JP3328319B2 - Throttle opening control method for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an internal combustion engine (engine).
The present invention relates to a throttle opening control method for adjusting the output of the throttle valve.
That is, it shows how to control the throttle opening in a device generally called an electronic throttle control device.

An electronic throttle control device is a device in which an accelerator and a throttle are connected by a control device constituted by an electronic circuit, and a microcomputer system is generally used as the control device.

The advantage of performing throttle opening control using an electronic throttle control device is that optimal throttle opening control can be performed according to the operating state of the engine. For example, in a lean burn engine, the throttle control can be performed while keeping the fuel efficiency and the combustion state optimal.

[0004] Power characteristics with excellent drivability can be imparted by referring to a vehicle speed signal of an automobile, a shift signal of a transmission, and the like.

[0005] However, even if a slight change in an extremely short time, such as an accelerator operation amount or an engine speed, is applied as a factor of input variation in controlling the throttle opening, if the throttle opening control is performed faithfully, the throttle opening will be reduced. May cause a hunting phenomenon.

Therefore, it is required to establish a throttle opening control method that does not impair the engine response and does not cause the hunting phenomenon.

[0007]

2. Description of the Related Art (1) Configuration of Throttle Control Device FIG. 8 is a block diagram illustrating a configuration example of an electronic throttle control device.

1) Throttle, its adjusting / driving mechanism and sensor The throttle 9 is connected to an actuator 8 for adjusting the opening of the throttle 9, that is, a stepping motor.
The actuator 8 is driven by the actuator driving unit 7 with electric power.

An opening sensor 10 for detecting the opening of the throttle 9 and an idling switch 11 for detecting that the throttle 10 is in an idling state are connected to the throttle 9.

A throttle opening signal corresponding to the opening TA of the throttle 10 is obtained from the opening sensor 10, and a throttle idling signal indicating an idling state TA _SW is obtained from the idling switch 11.

2) Accelerator and Sensor There are connected to the accelerator 1 an operation amount sensor 2 capable of detecting the operation amount and an idling switch 3 for detecting that the accelerator 1 is in an idling state.

The operation amount sensor 2 obtains an accelerator operation amount signal corresponding to the operation amount VPA of the accelerator 1, and the idling switch 3 obtains an accelerator idling signal indicating the idling state VPA _SW .

3) ECU (Electronic Control Unit) The ECU 6 is constituted by the microcomputer system 4 and inputs and outputs signals from its input port and output port.

Incidentally, the microcomputer system 4 of the ECU shown in FIG. 8 is an A / D converter (Analog-To
-Digital Converter) Built-in 1-chip CPU (Central P
(Rocessing Unit) is convenient because an analog input signal can be handled as it is. The input buffer 12 and the output buffer 13 are provided to supplement the input / output drive capability of the microcomputer system 4.

The signals input to the microcomputer system 4 from the input ports include the throttle opening signal (TA), the throttle idling signal (TA _SW ), and the throttle opening signal (TA) described in 1) and 2) above.
Accelerator operation amount signal (VPA), accelerator idling signal (V
PA _SW ). In addition, the engine speed signal (N
E), and the throttle opening is controlled with reference to the engine speed NE.

The microcomputer system 4
Monitors the signals (TA), (TA _SW ), (VPA), (VPA _SW ) (NE), and controls the throttle to a throttle opening optimum for the operating state of the engine. That is, the actuator driving unit 7
Outputs a drive signal S _C to operate the controls on the throttle opening degree TA of interest.

On the other hand, a WDT (Watch Dog Timer) 5 is a watchdog timer for monitoring the microcomputer system 4 for runaway or malfunction, and resets the microcomputer system 4 when runaway or malfunction occurs. To restart.

In FIG. 8, WDC is a signal for the WDT 5 periodically outputted by the microcomputer system 4, and RESET is a reset signal which becomes active when the WDC signal is no longer input.

(2) Operation of throttle control device The throttle control device shown in FIG. 8 is basically a feedback control system.

That is, the accelerator 1 and its operation amount sensor
Accelerator obtained from 2 and idling switch 3
Control signal (VPA), accelerator idling signal (VPA_SW)
Is the control target value, while the throttle 9 and its opening
Slot obtained from the switch 10 and the idling switch 11.
Torque signal (TA), throttle idling signal (T
A _SW) And the engine speed signal (NE)
This is a feedback control system using a feedback signal.

