Degradation method, degradation device and vehicle for engine misfire

Abstract

The application provides a misfire degradation method, a degradation device and a vehicle, and the method comprises the following steps: obtaining a target time length by querying a first mapping relationship; if a first misfire rate is greater than a first threshold value and lasts for the target time length; if a first target voltage is less than a second threshold value, sequentially igniting according to a second target voltage to obtain a second misfire rate, and determining the second target voltage with the minimum second misfire rate as an ignition voltage; if a difference between the second misfire rate and the first misfire rate is less than a fourth threshold value, igniting according to multiple second set values to obtain a third misfire rate, and determining the second set value with the minimum third misfire rate as a target air-fuel ratio; if a difference between the third misfire rate and the first misfire rate within the target time length is less than a sixth threshold value and / or the first misfire rate is greater than a seventh threshold value, adjusting a first power-on time of each cylinder of the engine and / or limiting the torque of the engine. The method solves the problem that there is a lack of adjustment measures in the prior art when the misfire rate does not reach the fault threshold value.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, and more specifically, to a method, device, computer-readable storage medium, and vehicle for degrading engine misfire. Background Technology

[0002] Engine misfire refers to a malfunction in an internal combustion engine where the air-fuel mixture fails to ignite and burn in one or more cylinders. There are many causes of engine misfire, primarily including spark plug failure, insufficient ignition duration, fuel injector malfunction, an excessively lean or rich air-fuel mixture, valve train malfunction, poor cylinder sealing, and insufficient compression pressure. Misfire causes the air-fuel mixture in a certain cycle to partially or completely fail to burn, resulting in decreased power output, increased fuel consumption, and excessive emissions, especially a sharp increase in HC (carbon dioxide) content in the exhaust gas. This can lead to overheating or poisoning and damage to the three-way catalytic converter, creating a vicious cycle.

[0003] In current technologies, the degradation measures after a fire are relatively simple. When the fire rate reaches the fault threshold, a fire fault is reported, and torque is immediately limited. When the fire rate has not reached the fault threshold, there are no adjustment measures, resulting in speed fluctuations and poor economy and comfort. Summary of the Invention

[0004] The main objective of this application is to provide a method, device, computer-readable storage medium, and vehicle for downgrading engine misfire, so as to at least solve the problem in the prior art that when the misfire rate does not reach the fault threshold, there are no adjustment measures, resulting in engine speed fluctuations, poor economy, and poor comfort.

[0005] To achieve the above objectives, according to one aspect of this application, a method for degrading engine misfire is provided, comprising: obtaining a first misfire rate and querying a first mapping relationship based on the first misfire rate to obtain a target duration; when the first misfire rate is greater than a first threshold and the duration is greater than the target duration, obtaining a first target voltage, wherein the first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration for which the first misfire rate does not cause damage to the catalyst in the engine, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine; when the first target voltage is less than a second threshold, sequentially controlling the ignition coil to ignite based on a plurality of second target voltages and obtaining the corresponding real-time misfire rate to obtain a plurality of second misfire rates, and determining the second target voltage corresponding to the smallest second misfire rate as the ignition coil voltage. The second target voltage is greater than the second target voltage and the difference between the second target voltage and the first target voltage is less than a third threshold. When the difference between the second misfire rate and the first misfire rate is less than a fourth threshold, a first set value is obtained. The engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates. The second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine. The difference between the second set value and the first set value is less than a fifth threshold. When the difference between the third misfire rate and the first misfire rate is less than a sixth threshold and / or the first misfire rate is greater than a seventh threshold, the first ignition time of each cylinder of the engine is adjusted and / or the engine torque is limited. The seventh threshold is greater than the first threshold.

[0006] Optionally, after obtaining the target duration by querying the first mapping relationship based on the first misfire rate, the method further includes: obtaining a target rotational speed and a target load; querying a second mapping relationship based on the target rotational speed and the target load to obtain a target coefficient, wherein the target rotational speed is the rotational speed of the engine, the load is the load of the engine, the target coefficient is a correction coefficient for the target duration, and the second mapping relationship is a mapping relationship between the rotational speed, the load, and the correction coefficient; and calculating the product of the target coefficient and the target duration to obtain the corrected duration.

[0007] Optionally, controlling the ignition coil to ignite sequentially according to multiple second target voltages includes: obtaining a first interval length; determining a first target interval based on the first interval length and the first target voltage, wherein the minimum value of the first target interval is the first target voltage; randomly selecting multiple voltages in the first target interval to obtain multiple second target voltages; arranging the second target voltages from smallest to largest; determining the corresponding energizing time of the ignition coil based on each second target voltage to obtain multiple second energizing times; and controlling the ignition coil to ignite sequentially according to the second energizing times from smallest to largest.

[0008] Optionally, after determining the second target voltage corresponding to the minimum second misfire rate as the ignition voltage of the ignition coil, the method further includes: obtaining a target number of times the ignition voltage is updated under different target speeds and target loads, and determining that the ignition coil is faulty if the target number is greater than an eighth threshold.

[0009] Optionally, controlling the engine to ignite according to multiple second set values ​​includes: obtaining a second interval length; determining a second target interval and a third target interval based on the second interval length and the first set value, wherein the minimum value of the second target interval is the first set value and the maximum value of the third target interval is the first set value; randomly selecting multiple air-fuel ratios in the second target interval to obtain multiple third set values; controlling the engine to ignite according to the third set values ​​in ascending order, and obtaining the corresponding real-time misfire rate to obtain a fourth misfire rate; when the difference between the fourth misfire rate and the first misfire rate is less than a ninth threshold, randomly selecting multiple air-fuel ratios in the third target interval to obtain the second set values; and controlling the engine to ignite according to the second set values ​​in ascending order.

[0010] Optionally, adjusting the first energizing time of each cylinder of the engine and / or limiting the torque of the engine includes: obtaining the injection type of the engine; limiting the torque of the engine when the injection type is single-point injection; determining the first cylinder and the second cylinder when the injection type is multi-point injection; controlling the injection of the first cylinder to be cut off when the injection of the first cylinder is less than the tenth threshold, wherein the first cylinder is a misfired cylinder and the second cylinder is a non-misfired cylinder; and adjusting the first energizing time of the second cylinder according to the target load to keep the target load constant.

[0011] Optionally, after adjusting the first energizing time of the second cylinder according to the target load, the method further includes: limiting the torque of the engine if the first energizing time is greater than an eleventh threshold, and adjusting the first energizing time of the second cylinder according to the target load after torque limiting.

