JPH04246258A - Controller for engine - Google Patents

Abstract

PURPOSE:To allow the fuel feed quantity to each cylinder of an engine to correspond to the intake air quantity supplied to each cylinder with high precision by properly varying the fuel feed quantity to each cylinder of the engine to vary, following the variation of the intake air quantity for each cylinder. CONSTITUTION:When an engine 1 is in a stationary operation state, a control unit 40 estimates the intake air quantity at the end time point of the intake stroke on the basis of the intake air quantity at the first time point before the completion of the intake cycle of one cylinder, and when the engine 1 is in an excessive operation state, the control unit 40 estimates the intake air quantity at the completion time of the intake cycle, on the basis of the intake air quantity at the second time point later than the first time point before the completion of the intake cycle of one cylinder, and the combustion state in the cylinder of the engine 1 which corresponds to the estimated intake air quantity is controlled.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device that improves the accuracy of controlling combustion conditions in cylinders in an engine by controlling fuel supply in accordance with the operating conditions of the engine.

0002

2. Description of the Related Art In engines installed in vehicles, the amount of fuel supplied to each cylinder is made to appropriately correspond to the amount of intake air supplied to each cylinder under various operating conditions. It is desirable that the mixture of fuel and intake air has good combustibility, etc. Therefore, for example, when transitioning from a steady state of operation to an accelerated state of operation, the air-fuel mixture will follow the increase in the amount of intake air. Fuel supply control is performed to increase the amount of fuel supplied. Fuel is often supplied to the engine intermittently by a fuel injection valve placed near the intake port in the intake passage forming section, but the amount of fuel supplied increases as the amount of intake air increases. When performing fuel supply control to increase the amount of fuel, in order to improve the responsiveness to changes in the fuel supply state and avoid a delay in increasing the amount of fuel supplied with respect to the increase in the amount of intake air, for example, Japanese Patent Application Laid-Open No. 1986-60- 11
As shown in Japanese Patent Laid-open No. 6840, fuel injection is supplied by a fuel injection valve multiple times during one intake stroke for each cylinder, or, for example, Japanese Patent Laid-Open No. 61-1
As shown in Publication No. 06946, when the engine is in a steady operating state and there is no problem of delay in increasing the amount of fuel supplied, the fuel supply is adjusted to sufficiently vaporize the fuel injected from the fuel injection valve. This is done when each cylinder is in a state other than the intake stroke, but if the engine is to be placed in an accelerated operation state where a delay in increasing the amount of fuel supply becomes a problem, increase the amount of fuel supplied quickly. To achieve this, it has been proposed that the fuel supply be carried out when each cylinder is on its intake stroke.

0003

[Problems to be Solved by the Invention] However, as described above, when fuel supply control is performed with the intention of avoiding a delay in increasing the amount of fuel supplied in response to an increase in the amount of intake air, It is assumed that the increase in the supply amount follows the increase in the amount of intake air, and in this case, it is guaranteed that the amount of fuel supplied to each cylinder will accurately match the amount of intake air supplied to each cylinder. Therefore, there is a risk that the air-fuel mixture taken into each cylinder from the intake passage may not exhibit good combustibility.

[0004] In view of the above, the present invention aims to appropriately track the amount of fuel supplied to each cylinder to changes in the amount of intake air to each cylinder when controlling the combustion state within the cylinders of an engine in accordance with the operating state of the engine. An object of the present invention is to provide an engine control device that can change the amount of fuel supplied to each cylinder and accurately match the amount of intake air supplied to each cylinder.

[0005]

[Means for Solving the Problems] In order to achieve the above-mentioned object, an engine control device according to the present invention, as shown in the basic configuration in FIG. , an operating state for determining whether the operating state of the engine detected by the operating state detection means is a steady operating state in which state changes are relatively small or a transient operating state in which state changes are relatively large; the engine at the end of the intake stroke, based on the determining means and the change factors related to the operating state of the engine at a first time period before the end of the intake stroke during each stroke cycle for one cylinder in the engine; A first prediction for predicting a change factor related to the operating condition or the engine at a second time period later than the first time period and before the end of the intake stroke during each stroke cycle for one cylinder in the engine. a second prediction means for predicting a change factor related to the operating state of the engine at the end of the intake stroke based on a change factor related to the operating state of the engine; and a combustion state control means. When the operating state determining means determines that the operating state of the engine is a steady operating state, the state control means causes the predicting means to perform the first prediction, and the engine operation predicted by the first prediction is performed. The combustion state in the cylinders of the engine is controlled according to the change factors related to the state, and when the operating state determining means determines that the operating state of the engine is in a transient operating state, the predicting means includes a second The present invention is configured to perform prediction and to control the combustion state in the cylinders of the engine in accordance with changing factors related to the operating state of the engine predicted by the second prediction.

