Method, apparatus, device, and medium for leak diagnosis for evaporation system

Abstract

The application relates to the technical field of vehicle diagnosis, and discloses a leakage diagnosis method, device, equipment and medium for an evaporation system. The application performs pumping work or air extraction work on the inside of the entire evaporation system through a pump air device arranged on a carbon tank, collects the internal pressure of the evaporation system through a first pressure sensor arranged on the carbon tank, obtains a system pressure parameter, performs leakage diagnosis on the entire evaporation system through the system pressure parameter, obtains a leakage diagnosis result, and compared with performing leakage diagnosis on the entire evaporation system through an oil tank pressure sensor in a high-pressure oil tank, not only can the entire evaporation system including the carbon tank and the high-pressure oil tank be subjected to leakage diagnosis, but also the problem that the accuracy and timeliness are poor due to poor accuracy of the oil tank pressure sensor can be avoided, so that the leakage diagnosis capability for the evaporation system is improved in two aspects.

Description

Technical Field

[0001] This invention relates to the field of vehicle diagnostic technology, and in particular to a method, apparatus, equipment and medium for leak diagnosis of evaporation systems. Background Technology

[0002] In recent years, with increasingly stringent environmental protection requirements and continued user anxiety about vehicle range, hybrid vehicles have gradually become the mainstream choice in the market. Because their engines operate less frequently, traditional carbon canister adsorption and desorption alone are insufficient to meet regulatory requirements for evaporative emissions. To meet these requirements, a combination of a high-pressure fuel tank, a fuel tank isolation valve, and a fuel tank pressure sensor is now commonly used. The high-pressure fuel tank effectively reduces fuel evaporative emissions, while the fuel tank isolation valve controls the flow of fuel vapor. The fuel tank pressure sensor monitors the fuel pressure inside the tank in real time. When the tank pressure is too high or too low, the system can appropriately control the opening of the fuel tank isolation valve to ensure fuel tank safety and normal fuel pump supply.

[0003] However, on the one hand, the high-pressure fuel tank and the carbon canister are isolated by a fuel tank isolation valve to prevent fuel vapor from entering the carbon canister. This means that the fuel tank pressure sensor located in the high-pressure fuel tank cannot diagnose leaks in the entire vapor system, including the carbon canister. On the other hand, in addition to strict limits on evaporative emissions, regulations such as China VI, OBDII, and KOBD also impose fault monitoring requirements on the evaporative system, including evaporative leak monitoring and desorption flow monitoring. The main function of the fuel tank pressure sensor is to monitor the fuel pressure in the high-pressure fuel tank. Its design usually requires a large range to meet the measurement needs under high-pressure environments, resulting in insufficient measurement capability of the pressure sensor in the entire evaporative system. Therefore, its current ability to diagnose leaks in the evaporative system is relatively weak. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] In view of the shortcomings of the prior art described above, this application discloses a method, apparatus, equipment and medium for leak diagnosis of evaporation systems, so as to improve the leak diagnosis capability of evaporation systems.

[0006] This application discloses a leak diagnosis method for an evaporation system, the evaporation system including a fuel tank and a carbon canister, and a fuel line between the fuel tank and the carbon canister. The method includes: installing a first pressure sensor and a pumping device in the carbon canister; using the pumping device to perform pumping or evacuating operations on the interior of the evaporation system, and using the first pressure sensor to collect the internal pressure of the evaporation system to obtain system pressure parameters; and performing leak diagnosis on the evaporation system based on the system pressure parameters to obtain a leak diagnosis result.

[0007] In one embodiment of this application, the method further includes at least one of the following: the fuel tank is provided with a second pressure sensor; the carbon canister is connected to the fuel tank via a fuel line, wherein the fuel line is provided with a fuel tank isolation valve; and the carbon canister is connected to a desorption line via a carbon canister solenoid valve.

