JP2017066887A - Internal combustion engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine control device that can determine if knock has occurred or not in a period where injector noise and knock coincide with each other.SOLUTION: The internal combustion engine control device determines if knock has occurred or not in a period where vibration of valve closing and opening of a fuel injection valve 5 exists, from the vibration of valve closing and opening of the fuel injection valve 5 that is included in a knock sensor signal output from a knock sensor 8 for detecting vibration of the internal combustion engine 1.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an internal combustion engine control device, and more particularly to an internal combustion engine control device that performs knock determination of an internal combustion engine.

  In an internal combustion engine, knock determination for determining the presence or absence of knock is usually performed, and knock control for adjusting the ignition timing and the like according to the result is performed.

  This knock determination is performed using a knock sensor which is a vibration detection sensor provided in a cylinder block or the like, and a predetermined period during which knocking after each cylinder is ignited is set as the knock determination period. The presence or absence of knock is determined based on the output signal (knock sensor signal) of the knock sensor during the determination period.

  As a characteristic of the internal combustion engine, if the ignition timing is advanced, the output torque of the internal combustion engine is improved, but knocking is likely to occur. Conversely, if the ignition timing is retarded, the output torque of the internal combustion engine is reduced, but knocking is less likely to occur.

  Therefore, conventionally, when the knock is detected by the above-described knock determination, the ignition timing is corrected to the retard side to suppress the knock, and when no knock is detected, the ignition timing is set to the advance side. A knock control device that returns to the minimum and minimizes the torque drop is applied.

  The knock control device enables the internal combustion engine to be operated at the ignition timing of the knock limit that outputs the maximum torque while suppressing the knock.

  In the knock control device, there is known a method for determining the presence or absence of knock from the peak value of vibration intensity in a set knock determination period, the magnitude of a specific frequency component obtained by frequency analysis of vibration, and the like. .

  However, depending on the operating state of the internal combustion engine, vibration (noise vibration) not caused by knock may be superimposed on the output signal of the knock sensor in the knock determination period. In this case, there is a possibility that knock detection or detection omission may occur, and it becomes difficult to accurately detect actual knock vibration.

  As an example, a fuel injection valve (also referred to as an injector) that injects fuel into a combustion chamber of an internal combustion engine generates noise vibrations (injector noise) such as a landing sound when seated, and the injector noise. Is superimposed on the output signal of the knock sensor in the knock determination period, and the presence or absence of knock may be erroneously determined.

  As a result, although the knock does not occur, the ignition timing is unnecessarily corrected to the retard side, which may lead to a decrease in torque and a deterioration in fuel consumption.

  As described above, if the fuel injection timing and the knock determination period are set without considering the injector noise, the injector noise may be superimposed on the knock determination period, which may cause an erroneous determination of the presence or absence of the knock. The accuracy of knock determination decreases due to the influence.

  With respect to such a problem, in the prior art described in Patent Document 1, the knock determination period is shorter than the default setting in the engine operation condition in which the default knock determination period overlaps the fuel injection period from the injector. Thus, the fuel injection timing and the knock determination period are set in association with each other so as to eliminate the overlap between the fuel injection period and the knock determination period.

  By this conventional technology, it is avoided that the injector noise is superimposed on the output signal of the knock sensor during the knock determination period, and the deterioration of the accuracy of the knock determination due to the noise is suppressed.

JP 2004-251218 A

  However, in the prior art described in Patent Document 1, the knock determination period is set so that the injector noise is not superimposed on the output signal of the knock sensor in the knock determination period. However, the period in which the injector noise is superimposed is determined from the knock determination period. If excluded, there is a problem that it is not determined that there is a knock when the injector noise and the knock overlap.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a control device for an internal combustion engine that can determine the presence or absence of knocking in a period in which injector noise and knocking overlap. There is.

  In order to solve the above-described problems, a control device for an internal combustion engine according to the present invention controls the opening and closing of a fuel injection valve that injects fuel into a combustion chamber of the internal combustion engine based on the operating state of the internal combustion engine. A control device for an internal combustion engine, comprising: a control unit; and a knock determination unit that determines presence or absence of knock based on a knock sensor signal output from a knock sensor that detects vibration of the internal combustion engine, wherein the knock sensor signal The presence or absence of knocking during a period in which there is vibration of the fuel injection valve open and close is determined from the vibration of the valve opening and closing of the fuel injection valve.

