Desorption system monitoring method, apparatus, device, and storage medium

Abstract

The present disclosure provides a desorption system monitoring method, device, equipment and storage medium. The method comprises: determining that the desorption system meets the diagnostic condition, determining the first duration that the tank pressure is in a falling state when the desorption system is in a desorption working condition; then determining the working state of the desorption system according to the first duration, the second duration that the carbon canister solenoid valve is in an open state and the control duty cycle of the carbon canister solenoid valve. The present disclosure solves the problem that the tank cannot accurately monitor the desorption system condition without affecting driving in the prior art, accurately monitors the fuel evaporation desorption system without affecting the mixed gas control and effectively determines the working state of the carbon canister solenoid valve according to the specific pressure change condition without the need for additional active control of the working state of the carbon canister solenoid valve.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, and in particular to a method, apparatus, equipment and storage medium for monitoring a desorption system. Background Technology

[0002] Vehicles equipped with gasoline engines have fuel tanks filled with a large amount of oil vapor due to the volatility of gasoline. During engine operation, this oil vapor is typically introduced into the engine intake manifold through a fuel evaporation system consisting of the fuel tank, charcoal canister (which contains a charcoal canister vent valve, charcoal canister solenoid valve, or equivalent devices such as an air pump), charcoal canister solenoid valve, and several pipelines. It then enters the engine cylinders for combustion along with the intake airflow, improving fuel economy and preventing large amounts of oil vapor from leaking into the atmosphere and polluting the environment. To prevent oil vapor leakage, real-time monitoring of the fuel evaporation system is necessary for timely maintenance.

[0003] In real-time detection of oil vapor leakage in the fuel evaporation system, it is necessary to specifically monitor the flow rate of the desorption system within the fuel evaporation system to ensure that there are no structural faults in the desorption system. The desorption system refers to the section from the charcoal canister solenoid valve to the engine intake manifold, and is used to desorb the vapor adsorbed in the charcoal canister into the engine intake manifold to participate in combustion.

[0004] Existing methods for monitoring desorption systems primarily rely on pressure changes in the pipelines on the engine side to determine whether the desorption system is functioning properly. This necessitates actively controlling the structure within the desorption system, which in turn affects the stability of the vehicle during normal operation. Summary of the Invention

[0005] This disclosure provides a method, apparatus, equipment, and storage medium for monitoring a desorption system, in order to solve the problem that the status of the desorption system cannot be accurately monitored inside the fuel tank without affecting driving.

[0006] Firstly, this disclosure provides a method for monitoring a desorption system, the method comprising:

[0007] The desorption system is determined to meet the diagnostic criteria. The desorption system includes high-load desorption pipelines and low-load desorption pipelines. The diagnostic criteria include the diagnostic criteria corresponding to the high-load desorption pipelines and the diagnostic criteria corresponding to the low-load desorption pipelines.

[0008] If the desorption system is in desorption mode, determine the first duration during which the tank pressure is decreasing;

[0009] The operating state of the desorption system is determined based on the first duration, the second duration during which the charcoal canister solenoid valve is in the open state, and the control duty cycle of the charcoal canister solenoid valve.

[0010] Optional diagnostic conditions for high-load desorption lines include: no faults in the canister solenoid valve and fuel tank pressure sensor; turbocharger boost pressure and intake manifold pressure both exceed the corresponding limits; and engine load variation and throttle opening variation both fall below the corresponding limits. Diagnostic conditions for low-load desorption lines include: no faults in the canister solenoid valve and fuel tank pressure sensor; intake manifold pressure is within the set range; and engine load variation and throttle opening variation both fall below the corresponding limits.

[0011] Optionally, if the desorption system is in desorption mode, determining the first duration for which the tank pressure is decreasing includes: determining that the desorption system is in desorption mode; determining the tank pressure at the current moment and the tank pressure at the previous moment; if the tank pressure at the previous moment is higher than the tank pressure at the current moment, determining that the tank pressure is decreasing, and incrementing the timer corresponding to the first duration; determining the timer duration when the duration of the desorption mode reaches the desorption mode duration limit as the first duration, and the desorption mode duration limit as the second duration.

[0012] Optionally, the operating state of the desorption system is determined based on the first duration, the second duration during which the charcoal canister solenoid valve is in the open state, and the control duty cycle of the charcoal canister solenoid valve. This includes: determining that when the total duration of the desorption operation reaches the second duration, the control duty cycle of the charcoal canister solenoid valve is a constant value; using the ratio of the first duration to the second duration as the pressure drop time percentage; and determining the operating state of the desorption system based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle and a set threshold.

[0013] Optionally, after determining that the desorption system meets the diagnostic conditions, the method further includes: if the desorption system is not in desorption mode, recording the duration of non-desorption mode and real-time tank pressure; and determining the minimum real-time tank pressure when the duration of non-desorption mode reaches the corresponding duration threshold.

[0014] Optionally, the operating status of the desorption system can be determined based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle and a set threshold, including: if the absolute value of the difference is less than the set threshold, the desorption system is determined to be in normal operating condition; if the absolute value of the difference is greater than or equal to the set threshold, the desorption system is determined to have an abnormal operating condition; and the specific type of the abnormal operating condition is determined based on the diagnostic condition type, the real-time minimum oil tank pressure, and the set pressure threshold.

