JPS61157741A - Detecting device of intake air quantity - Google Patents

Abstract

PURPOSE:To enable an intake air quantity to be correctly detected by a device though it is of simplified construction and at a low cost, by calculating the intake air quantity, after it is corrected by the atmospheric pressure, in accordance with the detection result of an intake pipe pressure, engine speed and a throttle opening. CONSTITUTION:An internal-combustion engine EG, having a throttle valve T in every intake pipe I in each cylinder, provides an intake pipe pressure detecting means M1, detecting a pressure in the intake pipe synchronously with respectively when intake is executed and no intake is executed in the intake pipe I, in the downstream side of the throttle valve T for a cylinder in quantity smaller than the number of cylinders. While the engine provides each detecting means M2, M3 detecting a speed and a throttle opening. And the engine, calculating in an intake air quantity calculating means M4 a reference intake air quantity from the intake pipe pressure and the speed to be corrected in accordance with an intake air quantity adjusting value calculated by the throttle opening and the speed and an atmospheric pressure correction value obtained by said adjusting value or the like, is constituted so as to calculated the intake air quantity.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an intake air amount detection device for detecting the intake air amount of an internal combustion engine, and particularly relates to an intake air amount detection device for detecting an intake air amount of an internal combustion engine, and particularly to a so-called intake air amount detection device in which the internal combustion engine has a throttle valve in the intake pipe of each cylinder. The present invention relates to an intake air amount detection device that detects the intake air amount of an independent intake type internal combustion engine.

[Prior art] Traditionally, internal combustion engines have been supplied with the optimum amount of fuel to operate them at a desired air-fuel ratio, and combustion timing has been controlled using optimum ignition timing. The intake air amount of the engine is calculated as an average value of the cylinders after detecting the intake pipe negative pressure using a pressure sensor, or is detected by an air 70 meter.

However, in recent years, the operational performance of internal combustion engines has been further improved.
In order to improve response such as acceleration response, so-called independent cylinder internal combustion engines have been proposed, in which a throttle valve is provided for each cylinder of the internal combustion engine.
Seki control technology is being researched and developed.

That is, independent intake internal combustion l! Since the I engine has a throttle valve for each cylinder, it not only has good response, but also
This eliminates pressure interference between cylinders, making it possible to operate the internal combustion engine more efficiently. On the other hand, in order to detect the amount of intake air in each cylinder, it is necessary to install an air 70 meter, pressure sensor, etc. for each cylinder, and the structure is 1! It was getting messy.

Therefore, as a device for detecting the amount of intake air for controlling an independent cylinder type internal combustion engine, a simple air 70 meter system is used, which has an air 70 meter installed at the point where each intake cylinder gathers upstream of the throttle valve. is the mainstream, and as a method for detecting intake pipe pressure, a method has been proposed in which a communication pipe is newly provided leading to each cylinder and the averaged pressure is detected.

[Problem to be Solved by the Invention 1] However, the above technology also has the following problems and is still not satisfactory.

In other words, the greatest advantage of the independent cylinder type internal combustion engine is improved response, but in the case where a 70 meter air meter is provided at the gathering point of each intake pipe, the 70 meter air meter acts as a resistance to the intake air. Therefore, it works to eliminate the above advantages.

Therefore, in order to control an independent cylinder type internal combustion engine, it is a more preferable technique to accurately detect the intake air amount from the intake pipe negative pressure. However, in the conventional technology in which a communication pipe is provided for each cylinder to detect intake air pressure, a new problem arises in that pressure interference between cylinders occurs through the communication pipe, and the structure is There was also a cost problem due to the complexity.

The present invention has been made to solve the above problems,
Even for independent cylinder internal combustion engines, it is advantageous in that it takes advantage of the characteristics of the independent cylinder type, has a simple structure, and can accurately detect the intake air amount by taking into account the influence of atmospheric pressure. The purpose of the present invention is to provide an intake air amount detection device that provides a

[Means for solving the problem] In an intake air detection device for detecting the intake air amount of an internal combustion engine EG having a throttle valve T for each intake pipe i of each cylinder, the number of intake air is smaller than the number of cylinders of the internal combustion engine EG. An intake pipe that is provided downstream of each throttle valve T for several cylinders and detects the pressure inside the intake pipe in synchronization with each time when the intake pipe is performing intake and when the intake pipe is not performing intake. pressure detection means M1, rotation speed detection means M2 for detecting the rotation speed of the internal combustion engine EG, throttle degree detection means M3 for detecting the opening degree of the throttle valve T, and -2 intake pipe pressure detection means M1. An intake air amount calculation means M4 that calculates an intake air amount after atmospheric pressure correction of the internal combustion engine EG from the detection result, the detection result of the rotation speed detection means M2, and the detection result of the throttle coincidence detection means M3. The gist of the invention is an intake air amount detection device characterized by the following features.

