Engine Misfire Judgment Method, Device, Vehicle and Storage Medium

Abstract

The present invention provides a method, device, vehicle and storage medium for judging engine misfire, belonging to the technical field of engines. The method includes: obtaining an acoustic emission signal collected by an acoustic emission sensor installed at a specified position of the engine; when it is determined based on the acoustic emission signal that the engine misfires, obtaining the instantaneous rotational speed value of the engine in each cylinder operation cycle; and positioning the cylinder where the engine misfires based on the instantaneous rotational speed value. The present invention can timely and accurately detect engine misfire faults.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and particularly to a method, device, vehicle and storage medium for judging engine misfire. Background Art

[0002] As the power source of an automobile, the working state of the engine not only affects the vehicle performance, but also affects the vehicle energy consumption. Monitoring the working state of the engine to timely detect engine faults is beneficial to giving full play to the engine performance and saving energy.

[0003] Engine misfire is a common engine fault. In the existing technical solutions for judging whether an engine misfires, on the one hand, it is judged by the interval of rotational speed and load signals in the time domain. This method is only a statistical method and there are certain probability problems. On the other hand, misfire is detected based on the fluctuation of the exhaust pressure. However, there are many influencing factors for the exhaust pressure fluctuation. In some working conditions, even if there is no misfire, the exhaust pressure fluctuation is also very intense, and the measurement error of this method is very large.

[0004] It can be seen that the existing technology cannot accurately judge whether the engine misfires, and at the same time cannot determine the cylinder where the engine misfires. Summary of the Invention

[0005] In view of this, it is necessary to provide a method, device, vehicle and storage medium for judging engine misfire to solve the technical problems that the existing technology cannot accurately judge whether the engine misfires and at the same time cannot determine the cylinder where the engine misfires.

[0006] To solve the above technical problems, on the one hand, the present invention provides a method for judging engine misfire, including:

[0007] Obtaining an acoustic emission signal collected by an acoustic emission sensor installed at a specified position of the engine;

[0008] When it is determined that the engine misfires based on the acoustic emission signal, obtaining the instantaneous rotational speed values of the engine in each cylinder operation cycle;

[0009] Locating the cylinder where the engine misfires based on the instantaneous rotational speed values.

[0010] As a possible implementation manner of the present invention, before the step of obtaining the acoustic emission signal collected by the acoustic emission sensor installed at the specified position of the engine, it includes:

[0011] Calculating the first energy value of the acoustic emission signal received by the acoustic emission sensor at each candidate installation position of the engine;

[0012] Calculate the difference between each of the first energy values and the second energy value of the acoustic emission signal at the acoustic emission signal source, and determine the candidate installation position with the smallest difference as the specified position.

[0013] As a possible implementation manner of the present invention, in this implementation manner, before determining that the engine misfires based on the acoustic emission signal, it includes:

[0014] Decompose the acoustic emission signal by using the empirical mode decomposition method to obtain the intrinsic mode function components of the acoustic emission signals corresponding to the cylinders of the engine;

[0015] Calculate the energy values of the acoustic emission signals corresponding to the cylinders in the engine based on the intrinsic mode function components of the acoustic emission signals corresponding to the cylinders of the engine;

[0016] Judge whether the engine misfires based on the energy values of the acoustic emission signals.

[0017] As a possible implementation manner of the present invention, in this implementation manner, judging whether the engine misfires based on the energy values of the acoustic emission signals includes:

[0018] Calculate the total energy value of the acoustic emission signal corresponding to the engine cylinder based on the energy values of the acoustic emission signals corresponding to the cylinders;

[0019] When the total energy value is greater than or equal to a preset energy threshold, it is determined that the engine does not misfire;

[0020] When the total energy value is less than the preset energy threshold, it is determined that the engine misfires.

[0021] As a possible implementation manner of the present invention, in this implementation manner, obtaining the instantaneous speed values of the engine during the operating cycles of the cylinders includes:

[0022] During one engine operating cycle of the engine, obtain the instantaneous speed values of the engine at each sampling angle of the crank of the engine;

[0023] Based on the corresponding relationship between each sampling angle of the crank and the operating cycles of the cylinders of the engine, determine the instantaneous speed values corresponding to the cylinders during their respective cylinder operating cycles.

