JPH0579441A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] Whether or not the internal combustion engine is manufactured, the manufacturing variations, and the secular change make it possible to accurately determine whether knocking has occurred. [Structure] When determining the presence or absence of knocking of the internal combustion engine based on the analysis result of the vibration data of the internal combustion engine, the first vibration data of the internal combustion engine in the ignition timing range in which it is determined that knocking has not occurred, and knocking have occurred. And the second vibration data of the internal combustion engine in the ignition timing range determined to be stored in the storage device, the difference or ratio between the two is calculated, and the difference or ratio is taken to detect the knocking characteristic. And so on. Then, it is determined whether or not this knocking characteristic appears for each ignition cycle, and the average of the determined data and the past data (first vibration data or second vibration data) is calculated to obtain new past data. To do.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device for retarding the ignition timing when knocking occurs during ignition of an internal combustion engine to suppress the occurrence of knocking. The present invention relates to an ignition timing control device for an internal combustion engine, which is suitable for accurately determining the presence or absence of knocking.

[0002]

2. Description of the Related Art When controlling the ignition timing of an internal combustion engine, the ignition timing is advanced to the minimum ignition timing at which knocking does not occur. However, the degree of advancement at which knocking does not occur cannot be unconditionally determined because it depends on the type of each internal combustion engine, manufacturing variations, and cylinders. Therefore, conventionally, an internal combustion engine is driven in advance on a trial basis at a required ignition timing, a physical vibration generated in the explosion stroke of the internal combustion engine is detected by a vibration sensor, and knocking is detected from the vibration data. Is determined and the limit on the advance side of the ignition timing of the internal combustion engine is set.

However, the vibration of the internal combustion engine includes not only the vibration caused by the explosion of fuel but also the vibration called mechanical noise peculiar to the internal combustion engine. If this mechanical noise is mistaken as knocking, accurate measurement cannot be performed. I will end up. Therefore, conventionally, for example, as described in Japanese Patent Application Laid-Open No. 58-45520, a frequency component unique to knocking, which does not include mechanical noise, of the vibration frequency is determined in advance,
Whether or not knocking has occurred is determined by whether or not this frequency component is present in the vibration data. In addition, JP-A-6
As described in Japanese Patent No. 1-222123, the vibration extraction period is changed according to the cylinder number to eliminate the influence of mechanical noise for each cylinder.

[0004]

SUMMARY OF THE INVENTION The above-mentioned prior art is
The frequency peculiar to knocking is determined in advance by a test,
Alternatively, the extraction engine that causes knocking is set in advance,
This is a test for determining the knocking characteristics of each internal combustion engine. For this reason, it is necessary to perform a test for each internal combustion engine, which requires a large number of man-hours, which is one of the reasons for increasing the cost. In addition, the frequency peculiar to knocking and the knocking occurrence period change with time, and the long-term ignition timing is fixedly controlled by the knocking detection frequency and the knocking extraction period experimentally obtained in the initial stage. If so, knocking will occur and good ignition timing control will become impossible.

An object of the present invention is to provide an ignition timing control device capable of coping with manufacturing variations and secular changes of individual internal combustion engines and capable of always performing good ignition timing control.

[0006]

DISCLOSURE OF THE INVENTION The object of the present invention is to knock in an ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on the analysis result of vibration data of the internal combustion engine to control the ignition timing. Means for determining the difference or ratio between the magnitude of the vibration component with respect to the crank angle of the internal combustion engine in the ignition timing range determined to be nonexistent and the magnitude of the vibration component with respect to the crank angle of the internal combustion engine in the ignition timing range determined to be knocking This is achieved by providing a means for determining the presence or absence of knocking based on whether or not the knocking characteristic represented by taking this difference or ratio is included in the vibration data obtained for each ignition of the internal combustion engine.