In controlling the feedback control system, the microcomputer system 4 plays a major role in controlling the operation of the control system. That is, the signals (TA) (TA _SW ) (VPA)
(VPA _SW ) (NE) is monitored, and the drive signal is adjusted so that the opening TA of the throttle 9 corresponding to the operation amount VPA of the accelerator 1 is obtained.
This is because S _C is output.

[0022] Then, the actuator driving unit 7 is driven in the driving signal S _C is the actuator 8 to the power drive, as a result, a mechanism in which the opening of the throttle 9 is adjusted in accordance with the driving amount of the actuator 8.

(3) Method of Controlling Throttle Opening In a lean burn engine, the throttle opening is controlled with particular emphasis on the operating state of the engine, that is, the combustion state and fuel efficiency.

FIGS. 9A and 9B are diagrams for explaining the throttle opening calculation map data. FIG. 9A is a map data diagram for obtaining the output torque required of the engine from the accelerator opening and the engine speed. FIG. 4 is a map data diagram for obtaining a target throttle opening degree from an output torque required for an engine and an engine rotation.

That is, the map data shown in FIGS. 9 (a) and 9 (b) are data for controlling the throttle opening while maintaining good fuel economy, combustion state and engine response of the engine. It is stored and held in the memory of the microcomputer system 4 shown in FIG.

Then, the microcomputer system 4
Controls the throttle opening while referring to this map data. That is, a target engine torque TRQ is obtained from the accelerator operation amount VPA and the engine speed NE (see FIG. 9A).
Target throttle opening degree TA from engine speed NE
(See FIG. 9 (b)) to control the throttle opening.

FIG. 10 is a flowchart for explaining the throttle control procedure. FIG. 10 (a) is a flowchart showing a control procedure for inputting an accelerator operation amount, and FIG. 10 (b) is a main control procedure for throttle opening control. It is a flowchart. Note that the control procedure in the figure is realized on software of the microcomputer system 4 shown in FIG.

1) Input procedure of accelerator operation amount The accelerator operation amount VPA is input to the microcomputer system after A / D conversion. The A / D conversion input processing in step S101 is performed by setting a timer in the microcomputer system. While referring, an interrupt process is performed at a predetermined cycle and input.

2) Throttle control procedure That is, after the microcomputer system is initialized in step S201, first, in step S202, the engine speed NE is obtained. This is an operation for calculating the number of rotations from the cycle of the tacho pulse.

Thereafter, the flow shifts to step S203, and a target engine torque TRQ is obtained from the accelerator operation amount VPA and the engine speed NE by referring to the map data of FIG. 9A. Subsequently, in step S204, a target throttle opening TA is obtained from the target engine torque TRQ and the engine speed NE by referring to the map data of FIG. 9B.

Then, in step S205, an actuator control amount for realizing the obtained throttle opening TA is obtained, and in step S206, a drive signal corresponding to the control amount is output. That is, the same throttle opening as the target throttle opening TA is obtained at that time.

[0032]

However, in such a throttle opening control method, the throttle opening may hunt. Hunting is a phenomenon in which the throttle repeatedly opens and closes, and particularly when the throttle opening is small, the hunting amount increases, and the output of the engine is not smoothly adjusted.

That is, as shown in FIG. 9 (a), in the region where the throttle operation amount VPA is small even when the engine speed NE is the same (that is, the region where the engine speed NE is also small), the throttle operation amount VPA is small. Even if it changes slightly, the target engine torque TRQ greatly changes.

As shown in FIG. 9B, even if the engine speed NE is the same and the target engine torque TRQ is the same, the amount of change in the throttle opening is large in a region where the target engine torque TRQ is small. .

That is, in general, in the region where the engine speed NE is small, the throttle opening greatly changes even if the accelerator operation amount is slightly changed.

As a result, even if the accelerator operation amount VPA operated by the engine operator or the vehicle operator has a slight swing which is caused artificially, the throttle opening greatly varies and the hunting phenomenon occurs. It will happen.

A technical object of the present invention is to solve the above-mentioned problems in the conventional throttle opening control method, and to provide a control method which does not cause a hunting phenomenon while controlling the throttle opening according to the operating state of the engine. Is to realize an engine that achieves both low fuel consumption and good engine response.

[0038]

FIGS. 1A and 1B are diagrams for explaining the basic principle-1 of the present invention. FIG. 1A is a diagram for explaining a temporal change of an accelerator operation amount, and FIG. 6 is a flowchart illustrating a procedure to be determined. FIG. 2 is a diagram illustrating the basic principle-2 of the present invention, and is a flowchart illustrating a procedure for obtaining a throttle opening.

