A method for calibrating ignition retard angle, a storage medium, a powertrain and an automobile

Abstract

An embodiment of the present application provides a method for calibrating a retarding ignition angle, a storage medium, a powertrain, and an automobile. The calibration method includes: determining a plurality of operating conditions of the engine according to the intake air temperature of the engine, the load of the engine, and the rotational speed of the engine; obtaining the corresponding temperature coefficient for each operating condition according to all the determined operating conditions; acquiring the corresponding basic ignition angle and retardation coefficient for each preset operating condition, where the preset operating condition is the operating condition corresponding to the initial intake air temperature among all the determined operating conditions; and obtaining the retarding ignition angle corresponding to the operating condition at different intake air temperatures for the corresponding load and the corresponding rotational speed according to the corresponding basic ignition angle and retardation coefficient for each preset operating condition, and the temperature coefficient corresponding to the operating condition at different intake air temperatures for the corresponding load and the corresponding rotational speed. The retarding angle calibration method provided by the embodiment of the present application avoids the need for repeated calibration using a combustion analyzer and a knock speaker when performing temperature correction on the retarding ignition angle, and improves the calibration efficiency.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular, to a method for calibrating a retarding ignition angle, a storage medium, a powertrain, and an automobile. Background Art

[0002] Knock refers to the self-ignition of the remaining exhaust gas that has not burned after ignition in the combustion chamber. The shock wave generated by this self-ignition will damage the thermal boundary layer formed on the inner wall surface of the combustion chamber. Engine knock can cause significant damage to the engine.

[0003] To avoid engine knock, it is necessary to retard the ignition. In the case of retarding the ignition, the angle turned by the crankshaft from the ignition moment to when the piston reaches top dead center of compression is the retarding ignition angle. The retarding ignition angle is related to the intake air temperature, engine speed, and load of the engine. In the related art, there is a problem that the working time for calibrating the retarding ignition angle at different intake air temperatures is relatively long. Summary of the Invention

[0004] In view of this, embodiments of the present application are expected to provide a method for calibrating a retarding ignition angle, a storage medium, a powertrain, and an automobile, so as to solve the problem of long test working time for calibrating the retarding ignition angle at different intake air temperatures.

[0005] Embodiments of the present application provide a method for calibrating a retarding ignition angle, including:

[0006] Determining a plurality of operating conditions of the engine according to the intake air temperature of the engine, the load of the engine, and the engine speed;

[0007] Obtaining a temperature coefficient corresponding to each of the determined operating conditions according to all the determined operating conditions;

[0008] Obtaining a base ignition angle and a retarding coefficient corresponding to each preset operating condition, where the preset operating condition is the operating condition corresponding to the initial intake air temperature among all the determined operating conditions;

[0009] Obtaining the retarding ignition angle corresponding to the load and the engine speed at different intake air temperatures according to the base ignition angle and the retarding coefficient corresponding to each preset operating condition, and the temperature coefficient corresponding to the operating condition corresponding to the load and the engine speed at different intake air temperatures.

[0010] In some embodiments, obtaining a temperature coefficient corresponding to each of the determined operating conditions according to all the determined operating conditions includes:

[0011] Determining a corresponding vector group according to each operating condition of the engine;

[0012] Determine the kernel function of the temperature coefficient with respect to the vector group according to all the determined operating conditions;

[0013] Determine the temperature coefficient corresponding to each vector group according to the kernel function.

[0014] In some embodiments, the kernel function of the temperature coefficient with respect to the vector group is a Gaussian kernel function:

[0015]

[0016] In the formula, Φ is the temperature coefficient;

[0017] x is the vector group corresponding to the operating condition, x = (N i , M i , T i );

[0018] wherein, N i is the rotational speed under the i-th operating condition, M i is the load under the i-th operating condition, T i is the intake air temperature under the i-th operating condition, and i is a natural number greater than 0 and less than or equal to n;

[0019] c is the center point of the Gaussian kernel function;

[0020] σ is the bandwidth of the Gaussian kernel function.