[0015] Optionally, based on the diagnostic condition type, the real-time minimum tank pressure, and the set pressure threshold, the specific type of abnormal operating condition is determined, including: If the diagnostic condition type is high-load desorption pipeline, the diagnostic conditions are as follows: If the real-time minimum tank pressure is higher than the set pressure threshold, the specific type of abnormal operating condition is determined to be high-load desorption flow failure and the charcoal canister solenoid valve is stuck and normally closed; if the real-time minimum tank pressure is lower than the set pressure threshold, the specific type of abnormal operating condition is determined to be high-load desorption flow failure and the charcoal canister solenoid valve is stuck and normally open. If the diagnostic condition type is low-load desorption pipeline, the diagnostic conditions are as follows: If the real-time minimum tank pressure is higher than the set pressure threshold, the specific type of abnormal operating condition is determined to be low-load desorption flow failure and the charcoal canister solenoid valve is stuck and normally closed; if the real-time minimum tank pressure is lower than the set pressure threshold, the specific type of abnormal operating condition is determined to be low-load desorption flow failure and the charcoal canister solenoid valve is stuck and normally open.

[0016] Optionally, the operating state of the desorption system is determined based on the first duration, the second duration during which the charcoal canister solenoid valve is in the open state, and the control duty cycle of the charcoal canister solenoid valve. This includes: determining that when the total duration of the desorption condition reaches the second duration, the control duty cycle of the charcoal canister solenoid valve is a non-constant value; exiting the desorption system operating state diagnosis process until the diagnosis conditions are met again.

[0017] Secondly, this disclosure provides a desorption system monitoring device, which includes:

[0018] The diagnostic module is used to determine whether the desorption system meets the diagnostic conditions. The desorption system includes high-load desorption pipelines and low-load desorption pipelines. The diagnostic conditions include the diagnostic conditions corresponding to the high-load desorption pipelines and the diagnostic conditions corresponding to the low-load desorption pipelines.

[0019] The calculation module is used to determine the first duration of the tank pressure drop when the desorption system is in desorption mode;

[0020] The determination module is used to determine the working state of the desorption system based on the first duration, the second duration during which the charcoal canister solenoid valve is in the open state, and the control duty cycle of the charcoal canister solenoid valve.

[0021] Optionally, the diagnostic module specifically includes diagnostic conditions for the high-load desorption pipeline, including: the charcoal canister solenoid valve and fuel tank pressure sensor are not faulty; the turbocharger boost pressure and intake manifold pressure are both higher than the corresponding limits; the engine load change and throttle opening change are both lower than the corresponding limits; and diagnostic conditions for the low-load desorption pipeline, including: the charcoal canister solenoid valve and fuel tank pressure sensor are not faulty; the intake manifold pressure is within the set range; and the engine load change and throttle opening change are both lower than the corresponding limits.

[0022] Optionally, the calculation module is specifically used to: determine that the desorption system is in desorption mode; determine the tank pressure at the current moment and the tank pressure at the previous moment; if the tank pressure at the previous moment is higher than the tank pressure at the current moment, determine that the tank pressure is in a decreasing state, and increase the timer corresponding to the first duration; determine the timer duration for which the duration of the desorption mode reaches the desorption mode duration limit as the first duration, and the desorption mode duration limit is the second duration.

[0023] Optionally, the determining module is specifically used to determine that when the total duration of the desorption condition reaches the second duration, the control duty cycle of the charcoal canister solenoid valve is a constant value; the ratio of the first duration to the second duration is used as the pressure drop time percentage; and the working state of the desorption system is determined based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle of the charcoal canister solenoid valve and a set threshold.

[0024] Optionally, the determination module is also used to, after determining that the desorption system meets the diagnostic conditions, if the desorption system is not in the desorption condition, record the duration of the non-desorption condition and the real-time tank pressure; and determine the minimum real-time tank pressure when the duration of the non-desorption condition reaches the corresponding duration threshold.

[0025] Optionally, the determination module is specifically used to: determine that the desorption system is in normal working condition if the absolute value of the difference is less than a set threshold; determine that the desorption system has an abnormal operating condition if the absolute value of the difference is greater than or equal to the set threshold; and determine the specific type of the abnormal operating condition based on the diagnostic condition type, the real-time minimum oil tank pressure and the set pressure threshold.

[0026] Optionally, the determination module is specifically used for the following: If the diagnostic condition type is for a high-load desorption pipeline, and the corresponding diagnostic condition is: if the real-time minimum oil tank pressure is higher than the set pressure threshold, the specific type of abnormal operating condition is determined to be a high-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally closed; if the real-time minimum oil tank pressure is lower than the set pressure threshold, the specific type of abnormal operating condition is determined to be a high-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally open. If the diagnostic condition type is for a low-load desorption pipeline, and the corresponding diagnostic condition is: if the real-time minimum oil tank pressure is higher than the set pressure threshold, the specific type of abnormal operating condition is determined to be a low-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally closed; if the real-time minimum oil tank pressure is lower than the set pressure threshold, the specific type of abnormal operating condition is determined to be a low-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally open.

[0027] Optionally, the determination module is specifically used to determine that when the total duration of the desorption condition reaches the second duration, the control duty cycle of the carbon canister solenoid valve is a non-constant value; exit the desorption system working status diagnosis process until the diagnosis conditions are met again.

[0028] Thirdly, this disclosure also provides a control device, which includes:

[0029] At least one processor;

[0030] and memory that is communicatively connected to at least one processor;

[0031] The memory stores instructions that can be executed by at least one processor to cause the control device to perform a desorption system monitoring method as described in any embodiment of the first aspect of this disclosure.

[0032] Fourthly, this disclosure also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement a desorption system monitoring method as described in any of the first aspects of this disclosure.

