JP2015031181A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine including a bypass passage, capable of improving the accuracy of calculating an intake valve passing flow amount.SOLUTION: The control device is provided for the internal combustion engine which includes a throttle, an air flow meter, the bypass passage, and a bypass flow control valve. It predicts an intake valve passing air flow amount as the flow amount of air to pass through an intake valve, calculates an air flow meter flow amount as the flow amount of air passing through the air flow meter from the output of the air flow meter, calculates a bypass flow amount as the flow amount of air flowing in the bypass passage on the basis of the opening of the bypass flow control valve, calculates an intake passage flow amount as the flow amount of air flowing in an intake passage from the air flow meter flow amount and the bypass flow amount, and calculates the intake valve passing air flow amount on the basis of the intake passage flow amount and the bypass flow amount, using the physical model of an intake system including the throttle.

Description

  The present invention relates to a control device for an internal combustion engine.

  Conventionally, in a supercharged engine, a physical model for calculating a flow rate of air passing through an intake valve (hereinafter referred to as an intake valve passage flow rate) is known. This physical model is a physical model of the behavior of air in the intake passage. Hereinafter, a specific calculation method of the intake valve passage flow rate using this physical model will be described.

  First, the air flow meter flow rate is calculated based on the output of the air flow meter. Next, the calculated air flow meter flow rate is arithmetically processed in the order of the intercooler model and the throttle model in the physical model to calculate the throttle flow rate. Further, the calculated throttle flow rate is processed in the order of the intake pipe model and the intake valve model. Thereby, the intake valve passage flow rate is finally calculated. As described above, in the above physical model, calculation processing is performed by each model in the order from the upstream to the downstream of the intake passage. For this reason, the intake valve passage flow rate can be calculated from the output of the air flow meter.

JP 2008-144605 A Japanese Patent No. 3760757 JP-A-8-114143 JP-A-8-144809 JP-A-11-014507

  By the way, Patent Document 1 discloses an engine in which a bypass passage is provided in the intake passage so as to bypass the throttle valve. Since the above physical model does not consider air that bypasses the throttle, there is a concern that the intake valve passage flow rate cannot be accurately calculated even if the above physical model is used as it is for such an engine.

  The present invention has been made to solve the above-described problems, and provides an internal combustion engine control apparatus capable of improving the calculation accuracy of the intake valve passage flow rate in an engine having a bypass passage. Objective.

In order to achieve the above object, a first invention is a control device for an internal combustion engine,
A throttle (40) disposed in the intake passage, an air flow meter (50) attached upstream of the throttle (40), a downstream of the air flow meter (50) bypassing the throttle (40), and an intake valve (16) provided for an internal combustion engine comprising a bypass passage (46) connecting the upstream of (16) and a bypass flow rate control valve (48) disposed in the bypass passage (46), the intake valve (16) A control device that predicts an intake valve passage air flow rate (mc) that is a flow rate of air passing through the engine and controls the internal combustion engine based on the intake valve passage air flow rate (mc).
Air flow meter flow rate calculation means (102) for calculating an air flow meter flow rate (mafm) which is a flow rate of air passing through the air flow meter from an output of the air flow meter (50);
Bypass flow rate calculation means (104) for calculating a bypass flow rate (mafmisc), which is a flow rate of air flowing through the bypass passage, based on an opening of the bypass flow rate control valve;
An intake passage flow rate calculation means (104) for calculating an intake passage flow rate (mafmcmp) which is a flow rate of air flowing into the intake passage from the air flow meter flow rate (mafm) and the bypass flow rate (mafmmisc);
The intake valve passing air flow rate (mc) is calculated based on the intake passage flow rate (mafmcmp) and the bypass flow rate (mafmisc) using a physical model (M1, M2, M3, M4) of the intake system including the throttle. An intake valve passage air flow rate calculating means (106);
It is characterized by providing.

The second invention is the first invention, wherein
The physical model (M1, M2, M3, M4) used by the intake valve passage air flow rate calculating means is a first modeled intake system from a branch point of the bypass passage to the throttle of the intake passage. A physical model (M1, M2) and a second physical model (M3, M4) that models the intake system from the junction of the bypass passage of the intake passage to the intake valve,
The intake valve passage air flow rate calculation means includes:
Means for calculating a throttle flow rate (mt) which is a flow rate of air passing through the throttle from the intake passage flow rate using the first physical model (M1, M2);
Means for calculating the intake valve passing air flow rate (mc) from the total flow rate of the throttle flow rate (mt) and the bypass flow rate (mafmisc) using the second physical model (M3, M4);
It is characterized by including.