[0021] In some embodiments, obtaining the retarding ignition angle according to the base ignition angle, the retardation coefficient, and the temperature coefficient corresponding to each determined operating condition includes:

[0022] Determine the retarding ignition angle according to the first correction angle and the second correction angle; the first correction angle is the product of the base ignition angle, the temperature coefficient, and the retardation coefficient, and the second correction angle is the correction angle of the base ignition angle when the gas discharged from the engine passes through the exhaust gas treatment system.

[0023] In some embodiments, when the gas discharged from the engine passes through the exhaust gas treatment system, the intake air temperature is equal to the temperature after the turbine minus the intercooling loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature, plus the exhaust gas treatment system outlet temperature.

[0024] In some embodiments, when the gas discharged from the engine does not pass through the exhaust gas treatment system, the retarding ignition angle is the product of the base ignition angle and the retardation coefficient and the temperature coefficient.

[0025] In some embodiments, when the gas discharged from the engine does not pass through the exhaust gas treatment system, the intake air temperature is equal to the temperature after the turbine minus the intercooling loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature.

[0026] An embodiment of the present application also provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the calibration method of any one of the ignition retard angles.

[0027] An embodiment of the present application also provides a powertrain, including:

[0028] A memory configured to store a computer program;

[0029] A processor configured to execute the stored computer program to implement the calibration method of any one of the ignition retard angles.

[0030] An embodiment of the present application also provides a vehicle, including:

[0031] A vehicle body;

[0032] Any one of the powertrains, and the powertrain is installed on the vehicle body.

[0033] The ignition retard calibration method of the engine provided by the embodiment of the present application obtains corresponding temperature coefficients through multiple determined engine operating conditions. The ignition retard angle is calibrated by using the temperature coefficient, the retard coefficient at the initial intake air temperature, and the basic ignition angle. It avoids the need to repeatedly calibrate using a combustion analyzer and a knock speaker when performing temperature correction on the ignition retard angle. The implementation scheme of the present application does not require a large number of repetitive tests to complete the temperature correction of the ignition retard angle, improving the calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic flow chart of the ignition retard calibration method of the engine according to an embodiment of the present application;

[0035] Figure 2 It is a schematic diagram of a powertrain according to an embodiment of the present application;

[0036] Figure 3 It is a schematic diagram of the calculation process of the ignition retard angle according to an embodiment of the present application;

[0037] Figure 4 It is a schematic diagram of the calculation process of the ignition retard angle according to another embodiment of the present application;

[0038] Figure 5 It is a schematic flow chart of obtaining the corresponding temperature coefficient for each operating condition according to all determined operating conditions in an embodiment of the present application.

[0039] Description of the reference numerals: Powertrain 1; Memory 10; Processor 11. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments may be combined with each other. The detailed description in the specific implementation manners should be understood as an explanatory illustration of the gist of the present application and should not be regarded as an improper limitation of the present application.

[0041] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. In the description of the embodiments of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0042] As part of the creative concept of the present application, before describing the embodiments of the present application, it is necessary to analyze the reasons for the long test working time of calibrating the ignition retard angle at different intake air temperatures in the related art, and obtain the technical solutions of the embodiments of the present application through reasonable analysis.

[0043] In the related art, most of the calibrations are for the engine speed and load at a specific intake air temperature. If different intake air temperatures are encountered, it is necessary to repeatedly determine whether the adjusted ignition retard angle is appropriate through a combustion analyzer and a knock speaker for each intake air temperature. This process takes a long time, and a lot of work is repetitive.

[0044] The embodiments of the present application provide a method for calibrating the ignition retard angle. Please refer to Figure 1 , and the calibration method includes:

[0045] Step S1: Determine multiple working conditions of the engine according to the intake air temperature, load, and speed of the engine;

[0046] Step S2: Obtain the corresponding temperature coefficient for each working condition according to all determined working conditions;

[0047] Step S3: Obtain the base ignition angle and retard coefficient corresponding to each preset working condition, where the preset working condition is the working condition corresponding to the initial intake air temperature among all determined working conditions;

[0048] Step S4: Obtain the ignition retard angle corresponding to the working condition of the corresponding load and corresponding speed at different intake air temperatures according to the base ignition angle and retard coefficient corresponding to each preset working condition and the temperature coefficient corresponding to the working condition of the corresponding load and corresponding speed at different intake air temperatures.

