

[0012] Optionally, the evaporative leak detection process is executed when the target vehicle meets preset vehicle conditions; the preset vehicle conditions include at least one of the following: the ambient temperature is within a corresponding reasonable range; no preset gross leakage fault occurs; the carbon canister load is within a corresponding reasonable range; the fuel level is within a corresponding reasonable range; the carbon canister flushing flow integral is greater than or equal to a corresponding preset threshold; the engine starting water temperature is within a corresponding reasonable range; the battery operating voltage is within a corresponding reasonable range; the fuel tank pressure is within a corresponding reasonable range; the ambient pressure is greater than or equal to the corresponding preset threshold; the manifold pressure is less than or equal to the corresponding preset threshold; the vehicle speed is less than or equal to the corresponding preset threshold.

[0013] In a second aspect, a diagnostic device for evaporative leakage is provided, comprising: A detection execution module, used to initiate a first round of evaporative leak detection process for the fuel evaporative system of the target vehicle; a detection decision module, configured to, if the first round of the evaporative leak detection process is in a cold engine start state, ignore the detection results of the first round and initiate a second round of the evaporative leak detection process for the fuel evaporative system; The diagnosis execution module is configured to diagnose whether evaporation leakage occurs in the fuel evaporation system based on the detection result of the second round.

[0014] In a third aspect, a vehicle is provided, comprising: a memory for storing executable program code; A processor is used to call and run the executable program code from the memory, so that the vehicle executes the method described in the first aspect.

[0015] According to a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed, the method described in the first aspect is implemented.

[0016] In an embodiment of the present application, a first round of evaporative leak detection is initiated for the target vehicle. If the target vehicle is in a cold engine start state during the first round of evaporative leak detection, the corresponding test results are not used, and a second round of evaporative leak detection is re-initiated to diagnose whether the fuel evaporation system has an evaporative leak fault based on the new test results. For the second round of evaporative leak detection, the previously initiated first round of evaporative leak detection can be regarded as an engine warm-up preparation, thereby preventing the fuel tank pressure from being aggravated by the engine's significant temperature increase, which could lead to inaccurate evaporative leak diagnosis results. This can be particularly effective in vehicle maintenance scenarios, preventing inaccurate diagnostic results from misleading after-sales personnel in troubleshooting the problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a first flow chart of the evaporative leak diagnosis method according to an embodiment of the present application.

[0019] Figure 2 This is a second flow chart of the evaporative leak diagnosis method according to an embodiment of the present application.

[0020] Figure 3 This is a third flow chart of the evaporative leak diagnosis method according to an embodiment of the present application.

[0021] Figure 4 This is a fourth flow chart of the evaporative leak diagnosis method according to an embodiment of the present application.

[0022] Figure 5 Schematic diagram of the structure of the evaporative leakage diagnostic device according to an embodiment of the present application.

[0023] Figure 6 This is a schematic structural diagram of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this specification.

[0025] Evaporative leaks refer to leaks in a vehicle's fuel evaporation system, which cause fuel vapor to escape and pollute the air. To meet China VI emission standards, vehicles must be able to detect and diagnose evaporative leaks. Specifically, if the evaporative system leaks reach the equivalent of a 1mm pore (approximately 0.04 inches), the vehicle's on-board diagnostics (OBD) system will trigger a fault alarm.

[0026] To detect evaporative leaks, the industry typically uses the negative pressure method, which involves pumping the vehicle's fuel tank into a negative pressure state and determining the amount of leakage based on the subsequent tank pressure changes.

[0027] The above detection process is usually completed when the vehicle is idling. If the detection is performed shortly after starting a cold engine, the rapid increase in engine temperature will aggravate the fluctuation of the fuel tank pressure, which may lead to a false alarm of evaporation leakage fault.

[0028] In actual vehicle maintenance scenarios, if after-sales personnel choose to wait until the engine is preheated before performing the inspection, they will inevitably fail to strictly comply with the standards due to arbitrariness, and there is still the possibility of being misled by inaccurate diagnostic results.

[0029] In light of this, the present application provides a diagnostic solution for evaporative leaks that does not rely on manual intervention. After completing a first round of evaporative leak detection during a cold engine start, the solution treats the first round of evaporative leak detection as a warm-up phase for the engine. The corresponding test results are not used, and a second round of evaporative leak detection is re-initiated to diagnose whether an evaporative leak fault has occurred in the fuel evaporation system based on the new test results. It should be understood that the present application ensures that the engine reaches a certain temperature in advance through the first round of preheating, thereby preventing the second round of evaporative leak detection from exacerbating changes in fuel tank pressure due to excessive engine temperature fluctuations, which could affect diagnostic accuracy.

[0030] The evaporation leakage diagnosis scheme of the present application is described in detail below with reference to the embodiments.

[0031] Specifically, an embodiment of the present application provides a method for diagnosing evaporative leakage. Figure 1 The figure is a flow chart of the diagnostic method, which includes the following steps: S101, initiating a first round of evaporation leak detection process for the fuel evaporation system of the target vehicle.

