Fuel tank sloshing recognition method, device, equipment and storage medium

Abstract

This disclosure provides a method, apparatus, device, and storage medium for identifying fuel tank sloshing. The method includes: determining the degree of sloshing of the vehicle as a whole along corresponding directions based on set indicators, whereby the corresponding directions include the direction perpendicular to the chassis, the direction of travel, and the lateral direction of travel; and determining the maximum value of the sloshing degree of the vehicle in each corresponding direction as the degree of sloshing of the fuel tank. This disclosure solves the problem in the prior art where fluctuations in fuel vapor pressure within the fuel tank affect the accuracy of leak detection. It enables rapid determination of whether the fuel tank is in a sloshing state through different set indicators, allowing for timely correction or cessation of the leak diagnosis process, thereby ensuring the accuracy and reliability of leak detection results and greatly expanding the application scenarios of the engine intake manifold vacuum method.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of vehicles, and particularly relates to a fuel tank shaking identification method and device, equipment and storage medium. BACKGROUND

[0002] The vehicle equipped with a gasoline engine is full of a large amount of fuel vapor in the fuel tank due to the volatile nature of gasoline. When the engine is running, the fuel vapor generally passes through the fuel evaporation system composed of the fuel tank, the carbon canister (the carbon canister contains a carbon canister vent valve or equivalent device, such as a gas pump, etc.), the carbon canister electromagnetic valve and a plurality of pipelines in sequence, and is introduced into the engine intake manifold, and then enters the engine cylinder along with the intake flow for combustion, which not only improves the fuel economy of the vehicle, but also prevents a large amount of fuel vapor from leaking into the atmosphere to pollute the environment. In order to prevent fuel vapor leakage, real-time detection of fuel vapor leakage in the fuel evaporation system is also needed to facilitate timely maintenance.

[0003] The most commonly used method for detecting fuel vapor leakage in the prior art is the engine intake manifold vacuum method, which needs to reduce the pressure in the fuel tank to negative pressure by drawing air through the engine intake manifold during vehicle driving, and then identify the leakage condition according to the pressure change state of the pipeline between the fuel tank and the carbon canister, and between the carbon canister and the carbon canister electromagnetic valve.

[0004] However, if the vehicle is on an uphill or downhill, accelerating or decelerating, turning or bumpy road section, the fuel tank will shake, causing the fuel vapor pressure in the fuel tank to fluctuate, and thus the leakage condition cannot be accurately identified from the pressure change state. SUMMARY

[0005] The present disclosure provides a fuel tank shaking identification method, device, equipment and storage medium to solve the influence of fuel vapor pressure fluctuation in the fuel tank on identification accuracy.

[0006] In a first aspect, the present disclosure provides a fuel tank shaking identification method, which comprises:

[0007] Based on the set index, the shaking degree of the vehicle as a whole in the corresponding direction is determined, and the corresponding direction includes a direction perpendicular to the chassis, a direction along the driving direction and a transverse direction of the driving direction.

[0008] The maximum value of the shaking degree of the vehicle in each corresponding direction is determined as the shaking degree of the fuel tank.

[0009] Optionally, the degree of shaking of the vehicle in the corresponding direction is determined based on the set indicators, including: determining the degree of shaking of the vehicle in the direction perpendicular to the chassis based on the acceleration of the wheels and / or the acceleration of the vehicle in the vertical direction; determining the degree of shaking of the vehicle in the driving direction based on the throttle opening, the accelerator opening, the brake master cylinder pressure and / or the acceleration in the driving direction; and determining the degree of shaking of the vehicle in the lateral direction of the driving direction based on the steering wheel angle and / or the acceleration in the lateral direction of the driving direction.

[0010] Optionally, the degree of shaking of the vehicle in the direction perpendicular to the chassis is determined based on the acceleration of the wheels and / or the acceleration of the vehicle as a whole, including: if the maximum value in the absolute value of the wheel acceleration and / or the acceleration of the vehicle in the direction perpendicular to the chassis is greater than or equal to the lower threshold value of the indicator and less than or equal to the upper threshold value of the corresponding indicator, determining that the degree of shaking of the vehicle is slight shaking; and if the maximum value in the absolute value of the wheel acceleration and / or the acceleration of the vehicle in the direction perpendicular to the chassis is greater than the upper threshold value of the corresponding indicator, determining that the degree of shaking of the vehicle is severe shaking.

[0011] Optionally, the degree of shaking of the vehicle in the driving direction is determined based on the throttle opening, the accelerator opening, the brake master cylinder pressure and / or the acceleration in the driving direction, including: if the rate of change of the throttle opening, the rate of change of the accelerator opening, the rate of change of the brake master cylinder pressure and / or the acceleration of the vehicle in the driving direction is greater than or equal to the lower threshold value of the corresponding indicator and less than or equal to the upper threshold value of the corresponding indicator, determining that the degree of shaking of the vehicle is slight shaking; and if the rate of change of the throttle opening, the rate of change of the accelerator opening, the rate of change of the brake master cylinder pressure and / or the acceleration of the vehicle in the driving direction is greater than the upper threshold value of the corresponding indicator, determining that the degree of shaking of the vehicle is severe shaking.

[0012] Optionally, the degree of shaking of the vehicle in the lateral direction of the driving direction is determined based on the steering wheel angle and / or the acceleration in the lateral direction of the driving direction, including: if the rate of change of the steering wheel angle and / or the acceleration of the vehicle in the lateral direction of the driving direction is greater than or equal to the lower threshold value of the indicator and less than or equal to the upper threshold value of the corresponding indicator, determining that the degree of shaking of the vehicle is slight shaking; and if the rate of change of the steering wheel angle and / or the acceleration of the vehicle in the lateral direction of the driving direction is greater than the upper threshold value of the corresponding indicator, determining that the degree of shaking of the vehicle is severe shaking.

[0013] Optionally, before determining the shaking degree of the vehicle as a whole in the corresponding direction based on the set index, the method further comprises: determining that the carbon canister electromagnetic valve is in an open state and the carbon canister breather valve is in a closed state; adding one to the number of times of the oil tank vacuum establishment process, the oil tank vacuum establishment process being used to represent a change of the vacuum degree in the oil tank from a start to a first target vacuum degree, the change of the vacuum degree in the oil tank starting from when the carbon canister electromagnetic valve is opened and the carbon canister breather valve is closed; and accordingly, determining the maximum value of the shaking degree of the vehicle in each corresponding direction as the shaking degree of the oil tank, the method further comprises: if the shaking degree of the oil tank is severe shaking, stopping the leakage diagnosis process; and if the shaking degree of the oil tank is slight shaking, determining the degree of progress of the leakage diagnosis process based on the length of time during which the oil tank is in slight shaking and the oil tank pressure.