  According to the present invention, it is possible to determine the presence or absence of knocking during a period in which injector noise and knocking overlap.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which showed one Embodiment of the control apparatus (ECU) of the internal combustion engine which concerns on this invention, and the spark ignition internal combustion engine to which it was applied. The block diagram which showed the internal structure of ECU shown in FIG. The control block diagram which showed the main structures of ECU shown in FIG. The figure shown about the combustion stroke of each cylinder in a 4-cylinder internal combustion engine, the knock determination period in a # 1 cylinder, and an example of injector noise. The figure which showed an example of the knock sensor signal of the injector noise waveform acquisition period in the 4th previous stroke, and the knock sensor signal of the knock determination period in the current stroke (when there is no knock in the injector noise waveform acquisition period). The figure which showed an example of the normalization cross-correlation function of the knock sensor signal of the valve opening noise period in the process 4 steps before, and the present process. Example of time chart of knock sensor signal, normalized cross-correlation function maximum value between valve-opening noise periods, normalized cross-correlation function maximum value between valve-closing noise periods, and knock determination result during injector noise waveform acquisition period Figure. The flowchart which showed the flowchart of the knock determination process by ECU shown in FIG.

  Hereinafter, an internal combustion engine control apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of a control device for an internal combustion engine (hereinafter referred to as “engine control unit (ECU)”) according to the present invention and the basics of a spark ignition internal combustion engine (hereinafter referred to as “engine”) to which the control device is applied. It is the block diagram which showed the structure. Hereinafter, in this description, the explanation will be made on the in-cylinder injection spark ignition internal combustion engine. However, the present invention relates to a port injection spark ignition internal combustion engine and a dual injection spark having both in-cylinder injection and port injection. Of course, the present invention can also be applied to an ignition internal combustion engine.

  As shown in the figure, the engine 1 is basically provided with a piston 2, an intake valve 3, and an exhaust valve 4, and the intake air passes through an air flow meter (AFM) 18 and enters a throttle valve 17, and branches. Is supplied to the combustion chamber 19 of the engine 1 through the intake pipe 10 and the intake valve 3. Fuel is injected and supplied from a fuel injection valve (injector) 5 to a combustion chamber 19 of the engine 1 and ignited by an ignition coil 7 and a spark plug 6. The exhaust gas after combustion is discharged to the exhaust pipe 11 through the exhaust valve 4. The exhaust pipe 11 is provided with an air-fuel ratio sensor 13 for detecting an air-fuel ratio in the exhaust gas, and a three-way catalyst 12 for purifying the exhaust gas. The engine control unit (ECU) 9 includes a signal from the crank angle sensor 15 disposed on the signal plate 16 of the engine 1 to measure the rotational speed of the engine 1, a signal related to the air amount of the AFM 18, A signal relating to the fuel ratio, a signal relating to the accelerator opening of the accelerator opening sensor 20, and the like are input. The ECU 9 calculates the required torque to the engine 1 from the signal of the accelerator opening sensor 20, determines the idling state, etc., calculates the intake air amount necessary for the engine 1, and sets the opening signal corresponding to the intake air amount to the throttle valve 17. Output to. Further, the ECU 9 outputs a fuel injection signal (a control signal related to the opening / closing valve timing of the fuel injection valve 5) to the fuel injection valve 5, and outputs an ignition signal (a control signal related to the ignition timing of the ignition plug 6) to the ignition plug 6. To do.

  Further, knock sensor 8 attached to engine 1 (the cylinder thereof) detects a knock (vibration) generated during abnormal combustion of engine 1, and based on the knock sensor signal output from knock sensor 8, ECU 9 The ignition signal is feedback-controlled.

  FIG. 2 is a block diagram showing an internal configuration of the ECU 9 shown in FIG.

  The ECU 9 includes a microcomputer including an input circuit 101, an A / D conversion unit 102, a central processing unit (CPU) 103, a ROM 104, a RAM 105, an output circuit 106, and the like.

  When the input signal 100 is an analog signal (for example, when it is a signal from the AFM 18, the accelerator opening sensor 20, etc.), the input circuit 101 removes a noise component from the signal and converts the signal into an A / D signal. This is for output to the conversion unit 102.

  The A / D converter 102 is for converting an analog signal input from the input circuit 101 into a digital signal.