[0032] In this embodiment, the "first round" may refer to the first time after the target vehicle's engine is started, or may refer to a non-first time (e.g., the second, ..., fourth, etc.) after the target vehicle's engine is started. This definition of the "first round" of the evaporative leak detection process is used to distinguish it from the subsequent "second round" of the evaporative leak detection process.

[0033] The evaporative leak detection process for each round primarily involves adjusting the target vehicle's fuel tank pressure to a negative pressure and then recording the corresponding pressure gradient after the tank pressure is adjusted to a negative pressure. It should be noted that if the fuel evaporative leak system exhibits an evaporative leak, the tank pressure will rapidly increase within a short period of time after being adjusted to a negative pressure. This change, expressed over time, is referred to as the pressure gradient in this article. In other words, the pressure gradient reflects the rate of change of the fuel tank pressure over a given period of time. Clearly, when this rate of change exceeds a certain level, an evaporative leak is confirmed. Therefore, the recorded pressure gradient serves as the test result of the evaporative leak detection process.

[0034] In practical applications, in order to reduce the interference of external factors on the detection results, this embodiment can initiate each round of evaporative leak detection process when the target vehicle is in the following preset vehicle conditions: 1) The ambient temperature is within the corresponding reasonable range; Excessively high or low ambient temperatures can distort the pressure gradient of the fuel evaporation system, affecting the accuracy of detection results. For example, high temperatures accelerate fuel evaporation, while low temperatures reduce gas flow velocity, causing detection results to deviate from the actual situation. Therefore, before initiating the evaporative leak detection process, this embodiment ensures that the ambient temperature is within the corresponding reasonable range, that is, eliminates the interference of ambient temperature on evaporative leak detection.

[0035] 2) The preset gross leakage fault does not occur; Gross leaks are often caused by user negligence, such as leaving the fuel tank cap open or the canister vent valve open. Based on the foregoing, the general process for evaporative leak detection involves first pumping the vehicle's fuel tank to a negative pressure state, then determining the leakage amount based on the tank pressure gradient. However, if a gross leak occurs, the tank pressure cannot be pumped to a negative pressure state, further affecting the test results. Therefore, this embodiment ensures that no gross leaks of this type have occurred before initiating the evaporative leak detection process.

[0036] 3) The carbon canister load is within the corresponding reasonable range; The fuel tank can only be evacuated to negative pressure when the fuel evaporation system is relatively airtight. A closed canister vent valve is a prerequisite for maintaining a closed fuel evaporation system. Therefore, this embodiment verifies whether the canister vent valve is closed by monitoring the canister load before initiating evaporative leak detection. This ensures that the canister load is within a reasonable range.

[0037] 4) The fuel level is within the corresponding reasonable range; The fuel level is related to the pressure decay of the fuel evaporation system. Evaporative leak testing on the same vehicle at high and low fuel levels will produce different pressure gradients. Therefore, it's important to establish a reasonable fuel level range as a unified testing standard.

[0038] 5) The carbon canister flushing flow integral is greater than or equal to the corresponding preset threshold; Based on the foregoing, the closure of the canister vent valve is a prerequisite for maintaining a sealed fuel evaporation system. If the canister vent valve is not fully closed, vapor within the fuel evaporation system will be discharged into the atmosphere through the valve, significantly reducing the canister's desorption capacity. Therefore, this embodiment verifies the closure of the canister vent valve by monitoring the canister flushing flow integral (the cumulative value of the canister desorption flow over a specified period) before initiating evaporative leak detection. Specifically, the canister flushing flow integral must be greater than or equal to a preset threshold.

[0039] 6) The engine starting water temperature is within the corresponding reasonable range; Based on the above, the fuel evaporation system will cause pressure gradient distortion at either excessively high or low ambient temperatures. Engine starting water temperature affects engine temperature, which in turn affects ambient temperature. Therefore, this embodiment ensures that the engine starting water temperature is within a reasonable range before initiating evaporative leak detection, eliminating interference from the engine starting water temperature on evaporative leak detection.

[0040] 7) The battery operating voltage is within the corresponding reasonable range; During the evaporative leak detection process, if the battery operating voltage is abnormal, vehicle components used in the evaporative leak detection (such as pressure sensors and solenoid valves) may become unstable, potentially leading to misdiagnosis or missed diagnosis. To avoid this problem, this embodiment ensures that the battery operating voltage is within a reasonable range before initiating the evaporative leak detection process.

[0041] 8) The fuel tank pressure is within the corresponding reasonable range; Fuel tank pressure is an important indicator for determining a gross leak. As previously mentioned, a gross leak can prevent the fuel tank from being pumped to a negative pressure, leading to abnormal execution of the evaporative leak detection process. Therefore, this embodiment ensures that the fuel tank pressure is within a reasonable range before initiating evaporative leak detection, eliminating the interference of gross leaks on evaporative leak detection.