[0014] Optionally, the determining the degree of progress of the leakage diagnosis process based on the length of time during which the oil tank is in slight shaking and the oil tank pressure comprises: determining a ratio of the length of time during which the oil tank is in slight shaking to the total length of time of the oil tank vacuum establishment process when the vacuum degree in the oil tank reaches the first target vacuum degree; if the ratio is less than a set ratio threshold, determining that the leakage diagnosis process enters a micro-leakage diagnosis process; if the ratio is greater than or equal to the set ratio threshold, determining a derivative of the oil tank pressure change rate in a set time period after the vacuum degree in the oil tank reaches the first target vacuum degree; if the derivative exceeds a set derivative threshold, stopping the leakage diagnosis process; and if the derivative does not exceed the set derivative threshold, determining that the oil tank pressure reaches a second target vacuum degree and entering the micro-leakage diagnosis process.

[0015] Optionally, the carbon canister electromagnetic valve is switched to a closed state and the carbon canister breather valve is kept in the closed state when the vacuum degree in the oil tank reaches the first target vacuum degree, and after the derivative of the oil tank pressure change rate in the set time period after the vacuum degree in the oil tank reaches the first target vacuum degree is determined, the method further comprises: if the derivative does not exceed the set derivative threshold and the oil tank pressure does not reach the second target vacuum degree, determining that the carbon canister electromagnetic valve is in a re-opened state and adding one to the number of times of the oil tank vacuum establishment process; and if the number of times of the oil tank vacuum establishment process exceeds a set number of times, stopping the leakage diagnosis process.

[0016] Optionally, before determining the shaking degree of the vehicle as a whole in the corresponding direction based on the set index, the method further comprises: determining that the carbon canister electromagnetic valve and the carbon canister breather valve are both in a closed state; and accordingly, determining the maximum value of the shaking degree of the vehicle in each corresponding direction as the shaking degree of the oil tank, the method further comprises: if the shaking degree of the oil tank is severe shaking, stopping the leakage diagnosis process.

[0017] In a second aspect, the present disclosure provides an oil tank shaking recognition device, comprising:

[0018] The detection module is used to determine the degree of sway of the vehicle as a whole in the corresponding direction based on the set indicators. The corresponding direction includes the direction perpendicular to the chassis, along the driving direction, and the lateral direction of the driving direction.

[0019] The determination module is used to determine the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank.

[0020] Optionally, the detection module is specifically used to: determine the degree of vehicle sway in the direction perpendicular to the chassis based on the acceleration of the wheels and / or the acceleration of the vehicle in the vertical direction; determine the degree of vehicle sway in the direction of travel based on the throttle opening, accelerator opening, brake master cylinder pressure and / or acceleration in the direction of travel; and determine the degree of vehicle lateral sway in the direction of travel based on the steering wheel angle and / or lateral acceleration in the direction of travel.

[0021] Optionally, the detection module is specifically used to determine the vehicle sway as slight if the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than or equal to the lower threshold of the indicator and less than or equal to the upper threshold of the corresponding indicator; and to determine the vehicle sway as severe if the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than the upper threshold of the corresponding indicator.

[0022] Optionally, the detection module is specifically used to determine the degree of vehicle shaking as slight shaking if the rate of change of vehicle throttle opening, the rate of change of accelerator opening, the rate of change of brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the driving direction is greater than or equal to the lower threshold of the corresponding indicator, and less than or equal to the upper threshold of the corresponding indicator; and to determine the degree of vehicle shaking as severe shaking if the rate of change of vehicle throttle opening, the rate of change of accelerator opening, the rate of change of brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the driving direction is greater than the upper threshold of the corresponding indicator.

[0023] Optionally, the detection module is specifically used to determine the degree of vehicle shaking as slight shaking if the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the driving direction is greater than or equal to the lower threshold of the corresponding indicator and less than or equal to the upper threshold of the corresponding indicator; and to determine the degree of vehicle shaking as severe shaking if the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the driving direction is greater than the upper threshold of the corresponding indicator.

[0024] Optionally, the detection module is further configured to, before determining the degree of vehicle swaying along the corresponding direction based on set indicators, determine that the vehicle's charcoal canister solenoid valve is in the open state and the charcoal canister vent valve is in the closed state; increment the number of times the fuel tank vacuum is established, whereby the fuel tank vacuum is defined as the change in the fuel tank vacuum from the start to reaching the first target vacuum, and the change in the fuel tank vacuum begins when the charcoal canister solenoid valve is open and the charcoal canister vent valve is closed; correspondingly, the determination module is further configured to, after determining the maximum value of the vehicle's swaying in each corresponding direction as the degree of fuel tank swaying, if the degree of fuel tank swaying is severe, stop the leak diagnosis process; if the degree of fuel tank swaying is slight, determine the extent of the leak diagnosis process based on the duration of slight swaying and the fuel tank pressure.

[0025] Optionally, the determining module is specifically used to determine the ratio of the time the tank is slightly shaking when the vacuum level in the tank reaches the first target vacuum level to the total time of the process of establishing the vacuum level in the tank; if the ratio is less than a set ratio threshold, the leak diagnosis process is determined to enter the micro-leakage diagnosis process; if the ratio is greater than or equal to the set ratio threshold, the derivative of the rate of change of the tank pressure within a set time period after the vacuum level in the tank reaches the first target vacuum level is determined; if the derivative exceeds a set derivative threshold, the leak diagnosis process is stopped; if the derivative does not exceed the set derivative threshold, the tank pressure is determined to have reached the second target vacuum level, and the micro-leakage diagnosis process is entered.

[0026] Optionally, the determining module is also used to: if the vacuum level in the tank reaches the first target vacuum level, switch the charcoal canister solenoid valve to the closed state and keep the charcoal canister vent valve in the closed state; after determining the derivative of the rate of change of tank pressure within a set time period after the vacuum level in the tank reaches the first target vacuum level, if the derivative does not exceed the set derivative threshold and the tank pressure does not reach the second target vacuum level, determine that the charcoal canister solenoid valve is in the reopened state and increment the number of times the tank establishes vacuum level; if the number of times the tank establishes vacuum level exceeds the set number, stop the leak diagnosis process.

[0027] Optionally, the detection module is also used to determine that both the charcoal canister solenoid valve and the charcoal canister vent valve are in the closed state before determining the degree of shaking of the vehicle as a whole in the corresponding direction based on the set indicators; correspondingly, the determination module is also used to determine the maximum value of the shaking degree of the vehicle in each corresponding direction as the degree of shaking of the fuel tank, and if the degree of shaking of the fuel tank is severe, then stop the leak diagnosis process.

[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 fuel tank sway recognition 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 the fuel tank sway recognition method as described in any of the first aspects of this disclosure.