The intake pipe pressure detection means M1 in the present invention detects the pressure of the intake pipe (2) at least twice: when the cylinder in which the detection means is provided is in the intake stroke, and when the cylinder is not in the intake stroke. For example, it may be configured to detect the output of an intake pressure sensor provided in a normal internal combustion engine in synchronization with the internal combustion engine EG slope angle. Under special conditions such as when the internal combustion engine EG is always at a constant rotation speed, it is sufficient to have a configuration in which the output of the intake pressure sensor is taken in at predetermined intervals.

Further, the rotation speed detection means M2 is for detecting the rotation speed of the internal combustion engine EG. This can be easily configured, for example, by calculating the number of outputs per unit time of the crank angle detection means conventionally provided in the internal combustion engine EG. Furthermore, the predetermined crank angle shown in the example for synchronizing the detection of the intake pipe pressure detection means M1 can be easily detected by this rotation speed detection means M2 and the cylinder discrimination sensor conventionally provided in the internal combustion engine 111EG. .

The throttle degree detection means M3 detects the opening degree of the throttle valve T provided in the intake pipe (2) of each cylinder.

If the throttle valves T are all controlled independently and their opening degrees are independent, the opening degree of each throttle valve T is detected, and if all the throttle valves T are linked, only the opening degree of one of them is detected. A device that detects is sufficient.

The intake air amount calculation means M4 is the intake pipe pressure detection means M
1. Rotation speed detection means M2 and throttle coincidence detection means M
The intake air amount of the internal combustion engine gIEG with atmospheric pressure correction is calculated from the detection result of step 3. Therefore, for example, a device constituting a hardware arithmetic circuit that inputs the detection results of the above three means,
Alternatively, a number of configurations are possible, such as configuring the hardware arithmetic circuit with software using an arithmetic device such as a microcomputer, or configuring a map that is prepared in advance and searching for the map in order to increase the calculation speed. It is.

[Function] That is, the intake air amount detecting device of the present invention having the above configuration includes an intake pipe pressure detecting means M1, a rotation speed detecting means M2, and a throttle speed detecting means M3 provided in an independent intake type internal combustion engine EG. Based on the detection result, the intake air amount calculation means M4 calculates the amount of intake air corrected for atmospheric pressure.

Conventionally, the amount of intake air has been calculated from the intake pipe pressure and rotational speed during the intake stroke, and since the intake pipe pressure at times other than the intake stroke is equal to atmospheric pressure, the intake pipe pressure at that time is It is known to detect pressure and correct the calculated intake air amount to atmospheric pressure. Moreover, the internal combustion engine E of the present invention
G is an independent intake type internal combustion engine, and the intake pipe pressure detection means M1 is provided in only one cylinder. Therefore, with the above-mentioned conventional technique, it is possible to calculate the amount of intake air with atmospheric pressure correction applied to an instant when one cylinder is in the intake stroke.

However, knowing the intake air amount of the internal combustion engine EG is necessary to control the fuel injector, ignition timing, etc. of the internal combustion engine EG, and simply knowing only 11 periods within one cycle is insufficient.

Therefore, the intake air amount calculation means M4 of the present invention further takes into account the detection results of the throttle coincidence detection means M3. If the fluctuations in the throttle R degree and the rotational speed are known, it is possible to calculate the fluctuation value in the intake air amount of the internal combustion engine EG from these two fluctuation values. Therefore, the intake air amount calculation means M4 uses the instantaneous actually measured intake air amount as a reference, and the intake air amount at a time other than the instantaneous moment is determined by increasing or decreasing the intake air amount using the detection result of the throttle coincidence detection means M3. By calculating , it is possible to constantly calculate the amount of intake air.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, the present invention will be described in detail by giving examples.

