JPH1136896A - Electronic throttle controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more exactly learn the fully closed position of a throttle valve. SOLUTION: The fully closed position of a throttle valve 14 is learned before starting an engine. In controlling the throttle valve 14 after learning, when the throttle valve 14 is in a sate pushing a stopper, the state is detected based on an overcurrent carried to a motor 15. The learned fully closed position is corrected to the opening of the throttle valve detected by a throttle position sensor 13 to adjust the fully closed position. For every repeat of the pushing state by the throttle valve 14, a compensation degree Δ is added to the fully closed position to successively adjust the fully closed position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, this type of apparatus is disclosed in
Japanese Patent Application Laid-Open No. 41944/1997 discloses an "internal combustion engine output control device". Here, the opening degree of the throttle valve (throttle valve) is adjusted by a motor. When the internal combustion engine is started, the throttle valve is temporarily moved to a fully closed position and a fully open position, and these positions are learned and confirmed. This allows accurate control of the throttle valve.

On the other hand, as another method of learning the fully closed position of the throttle valve, a throttle valve defined by a spring when the throttle valve is not driven by a motor, for example, when the throttle valve is not driven by a motor. The initial position of the throttle valve is detected, a position rotated by a predetermined angle from the initial position is obtained as a fully closed position of the throttle valve, and this is learned.

[0004]

However, when the mechanically determined initial position of the throttle valve is detected and the fully closed position of the throttle valve is learned based on the detected initial position, an error occurs in the learned fully closed position. Tends to occur. For example, a detection error of a sensor for detecting an initial position of a throttle valve, a mechanical error and an electric error due to a temperature change, or an error in a fully closed position learned due to the accumulation of these errors. Sometimes.

If the throttle valve fully learned position is erroneously learned as described above, the motor tends to move the throttle valve closer to the closed side than the actual fully closed position in controlling the drive of the throttle valve. At this time, at this time, the throttle valve hits the stopper, and even after hitting here, the throttle valve tries to move further. For this reason, there has been a problem that various inconveniences such as engine stop due to poor intake air and mechanical distortion around the throttle valve are caused.

Accordingly, the present invention is to solve such a conventional problem, and to provide an electronic throttle control device for an internal combustion engine capable of learning a fully closed position of a throttle valve more accurately. With the goal.

[0007]

In order to solve the above-mentioned problems, the present invention comprises a throttle sensor for detecting an opening degree of a throttle valve, learns a fully closed position of the throttle valve, and detects a position of the throttle valve. An electronic throttle control device for an internal combustion engine that controls the drive of a throttle valve by a motor based on the opening degree of the throttle valve and the fully closed position of the throttle valve obtained by the learning, determines whether the motor is in a locked state. Detecting means for detecting, and learning means for updating, when the detecting means detects that the motor is in a locked state, the opening degree of the throttle valve detected by the throttle sensor at this time as a fully closed position of the throttle valve. And

According to such a configuration, when the motor driving the throttle valve is in the locked state, the opening of the throttle valve detected at this time is set as the fully closed position of the throttle valve. When the throttle valve reaches the fully closed position and hits the stopper, and the throttle valve is about to push the stopper even after hitting it, the motor is locked. If the degree is set as the fully closed position of the throttle valve, an erroneous fully closed position can be corrected and an accurate fully closed position can be learned again.

When the detection means detects that the motor is in the locked state again, the learning means corrects the detected opening degree of the throttle valve by a predetermined compensation amount to make the fully closed state. Update as position.

When an excessive force is applied to the throttle valve and the support mechanism of the throttle valve while the motor is in a locked state, these may be distorted due to insufficient strength. Even if the opening of the throttle valve is set as the fully closed position of the throttle valve, it is not possible to learn an accurate fully closed position. Therefore, when the motor is locked again,
The opening detected at this time is corrected with a predetermined compensation amount in consideration of the distortion of the throttle valve and the support mechanism of the throttle valve, and is set as the throttle valve fully closed position. Thereby, the fully closed position can be learned again more accurately.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the electronic throttle control device of the present invention. In the figure,
The throttle control device 11 controls a double accelerator position sensor 12, a double throttle position sensor 13, a motor 15 for driving a throttle valve 14, and connection and disconnection between the throttle valve 14 and the motor 15. And an electronic control unit (ECU) 17.