  The CPU 103 captures the A / D conversion result of the A / D conversion unit 102 and executes each control, diagnosis, and the like by executing a fuel injection control program and other control programs stored in a medium such as the ROM 104. It has a function. The calculation result of the CPU 103 and the A / D conversion result are temporarily stored in the RAM 105, and the calculation result is output as the control signal 107 via the output circuit 106, and the fuel injection valve 5, the ignition coil 7 or the like (open / close valve timing control of the fuel injection valve 5 or ignition timing control of the spark plug 6).

  Next, the knock determination of the engine 1 by the ECU 9 shown in FIG. 1 will be specifically described with reference to FIGS.

  FIG. 3 is a control block diagram showing the main configuration of ECU 9 shown in FIG.

  As shown in the figure, the ECU 9 mainly determines whether or not the engine 1 is knocked, an ignition control unit 211 that controls the ignition timing of the spark plug 6, a fuel injection control unit 212 that controls the opening and closing of the fuel injection valve 5. And a knock determination unit 210.

  Knock determination unit 210 calculates knock determination period based on the engine speed obtained from crank angle sensor 15 and the ignition timing obtained from ignition control unit 211 in knock determination period calculation unit 200, and obtains a knock determination period waveform. In unit 201, a knock sensor signal (knock determination period waveform) for the knock determination period is acquired. Then, in knock determination period knock determination unit 202, the presence / absence of knock in the knock determination period is determined from the knock sensor signal in the knock determination period, the background level calculated including the knock sensor signal in the past knock determination period, or the like. To do.

  In addition, the knock determination unit 210 performs an injector noise waveform acquisition period (fuel injection valve 5) based on the on-off valve timing (that is, fuel injection timing) obtained from the fuel injection control unit 212 in the injector noise waveform acquisition period calculation unit 203. The injector noise waveform acquisition unit 204 acquires a knock sensor signal (injector noise waveform) during the injector noise waveform acquisition period.

  The period overlap determination unit 205 calculates an overlap period between the knock determination period calculated by the knock determination period calculation unit 200 and the injector noise waveform acquisition period calculated by the injector noise waveform acquisition period calculation unit 203, and the overlap period. It is determined whether or not is longer than a predetermined value.

  Then, knock determination period knock determination unit 202 determines that there is a knock in the knock determination period, and period overlap determination unit 205 determines that the overlap period between the knock determination period and the injector noise waveform acquisition period is longer than a predetermined value. When it is determined, the injector noise waveform acquisition period knock determination unit 206 determines whether or not there is a knock in the injector noise waveform acquisition period. In addition, when the knock determination period knock determination unit 202 determines that there is no knock in the knock determination period, or in the period overlap determination unit 205, the overlap period between the knock determination period and the injector noise waveform acquisition period is equal to or less than a predetermined value. In the case where it is determined, the injector noise waveform acquisition period knock determination unit 206 does not determine whether or not there is a knock in the injector noise waveform acquisition period (it is not necessary to determine).

  Next, the method for determining the presence or absence of knock in the injector noise waveform acquisition period by the injector noise waveform acquisition period knock determination unit 206 will be described in more detail.

  FIG. 4 is a diagram showing the combustion stroke of each cylinder in the four-cylinder internal combustion engine, the knock determination period and the injector noise in the # 1 cylinder.

  For ignition in the compression stroke of # 1 cylinder, the knock determination period is set to a stroke (generally in the range of ATDC 10 ° to 60 °) in which # 1 cylinder is in the expansion stroke.

  In an internal combustion engine whose ignition cylinder order is # 1, # 3, # 4, and # 2, when fuel injection is performed from the combustion injection valve 5 in the intake stroke, the knock sensor signal in the knock determination period of the # 1 cylinder includes # 4-cylinder injector noise may be superimposed.

  In order to determine whether or not the knock is superimposed on the injector noise in the current stroke, the knock sensor signal during the injector noise waveform acquisition period in the current stroke and the previous four strokes in which the # 1 cylinder was in the expansion stroke The knock sensor signal during the injector noise waveform acquisition period at is divided into two periods, the valve opening noise period and the valve closing noise period, respectively, and the normalized cross-correlation function between the valve opening noise period and the valve closing noise period is calculated. To do.