[0008] In one embodiment of this application, the method further includes at least one of the following: if there is a refueling record in the fuel tank within a preset time period, then the leakage diagnosis state of the fuel tank is set to the open state; if the second pressure sensor malfunctions, then the leakage diagnosis state of the fuel tank is set to the open state; the internal pressure of the fuel tank is collected using the second pressure sensor to obtain fuel tank pressure parameters, and if the fuel tank pressure parameters are within the fuel tank pressure range, then the leakage diagnosis state of the fuel tank is set to the open state, wherein the fuel tank pressure range is determined according to the ambient pressure of the fuel tank.

[0009] In one embodiment of this application, before using the pumping device to perform pumping or evacuation operations on the interior of the evaporation system, the method further includes: if the fuel tank leak diagnosis status is open, then controlling the fuel line between the fuel tank and the carbon canister to be connected through the fuel tank isolation valve; if the fuel tank leak diagnosis status is closed, then controlling the fuel line between the fuel tank and the carbon canister to be interrupted through the fuel tank isolation valve.

[0010] In one embodiment of this application, leakage diagnosis of the evaporation system is performed based on the system pressure parameters to obtain leakage diagnosis results, including at least one of the following: if the pressure change corresponding to the system pressure parameters is less than a preset pressure fault threshold, then the evaporation system has a leakage fault; the gas leakage amount of the evaporation system is calculated based on the system pressure parameters, and if the leakage change rate corresponding to the gas leakage amount is greater than or equal to a preset leakage fault threshold, then the evaporation system has a leakage fault.

[0011] In one embodiment of this application, the gas leakage of the evaporation system is calculated based on the system pressure parameters, including: obtaining the operating load of the pumping device; calculating the operating load and the system pressure parameters using the ideal gas law and fluid dynamics principles to obtain the predicted leakage; and iteratively calculating the predicted leakage using the least squares method to obtain the gas leakage.

[0012] In one embodiment of this application, leak diagnosis of the evaporation system is performed based on the system pressure parameters to obtain a leak diagnosis result, including: if the pressure change corresponding to the system pressure parameters is less than a preset pressure fault threshold, then the evaporation system has a large leak fault; if the pressure change corresponding to the system pressure parameters is greater than or equal to the pressure fault threshold, then the gas leakage amount of the evaporation system is calculated based on the system pressure parameters; if the leakage rate corresponding to the gas leakage amount is greater than or equal to a preset leakage fault threshold, then the evaporation system has a small leak fault; if the leakage rate corresponding to the gas leakage amount is less than the leakage fault threshold, then the evaporation system does not have a leak fault.

[0013] This application discloses a leak diagnosis device for an evaporation system, the evaporation system including a fuel tank and a carbon canister, with a fuel line between the fuel tank and the carbon canister. The leak diagnosis device for the evaporation system includes: a pumping device disposed in the carbon canister, the pumping device being configured to perform pumping or evacuating operations on the interior of the evaporation system; a first pressure sensor disposed in the carbon canister, the first pressure sensor being configured to collect the internal pressure of the evaporation system to obtain system pressure parameters; and a diagnosis execution module configured to perform leak diagnosis on the evaporation system based on the system pressure parameters to obtain a leak diagnosis result.

[0014] This application discloses an electronic device, including: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to cause the electronic device to perform the above-described method.

[0015] The present invention discloses a computer-readable storage medium having a computer program stored thereon: when the computer program is executed by a processor, it implements the above-described method.

[0016] The beneficial effects of this application are:

[0017] By using a pumping device installed in the carbon canister to pump or extract air from the entire evaporation system, and by collecting the internal pressure of the evaporation system through a first pressure sensor installed in the carbon canister, system pressure parameters are obtained. These system pressure parameters are then used to diagnose leaks in the entire evaporation system, yielding leak diagnosis results. In this way, compared to diagnosing leaks in the entire evaporation system using a tank pressure sensor within the high-pressure oil tank, the leak diagnosis function of the evaporation system is separated by using a first pressure sensor. By utilizing the pumping device and the first pressure sensor to collect the internal pressure of the evaporation system and diagnosing leaks based on the collected system pressure parameters, leak diagnosis can be performed on the entire evaporation system, including the carbon canister and the high-pressure oil tank. Furthermore, it avoids the problems of poor accuracy and timeliness caused by the poor precision of the tank pressure sensor, thus improving the leak diagnosis capability of the evaporation system in two ways. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an evaporation system in an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of another evaporation system in an embodiment of this application;

[0020] Figure 3 This is a flowchart illustrating a leak diagnosis method for an evaporation system according to an embodiment of this application.