[0033] The desorption system monitoring method, apparatus, equipment, and storage medium disclosed herein determine the desorption system's operating condition by confirming that the system meets diagnostic criteria and, when the system is in desorption mode, determining the first duration during which the fuel tank pressure is decreasing. Then, based on the first duration, the second duration during which the charcoal canister solenoid valve is open, and the control duty cycle of the charcoal canister solenoid valve, the operating state of the desorption system is determined. Therefore, by monitoring changes in fuel tank pressure, the fuel vapor desorption system can be accurately monitored without requiring additional active control of the charcoal canister solenoid valve's operating state or affecting the air-fuel mixture control. Furthermore, the operating state of the charcoal canister solenoid valve can be effectively determined based on specific pressure changes. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0035] Figure 1 This is an application scenario diagram of the desorption system monitoring method provided in the embodiments of this disclosure;

[0036] Figure 2 A flowchart illustrating a desorption system monitoring method provided in one embodiment of this disclosure;

[0037] Figure 3a A flowchart illustrating a desorption system monitoring method provided in yet another embodiment of this disclosure;

[0038] Figure 3b for Figure 3a The flowchart of the method for determining the working state of the desorption system based on a set threshold provided in the embodiment shown is as follows:

[0039] Figure 4 A schematic diagram of the structure of a desorption system monitoring device provided in yet another embodiment of this disclosure;

[0040] Figure 5This is a schematic diagram of the structure of a control device provided in yet another embodiment of this disclosure.

[0041] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0043] The following is a description of the terminology used in this disclosure:

[0044] Fuel vaporization system: This system comprises the equipment and components through which gasoline vapors reside and pass from the fuel tank to the engine intake manifold. It includes, in sequence, the fuel tank (or fuel tank assembly), charcoal canister (or charcoal canister assembly), charcoal canister vent valve (or equivalent device, such as an air pump), charcoal canister solenoid valve, connecting pipes, and the engine intake manifold. The charcoal canister absorbs gasoline vapors, preventing them from being released into the air. The charcoal canister vent valve seals the connection between the charcoal canister and the outside air and can be used to monitor for leaks in the fuel vaporization system. The charcoal canister solenoid valve controls the ventilation between the charcoal canister and the engine.

[0045] Desorption System: The desorption system refers to the section from the charcoal canister solenoid valve to the engine intake manifold. It includes the high-load desorption line from the charcoal canister solenoid valve through a venturi tube to the engine intake manifold, and the low-load desorption line from the charcoal canister solenoid valve directly to the engine intake manifold. The former primarily desorbs adsorbed vapors from the charcoal canister into the engine intake manifold to participate in combustion when the engine turbocharger is pressurizing, while the latter primarily desorbs adsorbed vapors from the charcoal canister into the engine intake manifold to participate in combustion when the engine turbocharger is not pressurizing.

[0046] The technical solutions of this disclosure and how they solve the aforementioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0047] Vehicles equipped with gasoline engines experience significant oil vapor buildup in their fuel evaporation systems due to the volatility of gasoline. To prevent oil vapor leakage, real-time monitoring of this system is crucial for timely repairs. This real-time monitoring requires dedicated flow monitoring of the desorption system within the fuel evaporation system to ensure there are no structural faults. The desorption system (which represents the section from the charcoal canister solenoid valve to the engine intake manifold, used to desorb vapors adsorbed in the charcoal canister and release them into the engine intake manifold for combustion) is functioning correctly. However, current methods for determining the desorption system's operational status typically involve actively controlling the opening of the charcoal canister solenoid valve and analyzing pressure changes in the intake manifold before and after its opening and closing.

[0048] However, this method will affect the working state of the charcoal canister solenoid valve during normal vehicle operation (because the charcoal canister solenoid valve needs to be fully opened and closed, so it needs to be actively controlled, otherwise the diagnostic conditions cannot be met at all). When the charcoal canister solenoid valve is fully open and closed, if the gas concentration in the charcoal canister is high, it will cause the mixture to fluctuate in the fuel evaporation system, and at the same time cause the whole vehicle to shake, affecting the vehicle's driving safety.

[0049] To address the aforementioned issues, this disclosure provides a desorption system monitoring method. Based on the correlation between changes in tank pressure under desorption conditions and the normal opening and closing states of the charcoal canister solenoid valve, the operating state of the desorption system is determined. Thus, the operating state of the desorption system can be effectively determined without adding additional structures or affecting the normal driving state of the vehicle.

[0050] The application scenarios of the embodiments of this disclosure are explained below:

[0051] Figure 1 This diagram illustrates an application scenario of the desorption system monitoring method provided in this embodiment of the disclosure. Figure 1 As shown, the fuel evaporation system 100 includes a fuel tank 101, a charcoal canister 102, a charcoal canister vent valve 103, and a charcoal canister solenoid valve 104 connected in sequence. A vent shut-off valve 105 is provided at the fuel tank port. In addition, a pressure sensor 106 is provided inside the fuel tank or at the connection between the fuel tank and the charcoal canister.

[0052] The charcoal canister solenoid valve 104 is connected to the intake manifold 111 of the engine 110 via a one-way valve and a first connecting pipe 107, and is also connected to the venturi tube 112 of the engine 110 via a one-way valve and a second connecting pipe 108. The venturi tube 112 is then connected to the intake manifold 111. The part from the charcoal canister solenoid valve 104 to the intake manifold 111 and the venturi tube 112 constitutes the desorption system (as shown in Figure 120). During the desorption system diagnostic process, by allowing oil vapor in the fuel vaporization system 100 to enter the engine 110 through the desorption system while the charcoal canister solenoid valve 104 is operating normally, and by detecting the pressure change during this process using the pressure sensor 106, the operating status of the desorption system can be determined.

[0053] It should be noted that, Figure 1 The scenario shown uses only one pressure sensor as an example, but this disclosure is not limited to this; that is, the number of pressure sensors can be arbitrary.

[0054] The following detailed description of the desorption system monitoring method provided in this disclosure is based on specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0055] Figure 2 This is a flowchart illustrating a desorption system monitoring method provided in one embodiment of this disclosure. Figure 2 As shown, it includes the following steps:

[0056] Step S201: Determine that the desorption system meets the diagnostic criteria.

[0057] The desorption system includes high-load desorption pipelines and low-load desorption pipelines, and the diagnostic conditions include diagnostic conditions corresponding to high-load desorption pipelines and diagnostic conditions corresponding to low-load desorption pipelines.