The third invention is the first or second invention, wherein
The bypass flow rate calculation means includes
Bypass flow control valve passing flow (misc), which is a flow rate of air passing through the bypass flow control valve, using a bypass flow control valve model (M5) that models the relationship between the opening and flow rate of the bypass flow control valve. A means of calculating
Using an air flow meter model (M6) that models the response characteristics of the air flow meter, the flow rate passing through the bypass flow control valve (misc) is converted into the measured value of the air flow meter, and the converted flow rate is converted into the bypass flow rate ( mafmisc) and output means,
It is characterized by including.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the internal combustion engine includes a compressor in the intake passage, and the bypass passage is branched from the intake passage upstream of the compressor. It is characterized by.

  According to the first invention, the estimation accuracy of the intake valve passage flow rate can be improved. As a result, the controllability of the air-fuel ratio is improved and the emission can be maintained satisfactorily.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram for demonstrating the structure of the system of Embodiment 1 of this invention. In this embodiment, it is a functional block diagram which shows the air quantity estimation model which modeled the behavior of the air in an engine. It is the figure which represented the AFM flow volume division | segmentation part in detail. It is a figure showing the change of the various flow rates calculated with the air quantity estimation model at the time of engine deceleration. It is a figure showing the time-sequential change of the various flow rates calculated by the air quantity estimation model in this embodiment. In a comparative example, it is a functional block diagram which shows the air quantity estimation model which modeled the behavior of the air of the engine. It is a figure showing the change of the time series of the various flow rates computed by the air quantity estimation model in a comparative example.

Embodiment 1 FIG.
[System Configuration of Embodiment 1]
FIG. 1 is a schematic configuration diagram for explaining the configuration of the system according to the first embodiment of the present invention. The system shown in FIG. 1 includes an engine 10. The engine 10 is a spark ignition type four-cycle engine, and is a supercharged engine with an EGR device. Normally, the engine 10 is composed of a plurality of cylinders, but only one cylinder is depicted in FIG. In the present invention, the number of cylinders and the cylinder arrangement are not limited thereto.

  In this embodiment, a turbocharger that compresses intake air using exhaust gas is employed as the supercharger 23. The supercharger 23 has a structure in which a compressor 24 provided in the intake passage 11 and a turbine 22 provided in the exhaust passage 13 are connected via a shaft.

  An intake passage 11 is connected to the combustion chamber 14 of the engine 10. An intake valve 16 is provided at a connection portion between the combustion chamber 14 and the intake passage 11. The intake passage 11 includes an air cleaner 26 at the inlet thereof. A compressor 24 is provided downstream of the air cleaner 26. An intercooler 38 is provided downstream of the compressor 24. A throttle valve 40 is provided downstream of the intercooler 38 in order to adjust the supply amount of intake air in the intake passage 11.

  Here, the intake air flowing through the intake passage 11 will be described. The intake air drawn from the air cleaner 26 is compressed by the compressor 24 and then cooled by the intercooler 38. The intake air cooled by the intercooler 38 passes through the throttle valve 40 and then flows into the intake pipe 42 that is a part of the intake passage 11. The intake air flowing into the intake pipe 42 is taken into the combustion chamber 14 from the intake pipe 42 when the intake valve 16 is opened. The intake pipe 42 in this specification includes an intake manifold and a surge tank.

  An exhaust passage 13 is connected to the combustion chamber 14. An exhaust valve 18 is provided at the connection between the combustion chamber 14 and the exhaust passage 13. When the exhaust valve 18 is opened, the gas generated in the combustion chamber 14 is discharged to the exhaust passage 13. Then, the turbine 22 is rotated by the exhaust. When the turbine 22 rotates, the compressor 24 rotates through the shaft, and supercharging is performed.

  The EGR device 31 in the present embodiment includes an EGR passage 29, an EGR cooler 30, and an EGR valve 32. The EGR passage 29 is provided with the exhaust passage 13 downstream of the turbine 22 as an inlet and the intake passage 11 upstream of the compressor 24 as an outlet. An EGR cooler 30 for cooling the exhaust gas is provided in the EGR passage 29. Further, the EGR passage 29 is provided with an EGR valve 32 for adjusting the amount of gas supplied when the cooled exhaust gas is supplied to the intake passage 11 as EGR gas. The EGR gas is compressed by the compressor 24 together with the intake air from the air cleaner 26 because the outlet of the EGR passage 29 is upstream of the compressor 24.