[0049] In this embodiment, the corresponding temperature coefficients are obtained through multiple determined engine working conditions. The ignition retard angle calibration is completed by using the temperature coefficient, the retard coefficient, and the base ignition angle at a specific temperature. It avoids the need to repeatedly calibrate the ignition retard angle using a combustion analyzer and a knock speaker when performing temperature correction on the ignition retard angle. The implementation scheme of the present application does not require a large number of repetitive tests to complete the temperature correction of the ignition retard angle, improving the calibration efficiency.

[0050] It should be noted that the multiple operating conditions of the engine determined in step S1 are a finite number of discrete operating conditions, rather than an infinite number of operating conditions.

[0051] Exemplarily, the number of operating conditions of the engine determined in step S1 is n, where n is a natural number greater than zero. For example, the number of operating conditions of the engine determined in step S1 is 100.

[0052] It should be noted that all the determined operating conditions in step S2 are all the operating conditions of the engine determined in step S1.

[0053] Exemplarily, when the number of operating conditions of the engine determined in step S1 is 100, all the determined operating conditions are the 100 operating conditions determined in step S1.

[0054] Exemplarily, when the number of operating conditions of the engine determined in step S1 is 100, each determined operating condition is each of the 100 operating conditions determined in step S1.

[0055] Exemplarily, the preset operating conditions in step S3 are all the operating conditions with an intake air temperature of 30°C among the multiple operating conditions of the engine in step S1. Obtain the temperature coefficients of all the multiple operating conditions of the engine in step S1 through step S2; determine the engine speed and load, and obtain the temperature coefficient under the current operating condition according to the temperature coefficients obtained in step S2; substitute the determined engine speed and load into the basic ignition angle and retard angle coefficient obtained in step S3 to obtain the basic ignition angle and retard angle coefficient under the current operating condition; obtain the corresponding retard ignition angle according to the temperature coefficient, basic ignition angle and retard angle coefficient under the current operating condition.

[0056] It should be noted that both the basic ignition angle and the retard ignition angle are the angles through which the crankshaft rotates during the period from the ignition moment to the piston reaching the top dead center of compression.

[0057] It should be noted that it is easy to generate knocking when the engine determines the ignition moment using the basic ignition angle, so it is necessary to delay the ignition moment, that is, the retard ignition angle is less than the basic ignition angle.

[0058] In one embodiment, the basic ignition angle can be obtained by substituting the preset operating conditions into the basic ignition angle map.

[0059] In one embodiment, the retard angle coefficient can be obtained through experiments by adjusting the engine speed and load at the initial intake air temperature.

[0060] It can be understood that the basic ignition angle and the retard angle coefficient are known quantities that can be read by the controller.

[0061] It should be noted that the basic ignition angle and the retard coefficient can be stored in a memory for the controller to call. The following will detail each step of the engine retard calibration method of the present application.

[0062] The parameters affecting the engine retard calibration include the intake air temperature of the engine, the load of the engine, and the engine speed. Adjusting any one of the three parameters requires corresponding adjustment of the engine's ignition retard angle to reduce engine knocking. The engine operating conditions can be determined through the three parameters of the engine's intake air temperature, load, and speed.

[0063] In one embodiment, the adjustment range of the engine's intake air temperature is from 25°C to 60°C, and the adjustment step is 2.5°C.

[0064] Exemplarily, to select a suitable intake air temperature, the i-th temperature is T i , T i = (25 + 2.5 * (i - 1))°C, where i is a natural number greater than 0 and less than or equal to n.

[0065] In one embodiment, the adjustment range of the engine's load is from 200 mg / L to 2200 mg / L, and the adjustment step is 100 mg / L.

[0066] Exemplarily, to select a suitable load, the i-th load is M i , M i = (200 + 100 * (i - 1)) mg / L, where i is a natural number greater than 0 and less than or equal to n.

