JP5447446B2 - Abnormal combustion detection device and internal combustion engine control device - Google Patents

Description

  The present invention relates to an abnormal combustion detection device that detects abnormal combustion of an internal combustion engine, and an internal combustion engine control device that includes the abnormal combustion detection device.

  As a means for detecting abnormal combustion of an internal combustion engine, a method of detecting abnormal combustion of an internal combustion engine by attaching a vibration sensor to the internal combustion engine and analyzing a waveform from the vibration sensor is known (see Patent Document 1). Although Patent Document 1 describes a detection method, it does not describe a specific circuit configuration for acquiring a waveform from a vibration sensor.

Japanese translation of PCT publication No. 2008-524489 JP-A-5-340331

  For example, in a supercharged small engine, in order to reliably acquire the waveform output from the vibration sensor, it is necessary to acquire from the waveform due to normal combustion to the waveform due to abnormal combustion that is about 40 times that of normal combustion. When detecting abnormal combustion using one AD converter circuit, it is necessary to fit the waveform (input voltage) in the input range range of the AD converter circuit. It must be set small (for example, 1/40 times). For this reason, since the waveform by small abnormal combustion will become small, the subject that detection of small abnormal combustion becomes difficult arises.

As a method for solving such a problem, a gain switching method (see Patent Document 2), a method using a high-resolution AD converter circuit, and a separate AD converter circuit are used to determine large abnormal combustion and small abnormal combustion. Although the method can be easily considered, since the gain switching method switches the gain after detecting the size of the waveform, a gain switching delay time occurs, and the gain follows when the waveform changes drastically every abnormal combustion judgment period There is a problem that the abnormal combustion of a minute waveform cannot be detected correctly.
On the other hand, since it is necessary to accurately reproduce the waveform so that it can be distinguished from the noise component, a high-speed (for example, 1 MHz sampling) and high-resolution (for example, 16-bit) AD conversion circuit is used. There is also a problem that it is very expensive to use a higher resolution product and two AD conversion circuits.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to detect an abnormal combustion of an internal combustion engine by converting a waveform output from a vibration sensor into digital data by an AD conversion circuit. It is an object of the present invention to provide an abnormal combustion detection device and an internal combustion engine control device that can detect a large abnormal combustion exceeding the input range range from a small abnormal combustion within the input range range.

  Since the waveform due to small abnormal combustion needs to be accurately distinguished from the waveform due to normal combustion and the waveform due to noise, it is necessary to accurately reproduce the waveform, but the large amplitude waveform due to large abnormal combustion is evident from the magnitude of the amplitude Can be judged abnormal. Therefore, according to the first aspect of the present invention, the gain is set appropriately so that normal combustion can be compared with small abnormal combustion, and large abnormal combustion is specified with a large amplitude waveform exceeding the input range of the AD converter circuit. . Accordingly, it is not necessary to prepare separate AD conversion circuits for determining large abnormal combustion and small abnormal combustion, so that abnormal combustion detection can be realized at low cost.

According to the invention of claim 2, it is possible to prevent erroneous determination due to noise that instantaneously exceeds a certain amplitude.
Since it is known that the waveform due to abnormal combustion output from the vibration sensor mainly includes frequency components of a predetermined frequency or lower, for example, 23 KHz or lower, frequency components exceeding 23 KHz other than this frequency component are determined as noise. Then, it is removed by a filter, and abnormal combustion detection is performed with a waveform having only a frequency component of 23 KHz or less. In this case, when a waveform exceeding the input range of the AD conversion circuit is input to the AD conversion circuit, the waveform of the excess portion is cut by the protection diode, so that the frequency component output from the filter is shifted. According to the invention of claim 3, it is possible to prevent the abnormal combustion from being judged by the data erroneously converted into different frequency components by the filter.

According to the invention of claim 4, when the peak of the waveform input to the AD converter circuit coincides with the upper limit value of the input range range, the peak of the waveform is in contact with the upper limit value of the input range range, for example. However, even in such a case, it can be reliably detected that the input range of the AD converter circuit is exceeded.
According to the invention of claim 5, since the maximum frequency of the waveform that can be generated by abnormal combustion (for example, 23 KHz) is detected in a minimum time that can be regarded as being equal to or higher than a certain voltage or less than a certain voltage, It is possible to reliably detect that the waveform that can be generated by abnormal combustion is equal to or higher than a certain voltage or less than a certain voltage, and to prevent erroneous determination due to instantaneous noise.
According to the invention of claim 6, since the large abnormal combustion is spontaneous ignition and occurs earlier than the optimal combustion timing, the ignition timing of the internal combustion engine is detected by detecting the crank angle at the timing when the large abnormal combustion occurs. Can be appropriately controlled.

