JP2003239765A - Engine control device and computer program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent excessive stepping on an accelerator just after the engine control for securing the safety running of a vehicle is finished by detecting an unstable condition of the vehicle and applying the control for inhibiting the unstableness. <P>SOLUTION: When the torque reduction rate Ds is equivalent to or smaller than a requested torque reduction rate Dt in the step S215, the process advances to the step S217 to apply a prescribed limitation to the control of the throttle opening, and the throttle opening is set at a limited value or the lowest limited value TVO<SB>0</SB>. In the step S218, the number of cylinders to be reduced to fill up the deviation (Dt-Ds) between the requested torque reduction rate Dt and the torque reduction rate Ds and the quantity of retard of the ignition timing are operated and executed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device and its computer program.

[0002]

2. Description of the Related Art A system for ensuring the running stability of a vehicle by detecting the occurrence of an unstable state of the vehicle and adding a control for suppressing the occurrence of the unstable state of the vehicle, while electronic control of an engine is being developed. In many cases, engine control is built in (Japanese Patent Laid-Open No. 2001-88674, Japanese Patent Laid-Open No. 200-88674).
0-213387). Typical examples thereof are slip control (TCS: Traction Control System) and turning control (DSC: Dynamic Stability Control). Turning control, for example, causes a strong understeer tendency when the turning behavior of the vehicle largely deviates from the target behavior. In the case of, the engine output can be reduced to suppress this strong understeer tendency. Further, the slip control can reduce the engine output to suppress excessive slip of the drive wheels when the slip amount of the drive wheels is larger than a predetermined target value.

As specific means for reducing the engine output, ignition timing delay (ignition timing retard), fuel cut for stopping fuel supply to some or all of the cylinders, and throttle opening which is an intake air amount adjusting valve. Reductions are commonly known and they are commonly used in combination. For example, Japanese Unexamined Patent Application Publication No. 2000-213387 relates to engine control in which a throttle opening and the number of fuel cut cylinders are combined, and a target value of the throttle opening is set based on the TCS required torque to determine the primary delay characteristic of the throttle control. Taking into consideration, it is proposed to set the target value of the number of fuel cut cylinders for realizing the TCS required torque early.

[0004]

Among the above three engine output reducing means, the control of the throttle opening has a response delay compared to other engine output reducing means such as ignition timing retard. After the end, for example, when there is an acceleration request, the problem of deterioration of acceleration responsiveness is likely to occur.

Explaining with a concrete example, for example, a state where excessive slip occurs in the drive wheels, or a state where the turning behavior of the vehicle largely deviates from the target behavior and a strong understeer tendency occurs, and a normal driving state is obtained. Immediately after returning to, that is, immediately after the engine control for suppressing the behavior is finished, the acceleration responsiveness deteriorates due to the response delay of the throttle opening, which causes new instability of the vehicle or the driver from a feeling of stall. May feel uncomfortable.

As another example, if acceleration responsiveness is not ensured when the DSC control is completed, the driver may excessively depress the accelerator pedal. Due to the accelerator pedal depression, the turning state becomes strong understeer again. May become.

As still another example, when traveling on a high μ road, T
If acceleration responsiveness is not ensured when the control of the CS is completed, the driver may feel stall.

In order to solve such a problem, for example, if engine control such as TCS is performed by fuel cut and / or ignition timing delay (retard) without throttle opening control, fuel cut and ignition timing retard are performed. Because the torque control of the engine is rougher than the control by the throttle, the smoothness of the TCS control is lost, giving the driver a feeling of discomfort due to the TCS control, and the exhaust gas purification due to the rise in the exhaust gas temperature. There is a possibility that the catalyst for use may deteriorate.

Therefore, an object of the present invention is to detect an unstable state of the vehicle and add a control for suppressing the unstable state to prevent excessive control immediately after the engine control for ensuring the running stability of the vehicle is completed. To provide an engine control device and a computer program therefor capable of suppressing a large accelerator depression.

[0010]

According to one aspect of the present invention, a target torque reduction amount set based on a running state of a vehicle is satisfied when the running state of the vehicle satisfies a predetermined condition. In order to achieve the above, in an engine control device that performs control for reducing the engine output by a combination of an intake air amount adjusting valve and other engine output reducing means, an intake air intake valve is provided with a certain limit for narrowing down the intake air amount adjusting valve. The engine output reduction means for compensating the engine output reduction quantity insufficient to achieve the target torque reduction amount by the other engine output reduction means when the amount reduction restriction means and the intake air amount reduction restriction means are operating. It is achieved by providing a control device for an engine, characterized in that it has complementary means.

That is, when the intake air amount adjusting valve is narrowed down in order to achieve the target torque reduction amount, a certain limit is given to the intake air amount adjusting valve so as to prevent the valve from fully closing, while the insufficient torque is reduced. By causing the amount of down to be associated with another engine output lowering means, it is possible to improve the responsiveness of the engine output to the accelerator depression immediately after the engine control for achieving the running stability of the vehicle is completed. It is possible to prevent the driver from excessively stepping on the accelerator.