[Example 1] Fig. 2 shows the intake air amount detecting device according to the example 4.
1 is a schematic diagram of a control system for a cylinder independent intake internal combustion engine.

In the figure, numeral 10 indicates a four-cylinder engine, and the intake pipe 11 of each cylinder communicates with a throttle valve 12 that is linked to an accelerator pedal (not shown) and a fuel tank (not shown), and fuel is injected toward the intake pipe. fuel injection valve 1
3 is provided.

The cylinders are arranged in the order of the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder from the top of the drawing. Further, the ignition plug 14 provided for each cylinder is appropriately supplied with high voltage by a distributor 15 to determine the ignition timing. A throttle opening sensor 16 detects the opening of the throttle valve 12 and outputs an analog output proportional to the opening of the throttle valve 12.

In this embodiment, an intake pressure sensor 17 consisting of a pressure sensor for detecting intake pipe negative pressure is provided downstream of the throttle valve 12 in the intake pipe 11 of the first cylinder. Further, 18 represents a water temperature sensor that detects the cooling water temperature of the internal combustion engine 10, 19 represents an oxygen sensor that detects the oxygen concentration in the exhaust gas of the internal combustion engine 10, and 20 represents an intake temperature sensor that detects the intake air temperature.

The outputs of these various sensors and the operating states of various devices are centrally processed by the electronic control unit @30.

Electronic 11JtlO4! [30, as shown in the figure, is composed of a logical operation circuit centered on a microcomputer, and is connected to a key switch 22 from an on-vehicle battery 21.
It operates by receiving power supply through. 31 is the central part of the computer, a CPU that executes various calculations, and RO
33 is a RAM for temporarily storing data, which performs processing according to a system program and map, which will be described later, stored in M32. Reference numeral 34 indicates the outputs from the various sensors described above, the throttle opening sensor 16, the intake pressure sensor 17, the water temperature sensor 18, the oxygen sensor 19, and the intake temperature sensor 20, and the cylinder discrimination signal from the distributor 15, depending on the rotation angle of the crank angle. This is an input board for inputting rotation angle signals, including an A/D converter, waveform shaper, etc.
The information necessary for 1 is output as appropriate. 35 is an output boat, which controls the valve opening timing and time for the fuel injection valve 13 of each cylinder.
It outputs according to the calculation result of U31, and also outputs the spark plug 14.
A signal that determines the ignition timing is output to the distributor 15. Each component of the electronic control unit 30 is connected by a data and address bus 36.

3 (A>, (B)) and FIG. 4 show flowcharts of the intake air amount detection program stored in the ROM 32.

FIGS. 3(A) and 3(8) show a flowchart of a routine for determining the timing to take in the sensor output.

(A) In the diagram, CP is synchronized with the crank angle of the internal combustion engine 10.
A routine repeatedly executed at U31 manages two timings in one cycle (two rotations of the crankshaft) for receiving the output of the intake pressure sensor 17. First, when a predetermined crank angle is reached and the CPU 31 enters the processing of this routine, it is determined in step 100 whether or not it is the timing to take in the intake pipe pressure PS. The PS intake timing means that when the horizontal axis is the crank angle based on the TDC of the first cylinder, as shown in the timing chart (A) of FIG. This refers to the timing at which an output indicating a negative pressure situation is generated in the engine, and the timing at which the intake pipe pressure becomes equal to atmospheric pressure below the intake stroke. Therefore, as is clear from the timing chart of FIG. 5(A), the period (approximately 0
'GA ~ 360' OA) and the period of continuing to output a constant value! ! (approximately 360° CA to 720 eCA), in this embodiment, capture of the sensor output PS is started at approximately 160° OA and 680° OA. In this step 100, the crank angle of the internal combustion engine 10 is approximately 160
' If it is determined that it is OA or 680° OA, A/D conversion processing of the output of the intake pressure sensor 17 is started in the next step 110, and the output of the intake pressure sensor 17 is A/D converted in the input boat 34. and its value PSAD1 (16
ps value at 0°OA -), PSAD2 (680@OA
A series of processes such as temporarily storing the PS value (FIGS. 5B and 5C) in a buffer are started. Also,
If the crank angle is other than about 160° OA or 680° CA, this routine is ended and another routine is executed without starting the process of step 110 as described above.