[0042] 9) The ambient pressure is greater than or equal to the corresponding preset threshold; Ambient pressure is also related to the pressure decay strength of the fuel evaporation system. When the ambient pressure is too low, it accelerates the discharge of fuel evaporation, resulting in an abnormally large pressure gradient. Conversely, when the ambient pressure is too high, it inhibits the discharge of fuel evaporation, resulting in an abnormally small pressure gradient. Both of these factors can affect the accuracy of detection results. Therefore, this embodiment ensures that the ambient pressure is greater than or equal to a preset threshold before initiating evaporative leak detection, thereby eliminating the interference of ambient pressure on evaporative leak detection.

[0043] 10) The manifold pressure is less than or equal to the corresponding preset threshold; During evaporative leak detection, if the manifold pressure is too high, fuel vapor may be drawn into the engine combustion chamber and prevented from being discharged to the outside world through the leak point, resulting in an unclear pressure gradient. Therefore, this embodiment ensures that the manifold pressure is less than or equal to the corresponding preset threshold before initiating evaporative leak detection, thereby eliminating the interference of high manifold pressure on evaporative leak detection.

[0044] 11) The vehicle speed is less than or equal to the corresponding preset threshold.

[0045] At excessively high vehicle speeds, the fuel evaporation system can distort the pressure gradient due to gas flow. Furthermore, engine temperature rapidly rises at high speeds, raising the overall ambient temperature of the fuel evaporation system, further complicating the pressure gradient. Therefore, this embodiment ensures that the vehicle speed is less than or equal to a preset threshold before initiating evaporative leak detection, thereby eliminating interference from high speeds on evaporative leak detection.

[0046] in, Figure 2 This diagram illustrates the process of performing a single-pass evaporative leak detection run, including: S21, determining whether the target vehicle meets the preset vehicle condition conditions for activating the evaporative leak detection process; if yes, executing S22; Specifically, in this step, the current vehicle condition information can be captured by the sensors of the target vehicle, so as to determine whether the target vehicle meets the preset vehicle condition conditions of the evaporative leak detection process based on the current vehicle condition information.

[0047] Among them, the specific parameters of the preset vehicle condition can be the ambient temperature, carbon canister load, fuel level, carbon canister flushing flow integral, engine starting water temperature, battery operating voltage, ambient pressure, fuel tank pressure, manifold pressure and vehicle speed introduced above, and no further examples will be given here.

[0048] In addition, if this step determines that the target vehicle fails to meet the preset vehicle condition conditions for activating the evaporative leak detection process, you can choose to end the entire diagnostic process, or wait for a period of time and then re-determine whether the preset vehicle condition conditions are met. This embodiment does not make specific limitations on this.

[0049] S22, closing the carbon canister ventilation valve of the target vehicle, and starting the carbon canister solenoid valve of the target vehicle to perform vacuum extraction, so as to adjust the fuel tank pressure of the target vehicle to a negative pressure.

[0050] Specifically, in this step, the engine control module (ECM) of the target vehicle can be used to control the closing of the carbon canister ventilation valve and start the carbon canister solenoid valve to perform vacuum extraction.

[0051] It should be noted that the executable program code of the above process is stored inside the engine control module. After the engine control module runs the executable program code, the above process can be completed without manual intervention.

[0052] S23, recording the pressure change gradient corresponding to the fuel tank pressure after being adjusted to negative pressure, wherein the pressure change gradient is used as the detection result of this evaporation leak detection process.

[0053] S103: If the target vehicle is in a cold engine start state during the execution of the first round of evaporative leak detection process, the operation of ignoring the first round of detection results is executed, and a second round of evaporative leak detection process is initiated for the fuel evaporative system.

[0054] The vehicle startup state described in this embodiment refers to the target vehicle's engine startup state. Engine startup states are categorized as cold-start and non-cold-start. A cold-start state refers to an engine startup after natural cooling and before it has completed preheating (reaching or approaching normal operating temperature); a non-cold-start state refers to an engine startup state after it has completed preheating. It should be understood that during the cold-start phase, the target vehicle's engine temperature rapidly rises, causing changes in the fuel vapor pressure within the fuel evaporation system. This change can affect the accuracy of evaporative leak detection. Therefore, after initiating the first round of evaporative leak detection, it is necessary to identify the vehicle startup state during the first round of evaporative leak detection to determine the validity of the first round's detection results.

[0055] As an example of identifying the vehicle startup status: In one implementation, if the first round of the evaporative leak detection process is initiated for the first time after a cold start, the first round of the evaporative leak detection process is determined to be in a cold start state during execution; otherwise, the first round of the evaporative leak detection process is determined to be in a non-cold start state of the target vehicle during execution. It should be noted that, in this case, one round of the evaporative leak detection process is sufficient to complete engine warm-up after a cold start. Therefore, during the process from engine startup to shutdown, except for the first round of the evaporative leak detection process, all other rounds of the evaporative leak detection process can be considered to be in a non-cold start state during execution.