[0033] The fuel tank sloshing identification method, device, equipment, and storage medium disclosed herein determine the degree of sloshing of the entire vehicle along corresponding directions based on set indicators. Then, the maximum value of the sloshing degree of the vehicle in each corresponding direction is determined as the degree of sloshing of the fuel tank. Thus, by using different set indicators, it is possible to quickly determine whether the fuel tank is in a sloshing state, thereby promptly correcting or stopping the leak diagnosis process, ensuring the accuracy and reliability of leak detection results, and greatly expanding the application scenarios of the engine intake manifold vacuum method. 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 fuel tank sway recognition method provided in the embodiments of this disclosure;

[0036] Figure 2 A flowchart of a fuel tank sway recognition method provided in one embodiment of this disclosure;

[0037] Figure 3a A flowchart of a fuel tank sway recognition method provided in yet another embodiment of this disclosure;

[0038] Figure 3b for Figure 3a The flowchart of the leakage diagnosis process judgment method provided in the embodiment shown;

[0039] Figure 4 A flowchart of a fuel tank sway recognition method provided in yet another embodiment of this disclosure;

[0040] Figure 5 A schematic diagram of the structure of a fuel tank sway recognition device provided in yet another embodiment of this disclosure;

[0041] Figure 6 This is a schematic diagram of the structure of a control device provided in yet another embodiment of this disclosure.

[0042] 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

[0043] 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.

[0044] The following is a description of the terminology used in this disclosure:

[0045] 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.

[0046] Engine intake manifold vacuum method: This method is used to monitor for leaks in the fuel evaporation system. By opening the charcoal canister solenoid valve and closing the charcoal canister vent valve, a negative pressure is created in the fuel tank through the engine intake manifold. If the pressure in the fuel tank does not reach a certain level of negative pressure, a large leak is identified, such as a detached pipe or a loose fuel tank cap. If a certain level of negative pressure is reached, a 1mm leak is detected. The charcoal canister solenoid valve is then closed again, creating a sealed chamber in the fuel evaporation system. The pressure in the fuel tank should rise slowly due to gasoline evaporation, with a relatively small rate of increase. If a leak of more than 1mm is present, atmospheric air enters the fuel tank rapidly, causing a faster and larger pressure rise. Therefore, different leak sizes correspond to different pressure rise rates, which are used to identify the amount of leakage in the fuel evaporation system.

[0047] 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.

[0048] Vehicles equipped with gasoline engines experience significant fuel vapor buildup in their fuel evaporation systems due to the volatility of gasoline. To prevent fuel vapor leakage, real-time monitoring of this system is crucial for timely repairs. Current methods for detecting fuel vapor leaks primarily rely on the engine intake manifold vacuum method. This method determines the leakage amount based on the rate of change in air pressure within the fuel evaporation system during the monitoring period. However, since pressure is closely related to the size of the space, vehicle movement on inclines, declines, turns, or bumpy roads can cause fuel tank swaying. This continuous change in the space connected to the fuel tank pressure sensor leads to fluctuations in fuel vapor pressure within the tank, making the measurement results inaccurately reflect the actual pressure inside the tank and thus failing to accurately identify leaks based on pressure variations.

[0049] To address the aforementioned issues, this disclosure provides a fuel tank sway identification method. Based on set indicators, the method quickly determines the degree of fuel tank sway in a vehicle. Consequently, it can determine whether to correct the fuel tank leak diagnosis process based on the fuel tank sway situation, effectively resolving the impact of fuel vapor pressure fluctuations within the fuel tank on identification accuracy.

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

[0051] Figure 1 This diagram illustrates an application scenario of the oil tank vent shut-off valve liquid seal 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 in the fuel tank or at the connection between the fuel tank and the charcoal canister. The charcoal canister solenoid valve 104 is connected to the intake manifold 111 of the engine 110. During the fuel evaporation system leak detection process, by closing the charcoal canister vent valve 103 and opening the charcoal canister solenoid valve 104, the intake manifold 111 draws out the oil vapor in the fuel evaporation system 100. The pressure sensor 106 can determine whether a leak has occurred based on the detected pressure change.

[0052] It should be noted that, Figure 1 The scenario shown uses only one pressure sensor as an example for illustration, but this disclosure is not limited to this; that is, the number of pressure sensors can be arbitrary.

[0053] The fuel tank sway recognition method provided in this disclosure is described in detail below through 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.

[0054] Figure 2 This is a flowchart illustrating a fuel tank sway recognition method provided in one embodiment of this disclosure. Figure 2 As shown, it includes the following steps:

[0055] Step S201: Based on the set indicators, determine the degree of swaying of the vehicle as a whole in the corresponding direction.

[0056] The corresponding directions include those perpendicular to the chassis direction, along the driving direction, and laterally along the driving direction.

[0057] Specifically, leak detection of the fuel evaporation system is generally carried out while the car is in motion or the engine is running. At this time, the engine can work to draw in oil vapor from the fuel evaporation system through the engine intake manifold, and then the leak can be detected by the engine intake manifold vacuum method.

[0058] Leak detection, before vacuuming, may also include checking whether the charcoal canister solenoid valve and charcoal canister vent valve are functioning properly. This ensures that the fuel evaporation system can operate normally during vacuuming, thereby guaranteeing the reliability of the detection results.

[0059] The fuel evaporation system is in a leak detection and vacuuming state. This can also be achieved when the processor or server receives a signal that the charcoal canister solenoid valve is open and the charcoal canister vent valve is closed. At this time, the pressure sensor will detect changes in the pressure gradient (or it can receive a signal from the pressure sensor that the pressure has started to drop, indicating that vacuuming has begun).

[0060] The fuel evaporation system ends the leak detection and vacuuming state, that is, the processor or server receives a signal that the charcoal canister solenoid valve is closed (at this time the charcoal canister vent valve is still closed).

[0061] From the moment the fuel evaporation system enters the leak detection vacuuming state until it exits, the air pressure inside the fuel evaporation system continuously decreases due to the engine intake manifold evacuating the system. If there is a leak in the fuel evaporation system at this time, the change in air pressure will differ from the change in air pressure when there is no leak. Therefore, it is possible to determine whether there is a leak in the fuel evaporation system.

[0062] However, if the fuel tank is shaking at this time, it will lead to inaccurate detection of changes in air pressure.

[0063] Similarly, after the fuel evaporation system finishes the vacuuming process, the pressure changes within the fuel evaporation system can be used to determine if there is a leak. However, if the fuel tank is shaking at this time, it will also lead to inaccurate detection of air pressure changes, which in turn will result in inaccurate leak detection results.

[0064] Therefore, it is necessary to check whether there is any shaking in the fuel tank during these two stages.

[0065] Since the shaking of the fuel tank is usually caused by the shaking of the entire vehicle, the shaking of the fuel tank can be determined by judging the shaking of the entire vehicle.

