Engine misfire fault detection method and device, terminal equipment and vehicle

Abstract

The invention provides an engine misfire fault detection method and device, terminal equipment and a vehicle. The method comprises the steps that the current driving mode of the vehicle is determined; the current driving mode comprises a series mode, a parallel mode and a mode switching mode; acquiring a misfire diagnosis threshold value corresponding to the current driving mode; determining a current misfire signal according to the current crankshaft rotating speed of the engine; and determining whether the engine has a misfire fault or not according to the current misfire signal and the misfire diagnosis threshold value. According to the method, the corresponding misfire diagnosis threshold value is determined according to different current driving modes of the vehicle, such as a series mode, a parallel mode and mode switching, the current misfire signal is not judged by using a single misfire diagnosis threshold value, so that whether the engine has the misfire fault or not can be more accurately detected, and the driving safety of the vehicle is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of engine detection technology, and in particular to an engine misfire fault detection method, device, terminal equipment and vehicle. Background Art

[0002] Engine misfire, also known as engine cylinder loss or engine misfire, refers to the failure of the fuel and air mixture to burn normally in one or more cylinders of the engine, resulting in the cylinder not completing its normal power stroke. When an engine misfires, it can cause vehicle power to drop, emissions to increase, engine jitter, and catalyst damage, seriously affecting driving safety. In the current technical solution, a misfire diagnostic threshold is pre-set, and after determining the current misfire signal based on the current crankshaft speed of the engine, it is determined whether the engine has a misfire fault based on the current misfire signal and the misfire diagnostic threshold. However, this technical solution cannot accurately detect whether the engine has a misfire fault, and there may be false alarms or missed alarms, which will also affect vehicle driving safety.

[0003] Therefore, how to more accurately detect whether there is an engine misfire and ensure vehicle driving safety is a technical problem that technical personnel in this field currently need to solve. Summary of the invention

[0004] The purpose of the present application is to provide an engine misfire fault detection method, apparatus, terminal equipment, computer-readable storage medium, computer program product and a vehicle, aiming to improve the accuracy of engine misfire fault detection and ensure vehicle driving safety.

[0005] In a first aspect, the present application provides a method for detecting engine misfire. The method comprises:

[0006] Determining a current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode, and a mode switching mode;

[0007] acquiring a misfire diagnosis threshold corresponding to the current driving mode;

[0008] determining a current misfire signal based on a current crankshaft speed of the engine;

[0009] It is determined whether a misfire fault exists in the engine according to the current misfire signal and the misfire diagnosis threshold.

[0010] In one embodiment, determining whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold comprises:

[0011] If the current misfire signal is greater than the misfire diagnosis threshold, updating the misfire failure count;

[0012] If the misfire failure count is greater than or equal to a preset count threshold, it is determined that a misfire fault exists in the engine.

[0013] In one embodiment, if it is determined that the current driving mode is in mode switching, obtaining the misfire diagnosis threshold corresponding to the current driving mode includes:

[0014] After waiting for a preset time period, a misfire diagnosis threshold corresponding to the current driving mode is obtained.

[0015] In one embodiment, if it is determined that the current driving mode is in mode switching, the method further includes:

[0016] modifying the misfire diagnosis threshold or the current misfire signal;

[0017] The determining whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold comprises:

[0018] It is determined whether the engine has a misfire fault according to the corrected misfire diagnosis threshold or the corrected current misfire signal.

[0019] In one embodiment, before determining the current driving mode of the vehicle, the method further includes:

[0020] Acquiring operating parameters of the engine and determining whether the operating parameters are within corresponding preset ranges;

[0021] If the operating parameter is within the preset range, the step of determining the current driving mode of the vehicle is entered.

[0022] In one embodiment, determining the current misfire signal according to the current crankshaft speed of the engine includes:

[0023] Determine the current segment time according to the current crankshaft speed;

[0024] Obtain the previous segment time corresponding to the current segment time;

[0025] A current misfire signal is determined based on the current segment time and the previous segment time.

[0026] In a second aspect, the present application also provides an engine misfire fault detection device. The device comprises:

[0027] A mode determination module, used to determine a current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode and a mode switching mode;

[0028] A threshold acquisition module, used to acquire a misfire diagnosis threshold corresponding to the current driving mode;

[0029] a signal determination module, configured to determine a current misfire signal according to a current crankshaft speed of the engine;

[0030] The detection module is used to determine whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold.