[0058] Specifically, leak detection of the fuel evaporation system is generally performed while the vehicle is in motion or the engine is running. Only when the engine is running can it draw in fuel vapor from the fuel evaporation system through the engine intake manifold, allowing for leak detection using the engine intake manifold vacuum method. Desorption system testing is also performed while the engine is running.

[0059] Before testing the desorption system, it is necessary to ensure that the current operating conditions meet the diagnostic requirements, such as that the charcoal canister solenoid valve, fuel tank pressure sensor and other structures are functioning properly, and that the pressure of each part meets the set value. This ensures that the gas in the fuel evaporation system can pass through the desorption system normally and that the fuel tank pressure sensor's test results are correct, so as to accurately determine the working status of the desorption system.

[0060] Since the high-load desorption line and low-load desorption line in the desorption system operate under the conditions of no pressurization and pressurization respectively, it is necessary to determine the corresponding diagnostic conditions based on the high-load desorption line and the low-load desorption line. The main difference is the operating condition of the pressurizer and the corresponding pressure change in the intake manifold (when the high-load desorption line is working, the pressure in the intake manifold will be higher due to the action of the pressurizer).

[0061] After determining the diagnostic conditions that the desorption system must meet, the diagnostic process for the corresponding part of the desorption pipeline can be initiated based on the type of diagnostic conditions met.

[0062] Step S202: If the desorption system is in desorption mode, determine the first duration during which the oil tank pressure is in a decreasing state.

[0063] Specifically, when the desorption system is in desorption mode, meaning gas flows from the charcoal canister through the system to the engine, the charcoal canister solenoid valve is open. Because the solenoid valve periodically opens and closes at a certain frequency, it controls the flow of gas (or gas-liquid mixture) into the engine, ensuring a relative pressure balance between the fuel vaporization system and the engine. When the solenoid valve is open, gas in the fuel tank passes through the charcoal canister and desorption system sequentially into the engine under vacuum, causing a continuous decrease in fuel tank pressure. This pressure then rises again after the solenoid valve closes.

[0064] Therefore, by statistically analyzing the ratio of the duration of the oil tank pressure in a decreasing state (i.e., the first duration) to the duration of the desorption operation, and comparing it with the control duty cycle of the charcoal canister solenoid valve in the open state (i.e., the ratio of the actual opening time to the total opening time), it can be determined whether the desorption system is in normal working condition.

[0065] The first time duration statistical method can directly obtain the changes in tank pressure at continuous moments, and take the time of pressure drop as the first time duration.

[0066] Step S203: Determine the working state of the desorption system based on the first duration, the second duration during which the charcoal canister solenoid valve is in the open state, and the control duty cycle of the charcoal canister solenoid valve.

[0067] Specifically, the second duration is the duration of the desorption operation. Therefore, by comparing the ratio of the first duration to the second duration with the control duty cycle, it can be determined whether the oil tank pressure drops synchronously when the charcoal canister solenoid valve is in the open state. If the oil tank pressure drops synchronously, it indicates that the desorption system is working normally. If the ratio of the first duration to the second duration of the oil tank pressure drop is less than the control duty cycle, there may be a charcoal canister solenoid valve malfunction (possibly a malfunction that occurs during the diagnostic process) or a change in the working state of the charcoal canister solenoid valve (such as a change in its operating state). Therefore, by comparing the first duration, the second duration, and the control duty cycle, the working state of the desorption system can be quickly determined.

[0068] The desorption system monitoring method provided in this disclosure determines the desorption system by confirming that it meets diagnostic conditions. When the desorption system is in desorption mode, it determines the first duration during which the fuel tank pressure is decreasing. Then, based on the first duration, the second duration during which the charcoal canister solenoid valve is open, and the control duty cycle, it determines the operating state of the desorption system. Therefore, by monitoring changes in fuel tank pressure, the fuel vapor desorption system can be accurately monitored without requiring additional active control of the charcoal canister solenoid valve or affecting the air-fuel mixture control. Furthermore, the operating state of the charcoal canister solenoid valve can be effectively determined based on specific pressure changes.

[0069] Figure 3a This is a flowchart illustrating a desorption system monitoring method provided in this disclosure. Figure 3a As shown, the desorption system monitoring method provided in this embodiment includes the following steps:

[0070] Step S301: Determine that the desorption system meets the diagnostic criteria.

[0071] The desorption system includes high-load desorption pipelines and low-load desorption pipelines, and the diagnostic conditions include diagnostic conditions corresponding to high-load desorption pipelines and diagnostic conditions corresponding to low-load desorption pipelines.

[0072] Specifically, the state of the desorption system may meet either the diagnostic criteria for a high-load desorption pipeline or a low-load desorption pipeline, or it may not meet either diagnostic criteria. Therefore, it is necessary to determine whether the current state of the desorption system meets either diagnostic criterion.

[0073] Furthermore, the specific diagnostic criteria include the following two:

[0074] The diagnostic conditions corresponding to the high-load desorption pipeline include: no faults in the charcoal canister solenoid valve and fuel tank pressure sensor; turbocharger boost pressure and intake manifold pressure are both higher than the corresponding limits; and engine load change and throttle opening change are both lower than the corresponding limits.

[0075] The diagnostic conditions for low-load desorption pipelines include: no faults in the charcoal canister solenoid valve and fuel tank pressure sensor; intake manifold pressure within the set range; and engine load variation and throttle opening variation both below the corresponding limits.

[0076] Specifically, regardless of whether it is a high-load or low-load desorption pipeline, it is necessary to ensure that the charcoal canister solenoid valve and the oil tank pressure sensor are in normal condition. This is because the diagnostic process requires the charcoal canister solenoid valve to switch between open and closed states (switching according to actual working needs, not according to diagnostic requirements), and the oil tank pressure sensor needs to detect changes in oil tank pressure to ensure the validity of the test results.