[0006]

[Operation] In the engine control device according to the present invention configured as described above, the combustion state in the cylinder is controlled in accordance with a changing factor related to the operating state of the engine, such as the amount of intake air. In this case, when the engine is in a steady state of operation, the intake stroke is determined based on the changing factors related to the operating state of the engine at a first time period before the end of the intake stroke during each stroke cycle for one cylinder in the engine. A first prediction is made to predict the change factors related to the operating state of the engine at the end of the process, and when the engine is in a transient operating state, such as an accelerated operating state, each Involves in the operating state of the engine at the end of the intake stroke based on the changing factors that affect the operating state of the engine at a second time period, which is before the end of the intake stroke in the stroke cycle and is later than the first time period. A second prediction is made to predict the change factors that will occur, and the change factors related to the engine operating state at the end of the intake stroke predicted by the first prediction side or the second prediction, for example, the intake stroke. The combustion state within the cylinder is controlled according to the amount of air.

[0007] As a result, the internal combustion state of each cylinder can be controlled by adjusting the amount of fuel supplied to each cylinder not only when the engine is in a steady operating state but also when the engine is in a transient operating state such as an accelerating operating state. This is done in a state in which the amount of air can be changed appropriately to follow changes in the amount of air, and the amount of fuel supplied to each cylinder can be accurately matched to the amount of intake air supplied to each cylinder.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an example of an engine control system according to the present invention together with the main parts of a 12-cylinder V-type engine to which it is applied.

The engine body 1 shown in FIG. 2 has first and second cylinder banks 2 and 3 that are arranged opposite to each other.
Six cylinders 11-16 arranged in series and six cylinders 17-22 arranged in series are provided, respectively. Each of the cylinders 11 to 22 has a spark plug 4 in a combustion chamber formed above a piston disposed inside the cylinder.
The combustion chamber is communicated with a surge tank 25 forming a common intake passage 23 via an individual intake passage in which a fuel injection valve 6 is disposed. The common intake passage 23 includes a throttle valve 27 and an air flow meter 2 on the upstream side of the surge tank 25.
9 and an air cleaner 30 are arranged in this order.

The first cylinder bank 2 includes cylinders 1
Spark plugs 4 arranged at each of 1 to 16 and 17 to 22
(The connection wiring is not shown in the diagram.)
, the cylinders 11-1 are rotationally driven by the crankshaft.
A distributor 5 for supplying ignition pulses to the ignition plugs 4 disposed at each of the spark plugs 6 and 17 to 22 is attached. Cylinders 11-16 and 17-2
The order of ignition timing in No. 2 is, for example, cylinder 11→
Cylinder 17 → Cylinder 15 → Cylinder 21 → Cylinder 13 → Cylinder 19 → Cylinder 16 → Cylinder 22 → Cylinder 12 → Cylinder 18 → Cylinder 14 → Cylinder 2
It is set to 0.

Further, the combustion chambers formed above each of the cylinders 11 to 16 are communicated with the branch exhaust passage 8, and the combustion chambers formed above each of the cylinders 17 to 22 are communicated with the branch exhaust passage 8. It is communicated with passage 9.

In addition to the above-described configuration, the engine main body 1 is provided with a control unit 40. The control unit 40 has a detection output signal Sc representing the crank rotation angle obtained from the crank angle sensor 31 and the rotation speed sensor 32 provided in the distributor 5, a detection output signal Sn representing the engine rotation speed, and a detection output signal Sn obtained from the air flow meter 29. A detection output signal Sa representing the intake air flow rate and a detection output signal Sx representing other factors such as cooling water temperature indicating the operating state of the engine are supplied. Then, the control unit 40 performs fuel injection control for each fuel injection valve 6 based on each of these detection output signals.