[0031] In a third aspect, the present application further provides a terminal device, wherein the terminal device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0032] In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0033] In a fifth aspect, the present application further provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0034] In a sixth aspect, the present application also provides a vehicle, comprising a vehicle body and a controller, wherein the controller executes the steps of the above method.

[0035] The embodiment of the present application provides an engine misfire fault detection method, which determines a corresponding misfire diagnosis threshold value according to the current driving mode of the vehicle, and after determining the current misfire signal according to the current crankshaft speed of the engine, determines whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold value; because the motor will adjust and correct the crankshaft speed and load to different degrees for different driving modes, thereby affecting the current misfire signal of the engine; the method determines the corresponding misfire diagnosis threshold value for different current driving modes of the vehicle, such as series mode, parallel mode and mode switching, instead of using a single misfire diagnosis threshold value to judge the current misfire signal, so the method can more accurately detect whether the engine has a misfire fault and ensure vehicle driving safety.

[0036] It can be understood that the engine misfire fault detection device, terminal equipment, computer-readable storage medium, computer program product and vehicle provided in the embodiments of the present application have the same beneficial effects as the above-mentioned engine misfire fault detection method, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 A flow chart of an engine misfire fault detection method provided in an embodiment of the present application;

[0039] Figure 2 A flowchart of another engine misfire fault detection method provided by an embodiment of the present application is shown as follows

[0040] Figure 3 A schematic diagram of the structure of an engine misfire fault detection device provided in an embodiment of the present application;

[0041] Figure 4 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0043] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0044] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0045] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0046] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0047] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" means "two or more".

[0048] The engine misfire fault detection method provided by the embodiment of the present application can be executed by a processor of a terminal device when running a corresponding computer program. The terminal device can be an engine management system (Engine Management System, EMS).

[0049] Figure 1 This is a flow chart of an engine misfire fault detection method provided in an embodiment of the present application. For ease of explanation, only the part related to the present embodiment is shown. The method provided in the present embodiment includes the following steps:

[0050] S100: Determine the current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode, and a mode switching mode.

[0051] It should be noted that the vehicle in this embodiment refers to a hybrid electric vehicle, which includes three driving modes: EV (Electric Vehicle) mode, series mode and parallel mode. The series mode refers to a driving mode in which the engine does not directly drive the wheels, but acts as a generator to charge the battery or directly provide power to the motor; the parallel mode refers to a driving mode in which the engine and the motor drive the vehicle at the same time to provide the vehicle with maximum power.

[0052] Among them, the current driving mode refers to the driving mode corresponding to the current operation of the vehicle. The current driving mode can be a series mode, a parallel mode or a mode switching; the mode switching includes the process of the engine switching from a series mode to a parallel mode, or from a parallel mode to a series mode.

[0053] In a specific embodiment, the current driving mode of the vehicle may be determined by identifying a driving mode signal (COMM_HybridMODE) on a CAN (Controller Area Network) system. This embodiment does not limit the specific method for determining the current driving mode of the vehicle.

[0054] S200: Acquire a misfire diagnosis threshold corresponding to the current driving mode.

[0055] The misfire diagnosis threshold refers to a critical value used to determine whether a misfire occurs in a misfire signal.

[0056] In this embodiment, a corresponding misfire diagnosis threshold calibration table may be pre-set for different driving modes; the misfire diagnosis threshold calibration table stores misfire diagnosis thresholds corresponding to different combinations of crankshaft speeds and engine loads. After the current driving mode is determined, the corresponding misfire diagnosis threshold calibration table is determined according to the current driving mode, and then the misfire diagnosis threshold corresponding to the current crankshaft speed and the current engine load is searched from the determined misfire diagnosis threshold calibration table, that is, the misfire diagnosis threshold corresponding to the current driving mode is obtained.

[0057] Table 2 below is a misfire diagnosis threshold calibration table provided in an embodiment of the present application; in Table 2, VRPM represents the crankshaft speed (engine speed), and LOD (Load on Demand) represents the engine load; for different crankshaft speeds and engine loads, misfire diagnosis thresholds corresponding to the series mode and the parallel mode are set respectively.