[0077] At the same time, ensure that the changes in engine load and throttle opening are within normal ranges, that is, ensure that the engine is in normal working condition, so as to ensure that the desorbed gas can enter the engine normally, thereby ensuring that the desorption process can proceed normally.

[0078] Since the main difference between high-load and low-load desorption lines is whether the turbocharger is under boosting conditions, the diagnostic conditions corresponding to high-load and low-load desorption lines can be distinguished based on the turbocharger's boosting conditions and the corresponding intake manifold pressure.

[0079] Step S302: Determine that the desorption system is in desorption mode.

[0080] Specifically, the desorption condition refers to the condition where gas flows from the charcoal canister through the desorption system to the engine. Depending on the engine's operating status and the vehicle's operating status, there may also be situations where no gas enters the engine, such as when the vehicle is parked at an intersection. In this case, the engine is not turned off, but there may be no gas passing through the desorption system.

[0081] During desorption, the solenoid valve of the charcoal canister will be in the open state. That is, when switching from non-desorption to desorption, the solenoid valve of the charcoal canister will switch from the closed state to the open state. Therefore, the duration of the desorption operation can be expressed by the duration of the solenoid valve of the charcoal canister being in the open state.

[0082] Step S303: Determine the current tank pressure and the previous tank pressure.

[0083] Specifically, the tank sensor can acquire the tank pressure in real time during desorption to determine whether the tank pressure is decreasing.

[0084] Step S304: If the tank pressure at the previous moment is higher than the tank pressure at the current moment, determine that the tank pressure is decreasing and increase the timer corresponding to the first duration.

[0085] Specifically, the first duration corresponds to a timer used to record the total duration of the tank pressure decreasing during the desorption process in the current diagnostic procedure, rather than the duration of a single decrease.

[0086] Step S305: The timer duration for which the duration of the desorption condition reaches the desorption condition duration limit is determined as the first duration.

[0087] The desorption operation duration limit is the second duration.

[0088] Specifically, the desorption condition duration limit corresponds to the total duration of the desorption condition in the current diagnostic process. Usually, after the desorption condition duration limit is exceeded, the duty cycle of the carbon canister solenoid valve is prone to change. Therefore, it is necessary to control the duration of the desorption condition in the diagnostic process to avoid the detection of changes in the duty cycle of the carbon canister solenoid valve in subsequent diagnoses, which could lead to diagnostic failure.

[0089] Since the duration limit for the desorption condition is fixed, the first duration within the duration limit may include the duration of multiple complete tank pressure drop processes, or it may include the duration of incomplete tank pressure drop processes, neither of which will affect subsequent calculations.

[0090] Since the duration of the desorption condition is the same as the duration of the solenoid valve of the charcoal canister being in the open state, the duration limit of the desorption condition is equal to the duration of the solenoid valve of the charcoal canister being in the open state, i.e., the second duration. Therefore, the second duration can be directly used to represent the duration limit of the desorption condition for subsequent calculations.

[0091] Step S306: If the desorption system is not in desorption mode, record the duration of non-desorption mode and the real-time oil tank pressure.

[0092] Specifically, under non-desorption conditions, the pressure in the fuel tank is usually near atmospheric pressure (because the charcoal canister vent valve is open, making the fuel evaporation system the same as the atmosphere). The tank pressure will not be negative (because the charcoal canister solenoid valve is normally closed, eliminating a vacuum in the fuel evaporation system). However, if the charcoal canister solenoid valve is stuck open, a vacuum will exist in the fuel evaporation system. In this case, the real-time pressure in the fuel tank will be significantly lower than atmospheric pressure. Therefore, the fuel tank pressure under non-desorption conditions can help determine if a desorption fault exists, and whether the fault is caused by a stuck open or stuck closed charcoal canister solenoid valve (a stuck closed charcoal canister solenoid valve needs to be determined during subsequent desorption conditions based on the fuel tank pressure drop time and its proportion).

[0093] Step S307: Determine the minimum real-time tank pressure when the duration of the non-desorption condition reaches the corresponding duration threshold.

[0094] Specifically, the corresponding time threshold is the time threshold for the tank pressure under non-desorption conditions in the monitoring and diagnosis process. By using the corresponding time threshold, the change in tank pressure (including the maximum and minimum values) within a certain time period can be determined.

[0095] The corresponding time threshold is usually much smaller than the second time, because the corresponding time threshold only needs to ensure that the change in tank pressure within a certain time period can be monitored, and it is not necessary to obtain tank pressure data for too long a period of time.

[0096] In some embodiments, if the desorption system enters the desorption state before the non-desorption period reaches the corresponding time threshold, the minimum real-time tank pressure from the start of the diagnostic process to the entry into the desorption state is obtained.

[0097] Steps S306 to S307 are optional steps parallel to steps S302 to S305. When any condition in step S306 or step S302 is met, the corresponding optional step can be executed. And when step S307 is completed, if the condition in step S302 is met, the execution can be switched to step S302 and its corresponding subsequent steps.

[0098] Step S308: When the total duration of the desorption condition reaches the second duration, the control duty cycle of the carbon canister solenoid valve is constant.

[0099] Specifically, as the control duty cycle of the charcoal canister solenoid valve changes, the downward trend of the oil tank pressure also changes, which makes subsequent calculations more complex and makes it impossible to guarantee the accuracy of the calculations.

[0100] Therefore, it is necessary to determine the control duty cycle of the carbon canister solenoid valve to be a fixed value during the second time period, so as to determine the working state of the desorption system by comparing the ratio of the first time period to the second time period and the relationship of the control duty cycle.

[0101] Step S309: Use the ratio of the first duration to the second duration as the percentage of pressure drop time.