Further, the above-mentioned object is to obtain a frequency spectrum A by analyzing vibration data of the internal combustion engine in the ignition timing range in which it is determined that knocking has not occurred, and in the ignition timing range in which knocking has been determined. It is represented by means for analyzing the vibration data of the internal combustion engine to obtain the frequency spectrum B, means for obtaining the difference or ratio between the distribution of the frequency spectrum A and the distribution of the frequency spectrum B, and taking this difference or ratio. It is also achieved by providing a means for determining the presence or absence of knocking depending on whether or not the knocking characteristic is included in the vibration data obtained for each ignition of the internal combustion engine.

[0008]

According to the present invention, when the internal combustion engine is being driven, the vibration data in which knocking has not occurred and the vibration data in which knocking has occurred are accumulated, and both accumulated data are compared to determine the presence or absence of knocking. Find the knocking characteristics. The knocking characteristic is the magnitude of the vibration amplitude or the frequency spectrum, and the mechanical noise contained in both is removed by comparing the accumulated data of both. Further, changes in vibration data due to individual manufacturing variations of the internal combustion engine and changes over time can be eliminated by comparing the above two.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a configuration diagram of a control system for an internal combustion engine to which an ignition device according to an embodiment of the present invention is applied. Air enters from the inlet of the air cleaner 1, passes through a duct 3, a throttle body 5 having a throttle valve 5, an intake pipe 6, and is sucked into a cylinder of an internal combustion engine 7. The intake air amount is detected by an air flow sensor 2 such as a hot wire air flow meter provided in the duct 3, and a detection signal is sent to the control unit 9. On the other hand, the fuel is injected by the injector 16 and the fuel (air mixture) mixed with the intake air is supplied into the cylinder of the internal combustion engine 7. The air-fuel mixture is compressed in the cylinder, ignited by the spark plug 15, explodes and pushes down the piston (explosion stroke). In the next exhaust stroke, the exhaust gas in the cylinder is exhausted to the exhaust pipe 8.
An exhaust sensor 11 is provided in the exhaust pipe 8 and a detection signal is sent to the control unit 9.

The high voltage sent to the ignition plug 15 is generated in the ignition coil 13 and distributed by the distributor 14 to the ignition plug of each cylinder. The crankshaft connected to the piston of the internal combustion engine rotates by repeating the intake stroke, compression stroke, explosion stroke, and exhaust stroke in each cylinder of the internal combustion engine. This rotation state is determined by the crank angle sensor 12. The detected signals (REF signal and POS signal) are sent to the control unit 9. A vibration sensor 17 is attached to the internal combustion engine 7, and physical vibration data of the internal combustion engine 7 detected by the vibration sensor 17 is sent to the control unit 9. The vibration sensor 17 may detect a pressure fluctuation in the cylinder. The control unit 9 calculates the fuel injection amount, the ignition timing and the like based on the detection signal from each sensor and outputs the control signal to each actuator (injector 16 or the like).

FIG. 3 is a block diagram of the control unit. This control unit includes a CPU 20 and an A
/ D converter 21, input I / O 22, ROM 23,
The RAM 24 and the output I / O 25 are provided. The detection signal of the vibration sensor is A / D at a predetermined sampling interval.
It is converted into a digital signal by the converter 21 and taken into the CPU 20. The input I / O receives the REF signal and the POS signal from the crank angle sensor and gives them to the CPU 20. The CPU 20 processes these signals in accordance with the ignition timing control program and the fuel injection amount control program stored in the ROM 23, and outputs the ignition signal θign and the fuel injection signal Tp to each actuator via the output I / O 25.