[0066] The swaying process of the fuel tank is usually a relatively complex motion process, such as frequent changes in position in multiple directions at the same time. Therefore, the swaying process of the fuel tank can be substituted into a three-dimensional coordinate system centered on the vehicle, and the overall swaying of the vehicle can be determined based on the swaying along each coordinate axis.

[0067] The specific coordinate axis direction can be selected as perpendicular to the chassis direction (that is, the vertical direction or z-axis direction in the coordinate axis), along the driving direction (that is, the parallel direction or y-axis direction in the coordinate axis), and laterally along the driving direction (that is, the vertical direction or x-axis direction in the coordinate axis). By determining the vehicle swaying in these three directions respectively, the overall vehicle swaying can be obtained.

[0068] To determine the vehicle's swaying in each direction, different indicators can be selected. For example, perpendicular to the chassis direction, the vertical acceleration detected by the vehicle's overall acceleration sensor can be used. The swaying in that direction can be determined based on the change in velocity along the vertical direction, because a large acceleration in this direction indicates that the vehicle is in an environment of up-and-down bumps. Similarly, for the lateral direction of travel, the rate of change of the steering wheel rotation speed can be used to determine whether the vehicle is swaying in that direction, because when the steering wheel is turned suddenly and quickly, the vehicle will accelerate laterally, which usually results in lateral swaying.

[0069] Step S202: Determine the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank.

[0070] Specifically, since any shaking in any direction corresponds to shaking of the fuel tank, when the degree of shaking in any direction reaches the preset level of violent shaking, it can be considered that the degree of shaking of the fuel tank has reached the standard of violent shaking. At this point, the leak detection process should not continue, because the accuracy of the measurement results cannot be guaranteed.

[0071] Similarly, if the degree of shaking in any direction is low, it can be directly assumed that the degree of shaking in the fuel tank is low. In this case, the leak detection process can continue because the measurement results are less affected by the shaking of the fuel tank, and the accuracy of the measurement results can be guaranteed.

[0072] The fuel tank sway recognition method provided in this disclosure acquires fuel tank pressure sampling data within a set sampling time period. Based on this data, it determines the pressure change within the current sampling time period. If the pressure change meets set conditions, the exponentially weighted moving average of the pressure change rate during the current sampling time period is used as an indicator to determine the fuel tank pressure change state. Therefore, by calculating the pressure change rate over time periods, the computational impact of slight fuel tank sway during driving is reduced, improving the robustness of the pressure rise rate. Furthermore, by employing an exponentially weighted moving average calculation method, the impact of occasional false detections is avoided, increasing the robustness of the monitoring results and significantly expanding the application scenarios of the engine intake manifold vacuum method.

[0073] Figure 3a This is a flowchart of a fuel tank sloshing detection method provided in this disclosure. Figure 3a As shown, the fuel tank sway recognition method provided in this embodiment includes the following steps:

[0074] Step S301: Determine that the vehicle's charcoal canister solenoid valve is in the open state and the charcoal canister ventilation valve is in the closed state.

[0075] Specifically, during the leak detection process using the engine intake manifold vacuum method, after checking whether the charcoal canister solenoid valve and charcoal canister vent valve are functioning properly (i.e., confirming that the charcoal canister solenoid valve and charcoal canister vent valve are functioning properly), the charcoal canister solenoid valve can be opened and the charcoal canister vent valve closed. This allows air from the fuel evaporation system to flow into the engine through the engine intake manifold, while no new air enters the fuel evaporation system. This causes the fuel tank pressure to gradually decrease, thereby achieving a vacuum effect, which is the process of establishing a vacuum.

[0076] If the fuel tank pressure can drop to the target pressure (which is calculated from the first target vacuum level), it indicates that there are no obvious leaks in the fuel evaporation system (otherwise, a large amount of gas would enter the fuel evaporation system, preventing the fuel tank pressure from dropping to the target pressure). The next stage of testing can then proceed.

[0077] In some embodiments, the tank pressure and target pressure referred to in this disclosure actually refer to atmospheric pressure, air pressure or gas pressure, rather than the pressure value obtained by multiplying pressure and area (because the field of gas and vacuum generally does not discuss specific pressure, but only pressure).

[0078] Step S302: Increment the number of times the oil tank vacuum is established.

[0079] The process of establishing vacuum in the fuel tank is used to represent the change in vacuum level in the fuel tank from the beginning to the arrival of the first target vacuum level. The change in vacuum level in the fuel tank begins when the canister solenoid valve is opened and the canister ventilation valve is closed.

[0080] Specifically, if the fuel tank shakes violently, the judgment on whether there is a leak during the vacuum establishment process may not be accurate enough, or it may be impossible to determine in time whether the fuel tank pressure has dropped to the target pressure. Therefore, it may be necessary to repeat the vacuum establishment process. However, if the process is repeated too many times, the fuel tank may shake frequently. In this case, the measurement results cannot be used for subsequent judgment, and the test needs to be stopped.

[0081] Therefore, it is necessary to count the number of times the vacuum level is established in the fuel tank.

[0082] In some embodiments, when the vacuum is re-established, the relevant timers (such as timers that calculate the duration of shaking) are reset.

[0083] Step S303: Determine the degree of vehicle sway in the direction perpendicular to the chassis based on the acceleration of the wheels and / or the acceleration of the vehicle in the vertical direction.

[0084] Specifically, after entering the vacuum establishment process, the degree of oil tank shaking will be continuously detected. If the degree of oil tank shaking is detected to be too violent at any time during this process, the subsequent detection process will be stopped directly.

[0085] Furthermore, the specific methods for determining the degree of vehicle sway in the direction perpendicular to the chassis include:

[0086] If the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than or equal to the lower threshold of the indicator, and less than or equal to the upper threshold of the corresponding indicator, then the degree of vehicle swaying is determined to be slight swaying; if the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than the upper threshold of the corresponding indicator, then the degree of vehicle swaying is determined to be severe swaying.

[0087] Specifically, each wheel of the vehicle is equipped with a wheel speed sensor. When the absolute value of the acceleration of any wheel exceeds the corresponding upper threshold, it usually indicates that a wheel has suddenly started spinning, slipping, lifting off the ground, or hitting a large obstacle. At this time, since part of the vehicle structure has suddenly left the ground, it will inevitably indicate that the fuel tank is shaking perpendicular to the chassis (or shaking perpendicular to the ground). If the absolute value of the acceleration of a single wheel exceeds the lower threshold, it may indicate that the ground contacted by that wheel is different from the ground contacted by other wheels (such as potholes or uneven ground). Therefore, the fuel tank will also shake perpendicular to the chassis.