[0021] Figure 4 This is a flowchart illustrating another leak diagnosis method for an evaporation system in an embodiment of this application;

[0022] Figure 5 This is a flowchart illustrating a method for determining the leakage status of a fuel tank in an embodiment of this application.

[0023] Figure 6 This is a schematic diagram of a leak diagnosis device for an evaporation system according to an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the structure of an electronic device in an embodiment of the present invention. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and sub-samples in the embodiments can be combined with each other.

[0026] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0027] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0028] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0029] Unless otherwise stated, the term "multiple" means two or more.

[0030] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0031] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0032] Combination Figure 1 As shown, this disclosure provides an evaporation system including a carbon canister 101, a desorption line 102, a fuel tank 103, and an intake manifold 104.

[0033] The carbon canister 101 is equipped with a first pressure sensor (P-sensor, Pressure Sensor) 1011 and a leak diagnosis module (DMTL, Diagnostic Module for Tank Leakage) 1012.

[0034] The first pressure sensor 1011 has a smaller range and higher accuracy compared to the second pressure sensor located in the fuel tank.

[0035] The leak diagnosis module 1012 is located at the atmospheric port of the carbon canister 101. The leak diagnosis module 1012 includes an atmospheric solenoid valve and a pumping device. The pumping device performs pumping or evacuation operations on the carbon canister by operating an internal motor.

[0036] When not activated, the atmospheric solenoid valve is in a default closed state, allowing the carbon canister to be fully connected to the atmosphere to ensure that the normal carbon canister flushing function is not affected. At the same time, when the atmospheric solenoid valve is activated and opened, the main channel connecting the carbon canister to the atmosphere is closed.

[0037] The air pumping device uses a motor to pump or extract air from the carbon canister.

[0038] The carbon canister 101 is connected to the fuel tank 103 via the fuel tank isolation valve (FTIV) 1031.

[0039] The fuel tank 103 is equipped with a second pressure sensor, which is used to collect the internal pressure of the fuel tank 103.

[0040] The oil tank isolation valve 1031 is normally in the closed state, and switches to the open state when it receives an opening command.

[0041] The carbon canister 101 is connected to the intake manifold 104 via a carbon canister purge valve (CPV) 1013 and a desorption line 102.

[0042] The intake manifold 104 is equipped with a throttle valve 1041.

[0043] Combination Figure 2 As shown, this disclosure provides an evaporation system, including a carbon canister 101, a desorption pipeline 102, a fuel tank 103, an intake manifold 104, and a compressor 105.

[0044] A first pressure sensor 1011 is installed inside the carbon canister 101.

[0045] The carbon canister 101 is connected to the fuel tank 103 via the fuel tank isolation valve 1031.

[0046] The desorption pipeline 102 includes a low desorption pipeline 1021 and a high desorption pipeline 1022.

[0047] The carbon canister 101 is connected to the intake manifold 104 via the carbon canister solenoid valve 1013 and the low desorption line 1021.

[0048] The intake manifold 104 is equipped with a throttle valve 1041.

[0049] The carbon canister 101 is connected to the venturi tube and the booster compressor in sequence through the carbon canister solenoid valve 1013 and the high desorption pipeline 1022.

[0050] A venturi tube is a specially shaped pipe with a gradually narrowing and then widening section inside. This creates a pressure difference as the fluid passes through the pipe, allowing for flow measurement or control. In automotive engine systems, venturi tubes are used in fuel injection or intake systems to achieve precise control of fuel flow or air volume.

[0051] Combination Figure 3 As shown, this disclosure provides a leak diagnosis method for an evaporation system, including:

[0052] Step S301: Use a pumping device to pump or extract air from the inside of the evaporation system.