[0102] Specifically, since the pressure drop in the tank lags behind the opening of the charcoal canister solenoid valve, the first time corresponding to the pressure drop and the total time the charcoal canister solenoid valve is open within the second time period are likely not equal (for example, if the charcoal canister solenoid valve has already opened by the second time period, but the tank pressure has not yet dropped, the first time period will be less than the total time the charcoal canister solenoid valve is open). Therefore, it is not possible to directly compare the first time period with the total time the charcoal canister solenoid valve is open. Instead, the ratio of the first time period to the second time period is used to obtain the pressure drop time percentage, which is then compared with the duty cycle of the charcoal canister solenoid valve to avoid errors caused by comparing the first time period with the total time the charcoal canister solenoid valve is open.

[0103] Step S310: Determine the working state of the desorption system based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle and the set threshold.

[0104] Specifically, the exact value may vary depending on the actual operating conditions of the desorption system in different vehicles, based on the second time interval captured. The proportion of pressure drop time and the control duty cycle may differ; that is, the proportion of pressure drop time may be less than or greater than the control duty cycle of the charcoal canister solenoid valve. Therefore, the absolute value of the difference is taken to compare the relationship between the pressure drop time and the total opening time of the charcoal canister solenoid valve. If this absolute value is greater than a set threshold, it usually indicates an abnormal operating condition in the desorption system, requiring further assessment.

[0105] like Figure 3b The diagram shown is a flowchart of a method for determining the operating state of a desorption system based on a set threshold, which includes the following steps:

[0106] Step S3101: If the absolute value of the difference is less than the set threshold, it is determined that the desorption system is in normal working condition.

[0107] Specifically, if the absolute value is less than the set threshold, it means that the proportion of the pressure drop time is roughly the same as the control duty cycle of the charcoal canister solenoid valve, which is in line with the expected state. Therefore, it can be determined that the desorption system is in normal working condition.

[0108] Step S3102: If the absolute value of the difference is greater than or equal to the set threshold, it is determined that there is an abnormal operating condition in the desorption system.

[0109] Specifically, if the absolute value exceeds the set threshold, it indicates a deviation between the proportion of pressure drop time and the control duty cycle of the charcoal canister solenoid valve. This could be due to the pressure drop time being much shorter than the total opening time of the charcoal canister solenoid valve, possibly caused by the solenoid valve being stuck and normally closed; or it could be due to the pressure drop time being much longer than the total opening time of the charcoal canister solenoid valve, possibly caused by the solenoid valve being stuck and normally open. Therefore, further investigation is needed.

[0110] Step S3103: Based on the diagnostic condition type, the real-time minimum oil tank pressure and the set pressure threshold, determine the specific type corresponding to the abnormal operating condition.

[0111] Specifically, since the diagnostic conditions are met for high-load desorption pipelines and low-load desorption pipelines respectively, the corresponding desorption pipelines with abnormalities also differ when abnormalities exist.

[0112] Specific exception types include the following:

[0113] If the diagnostic condition type is high-load desorption pipeline, the corresponding diagnostic condition is:

[0114] Case 1 (not shown): If the minimum real-time oil tank pressure is higher than the set pressure threshold, the specific type of abnormal working condition is determined to be a high-load desorption flow failure and the carbon canister solenoid valve is stuck and normally closed.

[0115] Case 2 (not shown): If the minimum real-time oil tank pressure is lower than the set pressure threshold, the specific type of abnormal working condition is determined to be a high-load desorption flow failure and the carbon canister solenoid valve is stuck and normally open.

[0116] If the diagnostic condition type is low-load desorption pipeline, the corresponding diagnostic condition is:

[0117] Case 3 (not shown): If the minimum real-time oil tank pressure is higher than the set pressure threshold, the specific type of abnormal working condition is determined to be a low-load desorption flow failure and the carbon canister solenoid valve is stuck and normally closed.

[0118] Case 4 (not shown): If the real-time minimum oil tank pressure is lower than the set pressure threshold, the specific type of abnormal working condition is determined to be a low load desorption flow failure and the carbon canister solenoid valve is stuck and normally open.

[0119] Specifically, the relationship between the real-time minimum oil tank pressure and the fault type of the charcoal canister solenoid valve can be found in the aforementioned analysis. The type of abnormal operating condition requires differentiation of which part of the desorption pipeline is abnormal and the corresponding flow rate, as well as the specific fault type of the charcoal canister solenoid valve, in order to facilitate targeted recording and handling later.

[0120] Step S311: When the total duration of the desorption condition reaches the second duration, the control duty cycle of the carbon canister solenoid valve is a non-constant value.

[0121] Specifically, if the control duty cycle of the charcoal canister solenoid valve changes during the second time period, such as when the vehicle's driving state changes significantly (e.g., from forward and deceleration to reverse), the duration of each opening of the charcoal canister solenoid valve will not be fixed, and the duration of the corresponding decrease in the oil tank pressure will also change. In this case, it is impossible to effectively determine the operating condition of the desorption system.

[0122] Step S312: Exit the desorption system working status diagnosis process until the diagnosis conditions are met again.

[0123] Specifically, when the duty cycle of the charcoal canister solenoid valve changes, all data acquired during the entire diagnostic process becomes unusable. Therefore, the diagnostic process must be terminated until the next diagnostic attempt.

[0124] Steps S311 to S312 are optional steps parallel to steps S308 to S310. When the condition of any step in step S308 or step S311 is met, the subsequent optional steps of the corresponding step can be executed.

[0125] The desorption system monitoring method provided in this disclosure determines the specific operating state of the desorption system after confirming that the system meets diagnostic conditions. This is achieved by considering whether the system is in desorption mode, the minimum tank pressure in non-desorption mode, the difference between the tank pressure drop time percentage in desorption mode and the duty cycle of the charcoal canister solenoid valve, and the corresponding threshold. Furthermore, it identifies the specific type of abnormal operating condition when one exists. Therefore, it enables diagnosis of different desorption pipelines based on the actual operating conditions of the desorption system without affecting the normal operation of the charcoal canister solenoid valve. This method is independent of other diagnostic processes, allowing for rapid identification of faults in the desorption system and effective determination of the specific type of abnormal operating condition, significantly improving the safety of the desorption system.