According to another aspect of the present invention, the above object is
The computer that controls the engine of the vehicle controls the intake air amount adjustment valve and other engine outputs to achieve a target torque reduction amount set based on the traveling state of the vehicle when the traveling state of the vehicle satisfies a predetermined condition. A means for reducing the engine output by a combination with a reducing means, a means for providing a constant limit to the throttle of the intake air amount adjusting valve, and a target torque reduction amount when the intake air amount limiting means is operating. This is achieved by providing a computer program for causing the other engine output reduction means to supplement the engine output reduction amount that is insufficient to achieve it.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiment of the present invention, the certain limit is changed depending on the operating state of the engine, for example, during warming of the engine and during cold of the engine. For example, when warm, the lower limit value of the opening of the intake air amount adjustment valve is set relatively high to enhance the responsiveness, while when cold, the lower limit value of the opening amount of the intake air amount adjustment valve is relatively increased. By setting it low, it is possible to smooth the increase in engine output when the accelerator is depressed.

Further, when the control for reducing the engine output includes the turning state control and the slip state control, in the turning state control, the driver excessively accelerates due to a response delay immediately after the end of this control. Therefore, the lower limit value of the opening of the intake air amount control valve due to the restriction of the throttle of the intake air amount control valve is set to a larger opening in the turning state control than in the slip state control. It is preferable to set.

Further, in the slip state control, on a high μ road, the driver is likely to feel a stall due to a response delay immediately after the slip state control is completed, so the above-mentioned fixed limit is changed according to the magnitude of the road surface friction coefficient. However, it is preferable to set the lower limit value of the opening degree of the intake air amount adjusting valve due to the restriction of the narrowing down of the intake air amount adjusting valve to a larger opening amount when the road surface friction coefficient is higher than when it is small.

Further, at the time of starting where there is a large possibility that the torque reduction amount will increase due to continuous slip state control for a relatively long period of time, in order to realize smooth engine output increase immediately after the slip state control is completed, road surface friction is increased. When the coefficient is small and the vehicle is started, when the accelerator opening is large, the lower limit value of the opening of the intake air amount adjusting valve is set to a small opening as compared with when the accelerator opening is small, by limiting the narrowing of the intake air amount adjusting valve. Is preferred.

Further, since the combustion of the engine is unstable when the engine is cold, the lower limit value of the opening of the intake amount adjustment valve due to the restriction of the narrowing of the intake amount adjustment valve is set to the warm value when the engine is cold. It is preferable to set the opening to be smaller than that for the short time so that the engine output can be smoothly increased after the engine control for realizing the running stability of the vehicle is completed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows the turning state control, that is, DS
C and a slip state control, that is, a DSC / TCS control unit 20 for performing brake control in TCS,
Engine control unit 30 for performing engine control
FIG. 3 is an overall configuration diagram showing an input / output relationship between a sensor and various actuators driven by various sensors and various control units.

In this embodiment, the engine control unit 30
As an engine controlled by the above, an example applied to an internal combustion engine provided with a fuel injection valve and a spark plug for each cylinder is shown. This engine is, for example, a 4-cylinder engine, and is mounted on a front-wheel drive type vehicle. The control in DSC and TCS is performed based on the difference between the speed of the front wheels (driving wheels) and the speed of the rear wheels (driven wheels).

The DSC / TCS control unit 20 includes a wheel speed sensor 1 for detecting the wheel speed of the right front wheel FR (right drive wheel) and a wheel speed sensor for detecting the wheel speed of the left front wheel FL (left drive wheel). Speed sensor 2, wheel speed sensor 3 for detecting the wheel speed of the right rear wheel RR, left rear wheel RL
Wheel speed sensor 4, yaw rate sensor 5, lateral acceleration sensor 6, steering angle sensor 7 for detecting the steering angle θ of the steering wheel, road surface slipperiness (road surface μ, that is, road surface friction coefficient) Road surface μ for detecting
The detection value of each of the sensors 8 is input. Regarding the input of the road surface μ, the role of the road surface μ sensor 8 may be substituted by receiving the vehicle exterior information regarding the road surface μ transmitted from the infrastructure, and the road surface μ may be changed from the acceleration during the operation of the TCS control. May be determined (the larger the acceleration, the larger the road surface μ).

The DSC / TCS control unit 20 independently controls the brake actuators 9 provided corresponding to the respective wheels based on a computer program stored in the memory. Is determined by the turning state determination means 20a for determining the turning state of the vehicle, the driving wheel spin determination means 20b for determining the spin state of the driving wheels, the turning state determination means 20a or the driving wheel spin determination means 20b. Based on the turning state or the driving wheel slip state determined by the target braking force calculating means 20c and the turning state determining means 20a or the driving wheel spin determining means 20b which calculate the target braking force based on the turning state or the driving wheel slip state. Calculate the required torque to reduce the driving force (torque). And a target driving force calculating unit 20d.

In the figure, reference numeral 10 is a lighting lamp which is turned on while the vehicle turning state control (DSC control) is being performed, and 11 is being turned on while the drive wheel slip state control (TCS control) is being performed. It is a lighting lamp.