According to the seventh aspect of the present invention, high-frequency noise is removed by the analog filter, and the AD conversion circuit and the detection circuit are arranged at the subsequent stage, so that the same waveform as that input to the AD conversion circuit is input to the detection circuit. Therefore, it is possible to reliably detect that the waveform input to the AD converter circuit is equal to or higher than a certain voltage or less than a certain voltage.
According to the eighth aspect of the invention, even when the reference voltage of the AD converter circuit is shifted, the detection threshold value of the detection circuit is also shifted in the same manner. It can be detected that the voltage is below a certain voltage.
According to invention of Claim 9, an internal combustion engine can be controlled appropriately according to the magnitude | size of abnormal combustion.

The block diagram which shows the structure of the engine control apparatus in one Embodiment of this invention. Functional block diagram showing an integrated circuit The figure explaining overrange detection when the top of the waveform matches the overrange detection threshold The figure which shows the relationship between the frequency of an input waveform of an AD converter circuit, and an amplitude Diagram showing abnormal combustion signal Flow chart showing abnormal combustion determination period setting process Flow chart showing abnormal combustion determination processing Flow chart showing overrange detection process

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of the engine control apparatus. The engine control device 1 (corresponding to an abnormal combustion detection device or internal combustion engine control device) controls a 4-cylinder gasoline engine (corresponding to an internal combustion engine).
A vibration sensor 2 is attached to a cylinder block of an engine (not shown). The vibration sensor 2 is a sensor that detects vibration of the cylinder block and outputs a signal corresponding to vibration of the cylinder block (hereinafter referred to as abnormal combustion signal) when abnormal combustion is detected. Based on the magnitude of the waveform of this abnormal combustion signal, the magnitude of combustion, that is, whether it is a small abnormal combustion or a large abnormal combustion is determined. Small abnormal combustion (knock) is a part of the gas mixture in the combustion chamber where the mixture of fuel and air is not uniform (especially where the fuel is concentrated, etc.) The cylinder block vibrates due to abnormal combustion that causes self-ignition in the non-uniform part before it is propagated by the spark plug ignition. It is a phenomenon. Large abnormal combustion (pre-ignition) is abnormal combustion in which the carbon inside the engine becomes red-hot due to combustion before ignition with the spark plug or the spark plug itself overheats due to a heat spot (heat source) overheated This is a phenomenon in which the cylinder block vibrates due to the above.

  The abnormal combustion signal from the vibration sensor 2 is connected to the engine control device 1 via the connector 3 and passes a high-frequency signal component corresponding to the abnormal combustion signal out of the input signal and includes an unnecessary low signal including a DC component. A frequency signal component (for example, 5 kHz or less) is removed, and the signal input from the input circuit 4 is input to the input circuit 4 that converts 2.5V into a center signal. The signal is amplified or attenuated by a factor of 1/5 and then applied to the integrated circuit 6. The integrated circuit 6 comprises an analog filter 7, an AD conversion circuit 8, a digital filter 9, an overrange detection circuit 10 (corresponding to a detection circuit), and a crank timer 11, and the processed data is sent to an engine control microcomputer 12 (determination). To the crank angle detecting means).

  On the other hand, a crank sensor 13 is attached to the engine, and a pulse signal is output to the crank timer 11 every time the crankshaft rotates by a predetermined crank angle (for example, 180 °). The crank timer 11 detects a period between TDCs from the compression stroke top dead center (hereinafter referred to as TDC) to the next TDC based on a signal from the crank sensor 13 and outputs the detected period to the engine control microcomputer 12.