According to the present invention, when the accelerator operation amount VPA slightly fluctuates for a very short time Δt, the fluctuation is not directly reflected as a control amount of the throttle opening TA, but is determined at a predetermined rate. The feature is that control is performed so as to reduce and reflect it.

In the present specification and the drawings, the operation with the above-mentioned swing amount reduced is referred to as "nasu". Further, the ratio of reducing the swing amount is “smoothing amount”, the process of reducing the swing amount is “smoothing process”, and the constant defining the smoothing amount is “smoothing constant” K ₁
ＫK _n , K ₁₁ ＫK _1n . (1) The control method that forms the target value of the throttle opening (Fig. 1
And Fig. 9) Accelerator operation amount VPA and engine speed N
A throttle opening degree control method for an internal combustion engine that obtains a target engine torque TRQ from E, obtains a target throttle opening degree TA from the target engine torque TRQ and the engine speed NE, and controls the throttle opening degree. The throttle opening is controlled as described above. That is, the theoretical target throttle opening TA obtained from the target engine torque and the engine speed is smoothed to obtain the target throttle opening to be controlled, and the accelerator operation within a predetermined time Δt is determined. The amount of change DVPA of the amount VPA is obtained, and the smoothing amount when reflecting the theoretical target throttle opening TA on the target throttle opening to be controlled is changed by the magnitude of the change amount DVPA of the accelerator operation amount VPA. This is a throttle opening control method to be performed. (2) The control method when the change in the accelerator operation amount is large (see FIGS. 1 and 9), that is, in the throttle opening control method (1), a predetermined time Δt
When the change amount DVPA of the accelerator operation amount VPA within the range exceeds a predetermined value α, a throttle opening control method for directly reflecting the theoretical target throttle opening as a target throttle opening to be controlled. It is.

(3) Throttle opening degree control method for changing engine speed (see FIGS. 1 and 9) A target engine torque TRQ is obtained from accelerator operation amount VPA and engine speed NE, and the target engine torque is obtained. In a throttle opening control method for an internal combustion engine that controls a throttle opening by obtaining a target throttle opening TA from TRQ and the engine speed NE, the throttle opening is controlled as follows.
That is, the engine speed NE is smoothed, and the target throttle opening degree is determined based on the smoothed engine speed NE.
TA is obtained, the change amount DVPA of the accelerator operation amount VPA within a predetermined time Δt is obtained, and the smoothing amount at the time of smoothing the engine speed NE is calculated by changing the accelerator operation amount VPA. This is a throttle opening control method that is changed according to the magnitude of the amount DVPA. (4) The control method when the change in the accelerator operation amount is large (see FIGS. 2 and 9), that is, in the throttle opening control method (3), the predetermined time Δt
When the change amount DVPA of the accelerator operation amount VPA in the engine exceeds a predetermined value α, the throttle opening control method for directly reflecting the engine speed NE to the target throttle opening TA without smoothing the engine speed NE. It is.

[0042]

(1) Control method for forming target value of throttle opening (see FIGS. 1 and 9) In this throttle opening control method, a predetermined time Δ
When the change amount DVPA of the accelerator operation amount VPA within t is small, the change amount DVPA hardly reflects on the throttle opening. That is, hunting of the throttle opening does not occur due to the swing of the accelerator operation amount VPA. That is, the change amount DVPA of the accelerator operation amount VPA is determined by the throttle opening.
The ratio reflected in TA is small.

However, if the change amount DVPA of the accelerator operation amount VPA within the predetermined time Δt is large, it is considered that the operator who operates the accelerator is intentionally operating the throttle valve. Increase the reflection ratio to the opening degree TA.

As a result, good engine response can be ensured while preventing hunting of the throttle opening.

In the principle diagram of FIG. 1B, the target throttle opening is calculated from the accelerator operation amount VPA _{i at} time t _i .
The principle procedure for finding TA _i is shown. That is, the size by smoothing constants K ₁ ~K _n variation DVPA _i of the accelerator operation amount VPA _i (where, K ₁ ~K _n is an integer) to select (step S1101~ step S1104), then the accelerator The theoretical target throttle opening TA _i is obtained by referring to the map data from the operation amount VPA _i and the engine speed NE _i (step S1105).

Then, at time t_i-1Throttle at the time
Opening TA_i-1And the theoretical target throttle opening TA_iWhen
From the target throttle opening to be controlled by the following equation (1)
Degree TA _iIs calculated (step S1107).