The engine control unit 30 is sucked into the engine by an accelerator opening sensor 13 for detecting an accelerator opening, an engine water temperature sensor 14 for detecting an engine water temperature, that is, a cold temperature, an engine speed sensor 15 for detecting an engine speed. Air flow sensor 1 for detecting the amount of air
The detected value of 6 and the required torque calculated by the DSC / TCS control unit 20 or the target driving force calculation means 20d are input.

The engine control unit 30 independently operates a throttle valve 17, which is an intake air amount adjusting means, a fuel injection valve 18 for each cylinder, and an igniter 19, which is an ignition timing changing means, based on a computer program stored in a memory. Then, it is controlled.

During the DSC control or the TCS control, the engine control unit 30 gives a certain limit (limit value or lower limit value) to the decrease in the throttle opening to realize the required torque reduction amount, but is insufficient. The amount of torque reduction to be performed is
Complemented by fuel cut and / or ignition retard.

The details of the control based on each of the control units 20 and 30 will be described below with reference to FIGS.

(Brake Turning Control (DSC)) FIG. 2
First, in step S1, the detected values of the wheel speed sensors 1 to 4, the detected value of the yaw rate sensor 5, the detected value of the lateral acceleration sensor 6, the detected value of the steering angle sensor 7, and the base calculated by the engine control unit 30. The engine torque is input.

In step S2, each wheel speed sensor 1 to
Among the four detection values, the average value is calculated based on three detection values excluding the maximum value, and the average value is set as the vehicle body speed V. Next, in step S3, the first target yaw rate value ω1 is calculated based on the vehicle speed V and the steering angle θ. Specifically, the calculation is performed based on the following formula.

Ω1 = V × θ × ((1-k × V × V) × L) Where V: vehicle speed θ: Steering angle k: constant specific to the vehicle body L: Wheel base

In step S4, the second target yaw rate value ω2 is calculated based on the ratio of the vehicle body speed V to the lateral acceleration. In step S5, a larger value of the first target yaw rate value ω1 calculated in step S3 and the second target yaw rate value ω2 calculated in step S4 is set as the final target yaw rate ωT, and in step S6, A deviation Δω between the final target yaw rate ωT set in S4 and the actual yaw rate ωr detected by the yaw rate sensor 5 is calculated.

In step S7, it is determined whether or not the counterclockwise yaw rate is equal to or higher than a predetermined value and the vehicle is turning left. If the determination is YES, the process proceeds to step S8. Then, in step S8, the deviation Δω calculated in step S6 is the threshold value Thos1.
If it is determined to be YES (a non-zero positive value) or more, and if YES is determined, it can be determined that the vehicle is oversteered while the vehicle is turning to the left. After setting to "1",
In step S10, the brake actuator 9 is controlled to increase the braking force of the turning outer wheel (right wheel) as Δω increases.

If NO is determined in step S8, the process proceeds to step S11, and the deviation Δ calculated in step S6 is calculated.
It is determined whether or not ω is smaller than the threshold value Thus1 (negative value other than 0). If YES is determined in step S11,
Since it can be determined that the vehicle is in an understeer state while turning left, in step S12, the TCS control prohibition flag FD that prohibits TCS control is set to "1" as in step S9. The brake actuator 9 is controlled to increase the braking force of.

The reason why the TCS control is prohibited in step S12 is to avoid interference with the TCS control. Subsequently, in step S14, engine control is also executed, and in order to quickly return the understeer state during left turn to the normal state, the engine control unit 30 to be described later should increase the torque reduction amount as Δω increases.
The required torque after torque down is calculated based on the current base engine torque calculated in step 1. For example, the required torque is calculated by subtracting the engine torque down amount corresponding to Δω from the current base engine torque. Output to the control unit 30.

If NO is determined in step S7, the process proceeds to step S15. In step S15, it is determined whether the clockwise yaw rate is a predetermined value or more and whether the vehicle is turning right. If so, in the next step S16, it is determined whether or not the deviation Δω calculated in step S6 is less than or equal to a threshold value Thos2 (a negative value other than 0), and YE
When it is determined to be S, it is possible to determine that the steering is an oversteer state while the vehicle is turning right. Therefore, in step S17, the TCS control prohibition flag FD for prohibiting the TCS control is set to "1" as in steps S9 and S12. After setting, in step S18, the brake actuator 9 is controlled to increase the braking force of the turning outer wheel (left wheel) as Δω increases.

When NO is determined in the step S16,
In step S19, it is determined whether the deviation Δω calculated in step S6 is larger than the threshold value Thos2 (a positive value other than 0). When YES is determined in step S19, it can be determined that the understeer state is in the right turn, and therefore, in step S20, the previous steps S9 and S are performed.
Similar to 12 and S17, after setting the TCS control prohibition flag FD for prohibiting TCS control to "1", in the next step S21, the brake is applied to increase the braking force of the turning inner wheel (right wheel) as Δω increases. The actuator 9 is controlled. Then, in the next step S22, the previous step S1
Similar to 4, in order to increase the torque reduction amount as Δω increases, the required torque is calculated based on the current base engine torque and output to the engine control unit 30.

When NO is determined in any of steps S11, S15, and S19, the DSC control is not performed, and the process proceeds to step S23 to reset the TCS control prohibition flag FD to 0.