[0012] According to another aspect of this application, a degrading device for engine misfire is provided. The device includes: a first acquisition unit, configured to acquire a first misfire rate and query a first mapping relationship based on the first misfire rate to obtain a target duration; and, when the first misfire rate is greater than a first threshold and the duration is greater than the target duration, acquire a first target voltage, wherein the first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration for which the first misfire rate does not damage the catalyst in the engine, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine; and a first control unit, configured to, when the first target voltage is less than a second threshold, sequentially control the ignition coil to ignite based on a plurality of second target voltages and acquire the corresponding real-time misfire rate to obtain a plurality of second misfire rates, and determine the second target voltage corresponding to the smallest second misfire rate as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than a third threshold; the second control unit is used to obtain a first set value when the difference between the second misfire rate and the first misfire rate is less than a fourth threshold, control the engine to ignite according to multiple second set values ​​and obtain the corresponding real-time misfire rate to obtain multiple third misfire rates, and determine the second set value with the smallest corresponding third misfire rate as the target air-fuel ratio of the engine, the first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than a fifth threshold; the third control unit is used to adjust the first ignition time of each cylinder of the engine and / or limit the torque of the engine when the difference between the third misfire rate and the first misfire rate is less than a sixth threshold and / or the first misfire rate is greater than a seventh threshold, the seventh threshold being greater than the first threshold.

[0013] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0014] According to another aspect of this application, a vehicle is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of the methods described.

[0015] Applying the technical solution of this application, in the above-mentioned engine misfire degradation method, firstly, a first misfire rate is obtained, and a target duration is obtained by querying a first mapping relationship based on the first misfire rate. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, a first target voltage is obtained. The first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration for which the catalyst in the engine does not cause damage, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine. Then, if the first target voltage is less than a second threshold, the ignition coil is sequentially controlled to ignite based on multiple second target voltages, and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage corresponding to the smallest second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the second target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold. Then, when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained. The engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates. The second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine. The difference between the second set value and the first set value is less than the fifth threshold. Finally, when the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, the first ignition time of each cylinder of the engine is adjusted and / or the engine torque is limited. The seventh threshold is greater than the first threshold. This application sets a first threshold and a seventh threshold. When the misfire rate is greater than the first threshold but less than the seventh threshold, the misfire rate is reduced by sequentially adjusting the voltage of the ignition coil and the air-fuel ratio of the engine. When the misfire rate is greater than the seventh threshold, injection is cut off to the misfired cylinder and / or torque is limited in the engine. This application implements a graded downgrading mechanism for the engine. Compared to the prior art where torque is immediately limited when the misfire rate reaches a fault threshold, this application solves the problem in the prior art where there is no adjustment measure when the misfire rate has not reached the fault threshold, resulting in speed fluctuations and poor fuel economy and comfort. Attached Figure Description

[0016] Figure 1A hardware structure block diagram of a mobile terminal for an engine misfire degradation method provided in an embodiment of this application is shown.

[0017] Figure 2 A schematic flowchart of a method for degrading engine misfire according to an embodiment of this application is shown.

[0018] Figure 3 A schematic flowchart of a method for adjusting the ignition energy of an ignition coil according to an embodiment of this application is shown.

[0019] Figure 4 A schematic flowchart illustrating a method for adjusting the air-fuel ratio of an engine according to an embodiment of this application is shown:

[0020] Figure 5 A schematic flowchart of a specific engine misfire degradation method according to an embodiment of this application is shown;

[0021] Figure 6 A structural block diagram of an engine misfire degradation device provided according to an embodiment of this application is shown.

[0022] The above figures include the following reference numerals:

[0023] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] As described in the background section, the existing degrading measures for engine misfire are relatively simple. When the misfire rate does not reach the fault reporting threshold, there is a lack of adjustment measures. In order to solve the problem that there are no adjustment measures when the misfire rate does not reach the fault threshold, resulting in speed fluctuations and poor economy and comfort, the embodiments of this application provide an engine misfire degrading method, a degrading device, a computer-readable storage medium, and a vehicle.

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] The methods and embodiments provided in this application can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for an engine misfire degradation method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0030] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0031] This embodiment provides a degradation method for an engine misfire that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0032] Figure 2 This is a flowchart of a method for degrading engine misfire according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0033] Step S201: Obtain a first misfire rate and query a first mapping relationship based on the first misfire rate to obtain a target duration. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, obtain a first target voltage. The first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration during which the catalyst in the engine will not be damaged, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine.

[0034] Specifically, in the event of an engine misfire, the current real-time misfire rate is obtained to obtain the aforementioned first misfire rate. If the first misfire rate exceeds a first threshold, it is determined that the first misfire rate affects the stability of engine operation. To avoid damage to the catalyst caused by misfire rate fluctuations during engine control, this application sets a maximum time limit for adjusting the engine at different misfire rates without damaging the catalyst, resulting in the aforementioned target duration. Engine control is then necessary to reduce the misfire rate. Because the misfire rate and the catalyst temperature rise are linear or approximately related, in one embodiment, a correspondence between the misfire rate and the target duration is constructed to obtain the aforementioned first mapping relationship.

[0035] Step S202: When the first target voltage is less than the second threshold, the ignition coil is controlled to ignite according to the multiple second target voltages and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold.

[0036] Specifically, as mileage increases, the spark plug gap may widen, leading to a higher ignition energy required for ignition. Since the engine's set ignition voltage may not meet the increased ignition energy, misfire may occur. Therefore, in one embodiment, this application sets up a method to obtain the aforementioned first target voltage by acquiring the voltage of the secondary ignition coil. If the first target voltage is less than a first threshold, it is determined that there is a possibility of misfire due to low ignition energy. At this time, the first target voltage is increased to obtain multiple second target voltages, and ignition is attempted sequentially to obtain the corresponding misfire rate. If the misfire rate decreases, the second target voltage with the lowest misfire rate is determined as the updated set ignition voltage for the engine.

[0037] Step S203: When the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates, and the second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold.

[0038] Specifically, during the process of adjusting the engine ignition based on the ignition voltage, the misfire rate does not change significantly. That is, when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, the current air-fuel ratio of the engine is obtained to obtain the first set value. Then, the engine is adjusted within a preset range based on the first set value and ignition is attempted. The corresponding real-time misfire rate is recorded to obtain the third misfire rate. The second set value with the smallest third misfire rate is determined as the air-fuel ratio when the engine is set to ignite, i.e., the target air-fuel ratio.

[0039] Step S204: If the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine, wherein the seventh threshold is greater than the first threshold.

[0040] Specifically, when adjusting the engine's ignition voltage and air-fuel ratio has no significant effect on reducing the engine's ignition rate (i.e., the difference between the third misfire rate and the first misfire rate is less than the sixth threshold within the target time period), and / or the engine misfire rate exceeds the set value (i.e., the first misfire rate is greater than the seventh threshold), the engine's ignition system is determined to be faulty. In the event of an ignition system fault, to ensure normal vehicle operation, this application sets up torque limiting and / or adjusts the energizing time of each cylinder to distribute the output torque of the misfired cylinder to the normal cylinder, ensuring stable vehicle operation before repair.

