JPH1047118A - Control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rationalize fuel injection rate control on the basis of a throttle opening information by arranging a throttle opening predicting means for inputting a predicting value on the basis of a target throttle opening as a throttle opening information inputted to a fuel injection rate control means. SOLUTION: In a control unit 10, the signal of an acceleration sensor 11 is read in, an acceleration operating rate is detected, a table which is memorized beforehand is referred from its acceleration opening rate, and a target throttle opening is set in a nearly proportional relation. The opening is read in as the predicting value of a previous throttle opening, and the change rate of the throttle opening is calculated by the difference between the previous value and a present value. Predicting control is carried out for a time when various kinds of correction rate is calculated on the basis of a throttle opening information, by using a target throttle opening. It is thus possible to rationalize fuel injection rate control on the basis of the throttle opening information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an engine control device.

[0002]

2. Description of the Related Art In recent years, instead of a mechanical throttle valve linked to an accelerator pedal by a wire, a command signal from a control unit based on an accelerator operation amount (accelerator pedal depression amount) detected by an accelerator sensor and the like is transmitted via a motor. Electronically controlled throttle valves with controlled opening have been developed.

On the other hand, in the fuel injection amount control, the fuel injection amount is adjusted by various corrections such as air flow meter response delay correction, cylinder intake air amount prediction, and wall flow correction in order to correct the air-fuel ratio deviation at the time of transition. It is carried out. For the various corrections of the fuel injection amount at the time of the above-mentioned transition, it is important to accurately predict the throttle opening information, in particular, the amount of change in the throttle opening. For this reason, conventionally, a throttle sensor is attached to a throttle valve to detect an actual throttle opening, and this is used.

[0004]

However, in order to perform various corrections of the fuel injection amount at the time of transition based on the throttle opening information, the actual throttle opening is detected based on a signal from a throttle sensor. In the case where the amount of change is calculated and various correction amounts are calculated based on the amount of change, the accuracy of prediction (or correction) is limited by the calculation time, and it is currently impossible to correct the air-fuel ratio deviation. Was.

In view of such circumstances, the present invention is based on the premise that an electronically controlled throttle valve is employed, and aims to optimize fuel injection amount control based on throttle opening information by utilizing its characteristics. And

[0006]

Therefore, in the invention according to claim 1, as shown in FIG. 1, an accelerator operation amount detecting means for detecting an accelerator operation amount, and a target based on the detected accelerator operation amount. A target throttle opening setting means for setting a throttle opening, and a throttle valve driving means for driving an electronically controlled throttle valve so as to attain the set target throttle opening. In a control device for an engine including a fuel injection amount control means for controlling a fuel injection amount by a fuel injection valve to a fuel injection amount control means, a predicted value based on the target throttle opening degree is used as throttle opening degree information input to the fuel injection amount control means. A throttle opening predicting means for inputting is provided.

That is, by using a predicted value based on a target throttle opening (control command value) instead of a detected value of the actual throttle opening as the throttle opening information, various correction amounts are obtained based on the throttle opening information. Is calculated as much as possible, and predictive control (preemption correction) is performed as much as possible to improve control accuracy. As a result, an air-fuel ratio error can be reduced, emission can be reduced, and drivability can be improved.

[0008] In the invention according to claim 2, the fuel injection amount control means is a means for controlling the fuel injection amount at the time of transition using the change amount of the throttle opening, and the fuel injection amount control means includes: The method is characterized in that a change amount of the predicted value is used. As described above, a particularly remarkable effect can be obtained by using the control of the fuel injection amount during the transition.

The invention according to claim 3 is characterized in that the throttle opening predicting means sets the target throttle opening as a predicted value of the throttle opening. By using the target throttle opening (control command value) as it is, it can be easily implemented. The invention according to claim 4 is characterized in that the throttle opening predicting means sets a value obtained by delaying the target throttle opening as a predicted value of the throttle opening.

The actual throttle opening is accurately predicted without detection delay by using the target throttle opening (control command value) as described above, for example, by delaying the operation delay of the actuator of the electronically controlled throttle valve. it can. In the invention according to claim 5, between the target throttle opening setting means and the throttle valve driving means (the position of the dotted frame in FIG. 1).
And delay processing means for delay-processing and transmitting the target throttle opening.