  The engine control microcomputer 12 includes a CPU 14, a ROM (not shown), a RAM, and the like. By executing various engine control programs stored in the ROM, the fuel injection amount of the fuel injection valve, fuel injection timing, ignition Controls ignition timing of plug, opening timing of intake valve and exhaust valve, and the like. Further, the engine control microcomputer 12 estimates the crank angle based on the TDC timing based on the period between the TDCs, and sets the period during which the estimated crank angle is a predetermined range angle as the abnormal combustion determination period. In this embodiment, the period from the timing before -20 ° CA of the TDC timing of each cylinder (timing of BTDC 20 ° CA) to the timing after 70 ° CA of the TDC timing (ATDC 70 ° CA timing) is the abnormal combustion determination section. Is set.

  FIG. 2 is a functional block diagram of the integrated circuit 6. The analog filter 7, the AD conversion circuit 8 and the overrange detection circuit 10 connected in parallel to the subsequent stage of the analog filter 7, and the digital circuit connected to the subsequent stage of the AD conversion circuit 8. A filter 9 is included. In front of the analog filter 7, the other ends of the protection diodes 17 and 18 for clamping, each of which is connected to the internal power supply line 15 and the internal ground line 16, are connected, and the internal power supply potential (constant voltage) is connected to the analog filter 7. If a waveform exceeding the ground potential (corresponding to a certain voltage) is input, the waveform is clamped to the internal ground potential.

  The abnormal combustion signal output from the vibration sensor 2 is an input that passes a high-frequency signal component corresponding to the abnormal combustion signal, removes an unnecessary low-frequency signal component including a DC component, and converts 2.5 V into a central signal. It is input to the circuit 4 and mainly includes a signal component of 23 KHz or less as an abnormal combustion component. The analog filter 7 is an anti-aliasing filter for the purpose of eliminating aliasing with respect to 1 MHz sampling by the AD conversion circuit 8, and the cutoff frequency is set to 318 KHz. The AD conversion circuit 8 has a resolution of 16 bits, and the sampling frequency is 1 MHz. The reason why the sampling frequency is set to 1 MHz in this way is that the attenuation of the signal band of 23 KHz or less is set by setting the sampling frequency to be sufficient oversampling with respect to 23 KHz which is the maximum frequency included in the abnormal combustion signal. This is to suppress the aliasing noise as well as to suppress it. The digital filter 9 is provided for the purpose of removing aliasing from decimation and reducing noise by Nyquist frequency (1/2 of the sampling frequency) by oversampling, and the pass band is set to 23 KHz or less.

  The overrange detection circuit 10 is for detecting whether the input level to the AD conversion circuit 8 exceeds a predetermined overrange detection threshold, and includes a first comparison circuit 19, a second comparison circuit 20, and an AND circuit 21. It is composed of The overrange detection threshold value is a threshold value for detecting that the input range range of the AD conversion circuit 8 has been exceeded. Originally, it should be set to the upper limit value and the lower limit value of the input range range of the AD conversion circuit 8. However, if the overrange detection threshold value is matched with the upper limit value and lower limit value of the input range range of the AD conversion circuit 8, a problem as described later occurs. Therefore, in this embodiment, the overrange detection threshold value is AD converted. It was set to 4.4 V and 0.6 V within the input range of the circuit 8. That is, a reference voltage of 4.4 V (corresponding to the overrange detection threshold) is connected to the non-inverting input terminal of the first comparison circuit 19, and the output side of the analog filter 7 is connected to the inverting input terminal. The non-inverting input terminal of the second comparison circuit 20 is connected to the output side of the analog filter 7, and a reference voltage of 0.6 V (corresponding to the overrange detection threshold) is connected to the inverting input terminal. As these reference voltages, as shown in FIG. 2, a reference voltage generated by an internal resistor 22 connected in series inside the AD conversion circuit 8 is used. The number of internal resistors 22 shown in FIG. 2 is different from the actual number.

  The output terminals of the first comparison circuit 19 and the second comparison circuit 20 are connected to the input terminal of the AND circuit 21, and the output terminal of the AND circuit 21 is connected to the engine control microcomputer 12. With such a configuration, the overrange detection circuit 10 outputs a high level signal when the signal level of the abnormal combustion signal input to the AD conversion circuit 8 is 0.6 V to 4.4 V, and is 4.4 V or higher or When the voltage is 0.6 V or less, a low level signal is output. Therefore, it is possible to detect an overrange by detecting that a low level signal is output.