(TCS Control by Brake) In FIG. 4, in step S100, various sensor detection values are input as in step S1 in FIG.
In 01, the vehicle body speed V is calculated as in step S2 of FIG. That is, the vehicle body speed V is determined by each wheel speed sensor 1
It is determined by calculating an average value based on three detection values excluding the maximum value among the detection values of ~ 4.

In step S102, the right drive wheel slip amount ΔVr is calculated based on the difference between the wheel speed of the right front wheel FR (right drive wheel) and the vehicle body speed V, and in step S103, the left front wheel FL (left drive wheel). ) Wheel speed and vehicle speed V
The left drive wheel slip amount ΔVl is calculated based on the difference between The slip ratio {1- (vehicle body speed / driving wheel speed)} may be used instead of the slip amount (driving wheel speed-vehicle body speed V).

Then, in step S104, step S
102 or it is determined whether one of the right drive wheel slip amount Vr and the left drive wheel slip amount Vl calculated in step S103 is greater than or equal to the engine control TCS control start threshold V0, and it is determined YES in step S104. If so, the process proceeds to step S105.

In step S105, it is judged from the state of the above-mentioned TCS control prohibition flag FD whether or not the DSC control is in progress, and N
When it is determined to be O, in step S106, step S1
02, right drive wheel slip amount ΔV calculated in S103
The required torque is calculated based on the current base engine torque so that the larger the slip amount, the larger the torque reduction amount becomes based on the larger one of r and the left drive wheel slip amount ΔVl. Control unit 30
Output to. The calculation of the required torque is the same as steps S14 and S22 in FIG.

Then, in step S107, step S
102, right drive wheel slip amount calculated in S103
It is determined whether or not one of Vr and the left drive wheel slip amount ΔVl is equal to or greater than the brake control TCS control start threshold VB. The brake control TCS control start threshold value VB is
It is set to a value larger than the TCS control start threshold value V0 for engine control. If YES is determined in the step S107, the process proceeds to a step S108, and the step S10 is performed.
2. Right drive wheel slip amount ΔVr calculated in S103
Based on the larger slip amount of the left drive wheel slip amount ΔVl and the left drive wheel slip amount ΔVl, the brake actuator 9 is controlled so that a larger braking force is applied to the drive wheel.

If NO is determined in step S107, it is not necessary to perform TCS control by brake control.
The process returns without performing the process of step S108.
Also, when it is determined NO in step S104,
Since it is not necessary to perform TCS control by engine control and TCS control by brake control, steps S1O6, S1
The process returns without performing the process of 08. When it is determined to be YES in step S105, the process returns without performing TCS control in order to avoid interference with DSC control.

(DSC and TCS Control by Engine) In FIG. 5, in step S200, accelerator opening detected by the accelerator opening sensor 13, engine warm / cold information detected by the engine water temperature sensor 14,
The engine speed detected by the engine speed sensor 15, the intake air amount detected by the air flow sensor 16, the road surface μ information from the engine control unit 30, and the vehicle speed are input to the engine control unit 30, respectively. Next, in step S201, a throttle opening TVOo as a limit value or a lower limit value when a certain limit is set for throttle opening control described later is set by a subroutine such as FIG.

Next, in step S202, DSC /
DSC control or TCS from the TCS control unit 20
It is determined whether or not there is a torque reduction request based on the control.
That is, step S14 and step S22 in FIG.
Alternatively, it is determined whether or not the required torque amount calculated in step S106 in FIG. 4 is output to the engine control unit 30.

If YES in step S202, it is determined in step S203 whether or not the timer T is greater than zero, and when the timer T is zero, that is,
When the torque down request is received at the beginning, the timer T is set to "1" and then the process proceeds to step S206. The next time when step S203 is reached, the timer T
Is not zero, the process proceeds from step S203 to step S204, the timer T is incremented by "1", and then the process proceeds to step S206.

In step S206, depending on the current operating state of the engine, for example, engine speed, intake air amount, fuel injection amount (value calculated based on engine speed, intake air amount, etc.), ignition timing, etc. Then, the present base engine torque (engine output torque before execution of DSC control and TCS control, that is, when both controls are not performed) is calculated.

Then, in the next step S207 (FIG. 6), the required torque output from the brake control unit 20 is divided by the gear ratio of the transmission to calculate the required engine torque. Then, in step S208, the required torque down rate Dt is calculated based on the base engine torque calculated in step S206 and the required engine torque calculated in step S206. The required torque reduction rate Dt is calculated, for example, by the following formula.

Required torque reduction rate Dt = {(base engine torque-request torque) / base engine torque}

In step S209, step S207
It is determined whether or not the required torque reduction rate calculated in step 3 is smaller than the engine stall. Here, the Enstguard is
The torque down control is restricted by the torque down control based on the DSC control or the TCS control so that the engine does not stall, and is set to a smaller value as the engine speed is lower.

If YES is determined in the step S209, it is determined in a next step S210 whether or not a predetermined time To has passed since the torque down control by the DSC control or the TCS control was started. Step S21
When it is determined to be NO (before the elapse of the predetermined time To, that is, the initial stage of starting the torque down control), the step S2
In step 11, the number Nf of fuel cut cylinders is set according to the required torque reduction rate, and fuel cut, which is means for reducing the engine output, is executed. The number Nf of fuel cut cylinders corresponding to the required torque reduction rate is set based on the following table, for example.