When the control unit 40 performs fuel injection control, a basic fuel injection amount is set based on the intake air flow rate and engine rotational speed respectively indicated by the detection output signals Sa and Sn, and the basic fuel injection amount is The final fuel injection amount is determined by being corrected by a correction amount that is set based on the cooling water temperature and the like represented by the detection output signal Sx. Then, an injection drive pulse signal CP having a pulse width corresponding to the determined final fuel injection amount is formed, and is applied to the fuel injection valves 6 corresponding to the cylinders 11 to 16 and 17 to 22, respectively. The ignition timings 16 and 17 to 22 are sequentially supplied in accordance with the order of the ignition timings.

Further, based on the intake air flow rate indicated by the detection output signal Sa, the intake air amount, which is the integrated value of the intake air flow rate for a predetermined period, for example, every 5 m seconds, is calculated, and from the calculation result, Cylinders 11-16 and 1
The amount of intake air at the end of the intake stroke in each stroke cycle for cylinder The amount is set, and the additional basic fuel injection amount is corrected by a correction amount that is set based on the cooling water temperature and the like represented by the detection output signal Sx to obtain the additional final fuel injection amount. Then, an additional injection drive pulse signal CPA having a pulse width corresponding to the determined additional final fuel injection amount is formed, and it is transmitted to the cylinder 11.
The fuel is sequentially supplied to the fuel injection valves 6 corresponding to the cylinders 11-16 and 17-22 in accordance with the order of ignition timing in the cylinders 11-16 and 17-22.

Each fuel injection valve 6 is kept open for a period corresponding to the pulse width of the injection drive pulse signal CP and the pulse width of the additional injection drive pulse signal CPA to inject fuel intermittently. .

In setting the additional basic fuel injection amount,
As shown in A of FIG. 3 (vertical axis: intake air amount Q, horizontal axis: time t), fuel injection from the fuel injection valve 6 is performed by the injection drive pulse signal CP in each stroke cycle for the cylinder X. From the time to, for example, a time tc after a period TO corresponding to 120 degrees of crank rotation has elapsed and before the end of the suction stroke, a time tb which is a short period T1 before the time tc, and a short period T1 from the time tb. 5 represented by the straight line LQN at each of the previous time points ta
Values Qc, Qb, and Qa of the intake air amount, which are the integrated values of the intake air flow rate every m seconds, are determined.

Then, as in the case of A in FIG. 3, the value Qc
The absolute value of the difference between and the value Qb and the absolute value of the difference between the value Qb and the value Qa are approximately equal (|Qc-Qb|≒|Qb-Qa|
), Therefore, when the engine is in a steady operating state with no sudden changes in the amount of intake air, from the values Qc, Qb, and Qa and the period TA from the time tc to the end time tg of the intake stroke, the end time tg of the intake stroke can be determined. The intake air amount Qg is calculated and predicted. For example, the gradient of change in intake air amount obtained by dividing the difference between the value Qc and the value Qb by the short period T1 is
A is multiplied, and the value Qg of the intake air amount at the end of the intake stroke tg is determined (Qg=TA・(Qc−Qb)
/T1), the amount of intake air at the end of the intake stroke tg is predicted.

In addition, as shown in B of FIG. 3 (vertical axis: intake air amount Q, horizontal axis: time t), the absolute value of the difference between the value Qc and the value Qb and the difference between the value Qb and the value Qa is different from the absolute value of (
|Qc-Qb|≠|Qb-Qa|), therefore, when the engine is in a transient operating state such as an accelerating operating state accompanied by a sharp change in the amount of intake air, from time tc, for example, the crank rotation Period TO corresponding to an angle of 120 degrees
Integration of the intake air flow rate every 5 msec, represented by the straight line LQV, at the time tf before the end of the intake stroke after the elapse of the period TB, which is equal to , and at the time te, which is a short period of time T1 before the time tf. The values Qf and Qe of the intake air amount are determined.

Then, the intake air amount Qg at the intake stroke end time tg is calculated and predicted from the values Qf and Qe and the period TC from the time tf to the intake stroke end time tg. For example, the gradient of change in intake air amount obtained by dividing the difference between the value Qf and the value Qe by the short period T1 is multiplied by the period TC,
The value Qg of the amount of intake air at the end of the intake stroke tg is determined (Qg=TC.(Qf-Qe)/T1), and the amount of intake air at the end of the intake stroke tg is predicted. Note that the length of the period TB corresponds to the engine speed, and is set to become longer as the engine speed increases.

In this way, when the engine is in a steady operating state, the prediction is made based on the intake air amount at a period including time tb and tc, and when the engine is in a transient operating state, , an additional basic fuel injection amount according to the value Qg of the intake air amount at the intake stroke end time tg predicted based on the intake air amount at the time including time te and tf, which is later than the time including time tb and tc. is set.