  The engine 10 is provided with a bypass passage 46. The bypass passage 46 branches from the intake passage 11 upstream of the compressor 24. Specifically, the bypass passage 46 has a structure in which the intake passage 11 between the air cleaner 26 and the compressor 24 is an inlet and the intake passage 11 between the intake pipe 42 and the intake valve 16 is an outlet. Further, the inlet of the bypass passage 46 is provided upstream of the outlet of the EGR passage 29. For this reason, only fresh air drawn from the air cleaner 26 passes through the bypass passage 46. In the bypass passage 46, a bypass flow rate control valve 48 for adjusting the amount of fresh air supplied is provided.

  Various sensors for grasping the operating state of the engine 10 are attached to the intake passage 11. An air flow meter (hereinafter also referred to as AFM) 50 is attached to the downstream side of the air cleaner 26 in order to grasp the flow rate of fresh air drawn into the intake passage 11. A boost pressure sensor 36 is attached between the compressor 24 and the intercooler 38. In the vicinity of the throttle valve 40, a throttle position sensor (not shown) is attached to grasp the opening of the throttle valve 40. An intake pipe temperature sensor 44 is attached in the intake pipe 42.

  The system configuration of the first embodiment includes an ECU 100 (Engine Control Unit) that controls the operating state of the engine 10. Various sensors such as an air flow meter 50, a supercharging pressure sensor 36, an intake pipe temperature sensor 44, a crank angle sensor (not shown), and a throttle position sensor (not shown) are connected to the input side of the ECU 100. The ECU 100 detects the operating state of the engine 10 based on signals output from the various sensors. Specifically, the ECU 100 detects the intake air amount from signals output from the air flow meter 50 and the crank angle sensor. ECU 100 detects the engine speed from the signal output from the crank angle sensor.

  On the other hand, actuators such as an intake valve 16, an exhaust valve 18, an EGR valve 32, a throttle valve 40, and a bypass flow rate control valve 48 are connected to the output side of the ECU 100. The ECU 100 outputs signals for operating various actuators according to the operating state. For example, the ECU 100 adjusts the opening degree of the EGR valve 32 in order to supply the target EGR amount to the intake passage 11 upstream of the compressor 24. In addition, the ECU 100 adjusts the throttle flow rate by operating the opening of the throttle valve 40. In addition, when supplying fresh air from the bypass passage 46 to the combustion chamber 14, the ECU 100 operates the opening of the bypass flow control valve 48 to adjust the bypass flow rate.

  The behavior of air in the engine 10 of this embodiment will be described. According to the configuration of the system of FIG. 1, the intake air supplied to the combustion chamber 14 after passing through the throttle valve 40 contains EGR gas. On the other hand, the auxiliary air supplied from the bypass passage 46 to the combustion chamber 14 does not contain EGR gas, that is, only fresh air can be supplied from the bypass passage 46. The intake air from the intake passage 11 and the auxiliary air from the bypass passage 46 are mixed in the intake passage 11 between the intake pipe 42 and the intake valve 16. The air thus mixed is finally supplied into the combustion chamber 14. An example of supplying fresh air from the bypass passage 46 will be described below.

  For example, when the engine 10 is decelerated, the intake air containing a high ratio of EGR gas flows into the combustion chamber 14 and the oxygen concentration decreases, so the engine 10 may misfire. In order to prevent this, the bypass flow rate control valve 48 is opened. As a result, fresh air can be directly introduced into the combustion chamber 14 as auxiliary air. As a result, misfire during deceleration of the engine 10 can be prevented.

[Configuration of air volume estimation model]
FIG. 2 is a functional block diagram showing an air amount estimation model in which the behavior of air in the engine 10 is modeled in the present embodiment. The air amount estimation model shown in FIG. 2 includes an AFM flow rate calculation unit 102, an AFM flow rate division unit 104, and an intake valve passage flow rate calculation unit 106. The intake valve passage flow rate calculation unit 106 includes an intercooler model M1, a throttle model M2, an intake pipe model M3, and an intake valve model M4.