That is, for fuel injection amount control, predictive control is performed using the target throttle opening, while for throttle opening control, the target throttle opening after delay processing is used to calculate the calculation delay of fuel injection amount control. By delaying the air amount control by the amount, the phases of the air amount control and the fuel injection amount control are matched to further reduce the air-fuel ratio error. Claim 6
According to the invention, the throttle opening information to be input to the fuel injection amount control means is input to the fuel injection amount control means instead of the throttle opening prediction means for inputting a predicted value based on the target throttle opening. A throttle opening predicting means for inputting a predicted value based on the accelerator operation amount as the throttle opening information is provided (see a dotted line in FIG. 1).

In this case, instead of the prediction using the target throttle opening, the prediction is performed using the accelerator operation amount.
Almost the same operation can be obtained.

[0013]

Embodiments of the present invention will be described below. FIG. 2 shows an embodiment of the system configuration. An electronically controlled throttle valve 3 is provided in an intake passage 2 of the engine 1 to control an intake air flow rate.

The electronically controlled throttle valve 3 is driven by a motor 4 without being mechanically connected to an accelerator pedal. The motor 4 is operated by a command signal from the control unit 10. Each cylinder of the engine 1 is directly exposed to an intake manifold / branch portion, an intake port, or a combustion chamber.
An electromagnetic fuel injection valve 5 is provided. These fuel injection valves 5 are energized and opened by a drive pulse signal output at a predetermined timing in synchronization with engine rotation from the control unit 10, and inject fuel adjusted to a predetermined pressure. Therefore, the fuel injection amount is controlled by the pulse width of the drive pulse signal.

Each cylinder of the engine 1 is also provided with an ignition unit 6, and these ignition units 6 perform an ignition operation in response to an ignition signal from a control unit 10. In order to control the electronically controlled throttle valve 3, the fuel injection valve 5, and the ignition unit 6, the control unit 10 includes an accelerator sensor 11 for detecting an accelerator operation amount (accelerator pedal depression amount) Ac, and a rotation for detecting an engine speed Ne. Detection signals are input from a number sensor (crank angle sensor) 12, an air flow meter 13 for detecting an intake air flow rate Qa, a water temperature sensor 14 for detecting a cooling water temperature Tw, a throttle sensor 15 for detecting a throttle opening, and the like. .

Here, the control unit 10
As a throttle opening control, as shown in a flowchart of FIG. 3 described later, a target throttle opening tTVO is determined based on an accelerator operation amount Ac, and the motor 4 is controlled by a command signal corresponding to the target throttle opening tTVO.
To control the electronically controlled throttle valve 3 so that the target throttle valve opening degree tTVO is achieved.

The control unit 10 determines the basic fuel injection amount Tp based on the intake air flow rate Qa and the engine speed Ne as shown in the flowchart of FIG. Based on this, the final fuel injection amount Ti is determined, and a drive pulse signal having a pulse width corresponding to Ti is output to the fuel injection valve 5 of each cylinder at a predetermined timing synchronized with the engine rotation, and Control the injection volume.

The control unit 10 sets and controls the optimum ignition timing ADV as the ignition timing control by referring to a map from the engine speed Ne and the basic fuel injection amount (load) Tp. Next, the throttle opening control will be described in detail with reference to the flowchart of FIG. This flow is executed every predetermined time.

In step 1 (denoted by S1 in the figure, the same applies hereinafter), the signal of the accelerator sensor 11 is read to detect the accelerator operation amount Ac. This part corresponds to the accelerator operation amount detecting means. In step 2, the target throttle opening tTVO is set in a substantially proportional relationship from the accelerator operation amount Ac with reference to a table stored in advance. This portion corresponds to target throttle opening setting means.

In step 3, the target throttle opening tT
The motor 4 is driven by a command signal corresponding to VO, and the electronically controlled throttle valve 3 is controlled so as to reach the target throttle opening tTVO. This part corresponds to the throttle valve driving means. When controlling the electronically controlled throttle valve 3 so as to reach the target throttle opening tTVO, the throttle sensor
The feedback control is carried out while detecting the actual throttle opening by means of 15.

Next, the fuel injection amount control will be described in detail with reference to the flowchart of FIG. This flow corresponds to the fuel injection amount control means, and is executed every predetermined time or every predetermined rotation. In step 11, the intake air flow rate Qa is detected based on a signal from the air flow meter 13.