FIG. 3(B) shows the routine of the process of taking in the output (TA) of the throttle opening sensor 16, which is repeatedly processed by the CPU 31 every time a predetermined time elapses. First, when the processing of the CPU 31 moves to this routine, step 20
A predetermined period of time (T [
msl) has elapsed. And T
[Step 210 is processed only when it is determined that msl has elapsed; otherwise, this routine ends. This step 210 is the throttle opening sensor 16
The output TA of ADI! tli (TAAD)
It controls the start of a series of processes for storing TAAD to a predetermined address, and the import of TAAD is started. Fifth
Figure (E) is a timing chart for capturing the output of the throttle opening sensor TA. As shown in the figure, the value TAAD obtained by AD converting TA is fetched every predetermined period T [msl. This predetermined period T[msl is a value smaller than the period during which the AD conversion value PSAD of the intake pipe negative pressure is taken in, and TAAD is taken in at a higher frequency than the frequency of taking in PSAD.

FIG. 4 shows the main routine of this embodiment, in which the intake air amount Q of the internal combustion engine mio is calculated.

This routine is repeatedly executed by the CPU 31 at predetermined time intervals. The CPU 31 is used to process this routine.
When this is entered, it is first determined in step 300 whether the A/D conversion of the output PS of the intake pressure sensor 17 (the series of processes started in step 110 described above) has been completed, and whether the latest PS value has been imported. A judgment will be made. If it is determined in this step that the A/D conversion of the latest PS has not been completed, the process proceeds to step 380, which will be described later, and if the A/D conversion has been completed 6, the next step 310 is processed. In step 310, the A/D of the output ps of the intake pressure sensor 17 is
A conversion value PSAD is calculated within CPL 131. Then, this A/D conversion value PSAD value is 160° of the crank angle.
A determination is made as to whether it is detected in synchronization with either OA or 680°OA (step 320), and 160'O
If it is the notator at time A, steps 330 to 350
The reference intake air IQPMC is calculated through the process, and if the data is 6801CA, atmospheric pressure correction coefficients KPM and KTA for QPM and QTA, which will be described later, are calculated through the processes at steps 360 and 370. First Q
Calculation of PMC will be explained. PSADI [calculated in step 310 is a value indicating the negative pressure situation of the intake air, and is set to the variable PSADI (step 330).
, the intake air IQPM is calculated from the value PSAD1 and the rotational speed NE of the internal combustion engine 10 (step 340).

This calculation is no different from the conventional calculation of the intake air amount Q, and is calculated by the CPU 31 or by the RO
It is obtained by searching the map prepared in M32. In the subsequent step 350, the intake air amount QPM obtained in this manner is multiplied by the atmospheric pressure correction coefficient KPM to calculate the reference intake air amount QPMC. On the other hand, the atmospheric pressure correction coefficient KTA of the intake air increase/decrease IQTA is calculated based on the atmospheric pressure correction coefficient KPM used when calculating the reference intake air amount QPMC and the throttle opening degree TA, which will be described later.
Steps 360 and 370 execute the calculation of
It is. First, in step 360, the PSAD value calculated in step 310 is set to the variable PSAD2, and in the subsequent step 370, two atmospheric pressure correction coefficients KPM and KT are set.
A is calculated. These two atmospheric pressure correction coefficients K
P.M.

KTA is also obtained by calculation by the CPU 31 or by searching each map prepared in the ROM 32.

When atmospheric pressure changes, the amount of intake air changes even under the same intake pipe pressure or throttle opening. Therefore, this change is corrected by converting the extent of this change into a number in advance and calculating it by the CPU 31, or by preparing it as a map and executing the search.

After QPMC, KPM, and KTA are determined in this way, step 380 is then executed.

Here, the same process as step 300 described above is executed, and it is determined whether the throttle opening TA acquisition process in step 6 in step 210 of FIG. 3(B) has been completed and the latest TA value has been obtained. However, if the process has not been completed, step 450, which will be described later, is executed, and only when the process has been completed, the series of processes from step 390 to step 440 are executed. The processing from step 390 to step 440 represents the processing for calculating the range increase value ΔQTA of the reference intake air 111QPMc calculated at step 350 described above.