[0088] If the vehicle's overall acceleration sensors can detect acceleration in different directions, the relationship between the acceleration perpendicular to the chassis and the corresponding upper and lower thresholds can be used to determine whether the fuel tank will have noticeable up-and-down swaying (i.e., swaying perpendicular to the chassis) if the acceleration is greater than the upper threshold. If the acceleration is between the upper and lower thresholds, it can also be determined that the fuel tank will have slight up-and-down swaying.

[0089] Since the fluctuation range of the specific value varies for each set indicator, corresponding upper and lower thresholds can be configured for each indicator.

[0090] Step S304: Determine the degree of vehicle swaying in the direction of travel based on throttle opening, accelerator opening, brake master cylinder pressure and / or acceleration in the direction of travel.

[0091] Specifically, the degree of swaying along the direction of travel can be determined by the vehicle's acceleration along that direction. If the acceleration suddenly becomes very large or very small (or its absolute value suddenly becomes very large), then the degree of swaying along the direction of travel can be considered to be large.

[0092] Furthermore, the specific methods for determining the degree of vehicle sway along the direction of travel include:

[0093] If the rate of change of throttle opening, the rate of change of accelerator opening, the rate of change of brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the direction of travel are greater than or equal to the lower threshold of the corresponding indicators, and less than or equal to the upper threshold of the corresponding indicators, then the degree of vehicle shaking is determined to be slight shaking; if the rate of change of throttle opening, the rate of change of accelerator opening, the rate of change of brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the direction of travel are greater than the upper threshold of the corresponding indicators, then the degree of vehicle shaking is determined to be severe shaking.

[0094] Specifically, the throttle valve is a valve used to control whether air enters the engine to mix with fuel, forming an air-fuel mixture. If the throttle valve opening changes at a large rate, meaning a large amount of air suddenly enters the engine, it can be considered that the vehicle is accelerating violently by pressing the accelerator, resulting in severe shaking along the direction of travel. Similarly, if the throttle valve opening changes at a smaller rate, the degree of vehicle shaking will decrease.

[0095] The throttle opening change rate is a structure that works in conjunction with the vehicle's throttle opening change rate to control the amount of fuel entering the engine and mixing with air to form a fuel-air mixture. Its working principle is similar to that of the vehicle's throttle opening change rate, and will not be elaborated here.

[0096] The master cylinder works in conjunction with the brake pedal in a vehicle to convert the mechanical braking force into hydraulic pressure. If the pressure change rate in the master cylinder is large, it usually indicates that the brakes have been applied suddenly. As a result, the vehicle will decelerate significantly in the direction of travel, leading to violent shaking. Similarly, if the pressure change rate in the master cylinder is small, the vehicle will decelerate less in the direction of travel, and the degree of shaking will be less.

[0097] If the vehicle's overall acceleration sensors can directly acquire the acceleration along the driving direction, they can also directly determine the degree of swaying along the driving direction. The greater the acceleration, the more violent the swaying.

[0098] Step S305: Determine the degree of lateral sway of the vehicle along the driving direction based on the steering wheel angle and / or the lateral acceleration along the driving direction.

[0099] Specifically, lateral swaying along the direction of travel is usually caused by the vehicle turning or yawing to the side. Therefore, the degree of lateral swaying of the vehicle can be judged based on the vehicle's yaw.

[0100] Furthermore, the specific methods for determining the degree of lateral sway of the vehicle along the direction of travel include:

[0101] If the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the direction of travel is greater than or equal to the lower threshold of the corresponding indicator, and less than or equal to the upper threshold of the corresponding indicator, then the degree of vehicle swaying is determined to be slight swaying; if the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the direction of travel is greater than the upper threshold of the corresponding indicator, then the degree of vehicle swaying is determined to be severe swaying.

[0102] Specifically, a larger rate of change in steering wheel angle indicates that the vehicle suddenly turns sharply to the side, which can be considered as a violent lateral sway. Conversely, a smaller rate of change in steering wheel angle indicates that the vehicle suddenly turns less and the degree of lateral sway is also less.

[0103] If the vehicle's acceleration sensor can acquire the lateral acceleration along the direction of travel, it can also directly determine the degree of lateral sway based on the magnitude of the acceleration. The principle is the same as the principle of judging the degree of sway by the vehicle's acceleration in other directions mentioned above, and will not be repeated here.

[0104] Step S306: Determine the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank.

[0105] Specifically, this step is related to Figure 2 Step S202 in the illustrated embodiment is the same and will not be repeated here.

[0106] Step S307: If the shaking of the oil tank is severe, stop the leak diagnosis process.

[0107] Specifically, if the fuel tank is shaking violently, the accuracy of the test and diagnosis results will be extremely low, and the measurement results will not be reliable. Therefore, the leak diagnosis process can be stopped directly until the vehicle has passed through the area that caused the violent shaking, and then the test can be repeated.

[0108] Step S308: If the shaking of the oil tank is slight, the extent of the leak diagnosis process is determined based on the duration of slight shaking and the oil tank pressure.

[0109] Specifically, if the fuel tank shaking is relatively slight, then the shaking will not directly render the diagnostic results unreliable. Therefore, it is necessary to further assess the situation by considering the duration of the slight shaking and the fuel tank pressure.

[0110] like Figure 3b The diagram shown is a flowchart of the leak diagnosis process. The method for determining a leak by analyzing the duration of slight shaking in the tank and the tank pressure includes:

[0111] Step S3081: Determine the ratio of the time the oil tank is slightly shaking when the vacuum level in the oil tank reaches the first target vacuum level to the total time of the process of establishing the vacuum level in the oil tank.

[0112] Specifically, while slight shaking will not directly render the leak diagnosis results inapplicable, if the slight shaking lasts for too long, it will still affect the accuracy of judging whether the pressure inside the fuel tank has reached the target pressure required to complete the vacuum. This is because prolonged slight shaking of the fuel tank will cause more fuel to evaporate, making the pressure in the fuel evaporation system higher than normal. Therefore, it will take longer to judge whether the pressure inside the fuel tank has reached the target pressure. Thus, it is necessary to determine the duration of slight shaking of the fuel tank to determine the accuracy of the currently acquired pressure inside the fuel tank.

[0113] Since different sizes and types of fuel tanks take different amounts of time to build up vacuum, the ratio of the time the fuel tank is in a state of slight shaking to the total time the fuel tank takes to build up vacuum is used to determine whether the fuel tank is in a state of prolonged, continuous slight shaking.

[0114] Step S3082: If the ratio is less than the set ratio threshold, the leak diagnosis process enters the micro-leak diagnosis process.

[0115] Specifically, if the ratio is less than the set threshold ratio, it can be considered that the oil tank is not in a situation of continuous slight shaking for a long time. The slight shaking of the oil tank during the process of establishing vacuum does not affect the accuracy of the obtained oil tank pressure. At this time, the subsequent diagnostic process, namely micro-leakage diagnosis, can be carried out directly.