[0041] In this embodiment, firstly, a first misfire rate is obtained, and a target duration is obtained by querying a first mapping relationship based on the first misfire rate. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, a first target voltage is obtained. The first misfire rate is the engine's real-time misfire rate, the first misfire rate is the maximum duration for which the first misfire rate does not damage the catalyst in the engine, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the engine's ignition coil. Then, if the first target voltage is less than a second threshold, the ignition coil is sequentially controlled to ignite based on multiple second target voltages, and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage. A second target voltage is applied, and the difference between the second target voltage and the first target voltage is less than a third threshold. Then, when the difference between the second misfire rate and the first misfire rate is less than a fourth threshold, a first set value is obtained. Based on multiple second set values, the engine is controlled to ignite, and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates. The second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine. The difference between the second set value and the first set value is less than a fifth threshold. Finally, when the difference between the third misfire rate and the first misfire rate is less than a sixth threshold and / or the first misfire rate is greater than a seventh threshold, the first ignition time of each cylinder of the engine is adjusted, and / or torque is limited in the engine. The seventh threshold is greater than the first threshold. This application sets a first threshold and a seventh threshold. When the misfire rate is greater than the first threshold but less than the seventh threshold, the misfire rate is reduced by sequentially adjusting the voltage of the ignition coil and the air-fuel ratio of the engine. When the misfire rate is greater than the seventh threshold, injection is cut off to the misfired cylinder and / or torque is limited in the engine. This application implements a graded downgrading mechanism for the engine. Compared to the prior art where torque is immediately limited when the misfire rate reaches a fault threshold, this application solves the problem in the prior art where there is no adjustment measure when the misfire rate has not reached the fault threshold, resulting in speed fluctuations and poor fuel economy and comfort.

[0042] To ensure that the catalyst is not damaged, in an optional embodiment, after obtaining the target duration by querying the first mapping relationship based on the first misfire rate, the method further includes:

[0043] Step S301: Obtain the target speed and target load, and obtain the target coefficient by querying the second mapping relationship based on the target speed and target load. The target speed is the speed of the engine, the load is the load of the engine, the target coefficient is the correction coefficient of the target duration, and the second mapping relationship is the mapping relationship between the speed, the load and the correction coefficient.

[0044] Specifically, the engine operates differently under different speeds and loads, thus altering the impact of the misfire rate on the catalyst. Therefore, to ensure no damage to the catalyst, this application calibrates the maximum time at which the misfire rate does not damage the catalyst, determining correction coefficients for different speeds and loads, thus obtaining the aforementioned second mapping relationship. Therefore, by obtaining the real-time speed and load of the engine with the first misfire rate, i.e., obtaining the target speed and target load, the corresponding correction coefficients can be retrieved based on the target load and target speed.

[0045] Step S302: Calculate the product of the above target coefficient and the above target duration to obtain the corrected duration.

[0046] Specifically, the target duration is adjusted based on the target coefficient to obtain the adjusted duration corresponding to the current working condition.

[0047] To reduce the aforementioned first fire failure rate, in one optional implementation, such as Figure 3 As shown, step S202 above includes:

[0048] Step S2021: Obtain the length of the first interval, and determine the first target interval based on the first interval length and the first target voltage. The minimum value of the first target interval is the first target voltage.

[0049] Specifically, there is an upper limit to the voltage adjustment of the ignition coil. The difference between the first target voltage and the upper limit is determined to obtain the length of the first interval. Then, the range of the second target voltage is determined to obtain the first target interval.

[0050] Step S2022: Randomly select multiple voltages in the first target interval to obtain multiple second target voltages;

[0051] Specifically, multiple second target voltages are obtained by randomly selecting voltages within the first target range as adjusted test voltages.

[0052] Step S2023: Arrange the second target voltages from smallest to largest, and determine the energizing time of the corresponding ignition coil according to each second target voltage to obtain multiple second energizing times;

[0053] Specifically, the voltage of the ignition coil is affected by the ignition coil's energizing time. Therefore, this application sets the second target voltage to be arranged from smallest to largest, and calculates the corresponding second energizing time of the ignition coil according to the second target voltage.

[0054] Step S2024: Ignite the ignition coils sequentially according to the second power-on time, from smallest to largest.

[0055] Specifically, the ignition coil is energized sequentially according to the second energizing time to initiate ignition and make an attempt.

[0056] To avoid losses caused by ignition coil failure, in an optional embodiment, after determining the second target voltage corresponding to the minimum second misfire rate as the ignition voltage of the ignition coil, the method further includes:

[0057] Step S401: Obtain the target number of times the ignition voltage is updated under different target speeds and target loads. If the target number is greater than the eighth threshold, determine that the ignition coil is faulty.

[0058] Specifically, the target speed and target load for adjusting the ignition voltage of the ignition coil are recorded. The number of adjustments is determined under the same target speed and target load. If adjustments are made multiple times under the same operating conditions within a short period of time, i.e., if the number of adjustments exceeds the eighth threshold, an ignition coil fault is determined, an alarm is triggered, and the driver is prompted to carry out maintenance.

[0059] To reduce the aforementioned second fire failure rate, in one optional implementation, such as Figure 4 As shown, step S203 above includes:

[0060] Step S2031: Obtain the length of the second interval, and determine the second target interval and the third target interval based on the length of the second interval and the first set value. The minimum value of the second target interval is the first set value, and the maximum value of the third target interval is the first set value.

[0061] Specifically, the air-fuel ratio adjustment of the aforementioned engine has a maximum and a minimum value. The maximum range of air-fuel ratio adjustment is determined based on the difference between the limit value and the aforementioned first preset value, resulting in the aforementioned second interval length. Then, based on the aforementioned second interval length, the interval from which the first preset value is taken upwards is determined to obtain the aforementioned second target interval. Finally, based on the aforementioned second interval length, the interval from which the first preset value is taken downwards is determined to obtain the aforementioned third target interval.

[0062] Step S2032: Randomly select multiple air-fuel ratios within the aforementioned second target range to obtain multiple third set values;

[0063] Specifically, firstly, the air-fuel ratio of the engine is increased, and then multiple air-fuel ratios are randomly selected within the second target range as the test air-fuel ratios to obtain multiple third set values.

[0064] Step S2033: Control the engine to ignite according to the third set value from smallest to largest, and obtain the corresponding real-time misfire rate to obtain the fourth misfire rate;

[0065] Specifically, during the experiment, the air-fuel ratio was increased sequentially and ignition was performed in each ignition cycle, and the corresponding real-time misfire rate was recorded to obtain the aforementioned fourth misfire rate.

[0066] Step S2034: When the difference between the fourth misfire rate and the first misfire rate is less than the ninth threshold, multiple air-fuel ratios are randomly selected in the third target range to obtain the second set value.

[0067] Specifically, when increasing the air-fuel ratio has little effect on controlling and adjusting the engine, that is, when the difference between the fourth misfire rate and the first misfire rate is less than the ninth threshold, the air-fuel ratio of the engine is reduced, and multiple air-fuel ratios are randomly selected in the third space as the test air-fuel ratios to obtain the second set value.