First, in step 390, an AD conversion value TAAD of the throttle opening degree TA is calculated and subjected to the processing of CPtJ31. Then, this value TAAD and the rotation speed N of the internal combustion engine 10
The intake air amount QTA, which is calculated from the throttle opening TA, is calculated from E (step 400). Calculation of QTA is also performed by direct calculation processing, similar to the above-mentioned QPM, or by searching a map. In the following step 410, the latest atmospheric pressure detection result calculated in the step 370 (
Correction coefficient KTA obtained from PSAD2) and this QTA
The intake air amount QTAC is calculated from the throttle opening TA corrected for the atmospheric pressure. In the next step 420, the timing immediately before the TAAD calculated in step 390 executes A/D conversion of PSADl,
That is, it is determined whether or not the timing is immediately before the crank angle [160' OA. As shown in FIGS. 5(B) and (E), PSADl is calculated every 720'OA of crank angle, and TAAD is calculated every predetermined time T[m'sl, and TAAD is always calculated. Frequency is PSA
This is set higher than the calculation frequency of D. Therefore, TAAD is always calculated very close to (within a small time difference) the PSADl calculation timing. Therefore, in this step, it is determined whether QTAC has been calculated using TAAD at the timing immediately before the PSADl timing. And this QTA
Step 430 is executed only when C is the timing immediately before PSADl, and the value of QTAC is set to the variable QTA.
If it is set to B, otherwise the process proceeds to step 440. FIG. 5(E) shows the relationship between QTAC and QTAB.

Step 440 is a step for calculating an increase/decrease value ΔQTA in the intake air amount, and ΔQTA is calculated from the latest QTACD value and QTAB value using the following equation.

ΔQTA-QTAC-QTA8 QTAB is calculated immediately before the QPMC calculation as described above, and the influence (QTAB) of the throttle opening degree TA on the intake air amount is already reflected in the value of QPMC. However, if the throttle valve 12 is controlled to open or close from the time of QPMC calculation, the intake air amount and rotational speed NE will naturally change, but the change in the intake air amount at this time will be as follows: ) cannot be calculated. Therefore, if information on the intake air amount of the internal combustion engine 1o is required during the time when the intake air amount cannot be detected, the difference between QTAC and QTAB calculated from the throttle opening TA and rotational speed NE at that time, , how much throttle opening TA and rotation speed N compared to the time of QPMC calculation
It is calculated whether there is a change in the amount of intake air based on a change in E.

Then, add this 1ll (ΔQTA) to QPMC (
・Step 450) Therefore, the intake air IQ of the internal combustion engine 1o
(FIG. 5(F)) is constantly calculated.

The shaded area in FIG. 5(E) represents the correction width (ΔQTA) of the intake air amount based on the throttle opening TA and the rotational speed NE. Intake air IQ calculated in this way
is then used in various existing controls. For example, it can be widely used to calculate the fuel injection amount to maintain the air-fuel ratio of the internal combustion engine 10 at a desired value, and to calculate the ignition timing to control the torque and emissions of the internal combustion engine 10.

FIG. 6 shows an application example in which the ignition timing of the internal combustion engine 10 is determined using the intake air IQ detected by the intake air amount detection device of this embodiment. FIG. 6 is a flowchart for determining the ignition timing.

The ignition advance angle calculation routine shown in FIG. 6 is repeatedly executed as a part of the main routine for controlling the internal combustion engine 10 or as an independent routine, and determines the best ignition timing for each cylinder. Calculate whether the operation of the internal combustion engine can be ensured.

First, in step 500, it is determined whether it is the current time to calculate the ignition timing. It is determined from the crank angle, etc. whether any cylinder of the internal combustion engine is approaching the time when it requires ignition. Then, only when it is determined that it is time to calculate the ignition timing, the processes of steps 510 to 530 are executed, and otherwise, this routine is ended. In step 510, the current rotational speed NE and intake air amount Q of the internal combustion engine 10 are detected. Internal combustion engine T required to calculate ignition timing! It detects the operating status of A10. Here, the rotation speed NE can be detected at all times by the rotation angle signal from the distributor 15, and the calculation result of the above-described embodiment is used for the intake air IQ. Therefore, the routine shown in FIG. 4 of the embodiment is executed immediately before the execution of this routine, and the internal combustion engine 10
The intake air amount Q is required. Next, in step 520, a known map (not shown) for calculating ignition timing is searched from the above two values NE and Q, and ignition timing is calculated. Thereafter, in step 530, the map search result is stored in the RAM 33, and ignition is performed according to the information in the RAM 33 by an ignition execution routine (not shown).