TA _i = (1 / K _i ) TA _i + ｛(K _i -1) / K _i ｝ TA _i -1 (1) That is, the theoretical target throttle The opening TA _i is 1 / K _i
And the throttle opening TA _i-1 at time t _i-1 is reflected by (K _i -1) / K _i . That is, the target throttle opening degree TA _i theoretical, and raw to 1 / K _i. (2) Control method when change in accelerator operation amount is large (see FIGS. 1 and 9) In this throttle opening control method, the accelerator operation amount
The case where the change amount DVPA of the VPA exceeds the predetermined value α is a case where the acceleration operation or the deceleration operation of the engine output or the traveling speed of the vehicle is obvious.

Therefore, in such a case, by reflecting the change amount DVPA of the accelerator operation amount VPA as it is on the throttle opening, the engine response is not impaired.

In the principle diagram of FIG.
Step S for performing the above determination at 06 and performing the smoothing amount calculation
1107 is jumping.

(3) Throttle opening control method for changing engine speed (see FIGS. 1 and 9) In this throttle opening control method, a predetermined time Δ
When the change amount DVPA of the accelerator operation amount VPA within t is small, the change amount of the engine speed NE is equal to the throttle opening TA
Is hardly reflected when asking. That is, even if the engine speed NE fluctuates due to the fluctuation of the accelerator operation amount VPA, the target throttle opening obtained by referring to the map data is obtained.
Hunting does not occur in the TA due to fluctuations in the engine speed NE.

However, if the change amount DVPA of the accelerator operation amount VPA within the predetermined time Δt is large, it is considered that the operator who operates the accelerator is intentionally operating, and therefore, the throttle of the engine speed NE is reduced. Increase the reflection ratio to the opening degree TA.

As a result, good engine response can be ensured while preventing hunting of the throttle opening.

In the principle diagram of FIG._iSmell
Accelerator operation amount VPA_iFrom the target throttle opening TA_i
Is shown. That is, accelerator operation
Production VPA_iDVPA_iConstant depending on the size of
K₁₁~ K_1n(However, K₁₁~ K _1nIs a number from 1 to 0)
(Step S1201 to Step S1204), then the time
t_i-1Engine speed NE at_i-1And time t_iTo
Engine speed NE_iFrom equation (2),
Engine speed NE_i(Step S120
6).

NE _i = K _i NE _i−1 + (1−K _i ) NE _i -------------------------- (2) That is, the engine rotational speed NE _i at time t _i (1
Only −K _i ) is reflected, and the engine speed NE _i−1 at time t _i−1 is reflected by K _i . That is, the practical engine speed NE _i, are smoothed to K _i.

[0055] Thereafter, referring to the map data from the accelerator operation amount VPA _i and the engine speed NE _i, obtaining the target throttle opening degree TA _i (step S1207). (4) Control method when the change in accelerator operation amount is large (see FIGS. 2 and 9) In this throttle opening control method, the accelerator operation amount
The case where the change amount DVPA of the VPA exceeds the predetermined value α is a case where the acceleration operation or the deceleration operation of the engine output or the traveling speed of the vehicle is obvious.

Therefore, in such a case, the change in the engine speed NE is directly reflected in the throttle opening to prevent the engine response from being impaired. In the principle diagram of FIG. 2, the above-described determination is made in step S1205, and step S1206 for performing the smoothing amount calculation is jumped.

[0057]

Next, a practical example of how the throttle opening control method according to the present invention can be embodied will be described with reference to an example.

(1) Configuration The configuration of the throttle control device in this embodiment is the same as the configuration shown in FIG. The microcomputer system 4 stores and holds the map data shown in FIGS. 9 (a) and 9 (b).

The basic procedure for obtaining the target throttle opening TA is the same. That is, the microcomputer system 4 calculates a target engine torque TRQ from the accelerator operation amount VPA and the engine speed NE (see FIG. 9A), and then calculates the target engine torque TRQ and the engine speed NE. Then, a target throttle opening TA is obtained (see FIG. 9A) to control the throttle opening.

However, in order to prevent the hunting phenomenon of the throttle opening from occurring, the target throttle opening TA
Is that an averaging process is performed when obtaining And it can be realized on the software of the microcomputer system 4.

(2) Operation Example-1 FIG. 3 is a flowchart for explaining the main control procedure of the embodiment.

FIGS. 4A and 4B are flow charts for explaining the control procedure of the embodiment. FIG. 4A is a flow chart showing a procedure for measuring the elapsed time by a timer, and FIG. 4B is a flow chart for outputting an actuator drive signal. A flowchart showing
(c) is a flowchart showing a procedure for inputting the accelerator operation amount. Note that (a) to (c) are executed by interrupt processing.