[0024] As a possible implementation manner of the present invention, in this implementation manner, locating the cylinder where the engine misfires based on the instantaneous speed values includes:

[0025] Calculate the first average value of the instantaneous speed values sampled by each cylinder during its respective cylinder operating cycle;

[0026] Determine the cylinder with the first average value less than the preset instantaneous rotational speed threshold as the misfiring cylinder.

[0027] As a possible implementation manner of the present invention, in this implementation manner, the obtaining of the instantaneous rotational speed values of the engine during the operating cycles of each cylinder includes:

[0028] Calculate a second average value of the instantaneous rotational speed values corresponding to each cylinder during its respective cylinder operating cycle within a preset number of engine operating cycles;

[0029] Use the second average value as the instantaneous rotational speed value corresponding to each cylinder of the engine during its respective cylinder operating cycle.

[0030] On the other hand, the present invention also provides an engine misfire determination device, including:

[0031] A signal acquisition module, configured to acquire the acoustic emission signal collected by the acoustic emission sensor installed at a specified position of the engine;

[0032] A rotational speed acquisition module, when it is determined based on the acoustic emission signal that the engine misfires, acquires the instantaneous rotational speed values of the engine during the operating cycles of each cylinder;

[0033] A misfire determination module, configured to locate the cylinder where the engine misfires based on the instantaneous rotational speed value.

[0034] On the other hand, the present invention also provides a vehicle, including a memory and a processor, wherein,

[0035] The memory is used to store a program;

[0036] The processor is coupled to the memory and is configured to execute the program stored in the memory to implement the steps in the engine misfire determination method in any of the above implementation manners.

[0037] On the other hand, the present invention also provides a computer-readable storage medium, configured to store a computer-readable program or instruction, and when the program or instruction is executed by a processor, it can implement the steps in the engine misfire determination method in any of the above implementation manners.

[0038] The beneficial effects of the present invention are as follows: First, the present invention collects the acoustic emission signal of the acoustic emission source inside the engine through the acoustic emission sensor installed at a specified position inside the engine, and determines whether the engine misfires through this acoustic emission signal, and the judgment of the engine misfire state is relatively accurate. Then, by obtaining the instantaneous rotational speed values of the engine during the operating cycles of each cylinder and judging the cylinder where the engine misfires based on this instantaneous rotational speed value, the faulty cylinder can be accurately located. The present invention can accurately locate the engine misfiring cylinder in a timely manner, which is convenient for the staff to troubleshoot the problem in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0040] Figure 1 It is a schematic flow chart of a method for judging engine misfire provided by an embodiment of the present invention;

[0041] Figure 2 It is a schematic flow chart of a method for determining the installation position of an acoustic emission sensor provided by an embodiment of the present invention;

[0042] Figure 3 It is a schematic installation diagram of an acoustic emission sensor provided by an embodiment of the present invention;

[0043] Figure 4 It is a schematic flow chart of a method for calculating the signal energy value provided by an embodiment of the present invention;

[0044] Figure 5 It is a schematic flow chart of a method for judging whether an engine misfires based on the energy value provided by an embodiment of the present invention;

[0045] Figure 6 It is a schematic flow chart of a method for calculating the instantaneous engine speed value provided by an embodiment of the present invention;

[0046] Figure 7 It is a schematic flow chart of a method for implementing S101 provided by an embodiment of the present invention;

[0047] Figure 8 It is a schematic flow chart of a method for implementing S601 provided by an embodiment of the present invention;

[0048] Figure 9 It is a schematic structural diagram of an engine misfire judgment device provided by an embodiment of the present invention;

[0049] Figure 10 It is a schematic diagram of the mechanism of a vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0051] In the embodiments of the present invention, the descriptions such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Therefore, the technical features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0052] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0053] The present invention provides a method, device, vehicle, and storage medium for judging engine misfire, which will be described separately below.

[0054] Figure 1 is a schematic flowchart of an embodiment of the engine misfire judgment method provided by the present invention, as Figure 1 shown, the engine misfire judgment method includes:

[0055] S101, obtaining an acoustic emission signal collected by an acoustic emission sensor installed at a specified position of the engine;

[0056] S102, when it is determined that the engine misfires based on the acoustic emission signal, obtaining the instantaneous rotational speed values of the engine during the operating cycles of each cylinder;

[0057] S103, positioning the cylinder where the engine misfires based on the instantaneous rotational speed values.