The accelerator position sensor 12 includes a main sensor 12-1 and a sub sensor 12-2. Main sensor 1
The 2-1 and the sub-sensor 12-2 detect the accelerator position according to the depression amount of the accelerator pedal 21, and output respective detection signals indicating the accelerator position to the ECU 17.

The throttle position sensor 13 includes a main sensor 13-1 and a sub sensor 13-2. The main sensor 13-1 and the sub sensor 13-2 are connected to the throttle valve 1
4 and outputs respective detection signals indicating the actual opening of the throttle valve 14 to the ECU 17.

The ECU 17 calculates a target opening of the throttle valve 14 based on each detection signal output from the accelerator position sensor 12. Further, the ECU 17 controls the rotation of the motor 15 based on each detection signal output from the throttle position sensor 13 so that the actual opening of the throttle valve 14 approaches the target opening.

During normal running, the ECU 17 turns on the switch 25 to energize the electromagnetic clutch 16 and connects the throttle valve 14 and the motor 15 via the electromagnetic clutch 16.

In such a configuration, immediately before the start of the engine, the mechanically determined initial position of the throttle valve 14 is detected, and the fully closed position of the throttle valve is learned based on this initial position. This processing will be described with reference to the flowchart of FIG. 2 and the timing chart of FIG.

First, at time t ₀ , when the ignition switch 24 is turned on (step 101, Yes), E
The CU 17 determines whether the learning completion flag is turned on (Step 102). At this time, immediately after the ignition switch 24 is turned on, the learning completion flag is off in the initial state. Therefore, the ECU
In step 17, the learning completion flag is determined to be off (step 102, No).

Next, the ECU 17 increments the count value T of the learning counter built in the ECU 17 by one (step 1).
03), it determines whether exceeds this count value T is determined whether exceeds a value T ₁ that is determined in advance (step 104), the value T ₀ defined subsequently count T in advance ( Step 105). At this time, immediately after the counting of the count value T is started, the ECU 17 determines that the count value T
_0, it is determined that T ₁ is less than (step 104, No, step 105, No), the process returns to step 101 to repeat the processes of the steps 101 to 105.

In this manner, the processing of steps 101 to 105 is repeated, and while the count value T is incremented each time, the processing shown in FIG.
When the count value T exceeds the value T ₀ after the time point t ₁ shown in (step 105, Yes), the ECU 17 determines whether the accelerator opening is smaller than the predetermined threshold value based on the detection output of the accelerator position sensor 12. It is determined whether or not there is (step 1
06).

If the opening / closing of the throttle valve 14 relies solely on the drive by the motor 15, the throttle valve 14 cannot be opened / closed when the motor 15 or the electromagnetic clutch 16 or the like fails, so that the accelerator pedal 21 can be sufficiently released. When depressed, the throttle valve 14 is opened by mechanical interlocking. In this state, since the initial position of the throttle valve 14 cannot be detected, the accelerator pedal 21 is depressed, and if the accelerator opening is equal to or larger than the threshold (step 106, N
o), and return to step 101;

If the accelerator opening is smaller than the threshold value (step 106, Yes), the ECU 17 determines whether or not the throttle position sensor 13 is normal based on the detection output of the throttle position sensor 13. (Step 1
07), if the throttle position sensor 13 is not normal (step 107, No), the process returns to step 101.

If the throttle position sensor 13 is normal (step 107, Yes), the ECU 17 stores the opening of the throttle valve 14 detected by the throttle position sensor 13 as an initial position (step 108). Thereafter, the ECU 17 determines that the count value T is equal to the value T _1.
Is determined (step 109), and the count value T
There does not reach the value T _1, the flow returns to step 101.

The processing of steps 101 to 109 is repeated, each time the count value T is incremented, and the throttle valve 14 detected by the throttle position sensor 13 is used.
Is set as the initial position.

Next, at time t ₂ shown in FIG. 3, the count value T reaches the value T ₁ (step 109, Yes), ECU 17
Sets the learning completion flag to ON (step 11
0) Based on the last detected initial position of the throttle valve 14, a position rotated by a predetermined angle from this initial position is determined as the fully closed position of the throttle valve 14, and this is learned (step 111). .