In step 12, the change amount Δ of the throttle opening which is predicted and calculated according to the flowchart of FIG.
Read TVO. Then, a transient correction coefficient KQac = f (ΔTVO) for the intake air flow rate Qa is obtained by referring to a table based on the result. In step 13,
The intake air flow rate Qa is corrected by the transient correction coefficient KQac as in the following equation, and the corrected intake air flow rate Qac is obtained.

Qac = Qa * (1 + KQac) In step 14, the basic fuel injection amount Tp is calculated from the corrected intake air flow rate Qac and the engine speed Ne detected by the speed sensor 12 by the following equation. Tp = K * Qacc / Ne (where K is a constant) In step 15, the change amount .DELTA.TVO of the throttle opening which is predicted and calculated according to the flowchart of FIG. Then, the transient correction coefficient Kac = g for the basic fuel injection amount Tp is referred to by referring to a table based on this.
(ΔTVO) is obtained.

In step 16, various correction coefficients COEF including a water temperature correction coefficient Ktw based on the cooling water temperature Tw detected by the water temperature sensor 14 are obtained in addition to the transient correction coefficient Kac, as in the following equation. COEF = 1 + Kac + Ktw +... In step 17, the basic fuel injection amount Tp is corrected by various correction coefficients COEF as in the following equation to calculate the final fuel injection amount Ti.

Ti = Tp * COEF In step 18, the calculated fuel injection amount Ti is set in a predetermined register. When the fuel injection amount Ti is set, a drive pulse signal having a pulse width corresponding to Ti is output to the fuel injection valve 5 of the injection cylinder at a predetermined timing synchronized with the engine rotation, and fuel injection is performed. .

Next, prediction calculation of throttle opening information (ΔTVO) used for fuel injection amount control will be described in detail with reference to the flowchart of FIG. This flow corresponds to a throttle opening degree estimating means and is executed at predetermined time intervals. In step 21, the target throttle opening tTVO is read, and the target throttle opening tTVO is read as the predicted throttle opening TVO = tTVO.
And

In step 22, the difference ΔTVO = TVO−TVOold of the throttle opening is calculated by taking the difference from the previous predicted value TVOold of the throttle opening. As described above, in order to obtain the throttle opening information, the target throttle opening tTV is used instead of the actual throttle opening detection value.
By using O, prediction control (preemption correction) can be performed for a time corresponding to the time for calculating various correction amounts based on the throttle opening information, thereby improving control accuracy.

Next, a second embodiment will be described. FIG.
FIG. 6 is a flowchart of the prediction calculation of the throttle opening information (ΔTVO) instead of FIG. 5 and is executed together with the flowcharts of FIGS. 3 and 4. In step 21, the target throttle opening tTVO is read. In step 22, delay processing of the target throttle opening tTVO is performed. Specifically, the target throttle opening tTVO is stored in a time series, and the value before a predetermined number of times is stored in the target throttle opening tTV after the delay processing.
O '.

In step 23, the target throttle opening degree tTVO 'after the delay processing is replaced with the predicted throttle opening degree TV value.
It is assumed that O = tTVO ′. In step 24, the difference ΔTVO = TVO−TVOold of the throttle opening is calculated by taking the difference from the previous predicted value TVOold of the throttle opening. In this way, the target throttle opening tTVO is delayed by the operation delay of the actuator of the electronically controlled throttle valve 3, and the target throttle opening tTVO 'after the delay processing is used. Can be more accurately predicted.

Next, a third embodiment will be described. FIG.
Is a flowchart of the throttle opening control instead of FIG. 3, and is executed together with the flowcharts of FIG. 4 and FIG. In step 1, the signal of the accelerator sensor 11 is read to detect the accelerator operation amount Ac. This part corresponds to the accelerator operation amount detecting means.

In step 2, the target throttle opening tTVO is set in a substantially proportional relationship from the accelerator operation amount Ac with reference to a table stored in advance. This portion corresponds to target throttle opening setting means. In step 3, delay processing of the target throttle opening tTVO is performed. Specifically, the target throttle opening tTVO is stored in time series, and a value before a predetermined number of times is set as the target throttle opening tTVO 'after the delay processing. This part corresponds to delay processing means.