[0058] Table 2 Misfire diagnosis threshold calibration table

[0059]

[0060]

[0061] It should also be noted that a corresponding misfire diagnostic threshold calibration table may be added only for the series mode, while the parallel mode uses the original misfire diagnostic threshold calibration table; or a corresponding misfire diagnostic threshold calibration table may be added only for the parallel mode, while the series mode uses the original misfire diagnostic threshold calibration table.

[0062] In addition, a functional relationship between the crankshaft speed, the engine load and the misfire diagnosis threshold value may be set in advance for each driving mode. After the current driving mode is determined, the corresponding functional relationship is determined according to the current driving mode, and then the current crankshaft speed and the current engine load are input into the determined functional relationship to calculate the misfire diagnosis threshold value, that is, to obtain the misfire diagnosis threshold value corresponding to the current driving mode.

[0063] In this embodiment, if the current driving mode is in mode switching, the misfire diagnosis threshold corresponding to the current driving mode is the misfire diagnosis threshold corresponding to the driving mode before the mode switching.

[0064] S300: Determine a current misfire signal according to a current crankshaft speed of the engine.

[0065] Among them, the engine crankshaft speed is also the engine speed, which refers to the number of rotations of the engine crankshaft per minute, and the unit is RPM (Revolutions Per Minute).

[0066] In practical applications, the current misfire signal can be determined based on the engine type, current crankshaft speed, and engine load of the engine. The engine type includes two-stroke engines, four-stroke engines, etc. The engine load refers to the load condition of the engine when it is working, which is usually related to the throttle opening, crankshaft speed, and torque output.

[0067] S400: Determine whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold.

[0068] Specifically, after determining the current misfire signal and the misfire diagnosis threshold, the current misfire signal is compared with the misfire diagnosis threshold. If the current misfire signal is greater than the misfire diagnosis threshold, it is determined that the engine has a misfire fault; otherwise, it is determined that the engine does not have a misfire fault.

[0069] In another embodiment, a misfire failure count may also be set. After determining that the current misfire signal is greater than a misfire diagnosis threshold, the misfire failure count is updated. When the misfire failure count is greater than or equal to a preset count threshold, it is determined that the engine has a misfire fault; otherwise, it is determined that the engine does not have a misfire fault and the engine misfire fault detection continues.

[0070] The embodiment of the present application provides an engine misfire fault detection method, which determines a corresponding misfire diagnosis threshold value according to the current driving mode of the vehicle, and after determining the current misfire signal according to the current crankshaft speed of the engine, determines whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold value; because the motor will adjust and correct the crankshaft speed and load to different degrees for different driving modes, thereby affecting the current misfire signal of the engine; the method determines the corresponding misfire diagnosis threshold value for different current driving modes of the vehicle, such as series mode, parallel mode and mode switching, instead of using a single misfire diagnosis threshold value to judge the current misfire signal, so the method can more accurately detect whether the engine has a misfire fault and ensure vehicle driving safety.

[0071] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. Specifically, in this embodiment, determining whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold includes:

[0072] If the current misfire signal is greater than the misfire diagnosis threshold, the misfire failure count is updated;

[0073] If the misfire failure count is greater than or equal to the preset count threshold, it is determined that the engine has a misfire fault.

[0074] Specifically, the misfire failure count is preset, and the misfire failure count is initialized to 0; after determining the current misfire signal, the current misfire signal is compared with the misfire diagnosis threshold; if the current misfire signal is greater than the misfire diagnosis threshold, indicating that a misfire is currently occurring, the misfire failure count is controlled to increase by 1, and it is determined whether the updated misfire failure count is greater than or equal to the preset count threshold; if the current misfire signal is less than or equal to the misfire diagnosis threshold, it is determined that no misfire is currently occurring, and therefore the misfire failure count does not need to be updated. If the updated misfire failure count is less than the preset count threshold, it indicates that the condition for determining that the engine has a misfire fault has not yet been met, and therefore the step of determining the current driving mode of the vehicle is continued, that is, the engine misfire fault detection is continued; if the updated misfire failure count is greater than or equal to the preset count threshold, it indicates that the condition for determining that the engine has a misfire fault has been met, and therefore the engine has been determined to have a misfire fault.

[0075] In this embodiment, the preset count threshold can be determined according to the maximum limit of the misfire phenomenon allowed in the engine cycle. For example, assuming that the maximum number of misfire phenomena allowed in 100 engine cycles is 12 times, that is, the preset count threshold corresponding to the engine cycle is 12, the misfire failure count is updated in the engine cycle, and it is determined whether the misfire failure count is greater than 12; if the updated misfire failure count is greater than 12, it indicates that the current engine has a misfire fault; in the next engine cycle, the misfire failure count is initialized.