When the accelerator pedal 21 is depressed and the accelerator opening is equal to or larger than a predetermined value (step 106, No), or when the throttle position sensor 13 is not normal (step 107, N
o), the count value T exceeds the value T ₁ (step 104, Ye
s), the ECU 17 adopts the fully closed position of the throttle valve 14 learned and stored at the time of the previous process (previous start) instead of the fully closed position that could have been learned this time (step 112). .

Thereafter, at a time point t ₃ shown in FIG. 3, when a throttle relay (not shown) is turned on, electric power from a power supply (not shown) is supplied to the motor 15.
Once t ₄ when shown in, the electromagnetic clutch 16 is turned on, the throttle control by the motor 15 from the time t ₅ shown in FIG. 3 is started.

This throttle control is a control for opening and closing the throttle valve 14, and is performed according to a flowchart shown in FIG.

First, the ECU 17 performs idle speed control (ISC control) while the engine is operating (step 201). This ISC control is performed to adjust the opening of the throttle valve 14. For example, the correction amount for the engine water temperature obtained from the water temperature sensor 22, the correction amount for the gear position of the transmission, the correction amount for starting the engine, the lighting, etc. A final correction amount is determined based on correction amounts for various loads such as electric loads, rotation changes, and air conditioner use conditions, and a required throttle valve opening is determined from the final correction amounts. That's what it says.

Further, the ECU 17 obtains not only the required opening of the throttle valve based on the ISC control but also the required opening of the throttle valve in accordance with other various requests (step 202). Other various requirements include, for example, the detection output of the accelerator position sensor 12, that is, the depression amount of the accelerator pedal 21, and the required opening degree of the throttle valve according to the depression amount is obtained.

Then, the ECU 17 obtains the final target opening by adding the required opening of the throttle valve based on the ISC control and the required opening of the throttle valve according to various other requests (step 203). .

Next, the ECU 17 obtains a final target voltage corresponding to the final target opening based on a function indicating a non-linear relationship (step 204), and obtains the final target voltage and the total value of the throttle valve 14 previously learned. The control voltage TTP of the motor 15 is obtained by adding the voltage corresponding to the closed position (step 205).

As a result, the throttle valve 14 is rotated to the final target opening by the motor 15, and a required amount of air is supplied to the engine via the throttle valve 14.

That is, the fully closed position is learned based on the initial position of the throttle valve 14, and the control voltage TTP of the motor 15 is determined in consideration of the fully closed position. To become TTP,
The throttle valve 14 is controlled.

However, as described above, when the mechanically determined initial position of the throttle valve 14 is detected and the fully closed position of the throttle valve 14 is learned based on this initial position, the learned fully closed position is obtained. Errors easily occur. In this case, when the throttle valve 14 is moved to near the fully closed position by the throttle control, the throttle valve 14 hits the stopper, and even after hitting the stopper, the throttle valve 14 tries to push the stopper further. (Hereinafter, this state is referred to as a thrust state of the throttle valve 14).

Therefore, in this embodiment, when the throttle valve 14 is in the pushing state, the opening of the throttle valve 14 is detected by the throttle position sensor 13,
This opening is set as the fully closed position, and the fully closed position is updated. The update of the fully closed position is performed according to the flowchart of FIG. 5 in parallel with the throttle control shown in FIG.

First, the ECU 17 initially sets a predetermined compensation amount Δ to 0 (step 301). And
The ECU 17 determines whether an overcurrent is flowing to the motor 15 that drives the throttle valve 14 (Steps 302 and 303).

When the throttle valve 14 is pushed, the motor 15 is locked, and the motor 1
Since an overload acts on the motor 5 and an overcurrent flows through the motor 15, it is determined whether or not an overcurrent flows through the motor 15.

In step 302, the motor 1
The duty ratio of the pulsed current supplied to the motor 5 is detected, and if the duty ratio is equal to or greater than a predetermined threshold value, it is determined that an overcurrent is flowing through the motor 15.

In step 303, if the current level supplied to the motor 15 is equal to or higher than a predetermined threshold value, it is determined that an overcurrent is flowing through the motor 15.

As long as it is determined that no overcurrent is flowing through the motor 15 (Step 302, No, Step 303, N
o), these steps 302 and 303 are repeated.