FIG. 1 is an explanatory diagram of a knocking determination method in an ignition control device according to a first embodiment of the present invention. FIG. 1A is a comparison of the outputs of the vibration sensor at the time of non-advanced angle (a state in which knocking hardly occurs) and at the time of advanced angle (a state in which knocking occurs frequently). When advancing, the vibration component due to knocking increases in the first half of the combustion stroke, and the vibration component due to mechanical noise increases in the latter half. When the vehicle is not advanced, knocking does not occur, so there is no knocking vibration component, and mechanical noise occurs in the latter half. Figure 1
(B) is a graph in which the output of the vibration sensor is observed a plurality of times for each of the non-advanced angle and the advanced angle, and the magnitude of vibration with respect to the crank angle is graphed. The distribution of the vibration component represented by this graph is obtained by, for example, a method of obtaining the envelope of the vibration sensor output for a plurality of ignitions and averaging these. Comparing the distributions of the non-advanced angle (dotted line) and the advanced angle (solid line), it can be seen that there is a difference in the distribution of the portion in which the increase in the knocking component is large. Further, it can be seen that there is no difference in distribution at the timing when mechanical noise occurs. Therefore, while operating the internal combustion engine, both distributions are obtained, a section in which the difference between the two is clear is defined, and the presence or absence of knocking can be detected by whether or not the vibration component in this section is large. it can.

FIG. 1C is a graph showing the difference between the above two distributions. In the example shown in this figure, the crank angle is 2
It can be seen that the vibration due to knocking is large in the range of 12 degrees to 34 degrees centering on the position of 3 degrees. Therefore, the output of the vibration sensor when the crank angle is 12 degrees to 34 is taken, and the presence or absence of knocking is determined by whether or not the vibration level in this section is large. If it is determined that knocking is present, the ignition timing is delayed. When it is determined that there is no knocking, the ignition timing is advanced, and the ignition timing can be controlled immediately before the ignition timing at which knocking occurs.
Although the difference between the two distributions is obtained in FIG. 1C, the presence or absence of knocking can be similarly determined by obtaining the ratio of the two distributions.

FIG. 4 is a diagram for explaining the operation of the control unit 9 which determines the presence or absence of knocking as described above.
The POS counter 20a, compare register 20b, and comparator 20c shown in FIG. 4 may be provided as hardware in the control unit 9 shown in FIG. 3 or may be provided as software. Needless to say.

In this embodiment, the start time and the end time of the A / D conversion section sandwiching the detection section (12 degrees to 34 degrees) shown in FIG. 1C are defined by these three circuit elements 20a, 20b, 20.
It is configured to be controlled by c and the CPU 20. The POS counter 20a is, for example, a POS that is generated every 2 degrees of crank angle from the rising edge of the REF signal indicating the top dead center signal.
Count the rising edge of the signal. Compare register 20b
Under the control of the CPU 20, first, data (data converted into the number of POS signals) indicating the start time point of the A / D conversion section is stored. When the count value of the POS counter 20a reaches the A / D conversion start time point, the comparator 20
c outputs the coincidence signal of both to the CPU 20. Upon receipt of this match signal, the CPU 20 immediately receives the compare register 2
Data indicating the end point of A / D conversion is stored in 0b. Then, when the count value of the POS counter 20a reaches this end point, the comparator 20c outputs a coincidence signal to the CPU 20. The CPU 20 performs the processing described below by using these coincidence signals as interrupt signals.

FIG. 5 is a diagram for explaining the operation when the output signal of the vibration sensor is converted into digital data by the A / D converter 21 and taken into the CPU 20. The CPU 20 outputs a conversion start command to the A / D converter 21 when it receives the first interrupt signal from the comparator 20c, and outputs a conversion end command when it receives the next interrupt signal. The output signals of the vibration sensor converted into digital data at predetermined sampling intervals during this A / D conversion period are sequentially stored in the RAM 24. Based on the data stored in this RAM 24, the CP
U20 determines whether or not knocking has occurred.

FIG. 6 is a flowchart of the knocking determination process. First, the data of the detection section shown in FIG. 1 (c) that has already been set in the previous stroke is read. Here, the detection section is a constant value (for example, 22
Value section), and the value at the start of the detection section is read (step 100). In the next step 110, the data stored in the RAM 24 in this detection section is read and its frequency is analyzed to obtain the magnitude of the spectrum corresponding to the resonance frequency of knocking. Here, the frequency analysis method is, for example, FFT (First Fourier Tran).
sform) and WFT (Walsh to Fourier Transform). In step 120, the magnitude of the spectrum obtained in step 110 is compared with a predetermined value for knocking determination, and the presence or absence of knocking is determined.