[0053] Step S302: The internal pressure of the evaporation system is collected using the first pressure sensor to obtain the system pressure parameters;

[0054] Step S303: Perform leak diagnosis on the evaporation system based on the system pressure parameters to obtain the leak diagnosis results.

[0055] The leak diagnosis method for evaporation systems provided in this disclosure involves pumping or evacuating the entire evaporation system using a pumping device located in the carbon canister, and collecting the internal pressure of the evaporation system using a first pressure sensor located in the carbon canister. This system pressure parameter is then used to diagnose leaks in the entire evaporation system, yielding a leak diagnosis result. Compared to diagnosing leaks in the entire evaporation system using a tank pressure sensor within the high-pressure oil tank, this method isolates the leak diagnosis function of the evaporation system using a first pressure sensor. By utilizing the pumping device and the first pressure sensor to collect the internal pressure of the evaporation system and diagnosing leaks based on the collected system pressure parameters, it not only diagnoses leaks in the entire evaporation system, including the carbon canister and the high-pressure oil tank, but also avoids the problems of poor accuracy and timeliness caused by the poor precision of the tank pressure sensor. Therefore, it improves the leak diagnosis capability of the evaporation system in two ways.

[0056] Combination Figure 4 As shown, this disclosure provides a leak diagnosis method for an evaporation system, including:

[0057] Step S401: A first pressure sensor and a pumping device are installed in the carbon canister. Proceed to step S402.

[0058] In some embodiments, the carbon canister solenoid valve is closed to disconnect the passage between the carbon canister and the desorption line.

[0059] Step S402: Determine whether the evaporation system meets the leakage diagnosis enable conditions. If yes, proceed to step S403; otherwise, proceed to step S402.

[0060] In some embodiments, the leak diagnosis enabling conditions include at least one of the following: the downtime of the vehicle where the evaporation system is located meets a preset downtime duration; the ambient temperature meets a preset temperature condition; the fuel level meets a preset level condition; the power supply voltage meets a preset voltage condition; the leak diagnosis module is in normal operation; and the first pressure sensor is in a fault-free state.

[0061] Step S403: Determine whether the fuel tank leak diagnosis status is in the open state. If yes, proceed to step S404; otherwise, proceed to step S405.

[0062] Optionally, the method further includes at least one of the following: if there is a refueling record in the fuel tank within a preset time period, then the fuel tank leakage diagnosis status is set to the open state; if the second pressure sensor malfunctions, then the fuel tank leakage diagnosis status is set to the open state; the internal pressure of the fuel tank is collected using the second pressure sensor to obtain fuel tank pressure parameters, and if the fuel tank pressure parameters are within the fuel tank pressure range, then the fuel tank leakage diagnosis status is set to the open state, wherein the fuel tank pressure range is determined according to the ambient pressure of the fuel tank.

[0063] Combination Figure 5 As shown in the embodiments of this disclosure, a method for determining the leakage status of a fuel tank is provided, including:

[0064] Step S501: In response to a new driving cycle, obtain the refueling record of the previous driving cycle;

[0065] If the duration of the vehicle being in a stopped state exceeds a preset duration threshold, the moment when the vehicle is powered on will be taken as the starting position of the driving cycle, and the moment when the vehicle enters the next starting position will be taken as the ending position of the driving cycle.

[0066] Step S502: Determine whether there is a refueling record in the fuel tank during the previous driving cycle. If yes, proceed to step S506; otherwise, proceed to step S503.

[0067] Step S503: Determine if the second pressure sensor is faulty. If yes, proceed to step S506; otherwise, proceed to step S504.

[0068] Step S504: The internal pressure of the fuel tank is collected using the second pressure sensor to obtain the fuel tank pressure parameters;

[0069] Step S505: Determine whether the oil tank pressure parameter is within the oil tank pressure range. If yes, proceed to step S506; otherwise, proceed to step S507.

[0070] The fuel tank pressure range is determined based on the ambient pressure of the fuel tank.

[0071] Step S506: Set the fuel tank leak diagnosis status to the on state.