If it is determined that an overcurrent is flowing through the motor 15 (step 302, Yes, or step 3).
03, Yes), the ECU 17 sets the throttle position sensor 1
It is determined whether or not the opening degree of the throttle valve 14 detected by Step 3 is equal to or less than a predetermined value, that is, whether or not the throttle valve 14 is close to the fully closed position (Step 3).
04), if the throttle valve 14 is not close to the fully closed position (step 304, No), it is considered that an overcurrent is flowing through the motor 15 due to other causes, not the pushing state of the throttle valve 14, and the step Return to 302.

The ECU 17 also controls the throttle valve 1
4 is equal to or less than a predetermined value and it is determined that the throttle valve 14 is close to the fully closed position (step 3).
04, Yes), time measurement is started by a built-in timer (step 305).

If the overcurrent does not flow through the motor 15 or the throttle valve 14 moves away from the fully closed position (No in step 305) during this time measurement, the time measurement is interrupted and the timer is returned to the initial state. Return to step 302.

When an overcurrent continues to flow through the motor 15 and the throttle valve 14 is near the fully closed position, and the time reaches a predetermined time (step 30).
5, Yes), the opening degree of the throttle valve 14 detected by the throttle position sensor 13 is obtained, and a compensation amount Δ (= 0) is added to the opening degree to obtain a new fully closed position. The closed position is learned again (step 306).

Next, the ECU 17 determines whether or not the compensation amount Δ is equal to or less than a predetermined allowable value (step 3).
07). At this time, since the compensation amount Δ = 0 (Step 307, No), the ECU 17 updates the compensation amount Δ by adding a predetermined small compensation amount θ to the compensation amount Δ (Step 308). Further, after returning the timer to the initial state (step 309), the process returns to step 302.

As described above, when an overcurrent flows to the motor 15 and the throttle valve 14 is close to the fully closed position and this state continues for a predetermined time, the motor 15 is in the locked state, and the throttle valve 14 Since it is in the thrust state, the fully closed position learned by the processing of the flowchart of FIG. 2 is regarded as being erroneous, and the fully closed position is corrected to the opening detected by the throttle position sensor 13, whereby the fully closed position is obtained. The location has been updated.

However, when the motor 15 is overloaded while the throttle valve 14 is being pushed and the throttle valve 14 and the supporting mechanism of the throttle valve 14 are overloaded, the strength of these motors is insufficient. May cause distortion. At this time, even if the opening of the throttle valve 14 is detected by the throttle position sensor 13 and the opening is re-learned as the fully closed position, the accurate fully closed position cannot be learned. In this case, the thrust state of the throttle valve 14 may be caused again in the throttle control of FIG.

If the thrust valve 14 is pushed again while repeating steps 302 to 304, the motor 15 is locked and it is determined that an overcurrent is flowing through the motor 15 (step 30).
2, Yes or Step 303, Yes), it is determined that the throttle valve 14 is close to the fully closed position (Step 304,
(Yes), this state continues for a predetermined time (Step 305, Yes).

Therefore, returning to step 306 again,
The opening degree of the throttle valve 14 detected by the throttle position sensor 13 is obtained, and the opening degree is used as a compensation amount Δ (=
θ) is added to obtain a new fully closed position, and the new fully closed position is learned again. Thereafter, it is confirmed that the compensation amount Δ (= θ) is equal to or smaller than the allowable value (No in Step 307), the minute compensation amount θ is added again to the compensation amount Δ, and the compensation amount Δ is updated to 2θ. (Step 308) Then, after resetting the timer to the initial state (Step 309), Step 302
Return to

The fully closed position obtained in step 306 is corrected by a compensation amount Δ (= θ) as compared with the previously obtained fully closed position, and when the throttle valve 14 is pushed, the throttle position sensor is 13, the compensation amount Δ (= θ) is larger than the opening degree of the throttle valve 14 detected by
This corresponds to a position that is just apart. For this reason, when the throttle valve 14 is moved to the fully closed position by the throttle control, the throttle valve 14 is moved to a position separated by a compensation amount Δ (= θ) from the opening detected in the pushing state. As a result, the probability that the throttle valve 14 is pushed is reduced.

Alternatively, when the error of the opening degree of the throttle valve 14 detected by the throttle position sensor 13 is large when the throttle valve 14 is pushed, the compensation amount Δ (= θ) is added to the detected position. This error cannot be compensated for by simply performing
Again can be pushed.