[0051]   Required torque reduction rate (%) Number of fuel cut cylinders (Nf)   0 ≤ required torque reduction rate <250   25 ≦ required torque reduction rate <50 1   50 ≦ required torque reduction rate <75 2   75 ≦ required torque reduction rate <100 3   Required torque reduction rate = 100 4

In the following step S212, step S
The required engine torque calculated in 207 and step S
The retard amount of the ignition timing is set from the map based on the number Nf of the fuel cut cylinders set in 211, and the fuel cut and the retard of the ignition timing are executed in the next step S213. That is, the engine torque reduction amount is adjusted to the required torque reduction rate by the combination of the number of fuel cut cylinders Nf and the retard of the ignition timing. In accordance with the amount of reduction, the retard amount of ignition timing as another engine output reduction means is set, and linear torque reduction control is performed.

As described above, at the initial stage of starting the torque reduction control, the required torque reduction is achieved by the combination of the fuel cut control and the ignition timing retard control, which are excellent in responsiveness, without performing the throttle opening control which is the engine output reducing means. The rate can be realized.

On the other hand, if YES in the previous step S210, that is, after the torque down control by the DSC control or the TCS control is started and a certain time has passed (after a predetermined time To has passed), the process proceeds to step S214 and is executed. The engine torque when the middle fuel cut control and / or the ignition timing control is stopped is estimated, and the torque reduction rate Ds when the throttle opening is changed to TVOo from this state is estimated.

Then, in the next step S215, DSC
If the torque reduction rate Ds is larger than the required torque reduction rate Dt when the torque reduction control or the TCS control is all performed by narrowing the throttle opening, the throttle opening control is performed without performing control such as fuel cut. Since it is possible to sufficiently achieve the required torque reduction rate by itself, the process proceeds to step S216, the throttle opening corresponding to the required torque reduction rate Dt is obtained from the map, and the torque reduction by this throttle opening is performed. Run.

When the torque down rate Ds is equal to or smaller than the required torque down rate Dt in step S215, the process proceeds to step S217 to give a certain limit to the throttle opening control, and the throttle opening degree is increased. Is set to the limit value or the lower limit value TVOo, and in the next step S218, the number of cylinders capable of filling the deviation (Dt-Ds) between the required torque down rate Dt and the torque down rate Ds is cut and the ignition timing retard amount is set. Is executed and this is executed. As a result, the throttle opening is performed at the predetermined limit value or the lower limit value TVOo set in step S201, without making the throttle opening fully closed or almost completely closed. /
Alternatively, it is supplemented by ignition timing retard. That is,
By setting a certain limit or lower limit on the throttle opening to give a certain limit to the throttle narrowing down, the shortage of torque reduction with respect to the required torque reduction amount can be reduced by the number of cylinders and / or
Alternatively, it is compensated by increasing the torque reduction due to the ignition timing retard.

If NO in the previous step S202 (after the lapse of a predetermined time), it is determined that the engine is in a normal operating state, the process proceeds to step S219, the timer T is reset to zero, and then the accelerator is operated in step S220. A throttle opening degree is set according to the opening degree and is executed. Then, in step S221, normal engine control is executed according to the detection values of the accelerator opening degree sensor 13 and the air flow sensor 16. As a result, in the engine control by the DSC / TCS, at the beginning of the control, the torque reduction is executed by the control of the number of cylinders and the ignition timing retard, which are excellent in responsiveness, without the throttle opening control. After the lapse of time, the throttle opening control is mainly performed, and the torque reduction is executed by additionally controlling the number of cylinders and the ignition timing retard.

7 to 9 are flowcharts for explaining a subroutine for setting a limit value or lower limit value TVOo used for throttle opening control in DSC / TCS.

In FIG. 7, in step S300, TC
It is determined whether or not the S control prohibition flag FD is "1" (TCS control prohibition), and when the flag FD is "1", DS
Assuming that the C control is being executed, the process proceeds to step S301, and the throttle opening 10% is set as the throttle limit value or the lower limit value TVOo.

When NO is determined in the previous step S300, it is determined that the TCS control is being performed, and the step S30 is performed.
Then, the routine proceeds to 2 to judge whether the road surface friction coefficient (road surface μ) is larger than a predetermined value. YES in this step S302
That is, when it is determined that the road is a high μ road, step S3
In step 03, the throttle opening 8% is set as the limit value or the lower limit value TVOo.

If NO in the previous step S302, that is, if it is determined to be a low μ road, the flow advances to step S303 to set the throttle opening 4% as the limit value or lower limit value TVOo.

Here, "10%" in step S301,
“8%” in step S303, and step S304
The numerical value of "4%" itself does not have a particularly important meaning. What is important here is that by setting the limit value or lower limit value TVOo of the throttle opening, the DSC
During the control or the TCS control, the throttle is always closed without the throttle being fully closed, and the insufficient amount for the required torque reduction amount is the engine output reduction complementing means including fuel cut and / or ignition timing retard. Is to be supplemented by. As a result, the responsiveness of the engine output can be improved when the accelerator is depressed immediately after the DSC control or the TCS control is completed.