[0058] The engine misfire judgment method provided by the embodiments of the present invention is used to judge whether the engine has a misfire fault. Engine misfire refers to the phenomenon that one or more cylinders do not work, which will directly lead to faults such as poor engine idle, unstable acceleration, increased carbon deposition, etc. The unburned mixture will also be directly discharged into the atmosphere, damaging the three-way catalyst and causing phenomena such as exhaust pipe popping. Therefore, when a misfire fault occurs during engine startup, it is necessary to detect it in time to facilitate early troubleshooting of the fault.

[0059] In an embodiment of the present invention, an acoustic emission source is installed inside the engine. The installation position of the acoustic emission source can be inside the engine and outside the cylinder, and the specific installation position can be determined according to the actual situation. An acoustic emission signal is emitted by the acoustic emission source and received by an acoustic emission sensor installed at a specified position of the engine. The acoustic emission sensor is generally installed on the engine cover inside the engine, and the specific installation position is related to the position of the acoustic emission source inside the engine. How to determine the installation position of the acoustic emission sensor will be described in detail in the subsequent solutions of the present invention.

[0060] In an embodiment of the present invention, when the acoustic emission wave excited by the acoustic emission source in the engine propagates to the outer surface through the cylinder head with a complex structure, complex phenomena such as reflection, refraction, mode conversion, and energy attenuation will occur. According to the attenuation phenomenon of the acoustic emission signal received by the acoustic emission sensor, it can be determined whether misfire occurs in the engine cylinder. When it is determined that misfire occurs in the engine based on the acoustic emission signal, the instantaneous rotational speed value of the engine in each cylinder operation cycle is obtained. The cylinder operation cycle refers to the cycle of the air cylinder working once, including a complete downward stroke (working stroke) and a reset upward stroke (backup stroke). When the engine has multiple cylinders, the multiple cylinders generally operate in a cross manner, and the cylinder operation cycle of each cylinder will not repeat. Therefore, the misfiring cylinder of the engine can be determined by obtaining the instantaneous rotational speed value of the engine in each cylinder operation cycle.

[0061] The engine misfire determination method provided by the present invention obtains the acoustic emission signal collected by the acoustic emission sensor installed at a specified position of the engine, and determines whether misfire occurs in the engine based on the acoustic emission signal. When it is determined that misfire occurs in the engine, the instantaneous rotational speed value of the engine in each cylinder operation cycle is obtained, and the cylinder where misfire occurs in the engine is located based on the instantaneous rotational speed value. The present invention first collects the acoustic emission signal of the acoustic emission source inside the engine through the acoustic emission sensor installed at a specified position inside the engine, and determines whether misfire occurs in the engine through the acoustic emission signal, and the determination of the misfire state of the engine is relatively accurate. Then, by obtaining the instantaneous rotational speed value of the engine in each cylinder operation cycle and determining the cylinder where misfire occurs in the engine based on the instantaneous rotational speed value, the faulty cylinder can be accurately located. The present invention can locate the misfiring cylinder of the engine in a timely and accurate manner, which is convenient for the staff to troubleshoot in time.

[0062] As a possible implementation manner of the present invention, in this implementation manner, as Figure 2 shown, before obtaining the acoustic emission signal collected by the acoustic emission sensor installed at a specified position of the engine, it includes:

[0063] S201, calculating the first energy value of the acoustic emission signal received by the acoustic emission sensor at each candidate installation position of the engine;

[0064] S202. Calculate the difference between each first energy value and the second energy value of the acoustic emission signal at the acoustic emission signal source, and determine the candidate installation position with the smallest difference as the specified position.