[0067] In one embodiment, when the engine's load is greater than or equal to 1000 mg / L and less than or equal to 2200 mg / L, the adjustment step can be 200 mg / L.

[0068] In one embodiment, the adjustment range of the engine's speed is from 1000 rpm to 5200 rpm, and the adjustment step is 250 rpm.

[0069] Exemplarily, to select a suitable speed, the i-th speed is N i , N i = (1000 + 250 * (i - 1)) rpm, where i is a natural number greater than 0 and less than or equal to n.

[0070] In one embodiment, when the engine's speed is greater than 2000 rpm and less than or equal to 5200 rpm, the adjustment step can be 500 rpm.

[0071] It should be noted that "rpm" represents revolutions per minute.

[0072] Exemplarily, please refer to Figure 5, obtain the corresponding temperature coefficient under each working condition according to all determined working conditions, including:

[0073] Step S21: Determine the corresponding vector group according to each working condition of the engine;

[0074] Step S22: Determine the kernel function of the temperature coefficient with respect to the vector group according to all determined working conditions;

[0075] Step S23: Determine the temperature coefficient corresponding to each vector group according to the kernel function.

[0076] In this embodiment, the kernel function is used to deal with the problems among the temperature coefficient, intake air temperature, rotational speed and load. During the calibration process, the temperature coefficient can be directly determined according to the intake air temperature, rotational speed and load of the engine, so as to perform temperature correction on the ignition retard angle.

[0077] In one embodiment, by using non-linear transformation, the non-linear relationship between the temperature coefficient and the vector group corresponding to the working condition is directly transformed into a linear relationship problem.

[0078] In one embodiment, a neural network is used to construct a neuron model, and a non-linear function is used to represent the relationship between the temperature coefficient and the vector group corresponding to the working condition.

[0079] Exemplarily, the kernel function of the temperature coefficient with respect to the vector group is a Gaussian kernel function:

[0080]

[0081] In the formula, Φ is the temperature coefficient;

[0082] x is the vector group corresponding to the working condition, x = (N i , M i , T i );

[0083] Among them, N i is the rotational speed under the i-th working condition, M i is the load under the i-th working condition, T i is the intake air temperature under the i-th working condition, and i is a natural number greater than 0 and less than or equal to n;

[0084] c is the center point of the Gaussian kernel function;

[0085] σ is the bandwidth of the Gaussian kernel function.

[0086] In this embodiment, the kernel function is set as a Gaussian kernel function. The Gaussian kernel function has the characteristics that the higher the dimension, the more complex the model and the higher the accuracy. The boundary of the Gaussian kernel function is more complex and diverse, and can accurately distinguish data samples.

[0087] It is understandable that c is any one of all the determined operating conditions in step S1. Under this operating condition, the temperature coefficient is 1; the value of σ can be arbitrarily selected.

[0088] In one embodiment, different Gaussian kernel functions are determined according to different values of c and σ. The theoretical temperature coefficient is calculated based on the Gaussian kernel function determined for each group of c and σ. The variance between a group of theoretical temperature coefficients and the actual temperature coefficients under the corresponding operating conditions is calculated. The group of c and σ with the smallest variance is selected, and the corresponding Gaussian kernel function is determined and designated as the Gaussian kernel function of the temperature coefficient. For each operating condition of the engine, the corresponding temperature coefficient can be obtained based on the Gaussian kernel function of the temperature coefficient.

[0089] In one embodiment, different Gaussian kernel functions are determined according to different values of c and σ. The likelihood of all Gaussian kernel functions is calculated, and the Gaussian kernel function corresponding to the smallest absolute value of the likelihood is selected and designated as the Gaussian kernel function of the temperature coefficient. For each operating condition of the engine, the corresponding temperature coefficient can be obtained based on the Gaussian kernel function of the temperature coefficient.

[0090] In one embodiment, the kernel function of the temperature coefficient with respect to the vector group is a linear kernel function.

[0091] Exemplarily, please refer to Figure 4 , the steps of obtaining the corresponding ignition retard angle according to the base ignition angle, retard angle coefficient, and temperature coefficient corresponding to each determined operating condition include:

[0092] The ignition retard angle is determined according to the first correction angle and the second correction angle; the first correction angle is the product of the base ignition angle, the temperature coefficient, and the retard angle coefficient, and the second correction angle is the correction angle of the base ignition angle when the gas discharged from the engine passes through the exhaust gas treatment system.