[0076] It should be noted that this embodiment does not limit the specific value of the preset counting threshold, which can be set according to actual needs.

[0077] According to the method of this embodiment, it is possible to avoid misjudging the presence of an engine misfire fault based on a single current misfire signal, that is, to improve the accuracy of engine misfire fault detection.

[0078] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. Specifically, in this embodiment, if it is determined that the current driving mode is in mode switching, obtaining the misfire diagnosis threshold corresponding to the current driving mode includes:

[0079] After waiting for a preset time, a misfire diagnosis threshold corresponding to the current driving mode is obtained.

[0080] The mode switching includes the process of the engine switching from the series mode to the parallel mode, or from the parallel mode to the series mode. In this embodiment, the current driving mode of the engine is determined by identifying the driving mode signal (COMM_HybridMODE) on the CAN system. If a change in the driving mode signal is detected, that is, the current driving mode of the engine is in the mode switching, it is not clear how to obtain the misfire diagnosis threshold, and directly calculating the current misfire signal and performing misfire fault determination may lead to inaccurate detection results.

[0081] Therefore, the control of this embodiment does not execute the steps of obtaining the misfire diagnosis threshold and calculating the current misfire signal at this time, but executes the waiting operation. After the waiting time reaches the preset time, the steps of obtaining the misfire diagnosis threshold and calculating the current misfire signal are executed, that is, the step of obtaining the misfire diagnosis threshold corresponding to the current driving mode is entered. Among them, the preset time can be calibrated according to actual needs, such as 1s; this embodiment does not limit this.

[0082] In this embodiment, when it is determined that the current driving mode is in mode switching, the steps of obtaining the misfire diagnosis threshold and calculating the current misfire signal are performed after a preset delay, which can improve the accuracy of engine misfire fault detection and avoid false alarms or missed alarms of misfire faults.

[0083] On the basis of the above embodiments, this embodiment further illustrates and optimizes the technical solution. Specifically, in this embodiment, if it is determined that the current driving mode is in mode switching, the method further includes:

[0084] Correcting the misfire diagnosis threshold or current misfire signal;

[0085] Determine whether the engine has a misfire fault based on the current misfire signal and the misfire diagnosis threshold, including:

[0086] It is determined whether the engine has a misfire fault according to the corrected misfire diagnosis threshold or the corrected current misfire signal.

[0087] The mode switching includes the process of the engine switching from the series mode to the parallel mode, or from the parallel mode to the series mode. In this embodiment, the current driving mode of the engine is determined by identifying the driving mode signal (COMM_HybridMODE) on the CAN system. If a change in the driving mode signal is detected, that is, the current driving mode of the engine is in the mode switching, it is not clear how to obtain the misfire diagnosis threshold, and directly calculating the current misfire signal and performing misfire fault determination may lead to inaccurate detection results.

[0088] In this embodiment, if the current driving mode is in mode switching, the misfire diagnosis threshold corresponding to the current driving mode is the misfire diagnosis threshold corresponding to the driving mode before the mode switching. In a specific implementation, the corresponding misfire diagnosis threshold is determined according to the driving mode before the mode switching, and the current misfire signal is determined according to the current crankshaft speed of the engine; then the current misfire signal is corrected to obtain a corrected current misfire signal; and the corrected current misfire signal and the misfire diagnosis threshold are used to determine whether the engine has a misfire fault. Specifically, the current misfire signal can be corrected by multiplying the current misfire signal by a correction coefficient less than 1, which is not limited in this embodiment.

[0089] In another specific implementation, the corresponding misfire diagnosis threshold is determined according to the driving mode before the mode switching, and the current misfire signal is determined according to the current crankshaft speed of the engine; then the misfire diagnosis threshold is corrected to obtain a corrected misfire diagnosis threshold; and the current misfire signal and the corrected misfire diagnosis threshold are used to determine whether the engine has a misfire fault. Specifically, the misfire diagnosis threshold can be corrected by multiplying the misfire diagnosis threshold by a correction coefficient greater than 1, which is not limited in this embodiment.