[0126] Figure 4 This is a schematic diagram of a desorption system monitoring device provided in this disclosure. Figure 4 As shown, the desorption system monitoring device 400 includes: a diagnostic module 410, a calculation module 420, and a determination module 430.

[0127] in:

[0128] Diagnostic module 410 is used to determine whether the desorption system meets the diagnostic conditions. The desorption system includes a high-load desorption pipeline and a low-load desorption pipeline. The diagnostic conditions include the diagnostic conditions corresponding to the high-load desorption pipeline and the diagnostic conditions corresponding to the low-load desorption pipeline.

[0129] The calculation module 420 is used to determine the first duration of the tank pressure drop when the desorption system is in desorption mode;

[0130] The determination module 430 is used to determine the working state of the desorption system based on the first duration, the second duration during which the charcoal canister solenoid valve is in the open state, and the control duty cycle of the charcoal canister solenoid valve.

[0131] Optionally, the diagnostic module 410 specifically includes diagnostic conditions corresponding to the high-load desorption pipeline, including: the charcoal canister solenoid valve and fuel tank pressure sensor are not faulty; the turbocharger boost pressure and intake manifold pressure are both higher than the corresponding limits; the engine load change and throttle opening change are both lower than the corresponding limits; and diagnostic conditions corresponding to the low-load desorption pipeline, including: the charcoal canister solenoid valve and fuel tank pressure sensor are not faulty; the intake manifold pressure is within the set range; and the engine load change and throttle opening change are both lower than the corresponding limits.

[0132] Optionally, the calculation module 420 is specifically used to: determine that the desorption system is in desorption mode; determine the tank pressure at the current moment and the tank pressure at the previous moment; if the tank pressure at the previous moment is higher than the tank pressure at the current moment, determine that the tank pressure is in a decreasing state, and increase the timer corresponding to the first duration; determine the timer duration when the duration of the desorption mode reaches the desorption mode duration limit as the first duration, and the desorption mode duration limit is the second duration.

[0133] Optionally, the determining module 430 is specifically used to determine that when the total duration of the desorption condition reaches the second duration, the control duty cycle of the charcoal canister solenoid valve is a constant value; to use the ratio of the first duration to the second duration as the pressure drop time percentage; and to determine the working state of the desorption system based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle of the charcoal canister solenoid valve and a set threshold.

[0134] Optionally, the determining module 430 is also used to, after determining that the desorption system meets the diagnostic conditions, if the desorption system is not in the desorption condition, record the duration of the non-desorption condition and the real-time tank pressure; and determine the minimum real-time tank pressure when the duration of the non-desorption condition reaches the corresponding duration threshold.

[0135] Optionally, the determination module 430 is specifically used to: determine that the desorption system is in normal working condition if the absolute value of the difference is less than a set threshold; determine that the desorption system has an abnormal working condition if the absolute value of the difference is greater than or equal to the set threshold; and determine the specific type of the abnormal working condition based on the diagnostic condition type, the real-time minimum oil tank pressure and the set pressure threshold.

[0136] Optionally, module 430 is specifically used to determine the specific type of abnormal condition as follows: if the diagnostic condition type is high-load desorption pipeline, and the real-time minimum oil tank pressure is higher than the set pressure threshold, then the abnormal condition type is determined to be high-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally closed; if the real-time minimum oil tank pressure is lower than the set pressure threshold, then the abnormal condition type is determined to be high-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally open. If the diagnostic condition type is low-load desorption pipeline, and the abnormal condition type is determined to be low-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally closed; if the real-time minimum oil tank pressure is lower than the set pressure threshold, then the abnormal condition type is low-load desorption flow fault and the charcoal canister solenoid valve is stuck and normally open.

[0137] Optionally, module 430 is specifically used to determine that when the total duration of the desorption condition reaches the second duration, the control duty cycle of the carbon canister solenoid valve is a non-constant value; exit the desorption system working status diagnosis process until the diagnosis conditions are met again.

[0138] In this embodiment, the desorption system monitoring device, through the combination of various modules, can accurately monitor the fuel vapor desorption system by monitoring changes in fuel tank pressure, without requiring additional active control of the charcoal canister solenoid valve or affecting the mixture control. This solves the problem that the desorption system status cannot be accurately monitored inside the fuel tank without affecting driving.

[0139] Figure 5 This is a schematic diagram of the structure of a control device provided in this disclosure, such as... Figure 5 As shown, the control device 500 includes a memory 510 and a processor 520.

[0140] The memory 510 stores a computer program that can be executed by at least one processor 520. This computer program is executed by at least one processor 520 to enable the control device to implement the desorption system monitoring method provided in any of the above embodiments.

[0141] The memory 510 and the processor 520 can be connected via a bus 530.

[0142] The relevant explanations can be understood by referring to the corresponding descriptions and effects in the method embodiments, and will not be repeated here.

[0143] One embodiment of this disclosure provides a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to perform the following: Figures 2 to 3b The desorption system monitoring method of any corresponding embodiment.

[0144] The computer-readable storage medium can be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0145] One embodiment of this disclosure provides a computer program product comprising computer-executable instructions that, when executed by a processor, are used to perform, as follows: Figures 2 to 3b The desorption system monitoring method of any corresponding embodiment.