Further, the throttle opening limit value or lower limit value is set to "10%" during the DSC control, and at other times, that is, during the TCS control, the throttle opening lower limit value is set on the high μ road. Set it to "8%", and on low μ roads, set "4%", which is relatively smaller than on high μ roads, to the throttle opening lower limit value to give a value according to the driving condition and running condition. I am doing it.

As a result, in this situation, a relatively high throttle opening lower limit value is given to the accelerator depression immediately after the DSC control is finished or immediately after the TCS control is finished on the high μ road. It is possible to secure a quick response of the engine output against. As a result, the driver can feel the increase in the engine output according to the depression of the accelerator, so that the risk of excessive accelerator operation can be reduced, and therefore the excessive behavior of the vehicle after the DSC control or the TCS control is finished. Change can be prevented. Especially, during DSC control, TCS
Since it is set to "10%", which is relatively higher than that during control, it is effective for ensuring vehicle running stability in DSC control in which response delay of engine output easily induces instability of the vehicle attitude. Is.

Further, on a relatively slippery low μ road, since a relatively low throttle opening lower limit value is given, the engine output smoothly rises when the accelerator is depressed immediately after the TCS control is completed. It is possible to prevent a sensitive behavior change of the vehicle on a low μ road.

Of course, the appropriate limit value or lower limit value TVOo in each driving situation is determined by the DSC control or the TVo in consideration of the road surface condition, engine capacity, vehicle characteristics, etc. at the design stage.
The optimum value that can realize the responsiveness suitable for the situation immediately after the end of the CS control may be arbitrarily selected.

Regarding the setting of the limit value or the lower limit value of the throttle opening in the TCS control, the road surface friction coefficient, that is, the slipperiness of the road surface is divided into multiple steps such as 5 steps, and the throttle value corresponding to each step is set. A limit value or a lower limit value of the opening may be set, and at this time, the lower limit value of each stage may be set so that the lower limit value of the throttle opening becomes relatively higher on the higher μ road.

Further, the setting step (S300, S30) of the lower limit value TVOo according to the presence or absence of the DSC control in FIG.
1) may be omitted, and TVOo may be set according to the road surface μ.

FIG. 8 is a flow chart showing an example of another setting regarding the limit value or the lower limit value TVOo. This Figure 8
In step S400, the TCS control prohibition flag
Determine whether the FD is "1" (TCS control prohibited),
When the flag FD is "1", it is determined that the DSC control is being executed, the process proceeds to step S401, and the throttle opening 10% is set as the throttle limit value or the lower limit value TVOo.

If NO in the previous step S400, it is determined that the TCS control is in progress, and the step S40 is performed.
In step 2, it is determined whether the engine is warm or cold depending on whether the engine water temperature is higher than a predetermined value. If YES in step S402, that is, if it is determined that the engine is warm, the flow advances to step S403 to set the throttle opening 8% to the limit value or the lower limit value TVO.
Set as o.

If NO in the previous step S402, that is, if it is determined that the engine is cold, step S40
3, the throttle opening 4% is set to the limit value or the lower limit value T.
Set as VOo.

Here, "10%" in step S401,
“8%” in step S403, and step S404
The meaning of the numerical value of “4%” and the like is substantially the same as that described in FIG. Since a relatively high lower limit value is given in the warm state, quick responsiveness to accelerator depression can be realized. On the other hand, since a relatively low lower limit value is given in the cold state, it is possible to realize a smooth increase in engine output when the accelerator is depressed.

As in FIG. 7, even in the case of FIG.
The appropriate limit value or lower limit value TVOo at the time of engine warming and cold time is the optimum engine output responsiveness and smooth engine output considering the ability of the engine and the characteristics of the vehicle at the design stage. The optimum value may be arbitrarily selected so as to increase.

FIG. 9 is a flow chart showing an example of another setting regarding the limit value or the lower limit value TVOo. This Figure 9
In step S500, it is determined whether the vehicle is starting. This determination may be performed when the vehicle body speed V is, for example, 20 Km / h or less, and as another determination method, the vehicle body speed V is, for example, 7 Km / h or less and is determined from the accelerator depression. It may be determined that the vehicle is starting when the time has elapsed.

If it is determined to be YES in step S500, it is determined that the vehicle is starting, and step S50 is performed.
In step 1, it is determined whether the road surface friction coefficient is larger than a predetermined value. If YES in step S501, that is, if it is determined that the road is a high μ road, the flow advances to step S502 to set a relatively high throttle opening 10% as a throttle limit value or lower limit value TVOo. As a result, as in step S303 of FIG. 7, the DS
It is possible to improve the responsiveness of the engine output to the depression of the accelerator immediately after the C control or the TCS control is finished.

If NO in step S501, that is, if it is determined to be a low μ road, the flow advances to step S503 to determine whether the accelerator opening is larger than a predetermined value. If YES in step S503, that is, if the accelerator opening is relatively large, it is determined that the TCS control has continued for a relatively long time, and the process proceeds to step S504 to set a relatively small throttle opening 4% to the throttle limit value or the lower limit value. Set as TVOo. As a result, the engine output can be relatively smoothly increased when the accelerator is depressed immediately after the end of the TCS control.