[0093] In this embodiment, due to the presence of the exhaust gas treatment system in the engine system, the second correction angle is introduced. The exhaust gas treatment system will cause a change in the intake air temperature in the engine, thereby affecting the ignition retard angle. Therefore, to obtain a better ignition retard angle, the influence generated by the exhaust gas treatment system needs to be considered during calibration.

[0094] It should be noted that the second correction angle can be obtained by substituting the determined operating condition into the base ignition angle compensation map.

[0095] It is understandable that the second correction angle is a known quantity that can be read by the controller.

[0096] It should be noted that the second correction angle can be stored in the memory for the controller to call.

[0097] Exemplarily, when the gas discharged from the engine passes through the exhaust gas treatment system, the intake air temperature is equal to the temperature after the turbine minus the intercooler loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature, plus the exhaust gas treatment system outlet temperature.

[0098] In this embodiment, for the case where the gas discharged from the engine passes through the exhaust gas treatment system, the intake air temperature of the engine is corrected, so as to obtain a more accurate intake air temperature and improve the accuracy of calibrating the ignition retard angle.

[0099] It should be noted that the temperature after the turbine is the temperature when the gas discharges from the engine turbine; the intercooler loss temperature is the temperature change of the gas passing through the intercooler; the intake pipe dissipation temperature is the temperature change of the gas passing through the pipe between the intercooler and the throttle; the throttle throttle loss temperature is the temperature change of the gas passing through the throttle.

[0100] Exemplarily, please refer to Figure 3 , when the gas discharged from the engine does not pass through the exhaust gas treatment system, the ignition retard angle is the product of the base ignition angle and the retard coefficient and the temperature coefficient.

[0101] In this embodiment, the gas discharged from the engine does not pass through the exhaust gas treatment system, and the ignition retard angle is directly calibrated by the retard coefficient and the temperature coefficient.

[0102] Exemplarily, when the gas discharged from the engine does not pass through the exhaust gas treatment system, the intake air temperature is equal to the temperature after the turbine minus the intercooler loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature.

[0103] In this embodiment, the gas discharged from the engine does not pass through the exhaust gas treatment system, and the intake air temperature of the engine is directly determined by the temperature after the turbine, the intercooler loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature.

[0104] The second aspect of the embodiments of the present application provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the ignition retard calibration method of the engine in any of the above embodiments.

[0105] In one embodiment, the storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disc, or CD-ROM, or may also include various devices including one or any combination of the above memories.

[0106] The third aspect of the embodiments of the present application provides a powertrain 1, please refer to Figure 2 , the powertrain 1 includes a memory 10 and a processor 11. The memory 10 is configured to store a computer program. The processor 11 is configured to execute the stored computer program to implement the ignition retard calibration method of the engine in any of the above embodiments.

[0107] In this embodiment, the processor 10 of the powertrain 1 can implement a method for calibrating the ignition retard angle based on the engine speed, load, and intake air temperature. Corresponding temperature coefficients are obtained through multiple determined engine operating conditions. The ignition retard angle calibration is completed by using the temperature coefficient, the retard angle coefficient at a specific temperature, and the base ignition angle. This avoids the need to repeatedly calibrate the ignition retard angle using a combustion analyzer and a knock speaker when performing temperature correction on the ignition retard angle. The implementation scheme of this application does not require a large number of repetitive tests to complete the temperature correction of the ignition retard angle, improving the calibration efficiency.

[0108] In a fourth aspect of the embodiments of this application, a vehicle is provided. The vehicle includes a vehicle body and the powertrain 1 of the above embodiment. The powertrain 1 is installed on the vehicle body.

[0109] In one embodiment, the computer program can be in the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and can be deployed in any form, including being deployed as an independent program or being deployed as a module, component, subroutine, or other unit suitable for use in a computer environment.