In step 4, the motor 4 is controlled by a command signal corresponding to the target throttle opening tTVO 'after the delay processing.
To control the electronically controlled throttle valve 3 so that the target throttle opening degree tTVO 'is achieved. This part corresponds to the throttle valve driving means. As described above, the prediction control is performed using the target throttle opening tTVO for the fuel injection amount control, and the calculation of the fuel injection amount control is performed using the target throttle opening tTVO ′ after the delay processing for the throttle opening control. By delaying the air flow control by the delay,
The phases of the air amount control and the fuel injection amount control can be matched.

In the above description, the prediction is basically made using the target throttle opening tTVO. However, even if the prediction is made using the accelerator operation amount Ac, almost the same operation can be obtained. That is, in step 21 of FIG. 5, the target throttle opening tTV
O is read, and is used as a predicted value of the throttle opening TVO =
Instead of tTVO, the accelerator operation amount Ac may be read, and this may be used as the predicted value TVO = Ac of the throttle opening. However, it is necessary to adjust the unit. Also, in steps 21 to 23 in FIG.
Can be implemented.

Further, as the fuel injection amount control at the time of transition, when the change amount ΔTVO of the throttle opening is equal to or more than a predetermined value,
Although there is an interrupt injection performed without waiting for a normal injection timing synchronized with the engine rotation, it is needless to say that the present invention can be applied to this.

[0035]

As described above, according to the first aspect of the present invention, the predicted value based on the target throttle opening is used as the throttle opening information instead of the actual throttle opening detected value. In addition, control accuracy can be improved by performing predictive control (preemption correction) as much as possible, whereby an effect that an air-fuel ratio error can be reduced, emission can be reduced, and drivability can be improved can be obtained.

According to the second aspect of the present invention, a particularly remarkable effect can be obtained by using the present invention for controlling the fuel injection amount during the transition. According to the third aspect of the present invention, the operation can be easily performed by using the target throttle opening as it is. According to the fourth aspect of the present invention, the actual throttle opening can be accurately predicted without detection delay by using the target throttle opening which is delayed.

According to the fifth aspect of the invention, the target throttle opening is used for the fuel injection amount control, and the target throttle opening which is delayed is used for the throttle opening control. The air-fuel ratio error can be further reduced by matching the phase with the injection amount control. According to the invention of claim 6, substantially the same effect can be obtained by making prediction using the accelerator operation amount instead of the target throttle opening.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart of throttle opening control.

FIG. 4 is a flowchart of fuel injection amount control.

FIG. 5 is a flowchart of a throttle opening information prediction calculation;

FIG. 6 is a flowchart of a throttle opening information prediction calculation according to the second embodiment;

FIG. 7 is a flowchart of throttle opening control according to a third embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Intake passage 3 Electric throttle valve 4 Motor 5 Fuel injection valve 10 Control unit 11 Accelerator sensor 12 Speed sensor 13 Air flow meter

Claims (6)

[Claims] An accelerator operation amount detecting means for detecting an accelerator operation amount; a target throttle opening setting means for setting a target throttle opening based on the detected accelerator operation amount; Control means for controlling the amount of fuel injection by the fuel injection valve to the engine using at least the throttle opening information. The engine control device according to claim 1, further comprising: a throttle opening prediction unit that inputs a predicted value based on the target throttle opening as the throttle opening information input to the fuel injection amount control unit. 2. The fuel injection amount control means for controlling a transient fuel injection amount using a change amount of a throttle opening, wherein the change amount of the predicted value is used as the change amount of the throttle opening. 2. The method according to claim 1, wherein
An engine control device according to any one of the preceding claims. 3. The engine control device according to claim 1, wherein the throttle opening predicting means uses the target throttle opening as a predicted value of the throttle opening. 4. The engine according to claim 1, wherein said throttle opening degree predicting means calculates a delay value of the target throttle opening degree as a predicted value of the throttle opening degree. Control device. 5. A delay processing means provided between said target throttle opening setting means and said throttle valve driving means for delay processing and transmitting said target throttle opening. An engine control device according to claim 3. 6. The throttle opening information input to the fuel injection amount control means is input to the fuel injection amount control means instead of the throttle opening degree prediction means for inputting a predicted value based on the target throttle opening degree. The engine control device according to any one of claims 1 to 5, further comprising a throttle opening degree predicting unit that inputs a predicted value based on the accelerator operation amount as the throttle opening degree information.