Knocking Presence / Absence Judgment Processing (Step 1
After 20), the process for obtaining the next detection section shown in FIG. 1C is performed. Therefore, first, in step 130, RA
The data stored in M24 is smoothed. The concept of this smoothing is shown in FIG. First, the data stored in the RAM 24 is converted into an absolute value. The absolute value conversion is to invert the sign of a signal on the negative side with respect to a DC voltage component serving as an offset without changing the absolute value of its magnitude. This absolute valued data is smoothed. The smoothing is to divide the data string into predetermined sections and average the data in each section. By smoothing the data obtained for each of the multiple ignition cycles and averaging them,
Distribution data of the vibration component is obtained. The existing distribution data is updated with this newly obtained distribution data.

Therefore, in step 140, it is determined whether the newly obtained data is data with knocking or data without knocking. When there is no knocking, the routine proceeds to step 150, where the average value of the previously stored knocking-free distribution data for each crank angle and the new distribution data for this time for each crank angle is calculated. The distribution data based on the average value obtained in step 1 is stored (step 170a). When it is determined that knocking is present in step 140, the distribution data with knocking is similarly updated and stored (steps 160 and 170).
b). Then, the difference between the two distributions is obtained in step 180, and the next detection section shown in FIG. 1C is set (step 19
0), this processing is ended.

By performing the above processing for each ignition cycle, it is possible to accurately determine the presence or absence of knocking regardless of the type of the internal combustion engine, manufacturing variations, and secular change. It becomes possible to set.

FIG. 8 is a flow chart showing the processing procedure of the control method in the ignition timing control device according to the second embodiment of the present invention. In the present embodiment, the operating region of the internal combustion engine is divided into nine regions according to the load and the rotational speed (see FIG. 9), and the detection section shown in FIG. 1 (c) is defined for each region to determine the presence or absence of knocking. I am trying to do it. The process of determining the presence or absence of knocking in each region is the same as in the first embodiment described above. In this embodiment, first, it is determined which region in FIG. 9 the current operating region of the internal combustion engine is based on the rotational speed and the load. (Step 200). Then, the respective distribution data with and without knocking stored in the memory corresponding to the current operating region are read (step 210), and then the difference between the two is obtained and the operating region is shown in FIG. 1 (c). The place where the detection section to be shown is set, for example, as a section where the difference is a predetermined value or more (step 220).

In the next step 230, the vibration data in the ignition cycle to be judged is subjected to frequency analysis to judge the presence or absence of knocking as described above. Then, the previous data is updated with the newly obtained data (step 2
40-270). By performing these procedures for each ignition cycle and calculating the learning value of the distribution in each operating region, it is possible to accurately determine the presence or absence of knocking even when the operating region changes suddenly.

FIG. 10 is an explanatory diagram of knocking determination in the ignition timing control system according to the third embodiment of the present invention.
FIG. 10A is a graph comparing the spectral distributions of the vibration data at the time of non-advancement and at the time of advancement. Each spectrum distribution in FIG. 10A is obtained by averaging the values obtained from the frequency analysis in a plurality of ignition cycles. In the example shown in FIG. 10A, 9 kHz, 13 k
Differences appear at frequencies near Hz and 16 kHz. These are considered to be an increase in spectrum due to resonance vibration of knocking. On the other hand, although the spectrum value is large in the vicinity of 6 kHz, there is almost no difference in distribution, which is considered to be related to mechanical noise unrelated to knocking.
Therefore, if the spectrum around 6 kHz is used for determining whether knocking is present or not, it may cause an erroneous determination.