[0065] In the embodiment of the present invention, the acoustic emission signal obtained by the acoustic emission sensor on the cylinder head varies greatly relative to the original acoustic emission source signal. Therefore, when actually applying the acoustic emission technology to engine misfire judgment, it is necessary to first consider whether the acoustic emission source signal can be captured by the sensor or whether the signal-to-noise ratio of the captured signal is high, that is, it is necessary to first study the sensitivity of the measurement point (acoustic emission sensor installation position) to different acoustic emission sources. If the energy attenuation of the acoustic emission signal captured by the acoustic emission sensor relative to the acoustic emission source energy is small, the measurement point sensitivity is high; if the attenuation is large, the measurement point sensitivity is low. In order to ensure the accurate identification of cylinder wear by the acoustic emission signal, sensitivity analysis is required.

[0066] In the embodiment of the present invention, when determining the installation position of the acoustic emission sensor, multiple candidate installation positions can be first determined according to the installation position of the acoustic emission source. Generally, the acoustic emission source is installed at the bottom of the engine, and the acoustic emission sensor is installed on the engine cover. By selecting multiple candidate installation positions on the engine cover, the energy difference between the acoustic emission signal collected when the acoustic emission sensor is at each candidate installation position and the acoustic emission signal source is calculated to determine the final installation position of the acoustic emission sensor. For the convenience of description, taking a specific embodiment as an example, as Figure 3 shown, taking a six-cylinder engine as an example, Figure 3 where a, b, c, d, e, f are six cylinders, and S1 is the installation position of the acoustic emission source sensor. The acoustic emission signal received by the sensor S1 can be used as the acoustic emission source signal. S2~S7 are the preselected installation positions of the acoustic emission sensor. The acoustic emission sensor is a PAC Micro 80D type acoustic emission sensor. By selecting the signal of the sensor within a certain time window and using formulas (1) and (2), the attenuation coefficient of each candidate installation position can be calculated:

[0067] (1)

[0068] (2)

[0069] Among them, E is the energy value of the acoustic emission signal collected by the acoustic emission sensor from time to time v is the amplitude of the acoustic emission signal received by the acoustic emission sensor from time to time kx is the attenuation coefficient when the acoustic emission sensor is installed at the x position, is the energy value of the acoustic emission source signal, is the energy value of the acoustic emission signal collected when the acoustic emission sensor is installed at the x position; the attenuation coefficient kx The smaller it is, the more compliant the installation position of the sensor is.

[0070] In the embodiment of the present invention, the optimal installation position of the acoustic emission sensor inside the engine is determined through experiments to ensure the accuracy of the reception of the acoustic emission signal.

[0071] As a possible implementation manner of the present invention, in this implementation manner, as Figure 4 shown, before determining that the engine misfires based on the acoustic emission signal, it includes:

[0072] S401, decomposing the acoustic emission signal by using the empirical mode decomposition method to obtain the intrinsic mode function components of the acoustic emission signals corresponding to the respective cylinders of the engine;

[0073] S402, calculating the energy values of the acoustic emission signals corresponding to the respective cylinders in the engine based on the intrinsic mode function components of the acoustic emission signals corresponding to the respective cylinders of the engine;

[0074] S403, determining whether the engine misfires based on the energy value of the acoustic emission signal.

[0075] In the embodiment of the present invention, when determining whether the engine has a misfire fault, it is necessary to decompose the acoustic emission signal received by the acoustic emission sensor by using the empirical mode decomposition method to determine the intrinsic mode function components of the acoustic emission signal corresponding to each cylinder of the engine, calculate the energy value of the acoustic emission signal corresponding to each cylinder based on the intrinsic mode function component of each cylinder, and then determine whether the engine has a misfire fault based on the total energy value.

[0076] In the embodiment of the present invention, the acoustic emission information received by the acoustic emission sensor is subjected to empirical mode decomposition to obtain the intrinsic mode function components corresponding to each cylinder of the engine. The energy value of the acoustic emission signal corresponding to each cylinder can be calculated by using formula (3):

[0077] (3)

[0078] Wherein, is the energy value of the acoustic emission signal corresponding to the cylinder i , the acoustic emission signal segment corresponding to the cylinder i is the acoustic emission signal received by the acoustic emission sensor from the moment to the moment , is the intrinsic mode function component corresponding to the cylinder i .

[0079] In the embodiment of the present invention, the acoustic emission signal is processed by the empirical mode decomposition method, and then the energy value of the acoustic emission signal of each cylinder of the engine is calculated, and whether the engine has a misfire fault is determined based on the energy value of the emission signal, and the misfire of the engine can be accurately judged.