If NO in step S503, that is, if the accelerator opening is relatively small, it is determined that the duration of the TCS control is relatively short, and the process proceeds to step S505 to set a relatively large throttle opening 8% to the throttle limit value or the lower limit value. Set as TVOo. As a result, it is possible to secure the responsiveness to the depression of the accelerator immediately after the end of the TCS control.

If NO at step S500, that is, if it is determined that the vehicle is running, step S506.
If it is determined that the engine water temperature is higher than a predetermined value, and if it is NO, that is, if it is cold, the process proceeds to step S504, and a relatively small throttle opening of 4% is throttled. Set as the limit value or lower limit value TVOo.

If YES in step S506, that is, when it is determined that the engine is warm, step S507.
Then, in step S507, it is determined whether the accelerator opening is larger than a predetermined value. This step S50
If YES in step 7, that is, if the accelerator opening is relatively large, it is determined that the TCS control has continued for a relatively long time, and the process proceeds to step S508, and the relatively small throttle opening 8% is set to the throttle limit value or the lower limit value TVOo. Set as. On the other hand, if NO in step S507, that is, if the accelerator opening is relatively small, it is determined that the duration of the TCS control is relatively short, and the process proceeds to step S509 to set a relatively large throttle opening 10% to the throttle limit value or the lower limit value. Set as TVOo. As a result, it is possible to secure the responsiveness to the depression of the accelerator immediately after the end of the TCS control.

(Modification of DSC and TCS control by engine
Shape example) FIGS. 10 and 11 show the DS by the engine described above.
12 is a flowchart showing a modified example of C, TCS control (FIGS. 5 and 6), in which the last two digits of the three-digit step number shown in FIGS. 10 and 11 are replaced with the three-digit step shown in FIGS. By using the same two digits as the last two digits of the number, the description of steps substantially the same as those in FIGS. 5 and 6 is omitted.
0, the characteristic part of the DSC and TCS control by the engine shown in FIG. 11 will be described.

DS by the engine shown in FIGS. 10 and 11.
In C and TCS control, the closing rate TVOR is used for DS
The throttle opening limit value or the lower limit value in C and TCS control is set. That is, step S60
At 1, a predetermined closing rate TVOR is set. Then, in step S614, the engine torque when the fuel cut and / or the ignition timing retard control that is being executed is stopped is estimated, and from that state, the throttle is calculated by multiplying the current throttle opening by a predetermined closing rate TVOR. The torque reduction rate Ds when the throttle is closed up to is estimated. In step S617, the throttle opening lower limit value or limit value VTOo is set by multiplying the current throttle opening by a predetermined closing rate TVOR.

FIG. 12 shows the DSC shown in FIGS. 10 and 11.
/ Close rate T used for throttle opening control in TCS
6 is a flowchart for explaining a subroutine for setting VOR.

In FIG. 12, in step S700, T
It is determined whether or not the CS control prohibition flag FD is "1" (TCS control prohibition), and when the flag FD is "1", D
Assuming that the SC control is being executed, the process advances to step S701 to set a closing rate of 5%.

If NO is determined in the previous step S700, it is determined that the TCS control is being performed, and the step S70 is performed.
Then, the routine proceeds to 2 to judge whether the road surface friction coefficient (road surface μ) is larger than a predetermined value. YES in step S702
That is, when it is determined that the road is a high μ road, step S7
Proceed to 03 to set a closing rate of 10%. Step S7
If NO in 02, that is, if it is determined to be a low μ road, the flow advances to step S704 to set a closing rate of 20%.

Here, "5%" in step S701, "10%" in step S703, and step S704.
The numerical value of "20%" itself does not have a particularly important meaning. What is important here is that by setting this predetermined closing rate TVOR, the throttle opening lower limit value or limit value during DSC control is suppressed to a relatively large value,
It is possible to secure responsiveness to accelerator depression immediately after the end of DSC control, and during the TCS control, the throttle opening lower limit value is suppressed to a relatively large value on the high μ road, and immediately after the end of DSC control. Responsiveness to accelerator depression on the other hand, on the other hand, by setting a relatively small throttle opening lower limit value on low μ road, smooth engine output against accelerator depression on low μ road Can be raised.

Of course, an appropriate closing rate TVOR in each driving situation
At the design stage, taking into consideration road conditions, engine capacity, vehicle characteristics, etc., to realize responsiveness or a smooth increase in engine output suitable for the situation immediately after the end of DSC control or TCS control. It is sufficient to arbitrarily select the optimum value that can be achieved.

Regarding the setting of the closing rate TVOR in the TCS control, the road surface friction coefficient, that is, the slipperiness of the road surface is divided into multiple steps such as 5 steps, and the closing rate is set according to each step. At this time, the closing rate TVOR at each stage may be set such that the closing rate increases as the road has a lower μ.

Further, the lower limit value TVOo setting step (S700, S7) according to the presence or absence of the DSC control in FIG.
01) may be omitted and TVOo may be set according to the road surface μ.

Regarding the setting of the closing ratio TVOR, it is needless to say that the closing ratio may be set according to each operating condition or road surface condition by a method substantially the same as that of FIGS. 8 and 9 described above. Is.