[0110] Exemplarily, the computer program may or may not correspond to a file in the file system and can be stored as part of a file that stores other programs or data. For example, it can be stored in one or more scripts in a Hyper Text Markup Language (HTML) document, stored in a single file dedicated to the program being discussed, or stored in multiple cooperating files.

[0111] Exemplarily, the computer program can be deployed to be executed on one computing device, or on multiple computing devices located at one location, or on multiple computing devices distributed at multiple locations and interconnected by a network.

[0112] As described above, the foregoing are only the preferred embodiments of this application and are not intended to limit this application. For those skilled in the art, various changes and modifications can be made to this application. All modifications, equivalent replacements, improvements, etc. within the spirit and principle of this application are included within the protection scope of this application.

Claims

1. A method for calibrating the ignition angle retard, characterized in that including: determining a plurality of operating conditions of the engine according to the intake air temperature of the engine, the load of the engine, and the rotational speed of the engine; obtaining a corresponding temperature coefficient for each of the determined operating conditions according to all the determined operating conditions; acquiring a corresponding basic ignition angle and retard angle coefficient for each preset operating condition, where the preset operating condition is the operating condition corresponding to the initial intake air temperature among all the determined operating conditions; obtaining a corresponding retard ignition angle for the operating condition corresponding to the load and the rotational speed at different intake air temperatures according to the corresponding basic ignition angle and retard angle coefficient for each preset operating condition and the temperature coefficient for the operating condition corresponding to the load and the rotational speed at different intake air temperatures; wherein obtaining a corresponding temperature coefficient for each of the determined operating conditions according to all the determined operating conditions includes: determining a corresponding vector group according to each of the operating conditions of the engine; determining a kernel function of the temperature coefficient with respect to the vector group according to all the determined operating conditions; determining the temperature coefficient corresponding to each vector group according to the kernel function.

2. The calibration method according to claim 1, characterized in that The kernel function of the temperature coefficient with respect to the vector group is a Gaussian kernel function: wherein, Φ is the temperature coefficient; x is the vector group corresponding to the operating condition, x = (Ni, Mi, Ti); wherein, Ni is the rotational speed at the i-th operating condition, Mi is the load at the i-th operating condition, Ti is the intake air temperature at the i-th operating condition, and i is a natural number greater than 0 and less than or equal to n; c is the center point of the Gaussian kernel function; σ is the bandwidth of the Gaussian kernel function.

3. The calibration method according to any one of claims 1 to 2, characterized in that, Obtaining a corresponding retard ignition angle according to the corresponding basic ignition angle, retard angle coefficient, and temperature coefficient for each determined operating condition includes: determining the retard ignition angle according to a first correction angle and a second correction angle; the first correction angle is the product of the basic ignition angle, the temperature coefficient, and the retard angle coefficient, and the second correction angle is the correction angle for the basic ignition angle when the gas discharged from the engine passes through the exhaust gas treatment system.

4. The calibration method according to claim 3, wherein When the gas discharged from the engine passes through the exhaust gas treatment system, the intake air temperature is equal to the temperature after the turbine minus the intercooling loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature, and then plus the exhaust gas treatment system outlet temperature.

5. The calibration method according to any one of claims 1 to 2, characterized in that, When the gas discharged from the engine does not pass through the exhaust gas treatment system, the retard ignition angle is the product of the basic ignition angle and the retard angle coefficient and the temperature coefficient.

6. The calibration method according to claim 5, wherein When the gas discharged from the engine does not pass through the exhaust gas treatment system, the intake air temperature is equal to the temperature after the turbine minus the intercooling loss temperature, the intake pipe dissipation temperature, and the throttle throttle loss temperature.

7. A storage medium, on which a computer program is stored, characterized in that, When the computer program is executed by a processor, it implements the method for calibrating the retard ignition angle according to any one of claims 1 to 6.

8. A powertrain, characterized in that, including: a memory configured to store a computer program; a processor configured to execute the stored computer program to implement the method for calibrating the retard ignition angle according to any one of claims 1 to 6.

9. An automobile, characterized in that, including: a vehicle body; a powertrain as claimed in claim 8, the powertrain being installed on the vehicle body.

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