[0021] In the above, the calculation prediction of the intake air amount value Qg at the end of the intake stroke time tg is based on the intake air amount value Qb when the engine is in a steady operating state.
and Qc are used, and when the engine is in a transient operating state, the intake air amount values Qe and fc are used to calculate the intake stroke. The calculation prediction of the intake air amount value Qg at the end time tg is as follows when the engine is in a steady operating state.
The intake air amount values Qa, Qb and Qc are used, and
When the engine is in a transient operating state, in addition to the intake air amount values Qe and Qf, the 5 m
The value of the intake air amount, which is the integrated value of the intake air flow rate per second, may be used and a quadratic method may be used. In such a case, the value of the intake air amount at the end of the intake stroke tg. Calculation and prediction of Qg can be made more accurately.

The injection drive pulse signal CP and the additional injection drive pulse signal CPA from the control unit 40 are supplied to each fuel injection valve 6 from the cylinders 11 to 16 and 17 to 22 when the engine is in a steady operating state. For each of the cylinders, an injection drive pulse signal CP is sent out at a time point to corresponding to the time point to for the cylinder When the pulse signal CPA is sent out and the engine is in a transient operating condition, the cylinders 11-16 and 17-2
2, the injection drive pulse signal CP is sent out at the time to corresponding to the time to for the cylinder X described above, and the injection drive pulse signal CP is sent at the time tf for the cylinder
An additional injection drive pulse signal CPA is sent out at time tv immediately after the time corresponding to .

That is, for example, for the fuel injection valves 6 corresponding to cylinders 11 to 16 in the first cylinder bank 2, as shown in FIG.
When the detection output signal Sc (A in FIG. 4) obtained from the engine is in a steady operating state and the level is reversed every 60 degrees of crank rotation angle, the injection drive pulse signal C
P and the additional injection drive pulse signal CPA are applied to the cylinder 11.
The fuel injection valve 6 corresponding to the cylinder 15 has the timing shown by the solid line in G in FIG. 4, and the fuel injection valve 6 corresponding to the cylinder 15 has the timing shown in the solid line in B in FIG. The fuel injector 6 corresponding to the cylinder 16 is injected with the timing as shown by the solid line in FIG. Fuel is sequentially supplied to the injection valve 6 at the timing shown by the solid line in E in FIG. 4, and to the fuel injection valve 6 corresponding to the cylinder 14 at the timing shown by the solid line in F in FIG. On the other hand, when the engine is in a transient operating state, the injection drive pulse signal CP is applied to the cylinders 11, 15,
13, 16, 12, and 14, and the additional injection drive pulse signal CPA is supplied to the fuel injection valve 6 corresponding to the cylinder 11 in FIG.
At the timing indicated by the dashed line at G in FIG.
At the timing shown by the dashed line in B of FIG.
At the timing indicated by the dashed line at C in FIG.
At the timing indicated by the dashed line at D in FIG.
At the timing shown by the dashed line at E in FIG.
The signals are sequentially supplied at the timing shown by the dashed line at F in FIG.

The injection drive pulse signal CP and the additional injection drive pulse signal CP for the fuel injection valves 6 corresponding to the cylinders 17 to 22 in the second cylinder bank 3 are
The supply of A is also performed in the same manner as in the case of the fuel injection valves 6 corresponding to the cylinders 11 to 16.

By performing fuel injection control in this manner, when the engine is in a transient operating state,
The prediction of the intake air amount at the end of the intake stroke of each stroke cycle for cylinder Since the amount of intake air is predicted with high accuracy, the amount of additional fuel injection can sufficiently follow changes in the amount of intake air, and as a result, the amount of fuel supplied to the engine can be adjusted to avoid sudden changes in the amount of intake air. can be changed without response delay. On the other hand, when the engine is in a steady operating state, the predicted timing of the intake air amount at the end of the intake stroke of each stroke cycle for cylinder X is set sufficiently before the end of the intake stroke, and the predicted intake air amount is Since fuel is supplied to each cylinder at a supply amount corresponding to the amount of fuel supplied sufficiently before the end of the intake stroke, the fuel is vaporized and atomized well, and the combustibility of the air-fuel mixture is improved.