[0068] Step S2035: The engine is ignited sequentially according to the second set value mentioned above, from smallest to largest.

[0069] Specifically, during the experiment, the air-fuel ratio was increased sequentially and ignition was performed in each ignition cycle, and the corresponding real-time misfire rate was recorded to obtain the aforementioned third misfire rate.

[0070] In the event of an ignition coil failure, to ensure stable engine operation, in one optional implementation, step S204 includes:

[0071] Step S2041: Obtain the injection type of the engine; if the injection type is single-point injection, limit the torque of the engine.

[0072] Specifically, engine injection types are divided into single-point injection and multi-point injection. In order to ensure stable engine operation in the event of engine misfire, when the engine injection type is single-point injection, torque is limited to stabilize the engine's operating state.

[0073] Step S2042: When the above-mentioned injection type is multi-point injection, the first cylinder and the second cylinder are determined. When the first cylinder is less than the tenth threshold, the first cylinder is controlled to cut off the injection. The first cylinder is the misfired cylinder and the second cylinder is the non-misfired cylinder.

[0074] Specifically, when the engine uses multi-point injection, the engine cylinders are inspected to identify the cylinder experiencing a misfire, which is designated as the first cylinder, and the cylinders without misfires are designated as the second cylinder. If the number of first cylinders is less than the tenth threshold, it is determined that the first cylinder can be shut down, and the output torque of the first cylinder can be shared by the second cylinder.

[0075] Step S2043: Adjust the first energizing time of the second cylinder according to the target load to keep the target load unchanged.

[0076] Specifically, adjusting the output torque of the second cylinder includes readjusting the load of each second cylinder according to the target load, and then adjusting the energizing time of the cylinder, i.e., adjusting the first energizing time to maintain the target load stable.

[0077] To avoid engine damage, in an optional embodiment, after adjusting the first energizing time of the second cylinder according to the target load, the method further includes:

[0078] Step S501: If the first power-on time is greater than the eleventh threshold, the engine torque is limited, and the first power-on time of the second cylinder is adjusted according to the target load after torque limitation.

[0079] Specifically, after calculating and determining the first energizing time of each of the second cylinders based on the target load, it is necessary to determine whether the first energizing time exceeds the limit. If the first energizing time is greater than the eleventh threshold, it is determined that the energizing time is too long and may damage the engine. At this time, the engine torque is limited, and the energizing time of the second cylinder is readjusted after the torque is limited.

[0080] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the engine misfire degradation method of this application will be described in detail below with reference to specific embodiments.

[0081] This embodiment relates to a specific method for degrading engine misfire, such as... Figure 5 As shown, it includes the following steps:

[0082] Step S1: Obtain the engine misfire rate. If the misfire rate exceeds the first threshold and the duration exceeds the second threshold, diagnose the secondary voltage of the ignition coil.

[0083] Step S2: When the secondary voltage of the ignition coil is less than the third threshold, increase the ignition energy to test whether the misfire rate decreases;

[0084] Step S3: Record the ignition energy and the number of adjustments under the current operating condition when the misfire rate decreases. If the number of adjustments exceeds the fourth threshold, report the ignition fault and reset the ignition energy.

[0085] Step S4: If the secondary voltage is greater than the third threshold, increase the air-fuel ratio and test whether the ignition rate decreases. If the ignition rate does not decrease, decrease the air-fuel ratio and test whether the ignition rate decreases.

[0086] Step S5: If the ignition rate does not decrease, monitor the engine misfire rate until the misfire rate is greater than the fifth threshold. Control the engine and, if the engine is a multi-point injection engine, shut down the misfire cylinder and let the normal cylinder share the load.

[0087] Step S6: When the engine is a single-point injection engine or a multi-point injection engine and the normal cylinder's energizing time reaches the upper limit, torque limiting is applied.

[0088] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0089] This application also provides a downgrade device for engine misfire. It should be noted that the downgrade device for engine misfire in this application can be used to execute the downgrade method for engine misfire provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0090] The following describes the engine misfire degradation device provided in the embodiments of this application.

[0091] Figure 6 This is a structural block diagram of an engine misfire degradation device according to an embodiment of this application. Figure 6 As shown, the device includes:

[0092] The first acquisition unit 10 is used to acquire a first misfire rate. When the first misfire rate is greater than a first threshold, it acquires a first target voltage and queries a first mapping relationship based on the first misfire rate to obtain a target duration. The first misfire rate is the real-time misfire rate of the engine. The target duration is the maximum control duration for controlling the engine to reduce the first misfire rate. The first mapping relationship is the mapping relationship between the misfire rate and the maximum control duration. The first target voltage is the voltage of the ignition coil of the engine.

[0093] Specifically, in the event of an engine misfire, the current real-time misfire rate is obtained to obtain the aforementioned first misfire rate. If the first misfire rate exceeds a first threshold, it is determined that the first misfire rate affects the stability of engine operation. To avoid damage to the catalyst caused by misfire rate fluctuations during engine control, this application sets a maximum time limit for adjusting the engine at different misfire rates without damaging the catalyst, resulting in the aforementioned target duration. Engine control is then necessary to reduce the misfire rate. Because the misfire rate and the catalyst temperature rise are linear or approximately related, in one embodiment, a correspondence between the misfire rate and the target duration is constructed to obtain the aforementioned first mapping relationship.

[0094] The first control unit 20 is configured to, when the first target voltage is less than the second threshold, sequentially control the ignition coil to ignite according to the multiple second target voltages and obtain the corresponding real-time misfire rate to obtain multiple second misfire rates, and determine the second target voltage with the smallest corresponding second misfire rate as the ignition voltage of the ignition coil, wherein the second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold.

[0095] Specifically, as mileage increases, the spark plug gap may widen, leading to a higher ignition energy required for ignition. Since the engine's set ignition voltage may not meet the increased ignition energy, misfire may occur. Therefore, in one embodiment, this application sets up a method to obtain the aforementioned first target voltage by acquiring the voltage of the secondary ignition coil. If the first target voltage is less than a first threshold, it is determined that there is a possibility of misfire due to low ignition energy. At this time, the first target voltage is increased to obtain multiple second target voltages, and ignition is attempted sequentially to obtain the corresponding misfire rate. If the misfire rate decreases, the second target voltage with the lowest misfire rate is determined as the updated set ignition voltage for the engine.

[0096] The second control unit 30 is configured to acquire a first set value when the difference between the second misfire rate and the first misfire rate is less than a fourth threshold, control the engine to ignite according to multiple second set values ​​and acquire the corresponding real-time misfire rate to obtain multiple third misfire rates, and determine the second set value with the smallest corresponding third misfire rate as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than a fifth threshold.