FIG. 10 (b) shows the ratio of both distributions in FIG. 10 (a). The distribution ratio has a large value at the frequency at which the spectrum increases due to the resonance vibration of knocking, and the distribution ratio has a value around 1 at the frequency of the spectrum due to mechanical noise. Therefore, it is possible to determine the presence or absence of knocking based on the correction value by calculating the weighting coefficient according to the distribution ratio and correcting the spectrum of the vibration data with this. An example of this weighting factor is shown in FIG. The value of the weighting coefficient is increased at a frequency where the distribution ratio is large, and the weight is set to zero or a small value close to zero for the frequencies where the distribution ratio shows a value around 1. By multiplying the spectrum value by this weighting factor, a spectrum correction value for each frequency is obtained, and the presence or absence of knocking is determined by comparing the spectrum correction value for each frequency with a predetermined level.

FIG. 11 is a flow chart showing the procedure for determining whether knocking has occurred. First, the data stored in the RAM 24 is read during the A / D conversion period (step 3
00), frequency analysis is performed to obtain a spectrum (step 310). In the next step 320, the value of the weighting coefficient obtained in the previous processing is read from the memory, and the spectrum value obtained in step 310 is multiplied to obtain the correction value (step 330). In step 340, the total value of the spectrum correction values is compared with the background level, and when the total value is larger than a predetermined number of times the background level, it is determined that knocking is present. judge. Here, the background level is the total value of the spectrum correction values in the combustion process in which knocking is not detected.

In order to update the previous data with the newly obtained vibration data, if it is determined in step 340 that there is no knocking, the process proceeds to step 350, and the stored distribution data at the time of non-knocking and this time are stored. Calculate the weighted average with the distribution data. For the weighted average, the weighted average of spectrum values for each frequency is obtained by the following formula.

Si (new) = (1−α) Si (old) + Si Si (new): Spectral distribution value of frequency i in the current combustion stroke Si (old): Spectral distribution value of frequency i in the previous combustion stroke Si: Spectral value in the current combustion stroke α: Weighting coefficient (example: α = 1/16) In step 360, the distribution data of the obtained weight average is stored in the memory. Then, the ratio between the new distribution data and the distribution data at knocking is calculated (step 39).
0), find the weighting coefficient to be used next time (step 40
0), this processing is ended. The value of the weighting factor is, for example, a weighting factor = 0 for frequencies having a spectrum value ratio of a predetermined value or less, and a value proportional to the ratio value for frequencies of a predetermined value or more.

When knocking is determined to be present in step 340, the process proceeds to steps 360 and 380, and the distribution data when knocking is present is updated with new data as in steps 350 and 370 described above.

The above processing procedure is repeated for each ignition cycle, the spectral distributions are sequentially compared, and the weighting coefficient is updated. Therefore, regardless of the type of the internal combustion engine, manufacturing variations, and secular change, there is no relation to knocking such as mechanical noise. The vibration component is automatically eliminated, and the accuracy of determining whether knocking has occurred is increased. Therefore, as a result of this determination, the control of the ignition timing becomes good, and it is possible to always suppress the occurrence of knocking.

12 and 13 relate to the fourth embodiment of the present invention. Similar to the second embodiment, in order to drive the internal combustion engine satisfactorily in any operating state, it is preferable to perform the knocking determination process of the third embodiment for each operating region of the internal combustion engine. In the fourth embodiment, as shown in FIG. 13, the operating region is divided into nine regions according to the rotation speed and load of the internal combustion engine, and the process shown in FIG. 11 is executed for each region. A processing procedure therefor is shown in FIG. In this process, first, at step 410, the current operating region is obtained from the rotation speed and the load, and thereafter, knocking determination process is performed using the distribution data and the weighting coefficient stored in the storage device for each operating region. This knocking determination process is similar to the process shown in FIG. 11, and the same step number is assigned to the step performing the same process as the process step in FIG.

As described above, by having the past distribution data have the weighting coefficient for each operation region, the distribution calculation after the sudden change can be immediately performed even when the operating state suddenly changes, and the deterioration of the detection accuracy can be prevented.