In the above-mentioned embodiment, the example applied to the 4-cylinder engine is shown, but it may be applied to an engine having other number of cylinders such as a V-type 6-cylinder engine. Further, in the above-described embodiment, an example in which the computer program for executing the control according to the present invention is stored in the memory of the engine control unit 30 and executed is described. However, a storage medium separate from the engine control unit 30 ( It may be stored in a CD-ROM or the like and executed. Alternatively, the computer program may be acquired via a wireless communication means such as the Internet and stored in a rewritable ROM so that the computer program can be executed.

[Brief description of drawings]

FIG. 1 is a control system configuration diagram.

FIG. 2 is a flowchart showing a part of brake DSC control contents.

FIG. 3 is a flowchart showing the rest of the brake DSC control content.

FIG. 4 is a flowchart showing brake TCS control contents.

FIG. 5 is a flowchart showing a part of engine control contents.

FIG. 6 is a flowchart showing the rest of the engine control contents.

FIG. 7 is a flowchart showing an example of setting a limit value or a lower limit value of a throttle opening.

FIG. 8 is a flowchart showing another example of setting a throttle opening limit value or a lower limit value.

FIG. 9 is a flowchart showing another example of setting a throttle opening limit value or a lower limit value.

FIG. 10 is a flowchart showing a part of engine control contents of a modified example.

FIG. 11 is a flowchart showing a remaining part of engine control contents of a modified example.

FIG. 12 is a flowchart showing an example of setting a closing rate of a throttle opening.

[Explanation of symbols]

17 Throttle valve 18 Fuel injection valve 19 Igniter 20 DSC / TCS control unit 30 engine control unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 41/04 330 F02D 41/04 330G 3G301 43/00 301 43/00 301B 301H 301K F02P 5/15 F02P 5 / 15 L (72) Inventor Koji Endo 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima F-term in Mazda Co., Ltd. (reference) 3G022 DA02 DA10 GA05 GA06 GA08 GA09 GA19 3G065 CA10 DA04 EA00 EA02 FA05 FA08 GA00 GA05 GA09 GA10 GA11 GA46 GA49 KA36 3G084 BA05 BA13 BA17 DA17 EA11 FA04 FA05 FA07 FA10 FA20 FA33 3G092 AA01 AB02 BA09 BB10 CA07 DC03 EA09 EA13 EA17 FA35 GA02 GB01 GB07 HA01 DB HE01Z HE08Z DA05 CB09DA050903 EA08 EA09 EB04 FA11 FB02 FB05 3G301 HA01 HA07 JA38 KA02 KA05 KB01 KB06 LA00 LA03 LB 03 MA24 NA08 NC02 NE19 NE23 PA01Z PE01Z PE08Z PF00 PF03Z PF15Z PG00

Claims (7)

[Claims] 1. When an operating condition of a vehicle satisfies a predetermined condition, an intake air amount adjusting valve and other engine output reducing means are provided to achieve a target torque reduction amount set based on the operating condition of the vehicle. A control device for an engine that performs control for reducing an engine output by a combination, wherein an intake air amount limiting means for providing a certain limit to the narrowing down of the intake air amount adjusting valve, and the intake air amount limiting means operating In addition, the engine control device further includes an engine output reduction supplementing unit that supplements the engine output reduction amount insufficient to achieve the target torque reduction amount by the other engine output reduction unit. 2. The engine control device according to claim 1, wherein the fixed limit is changed according to an operating state of the engine. 3. The control for reducing the engine output includes a turning state control and a slip state control, and a lower limit value of an opening degree of the intake air amount adjusting valve due to restriction of narrowing down of the intake air amount adjusting valve is 3. The engine control device according to claim 1, wherein the opening degree is set to be larger in the turning state control than in the slip state control. 4. The fixed limit is changed according to the magnitude of the road surface friction coefficient, and the lower limit value of the opening of the intake air amount adjustment valve due to the restriction of narrowing down of the intake air amount adjustment valve has a high road surface friction coefficient. The engine control device according to claim 1, wherein the opening degree is set to a larger opening than when the opening is small. 5. The fixed limit is changed according to the magnitude of the road surface friction coefficient, and the lower limit value of the opening of the intake air amount adjustment valve due to the restriction of narrowing down the intake air amount adjustment valve is such that the road surface friction coefficient is small. The engine control device according to claim 1, wherein when the vehicle is started, the opening is set to be smaller when the accelerator opening is larger than when the opening is small. 6. The fixed limit is changed according to the engine water temperature, and the lower limit value of the opening of the intake air amount adjusting valve due to the restriction of narrowing down of the intake air amount adjusting valve is The engine control device according to claim 1, wherein the opening is set to be smaller than the opening. 7. A computer for controlling an engine of a vehicle is provided with an intake air amount adjusting valve for achieving a target torque reduction amount set based on the traveling state of the vehicle when the traveling state of the vehicle satisfies a predetermined condition. And a means for lowering the engine output by a combination with other engine output reducing means, means for providing a constant restriction on the restriction of the intake air amount adjusting valve, and A computer program for causing an engine output reduction amount, which is insufficient to achieve a target torque reduction amount, to function as a means for complementing the engine output reduction amount.