[0097] Specifically, during the process of adjusting the engine ignition based on the ignition voltage, the misfire rate does not change significantly. That is, when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, the current air-fuel ratio of the engine is obtained to obtain the first set value. Then, the engine is adjusted within a preset range based on the first set value and ignition is attempted. The corresponding real-time misfire rate is recorded to obtain the third misfire rate. The second set value with the smallest third misfire rate is determined as the air-fuel ratio when the engine is set to ignite, i.e., the target air-fuel ratio.

[0098] The third control unit 40 is configured to adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine when the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold within the target duration, wherein the seventh threshold is greater than the first threshold.

[0099] Specifically, when adjusting the engine's ignition voltage and air-fuel ratio has no significant effect on reducing the engine's ignition rate (i.e., the difference between the third misfire rate and the first misfire rate is less than the sixth threshold within the target time period), and / or the engine misfire rate exceeds the set value (i.e., the first misfire rate is greater than the seventh threshold), the engine's ignition system is determined to be faulty. In the event of an ignition system fault, to ensure normal vehicle operation, this application sets up torque limiting and / or adjusts the energizing time of each cylinder to distribute the output torque of the misfired cylinder to the normal cylinder, ensuring stable vehicle operation before repair.

[0100] In this embodiment, the first acquisition unit acquires a first misfire rate and obtains a target duration by querying a first mapping relationship based on the first misfire rate. When the first misfire rate is greater than a first threshold and the duration is greater than the target duration, a first target voltage is acquired. The first misfire rate is the engine's real-time misfire rate, and the first misfire rate represents the maximum duration for which the catalyst in the engine will not be damaged. The first mapping relationship is the mapping relationship between the misfire rate and the duration. The first target voltage is the voltage of the engine's ignition coil. When the first target voltage is less than a second threshold, the first control unit sequentially controls the ignition coil to ignite based on multiple second target voltages and acquires the corresponding real-time misfire rate to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage. The second target voltage and the difference between the second target voltage and the first target voltage are less than a third threshold; when the difference between the second misfire rate and the first misfire rate are both less than a fourth threshold, the second control unit obtains a first set value, controls the engine to ignite according to multiple second set values ​​and obtains the corresponding real-time misfire rate to obtain multiple third misfire rates, and determines the second set value with the smallest corresponding third misfire rate as the target air-fuel ratio of the engine, the first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than a fifth threshold; when the difference between the third misfire rate and the first misfire rate are both less than a sixth threshold and / or the first misfire rate is greater than a seventh threshold, the third control unit adjusts the first ignition time of each cylinder of the engine and / or limits the torque of the engine, and the seventh threshold is greater than the first threshold. This application sets a first threshold and a seventh threshold. When the misfire rate is greater than the first threshold but less than the seventh threshold, the misfire rate is reduced by sequentially adjusting the voltage of the ignition coil and the air-fuel ratio of the engine. When the misfire rate is greater than the seventh threshold, injection is cut off to the misfired cylinder and / or torque is limited in the engine. This application implements a graded downgrading mechanism for the engine. Compared to the prior art where torque is immediately limited when the misfire rate reaches a fault threshold, this application solves the problem in the prior art where there is no adjustment measure when the misfire rate has not reached the fault threshold, resulting in speed fluctuations and poor fuel economy and comfort.

[0101] To ensure that the catalyst is not damaged, in one optional embodiment, the apparatus further includes:

[0102] The second acquisition unit is used to acquire the target speed and target load after obtaining the target duration by querying the first mapping relationship based on the first misfire rate, and to obtain the target coefficient by querying the second mapping relationship based on the target speed and the target load. The target speed is the speed of the engine, the load is the load of the engine, the target coefficient is the correction coefficient of the target duration, and the second mapping relationship is the mapping relationship between the speed, the load and the correction coefficient.

[0103] Specifically, the engine operates differently under different speeds and loads, thus altering the impact of the misfire rate on the catalyst. Therefore, to ensure no damage to the catalyst, this application calibrates the maximum time at which the misfire rate does not damage the catalyst, determining correction coefficients for different speeds and loads, thus obtaining the aforementioned second mapping relationship. Therefore, by obtaining the real-time speed and load of the engine with the first misfire rate, i.e., obtaining the target speed and target load, the corresponding correction coefficients can be retrieved based on the target load and target speed.

[0104] The calculation unit is used to calculate the product of the above target coefficient and the above target duration to obtain the corrected duration.

[0105] Specifically, the target duration is adjusted based on the target coefficient to obtain the adjusted duration corresponding to the current working condition.

[0106] To reduce the aforementioned first fire failure rate, in one optional implementation, such as Figure 3 As shown, the first control unit includes:

[0107] The first acquisition module is used to acquire the length of the first interval, determine the first target interval based on the first interval length and the first target voltage, and the minimum value of the first target interval is the first target voltage.

[0108] Specifically, there is an upper limit to the voltage adjustment of the ignition coil. The difference between the first target voltage and the upper limit is determined to obtain the length of the first interval. Then, the range of the second target voltage is determined to obtain the first target interval.

[0109] The first extraction module is used to randomly select multiple voltages in the first target interval to obtain multiple second target voltages.

[0110] Specifically, multiple second target voltages are obtained by randomly selecting voltages within the first target range as adjusted test voltages.

[0111] The first arrangement module is used to arrange the second target voltages from smallest to largest, and to determine the energizing time of the corresponding ignition coil based on each of the second target voltages to obtain multiple second energizing times.

[0112] Specifically, the voltage of the ignition coil is affected by the ignition coil's energizing time. Therefore, this application sets the second target voltage to be arranged from smallest to largest, and calculates the corresponding second energizing time of the ignition coil according to the second target voltage.

[0113] The first control module is used to control the ignition coils to ignite sequentially according to the second power-on time, from smallest to largest.

[0114] Specifically, the ignition coil is energized sequentially according to the second energizing time to initiate ignition and make an attempt.

[0115] To avoid losses caused by ignition coil failure, in one optional embodiment, the above-mentioned device further includes:

[0116] The third acquisition unit is used to, after determining the second target voltage corresponding to the minimum second misfire rate as the ignition voltage of the ignition coil, acquire the target number of times the ignition voltage is updated under different target speeds and target loads, and determine the ignition coil fault if the target number is greater than an eighth threshold.

[0117] Specifically, the target speed and target load for adjusting the ignition voltage of the ignition coil are recorded. The number of adjustments is determined under the same target speed and target load. If adjustments are made multiple times under the same operating conditions within a short period of time, i.e., if the number of adjustments exceeds the eighth threshold, an ignition coil fault is determined, an alarm is triggered, and the driver is prompted to carry out maintenance.

[0118] To reduce the aforementioned second fire failure rate, in one optional implementation, such as Figure 4 As shown, the second control unit includes:

[0119] The second acquisition module is used to acquire the length of the second interval, and determine the second target interval and the third target interval based on the length of the second interval and the first set value. The minimum value of the second target interval is the first set value, and the maximum value of the third target interval is the first set value.