[0072] Step S507: Set the fuel tank leak diagnosis status to the off state.

[0073] In some embodiments, it is determined whether there is a refueling record in the fuel tank within a preset time period, i.e., whether there is a refueling behavior record in the previous driving cycle, for example, if the refueling demand signal has been set for a long time; if there is a refueling record, it is determined that there may be a leak on the fuel tank side, and the fuel tank needs to be diagnosed for leak; if there is no refueling record, the vehicle where the evaporation system is located is waited for the downtime to meet the preset downtime before the vehicle is powered on again; if the pressure difference between the pressure signal collected by the second pressure sensor and the ambient atmospheric pressure is less than the pressure difference threshold, it is determined that there may be a leak on the fuel tank side, and the fuel tank needs to be diagnosed for leak. The pressure difference threshold needs to be calibrated by experimentally testing the pressure performance of the fuel tank under different leak hole environments, and the pressure difference threshold needs to meet the measurement accuracy of the first pressure sensor.

[0074] In some embodiments, the fuel tank pressure range is determined based on the ambient pressure of the fuel tank and fluctuates up and down according to a pressure difference threshold.

[0075] In some embodiments, if the second pressure sensor issues a fault notification after fault detection, the pressure signal collected by the second pressure sensor is inaccurate and cannot be accurately determined based on its signal to determine whether there is a leak on the fuel tank side. Therefore, it is uniformly determined that there may be a leak in the fuel tank and a leak diagnosis of the fuel tank is required.

[0076] Step S404: Control the fuel line between the fuel tank and the carbon canister through the fuel tank isolation valve, then proceed to step S406.

[0077] Optionally, before using the pumping device to perform pumping or evacuation operations on the interior of the evaporation system, the method further includes: if the fuel tank leak diagnosis status is open, controlling the fuel line between the fuel tank and the carbon canister to be connected via the fuel tank isolation valve.

[0078] In some embodiments, if the vehicle is off and the fuel tank leak diagnosis status is on, the fuel tank isolation valve is controlled to open the fuel line, and the internal pressure of the fuel tank is allowed to stabilize from high pressure to atmospheric pressure before leak diagnosis is performed.

[0079] In step S405, the fuel line between the fuel tank and the carbon canister is interrupted by controlling the fuel tank isolation valve, and then the process jumps to step S406.

[0080] Optionally, before using the pumping device to perform pumping or evacuation operations on the interior of the evaporation system, the method further includes: if the fuel tank leak diagnosis status is closed, then controlling the interruption of the fuel line between the fuel tank and the carbon canister via the fuel tank isolation valve.

[0081] In some embodiments, if the vehicle is off and the fuel tank leak diagnosis status is off, the fuel tank isolation valve is controlled to close the fuel line, and leak diagnosis is only performed on the internal space between the fuel tank isolation valve and the carbon canister solenoid valve, thereby reducing the opening time of the fuel line and preventing fuel vapor from leaking into the carbon canister. At the same time, it can also meet the requirements of NVH and evaporative emissions.

[0082] Step S406: Pump or extract air from the inside of the evaporation system using the pumping device of the leak diagnosis module, then proceed to step S407.

[0083] In some embodiments, a pumping device is used to pump or extract air into the leak diagnosis space, and the pump voltage signal of the pumping device is collected. Based on the pump voltage signal, the speed parameter of the motor within the pump voltage signal can be calculated, thereby calculating the pumping volume or extraction volume per unit time, i.e., the workload.

[0084] Step S407: Use the first pressure sensor to collect the internal pressure of the evaporation system to obtain the system pressure parameters, and then proceed to step S408.

[0085] In some embodiments, the system pressure parameter includes a pressure value, or the system pressure parameter includes a correspondence between the pressure value and time.

[0086] Step S408: Determine whether the pressure change is greater than or equal to the pressure fault threshold. If yes, proceed to step S410; otherwise, proceed to step S409.

[0087] Optionally, the evaporation system is leak diagnosed based on the system pressure parameters to obtain the leak diagnosis results, including: if the pressure change corresponding to the system pressure parameters is less than the preset pressure fault threshold, then the evaporation system has a leak fault.