[0056] In another implementation, the engine temperature and the ambient temperature of the target vehicle during the first round of execution of the evaporative leak detection process can be obtained; if the difference between the engine temperature and the ambient temperature of the target vehicle during the first round of execution of the evaporative leak detection process is less than or equal to a preset temperature threshold (the temperature maintained when the engine is not started will be significantly lower than the ambient temperature), it is determined that the target vehicle is in a cold engine start state during the first round of execution of the evaporative leak detection process; otherwise, it is determined that the target vehicle is in a non-cold engine start state during the first round of execution of the evaporative leak detection process.

[0057] In this embodiment, a second round of evaporation leak detection process may be initiated a preset time after the first round of evaporation leak detection process ends. For example, the second round of evaporation leak detection process may be initiated 30 seconds after the first round of evaporation leak detection process ends.

[0058] It should be understood that the time interval between the first and second evaporative leak detection processes is to reacquire the latest vehicle condition information of the target vehicle to determine whether it meets the preset vehicle condition conditions described above. If the reacquired vehicle condition information meets the preset vehicle condition conditions, the second evaporative leak detection process is initiated. Conversely, if the reacquired vehicle condition information does not meet the preset vehicle condition conditions, the entire diagnostic process can be terminated and a diagnostic failure notification can be reported through the on-board diagnostic system.

[0059] S104: Based on the second round of detection results, diagnose whether the fuel evaporation system has evaporation leakage.

[0060] In this embodiment, if the detection result of the second round of evaporative leakage detection process indicates that the pressure change gradient reaches the corresponding preset pressure change standard, it is determined that evaporative leakage occurs in the fuel evaporative system.

[0061] Based on the above, it can be seen that the pressure change gradient can reflect the rate of change of the fuel tank pressure within a certain period of time. If this rate of change is greater than a certain level, it indicates that there is a leak in the fuel evaporation system.

[0062] To this end, this embodiment can extract the rate of change of the fuel tank pressure from the second round of detection results (pressure change gradient). If the extracted rate of change reaches the corresponding preset threshold (i.e., reaches the preset pressure change standard), it is diagnosed that an evaporation leakage fault has occurred in the fuel evaporation system.

[0063] It should be noted that the above description is merely an illustrative introduction to the principle of diagnosing evaporative leaks based on pressure gradients. The specific diagnostic methods used in actual applications are not limited in this embodiment. As an example, a deep learning model can also be introduced to diagnose evaporative leaks. The diagnostic capabilities of the deep learning model can be trained using the pressure gradient characteristics of evaporative leak samples. It should be understood that any solution for diagnosing evaporative leaks based on pressure gradients falls within the scope of protection described in this specification.

[0064] In summary, the method of this embodiment initiates a first round of evaporative leak detection on the target vehicle. If the target vehicle is in a cold start state during the first round of evaporative leak detection, the corresponding test results are not used. Instead, a second round of evaporative leak detection is initiated to diagnose whether the fuel evaporation system has an evaporative leak fault based on the new test results. For the second round of evaporative leak detection, the previously initiated first round of evaporative leak detection can be regarded as an engine warm-up, thereby preventing the fuel tank pressure from being aggravated by the significant increase in engine temperature, which could lead to inaccurate evaporative leak diagnosis results. This can be particularly effective in vehicle maintenance scenarios, preventing inaccurate diagnostic results from misleading after-sales personnel in troubleshooting the problem.

[0065] The following describes the evaporation leakage diagnosis method of this embodiment in conjunction with specific application scenarios.

[0066] Application Scenario 1 Typically, the evaporative leak test process takes approximately 10 to 15 minutes to complete, while the engine warm-up time is approximately 2 to 3 minutes. This means that if the evaporative leak test process is initiated shortly after the vehicle is cold-started, the test results will be affected by the cold start state, resulting in reduced accuracy. However, after the evaporative leak test process is completed, the engine has been warmed up, and the evaporative leak test process initiated at this time has higher accuracy.

[0067] To this end, this application scenario attempts to initiate the first round of evaporative leak detection process for the target vehicle's fuel evaporative system. If the first round of evaporative leak detection process is not the first detection after the target vehicle is started with a cold engine, the fuel evaporative system is directly diagnosed based on the detection results of the first round. If the first round of evaporative leak detection process is the first detection after the target vehicle is started with a cold engine, the first round of evaporative leak detection process is allowed to complete normally. After the first round of evaporative leak detection process is completed, the second round of evaporative leak detection process is initiated to diagnose whether the fuel evaporative system has an evaporative leak based on the detection results of the second round. It should be noted that the first round of evaporative leak detection process is allowed to complete normally in order to leave time for the engine to warm up, so as to avoid executing the second round of evaporative leak detection process when the engine temperature has not yet stabilized.