It is known that the cross-correlation function φ _xy (τ) of the discrete-time signals x (k) and y (k) is defined by the following equation (1). Here, N is the number of discrete-time signal data, and τ is lag.
(Equation 1)

Further, it is known that the normalized cross correlation function R _xy (τ) is defined by the following equation (2).
(Equation 2)

When the similarity between the discrete-time signals x (k) and y (k) is high, the maximum value of the normalized cross-correlation function R _xy (τ) increases.

  FIG. 5 shows the knock sensor signal (the signal acquired by the injector noise waveform acquisition unit 204) in the injector noise waveform acquisition period in the previous four strokes, and the knock determination period (including the injector noise waveform acquisition period) in the current stroke. It is a figure showing a knock sensor signal (when there is no knock in the injector noise waveform acquisition period and when there is a knock) (signal acquired by knock determination period waveform acquisition unit 201).

  As shown in the figure, the knock sensor signal of the injector noise waveform acquisition period is divided into a valve opening noise period and a valve closing noise period in the current process and the four previous processes, respectively. A normalized cross-correlation function is calculated between periods. The reason why the knock sensor signal is divided into the valve opening noise period and the valve closing noise period is that the interval between the valve opening and the valve closing changes according to the fuel injection amount in each stroke.

  Compared to the case where there is a knock in the injector noise waveform acquisition period (bottom diagram), the case where there is no knock in the injector noise waveform acquisition period (interruption diagram), the injector noise waveform acquisition period in the previous four strokes Since the degree of similarity with the knock sensor signal is high, the maximum value of the normalized cross-correlation function described above increases.

  When the maximum value of the normalized cross-correlation function of the valve opening noise period and the valve closing noise period is equal to or greater than a predetermined threshold value, the knock sensor signal of the injector noise waveform acquisition period in the current stroke and the previous four strokes It is possible to determine that there is no knock in the injector noise, that is, there is no knock in the injector noise waveform acquisition period in the current stroke. On the other hand, when one or both of the maximum values of the normalized cross-correlation functions in the valve opening noise period and the valve closing noise period are less than a predetermined threshold, the injector noise waveform is generated in the current stroke and the previous four strokes. It can be determined that the knock sensor signal similarity in the acquisition period is low and the knock is superimposed on the injector noise, that is, there is a knock in the injector noise waveform acquisition period in the current stroke.

  Here, the threshold of the maximum value of the normalized cross-correlation function for determining that there is no knock in the injector noise waveform acquisition period in the current process is the maximum value of the normalized cross-correlation function calculated in the same way in the past May be calculated for each stroke, or may be a value set in advance in the ROM.

  Further, when it is determined that there is a knock in the injector noise waveform acquisition period in the four strokes before the comparison target, the acquisition of the injector noise waveform with no knock superimposed is made the comparison target eight strokes before. What is necessary is just to compare the knock sensor signal of a period with the knock sensor signal of the injector noise waveform acquisition period in the present process.

  FIG. 6 is a diagram showing the normalized cross-correlation function of the knock sensor signal during the valve opening noise period in the previous stroke and the current stroke.

  As described above, when there is no knock in the valve opening noise period of the injector noise waveform acquisition period in the current stroke, the maximum value of the normalized cross-correlation function is larger than when there is a knock.

  By appropriately setting a threshold for determining that there is no knock in the injector noise waveform acquisition period, the maximum value of the normalized cross-correlation function is equal to or greater than the threshold when there is no knock in the injector noise waveform acquisition period. On the other hand, when there is a knock in the injector noise waveform acquisition period, the maximum value of the normalized cross-correlation function is less than the threshold value.

  In this way, by determining whether or not the maximum value of the normalized cross-correlation function calculated by the injector noise waveform acquisition period knock determination unit 206 is greater than or equal to the threshold value, the presence or absence of knock in the valve opening noise period is determined. Further, regarding the valve closing noise period, the presence or absence of knocking is determined in the same manner as the valve opening noise period.

  When it is determined that there is no knock in both the valve opening noise period and the valve closing noise period, it can be determined that there is no knock in the injector noise waveform acquisition period in the current stroke.

  Here, as a threshold for determining that there is no knock in the injector noise waveform acquisition period, it is natural that separate values may be set for the valve opening noise period and the valve closing noise period.

  FIG. 7 is a time chart of knock sensor signal, normalized cross-correlation function maximum value between valve opening noise periods, normalized cross-correlation function maximum value between valve closing noise periods, and knock determination result of injector noise waveform acquisition period. FIG.