In this case, while the steps 302 to 304 are being repeated again, the motor 15 is locked and it is determined that an overcurrent is flowing through the motor 15 (step 302, Yes or step 303, Yes). ), It is determined that the throttle valve 14 is close to the fully closed position (Step 304, Yes), and if this state continues for a predetermined time (Step 305, Yes), the throttle valve 14 detected by the throttle position sensor 13 is closed. The compensation amount Δ (= 2θ) is added to the opening to learn a new fully closed position again (step 306). Then, the compensation amount Δ (= 2
θ) is less than the allowable value (step 30).
7, No), the small compensation amount θ is added again to the compensation amount Δ, the compensation amount Δ is updated to 3θ (step 308), and the timer is returned to the initial state (step 309). Return.

Similarly, every time the throttle valve 14 is pushed, the fully closed position is updated and the compensation amount Δ is updated.

If the pushing state of the throttle valve 14 cannot be eliminated even if the compensation amount Δ is sufficiently large, there is a possibility that some trouble has occurred. Therefore, when the compensation amount Δ becomes equal to or larger than the allowable value while repeating the update of the fully closed position and the compensation amount (step 30).
7, Yes), the ECU 17 determines that an abnormality has occurred,
A predetermined fail-safe process is performed (step 310).

As described above, in the above-described embodiment, the fully closed position of the throttle valve 14 is learned before the start of the engine, and when the throttle valve 14 is pushed in the subsequent control of the throttle valve 14, this is detected. The fully closed position is detected based on whether the motor 15 is in the locked state, and the learned fully closed position is corrected to the opening of the throttle valve 14 detected by the throttle position sensor 13 to update the fully closed position. . Further, each time the thrust state of the throttle valve 14 is repeated, the compensation amount Δ is added to the fully closed position, and the fully closed position is sequentially updated. For this reason, it is possible to set an accurate fully closed position that does not cause the throttle valve 14 to be pushed, as the fully closed position of the throttle valve 14.

Further, when the compensation amount Δ becomes too large, a predetermined fail-safe process is performed, so that an abnormal situation can be avoided.

Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in this embodiment, the initial position of the throttle valve 14 is detected, and a position rotated by a predetermined angle from this initial position is determined as the fully closed position of the throttle valve 14. Even when the position is directly detected by the sensor, there is a possibility that the throttle valve 14 may be pushed in the throttle control, so that the present invention can be applied.

[0058]

As described above, according to the present invention, when the motor for driving the throttle valve is in the locked state, the opening degree of the throttle valve detected at this time is set as the fully closed position of the throttle valve. To set,
An erroneous fully closed position can be corrected and an accurate fully closed position can be learned.

In consideration of the distortion of the throttle valve and the support mechanism of the throttle valve in the locked state of the motor, the detected opening degree of the throttle valve is corrected by a predetermined compensation amount. , The fully closed position can be learned more accurately.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of an electronic throttle control device of the present invention.

FIG. 2 is a flowchart showing a process for learning a fully closed position of a throttle valve before starting the engine in the apparatus of FIG. 1;

FIG. 3 is a timing chart showing the timing of the processing in FIG. 2;

FIG. 4 is a flowchart showing throttle control in the apparatus of FIG. 1;

FIG. 5 is a flowchart showing a process for correcting a fully closed position of a throttle valve in the throttle control of FIG. 4;

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 throttle control device 12 double-system accelerator position sensor 13 double-system throttle position sensor 14 throttle valve 15 motor 16 electromagnetic clutch 17 electronic controller unit 21 accelerator pedal 22 water temperature sensor 24 ignition switch 25 switch

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 45/00364 F02D 45 / 00364G

Claims (2)

[Claims] A throttle sensor for detecting an opening degree of a throttle valve; learning a fully closed position of the throttle valve; a throttle valve opening degree detected by the throttle sensor; An electronic throttle control device for an internal combustion engine that drives and controls a throttle valve by a motor based on a closed position, wherein: a detection unit that detects whether the motor is locked; and a motor that is locked by the detection unit. And a learning means for updating the opening of the throttle valve detected by the throttle sensor at this time as the fully closed position of the throttle valve. 2. When the detecting means detects that the motor is in the locked state again, the learning means corrects the detected opening degree of the throttle valve by a predetermined compensation amount, and sets the fully closed state. The electronic throttle control device for an internal combustion engine according to claim 1, wherein the position is updated.