[0068] Based on the above evaporative leak detection process processing strategy, if the target vehicle is started with a cold engine, the evaporative leak detection process needs to be performed twice. The whole process can be referred to Figure 3 Shown, including: S31, determining whether the target vehicle meets the preset vehicle condition conditions for activating the evaporative leak detection process; if yes, continuing to S32; if not, terminating the diagnosis early.

[0069] S32, initiates the first round (here represents the first time) of the evaporative leak detection process.

[0070] S33, determine whether the first round of evaporative leak detection process is completed; if yes, continue to execute S34; if not, wait for a preset time (such as 5 seconds) and then re-execute S33, and if S33 is re-executed a preset number of times (such as 3 times), end the diagnosis early. It should be noted that this application scenario requires the first round of evaporative leak detection to complete normally to ensure that the engine is preheated before the second round. If the first round of evaporative leak detection is interrupted (unsuccessfully completed), the entire diagnostic process is terminated.

[0071] S34, ignore the detection results of the first round.

[0072] S35, re-determine whether the target vehicle meets the preset vehicle condition conditions for activating the evaporative leak detection process; if yes, continue to execute S36; if not, end the diagnosis early.

[0073] S36, initiating a second round of evaporation leak detection process.

[0074] S37, determine whether the second round of evaporative leak detection process is completed; if yes, continue to execute S38; if not, wait for a preset time (such as 5 seconds) and then re-execute S37, and if S37 is re-executed a preset number of times (such as 3 times), end the diagnosis early.

[0075] S38: Based on the second round of detection results, diagnose whether an evaporation leakage fault occurs, and end the diagnosis normally.

[0076] Application Scenario 2 In this application scenario, during the execution of the first round of evaporative leak detection process, the vehicle start-up state of the first round of evaporative leak detection process is determined by comparing the engine temperature with the ambient temperature. If the target vehicle is in the cold engine start state, the second round of evaporative leak detection process is subsequently initiated; if the target vehicle is not in the cold engine start state, the evaporative leak fault is directly diagnosed based on the first round of detection results, and the second round of evaporative leak detection process is not subsequently initiated.

[0077] Here, it is assumed that the first round of evaporative leak detection process is initiated for the first time after the cold engine is started. The whole process can be referred to Figure 4 Shown, including: S41, determining whether the target vehicle meets the preset vehicle condition conditions for activating the evaporative leak detection process; if yes, continue to S42; if not, end the diagnosis early.

[0078] S42 , initiating a first round of evaporative leak detection process, and recording the engine temperature and ambient temperature of the target vehicle during the execution of the first round of evaporative leak detection process.

[0079] S43, determine whether the first round of evaporative leak detection process is successfully completed; if yes, continue to execute S44; if not, wait for a preset time (such as 5 seconds) and re-execute S43, and if S43 is restarted and executed a preset number of times (such as 3 times), end the diagnosis early.

[0080] S44, by comparing the engine temperature and ambient temperature of the first round, determine whether the first round of evaporative leakage detection process is in the cold engine start state of the target vehicle during execution; if yes, continue to execute S46; if not, execute S45.

[0081] Typically, the temperature of a preheated engine is higher than the ambient temperature. Therefore, if the engine temperature of the target vehicle during the first round of the evaporative leak detection process is less than or equal to the ambient temperature, or if the difference between the engine temperature and the ambient temperature is less than or equal to a first preset temperature threshold, the target vehicle is determined to be in a cold start state during the first round of the evaporative leak detection process. Otherwise, the target vehicle is determined to be in a non-cold start state during the first round of the evaporative leak detection process.

[0082] Furthermore, in extremely hot environments, even after engine preheating, the temperature will not be significantly higher than the ambient temperature. To more accurately identify the vehicle's startup state during the first round of evaporative leak detection, a preset adjustment coefficient (determined based on the absolute difference between the target vehicle's engine temperature and the reference ambient temperature) can be introduced to dynamically adjust the first preset temperature threshold when the ambient temperature exceeds a second preset temperature threshold (a temperature greater than the second preset temperature threshold indicates an extremely hot environment). The first preset temperature threshold and the preset adjustment coefficient are negatively correlated, and the corresponding expression can be as follows: ; Indicates: the adjusted first preset temperature threshold; Indicates: the first preset temperature threshold before adjustment; Indicates: the current ambient temperature of the target vehicle; Indicates: Reference ambient temperature, generally adopts the value of normal ambient temperature; Indicates: Environmental sensitivity coefficient, which can be customized according to needs; Indicates: preset adjustment coefficient, directly taking the absolute value difference between the target vehicle's engine temperature and the reference ambient temperature as the value of the preset adjustment coefficient.