In this way, the intake air mQ calculated in the above-mentioned embodiment is no different from the intake air amount that has conventionally been used as a control parameter for the internal combustion engine 10, and can be widely used as a parameter for all existing controls. .

[Effects of the Invention] As described above in detail with reference to embodiments and application examples, the intake air amount detection device of the present invention detects the intake air amount of an internal combustion engine having a throttle valve for each intake pipe of each cylinder. In the intake air amount detection device, the intake air amount detection device is provided on the downstream side of each throttle valve 1 to 1 for a cylinder whose number is smaller than the number of cylinders of the internal combustion engine, and is installed on the downstream side of each of the throttle valves 1 to 3 for cylinders whose number is smaller than the number of cylinders of the internal combustion engine, and when the intake pipe is performing intake, and when the intake pipe is not performing intake. intake pipe pressure detection means for detecting the intake pipe internal pressure in synchronization with each other when the internal combustion engine is not in use; rotation speed detection means for detecting the rotation speed of the internal combustion engine; and throttle coincidence detection means for detecting the opening degree of the throttle valve. and intake air amount calculation for calculating an intake air amount after atmospheric pressure correction of the internal combustion engine from the detection result of the intake pipe pressure detection means, the detection result of the rotation speed detection means, and the detection result of the throttle coincidence detection means. It is characterized by comprising means.

Therefore, it is possible to always accurately detect the intake air amount of an independent cylinder internal combustion engine by even performing atmospheric pressure correction, although the device has a simple structure and is low in cost. Furthermore, since no device such as an air 70 meter that creates resistance to the intake air is used for this detection, the characteristics of an independent cylinder type internal combustion engine can be fully utilized, and pressure interference between each cylinder can be avoided. This makes it an extremely excellent intake air amount detection device.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of the present invention, FIG. 2 is a schematic configuration diagram of an embodiment, FIGS. 3 (A), (B), and 4 are control flow charts thereof, and FIG. 5 is a timing chart thereof. 6th
The figure shows an application example of the intake air amount determined in the example. Ml...Intake pipe pressure detection means M2...Rotational speed detection means M3...Throttle sameness detection means M4...Intake air! Calculation means 12... Throttle valve 16... Throttle opening sensor 17... Intake pressure sensor 14... Spark plug

Claims (1)

[Scope of Claims] 1. In an intake air amount detection device for detecting the intake air amount of an internal combustion engine having a throttle valve for each intake pipe of each cylinder, each throttle for a number of cylinders smaller than the number of cylinders of the internal combustion engine is provided. an intake pipe pressure detection means that is provided downstream of the valve and detects the pressure inside the intake pipe in synchronization with the intake pipe when the intake pipe is performing intake and when the intake pipe is not performing intake; and the rotation of the internal combustion engine. a throttle opening detection means for detecting the opening of the throttle valve; a detection result of the intake pipe pressure detection means, a detection result of the rotation speed detection means, and the throttle degree detection means; An intake air amount detection device comprising: intake air amount calculation means for calculating an intake air amount after atmospheric pressure correction of the internal combustion engine from the detection result of the means. 2. Reference intake in which the intake air amount calculation means calculates a reference intake air amount from the detection result of the intake pipe pressure detection means synchronized when the intake is being performed and the detection result of the rotation speed detection means. an air amount calculation section; an intake air amount increase/decrease calculation section that calculates an increase/decrease value of the intake air amount from the detection result of the throttle degree detection means and the detection result of the rotation speed detection means; and the reference intake air amount calculation section. an atmospheric pressure correction section that corrects the calculation result of the intake air amount increase/decrease calculation section and the calculation result of the intake air amount increase/decrease calculation section based on the result of detection synchronized with the intake pipe pressure detection means when the intake is not performed; and the atmospheric pressure correction section. 2. The intake air amount detection device according to claim 1, further comprising an intake air amount calculation section that calculates the intake air amount of the internal combustion engine from the reference intake air amount corrected by the intake air amount and the increase/decrease value of the intake air amount.