  In the case of the condition shown in FIG. 4, the injector noise of the # 4 cylinder may be superimposed on the knock determination period set in the expansion stroke of the # 1 cylinder. Therefore, in FIG. 7, only the combustion stroke of the # 1 cylinder and the combustion stroke of the # 4 cylinder are illustrated, and the knock sensor signal at that time, the normalized cross-correlation function maximum value between the valve opening noise periods, and the valve closing noise periods are shown. The normalized cross-correlation function maximum value and the knock determination result during the injector noise waveform acquisition period are illustrated. Hereinafter, the relationship between them will be described.

  The determination of the presence or absence of knock in the injector noise waveform acquisition period by the injector noise waveform acquisition period knock determination unit 206 is performed after both the knock determination period and the injector noise waveform acquisition period in the process are completed.

  In the example shown in FIG. 7, at the time of switching between the expansion stroke and the exhaust stroke of the # 1 cylinder, it is determined whether or not there is a knock in the injector noise waveform acquisition period.

  When the knock sensor signal when the knock is superimposed on the injector noise is the knock sensor signal of the injector noise waveform acquisition period shown in the lower part of FIG. 5 (when there is a knock in the injector noise waveform acquisition period), the knock is detected in the injector noise. Compared with the case where no is superimposed, the normalized cross-correlation function maximum value between the valve opening noise periods is greatly reduced.

  Therefore, the maximum normalized cross-correlation function between the valve opening noise periods, which has been equal to or higher than the threshold for determining that there is no knock in the injector noise waveform acquisition period, is a value less than the threshold. As a result, the knock determination result in the injector noise waveform acquisition period is “with knock”.

  In the above example, the knock is superimposed on the valve opening noise period of the injector noise waveform acquisition period. However, when the knock is superimposed on the valve closing noise period, the normalized cross-correlation function between the valve closing noise periods is used. The maximum value is less than a threshold value for determining that there is no knock in the injector noise waveform acquisition period, and the knock determination result in the injector noise waveform acquisition period is “with knock”.

  FIG. 8 is a flowchart showing a flowchart of knock determination processing by ECU 9 shown in FIG.

  First, it is determined whether or not it is determined that there is a knock in the knock determination period in the knock determination period (S801). If it is determined that there is no knock, false detection of knock due to superposition of injector noise on the knock determination period Therefore, it is not necessary to determine whether or not there is a knock in the injector noise waveform acquisition period, and thus the knock determination process in the injector noise waveform acquisition period ends.

  On the other hand, when it is determined that there is a knock in the knock determination in the knock determination period, it is determined whether or not the overlap period of the knock determination period and the injector noise waveform acquisition period is longer than a predetermined value (S802). When the overlap period is equal to or less than a predetermined value, the injector noise waveform is not necessary to determine the presence or absence of knock in the injector noise waveform acquisition period because the injector noise is not superimposed or hardly superimposed in the knock determination period. The knock determination process in the acquisition period ends.

  On the other hand, when the overlap period of the knock determination period and the injector noise waveform acquisition period is longer than the predetermined value, the normalization of the knock sensor signal in the valve opening noise period in the injector noise waveform acquisition period in the four previous strokes and the current stroke is performed. It is determined whether the maximum value of the correlation function is equal to or greater than a predetermined threshold (S803). Similarly, it is determined whether or not the maximum value of the normalized cross-correlation function of the knock sensor signal during the valve closing noise period in the injector noise waveform acquisition period is equal to or greater than a predetermined threshold (S804).

  When the maximum value of the normalized cross-correlation function is not less than a predetermined threshold value in both the valve opening noise period and the valve closing noise period, it is determined that there is no knock in the injector noise waveform acquisition period (S805), and the valve opening noise period, If it is less than the predetermined threshold in any of the valve closing noise periods, it is determined that there is a knock in the injector noise waveform acquisition period (S806).

  By the method as described above, it is possible to determine the presence or absence of knocking in the injector noise waveform acquisition period (that is, the period during which the injector noise and knocking may overlap).

  In this embodiment, using the normalized cross-correlation function of the knock sensor signal in the injector noise waveform acquisition period between the previous four strokes and the current stroke, the knock in the injector noise waveform acquisition period in the current stroke is used. Although the presence / absence is determined, the determination method is not limited to this, and the normalized cross-correlation of the knock sensor signal during the injector noise waveform acquisition period between the 4th previous stroke and the 8th previous stroke A function may be used, and similarly, determination may be made using a knock sensor signal in the injector noise waveform acquisition period of the previous stroke.