[0083] Here, it is assumed that the first preset temperature threshold before adjustment is 8℃, the second preset temperature threshold is 50℃, then at the current ambient temperature If the temperature does not reach 50°C, during the first round of evaporative leak detection, the engine temperature of the target vehicle is higher than the current ambient temperature. , and the temperature difference reaches 8°C, it can be determined that the target vehicle is in a non-cold engine start state during the execution of the first round of evaporative leakage detection process; otherwise, it is determined that the target vehicle is in a cold engine start state.

[0084] However, if the current ambient temperature Reaching 70°C (exceeding the second preset temperature threshold), the first preset temperature threshold of 8°C Need to adjust the coefficient according to the preset Here we assume that the reference ambient temperature is 20℃, and the environmental sensitivity coefficient is is 0.0 1, then the adjusted first preset temperature threshold =6°C, that is, the engine temperature of the target vehicle is greater than the current ambient temperature, and the temperature difference only needs to reach 6°C (less than 8°C before adjustment) to determine that the target vehicle is in a non-cold engine start state during the execution of the first round of evaporative leak detection process.

[0085] Based on the above mechanism: in normal environments, during the first round of the evaporative leak detection process, the engine temperature must be significantly higher than the ambient temperature to be considered complete for preheating, thereby confirming that the target vehicle is in a non-cold start state during the first round of the evaporative leak detection process. In extremely hot environments, the engine temperature only needs to be slightly higher than the ambient temperature to be considered complete for preheating, thereby confirming that the target vehicle is in a non-cold start state during the first round of the evaporative leak detection process. This dynamic adjustment can better adapt to the recognition of vehicle startup status in different environmental conditions, thereby ensuring the accuracy and reliability of the evaporative leak detection process.

[0086] It should be noted that the above expression formula is only used to exemplify the mathematical relationship that the first preset temperature threshold and the preset adjustment coefficient are negatively correlated. Under this negative correlation mathematical relationship, any adjustment of the expression formula should fall within the scope of protection of this embodiment.

[0087] S45: Based on the first round of detection results, diagnose whether an evaporation leakage fault occurs, and end the diagnosis normally.

[0088] S46, re-determine whether the target vehicle meets the preset vehicle condition conditions for activating the evaporative leak detection process; if yes, continue to S47; if not, end the diagnosis early.

[0089] S47, initiate the second round of evaporation leak detection process.

[0090] S48, determine whether the second round of evaporative leak detection process is completed; if yes, continue to execute S49; if not, wait for a preset time (such as 5 seconds) and re-execute S48, and if S48 is restarted and executed a preset number of times (such as 3 times), end the diagnosis early.

[0091] S49: Based on the second round of detection results, diagnose whether an evaporation leakage fault occurs, and end the diagnosis normally.

[0092] It should be understood that in application scenario one, the target vehicle performs a two-round evaporative leak detection process by default. The first round is used for the engine preheating stage, while the second round of detection results is used to diagnose the evaporative leak fault. The advantage of this design is that there is no need to introduce additional complex programs or algorithms on the target vehicle to determine whether the engine has completed preheating, thereby reducing the difficulty of implementation. In contrast, application scenario two uses a more accurate temperature comparison method (comparison between engine temperature and ambient temperature) to determine whether the engine has completed preheating. If the engine has been preheated, the first round of detection results can be used directly to diagnose the evaporative leak fault, without the need to execute the second round of evaporative leak detection process, thereby improving diagnostic efficiency.

[0093] In addition, corresponding to Figure 1 In addition to the method shown, another embodiment of the present application further provides a diagnostic device for evaporative leakage. Figure 5 FIG. 5 is a schematic structural diagram of the diagnostic device 500, comprising: The detection execution module 510 is used to initiate a first round of evaporative leak detection process for the fuel evaporation system of the target vehicle.

[0094] The detection decision module 530 is configured to ignore the detection results of the first round of detection if the engine is in a cold engine start state during the execution of the first round of the evaporative leak detection process, and initiate a second round of the evaporative leak detection process for the fuel evaporative system.

[0095] The diagnosis execution module 540 is configured to diagnose whether evaporation leakage occurs in the fuel evaporation system based on the detection result of the second round.

[0096] Optionally, the detection decision module 530 is also used to: if the first round of the evaporative leakage detection process is initiated for the first time after the cold engine start, determine that the first round of the evaporative leakage detection process is in the cold engine start state of the target vehicle during execution; otherwise, determine that the first round of the evaporative leakage detection process is in the non-cold engine start state of the target vehicle during execution.

[0097] Optionally, the detection decision module 530 is also used to: obtain the engine temperature and the ambient temperature of the target vehicle during the execution of the evaporative leakage detection process in the first round; if the difference between the engine temperature and the ambient temperature is less than or equal to a first preset temperature threshold, determine that the target vehicle is in a cold engine start state during the execution of the evaporative leakage detection process in the first round, otherwise determine that the target vehicle is in a non-cold engine start state during the execution of the evaporative leakage detection process in the first round; wherein, when the ambient temperature is greater than the second preset temperature threshold, the first preset temperature threshold is negatively correlated with a preset adjustment coefficient, and the value of the preset adjustment coefficient is determined based on the absolute value difference between the engine temperature and the reference ambient temperature.