[0080] As a possible implementation manner of the present invention, in this implementation manner, as Figure 5 shown, judging whether the engine misfires based on the energy value of the acoustic emission signal includes:

[0081] S501, calculating the total energy value of the acoustic emission signal corresponding to the engine cylinder based on the energy value of the acoustic emission signal corresponding to each cylinder;

[0082] S502, when the total energy value is greater than or equal to a preset energy threshold, determining that the engine does not misfire;

[0083] S503, when the total energy value is less than the preset energy threshold, determining that the engine misfires.

[0084] In the embodiment of the present invention, after calculating the energy value of the acoustic emission signal corresponding to each cylinder, the energy values of the acoustic emission signals corresponding to each cylinder are summed to determine the total energy value of the acoustic emission signal, and then based on the magnitude relationship between the total energy value and the preset energy threshold, it is judged whether the engine has a misfire fault. Specifically, when calculating the total energy value of the acoustic emission signal, the total energy value vector of the acoustic emission signal is constructed using formula (4):

[0085] (4)

[0086] Where T is the total energy value vector of the emission signal, is the energy value of the acoustic emission signal corresponding to the n th cylinder.

[0087] Further, the vector T is normalized using formula (5), and then the total energy value of the acoustic emission signal is determined:

[0088] (5)

[0089] Where E is the total energy value of the acoustic emission signal, and whether the engine has a misfire fault can be judged through the total energy value of the acoustic emission signal. Specifically, when the total energy value of the acoustic emission signal is greater than or equal to the preset energy threshold, it is determined that the engine does not misfire; when the total energy value of the acoustic emission signal is less than the preset energy threshold, it is determined that the engine misfires.

[0090] In the embodiment of the present invention, by calculating the magnitude relationship between the total energy value of the acoustic emission signal corresponding to each cylinder and the preset energy threshold, it is judged whether the engine has a misfire fault, and the misfire of the engine can be found in a timely and accurate manner.

[0091] As a possible implementation manner of the present invention, in this implementation manner, as Figure 6 shown, obtaining the instantaneous rotational speed value of the engine during the operating cycle of each cylinder includes:

[0092] S601, within one engine operating cycle of the engine, obtaining the instantaneous rotational speed value of the engine at each sampling angle of the crank of the engine;

[0093] S602, based on the correspondence between each sampling angle of the crank and the operating cycle of each cylinder of the engine, determining the corresponding instantaneous rotational speed value of each cylinder within its respective cylinder operating cycle.

[0094] In the embodiment of the present invention, since the engine operates reciprocally according to a certain cycle, the instantaneous rotational speed value of the engine can be calculated in sub - cycles. For the sub - cycle method of the engine, the engine cam signal can be collected and processed in sub - cycles to obtain the operating cycle of the engine. Specifically, taking a 60 - tooth - missing - 1 - tooth cam as an example, when the cam is running, the cam signal is collected simultaneously. The difference algorithm is used to find the rising edge of the cam signal, calculate the time interval of the rising edge, find the tooth - missing position, and use the cam signal moment at the tooth - missing position as the sub - cycle signal; among them, the rising edge is determined by calculating the amplitude difference between the cam signal at each sampling moment and its adjacent sampling moment. When the amplitude difference is greater than the preset value, it indicates that the sampling moment is the rising edge of the cam signal; when calculating the tooth - missing signal, by calculating the interval duration between the sampling moment and its adjacent sampling moment of the cam signal, when the interval duration is greater than the preset duration, it indicates that the sampling moment is the tooth - missing signal moment. Based on the above method, the engine operating cycle can be segmented to facilitate obtaining the engine instantaneous rotational speed corresponding to each crank angle in sub - cycles.

[0095] In the embodiment of the present invention, obtaining the engine instantaneous rotational speed value requires processing the crank signal in sub - cycles. For the crank signal, the principle of its sub - cycle method is the same as that of the aforementioned cam signal's sub - cycle method, and will not be elaborated here. After the crank signal is processed in sub - cycles, the engine instantaneous rotational speed can be calculated by formula (6):

[0096] (6)

[0097] Wherein, n is the engine instantaneous rotational speed value, Z is the number of teeth of the engine flywheel, T is the counting period of the counting clock, K is the interval duration between adjacent sampling points of the crank signal.