Here, the concept of overrange detection by the overrange detection circuit 10 will be described. Since the input range of the AD converter circuit 8 is 0.5 to 4.5 V, which is ± 2 V centered on 2.5 V, for example, an upper limit value of 4.5 V is set as the overrange detection threshold, and 4.5 V A signal level exceeding 1 may be detected as an overrange. However, in such a case, when the peak of the waveform input to the AD conversion circuit 8 is 4.5 V which is the overrange detection threshold as shown in FIG. 3, the input waveform is the overrange detection threshold. The overrange detection becomes unstable. Therefore, in the present embodiment, overrange detection is performed for 4.4 V or more, or 0.6 V or less (2.5 center ± 1.9 V), which is 95% of the ± 2 V amplitude of 2.5 V, which is the center level of the abnormal combustion signal. It was set as a threshold value. As a result, even if the apex of the input waveform to the AD conversion circuit 8 is the upper limit value or the lower limit value of the input range range, it is possible to stably detect the overrange. In this case, the time over which the 2.5 V center ± 2 V waveform is equal to or greater than the overrange detection threshold is set to Arc Sin (V / Vpeak) / π = 20% with an amplitude ratio of 95% (corresponding to a constant amplitude) or more. In this case, the duration time T = 1/23 KHz (knock MAX frequency) / 2 (half cycle) × 20% = 4.3 μs (corresponding to a predetermined time) can be obtained. That is, it may be determined that an overrange is detected on condition that the amplitude is 1.9 V or more for 4.3 μs. In this case, a waveform with a frequency of 23 KHz or less over the input range (4.5 V or more or 0.5 V or less) has a detection threshold of 4.4 V or more or 0.6 V or less for 4.3 μs or more. Therefore, the frequency of abnormal combustion of 23 KHz or less corresponding to abnormal combustion can be detected.

  FIG. 4 is a diagram showing the relationship between the frequency and amplitude of the input waveform of the AD converter circuit 8 that is 4.4 V or more or 0.6 V or less for a time of 4.3 μ or more. In the drawing, the hatched area is an area where the overrange detection circuit 10 detects an overrange, and the other areas are areas where no overrange is detected. Among the areas indicated by diagonal lines, the areas indicated by right diagonal lines continue to be 4.3 V or higher or 0.6 V or lower for a period of 4.3 μ or more, and the areas indicated by left diagonal lines represent other noise. This is a region erroneously detected as overrange detection. Therefore, it is determined that a waveform exceeding the input range range has been input to the AD conversion circuit 8 by detecting that the time when the signal output from the overrange detection circuit 10 is at a low level is 4.3 μm or more. be able to.

The engine control microcomputer 12 sets an abnormal combustion determination period in order to determine the magnitude of abnormal combustion from the waveform of the abnormal combustion signal.
FIG. 6 is a flowchart showing an abnormal combustion determination period setting process by the engine control microcomputer 12. When the engine control microcomputer 12 inputs a period between TDCs, that is, a time during which the crank rotates 180 ° from the crank timer 11 (S601: YES), the engine control microcomputer 12 rotates 5 ° CA time, that is, the crank rotates 5 ° based on the TDC time. The time to perform is calculated (S602). Next, a period of −20 ° CA (BTDC 20 °) to 70 ° CA (ATDC 70 °) is set as an abnormal combustion determination period based on the TDC timing (S603).

  FIG. 7 is a flowchart showing abnormal combustion determination processing by the engine control microcomputer 12. When the engine control microcomputer 12 determines that it is the start of the abnormal combustion determination period set as described above (S701: YES), the engine control microcomputer 12 determines whether the sun printer im of the AD conversion circuit 8 has been reached (S702). When it becomes (S702: YES), the overrange detection circuit 10 detects the overrange, that is, determines whether the detection signal from the overrange detection circuit 10 is at a low level (S703). When the overrange is not detected (S703: NO), the digital data output from the AD conversion circuit 8 is repeatedly accumulated (S704, S705). When 5 ° CA time has elapsed (S705: YES), it is determined that the crank has rotated 5 °, and the integrated value is stored (S706).

  The engine control microcomputer 12 repeatedly executes the above-described operation. When the abnormal combustion determination period ends (S707: YES), the engine control microcomputer 12 determines abnormal combustion (S708). That is, as described above, since the digital data for each sampling time of BTDC 20 ° to ATDC 70 ° is accumulated and stored every 5 ° CA, abnormal combustion can be determined from the level of the accumulated value. When abnormal combustion is detected as a result of the determination of abnormal combustion (S709: YES), the size of the waveform is determined (S710).