[0098] Optionally, when the ambient temperature is greater than a second preset temperature threshold, the first preset temperature threshold is negatively correlated with a preset adjustment coefficient, and the value of the preset adjustment coefficient is the absolute value difference between the engine temperature of the target vehicle and the reference ambient temperature.

[0099] Optionally, after determining the vehicle startup state in which the evaporation leakage detection process of the first round is executed, the diagnostic execution module 540 is further used to: if the evaporation leakage detection process of the first round is in a hot engine startup state during execution, then based on the detection results of the first round, diagnose whether evaporation leakage occurs in the fuel evaporation system.

[0100] Optionally, the evaporative leak detection process includes: adjusting the fuel tank pressure of the target vehicle to a negative pressure, and recording a pressure change gradient corresponding to the fuel tank pressure after being adjusted to the negative pressure; wherein the pressure change gradient serves as a detection result of the evaporative leak detection process.

[0101] Optionally, the diagnostic execution module 540 diagnoses whether evaporation leakage occurs in the fuel evaporation system based on the detection results of the second round, including: if the detection results of the evaporation leakage detection process of the second round indicate that the pressure change gradient reaches a corresponding preset pressure change standard, then determining that evaporation leakage occurs in the fuel evaporation system.

[0102] Optionally, adjusting the fuel tank pressure of the target vehicle to a negative pressure includes: closing the carbon canister ventilation valve of the target vehicle, and starting the carbon canister solenoid valve of the target vehicle to perform vacuum extraction to adjust the fuel tank pressure of the target vehicle to a negative pressure.

[0103] Optionally, the diagnostic execution module 540 diagnoses whether evaporation leakage occurs in the fuel evaporation system based on the detection results of the second round, including: if the detection results of the evaporation leakage detection process of the second round indicate that the pressure change gradient reaches a corresponding preset pressure change standard, then determining that evaporation leakage occurs in the fuel evaporation system.

[0104] Optionally, the evaporative leak detection process is performed when the target vehicle meets a preset vehicle condition; the preset vehicle condition includes at least one of the following: The ambient temperature is within the corresponding reasonable range; The preset gross leakage fault did not occur; The carbon canister load is within the corresponding reasonable range; The fuel level is within the corresponding reasonable range; The carbon canister flushing flow integral is greater than or equal to the corresponding preset threshold; The engine starting water temperature is within the corresponding reasonable range; The battery operating voltage is within the corresponding reasonable range; The fuel tank pressure is within the corresponding reasonable range; The ambient pressure is greater than or equal to the corresponding preset threshold; The manifold pressure is less than or equal to the corresponding preset threshold; The vehicle speed is less than or equal to the corresponding preset threshold.

[0105] In summary, the device of this embodiment initiates a first round of evaporative leak detection on the target vehicle. If the first round of evaporative leak detection is in the cold engine start state during execution, the corresponding test results are not used, and a second round of evaporative leak detection is re-initiated to diagnose whether the fuel evaporation system has an evaporative leak fault based on the new test results. For the second round of evaporative leak detection, the previously initiated first round of evaporative leak detection can be regarded as an engine warm-up, thereby preventing the fuel tank pressure from being aggravated by the significant engine temperature increase, which could lead to inaccurate evaporative leak diagnosis. This can be particularly effective in vehicle maintenance scenarios to prevent after-sales personnel from misleading the problem.

[0106] It should be noted that, regarding the diagnostic device in the above embodiment, the specific manner in which each unit performs operations has been described in detail in the embodiment of the method, and will not be elaborated on here.

[0107] In addition, another embodiment of the present application provides a vehicle. Figure 66 is a schematic structural diagram of the vehicle, including a memory 601 and a processor 602, wherein the memory 601 stores an executable program code 6011, and the processor 602 is used to call and execute the executable program code 6011 to perform an evaporative leakage diagnosis method provided in the above embodiment.

[0108] This embodiment can divide the vehicle into functional modules based on the above-described method example. For example, each functional module can be mapped to a specific function, or two or more functions can be integrated into a single processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used.

[0109] When functional modules are divided according to their functions, the vehicle may include a detection execution module, a state determination module, a detection decision module, and a diagnosis execution module. It should be noted that all relevant details of the steps involved in the above method embodiments can be referenced in the functional descriptions of the corresponding functional modules and will not be repeated here.

[0110] It should be understood that the vehicle provided in this embodiment is used to execute the above-mentioned evaporative leakage diagnosis method, and thus can achieve the same effect as the above-mentioned implementation method.

[0111] In the case of an integrated unit, the vehicle may include a processing module and a storage module. The processing module may be used to control and manage the vehicle's movements, while the storage module may be used to support the vehicle's execution of program codes and data.

[0112] The processing module may be a processor or controller that implements or executes the various exemplary logic blocks, modules, and circuits disclosed herein. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processing (DSP) and a microprocessor, and the storage module may be a memory.