[0116] Step S3083: If the ratio is greater than or equal to the set ratio threshold, determine the derivative of the rate of change of tank pressure within a set time period after the vacuum level in the tank reaches the first target vacuum level.

[0117] Specifically, if the ratio is greater than or equal to the set ratio threshold, the accuracy of the tank pressure obtained directly is insufficient, and other indicators need to be used to make a judgment.

[0118] The derivative of the rate of change of tank pressure used here describes the trend of change of tank pressure within a set time period after the tank pressure reaches the first target vacuum level. If the derivative is large, it indicates that the tank pressure changes drastically, which usually indicates leakage, violent shaking, or liquid sealing of the pressure sensor. If the derivative is small, it indicates that the tank pressure changes gradually and is in the normal process of establishing vacuum.

[0119] Step S3084: If the derivative exceeds the set derivative threshold, stop the leak diagnosis process.

[0120] Specifically, if the derivative exceeds the set derivative threshold, it indicates that the pressure change in the tank is too gradual. If there was no violent shaking in the previous test, it can be directly considered that there is a leak or liquid seal (as mentioned above). In this case, the leak diagnosis process should be stopped directly.

[0121] Step S3085: If the derivative does not exceed the set derivative threshold, determine that the tank pressure has reached the second target vacuum level, and proceed with the micro-leakage diagnosis process.

[0122] Specifically, if the derivative does not exceed the set derivative, it indicates that the tank pressure change trend is gradual. However, since the tank is in a state of continuous slight shaking, the original target pressure cannot be used (when the detected tank pressure reaches the target pressure, the actual tank pressure after excluding the influence of slight shaking may be higher or lower than the target pressure). Therefore, another threshold needs to be used for measurement, namely the second target vacuum degree. At this time, the tank pressure corresponding to the second target vacuum degree can be higher than the target pressure corresponding to the first target vacuum degree (for example, if the target pressure corresponding to the first target vacuum degree is -20 hpa, then the tank pressure corresponding to the second target vacuum degree can be -17 hpa, so as to ensure that the micro-leakage diagnosis process can proceed normally when the tank pressure is slightly higher than the first target vacuum degree).

[0123] This effectively ensures that the actual tank pressure has reached the target pressure corresponding to the first target vacuum level, thus affecting the accuracy of subsequent testing.

[0124] Step S3086: If the derivative does not exceed the set derivative threshold and the tank pressure has not reached the second target vacuum level, determine that the canister solenoid valve is in the reopened state and increment the number of times the tank vacuum level is established. Specifically, when the vacuum level in the tank reaches the first target vacuum level, the server or controller will switch the canister solenoid valve to the closed state and keep the canister vent valve closed. This is to facilitate subsequent minor leak diagnosis. However, if the derivative does not exceed the set derivative threshold and the tank pressure has not reached the second target vacuum level, it indicates that the tank pressure is still high and shows no downward trend. Therefore, the canister solenoid valve needs to be reopened to continue the vacuum level establishment process.

[0125] However, since this vacuum establishment process takes place after the regular vacuum establishment process has ended (because the detected tank pressure has reached the first target vacuum level, so the regular vacuum establishment process has ended), it is necessary to increment the number of times the tank vacuum establishment process is performed to record the progress of the process.

[0126] Step S3087: If the number of times the vacuum is established in the oil tank exceeds the set number, stop the leak diagnosis process.

[0127] Specifically, since the derivative of the rate of change of oil tank pressure and other values ​​in the aforementioned calculations are within the normal range, under normal circumstances, after the vacuum establishment process of the priority number of times (such as two or three times), the oil tank pressure can usually reach the second target vacuum level. If it cannot be reached, it may be a fault of the pressure sensor itself or a fault of the algorithm system. In this case, the subsequent leak diagnosis process should not be carried out.

[0128] The fuel tank sloshing identification method provided in this disclosure acquires the degree of vehicle sloshing in various directions in real time during the vacuum establishment phase, thereby determining the degree of fuel tank sloshing and deciding whether to continue the subsequent diagnostic process. Furthermore, when slight sloshing occurs, the method combines the fuel tank pressure and the duration of the slight sloshing to determine whether to proceed with the minor leak diagnosis process. This effectively ensures the accuracy of the data acquired during the vacuum establishment phase, thus guaranteeing the accuracy of subsequent leak diagnosis results. This expands the applicability of the engine intake manifold vacuum method, making it suitable not only for stable situations where the fuel tank does not slosh but also for non-stable situations with slight sloshing.

[0129] Figure 4 This is a flowchart of a fuel tank sloshing detection method provided in this disclosure. Figure 4 As shown, the fuel tank sway recognition method provided in this embodiment includes the following steps:

[0130] Step S401: Ensure that both the charcoal canister solenoid valve and the charcoal canister ventilation valve are in the closed state.

[0131] Specifically, when both the charcoal canister solenoid valve and the charcoal canister vent valve are closed, the fuel tank is in the process of diagnosing minor leaks. At this time, it is necessary to determine whether there is a minor leak (such as a leak hole with a diameter of about 1 mm) based on the pressure changes in the fuel evaporation system. It is also necessary to determine whether there is fuel tank shaking, because it is also necessary to monitor the changes in fuel tank pressure. If there is severe shaking in the fuel tank, the accuracy of the results cannot be guaranteed.

[0132] Step S402: Based on the set indicators, determine the degree of swaying of the vehicle as a whole in the corresponding direction.

[0133] The corresponding directions include those perpendicular to the chassis direction, along the driving direction, and laterally along the driving direction.

[0134] Step S403: Determine the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank.

[0135] Specifically, the content of steps S402 to S403 is the same as... Figure 2 Steps S201 to S202 in the illustrated embodiment are the same and will not be repeated here.

[0136] Step S404: If the shaking of the oil tank is severe, stop the leak diagnosis process.

[0137] Specifically, if the fuel tank experiences severe shaking, the results of the minor leak diagnosis will be unusable, and the leak diagnosis process must be stopped.

[0138] If the fuel tank experiences slight shaking or no shaking at all, it will not affect the usability of the test results. Therefore, the subsequent diagnostic process can continue until the diagnosis is completed.

[0139] The fuel tank sloshing identification method provided in this disclosure detects the pressure in all directions of the vehicle in real time during the micro-leak diagnosis process, determines the degree of fuel tank sloshing, and determines whether to continue micro-leak detection and subsequent diagnosis. This effectively ensures the availability of data acquired during micro-leak detection, thereby guaranteeing the reliability of subsequent leak diagnosis results. This expands the applicability of the engine intake manifold vacuum method, making it suitable not only for stable situations where the fuel tank does not slosh but also for non-stable situations with slight sloshing.