[0088] Step S409: A major leak has occurred in the evaporation system.

[0089] In some embodiments, if the system pressure parameter is greater than or equal to the pressure fault threshold within a limited time, it is determined that there is no major leakage fault in the evaporation system. The pressure fault threshold needs to take into account various environmental conditions such as the fuel level in the fuel tank, the specifications of the pumping system, the ambient temperature, and the ambient pressure. The pressure fault threshold is determined by experiments under different environmental conditions.

[0090] In some embodiments, if the system pressure parameter is less than the pressure fault threshold within a limited time, it is determined that there is a large leakage fault in the evaporation system, wherein a large leakage fault refers to the presence of a leakage hole with a diameter of 1 mm or more in the evaporation system.

[0091] Step S410: Calculate the gas leakage of the evaporation system based on the system pressure parameters, and then proceed to step S411.

[0092] Optionally, the gas leakage of the evaporation system is calculated based on the system pressure parameters, including: obtaining the operating volume of the pumping device; calculating the operating volume and system pressure parameters using the ideal gas law and fluid mechanics principles to obtain the predicted leakage; and iteratively calculating the predicted leakage using the least squares method to obtain the gas leakage.

[0093] In some embodiments, the predicted leakage amount has multiple calculation formulas.

[0094] In some embodiments, the predicted leakage amount is calculated using formula (1):

[0095]

[0096] In formula (1), Q G C represents the leakage velocity corresponding to the leaking gas; Y is the preset gas expansion factor, which is calculated using either subcritical or critical flow, depending on the pressure build-up capability of the leak diagnosis module. This application uses subcritical flow; G Let C be the gas leakage coefficient corresponding to the leaking gas. When the crack is circular, the gas leakage coefficient C is... G =1, when the crack is triangular, the gas leakage coefficient C G =0.95, when the crack is rectangular, the gas leakage coefficient C G =0.9; A is the predicted leakage amount, i.e., the leakage area corresponding to the leaking gas; P G The pressure of the leaking gas is the pressure signal measured by the first pressure sensor; M is the relative molecular mass of the leaking gas, i.e., the molar mass of the leaking gas; κ is the adiabatic index of the gas, i.e., the heat capacity ratio; R is the ideal gas constant, which in this application is R = 8.314; T G The temperature of the leaked gas.

[0097] In some embodiments, the predicted leakage amount is calculated using formula (2):

[0098]

[0099] In formula (2), the molecules carry The net gas change rate is the pumped gas volume minus the gas volume change reflected by the pressure change; n pump V represents the workload of the air pumping unit; V represents the internal volume of the leak diagnosis space.

[0100] Step S411: Determine whether the rate of change of leakage is greater than or equal to the preset leakage fault threshold. If yes, proceed to step S412; otherwise, proceed to step S413.

[0101] Optionally, the evaporation system is leak diagnosed based on the system pressure parameters to obtain the leak diagnosis results, including: calculating the gas leakage amount of the evaporation system based on the system pressure parameters, and if the rate of change of the leakage amount corresponding to the gas leakage amount is greater than or equal to a preset leakage fault threshold, then the evaporation system has a leak fault.

[0102] Step S412: A minor leak has occurred in the evaporation system.

[0103] In some embodiments, if the gas leakage area is greater than or equal to a preset leakage area threshold within a preset time period, it is determined that there is a small leakage fault in the evaporation system, wherein a small leakage fault refers to a leakage hole in the evaporation system with a diameter between 0.5 and 1 mm.

[0104] In some embodiments, the leakage failure threshold is determined experimentally.

[0105] Step S413: There is no leakage fault in the evaporation system.

[0106] In some embodiments, if the gas leakage area is less than a preset leakage area threshold within a preset time period, it is determined that there is no leakage fault in the evaporation system.