[0090] According to the method of this embodiment, when the current driving mode of the engine is in mode switching, by correcting the misfire diagnosis threshold or the current misfire signal, it is determined whether the engine has a misfire fault based on the corrected misfire diagnosis threshold or the corrected current misfire signal, thereby improving the accuracy of engine misfire fault detection and avoiding false alarms or missed alarms of misfire faults.

[0091] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. Specifically, in this embodiment, before determining the current driving mode of the vehicle, the method further includes:

[0092] Obtaining operating parameters of the engine and determining whether the operating parameters are within corresponding preset ranges;

[0093] If the operating parameters are within the preset range, the step of determining the current driving mode of the vehicle is entered.

[0094] It should be noted that the operating parameters of the engine must be within the corresponding preset range to ensure that the engine can operate stably under various working conditions and avoid affecting the accuracy of misfire fault detection. In this embodiment, the operating parameters of the engine include crankshaft speed, system voltage, engine water temperature, engine load, fuel level, fuel supply to the cylinder, and intake pressure.

[0095] The crankshaft speed refers to the number of rotations per minute of the engine crankshaft. In this embodiment, the crankshaft speed upper limit ≥ crankshaft speed ≥ crankshaft speed lower limit. The crankshaft speed is obtained by the crankshaft position sensor. If the crankshaft speed is abnormal, the engine control unit cannot receive the crankshaft position signal, and thus cannot control ignition and fuel injection, affecting the normal driving of the vehicle.

[0096] System voltage refers to the voltage level of the engine control system. The preset range of system voltage usually depends on the vehicle's electrical system design.

[0097] The engine water temperature refers to the temperature of the engine coolant, which is usually between 80℃ and 90℃. The engine water temperature can be collected by the water temperature sensor. If the engine water temperature is abnormal, it will affect the control of fuel injection and ignition timing, resulting in increased fuel consumption, unstable idling, and difficulty in acceleration.

[0098] The engine load refers to the load condition of the engine when it is working, which is usually related to the throttle opening, crankshaft speed and torque output. In this embodiment, the engine load is greater than the engine zero torque line threshold. The throttle opening can be collected by the throttle sensor to determine the engine load; if the throttle fails, it will affect the control of fuel injection and ignition timing.

[0099] The fuel level refers to the amount of fuel in the fuel tank. The preset range corresponding to the fuel level is usually determined by the design of the fuel tank and the operating range of the fuel pump.

[0100] The fuel supply to the cylinder must be within the corresponding preset range to ensure that the cylinder can spray fuel normally.

[0101] Intake pressure refers to the external atmospheric pressure received by the engine intake system. The intake pressure is within the preset range to ensure that the engine can normally inhale air and burn. The preset range corresponding to the intake pressure can be determined according to the altitude and weather conditions. Abnormal intake pressure will affect the fuel injection amount and ignition timing of the engine, and may cause problems such as reduced engine power, increased fuel consumption, and excessive emissions. The intake pressure can be obtained through the intake pressure sensor to determine whether the intake pressure is within the corresponding preset range.

[0102] In this embodiment, the step of determining the current driving mode of the vehicle is performed only when it is determined that the various operating parameters of the engine are within the corresponding preset ranges. That is, the various steps of the engine misfire fault detection method are performed only when it is ensured that the vehicle currently has no other faults that affect the engine misfire fault detection, thereby avoiding other faults of the vehicle from affecting the accuracy of the engine misfire fault detection, which can improve the accuracy of the engine misfire fault detection and avoid false alarms or missed alarms of misfire faults.

[0103] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. Specifically, in this embodiment, determining the current misfire signal according to the current crankshaft speed of the engine includes:

[0104] Determine the current segment time according to the current crankshaft speed;

[0105] Get the previous segment time corresponding to the current segment time;

[0106] The current misfire signal is determined based on the current segment time and the previous segment time.

[0107] The segment time refers to the time taken by the crankshaft to rotate through the segment window of a cylinder in one working cycle of the engine. It is understandable that when there is no misfire in the engine, the segment time corresponding to the crankshaft rotating through the segment window should be the same; when a misfire occurs in the engine, the corresponding segment time will be significantly extended. Therefore, the misfire signal can be determined by monitoring the change in the segment time, and then whether the engine has a misfire.