[0032]

According to the present invention, it is possible to always determine whether or not knocking is excellent regardless of the type of the internal combustion engine, manufacturing variations, and secular change. Therefore, the ignition timing is advanced to the extent that knocking does not occur. It becomes possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a knocking determination method in an ignition control device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a control system of an internal combustion engine to which an ignition device according to an embodiment of the present invention is applied.

FIG. 3 is a configuration diagram of a control unit shown in FIG.

FIG. 4 is an operation explanatory diagram of a control unit that determines the presence or absence of knocking.

FIG. 5 is a diagram illustrating an operation when an output signal of a vibration sensor is converted into digital data by an A / D converter and is taken into a CPU.

FIG. 6 is a flowchart of a process of performing knocking determination of FIG.

FIG. 7 is an explanatory diagram of a smoothing process shown in FIG.

FIG. 8 is a flowchart showing a processing procedure of a control method in the ignition timing control device according to the second embodiment of the present invention.

FIG. 9 is a divided view of operating regions.

FIG. 10 is an explanatory diagram of knocking determination in the ignition timing control device according to the third embodiment of the present invention.

FIG. 11 is a flowchart showing a procedure for determining knocking presence / absence described in FIG. 10;

FIG. 12 is a flowchart showing a knocking determination processing procedure according to the fourth example of the present invention.

FIG. 13 is a divided view of operating regions.

[Explanation of symbols]

7 ... Internal combustion engine, 9 ... Control unit, 12 ... Crank angle sensor, 13 ... Ignition coil, 14 ... Distributor, 15
... spark plug, 17 ... vibration sensor, 20 ... CPU, 21
... A / D converter, 24 ... RAM.

Claims (13)