[0140] Figure 5 This is a schematic diagram of the structure of a fuel tank sway detection device provided in this disclosure. Figure 5 As shown, the fuel tank sway detection device 500 includes: a detection module 510 and a determination module 520. Wherein:

[0141] The detection module 510 is used to determine the degree of sway of the vehicle as a whole in the corresponding direction based on the set indicators. The corresponding direction includes the direction perpendicular to the chassis, the direction of travel, and the lateral direction of travel.

[0142] The determination module 520 is used to determine the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank.

[0143] Optionally, the detection module 510 is specifically used to: determine the degree of vehicle sway in the direction perpendicular to the chassis based on the acceleration of the wheels and / or the acceleration of the vehicle in the vertical direction; determine the degree of vehicle sway in the direction of travel based on the throttle opening, accelerator opening, brake master cylinder pressure and / or acceleration in the direction of travel; and determine the degree of vehicle lateral sway in the direction of travel based on the steering wheel angle and / or lateral acceleration in the direction of travel.

[0144] Optionally, the detection module 510 is specifically used to determine the degree of vehicle shaking as slight shaking if the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than or equal to the lower threshold of the indicator and less than or equal to the upper threshold of the corresponding indicator; and to determine the degree of vehicle shaking as severe shaking if the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than the upper threshold of the corresponding indicator.

[0145] Optionally, the detection module 510 is specifically used to determine the degree of vehicle shaking as slight shaking if the rate of change of vehicle throttle opening, the rate of change of accelerator opening, the rate of change of brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the driving direction is greater than or equal to the lower threshold of the corresponding index, and less than or equal to the upper threshold of the corresponding index; and to determine the degree of vehicle shaking as severe shaking if the rate of change of vehicle throttle opening, the rate of change of accelerator opening, the rate of change of brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the driving direction is greater than the upper threshold of the corresponding index.

[0146] Optionally, the detection module 510 is specifically used to determine the degree of vehicle shaking as slight shaking if the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the driving direction is greater than or equal to the lower threshold of the indicator and less than or equal to the upper threshold of the corresponding indicator; and to determine the degree of vehicle shaking as severe shaking if the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the driving direction is greater than the upper threshold of the corresponding indicator.

[0147] Optionally, the detection module 510 is further configured to, before determining the degree of vehicle swaying in the corresponding direction based on set indicators, determine that the vehicle's charcoal canister solenoid valve is in the open state and the charcoal canister vent valve is in the closed state; increment the number of times the fuel tank vacuum is established, whereby the fuel tank vacuum is used to represent the change in the fuel tank vacuum from the start to reaching the first target vacuum, and the change in the fuel tank vacuum begins when the charcoal canister solenoid valve is open and the charcoal canister vent valve is closed; correspondingly, the determination module 520 is further configured to, after determining the maximum value of the vehicle's swaying in each corresponding direction as the degree of fuel tank swaying, if the degree of fuel tank swaying is severe, stop the leak diagnosis process; if the degree of fuel tank swaying is slight, determine the extent of the leak diagnosis process based on the duration of slight swaying and the fuel tank pressure.

[0148] Optionally, the determining module 520 is specifically used to determine the ratio of the time the tank is slightly shaking when the vacuum level in the tank reaches the first target vacuum level to the total time of the process of establishing the vacuum level in the tank; if the ratio is less than a set ratio threshold, the leak diagnosis process is determined to enter the micro-leakage diagnosis process; if the ratio is greater than or equal to the set ratio threshold, the derivative of the rate of change of the tank pressure within a set time period after the vacuum level in the tank reaches the first target vacuum level is determined; if the derivative exceeds a set derivative threshold, the leak diagnosis process is stopped; if the derivative does not exceed the set derivative threshold, the tank pressure is determined to reach the second target vacuum level, and the micro-leakage diagnosis process is entered.

[0149] Optionally, the determining module 520 is further configured to: if the vacuum level in the oil tank reaches the first target vacuum level, switch the charcoal canister solenoid valve to the closed state and keep the charcoal canister ventilation valve in the closed state; after determining the derivative of the rate of change of oil tank pressure within a set time period after the vacuum level in the oil tank reaches the first target vacuum level, if the derivative does not exceed the set derivative threshold and the oil tank pressure does not reach the second target vacuum level, determine that the charcoal canister solenoid valve is in the reopened state and increment the number of times the oil tank establishes vacuum level; if the number of times the oil tank establishes vacuum level exceeds the set number, stop the leak diagnosis process.

[0150] Optionally, the detection module 510 is further configured to determine that both the charcoal canister solenoid valve and the charcoal canister vent valve are in the closed state before determining the degree of shaking of the vehicle as a whole in the corresponding direction based on the set indicators; correspondingly, the determination module 520 is further configured to determine the maximum value of the shaking degree of the vehicle in each corresponding direction as the degree of shaking of the fuel tank, and if the degree of shaking of the fuel tank is severe, then stop the leak diagnosis process.

[0151] In this embodiment, the fuel tank sway recognition device, through the combination of various modules, can quickly determine whether the fuel tank is swaying by using different set indicators, and then promptly correct or stop the leak diagnosis process, thereby ensuring the accuracy and reliability of the leak detection results and greatly expanding the application scenarios of the engine intake manifold vacuum method.

[0152] Figure 6 This is a schematic diagram of the structure of a control device provided in this disclosure, such as... Figure 6 As shown, the control device 600 includes a memory 610 and a processor 620.

[0153] The memory 610 stores a computer program that can be executed by at least one processor 620. This computer program is executed by at least one processor 620 to enable the control device to implement the fuel tank sway recognition method provided in any of the above embodiments.

[0154] The memory 610 and the processor 620 can be connected via a bus 630.

[0155] The relevant explanations can be understood by referring to the corresponding descriptions and effects in the method embodiments, and will not be repeated here.

[0156] 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: Figure 2 to Figure 4 The corresponding embodiment of the fuel tank sway recognition method.

[0157] The computer-readable storage medium can be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0158] 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: Figure 2 to Figure 3b The corresponding embodiment of the fuel tank sway recognition method.

[0159] 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.

[0160] 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.