[0120] Specifically, the air-fuel ratio adjustment of the aforementioned engine has a maximum and a minimum value. The maximum range of air-fuel ratio adjustment is determined based on the difference between the limit value and the aforementioned first preset value, resulting in the aforementioned second interval length. Then, based on the aforementioned second interval length, the interval from which the first preset value is taken upwards is determined to obtain the aforementioned second target interval. Finally, based on the aforementioned second interval length, the interval from which the first preset value is taken downwards is determined to obtain the aforementioned third target interval.

[0121] The second extraction module is used to randomly select multiple air-fuel ratios within the aforementioned second target range to obtain multiple third set values;

[0122] Specifically, firstly, the air-fuel ratio of the engine is increased, and then multiple air-fuel ratios are randomly selected within the second target range as the test air-fuel ratios to obtain multiple third set values.

[0123] The second arrangement module is used to control the engine to ignite in order from small to large according to the third set value, and obtain the corresponding real-time misfire rate to obtain the fourth misfire rate.

[0124] Specifically, during the experiment, the air-fuel ratio was increased sequentially and ignition was performed in each ignition cycle, and the corresponding real-time misfire rate was recorded to obtain the aforementioned fourth misfire rate.

[0125] The third extraction module is used to randomly select multiple air-fuel ratios in the third target range to obtain the second set value when the difference between the fourth misfire rate and the first misfire rate is less than the ninth threshold.

[0126] Specifically, when increasing the air-fuel ratio has little effect on controlling and adjusting the engine, that is, when the difference between the fourth misfire rate and the first misfire rate is less than the ninth threshold, the air-fuel ratio of the engine is reduced, and multiple air-fuel ratios are randomly selected in the third space as the test air-fuel ratios to obtain the second set value.

[0127] The second control module is used to control the engine to ignite sequentially according to the second set value, from smallest to largest.

[0128] Specifically, during the experiment, the air-fuel ratio was increased sequentially and ignition was performed in each ignition cycle, and the corresponding real-time misfire rate was recorded to obtain the aforementioned third misfire rate.

[0129] In the event of an ignition coil failure, to ensure stable engine operation, in one optional implementation, the third control unit includes:

[0130] The third acquisition module is used to acquire the injection type of the engine, and when the injection type is single-point injection, to limit the torque of the engine.

[0131] Specifically, engine injection types are divided into single-point injection and multi-point injection. In order to ensure stable engine operation in the event of engine misfire, when the engine injection type is single-point injection, torque is limited to stabilize the engine's operating state.

[0132] The determination module is used to determine the first cylinder and the second cylinder when the above-mentioned injection type is multi-point injection, and to control the first cylinder to cut off the injection when the first cylinder is less than the tenth threshold. The first cylinder is the misfired cylinder and the second cylinder is the non-misfired cylinder.

[0133] Specifically, when the engine uses multi-point injection, the engine cylinders are inspected to identify the cylinder experiencing a misfire, which is designated as the first cylinder, and the cylinders without misfires are designated as the second cylinder. If the number of first cylinders is less than the tenth threshold, it is determined that the first cylinder can be shut down, and the output torque of the first cylinder can be shared by the second cylinder.

[0134] The third control unit is used to adjust the first energizing time of the second cylinder according to the target load to keep the target load unchanged.

[0135] Specifically, adjusting the output torque of the second cylinder includes readjusting the load of each second cylinder according to the target load, and then adjusting the energizing time of the cylinder, i.e., adjusting the first energizing time to maintain the target load stable.

[0136] To prevent engine damage, in one optional embodiment, the above-mentioned device further includes:

[0137] The fourth control unit is configured to, after adjusting the first energizing time of the second cylinder according to the target load, limit the torque of the engine if the first energizing time is greater than the eleventh threshold, and adjust the first energizing time of the second cylinder according to the target load after the torque limit.

[0138] Specifically, after calculating and determining the first energizing time of each of the second cylinders based on the target load, it is necessary to determine whether the first energizing time exceeds the limit. If the first energizing time is greater than the eleventh threshold, it is determined that the energizing time is too long and may damage the engine. At this time, the engine torque is limited, and the energizing time of the second cylinder is readjusted after the torque is limited.

[0139] The aforementioned engine misfire degradation device includes a processor and a memory. The first acquisition unit, first control unit, second control unit, and third control unit are all stored as program units in the memory, and the processor executes the program units stored in the memory to achieve the corresponding functions. All of the above modules are located in the same processor; alternatively, the modules may be located in different processors in any combination.

[0140] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and precise handling of engine misfires can be achieved by adjusting kernel parameters.

[0141] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0142] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the engine misfire degradation method.

[0143] Specifically, degraded methods for engine misfire include:

[0144] Step S201: Obtain a first misfire rate and query a first mapping relationship based on the first misfire rate to obtain a target duration. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, obtain a first target voltage. The first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration during which the catalyst in the engine will not be damaged, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine.

[0145] Specifically, in the event of an engine misfire, the current real-time misfire rate is obtained to obtain the aforementioned first misfire rate. If the first misfire rate exceeds a first threshold, it is determined that the first misfire rate affects the stability of engine operation. To avoid damage to the catalyst caused by misfire rate fluctuations during engine control, this application sets a maximum time limit for adjusting the engine at different misfire rates without damaging the catalyst, resulting in the aforementioned target duration. Engine control is then necessary to reduce the misfire rate. Because the misfire rate and the catalyst temperature rise are linear or approximately related, in one embodiment, a correspondence between the misfire rate and the target duration is constructed to obtain the aforementioned first mapping relationship.

[0146] Step S202: When the first target voltage is less than the second threshold, the ignition coil is controlled to ignite according to the multiple second target voltages and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold.

[0147] Specifically, as mileage increases, the spark plug gap may widen, leading to a higher ignition energy required for ignition. Since the engine's set ignition voltage may not meet the increased ignition energy, misfire may occur. Therefore, in one embodiment, this application sets up a method to obtain the aforementioned first target voltage by acquiring the voltage of the secondary ignition coil. If the first target voltage is less than a first threshold, it is determined that there is a possibility of misfire due to low ignition energy. At this time, the first target voltage is increased to obtain multiple second target voltages, and ignition is attempted sequentially to obtain the corresponding misfire rate. If the misfire rate decreases, the second target voltage with the lowest misfire rate is determined as the updated set ignition voltage for the engine.

[0148] Step S203: When the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates, and the second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold.

[0149] Specifically, during the process of adjusting the engine ignition based on the ignition voltage, the misfire rate does not change significantly. That is, when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, the current air-fuel ratio of the engine is obtained to obtain the first set value. Then, the engine is adjusted within a preset range based on the first set value and ignition is attempted. The corresponding real-time misfire rate is recorded to obtain the third misfire rate. The second set value with the smallest third misfire rate is determined as the air-fuel ratio when the engine is set to ignite, i.e., the target air-fuel ratio.

[0150] Step S204: If the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine, wherein the seventh threshold is greater than the first threshold.