[Claims] 1. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on an analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. Means for obtaining a difference or ratio between the first vibration data of the internal combustion engine and the second vibration data of the internal combustion engine in the ignition timing range in which it is determined that knocking has occurred, and a knocking characteristic represented by taking the difference or ratio. An ignition timing control device for an internal combustion engine, comprising means for determining the presence or absence of knocking depending on whether or not is included in vibration data obtained for each ignition of the internal combustion engine. 2. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on the analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. A means for obtaining a difference or a ratio between the first accumulated data of the vibration data of the internal combustion engine and the second accumulated data of the vibration data of the internal combustion engine in the ignition timing range in which it is determined that knocking has occurred, and obtaining the difference or the ratio. Determining means for determining the presence or absence of knocking depending on whether or not the knocking characteristic represented by is included in the vibration data obtained for each ignition of the internal combustion engine, and the vibration data for which the presence or absence of knocking is determined depending on whether the knocking is present An ignition timing control device for an internal combustion engine, comprising: means for accumulating the first accumulated data or the second accumulated data. 3. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on the analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. A means for obtaining the difference or ratio between the magnitude of the vibration component with respect to the crank angle of the internal combustion engine and the magnitude of the vibration component with respect to the crank angle of the internal combustion engine in the ignition timing range determined to cause knocking, and taking this difference or ratio. An ignition timing control device for an internal combustion engine, comprising means for determining the presence or absence of knocking based on whether or not the knocking characteristic represented by (5) is included in the vibration data obtained for each ignition of the internal combustion engine. 4. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on an analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. Cumulative data a of data representing the magnitude of the vibration component with respect to the crank angle of the internal combustion engine, and cumulative data b of data representing the magnitude of the vibration component with respect to the crank angle of the internal combustion engine in the ignition timing range in which it is determined that knocking has occurred. And means for obtaining the difference or ratio between the accumulated data a and the accumulated data b,
Ignition of an internal combustion engine comprising means for determining the presence or absence of knocking based on whether or not a knocking characteristic represented by taking this difference or ratio is included in vibration data obtained for each ignition of the internal combustion engine. Timing control device. 5. The knocking characteristic according to claim 3 or 4, wherein the knocking characteristic is a vibration component of a crank angle at which the difference or ratio shows the largest value, and it is determined that knocking occurs when the vibration component exceeds a predetermined threshold value. An ignition timing control device for an internal combustion engine, comprising: 6. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on the analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. Means for analyzing the vibration data of the internal combustion engine to obtain the frequency spectrum A; means for analyzing the vibration data of the internal combustion engine in the ignition timing range in which knocking is determined to occur to obtain the frequency spectrum B; Means for obtaining the difference or ratio between the distribution of the frequency spectrum B and the distribution of the frequency spectrum B, and whether or not the knocking characteristic represented by taking the difference or ratio is included in the vibration data obtained for each ignition of the internal combustion engine. An ignition timing control device for an internal combustion engine, comprising: means for determining whether or not knocking has occurred. 7. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on the analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. The vibration data of the internal combustion engine is analyzed to obtain the frequency spectrum A, the means for accumulating the cumulative data a of the distribution of the frequency spectrum A, and the vibration data of the internal combustion engine in the ignition timing range determined to cause knocking are analyzed. The frequency spectrum B is obtained by calculating the cumulative data b of the distribution of the frequency spectrum B.
For calculating the knocking characteristic from the difference or ratio between the accumulated data a and the accumulated data b, and whether the knocking characteristic is included in the frequency spectrum of the vibration data obtained for each ignition of the internal combustion engine. An ignition timing control device for an internal combustion engine, comprising: means for determining whether or not knocking has occurred. 8. The knocking characteristic according to claim 6 or 7, wherein the knocking characteristic is a frequency component having a maximum difference or ratio, and knocking is determined to occur when the frequency component exceeds a predetermined threshold value. Ignition timing control device for internal combustion engine. 9. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on an analysis result of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. Means for analyzing the vibration data of the internal combustion engine to obtain the frequency spectrum A; means for analyzing the vibration data of the internal combustion engine in the ignition timing range in which knocking is determined to occur to obtain the frequency spectrum B; Of the frequency spectrum B and the distribution of the frequency spectrum B, means for determining the weighting factor for each frequency component represented by taking the difference or ratio, and obtained for each ignition of the internal combustion engine. Means for determining the presence or absence of knocking based on a spectrum correction value obtained by multiplying each frequency component of vibration data by the weighting coefficient. An ignition timing control device for an internal combustion engine, comprising: 10. An ignition timing control device for an internal combustion engine, which determines the presence or absence of knocking of the internal combustion engine based on a result of analysis of vibration data of the internal combustion engine to control the ignition timing, within an ignition timing range in which it is determined that knocking has not occurred. The vibration data of the internal combustion engine is analyzed to obtain the frequency spectrum A, the means for accumulating the cumulative data a of the distribution of the frequency spectrum A, and the vibration data of the internal combustion engine in the ignition timing range determined to cause knocking are analyzed. The frequency spectrum B is obtained by calculating the cumulative data b of the distribution of the frequency spectrum B.
Means for determining the weighting coefficient for each frequency component from the difference or ratio between the cumulative data a and the cumulative data b, and the weighting coefficient for each frequency component of the vibration data obtained for each ignition of the internal combustion engine. An ignition timing control device for an internal combustion engine, comprising means for determining the presence or absence of knocking based on a correction value of a spectrum obtained by multiplication. 11. The weight coefficient determining means according to claim 10, wherein the weight coefficient of each frequency component is determined from the difference or ratio between the average value of the accumulated data a and the average value of the accumulated data b. Ignition timing control device for internal combustion engine. 12. The ignition timing control device for an internal combustion engine according to claim 9, wherein a frequency component whose difference or ratio is equal to or less than a predetermined value is not used for determining whether knocking has occurred. 13. The knocking presence / absence determination according to any one of claims 1 to 12, based on vibration data of the internal combustion engine accumulated for each operating region divided by a load of the internal combustion engine speed. A characteristic ignition timing control device for an internal combustion engine.