[0113] In addition, another embodiment of the present application further provides a computer-readable storage medium, which stores computer program code. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement a diagnostic method for evaporative leakage provided by the above-mentioned embodiment.

[0114] Among them, the beneficial effects of the above embodiments can refer to the beneficial effects of the corresponding methods provided above, and will not be repeated here.

[0115] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0116] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, 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.

[0117] In the description of the present disclosure, it should be understood that if the terms "up", "down", "front", "back", "left" and "right" are used to indicate directions or positional relationships, they are based on the directions or positional relationships shown in the accompanying drawings. They are only used to facilitate the description of the present invention and simplify the description, and do not indicate or imply that the positions or elements referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limitations of the present disclosure.

[0118] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. It should also be noted that the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, commodity, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, commodity, or device comprising the element.

[0119] The above are merely examples of the present disclosure and are not intended to limit the present disclosure. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure are intended to be included within the scope of the claims of the present disclosure.

Claims

1. A method for diagnosing evaporative leakage, characterized in that: include: Initiate the first round of evaporative leak detection process for the target vehicle's fuel evaporative system; If the target vehicle is in a cold engine start state during the execution of the first round of the evaporative leak detection process, ignoring the first round of detection results and initiating a second round of the evaporative leak detection process for the fuel evaporation system; And, based on the detection result of the second round, diagnosing whether evaporation leakage occurs in the fuel evaporation system.

2. The method according to claim 1, characterized in that Also includes: If the first round of the evaporative leak detection process is initiated for the first time after a cold engine start, it is determined that the first round of the evaporative leak detection process is in a cold engine start state of the target vehicle; otherwise, it is determined that the first round of the evaporative leak detection process is in a non-cold engine start state of the target vehicle.

3. The method according to claim 1, characterized in that Also includes: Obtaining an engine temperature and an ambient temperature of the target vehicle during execution of the evaporative leak detection process in the first round; If the difference between the engine temperature and the ambient temperature is less than or equal to a first preset temperature threshold, determining that the target vehicle is in a cold engine start state during the execution of the first round of the evaporative leak detection process; otherwise, determining that the target vehicle is in a non-cold engine start state during the execution of the first round of the evaporative leak detection process; Among them, when the ambient temperature is greater than the second preset temperature threshold, the first preset temperature threshold is negatively correlated with the preset adjustment coefficient, and the value of the preset adjustment coefficient is determined based on the absolute value difference between the engine temperature and the reference ambient temperature.

4. The method according to claim 1 or 2, characterized in that After determining the vehicle startup state during the execution of the first round of the evaporative leak detection process, the method further includes: If the first round of evaporative leakage detection process is executed in a non-cold engine start state, whether evaporative leakage occurs in the fuel evaporative system is diagnosed based on the first round of detection results.

5. The method according to claim 1, wherein The evaporative leak detection process includes: The fuel tank pressure of the target vehicle is adjusted to a negative pressure, and the pressure change gradient corresponding to the fuel tank pressure after being adjusted to the negative pressure is recorded; wherein the pressure change gradient is used as the detection result of the evaporative leak detection process.

6. The method according to claim 5, characterized in that The diagnosing whether evaporation leakage occurs in the fuel evaporation system based on the second round of detection results includes: If the detection result of the second round of the evaporation leakage detection process indicates that the pressure change gradient reaches the corresponding preset pressure change standard, it is determined that evaporation leakage occurs in the fuel evaporation system.

7. The method according to any one of claims 1 to 6, characterized in that The evaporative leak detection process is performed when the target vehicle meets a preset vehicle condition; the preset vehicle condition includes at least one of the following: The ambient temperature is within the corresponding reasonable range; The preset gross leakage fault did not occur; The carbon canister load is within the corresponding reasonable range; The fuel level is within the corresponding reasonable range; The carbon canister flushing flow integral is greater than or equal to the corresponding preset threshold; The engine starting water temperature is within the corresponding reasonable range; The battery operating voltage is within the corresponding reasonable range; The fuel tank pressure is within the corresponding reasonable range; The ambient pressure is greater than or equal to the corresponding preset threshold; The manifold pressure is less than or equal to the corresponding preset threshold; The vehicle speed is less than or equal to the corresponding preset threshold.

8. A diagnostic device for evaporative leakage, characterized in that: include: A detection execution module, used to initiate a first round of evaporative leak detection process for the fuel evaporative system of the target vehicle; a detection decision module, configured to, if the target vehicle is in a cold engine start state during the execution of the first round of the evaporative leak detection process, ignore the detection results of the first round and initiate a second round of the evaporative leak detection process for the fuel evaporative system; The diagnosis execution module is configured to diagnose whether evaporation leakage occurs in the fuel evaporation system based on the detection result of the second round.

9. A vehicle, characterized in that: include: a memory for storing executable program code; A processor is configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

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