[0108] In this embodiment, the current segment time is determined according to the current crankshaft speed. Specifically, the current segment time is determined according to the segment window, the current crankshaft speed and the number of engine cylinders. Among them, the segment window refers to the angle of the crankshaft in each working cycle of the engine. For each working cycle completed by a four-stroke engine, the crankshaft rotates two circles, that is, it rotates 720°; for each working cycle completed by a two-stroke engine, the crankshaft rotates one circle, that is, it rotates 360°. The segment window of each cylinder is the segment window divided by the number of cylinders of the engine. For example, for a four-cylinder engine, the segment window of each cylinder is 720° / 4=180°.

[0109] In a specific embodiment, the current segment time is calculated as follows:

[0110]

[0111] Among them, n t Indicates the current crankshaft speed, and z indicates the number of cylinders of the engine.

[0112] Assuming the current crankshaft speed is 3000RPM and the number of cylinders in the engine is 4, the current segment time corresponding to each cylinder is

[0113] The previous segment time refers to the segment time at the previous moment corresponding to the current moment. The current segment time is stored after being calculated each time, so the previous segment time corresponding to the current segment time can be directly obtained.

[0114] Specifically, the current misfire signal is determined according to the current segment time and the previous segment time; the current misfire signal (luts) can be calculated by the following formula:

[0115]

[0116] Among them, ts0 represents the previous segment time, and tst represents the current segment time.

[0117] It can be seen that according to the method of this embodiment, the current misfire signal can be determined efficiently and conveniently, thereby improving the efficiency and accuracy of engine misfire fault detection.

[0118] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application are described in detail below in combination with actual application scenarios. Figure 2 The flowchart of another engine misfire fault detection method provided in the embodiment of the present application is shown. Taking a hybrid vehicle (Hybrid Vehicle) as an example, in the embodiment of the present application, the specific steps of an engine misfire fault detection method are as follows:

[0119] When the hybrid vehicle function of the vehicle is turned on, obtaining the operating parameters of the engine and determining whether the operating parameters are within the corresponding preset range;

[0120] If the operating parameters are within the preset range, the current driving mode of the vehicle is determined by identifying the driving mode signal (COMM_HybridMODE) on the CAN (Controller Area Network) system;

[0121] If the current driving mode is the series mode, the misfire judgment steps corresponding to the series mode are executed: obtaining the misfire diagnosis threshold corresponding to the series mode; determining the current misfire signal according to the current crankshaft speed of the engine; if the current misfire signal is greater than the misfire diagnosis threshold, updating the misfire failure count; if the misfire failure count is greater than or equal to the preset count threshold, determining that the engine has a misfire fault.

[0122] If the current driving mode is the parallel mode, the misfire judgment steps corresponding to the parallel mode are executed: obtaining the misfire diagnosis threshold corresponding to the parallel mode; determining the current misfire signal according to the current crankshaft speed of the engine; if the current misfire signal is greater than the misfire diagnosis threshold, updating the misfire failure count; if the misfire failure count is greater than or equal to the preset count threshold, determining that the engine has a misfire fault.

[0123] If the current driving mode is in mode switching, the misfire judgment steps corresponding to the mode switching are executed: determining the corresponding misfire diagnosis threshold according to the driving mode before the mode switching; determining the current misfire signal according to the current crankshaft speed of the engine; correcting the current misfire signal to obtain a corrected current misfire signal; and determining whether the engine has a misfire fault using the corrected current misfire signal and the misfire diagnosis threshold.

[0124] Alternatively, a corresponding misfire diagnosis threshold is determined according to the driving mode before the mode switch, and a current misfire signal is determined according to the current crankshaft speed of the engine; the misfire diagnosis threshold is corrected to obtain a corrected misfire diagnosis threshold; and the current misfire signal and the corrected misfire diagnosis threshold are used to determine whether the engine has a misfire fault.

[0125] The embodiment of the present application provides an engine misfire fault detection method, which determines a corresponding misfire diagnosis threshold value according to the current driving mode of the vehicle, and after determining the current misfire signal according to the current crankshaft speed of the engine, determines whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold value; because the motor will adjust and correct the crankshaft speed and load to different degrees for different driving modes, thereby affecting the current misfire signal of the engine; the method determines the corresponding misfire diagnosis threshold value for different current driving modes of the vehicle, such as series mode, parallel mode and mode switching, instead of using a single misfire diagnosis threshold value to judge the current misfire signal, so the method can more accurately detect whether the engine has a misfire fault and ensure vehicle driving safety.