A control unit 40 that performs the control as described above.
is configured using, for example, a microcomputer, and is an example of a program executed by the microcomputer in such a case to perform fuel supply control that sets the additional fuel supply amount and supplies fuel with the set additional fuel supply amount. will be explained with reference to the flowchart shown in FIG.

In the program shown in the flowchart of FIG. 5, after the start, various detection output signals are taken in at step 50, and then, at step 51, data from time to to time tc in each stroke cycle for cylinder X is taken in. For example, the period TO is set to correspond to a crank rotation angle of 120 degrees. Next, in step 52, the values Qa, Qb, and Qc of the intake air amount at times ta, tb, and tc in each stroke cycle for cylinder X, which are set by setting the period TO in step 51, are determined. , is determined based on the intake air amount Q calculated as an integrated value for every 5 m seconds of the intake air flow rate represented by the detection output signal Sa.

Next, in step 53, based on the intake air amount values Qa, Qb, and Qc obtained in step 52, the absolute value of the difference between the value Qc and the value Qb is determined |Qc−Qb
| and the absolute value of the difference between the value Qb and the value Qa |Qb-Qa| are calculated, and in step 54, the absolute value |Qc-Qb|
and the absolute value |Qb-Qa| are approximately equal (|Qc-Qb|
≒|Qb−Qa|). As a result, if the absolute value |Qc-Qb| and the absolute value |Qb-Qa| are approximately equal, it is assumed that the engine is in a steady operating state, and in step 55, the value of the intake air amount determined in step 52 is determined. From Qc and Qb, the short period T1, and the period TA from time tc in each stroke cycle to the end of the suction stroke tg for cylinder Calculate and predict (Qg=TA・(Qc-Q
b)/T1).

Then, in step 56, an additional basic fuel injection amount is set in accordance with the intake air amount Qg at the intake stroke end point tg calculated and predicted in step 55, and the detection output signal Sx is applied to the additional basic fuel injection amount. The additional final fuel injection amount is set by adding correction based on the correction amount set based on the cooling water temperature etc. Next, step 5
In step 7, an additional injection drive pulse signal CPA having a pulse width corresponding to the additional final fuel injection amount set in step 56 is formed, and is applied to the cylinders 11 to 16 and 17.
The fuel is sequentially delivered to the fuel injection valves 6 corresponding to each of the fuel injection valves 22 to 22 at the timing of time tn, and then the process returns to step 50.

On the other hand, as a result of the determination in step 54, if the difference between the absolute value |Qc-Qb| and the absolute value |Qb-Qa| is different (|Qc-Qb|≠|Qb-Qa|), the engine Assuming that is in a transient operating state such as an accelerated operating state,
In step 58, the period TB from time tc to time tf in each stroke cycle for cylinder
Set equal to . Subsequently, in step 59, the values Qe and Qf of the intake air amount at times te and tf in each stroke cycle for cylinder X, which are set by setting the period TB in step 58, are detected as output signals It is determined based on the intake air amount Q, which is calculated as an integrated value every 5 m seconds of the intake air flow rate represented by Sa, and the process proceeds to step 60.

In step 60, the values Qe and Qf of the intake air amount determined in step 59, the short period T1, and the time tf in each stroke cycle for the cylinder
Calculate and predict the intake air amount Qg at the suction stroke end time tg in each stroke cycle for cylinder X from the period TC from TC to the suction stroke end time tg (Qg
=TC・(Qf−Qe)/T1). Then, in the next step 61, an additional basic fuel injection amount is set according to the intake air amount Qg at the intake stroke end point tg calculated and predicted in step 60, and the detection output signal Sx is set to the additional basic fuel injection amount. The additional final fuel injection amount is set by adding correction based on the correction amount set based on the indicated cooling water temperature, etc. Subsequently, in step 62, an additional injection drive pulse signal CPA having a pulse width corresponding to the additional final fuel injection amount set in step 61 is formed, and is applied to each of the cylinders 11-16 and 17-22. The fuel is sequentially delivered to the fuel injection valves 6 at time tv, and then the process returns to step 50.