FIG. 5 shows an abnormal combustion signal output from the vibration sensor 2. The abnormal combustion indicated by the abnormal combustion signal can be classified into small abnormal combustion and large abnormal combustion. Furthermore, large abnormal combustion may occur when the waveform is within the input range range of the AD conversion circuit 8 or beyond the input range range. In this abnormal combustion determination process, within the input range range of the AD conversion circuit 8. Determine the magnitude of abnormal combustion. That is, when the waveform amplitude is large (S710: large), the engine control microcomputer 12 identifies a large abnormal combustion (S711), identifies the crank angle (S712), and when the waveform amplitude is small (S710: Small), after identifying a small abnormal combustion (S713), the crank angle is identified (S714).
The engine control microcomputer 12 controls the ignition timing of the engine and the fuel injection amount based on the magnitude of abnormal combustion specified as described above.

On the other hand, the engine control microcomputer 12 executes an overrange detection process. FIG. 8 is a flowchart showing overrange detection processing by the engine control microcomputer 12. The engine control microcomputer 12 has a detection signal from the overrange detection circuit 10 at a low level, that is, when the waveform input to the AD conversion circuit 8 is equal to or higher than a predetermined voltage of 4.4V or higher or equal to or lower than 0.6V. (S801: YES), the detection time is measured (S802), and it is determined whether the detection time is 4.3 μs or more (S803). When it is 4.3 μs or longer (S803: YES), an overrange is detected (S804).
The engine control microcomputer 12 controls the ignition timing of the engine and the fuel injection amount based on the large abnormal combustion specified as described above.

  By the way, the protective diodes 17 and 18 for clamping are provided in the input stage of the integrated circuit 6, and when the voltage exceeding the input range of the AD converter circuit 8 is input, the value of the range boundary of the input voltage is output. Therefore, when the waveform input to the AD conversion circuit 8 exceeds the input range range, the overranged input waveform is clamped to the internal power supply potential or the internal ground potential, and the waveform of that portion is deleted. For this reason, the frequency component input to the AD conversion circuit 8 shifts, and abnormal combustion is determined based on the digital data erroneously converted to a different frequency component by the digital filter 9. Therefore, in this embodiment, when the overrange detection circuit 10 detects an overrange in the abnormal combustion determination of FIG. 7 (S703: YES), the engine control microcomputer 12 moves the data to step S707. I tried not to use it. Thereby, the engine control microcomputer 12 can accurately determine the magnitude of abnormal combustion based on the digital data even when the frequency component of the waveform input to the AD conversion circuit 8 is shifted.

According to such an embodiment, the magnitude of abnormal combustion is determined based on the digital data output from the AD conversion circuit 8, and a large abnormal combustion is identified when the overrange detection circuit 10 detects an overrange. Thus, it is not necessary to prepare separate AD conversion circuits for determining large abnormal combustion and small abnormal combustion, and abnormal combustion detection can be realized at low cost.
When a waveform exceeding the input range is input to the AD converter circuit 8, the waveform of the exceeding portion may be deleted by the protection diodes 17 and 18, or the value of the input voltage range boundary may be output. It is possible to prevent abnormal combustion calculation using digital data that has been erroneously converted into different frequency components by the filter 9.

Since the overrange detection threshold is set to 4.4 V or 0.6 V within the input range range of the AD converter circuit 8, the peak of the waveform input to the AD converter circuit 8 is 4.5 V, which is the upper limit value of the input range range. Even if the overrange detection becomes unstable due to the coincidence, it can be reliably detected that the input range of the AD conversion circuit 8 is exceeded.
Since the overrange is detected at 4.3 μs, which is the minimum time that can be regarded as being overranged at 23 KHz, which is the maximum frequency of the waveform that can be generated by abnormal combustion, the waveform that can be generated by abnormal combustion is It is possible to reliably detect overrange and to prevent erroneous determination due to instantaneous noise.