[0098] Based on the above formula (6), for a complete engine operation cycle, different crank angles correspond to different cylinders of the engine doing work. Therefore, it is possible to determine whether the corresponding cylinder misfires according to the instantaneous rotational speed value of the engine at different sampled crank angles. Generally, the instantaneous rotational speed value corresponding to the misfiring cylinder will decrease significantly.

[0099] In the embodiment of the present invention, by obtaining the instantaneous rotational speed of the engine when the engine crank is at different sampled crank angles in different cycles, and determining whether the cylinder corresponding to the sampled crank angle misfires, the misfiring cylinder of the engine can be accurately located.

[0100] As a possible implementation manner of the present invention, in this implementation manner, as Figure 7 shown, S103 includes:

[0101] S701, calculating the first average value of the instantaneous rotational speed values sampled within the respective cylinder operation cycles of each cylinder;

[0102] S702, determining the cylinders with the first average value less than the preset instantaneous rotational speed threshold as misfiring cylinders.

[0103] In the embodiment of the present invention, based on the crank angle, the operation cycles of each cylinder of the engine can be determined. For example, for a six-cylinder engine, the operation cycle of one cylinder is that the crank rotates 120 degrees, that is, the crank rotates 720 degrees for one movement cycle of the engine. Taking the operation cycle of cylinder 1 from 0 to 120 as an example, the sampling interval of the crank angle is 6 degrees. Then, within one operation cycle of cylinder 1, a total of 20 engine instantaneous rotational speed values are collected. By averaging these 20 engine instantaneous rotational speed values, the corresponding instantaneous rotational speed value of cylinder 1 can be obtained. Then, based on the magnitude relationship between this instantaneous rotational speed value and the preset instantaneous rotational speed threshold, it is determined whether cylinder 1 has a misfiring fault.

[0104] In the embodiment of the present invention, by averaging the engine instantaneous rotational speed values collected within one operation cycle of the cylinder, the corresponding engine instantaneous rotational speed value of the cylinder is obtained, and based on the magnitude relationship between this instantaneous rotational speed value and the preset instantaneous rotational speed threshold, it is determined whether the cylinder misfires, which can accurately judge the misfiring cylinder.

[0105] As a possible implementation manner of the present invention, in this implementation manner, as Figure 8 shown, obtaining the instantaneous rotational speed values of the engine within the operation cycles of each cylinder includes:

[0106] S801, calculating the second average value of the instantaneous rotational speed values corresponding to each cylinder within their respective cylinder operation cycles within a preset number of engine operation cycles;

[0107] S802, using the second average value as the instantaneous rotational speed value corresponding to each cylinder of the engine within their respective cylinder operation cycles.

[0108] In an embodiment of the present invention, in order to further ensure the accuracy of the instantaneous engine speed value corresponding to the cylinder, the average value of the instantaneous speed values corresponding to each cylinder within its respective cylinder operating cycle during a preset number of engine operating cycles can be calculated, and based on this average value, it is determined whether the cylinder misfires, preventing inaccurate calculations caused by accidental interference.

[0109] In an embodiment of the present invention, generally, the instantaneous speed values within N engine operating cycles are calculated using formula (7):

[0110] (7)

[0111] Wherein, v is the average value of the instantaneous engine speed, N is the number of engine operating cycles, Z is the number of data. Generally, Z the value of is twice the number of teeth of the engine flywheel, j is the i th instantaneous engine speed value within the

[0112] Based on formula (7), the average value of the instantaneous engine speed values corresponding to each cylinder within multiple engine operating cycles can be calculated, providing more accurate calculation data for determining whether the engine misfires.

[0113] In order to better implement the engine misfire determination method in the embodiments of the present invention, correspondingly, based on the engine misfire determination method, as Figure 9 shown, an embodiment of the present invention also provides an engine misfire determination device. The engine misfire determination device 900 includes:

[0114] A signal acquisition module 901, configured to acquire the acoustic emission signal collected by an acoustic emission sensor installed at a specified position of the engine;

[0115] A speed acquisition module 902, configured to acquire the instantaneous speed value of the engine within each cylinder operating cycle when it is determined based on the acoustic emission signal that the engine misfires;

[0116] A misfire determination module 903, configured to locate the cylinder where the engine misfires based on the instantaneous speed value.