[0126] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0127] It should be noted that the information collection process (such as face image collection process, fingerprint information collection process, etc.) / feature extraction process involved in this application is performed with the user's knowledge and permission, that is, the information collection process / feature extraction process complies with the requirements of laws and regulations and does not constitute an act that harms the public interest.

[0128] Figure 3 FIG. 1 is a schematic diagram of the structure of an engine misfire fault detection device provided in an embodiment of the present application. Figure 3 As shown, the engine misfire fault detection device of this embodiment includes a mode determination module 310, a threshold acquisition module 320, a signal determination module 330 and a detection module 340; wherein,

[0129] The mode determination module 310 is used to determine the current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode and a mode switching mode;

[0130] A threshold acquisition module 320 is used to acquire a misfire diagnosis threshold corresponding to the current driving mode;

[0131] A signal determination module 330, for determining a current misfire signal according to a current crankshaft speed of the engine;

[0132] The detection module 340 is used to determine whether there is a misfire fault in the engine according to the current misfire signal and the misfire diagnosis threshold.

[0133] An engine misfire fault detection device provided in an embodiment of the present application has the same beneficial effects as the above-mentioned engine misfire fault detection method.

[0134] In one embodiment, the detection module 340 includes:

[0135] A count update submodule, for updating the misfire failure count if the current misfire signal is greater than the misfire diagnosis threshold;

[0136] The fault determination submodule is used to determine that a misfire fault exists in the engine if the misfire failure count is greater than or equal to a preset count threshold.

[0137] In one embodiment, if it is determined that the current driving mode is in mode switching, the threshold acquisition module 320 includes:

[0138] After waiting for a preset time, a misfire diagnosis threshold corresponding to the current driving mode is obtained.

[0139] In one embodiment, if it is determined that the current driving mode is in mode switching, an engine misfire fault detection device further includes:

[0140] A correction module, used for correcting a misfire diagnosis threshold or a current misfire signal;

[0141] The detection module 340 includes:

[0142] The detection submodule is used to determine whether the engine has a misfire fault according to the corrected misfire diagnosis threshold or the corrected current misfire signal.

[0143] In one embodiment, an engine misfire fault detection device further includes:

[0144] The parameter judgment submodule is used to obtain the operating parameters of the engine and determine whether the operating parameters are within the corresponding preset range; if the operating parameters are within the preset range, the mode determination module is called.

[0145] In one embodiment, the signal determination module 330 includes:

[0146] A first determination submodule, used to determine a current segment time according to a current crankshaft speed;

[0147] The second determination submodule is used to obtain the previous segment time corresponding to the current segment time;

[0148] The signal determination submodule is used to determine the current misfire signal according to the current segment time and the previous segment time.

[0149] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0150] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0151] Figure 4 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application. Figure 4 As shown, the terminal device 400 of this embodiment includes a memory 401, a processor 402, and a computer program 403 stored in the memory 401 and executable on the processor 402; when the processor 402 executes the computer program 403, the steps in the above-mentioned engine misfire fault detection method embodiments are implemented; or when the processor 402 executes the computer program 403, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0152] Exemplarily, the computer program 403 may be divided into one or more modules / units, one or more modules / units are stored in the memory 401, and are executed by the processor 402 to implement the method of the embodiment of the present application. One or more modules / units may be a series of computer program instruction segments that can perform specific functions, and the instruction segments are used to describe the execution process of the computer program 403 in the terminal device 400. For example, the computer program 403 may be divided into a mode determination module, a threshold acquisition module, a signal determination module, and a detection module, and the specific functions of each module are as follows:

[0153] A mode determination module is used to determine the current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode and a mode switching mode;

[0154] A threshold acquisition module, used to acquire a misfire diagnosis threshold corresponding to a current driving mode;

[0155] A signal determination module, for determining a current misfire signal according to a current crankshaft speed of the engine;

[0156] The detection module is used to determine whether there is a misfire fault in the engine according to the current misfire signal and the misfire diagnosis threshold.

[0157] In application, the terminal device 400 may be a computing device such as an engine management system (EMS) vehicle controller, a desktop computer, a notebook, a PDA, or a cloud server. The terminal device 400 may include but is not limited to a memory 401 and a processor 402. Those skilled in the art will appreciate that Figure 4 It is only an example of a terminal device and does not constitute a limitation of the terminal device. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device may also include input and output devices, network access devices, buses, etc.; among which, the input and output devices may include cameras, audio acquisition / playback devices, display screens, etc.; the network access device may include a communication module for wireless communication with external devices.