[0151] Specifically, when adjusting the engine's ignition voltage and air-fuel ratio has no significant effect on reducing the engine's ignition rate (i.e., the difference between the third misfire rate and the first misfire rate is less than the sixth threshold within the target time period), and / or the engine misfire rate exceeds the set value (i.e., the first misfire rate is greater than the seventh threshold), the engine's ignition system is determined to be faulty. In the event of an ignition system fault, to ensure normal vehicle operation, this application sets up torque limiting and / or adjusts the energizing time of each cylinder to distribute the output torque of the misfired cylinder to the normal cylinder, ensuring stable vehicle operation before repair.

[0152] This invention provides a processor for running a program, wherein the program executes the engine misfire degradation method.

[0153] Specifically, degraded methods for engine misfire include:

[0154] Step S201: Obtain a first misfire rate and query a first mapping relationship based on the first misfire rate to obtain a target duration. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, obtain a first target voltage. The first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration during which the catalyst in the engine will not be damaged, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine.

[0155] Specifically, in the event of an engine misfire, the current real-time misfire rate is obtained to obtain the aforementioned first misfire rate. If the first misfire rate exceeds a first threshold, it is determined that the first misfire rate affects the stability of engine operation. To avoid damage to the catalyst caused by misfire rate fluctuations during engine control, this application sets a maximum time limit for adjusting the engine at different misfire rates without damaging the catalyst, resulting in the aforementioned target duration. Engine control is then necessary to reduce the misfire rate. Because the misfire rate and the catalyst temperature rise are linear or approximately related, in one embodiment, a correspondence between the misfire rate and the target duration is constructed to obtain the aforementioned first mapping relationship.

[0156] Step S202: When the first target voltage is less than the second threshold, the ignition coil is controlled to ignite according to the multiple second target voltages and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold.

[0157] Specifically, as mileage increases, the spark plug gap may widen, leading to a higher ignition energy required for ignition. Since the engine's set ignition voltage may not meet the increased ignition energy, misfire may occur. Therefore, in one embodiment, this application sets up a method to obtain the aforementioned first target voltage by acquiring the voltage of the secondary ignition coil. If the first target voltage is less than a first threshold, it is determined that there is a possibility of misfire due to low ignition energy. At this time, the first target voltage is increased to obtain multiple second target voltages, and ignition is attempted sequentially to obtain the corresponding misfire rate. If the misfire rate decreases, the second target voltage with the lowest misfire rate is determined as the updated set ignition voltage for the engine.

[0158] Step S203: When the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates, and the second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold.

[0159] Specifically, during the process of adjusting the engine ignition based on the ignition voltage, the misfire rate does not change significantly. That is, when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, the current air-fuel ratio of the engine is obtained to obtain the first set value. Then, the engine is adjusted within a preset range based on the first set value and ignition is attempted. The corresponding real-time misfire rate is recorded to obtain the third misfire rate. The second set value with the smallest third misfire rate is determined as the air-fuel ratio when the engine is set to ignite, i.e., the target air-fuel ratio.

[0160] Step S204: If the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine, wherein the seventh threshold is greater than the first threshold.

[0161] Specifically, when adjusting the engine's ignition voltage and air-fuel ratio has no significant effect on reducing the engine's ignition rate (i.e., the difference between the third misfire rate and the first misfire rate is less than the sixth threshold within the target time period), and / or the engine misfire rate exceeds the set value (i.e., the first misfire rate is greater than the seventh threshold), the engine's ignition system is determined to be faulty. In the event of an ignition system fault, to ensure normal vehicle operation, this application sets up torque limiting and / or adjusts the energizing time of each cylinder to distribute the output torque of the misfired cylinder to the normal cylinder, ensuring stable vehicle operation before repair.

[0162] This invention provides a vehicle, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps:

[0163] Step S201: Obtain a first misfire rate and query a first mapping relationship based on the first misfire rate to obtain a target duration. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, obtain a first target voltage. The first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration during which the catalyst in the engine will not be damaged, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine.

[0164] Step S202: When the first target voltage is less than the second threshold, the ignition coil is controlled to ignite according to the multiple second target voltages and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold.

[0165] Step S203: When the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates, and the second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold.

[0166] Step S204: If the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine, wherein the seventh threshold is greater than the first threshold.

[0167] This application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having at least the following method steps:

[0168] Step S202: When the first target voltage is less than the second threshold, the ignition coil is controlled to ignite according to the multiple second target voltages and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold.

[0169] Step S203: When the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates, and the second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold.

[0170] Step S204: If the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine, wherein the seventh threshold is greater than the first threshold.

[0171] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0172] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0173] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0174] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0175] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0176] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0177] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0178] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0179] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0180] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0181] 1) The engine misfire degradation method of this application firstly obtains a first misfire rate and obtains a target duration by querying a first mapping relationship based on the first misfire rate. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, a first target voltage is obtained. The first misfire rate is the real-time misfire rate of the engine, the first misfire rate is the maximum duration for which the first misfire rate does not damage the catalyst in the engine, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine. Then, if the first target voltage is less than a second threshold, the ignition coil is sequentially controlled to ignite based on multiple second target voltages, and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The pressure is greater than the second target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold; then, when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, and the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates. The second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine. The difference between the second set value and the first set value is less than the fifth threshold; finally, when the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, the first ignition time of each cylinder of the engine is adjusted and / or the torque of the engine is limited. The seventh threshold is greater than the first threshold. This application sets a first threshold and a seventh threshold. When the misfire rate is greater than the first threshold but less than the seventh threshold, the misfire rate is reduced by sequentially adjusting the voltage of the ignition coil and the air-fuel ratio of the engine. When the misfire rate is greater than the seventh threshold, injection is cut off to the misfired cylinder and / or torque is limited in the engine. This application implements a graded downgrading mechanism for the engine. Compared to the prior art where torque is immediately limited when the misfire rate reaches a fault threshold, this application solves the problem in the prior art where there is no adjustment measure when the misfire rate has not reached the fault threshold, resulting in speed fluctuations and poor fuel economy and comfort.