[0117] The engine misfire determination device 900 provided in the above embodiment can implement the technical solutions described in the above engine misfire determination method embodiment. The specific implementation principles of the above modules or units can be referred to the corresponding content in the above engine misfire determination method embodiment, and will not be elaborated here.

[0118] In an embodiment of the present invention, an acoustic emission signal collected by an acoustic emission sensor installed at a specified position of an engine is obtained. Based on the acoustic emission signal, it is determined whether the engine misfires. When it is determined that the engine misfires, the instantaneous rotational speed values of the engine in each cylinder operating cycle are obtained, and the cylinder where the engine misfires is located based on the instantaneous rotational speed values. First, the present invention collects the acoustic emission signal of the acoustic emission source inside the engine through the acoustic emission sensor installed at a specified position inside the engine, and determines whether the engine misfires through the acoustic emission signal, which is relatively accurate in judging the misfiring state of the engine. Then, by obtaining the instantaneous rotational speed values of the engine in each cylinder operating cycle and judging the cylinder where the engine misfires based on the instantaneous rotational speed values, the faulty cylinder can be accurately located. The present invention can timely and accurately locate the misfiring cylinder of the engine, facilitating the staff to troubleshoot in time.

[0119] As Figure 10 shown, the present invention also correspondingly provides a vehicle 1000. The vehicle 1000 includes a processor 1001, a memory 1002, and a display 1003. Figure 10 Only some components of the vehicle 1000 are shown, but it should be understood that it is not required to implement all the shown components, and more or fewer components can be alternatively implemented.

[0120] In some embodiments, the processor 1001 can be a central processing unit (CPU), a microprocessor, or other data processing chips, and is used to run the program code stored in the memory 1002 or process data, such as the engine misfire judgment method in the present invention.

[0121] In some embodiments, the processor 1001 can be a single server or a server group. The server group can be centralized or distributed. In some embodiments, the processor 1001 can be local or remote. In some embodiments, the processor 1001 can be implemented on a cloud platform. In one embodiment, the cloud platform can include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination of the above.

[0122] In some embodiments, the memory 1002 can be an internal storage unit of the electronic device on the vehicle 1000, such as the hard disk or memory of the electronic device inside the vehicle 1000. In some other embodiments, the memory 1002 can also be an external storage device of the vehicle 1000, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc.

[0123] Further, the memory 1002 may also include both the internal storage unit of the vehicle 1000 and an external storage device. The memory 1002 is used to store the application software installed in the vehicle 1000 and various types of data.

[0124] In some embodiments, the display 1003 may be an LED display, a liquid crystal display, a touch liquid crystal display, and an OLED (Organic Light-Emitting Diode) toucher, etc. The display 1003 is used to display the information of the vehicle 1000 and to display a visual user interface. The components 1001 - 1003 of the vehicle 1000 communicate with each other through the system bus.

[0125] In one embodiment, when the processor 1001 executes the engine misfire judgment program in the memory 1002, the following steps can be implemented:

[0126] Obtain the acoustic emission signal collected by the acoustic emission sensor installed at a specified position of the engine;

[0127] When it is determined based on the acoustic emission signal that the engine has misfired, obtain the instantaneous rotational speed value of the engine during each cylinder operation cycle;

[0128] Locate the cylinder where the engine has misfired based on the instantaneous rotational speed value.

[0129] It should be understood that when the processor 1001 executes the engine misfire judgment program in the memory 1002, in addition to the above functions, other functions can also be implemented. For specific details, reference can be made to the description of the corresponding method embodiments above.

[0130] Correspondingly, an embodiment of the present invention also provides a computer-readable storage medium. The computer-readable storage medium is used to store computer-readable programs or instructions. When the programs or instructions are executed by the processor, the steps or functions in the engine misfire judgment method provided by the above method embodiments can be implemented.