[0161] 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 identifying fuel tank shaking, characterized in that, The method includes: Based on the set indicators, the degree of sway of the vehicle as a whole along the corresponding direction is determined, and the corresponding direction includes the direction perpendicular to the chassis, the direction of travel, and the lateral direction of travel. The maximum value of the vehicle's sway in each corresponding direction is determined as the sway of the fuel tank. Before determining the degree of overall vehicle sway in the corresponding direction based on the set indicators, the process also includes: Ensure that the vehicle's charcoal canister solenoid valve is in the open position and the charcoal canister vent valve is in the closed position; Increment the number of times the oil tank establishes a vacuum. The process of establishing a vacuum in the oil tank is used to represent the change in the vacuum level in the oil tank from the beginning to the arrival of the first target vacuum level. The change in the vacuum level in the oil tank begins when the canister solenoid valve is opened and the canister ventilation valve is closed. Accordingly, after determining the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank, the method further includes: If the shaking of the oil tank is severe, the leak diagnosis process shall be stopped. If the shaking degree of the oil tank is slight, then the ratio of the time the oil tank is in slight shaking to the total time of the process of the oil tank establishing vacuum when the vacuum degree inside the oil tank reaches the first target vacuum degree is determined. If the ratio is less than a set ratio threshold, the leak diagnosis process is determined to enter the micro-leak diagnosis process. If the ratio is greater than or equal to a set ratio threshold, determine the derivative of the rate of change of tank pressure within a set time period after the vacuum level in the tank reaches the first target vacuum level. If the derivative exceeds the set derivative threshold, the leak diagnosis process will stop. If the derivative does not exceed the set derivative threshold, it is determined that the tank pressure has reached the second target vacuum level, and the micro-leakage diagnosis process begins.

2. The fuel tank sway recognition method according to claim 1, characterized in that, The determination of the overall sway of the vehicle along the corresponding direction based on the set indicators includes: Determine the degree of vehicle sway in the direction perpendicular to the chassis based on the acceleration of the wheels and / or the acceleration of the vehicle in the vertical direction. The degree of vehicle sway along the driving direction is determined based on throttle opening, accelerator opening, brake master cylinder pressure and / or acceleration along the driving direction. The degree of lateral sway of the vehicle along the direction of travel is determined based on the steering wheel angle and / or the lateral acceleration along the direction of travel.

3. The fuel tank sway recognition method according to claim 2, characterized in that, Determining the degree of vehicle sway along the direction perpendicular to the chassis based on wheel acceleration and / or overall acceleration includes: If the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis is greater than or equal to the lower threshold of the index, and less than or equal to the upper threshold of the corresponding index, then the degree of vehicle swaying is determined to be slight swaying. If the maximum absolute value of wheel acceleration and / or the acceleration of the vehicle as a whole in the direction perpendicular to the chassis exceeds the upper limit threshold of the corresponding index, the vehicle swaying is determined to be severe swaying.

4. The fuel tank sway recognition method according to claim 2, characterized in that, The determination of the degree of vehicle sway in the driving direction based on throttle opening, accelerator opening, brake master cylinder pressure, and / or acceleration in the driving direction includes: If the rate of change of the vehicle's throttle opening, the rate of change of the accelerator opening, the rate of change of the brake master cylinder pressure, and / or the acceleration of the vehicle as a whole along the direction of travel are greater than or equal to the lower threshold of the corresponding indicators, and less than or equal to the upper threshold of the corresponding indicators, then the degree of vehicle shaking is determined to be slight shaking. If the rate of change of the vehicle's throttle opening, the rate of change of the accelerator opening, the rate of change of the brake master cylinder pressure, and / or the overall acceleration of the vehicle along the direction of travel exceeds the upper limit threshold of the corresponding indicator, then the degree of vehicle shaking is determined to be severe shaking.

5. The fuel tank sway recognition method according to claim 2, characterized in that, Determining the degree of lateral sway of the vehicle along the driving direction based on the steering wheel angle and / or lateral acceleration along the driving direction includes: If the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the direction of travel is greater than or equal to the lower threshold of the indicator, and less than or equal to the upper threshold of the corresponding indicator, then the degree of vehicle swaying is determined to be slight swaying. If the rate of change of steering wheel angle and / or the lateral acceleration of the vehicle as a whole along the direction of travel is greater than the upper limit threshold of the corresponding indicator, the degree of vehicle shaking is determined to be severe shaking.

6. The fuel tank sway recognition method according to claim 1, characterized in that, When the vacuum level in the fuel tank reaches the first target vacuum level, the solenoid valve of the charcoal canister is switched to the closed state, and the charcoal canister ventilation valve remains closed. After determining the derivative of the rate of change of tank pressure over a set time period after the vacuum level in the tank reaches the first target vacuum level, the method further includes: If the derivative does not exceed the set derivative threshold and the tank pressure does not reach the second target vacuum level, it is determined that the carbon canister solenoid valve is in the reopened state, and the number of times the tank vacuum level is established is incremented by one. If the number of times the oil tank establishes a vacuum exceeds the set number, the leak diagnosis process will stop.

7. The fuel tank sway identification method according to any one of claims 1 to 5, characterized in that, Before determining the degree of overall vehicle sway in the corresponding direction based on the set indicators, the process also includes: Ensure that both the charcoal canister solenoid valve and the charcoal canister ventilation valve are in the closed position; Accordingly, after determining the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank, the method further includes: If the shaking of the oil tank is severe, the leak diagnosis process should be stopped.

8. A fuel tank shaking detection device, characterized in that, include: The detection module is used to determine the degree of sway of the vehicle as a whole along a corresponding direction based on a set index. The corresponding direction includes the direction perpendicular to the chassis, the direction of travel, and the lateral direction of travel. The determining module is used to determine the maximum value of the vehicle's sway in each corresponding direction as the sway level of the fuel tank; The detection module is also used to determine that the vehicle's charcoal canister solenoid valve is in the open state and the charcoal canister vent valve is in the closed state before determining the degree of shaking of the vehicle as a whole in the corresponding direction based on the set indicators; and to increment the number of times the fuel tank vacuum degree establishment process is performed, wherein the fuel tank vacuum degree establishment process is used to represent the change of the vacuum degree in the fuel tank from the beginning to the arrival of the first target vacuum degree, wherein the change of the vacuum degree in the fuel tank begins when the charcoal canister solenoid valve is open and the charcoal canister vent valve is closed; The determining module is further configured to, after determining the maximum value of the vehicle's swaying degree in each corresponding direction as the swaying degree of the fuel tank, if the swaying degree of the fuel tank is severe, stop the leak diagnosis process; if the swaying degree of the fuel tank is slight, determine the ratio of the duration of slight swaying of the fuel tank when the vacuum degree inside the fuel tank reaches the first target vacuum degree to the total duration of the process of establishing the vacuum degree of the fuel tank; if the ratio is less than a set ratio threshold, determine that the leak diagnosis process enters the minor leak diagnosis process; if the ratio is greater than or equal to the set ratio threshold, determine the derivative of the rate of change of the fuel tank pressure within a set time period after the vacuum degree inside the fuel tank reaches the first target vacuum degree; if the derivative exceeds a set derivative threshold, stop the leak diagnosis process; if the derivative does not exceed the set derivative threshold, determine that the fuel tank pressure has reached the second target vacuum degree, and enter the minor leak diagnosis process.

9. 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 that can be executed by the at least one processor, which, when executed by the at least one processor, cause the control device to perform the fuel tank sway recognition method as described in any one of claims 1 to 7.

10. 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 fuel tank sway recognition method as described in any one of claims 1 to 7.

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