That is, the operation shown in FIG. 4A is a procedure in which the process shifts to step S302 every 4 msec in step S301 to count up the interval counter INT _VPA . Then, the elapsed time is determined by referring to the interval counter INT _VPA during the main control procedure shown in FIG.

Step S501 in FIG. 4 (b) is an operation for varying the throttle opening by outputting an actuator drive signal, and is periodically executed by a timer coincidence interrupt. On the other hand, step S601 in FIG. 4 (c) is a work for inputting the accelerator operation amount VPA to the microcomputer system. An operation for generating an interrupt every time the A / D conversion is completed and inputting it to the microcomputer system. It is.

Next, the main control procedure will be described for each stage with reference to FIG.

1) System Initialization Step That is, in step S401, each part of the microcomputer system and the throttle control device is set to an initial state.

2) Step of finding theoretical target throttle opening: That is, first, in step S402, the engine speed NE is found. This is an operation for calculating the number of rotations from the cycle of the tacho pulse.

Thereafter, the flow shifts to step S403, and a target engine torque TRQ is obtained from the accelerator operation amount VPA and the engine speed NE by referring to the map data of FIG. 9A.

Next, the routine proceeds to step S404, in which the throttle opening TA before one control routine up to that point is set to TAO.
And

Then, in step S405, a target throttle opening TA is determined from the target engine torque TRQ and the engine speed NE by referring to the map data shown in FIG. 9B.

3) Step of Obtaining Change in Accelerator Operation Amount Next, the process proceeds to step S406, where the maximum accelerator operation amount VPA _MAX up to then and the magnitude of accelerator operation amount VPA at that time are compared. Then, the accelerator operation amount at the time
The process moves to step S407 only when the VPA is large,
Substitute VPA for _MAX .

Subsequently, the flow shifts to step S408, where the minimum accelerator operation amount VPA _MIN and the accelerator operation amount VPA at that time are compared. Then, only when the accelerator operation amount VPA at that time is small, step S409
Go to and substitute VPA for VPA _MIN .

Incidentally, Step S406 to Step S40
The processing of No. 9 will be explained with reference to the model on the figure.

FIG. 5 is a model diagram for explaining the swing state and the change state of the accelerator operation amount at the time of the constant speed operation and the acceleration operation. FIG. 5 (a) shows the temporal swing of the accelerator operation amount at the time of the constant speed operation. FIG. 7B is a diagram showing a state, and FIG. 7B is a diagram showing a state of the accelerator operation amount over time during acceleration operation. 5 (a) and 5 (b)
Is different from the scale of the time axis and the scale of the VPA axis in FIG. 5B, the scale of FIG. 5B is large for both the time axis and the VPA axis.

That is, steps S406 to S40
In Fig. 9, the maximum accelerator operation amount VPA _MAX and minimum value VP
_Obtaining A _MIN is shown in Fig. 5 (a) during constant speed operation.
Is equivalent to obtaining the swing amount DVPA as exemplified in
During acceleration operation, this corresponds to obtaining the required acceleration amount DVPA as illustrated in FIG. 5 (b).

4) Step of obtaining the swing amount of the accelerator operation amount within a predetermined time. That is, in step S410, a measurement time for every 100 msec is defined, and every time the interval timer INT _VPA counts 100 msec, the process proceeds to step S411. The difference between the maximum value VPA _MAX and the minimum value VPA _MIN of the accelerator operation amount is determined by the swing amount DVPA.
Asking. However, the interval timer INT _VPA
If it is less than 100 msec, the process proceeds to step S418, and the throttle opening control before the one control routine is continued as it is.

5) Smoothing Constant Determination Step That is, in step S412, the swing amount DV of the accelerator operation amount is determined.
It is determined whether the PA is smaller than a predetermined amount, for example, a numerical value 3, and only when it is smaller, the process proceeds to step S413 to set the smoothing constant K = 8.

However, if it is determined in step S412 that the DVPA is larger than the numerical value 3, the process proceeds to step S414, and it is determined whether the DVPA is smaller than a predetermined amount, for example, a numerical value 5. Only, the process proceeds to step S415, and the smoothing constant K is set to 4. On the other hand, step S414
If it is determined that the DVPA is larger than the numerical value 5, the process proceeds to step S416, where the smoothing constant K is set to 2. Note that these smoothing constants are examples.