  First, the configuration and function of each model provided in the intake valve passage flow rate calculation unit 106 will be described.

The intercooler model M1 is a physical model constructed based on a conservation law regarding air in the intercooler 38 in the intake passage 11. As the intercooler model M1, specifically, the following formula (1) based on the energy conservation law and the following formula (2) based on the flow rate conservation law are used. Here, P _ic is the pressure in the intercooler 38 (hereinafter referred to as intercooler pressure), T _ic is the intercooler temperature, V _ic is the intercooler volume, R is the gas constant, κ is the specific heat ratio, and m _afmcmp is the compressor 24 flow through (hereinafter, compressor flow rate), m _t is the gas passing through the throttle flow rate (hereinafter, the throttle flow rate), and, T _a is the ambient temperature. In the intercooler model M1, the compressor flow rate _{m Afmcmp,} a throttle flow rate _{m t} is input, the intercooler pressure _{P ics} is calculated according to equation (1) and (2). In addition, although the system of FIG. 1 is provided with an air bypass valve, it is assumed here that the air bypass valve is closed.

As the throttle model M2, the following expressions (3) and (4) are used. Here, mu is the opening area when the flow coefficient, A _t is the throttle opening degree TA, the P _m is the intake pipe pressure. P _m / P _ic is the pressure ratio before and after the throttle. In the throttle model M2, the throttle opening degree TA, the intercooler pressure _{P ics,} the intake pipe pressure _{P m} and the like are input, the throttle flow rate _{m t} is calculated according to equation (3) and (4).

The intake pipe model M3 is a physical model constructed based on a conservation law relating to air in the intake pipe. Specifically, the following equation (5) based on the energy conservation law and the following equation (6) based on the flow rate conservation law are used as the intake pipe model M3. _mc is a flow rate of gas sucked into the cylinder through the intake valve (hereinafter referred to as an intake valve passage flow rate), and _Tm is an intake pipe temperature. In the intake pipe model M3, the throttle flow rate m _t , the intake valve passage flow rate _{mc, and the} like are input, and the intake pipe pressure P _m is calculated according to the equations (5) and (6). In addition, although the system of FIG. 1 is provided with the EGR valve 32, it is assumed here that the EGR valve 32 is closed.

Intake valve model M4 is a test-based model examined the relationship between the intake valve passing flow m _c and the intake pipe pressure P _m. The relationship between the intake valve passage flow rate _mc and the intake pipe pressure P _m can be approximated by a straight line. Therefore, specifically, the following equation (7) based on an empirical rule is used as the intake valve model M4. In the formula (7), a and b are constants determined according to the engine speed. In the intake valve model M4, the intake pipe pressure _Pm is input, and the intake valve passage flow rate _mc is calculated according to the equation (7).

  Next, the AFM flow rate dividing unit 104 will be described with reference to FIG.

  FIG. 3 is a diagram showing the AFM flow rate dividing unit 104 in detail. The AFM flow dividing unit 104 includes a bypass flow control valve model M5 and an air flow meter model M6.

The bypass flow control valve model M5 is a physical model constructed based on the relationship between the opening degree of the bypass flow control valve 48 and the flow rate. Specifically, the following equation (8) is used as the bypass flow control valve model M5. Various calculated values are input to the bypass flow rate control valve model M5 as shown in FIG. Here, mu is the flow _{coefficient, A ISC} opening area of the bypass flow control valve 48, R is the gas constant, is _{P m} intake manifold _{pressure, P AC} cleaner after pressure, the _{T a} is the ambient temperature. In the bypass flow control valve model M5, the bypass flow control valve passage flow rate m _ISC is calculated according to the equation (8).

The air flow meter model M6 is a model of the response characteristics of the air flow meter 50. The air flow meter model M6 is used to calculate the bypass flow control valve passage flow rate m _ISC calculated by the bypass flow control valve model M5 as the air flow. Conversion to the measurement value of the meter 50 is performed. Thereby, an air flow rate having a time delay corresponding to the response delay of the air flow meter 50 is obtained. In this manner, in the air flow meter model M6, the bypass flow rate m _afmisc is calculated.

  The bypass flow rate calculated by the air flow meter model M6 is input from the AFM flow rate dividing unit 104 to the intake pipe model M3 of the intake valve passage flow rate calculating unit 106.