[0107] Optionally, leakage diagnosis of the evaporation system is performed based on the system pressure parameters to obtain leakage diagnosis results, including: if the pressure change corresponding to the system pressure parameters is less than a preset pressure fault threshold, then the evaporation system has a large leakage fault; if the pressure change corresponding to the system pressure parameters is greater than or equal to the pressure fault threshold, then the gas leakage amount of the evaporation system is calculated based on the system pressure parameters; if the leakage rate corresponding to the gas leakage amount is greater than or equal to a preset leakage fault threshold, then the evaporation system has a small leakage fault; if the leakage rate corresponding to the gas leakage amount is less than the leakage fault threshold, then the evaporation system does not have a leakage fault.

[0108] Combination Figure 6 The present invention discloses a leak diagnosis device for an evaporation system, the evaporation system including a fuel tank and a carbon canister, and a fuel line between the fuel tank and the carbon canister. The leak diagnosis device for the evaporation system includes a pumping device 601, a first pressure sensor 602, and a diagnostic execution module 603.

[0109] The air pumping device 601 is installed in the carbon canister and is configured to perform air pumping or evacuation operations on the interior of the evaporation system.

[0110] The first pressure sensor 602 is installed in the carbon canister and is configured to collect the internal pressure of the evaporation system to obtain system pressure parameters.

[0111] The diagnostic execution module 603 is configured to perform leak diagnosis on the evaporation system based on the system pressure parameters and obtain the leak diagnosis results.

[0112] The leak diagnosis device for an evaporation system provided in this embodiment of the invention uses a pumping device installed in the carbon canister to pump or evacuate air from the entire evaporation system. A first pressure sensor installed in the carbon canister collects the internal pressure of the evaporation system to obtain system pressure parameters. These system pressure parameters are then used to diagnose leaks in the entire evaporation system, yielding a leak diagnosis result. Compared to diagnosing leaks in the entire evaporation system using a tank pressure sensor within the high-pressure oil tank, this method isolates the leak diagnosis function of the evaporation system using a first pressure sensor. By utilizing the pumping device and the first pressure sensor to collect the internal pressure of the evaporation system and diagnosing leaks based on the collected system pressure parameters, it can diagnose leaks in the entire evaporation system, including the carbon canister and the high-pressure oil tank. Furthermore, it avoids the problems of poor accuracy and timeliness caused by the poor precision of the tank pressure sensor, thus improving the leak diagnosis capability of the evaporation system in two ways.

[0113] This disclosure also provides an electronic device, including: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device performs the above-described method.

[0114] Figure 7 A schematic diagram of a computer system suitable for implementing the embodiments of this application is shown. It should be noted that... Figure 7 The computer system 700 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0115] like Figure 7As shown, the computer system 700 includes a Central Processing Unit (CPU) 701, which can perform various appropriate actions and processes, such as executing the methods described in the above embodiments, based on programs stored in Read-Only Memory (ROM) 702 or programs loaded from storage portion 708 into Random Access Memory (RAM) 703. The RAM 703 also stores various programs and data required for system operation. The CPU 701, ROM 702, and RAM 703 are interconnected via a bus 704. An Input / Output (I / O) interface 705 is also connected to the bus 704.

[0116] The following components are connected to the input / output interface 705: an input section 706 including a keyboard, mouse, etc.; an output section 707 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the input / output interface 705 as needed. A removable medium 711, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 710 as needed so that computer programs read from it can be installed into the storage section 708 as needed.

[0117] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program including a computer program for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 709, and / or installed from removable medium 711. When the computer program is executed by central processing unit (CPU) 701, it performs various functions defined in the system of this application.

[0118] This disclosure also provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements any of the methods in this embodiment.

[0119] The computer-readable storage medium in the embodiments of this disclosure will be understood by those skilled in the art: all or part of the steps of the above method embodiments can be implemented by hardware related to computer programs. The aforementioned computer program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disk, or optical disk.