  Moreover, you may determine using not only the cylinder which has set the knock determination period in the present process but the normalization cross-correlation function calculated similarly in the past in another cylinder.

  Needless to say, the determination method may be set for each cylinder or the determination method may be changed for each cylinder, instead of determining the same for all cylinders.

  In addition, this invention is not limited to above-described embodiment, Various deformation | transformation forms are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

1. Engine (internal combustion engine)
2 ... piston 3 ... intake valve 4 ... exhaust valve 5 ... fuel injection valve 6 ... spark plug 7 ... ignition coil 8 ... knock sensor 9 ... engine control unit ( ECU) (control device for internal combustion engine)
DESCRIPTION OF SYMBOLS 10 ... Intake pipe 11 ... Exhaust pipe 12 ... Three-way catalyst 13 ... Air-fuel ratio sensor 14 ... Collector 15 ... Crank angle sensor 16 ... Signal plate 17 ... Throttle valve 18 ... Air flow meter (AFM)
DESCRIPTION OF SYMBOLS 19 ... Combustion chamber 20 ... Accelerator opening sensor 100 ... Input signal 101 ... Input circuit 102 ... A / D conversion part 103 ... Central processing part (CPU)
104 ... ROM
105 ... RAM
106 ... Output circuit 107 ... Control signal 200 ... Knock determination period calculation unit 201 ... Knock determination period waveform acquisition unit 202 ... Knock determination period knock determination unit 203 ... Injector noise waveform acquisition period Calculation unit 204 ... injector noise waveform acquisition unit 205 ... period overlap determination unit 206 ... injector noise waveform acquisition period knock determination unit 210 ... knock determination unit 211 ... ignition control unit 212 ... fuel Injection control unit

Claims (5)

A fuel injection control unit that controls opening and closing of a fuel injection valve that injects fuel into a combustion chamber of the internal combustion engine based on an operating state of the internal combustion engine, and a knock sensor that is output from a knock sensor that detects vibration of the internal combustion engine A control device for an internal combustion engine comprising a knock determination unit for determining presence or absence of knock based on a signal,
An internal combustion engine that determines whether or not there is a knock in a period in which vibrations of opening and closing of the fuel injection valve exist from vibrations of opening and closing of the fuel injection valve included in the knock sensor signal. Engine control device. The control apparatus for an internal combustion engine according to claim 1,
From the normalized cross-correlation function for the opening and closing vibrations of the fuel injection valve in the past stroke and the opening and closing vibrations of the fuel injection valve in the current stroke, the opening of the fuel injection valve And a control device for an internal combustion engine, wherein the presence or absence of knocking in a period in which vibration of the valve closing exists is determined. The control apparatus for an internal combustion engine according to claim 1,
The maximum value of the normalized cross-correlation function for the opening and closing vibrations of the fuel injection valve in the past stroke and the opening and closing vibrations of the fuel injection valve in the current stroke is not less than a predetermined threshold value. In some cases, the control apparatus for an internal combustion engine determines that there is no knock in a period in which vibrations of the fuel injection valve open and close exist. The control apparatus for an internal combustion engine according to claim 1,
A normalized cross-correlation function for the vibration of the fuel injector opening in the past stroke and the vibration of the fuel injector opening in the current stroke, and the closing of the fuel injector in the past stroke Determining from the normalized cross-correlation function related to the vibration and the vibration of the valve closing of the fuel injection valve in the current stroke whether or not there is a knock in the period in which the fuel injection valve is open and the valve closing vibration exists. A control device for an internal combustion engine characterized by the above. The control apparatus for an internal combustion engine according to claim 1,
When the maximum value of the normalized cross-correlation function relating to the vibration of the fuel injection valve opening in the past stroke and the vibration of the fuel injection valve opening in the current stroke is equal to or greater than a predetermined threshold; When the maximum value of the normalized cross-correlation function relating to the vibration of the closing valve of the fuel injection valve in the stroke of the current and the vibration of the closing valve of the fuel injection valve in the current stroke is equal to or greater than a predetermined threshold value, A control apparatus for an internal combustion engine, characterized in that it is determined that there is no knock during a period in which vibrations of the valve opening and closing exist.

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