[0131] Those skilled in the art can understand that all or part of the processes of implementing the above method embodiments can be completed by instructing relevant hardware (such as a processor, a controller, etc.) through a computer program. The computer program can be stored in a computer-readable storage medium. Among them, the computer-readable storage medium is a magnetic disk, an optical disk, a read-only memory, or a random access memory, etc.

[0132] The above has introduced in detail the method, device, vehicle and storage medium for judging engine misfire provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for determining engine misfire, characterized in that: include: Acquire the acoustic emission signal collected by the acoustic emission sensor installed at the specified position of the engine; When it is determined based on the acoustic emission signal that the engine misfires, the instantaneous speed value of the engine in each cylinder operation cycle is obtained, wherein the obtaining of the instantaneous speed value of the engine in each cylinder operation cycle includes: Acquire the instantaneous speed value of the engine at each sampling rotation angle of the crank of the engine during an engine operation cycle of the engine; determine the instantaneous speed value corresponding to each cylinder during its respective cylinder operation cycle based on the corresponding relationship between each sampling rotation angle of the crank and the operation cycle of each cylinder of the engine; A first average value of instantaneous speed values ​​sampled in each cylinder during its respective cylinder operation cycle is calculated; and a cylinder whose first average value is less than a preset instantaneous speed threshold is determined as a misfiring cylinder.

2. The engine misfire determination method according to claim 1, characterized in that: Before obtaining the acoustic emission signal collected by the acoustic emission sensor installed at the specified position of the engine, it includes: Calculating a first energy value of an acoustic emission signal received by the acoustic emission sensor at each candidate installation position of the engine; The difference between each of the first energy values ​​and the second energy value of the acoustic emission signal at the acoustic emission signal source is calculated, and the candidate installation position with the smallest difference is determined as the designated position.

3. The engine misfire determination method according to claim 1, characterized in that: Before determining that the engine misfires based on the acoustic emission signal, the method includes: Decomposing the acoustic emission signal by using an empirical mode decomposition method to obtain an intrinsic mode function component of the acoustic emission signal corresponding to each cylinder of the engine; Calculating the energy value of the acoustic emission signal corresponding to each cylinder in the engine based on the intrinsic mode function component of the acoustic emission signal corresponding to each cylinder of the engine; It is determined whether the engine misfires based on the acoustic emission signal energy value.

4. The engine misfire determination method according to claim 3, characterized in that: The determining whether the engine has misfired based on the acoustic emission signal energy value comprises: Calculating the total energy value of the acoustic emission signal corresponding to the engine cylinder based on the energy value of the acoustic emission signal corresponding to each cylinder; When the total energy value is greater than or equal to a preset energy threshold, determining that the engine is not misfiring; When the total energy value is less than a preset energy threshold, it is determined that the engine misfires.

5. The engine misfire determination method according to claim 1, characterized in that: The step of obtaining the instantaneous speed value of the engine in each cylinder operation cycle further includes: Calculating a second average value of the instantaneous rotational speed value of each cylinder corresponding to each cylinder operation cycle within a preset number of engine operation cycles; The second average value is used as the instantaneous speed value corresponding to each cylinder of the engine in each cylinder operation cycle.

6. An engine misfire judgment device, characterized in that: include: A signal acquisition module is used to acquire an acoustic emission signal collected by an acoustic emission sensor installed at a specified position of the engine; A speed acquisition module, when it is determined based on the acoustic emission signal that the engine misfires, acquires the instantaneous speed value of the engine in each cylinder operation cycle, wherein acquiring the instantaneous speed value of the engine in each cylinder operation cycle includes: Acquire the instantaneous speed value of the engine at each sampling rotation angle of the crank of the engine during an engine operation cycle of the engine; determine the instantaneous speed value corresponding to each cylinder during its respective cylinder operation cycle based on the corresponding relationship between each sampling rotation angle of the crank and the operation cycle of each cylinder of the engine; The misfire judgment module is used to calculate a first average value of the instantaneous speed values ​​sampled by each cylinder during its respective cylinder operation cycle; and determine a cylinder whose first average value is less than a preset instantaneous speed threshold as a misfire cylinder.

7. A vehicle, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the engine misfire judgment method as described in any one of claims 1 to 5 above.

8. A computer-readable storage medium, characterized in that: Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps of the engine misfire judgment method described in any one of claims 1 to 5.

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