Then, in step S417, VPA _MAX and VPA
Respectively substituting the accelerator operation amount VPA at that time point in _MIN, thus initializing the VPA _MAX and VPA _MIN.

6) Step S for calculating the throttle opening
At 418, the throttle opening TA is calculated from the following equation (3).

TA = (1 / K) TA + ｛(K−1) / K｝ TAO (3) where, TA in the first term was obtained in step S405
TA, the TAO in the second term is the TA given in step S404
O.

That is, the larger the swing amount or the change amount DVPA of the accelerator operation amount within a predetermined time (100 msec), the smaller the value of the smoothing constant K becomes. In this case, TA in the first term becomes dominant. On the other hand, the smaller the swing amount or the change amount DVPA of the accelerator operation amount is, the larger the value of the smoothing constant K is, and TAO in the second term becomes dominant.

Therefore, the throttle opening does not greatly change due to the swing of the accelerator operation amount during the constant speed operation. On the other hand, the increase in accelerator operation amount during acceleration operation
This is reflected as an increase in the throttle opening.

Finally, the process proceeds to step S419 to calculate an actuator control amount in order to set the throttle opening to a target value TA. Then, the process returns to step S402, and the above control is repeated.

(3) Operation Example-2 This operation example-2 is an operation example for further improving the engine response during the acceleration operation in the operation example-1. Therefore, the control procedure is realized by making some changes to the control procedures illustrated in FIGS.

FIG. 6 is a flowchart for explaining a control procedure in consideration of an acceleration operation request, (a) is a flowchart showing an accelerator operation amount input procedure, (b) is a flowchart showing a calculation procedure in a throttle opening calculation step, It is.

The accelerator operation amount input procedure uses the procedure of FIG. 6A instead of the procedure of FIG. 4C.

That is, at step S701, the accelerator operation amount VPA before the one conversion routine is set to VPAO, and at step S702
Then, the accelerator operation amount VPA at that time is obtained. In step S703, the absolute value of the difference between VPA and VPAO is determined, and it is determined whether the absolute value is greater than a predetermined constant k. That is, the constant k is the accelerator operation amount
It is a constant to determine that the amount of change in VPA is worthy of acceleration demand.

If it is determined in step S703 that the absolute value of the difference between VPA and VPAO is larger than the constant k, the flow shifts to step S704 to set the flag F _VPA to "1".
However, if it is determined that the absolute value of the difference between VPA and VPAO is smaller than the constant k, the flow shifts to step S705, where the flag F
Set _VPA to "0".

That is, the flag F _VPA = “1” indicates an acceleration operation request, and the flag F _VPA = “0” indicates a constant speed operation state.

Next, the calculation of the throttle opening uses steps S801 to S803 in FIG. 6B instead of steps S418 and S419 in FIG.

That is, in step S801, the flag F _VPA
It is determined whether or not the throttle opening is equal to “1”. If the flag F _VPA is equal to “1”, step S802 is skipped and the throttle opening TA obtained in step S405 is employed as it is, and the throttle 80
3. Calculate the actuator control amount. Therefore, the smoothing process is not performed for the change in the accelerator operation amount.

However, in step S801, the flag F
_{If VPA} = "0", the flow shifts to step S802 to calculate the throttle opening in the same manner as in the operation example-1. That is, a smoothing process is performed to swing the accelerator operation amount.

(4) Operation Example-3 Next, an embodiment will be described in which the hunting phenomenon of the throttle opening is eliminated by performing a smoothing process on the change / oscillation of the engine speed.

FIG. 7 is a flowchart for explaining an example of control for performing a smoothing process for changing or oscillating the engine speed.
(a) is a flowchart showing a main control procedure, (b) is a flowchart showing an accelerator operation amount input procedure, and (c) is a map data diagram for defining a smoothing amount. The map data (c) is stored and held in the memory of the microcomputer system 4 illustrated in FIG.

1) Input procedure of accelerator operation amount The input procedure of FIG. 7B is executed by a timer interrupt every 6 msec.

That is, in step S1001, the accelerator operation amount VPA is A / D converted and input. And step S
The routine proceeds to 1002, where the accelerator operation amount V at one input routine before this point, that is, at a point 6 msec before this point, V
The absolute value of the difference between the accelerator operating amount VPA of PA _M and the point,
That is, the swing amount DLPA of the accelerator operation amount is obtained.