[0158] In applications, the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0159] In applications, the memory can be an internal storage unit of a terminal device, such as a hard disk or memory of the terminal device; it can also be an external storage device of the terminal device, such as a plug-in hard disk equipped on the terminal device, a smart media card (SMC), a secure digital (SD) card, a flash card, etc.; it can also include both the internal storage unit and the external storage device of the terminal device. The memory is used to store operating systems, applications, boot loaders, data, and other programs, such as program codes of computer programs. The memory can also be used to temporarily store data that has been output or is about to be output.

[0160] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0161] The present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of each of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying the computer program code to a terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electric carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk.

[0162] A computer-readable storage medium provided in an embodiment of the present application has the same beneficial effects as the above-mentioned engine misfire fault detection method.

[0163] An embodiment of the present application further provides a computer program product, including a computer program, which can implement the steps in the above-mentioned method embodiments when executed by a processor.

[0164] A computer program product provided in an embodiment of the present application has the same beneficial effects as the above-mentioned engine misfire fault detection method.

[0165] An embodiment of the present application also provides a vehicle, including a vehicle body and a controller, which executes the steps in the above-mentioned method embodiments.

[0166] The vehicle may be any type of vehicle, such as a fuel vehicle, a battery electric vehicle (BEV), and a hybrid vehicle (Hybrid Vehicle), etc. In this embodiment, the vehicle includes a vehicle body and a controller, and the controller can implement the steps of the engine misfire fault detection method in the above embodiment.

[0167] A vehicle provided in an embodiment of the present application has the same beneficial effects as the above-mentioned engine misfire fault detection method.

[0168] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0169] Those of ordinary skill in the art will appreciate that the devices and algorithm steps of each example 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 performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0170] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices, which can be electrical, mechanical or other forms.

[0171] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for detecting engine misfire faults, characterized in that: The method comprises: Determining a current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode, and a mode switching mode; acquiring a misfire diagnosis threshold corresponding to the current driving mode; determining a current misfire signal based on a current crankshaft speed of the engine; It is determined whether a misfire fault exists in the engine according to the current misfire signal and the misfire diagnosis threshold.

2. The method according to claim 1, characterized in that The determining whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold comprises: If the current misfire signal is greater than the misfire diagnosis threshold, updating the misfire failure count; If the misfire failure count is greater than or equal to a preset count threshold, it is determined that a misfire fault exists in the engine.

3. The method according to claim 1, characterized in that If it is determined that the current driving mode is in mode switching, obtaining a misfire diagnosis threshold value corresponding to the current driving mode includes: After waiting for a preset time period, a misfire diagnosis threshold corresponding to the current driving mode is obtained.

4. The method according to claim 1, characterized in that: If it is determined that the current driving mode is in mode switching, the method further includes: modifying the misfire diagnosis threshold or the current misfire signal; The determining whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold comprises: It is determined whether the engine has a misfire fault according to the corrected misfire diagnosis threshold or the corrected current misfire signal.

5. The method according to claim 1, characterized in that Before determining the current driving mode of the vehicle, the method further includes: Acquiring operating parameters of the engine and determining whether the operating parameters are within corresponding preset ranges; If the operating parameter is within the preset range, the step of determining the current driving mode of the vehicle is entered.

6. The method according to any one of claims 1 to 5, characterized in that: Determining the current misfire signal according to the current crankshaft speed of the engine includes: Determine the current segment time according to the current crankshaft speed; Obtain the previous segment time corresponding to the current segment time; A current misfire signal is determined based on the current segment time and the previous segment time.

7. An engine misfire fault detection device, characterized in that: The device comprises: A mode determination module, used to determine a current driving mode of the vehicle; the current driving mode includes a series mode, a parallel mode and a mode switching mode; A threshold acquisition module, used to acquire a misfire diagnosis threshold corresponding to the current driving mode; a signal determination module, configured to determine a current misfire signal according to a current crankshaft speed of the engine; The detection module is used to determine whether the engine has a misfire fault according to the current misfire signal and the misfire diagnosis threshold.

8. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A vehicle, comprising a vehicle body, characterized in that: It also includes a controller, which executes the steps of the method according to any one of claims 1 to 6.

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