[0182] 2) The engine misfire degradation device of this application includes a first acquisition unit that acquires a first misfire rate and obtains a target duration by querying a first mapping relationship based on the first misfire rate. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, a first target voltage is acquired. The first misfire rate is the real-time misfire rate of the engine, and the first misfire rate is the maximum duration for which the catalyst in the engine will not be damaged. The first mapping relationship is the mapping relationship between the misfire rate and the duration. The first target voltage is the voltage of the ignition coil of the engine. If the first target voltage is less than a second threshold, the first control unit sequentially controls the ignition coil to ignite based on multiple second target voltages and acquires the corresponding real-time misfire rate to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The pressure is greater than the second target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold; when the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, the second control unit obtains a first set value, controls the engine to ignite according to multiple second set values ​​and obtains the corresponding real-time misfire rate to obtain multiple third misfire rates, and determines the second set value with the smallest corresponding third misfire rate as the target air-fuel ratio of the engine, the first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold; when the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, the third control unit adjusts the first ignition time of each cylinder of the engine and / or limits the torque of the engine, and the seventh threshold is greater than the first threshold. This application sets a first threshold and a seventh threshold. When the misfire rate is greater than the first threshold but less than the seventh threshold, the misfire rate is reduced by sequentially adjusting the voltage of the ignition coil and the air-fuel ratio of the engine. When the misfire rate is greater than the seventh threshold, injection is cut off to the misfired cylinder and / or torque is limited in the engine. This application implements a graded downgrading mechanism for the engine. Compared to the prior art where torque is immediately limited when the misfire rate reaches a fault threshold, this application solves the problem in the prior art where there is no adjustment measure when the misfire rate has not reached the fault threshold, resulting in speed fluctuations and poor fuel economy and comfort.

[0183] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for degrading engine misfire, characterized in that, include: A first misfire rate is obtained, and a target duration is obtained by querying a first mapping relationship based on the first misfire rate. If the first misfire rate is greater than a first threshold and the duration is greater than the target duration, a first target voltage is obtained. The first misfire rate is the real-time misfire rate of the engine, the target duration is the maximum duration during which the first misfire rate does not cause damage to the catalyst in the engine, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine. When the first target voltage is less than the second threshold, the ignition coil is controlled to ignite according to the multiple second target voltages and the corresponding real-time misfire rate is obtained to obtain multiple second misfire rates. The second target voltage with the smallest corresponding second misfire rate is determined as the ignition voltage of the ignition coil. The second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold. When the difference between the second misfire rate and the first misfire rate is less than the fourth threshold, a first set value is obtained, and the engine is controlled to ignite according to multiple second set values ​​and the corresponding real-time misfire rate is obtained to obtain multiple third misfire rates. The second set value with the smallest corresponding third misfire rate is determined as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than the fifth threshold. If the difference between the third misfire rate and the first misfire rate is less than the sixth threshold and / or the first misfire rate is greater than the seventh threshold, the first energizing time of each cylinder of the engine is adjusted and / or the engine torque is limited, wherein the seventh threshold is greater than the first threshold.

2. The method according to claim 1, characterized in that, After obtaining the target duration by querying the first mapping relationship based on the first fire failure rate, the method further includes: Obtain the target speed and target load, and query the second mapping relationship based on the target speed and target load to obtain the target coefficient. The target speed is the engine speed, the load is the engine load, the target coefficient is the correction coefficient for the target duration, and the second mapping relationship is the mapping relationship between the speed, the load and the correction coefficient. The corrected duration is obtained by multiplying the target coefficient by the target duration.

3. The method according to claim 2, characterized in that, The ignition coil is sequentially controlled to ignite based on multiple second target voltages, including: Obtain the length of the first interval, determine the first target interval based on the length of the first interval and the first target voltage, and the minimum value of the first target interval is the first target voltage; Multiple voltages are randomly selected from the first target interval to obtain multiple second target voltages; Arrange the second target voltages from smallest to largest, and determine the corresponding energizing time of the ignition coil based on each second target voltage to obtain multiple second energizing times; The ignition coils are ignited sequentially according to the second power-on time, from smallest to largest.

4. The method according to claim 2, characterized in that, After determining the second target voltage corresponding to the minimum second misfire rate as the ignition voltage of the ignition coil, the method further includes: The number of times the ignition voltage is updated under different target speeds and target loads is obtained to obtain the target number. If the target number is greater than an eighth threshold, the ignition coil is determined to be faulty.

5. The method according to claim 1, characterized in that, The engine is controlled to ignite according to multiple second set values, including: Obtain the length of the second interval, and determine the second target interval and the third target interval based on the length of the second interval and the first set value. The minimum value of the second target interval is the first set value, and the maximum value of the third target interval is the first set value. Multiple air-fuel ratios are randomly selected within the second target range to obtain multiple third set values; The engine is ignited sequentially according to the third set value from smallest to largest, and the corresponding real-time misfire rate is obtained to obtain the fourth misfire rate; When the difference between the fourth misfire rate and the first misfire rate is less than the ninth threshold, multiple air-fuel ratios are randomly selected from the third target range to obtain the second set value. The engine is ignited sequentially according to the second set value, from smallest to largest.

6. The method according to claim 2, characterized in that, Adjusting the first energization time of each cylinder of the engine and / or limiting the torque of the engine includes: Obtain the injection type of the engine, and if the injection type is single-point injection, limit the torque of the engine; When the injection type is multi-point injection, the first cylinder and the second cylinder are determined. When the first cylinder is less than the tenth threshold, the first cylinder is controlled to cut off the injection. The first cylinder is the misfired cylinder, and the second cylinder is the non-misfired cylinder. The first energizing time of the second cylinder is adjusted according to the target load to keep the target load constant.

7. The method according to claim 6, characterized in that, After adjusting the first energizing time of the second cylinder according to the target load, the method further includes: If the first power-on time is greater than the eleventh threshold, the engine torque is limited, and the first power-on time of the second cylinder is adjusted according to the target load after torque limitation.

8. A degradation device for engine misfire, characterized in that, The device includes: The first acquisition unit is used to acquire a first misfire rate and query a first mapping relationship based on the first misfire rate to obtain a target duration. When the first misfire rate is greater than a first threshold and the duration is greater than the target duration, the first target voltage is acquired. The first misfire rate is the real-time misfire rate of the engine, the target duration is the maximum duration during which the first misfire rate does not cause damage to the catalyst in the engine, the first mapping relationship is the mapping relationship between the misfire rate and the duration, and the first target voltage is the voltage of the ignition coil of the engine. The first control unit is configured to, when the first target voltage is less than the second threshold, sequentially control the ignition coil to ignite according to a plurality of second target voltages and obtain the corresponding real-time misfire rate to obtain a plurality of second misfire rates, and determine the second target voltage with the smallest corresponding second misfire rate as the ignition voltage of the ignition coil, wherein the second target voltage is greater than the first target voltage and the difference between the second target voltage and the first target voltage is less than the third threshold. The second control unit is configured to acquire a first set value when the difference between the second misfire rate and the first misfire rate is less than a fourth threshold, control the engine to ignite according to multiple second set values ​​and acquire the corresponding real-time misfire rate to obtain multiple third misfire rates, and determine the second set value with the smallest corresponding third misfire rate as the target air-fuel ratio of the engine. The first set value is used to characterize the air-fuel ratio of the engine, and the difference between the second set value and the first set value is less than a fifth threshold. The third control unit is configured to adjust the first energizing time of each cylinder of the engine and / or limit the torque of the engine when the difference between the third misfire rate and the first misfire rate is less than a sixth threshold and / or the first misfire rate is greater than a seventh threshold, wherein the seventh threshold is greater than the first threshold.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising methods for performing any one of claims 1 to 7.

Images