[0098] Incidentally, it is assumed that the accelerator operation amount VPA _M is allowed to store in the flag or the memory of the microcomputer system. That is, step S1003 is it allowed to stored as VPA _M in order to use the accelerator operation amount VPA at that time point in the next input routine.

In step S1004, an arithmetic average of the past n times, for example, ten times, of the accelerator operation amount VPA is obtained, and the average value is adopted as the accelerator operation amount VPA. That is, step S1004 corresponds to a smoothing process of the accelerator operation amount.

2) Throttle control procedure (main control procedure) That is, in step S901, the throttle control device and the microcomputer system are initialized, and then, the throttle 902 calculates the engine speed NE.

In step S903, the smoothing constant K _FIL is obtained from the swing amount DLPA of the accelerator operation amount obtained in the above 1) with reference to the map data illustrated in FIG. 7C.
Incidentally, the smoothing constant K _FIL takes a value between the numerical value 0 and the numerical value 1, and the value decreases as the swing amount DLPA of the accelerator operation amount increases.

Next, in step S904, a smoothing process of the engine speed is performed by the following equation (4 ₎ to obtain a _smoothed engine speed NE _{FIL (i)} .

NE _{FIL (i)} = K _FIL NE _{FIL (i-1)} + (1−K _FIL ) NE _i ------------- (4) NE _{FIL (i- 1)} is a smoothed value of the engine speed before 1 control routine, NE _i is the engine speed at that time.

That is, if the swing amount DLPA of the accelerator operation amount is small, the smoothing constant K _FIL becomes large.
Becomes dominant, and the amount of swing DLPA of the accelerator operation amount
Is larger, the smoothing constant K _FIL becomes smaller.
The second term in (4) becomes dominant. In other words, in the constant-speed operation state where the swing amount DLPA of the accelerator operation amount is small, the ratio of the change in the engine speed is small, and when the acceleration operation swing request is large, the change in the engine speed is small. Is reflected more.

Therefore, if we state the conclusion ahead of time,
The engine speed fluctuates due to the fluctuation of the actuator operation amount, and as a result, the hunting phenomenon of the throttle opening does not occur.

Subsequently, when the process proceeds to step S905, the expression
Engine speed NE _{FIL ( i)} obtained in (4) and step S1004
The target throttle opening degree TA is obtained from the accelerator device amount VPA obtained in the above. Note that the procedure for obtaining the throttle opening degree TA is obtained by referring to the map data shown in FIGS.

Then, an actuator control amount is obtained in step S906, and an actuator drive signal is output in step S907. Thereafter, the process returns to step S902, and the above control is repeatedly executed.

(5) Smoothing processing As described in the above-mentioned operation example, the smoothing processing is a point in the present invention, and the expressions (1) to (4) are the same as those of the smoothing processing.
These are two calculation examples. Therefore, it is possible to perform an averaging process other than such an arithmetic expression.

If the smoothing process is described using a general concept, it is a concept similar to filter processing. However, on the other hand, general filter processing uses only frequency as an input variable. On the other hand, the smoothing process of the present invention targets the amount of fluctuation (fluctuation) of the accelerator operation amount and the amount of fluctuation (fluctuation) of the engine speed within a predetermined time. It means that the frequency is treated as an input variable. Here, the superiority of the annealing process exists.

[0110]

As described above, according to the method for controlling the throttle opening of the engine according to the present invention, the phenomenon that the throttle opening is largely hunted by a slight swing of the accelerator operation amount does not occur.

Accordingly, even when the throttle opening is controlled in accordance with the operating state of the engine, the throttle opening can be controlled while achieving both low fuel consumption and good engine response.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams illustrating a basic principle-1 of the present invention, in which FIG. 1A is a diagram illustrating a temporal change of an accelerator operation amount, and FIG. 1B is a flowchart illustrating a procedure for obtaining a throttle opening. .

FIG. 2 is a view for explaining a basic principle-2 of the present invention, and is a flowchart for explaining a procedure for obtaining a throttle opening;

FIG. 3 is a flowchart illustrating a main control procedure (operation example-1) of the embodiment.

FIG. 4 is a flowchart for explaining a control procedure (operation example-1) of the embodiment, in which (a) is a flowchart showing a procedure for measuring an elapsed time by a timer, and (b) is a flowchart for outputting an actuator drive signal. Flowchart showing the procedure of
(c) is a flowchart showing a procedure for inputting the accelerator operation amount.