[0120] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and subsamples of some embodiments may be included in or replace parts and subsamples of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated subsamples, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other subsamples, wholes, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes the element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0121] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0122] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some sub-samples may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0123] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A leak diagnosis method for an evaporation system, characterized in that, The evaporation system includes a fuel tank and a carbon canister, and a fuel line exists between the fuel tank and the carbon canister. The method includes: A first pressure sensor and a pumping device are installed in the carbon canister. The pumping device is used to pump or extract air from the inside of the evaporation system, and the first pressure sensor is used to collect the internal pressure of the evaporation system to obtain system pressure parameters. Leak diagnosis is performed on the evaporation system based on the system pressure parameters to obtain the leak diagnosis results.

2. The method according to claim 1, characterized in that, The method further includes at least one of the following: The fuel tank is equipped with a second pressure sensor; The carbon canister is connected to the fuel tank via a fuel line, wherein the fuel line is equipped with a fuel tank isolation valve; The carbon canister is connected to the desorption pipeline via a carbon canister solenoid valve.

3. The method according to claim 2, characterized in that, The method further includes at least one of the following: If the fuel tank has a refueling record within a preset time period, then the fuel tank's leak diagnosis status is set to the open state. If the second pressure sensor malfunctions, the fuel tank leak diagnosis status is set to the open state; The internal pressure of the fuel tank is collected using the second pressure sensor to obtain the fuel tank pressure parameter. If the fuel tank pressure parameter is within the fuel tank pressure range, the fuel tank leakage diagnosis status is set to the open state. The fuel tank pressure range is determined according to the ambient pressure of the fuel tank.

4. The method according to claim 2, characterized in that, Before using the pumping device to perform pumping or evacuation operations inside the evaporation system, the method further includes: If the fuel tank's leak diagnosis status is open, then the fuel line between the fuel tank and the carbon canister is connected via the fuel tank isolation valve. If the fuel tank's leak diagnosis status is closed, the fuel line between the fuel tank and the carbon canister will be interrupted via the fuel tank isolation valve.

5. The method according to any one of claims 1 to 4, characterized in that, Based on the system pressure parameters, a leak diagnosis is performed on the evaporation system to obtain a leak diagnosis result, including at least one of the following: If the pressure change corresponding to the system pressure parameter is less than the preset pressure fault threshold, then the evaporation system has a leakage fault. The gas leakage of the evaporation system is calculated based on the system pressure parameters. If the rate of change of the leakage corresponding to the gas leakage is greater than or equal to a preset leakage fault threshold, then the evaporation system has a leakage fault.

6. The method according to claim 5, characterized in that, The gas leakage of the evaporation system is calculated based on the system pressure parameters, including: Obtain the operating volume of the pumping device; The predicted leakage amount is obtained by calculating the workload and system pressure parameters using the ideal gas law and fluid mechanics principles. The predicted leakage amount is calculated iteratively using the least squares method to obtain the gas leakage amount.

7. The method according to any one of claims 1 to 4, characterized in that, Based on the system pressure parameters, a leak diagnosis is performed on the evaporation system to obtain the leak diagnosis results, including: If the pressure change corresponding to the system pressure parameter is less than the preset pressure fault threshold, then the evaporation system has a large leakage fault. If the pressure change corresponding to the system pressure parameter is greater than or equal to the pressure fault threshold, the gas leakage of the evaporation system is calculated based on the system pressure parameter. If the rate of change of the gas leakage is greater than or equal to the preset leakage fault threshold, then the evaporation system has a minor leakage fault. If the rate of change of the gas leakage is less than the leakage fault threshold, then the evaporation system does not have a leakage fault.

8. A leak diagnosis device for an evaporation system, characterized in that, The evaporation system includes a fuel tank and a carbon canister, and a fuel line exists between the fuel tank and the carbon canister. The leak diagnosis device for the evaporation system includes: A pumping device is provided in the carbon canister, and the pumping device is configured to perform pumping or evacuating operations on the interior of the evaporation system. A first pressure sensor is disposed in the carbon canister and is configured to collect the internal pressure of the evaporation system to obtain system pressure parameters. The diagnostic execution module is configured to perform leak diagnosis on the evaporation system based on the system pressure parameters and obtain the leak diagnosis result.

9. An electronic device, characterized in that, include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to cause the electronic device to perform the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 7.

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