Further, in the AFM flow rate dividing unit 104 of FIG. 3, the calculation unit indicated by X calculates the difference between the air flow meter flow rate calculated by the AFM flow rate calculation unit 102 and the bypass flow rate calculated by the air flow meter model M6. This difference is the compressor flow rate m _afmcmp . The calculated compressor flow rate is input to the intercooler model M1 of the intake valve passage flow rate calculation unit 106.

  Next, how the air flow meter flow rate, the compressor flow rate, and the bypass flow rate change when the engine 10 is decelerated will be described with reference to FIG.

FIG. 4 is a diagram showing changes in various flow rates calculated by the air amount estimation model when the engine 10 is decelerated. The vertical axis in FIG. 4 _indicates the respective flow rates of the air flow meter flow rate m _afm , the compressor flow rate m _afmcmp , and the bypass flow rate m _afmisc , and the horizontal axis indicates time.

When the engine 10 decelerates, the throttle valve 40 is closed, so that the air flow meter flow rate m _afm decreases as shown in FIG. When the engine 10 starts decelerating, the bypass flow rate control valve 48 is opened to prevent misfire, so that the bypass flow rate m _afmisc increases overshoot as shown in FIG. 4 and is then controlled to a constant amount. . This constant amount of control is performed by the bypass flow rate control valve 48. The difference between the air flow meter flow rate m _afm and the bypass flow rate m _afmisc is the compressor flow rate m _afmcmp .

[Improved accuracy of intake flow rate]
In order to explain the improvement of the estimation accuracy of the intake valve passage flow rate by the air amount estimation model of the present embodiment, first, a comparative example will be described using FIG. 6 and FIG.

  FIG. 6 is a functional block diagram showing an air amount estimation model in which the behavior of engine air is modeled in the comparative example. The air amount estimation model in the comparative example does not have the AFM flow rate dividing unit 104 included in the air amount estimation model in the present embodiment. For this reason, the air flow meter flow rate is directly input to the intercooler model M1. Note that the comparative example and this embodiment differ only in whether or not the AFM flow rate dividing unit 104 is provided, and the configuration of the engine is the same.

  FIG. 7 is a diagram showing time-series changes in various flow rates calculated by the air amount estimation model in the comparative example. In addition, each flow volume shown by (b), (c), (d), (e) of FIG. 7 is a flow volume calculated by the air amount estimation model in the comparative example.

  FIG. 7A shows opening and closing of the bypass flow rate control valve 48 in the comparative example. From the time when the bypass flow rate control valve 48 is opened, each of the bypass flow rate, the AFM flow rate, and the intake valve flow rate changes.

  FIG. 7B shows changes in the compressor flow rate in the comparative example. The compressor flow rate is constant without being affected by the opening / closing of the bypass flow rate control valve 48.

  (C) of FIG. 7 has shown the change of the bypass flow volume in a comparative example. The change in the bypass flow rate in the comparative example is linked to the opening and closing of the bypass flow rate control valve 48.

  (D) of Drawing 7 shows change of AFM (air flow meter) flow volume in a comparative example.

  FIG. 7E shows the change in the intake valve passage flow rate in the comparative example. As shown in FIG. 7E, the calculated value of the intake valve flow rate (solid line) is delayed compared to the actual value of the intake valve flow rate (broken line). This is because the actual value of the intake valve flow rate increases because auxiliary air flows in when the bypass flow rate control valve 48 is opened, but the calculated value does not take this auxiliary air component into consideration.

  Next, the estimation accuracy of the intake valve passage flow rate based on the air amount estimation model of the present embodiment will be described with reference to FIG. 5, focusing on the differences from the comparative example.

  FIG. 5 is a diagram showing time-series changes of various flow rates calculated by the air amount estimation model in the present embodiment.

  (C) of FIG. 5 has shown the change of the bypass flow volume in this embodiment. The solid line in FIG. 5C is the bypass flow rate calculated by the air flow meter model M6. The broken line in (c) of FIG. 5 is the bypass flow control valve passage flow rate calculated by the bypass flow control valve model M5. The bypass flow rate rises more slowly than the bypass flow rate control valve passage flow rate. This is because, in the air flow meter model M6, the flow rate passing through the bypass flow control valve is converted to an air flow meter equivalent.