[0032]

As is clear from the above description, according to the engine control device according to the present invention, when the combustion state in the cylinders of the engine is controlled according to the operating state of the engine, the engine is in a steady operating state. sometimes,
At a first time before the end of the suction stroke during each stroke cycle for one cylinder in the engine, the suction stroke is terminated based on a variable factor related to the operating state of the engine, e.g., the amount of intake air. A first prediction is made to predict the change factors that are responsible for the operating state of the engine at a time, and when the engine is in a transient operating state, such as an accelerated operating state, during each stroke cycle for one cylinder in the engine. Change factors that affect the operating state of the engine at the end of the intake stroke, based on the changing factors that affect the operating state of the engine at a second time before the end of the intake stroke and later than the first time. A second prediction is made to predict the combustion state in the cylinder, and the combustion state in the cylinder is controlled according to a change factor related to the engine operating state at the end of the intake stroke predicted by the first prediction side or the second prediction. Therefore, the internal combustion state of each cylinder is controlled by controlling the fuel supply amount to each cylinder not only when the engine is in a steady operating state but also when the engine is in a transient operating state such as an accelerating operating state. It is possible to appropriately follow and change the changing factors related to the operating state, such as changes in intake air amount, and to accurately match the amount of fuel supplied to each cylinder with the amount of intake air supplied to each cylinder. be able to. Furthermore, when the engine is in a steady operating state, changing factors related to the engine operating state at the end of the predicted intake stroke, for example, fuel supply to each cylinder with a supply amount according to the intake air amount, Since this is done sufficiently before the end of the intake stroke, the fuel is vaporized and atomized well, and the combustibility of the air-fuel mixture is improved.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram showing an engine control device according to the present invention in accordance with the claims.

FIG. 2 is a schematic configuration diagram showing an example of an engine control device according to the present invention together with an engine to which it is applied.

FIG. 3 is a characteristic diagram used to explain the operation of the example shown in FIG. 2;

FIG. 4 is a characteristic diagram used to explain the operation of the example shown in FIG. 2;

FIG. 5 is a flowchart showing an example of a program executed by a microcomputer when the control unit included in the example shown in FIG. 2 uses the microcomputer.

[Explanation of symbols]

1 Engine body 2 First cylinder bank 3 Second cylinder bank 5 Distributor 6 Fuel injection valve 23 Common intake passage 31 Crank angle sensor 32 Rotation speed sensor 40 Control unit

Claims (2)

[Claims] 1. An operating state detection means for detecting an operating state of an engine, and a state in which the operating state of the engine detected by the operating state detection means is a steady operating state in which state changes are relatively small. an operating state determining means for determining whether the operating state is a transient operating state in which the change is relatively large; and the engine at a first time before the end of the intake stroke during each stroke cycle for one cylinder in the engine. a first prediction of a change factor involved in the operating state of the engine at the end of the intake stroke based on a change factor related to the operating state of the engine, or each stroke for one cylinder in the engine; Operation of the engine at the end of the intake stroke based on changing factors related to the operating state of the engine at a second time before the end of the intake stroke during the cycle and later than the first time. a prediction means that performs a second prediction for predicting change factors related to the state; and when the operating state determining means determines that the operating state of the engine is in the steady operating state, the predicting means performs the second prediction; A first prediction is made, and the in-cylinder combustion state of the engine is controlled according to a change factor related to the operating state of the engine predicted by the first prediction, and the operating state determining means When it is determined that the operating state of the engine is in the transient operating state, the prediction means is caused to perform the second prediction, and changes related to the operating state of the engine predicted by the second prediction are made. An engine control device comprising: combustion state control means for controlling the combustion state in the cylinders of the engine according to factors. 2. An operating state detecting means for detecting an operating state of the engine; and a state in which the operating state of the engine detected by the operating state detecting means is a steady operating state in which state changes are relatively small. an operating state determining means for determining whether the operating state is a transient operating state in which the change is relatively large; and the engine at a first time before the end of the intake stroke during each stroke cycle for one cylinder in the engine. A first prediction that predicts the amount of intake air in the engine at the end of the intake stroke based on the amount of intake air in the engine, or before the end of the intake stroke during each stroke cycle for one cylinder in the engine. and predicting the intake air amount in the engine at the end of the intake stroke based on the intake air amount in the engine at a second time period that is later than the first time period.
and when the operating state determining means determines that the operating state of the engine is the steady operating state, causing the predicting means to perform the first prediction; In addition to setting the fuel supply amount according to the intake air amount in the engine predicted by the prediction,
When the operating state determining means determines that the operating state of the engine is the transient operating state, the predicting means is caused to perform the second prediction, and the engine predicted by the second prediction is a fuel supply amount setting means for setting a fuel supply amount according to an intake air amount in the engine; and a fuel supply means for supplying fuel to the engine using the fuel supply amount set by the fuel supply amount setting means. An engine control device consisting of