Since the crank angle at the timing at which the overrange is detected is detected, the ignition timing of the engine can be appropriately controlled even if a large abnormal combustion occurs earlier than the optimal combustion timing.
The analog filter 7 removes high frequency noise, and the AD conversion circuit 8 and the overrange detection circuit 10 are arranged at the subsequent stage, so that the same waveform as the waveform input to the AD conversion circuit 8 is input to the overrange detection circuit 10. As a result, the overrange of the waveform input to the AD conversion circuit 8 can be reliably detected.
Since the reference voltage generated inside the AD conversion circuit 8 is used as the detection threshold value of the overrange detection circuit 10, the detection threshold value of the overrange detection circuit 10 even when the reference voltage of the AD conversion circuit 8 is shifted. Therefore, the overrange can be detected without affecting the deviation of the reference voltage of the AD conversion circuit 8.

(Other embodiments)
The overrange detection threshold value of the overrange detection circuit 10 may be arbitrarily set as long as it is within the input range range of the AD conversion circuit 8.
The overrange range detection threshold of the overrange detection circuit 10 may be set to the upper limit value of the input range range of the AD conversion circuit 8.
A protective diode and a filter may be provided as appropriate.

  In the drawings, 1 is an engine control device (abnormal combustion detection device, internal combustion engine control device), 2 is a vibration sensor, 5 is a gain circuit, 6 is an integrated circuit, 7 is an analog filter, 8 is an AD converter circuit, and 9 is a digital filter. Reference numeral 10 denotes an overrange detection circuit (detection circuit), 12 denotes an engine control microcomputer (determination means, crank angle detection means), and 17 and 18 denote protection diodes.

Claims (9)

In an abnormal combustion detection device that detects abnormal combustion by a waveform output from a vibration sensor attached to an internal combustion engine ,
A gain circuit that amplifies or attenuates the waveform output from the vibration sensor;
An AD conversion circuit for converting the waveform output from the gain circuit into digital data;
A circuit for detecting that the waveform input to the AD converter circuit is equal to or higher than a certain voltage or less than a certain voltage;
Abnormal combustion is determined based on the digital data output from the AD conversion circuit, and when the detection circuit detects a voltage that is greater than or equal to a certain voltage , the waveform that is input to the AD conversion circuit is the waveform of the AD conversion circuit. Determining means for determining that the combustion is large and exceeding the input range ,
An abnormal combustion detection device comprising:   The abnormal combustion detection device according to claim 1, wherein the detection circuit detects the voltage equal to or higher than the predetermined voltage or lower than the predetermined voltage when a waveform having a predetermined amplitude or more is detected for a predetermined time or longer. A digital filter that removes a frequency component of a specific frequency or more from the digital data output from the AD converter circuit; a protection diode that clamps a waveform that exceeds or falls below a certain voltage input to the AD converter circuit to a predetermined voltage; Configured as an integrated circuit with
3. The abnormal combustion detection according to claim 2, wherein the determination unit does not use the digital data output from the AD conversion circuit as the determination of abnormal combustion when the detection circuit detects the predetermined amplitude or more. apparatus.   The abnormal combustion detection device according to claim 2, wherein the constant amplitude is within an input range of the AD converter circuit. 5. The detection circuit according to claim 2, wherein the detection circuit determines that the waveform is equal to or greater than the predetermined amplitude when the waveform satisfies a duration T or more obtained by the following arithmetic expression. Abnormal combustion detection device.
T = Arc Sin (V / Vpeak) / π × {1 / (2 × f)}
f: Frequency = Maximum frequency that can occur due to abnormal combustion V: Detection range exceeding input range Vpeak: Upper limit of input range Crank angle detection means for detecting the crank angle of the internal combustion engine,
6. The abnormal combustion detection device according to claim 2, wherein the crank angle detection unit detects a crank angle at a timing when the detection circuit detects a waveform having a certain amplitude or more. An analog filter for inputting a waveform from the vibration sensor;
The abnormal combustion detection device according to claim 1, wherein the AD conversion circuit and the detection circuit are provided in parallel at a subsequent stage of the analog filter.   The abnormal combustion detection device according to claim 2, wherein a reference voltage generated inside the AD conversion circuit is used for the constant amplitude. The abnormal combustion detection device according to any one of claims 1 to 8,
An internal combustion engine control device that controls a fuel injection amount, a fuel injection timing, an ignition timing of a spark plug, and the like of the internal combustion engine according to the magnitude of abnormal combustion detected by the abnormal combustion detection device.

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