FIG. 5 is a model diagram illustrating a swing state and a change state of an accelerator operation amount during a constant speed operation and an acceleration operation,
(a) is a diagram showing a temporal swing state of an accelerator operation amount during a constant speed operation, and (b) is a diagram showing a time change state of an accelerator operation amount during an acceleration operation. It should be noted that the scale of the time axis and the scale of the VPA axis in FIGS.
The scale of (b) is large for both the time axis and the VPA axis.

FIG. 6 is a control procedure considering an acceleration operation request (operation example—
2A is a flowchart illustrating an accelerator operation amount input procedure, and FIG. 2B is a flowchart illustrating a calculation procedure of a throttle opening calculation step.

FIG. 7 is a flowchart illustrating a control example of performing a smoothing process for changing / oscillating the engine speed, where (a) is a flowchart illustrating a main control procedure, (b) is a flowchart illustrating an accelerator operation amount input procedure, (c) is a map data diagram that defines the amount of smoothing.

FIG. 8 is a block diagram illustrating a configuration example of an electronic throttle control device.

FIGS. 9A and 9B are diagrams for explaining throttle opening calculation map data. FIG. 9A is a map data diagram for obtaining an output torque required of an engine from an accelerator opening and an engine speed, and FIG. FIG. 9 is a map data diagram for obtaining a target throttle opening degree from a required output torque and engine rotation.

FIG. 10 is a flowchart for explaining a conventional example of a throttle control procedure, in which (a) is a flowchart showing a control procedure for inputting an accelerator operation amount, and (b) is a main control procedure of throttle opening degree control. It is a flowchart.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Accelerator 2 Accelerator operation amount sensor 3 Accelerator idling switch 4 Microcomputer system (CPU: Central Processing Unit) as a control unit 5 WDT (Watch Dog Timer) 6 Throttle ECU (Electronic Co)
ntrol Unit) 7 Actuator drive unit 8 Actuator 9 Throttle 10 Throttle opening sensor 11 Throttle idling switch 12 Input buffer 13 Output buffer VPA Accelerator operation amount (accelerator operation amount signal) VPA _SW Accelerator idling (accelerator idling signal) TA Throttle opening Degree (throttle opening signal) TA _SW Throttle idling (throttle idling signal) NE Engine speed S _C Actuator drive signal output by ECU WDC Periodic pulse signal output by microcomputer system and monitored by WDT RESET Reset output by WDT signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 45/00 330 F02D 45/00 330

Claims (4)

(57) [Claims] 1. A target engine torque is obtained from an accelerator operation amount (VPA) and an engine speed, and a target throttle opening (TA) is obtained from the target engine torque and the engine speed to obtain a throttle opening. In the method for controlling the throttle opening of an internal combustion engine to be controlled, a logic determined from the target engine torque and the engine speed is used.
The theoretical target throttle opening (TA) is smoothed and controlled.
The target throttle opening to be obtained is obtained, the change amount (DVPA) of the accelerator operation amount (VPA) within a predetermined time (Δt) determined in advance, and the theoretical target throttle opening (TA) is controlled. Changing the smoothing amount to be reflected in the target throttle opening according to the magnitude of the change amount (DVPA) of the accelerator operation amount (VPA). Opening control method. 2. The throttle opening control method for an internal combustion engine according to claim 1, wherein the accelerator operation amount within a predetermined time (Δt) is determined.
When the change amount (DVPA) of (VPA) exceeds a predetermined value (α), the theoretical target throttle opening is controlled.
It is directly be reflected as Rubeki target throttle opening, the throttle opening degree control method in an internal combustion engine according to claim. 3. Accelerator operation amount (VPA) and engine speed
(NE) to obtain a target engine torque, and obtain a target throttle opening (TA) from the target engine torque and the engine speed (NE) to control the throttle opening. In the method, the engine speed (NE) is smoothed, and a target throttle opening (T) is calculated based on the smoothed engine speed (NE).
A), and the accelerator operation amount within a predetermined time (Δt) determined in advance.
The amount of change (VPA) (DVPA) look, the engine rotational speed (NE)
The smoothing amount during the smoothing process is determined by the accelerator operation amount.
A throttle opening degree control method for an internal combustion engine, wherein the throttle opening degree is changed according to a magnitude of a change amount (DVPA) of the (VPA). 4. The throttle opening control method for an internal combustion engine according to claim 3, wherein the accelerator operation amount within a predetermined time (Δt) is determined.
The amount of change (VPA) (DVPA) is, if it exceeds predetermined a predetermined value (alpha), treating moderation engine speed (NE)
Throttle opening control method for an internal combustion engine without directly reflected in the target throttle opening (TA), characterized by.