  (E) of FIG. 5 has shown the change of the intake valve passage flow rate in this embodiment. FIG. 5 (e) shows how the actual value of the intake valve passage flow rate and the calculated value change in the same way. Thus, according to the air amount estimation model in the present embodiment, there is no deviation between the actual value of the intake valve passage flow rate and the calculated value as shown in the comparative example. For this reason, the estimation accuracy of the intake valve passage flow rate can be improved. As a result, the controllability of the air-fuel ratio is improved and the emission can be maintained satisfactorily.

  Further, the air amount estimation model of the present embodiment has a length, a pipe diameter, and an actuator (compressor, I / C, throttle valve, etc.) attached to each passage in the intake passage 11 and the bypass passage 46. It can be applied even in different cases.

  In this embodiment, the AFM flow rate calculation unit 102 is the “air flow meter flow rate calculation unit” according to the first invention, and the AFM flow rate division unit 104 is the “bypass flow rate calculation unit” and “intake air” according to the first invention. In the “passage flow rate calculation means”, the intake valve passage flow rate calculation unit 106 is in the “intake valve passage air flow rate calculation means” according to the first aspect of the invention, and the intercooler model M1 and the throttle model M2 are in the “first direction”. The intake pipe model M3 and the intake valve model M4 correspond to the “second physical model” according to the second aspect of the present invention.

DESCRIPTION OF SYMBOLS 10 Engine 11 Intake passage 16 Intake valve 24 Compressor 36 Supercharging pressure sensor 38 Intercooler 40 Throttle valve 42 Intake pipe 44 Intake pipe temperature sensor 46 Bypass passage 48 Bypass flow control valve 50 Air flow meter 100 ECU
102 AFM flow rate calculation unit 104 AFM flow rate division unit 106 Intake valve passage flow rate calculation unit M1 Intercooler model M2 Throttle model M3 Intake pipe model M4 Intake valve model M5 Bypass flow rate control valve model M6 Air flow meter model

Claims (4)

A throttle disposed in the intake passage; an air flow meter attached upstream of the throttle; a bypass passage that bypasses the throttle and connects the downstream of the air flow meter and the upstream of the intake valve; and disposed in the bypass passage An intake valve passing air flow rate, which is a flow rate of air passing through the intake valve, is provided for an internal combustion engine having a bypass flow rate control valve, and the internal combustion engine is controlled based on the intake valve passing air flow rate. In the control device to control,
An air flow meter flow rate calculating means for calculating an air flow meter flow rate which is a flow rate of air passing through the air flow meter from an output of the air flow meter;
A bypass flow rate calculation means for calculating a bypass flow rate, which is a flow rate of air flowing through the bypass passage, based on an opening of the bypass flow rate control valve;
An intake passage flow rate calculation means for calculating an intake passage flow rate which is a flow rate of air flowing into the intake passage from the air flow meter flow rate and the bypass flow rate;
An intake valve passing air flow rate calculation means for calculating the intake valve passing air flow rate based on the intake passage flow rate and the bypass flow rate using a physical model of an intake system including the throttle;
A control device for an internal combustion engine, comprising: The physical model used by the intake valve passage air flow rate calculation means includes a first physical model that models an intake system from a branch point of the bypass passage to the throttle of the intake passage, and the intake passage passage It consists of a second physical model that models the intake system from the junction of the bypass passage to the intake valve,
The intake valve passage air flow rate calculation means includes:
Means for calculating a throttle flow rate that is a flow rate of air passing through the throttle from the intake passage flow rate using the first physical model;
Means for calculating the intake valve passing air flow rate from the total flow rate of the throttle flow rate and the bypass flow rate using the second physical model;
The control apparatus for an internal combustion engine according to claim 1, comprising: The bypass flow rate calculation means includes
Means for calculating a bypass flow rate control valve passing flow rate, which is a flow rate of air passing through the bypass flow rate control valve, using a bypass flow rate control valve model that models a relationship between an opening degree and a flow rate of the bypass flow rate control valve;
Means for converting the flow rate passing through the bypass flow control valve into a value equivalent to the measured value of the air flow meter using an air flow meter model that models the response characteristics of the air flow meter, and outputting the converted flow rate as the bypass flow rate;
The control apparatus for an internal combustion engine according to claim 1 or 2, characterized by comprising:   4. The internal combustion engine according to claim 1, wherein the internal combustion engine includes a compressor in the intake passage, and the bypass passage is branched from the intake passage upstream of the compressor. 5. Control device.

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