[0146] In the several embodiments provided in this disclosure, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0147] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0148] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for monitoring a desorption system, characterized in that, The method includes: The desorption system is determined to meet diagnostic conditions, the desorption system includes a high-load desorption pipeline and a low-load desorption pipeline, and the diagnostic conditions include diagnostic conditions corresponding to the high-load desorption pipeline and diagnostic conditions corresponding to the low-load desorption pipeline. If the desorption system is in desorption mode, determine the first duration during which the oil tank pressure is in a decreasing state; By comparing the ratio of the first duration to the second duration during which the charcoal canister solenoid valve is in the open state with the control duty cycle of the charcoal canister solenoid valve, the working state of the desorption system when the charcoal canister solenoid valve is in the open state is determined.

2. The desorption system monitoring method according to claim 1, characterized in that, The diagnostic conditions corresponding to the high-load desorption pipeline include: The charcoal canister solenoid valve and the oil tank pressure sensor were not faulty. Both the turbocharger boost pressure and the intake manifold pressure are higher than the corresponding limits; Both the engine load change and the throttle opening change are below the corresponding limits; The diagnostic conditions corresponding to the low-load desorption pipeline include: The charcoal canister solenoid valve and the oil tank pressure sensor were not faulty. Intake manifold pressure is within the set range; Both the engine load change and the throttle opening change are below the corresponding limits.

3. The desorption system monitoring method according to claim 1, characterized in that, If the desorption system is in desorption mode, the first duration for which the tank pressure is in a decreasing state is determined includes: The desorption system is confirmed to be in desorption mode; Determine the current tank pressure and the previous tank pressure; If the tank pressure at the previous moment is higher than the tank pressure at the current moment, it is determined that the tank pressure is in a decreasing state, and the timer corresponding to the first duration is increased. The timer duration for which the desorption condition duration reaches the desorption condition duration limit is determined as the first duration, and the desorption condition duration limit is the second duration.

4. The desorption system monitoring method according to any one of claims 1 to 3, characterized in that, The process of determining the operating state of the desorption system when the charcoal canister solenoid valve is in the open state by comparing the ratio of the first duration to the second duration during which the charcoal canister solenoid valve is in the open state with the control duty cycle of the charcoal canister solenoid valve includes: When the total duration of the desorption condition reaches the second duration, the control duty cycle of the solenoid valve of the carbon canister is constant. The ratio of the first duration to the second duration is taken as the proportion of pressure drop time; The operating state of the desorption system is determined based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle and a set threshold.

5. The desorption system monitoring method according to claim 4, characterized in that, After determining that the desorption system meets the diagnostic criteria, the method further includes: If the desorption system is not in desorption mode, record the duration of non-desorption mode and the real-time oil tank pressure; Determine the minimum real-time tank pressure when the duration of the non-desorption condition reaches the corresponding duration threshold.

6. The desorption system monitoring method according to claim 5, characterized in that, The determination of the desorption system's operating state based on the absolute value of the difference between the pressure drop time percentage and the control duty cycle, and a set threshold, includes: If the absolute value of the difference is less than the set threshold, it is determined that the desorption system is in normal working condition; If the absolute value of the difference is greater than or equal to the set threshold, it is determined that the desorption system is in an abnormal operating condition. Based on the diagnostic condition type, the real-time minimum oil tank pressure, and the set pressure threshold, the specific type corresponding to the abnormal operating condition is determined.

7. The desorption system monitoring method according to claim 6, characterized in that, The determination of the specific type of abnormal operating condition based on the diagnostic condition type, the real-time minimum oil tank pressure, and the set pressure threshold includes: If the diagnostic condition type is the diagnostic condition corresponding to a high-load desorption pipeline: If the minimum real-time oil tank pressure is higher than the set pressure threshold, the specific type of the abnormal working condition is determined to be a high-load desorption flow fault and the carbon canister solenoid valve is stuck and normally closed. If the minimum real-time oil tank pressure is lower than the set pressure threshold, the specific type of the abnormal working condition is determined to be a high-load desorption flow failure and a stuck, normally open carbon canister solenoid valve. If the diagnostic condition type is the diagnostic condition corresponding to a low-load desorption pipeline: If the minimum real-time oil tank pressure is higher than the set pressure threshold, the specific type of the abnormal working condition is determined to be a low load desorption flow failure and the carbon canister solenoid valve is stuck and normally closed. If the minimum real-time oil tank pressure is lower than the set pressure threshold, the specific type of the abnormal operating condition is determined to be a low-load desorption flow failure and a stuck, normally open carbon canister solenoid valve.

8. The method for monitoring a desorption system according to any one of claims 1 to 3, characterized in that, The process of determining the operating state of the desorption system when the charcoal canister solenoid valve is in the open state by comparing the ratio of the first duration to the second duration during which the charcoal canister solenoid valve is in the open state with the control duty cycle of the charcoal canister solenoid valve includes: When the total duration of the desorption condition reaches the second duration, the control duty cycle of the solenoid valve of the carbon canister is a non-constant value. Exit the desorption system's operational status diagnostic process until the diagnostic conditions are met again.

9. A desorption system monitoring device, characterized in that, include: A diagnostic module is used to determine whether the desorption system meets diagnostic conditions. The desorption system includes a high-load desorption pipeline and a low-load desorption pipeline. The diagnostic conditions include diagnostic conditions corresponding to the high-load desorption pipeline and diagnostic conditions corresponding to the low-load desorption pipeline. The calculation module is used to determine the first duration of the tank pressure being in a decreasing state when the desorption system is in desorption mode; The determination module is used to determine the working state of the desorption system when the charcoal canister solenoid valve is in the open state by comparing the ratio of the first duration to the second duration when the charcoal canister solenoid valve is in the open state with the control duty cycle of the charcoal canister solenoid valve.

10. A control device, characterized in that, include: At least one processor; and a memory communicatively connected to the at least one processor; The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, cause the control device to perform the desorption system monitoring method as described in any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the desorption system monitoring method as described in any one of claims 1 to 8.

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