JP2966154B2 - Engine torque down control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine torque reduction control device, and more particularly to an engine torque reduction control device for a vehicle provided with a traction control system for reducing a driving force when a driving wheel slips.

[0002]

2. Description of the Related Art Generally, a driving force of a vehicle is controlled by adjusting an engine output by a driver's accelerator operation or by operating a transmission. In order to prevent slippage due to excessive driving force, a traction control system that automatically controls the driving force in a restraining direction has been put into practical use, in addition to the control by the operation of the driver as described above.

As a system for realizing this kind of traction control, there are a system for lowering the engine output, a system for applying a braking force to a driving wheel having an excessive driving force by using a brake system, and a system for using these together. As a method for lowering the engine output, for example, Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent Publication No. 33, when a slip value of a drive wheel with respect to a road surface exceeds a predetermined slip determination value,
There is a type in which the engine output is reduced by controlling the opening of the throttle valve in a decreasing direction. According to this, the engine output is reduced when the drive wheel is in the slip state, so that an excessive drive force is prevented from being transmitted to the drive wheel.

[0004]

However, the prior art described in the above publication also has the following problems. That is, for example, in cold regions, the road surface μ
(Friction coefficient) is not constant and the road surface
There are often high μ roads with high. When the vehicle is traveling on such a road surface, the engine output is reduced regardless of the driver's intention each time the drive wheel gets on the low μ road, and this makes the driver feel uncomfortable.

Further, in a place where corners are continuous, such as a winding road, even when the road surface μ is high, the gripping force of the driving wheel decreases during cornering, so that the driving wheel slips depending on the depression state of the accelerator pedal. Therefore, in this case, the same problem as described above occurs.

The present invention addresses the above-described problem in a vehicle in which the driving force is reduced by adjusting the output of the engine when the driving wheels slip, so that appropriate engine output control is performed regardless of the road surface condition. The purpose is to do.

[0007]

That is, according to a first aspect of the present invention, there is provided an engine torque reduction control apparatus for detecting a slip state of a drive wheel as shown in FIG. In a vehicle provided with a detecting means A, the engine output is reduced when the slip state of the driving wheel is detected by the slip detecting means A. When the number of slips counted by the number counting means B and the number of slips equal to or greater than the set number are counted by the counting means B, the engine output is reduced for a predetermined time even when the slip detection means A does not detect the slip state of the drive wheels. A control means C is provided.

An engine torque reduction control device according to a second aspect of the present invention includes a slip detecting means A for detecting a slip state of a driving wheel. In a vehicle in which the engine output is reduced when a wheel slip condition is detected, a slip occurrence frequency counting means B for counting the number of slips of the drive wheel per fixed time is provided as in the first invention. . As shown by the broken line in FIG. 1, a throttle adjusting means D for adjusting the opening degree of a throttle valve provided in the intake system of the engine is provided, and the control means C is controlled by the counting means B to a number of times equal to or greater than a set number. When the slip state is counted, the throttle adjusting means D is operated so that the opening degree of the throttle valve is reduced even when the slip state of the drive wheel is not detected by the slip detecting means A thereafter. The engine is configured to reduce the engine output during the period.

Further, the engine torque-down control device according to claim 3 of the present application (hereinafter referred to as a third invention) includes a slip detecting means A for detecting a slip state of a driving wheel, and is driven by the slip detecting means A. In the vehicle in which the engine output is reduced when the slip state of the wheel is detected, similarly to the second invention, a slip occurrence number counting means B for counting the number of slips of the driving wheel per fixed time is provided. And throttle adjusting means D for adjusting the opening of a throttle valve provided in the intake system of the engine. As shown by a chain line in FIG. 1, a throttle opening detecting means E for detecting the throttle opening is provided, and the control means C is controlled by the counting means B when a slip state of a set number or more is counted. Thereafter, when the throttle opening detected by the throttle opening detecting means E is a high opening equal to or more than a predetermined value, even when the slip state of the driving wheel is not detected by the slip detecting means A, the opening of the throttle valve is maintained. By operating the throttle adjusting means D so as to reduce the engine output, the engine output is reduced for a predetermined time.

An engine torque reduction control device according to a fourth aspect of the present invention (hereinafter referred to as a fourth invention) includes slip detecting means A for detecting a slip state of a driving wheel, and the slip detecting means detects the driving wheel. In the vehicle in which the engine output is reduced when the slip state is detected, a slip occurrence number counting means B for counting the number of slip occurrences of the drive wheel per predetermined time is provided as in the first invention. At the same time, when the slipping state of the driving wheel is not detected by the slip detecting means A when the slip state is counted by the counting means B or more than the set number of times, the control means C is controlled by the engine output reduction amount at the time of slipping. The engine output is reduced by a small amount.

[0011]

In any of the first to fourth aspects of the present invention, when the slip state is detected a predetermined number of times or more per fixed time, the engine output is reduced even when the slip state of the drive wheel is not detected. Therefore, the responsiveness when the next slip occurs is improved.

According to the second aspect of the present invention, when the slip state is detected more than a set number of times per a fixed time, the engine output is reduced by decreasing the throttle opening. , The fuel economy performance is better maintained than when the angle is retarded.

According to the third aspect of the invention, when a slip state equal to or more than a set number of times is detected per fixed time,
At a high opening where the decrease in engine output torque is small with respect to a change in the throttle opening, the throttle opening is reduced in advance and the engine output is reduced. Responsiveness is improved,
Since the amount of decrease in the engine output is small, the driver hardly feels uncomfortable.

Further, according to the fourth aspect of the present invention, since the output reduction amount during the non-slip operation is smaller than that in the normal operation, it is possible to prevent the traveling performance from deteriorating.

[0015]

Embodiments of the present invention will be described below.

As shown in FIG. 2, in the vehicle according to this embodiment, left and right front wheels 1 and 2 are driven wheels, left and right rear wheels 3 and 4 are driving wheels, and the output torque of the engine 5 is reduced. The transmission is transmitted from the transmission 6 to the left and right rear wheels 3 and 4 via the propeller shaft 7, the differential device 8 and the left and right drive shafts 9 and 10.

A main throttle valve 13 connected to an accelerator pedal 12 operated by a driver and a sub-throttle valve 15 connected to a throttle actuator 14 are provided in an intake passage 11 of the engine 5. At the same time, by adjusting the opening of the throttle valves 13 and 15, the intake air amount of the engine 5 is variably controlled, and the engine output is adjusted.

An electronic control unit (hereinafter referred to as an ECU) 16 for performing traction control.
The ECU 16 is provided with signals from wheel speed sensors 17 to 20 for detecting rotation speeds of the wheels 1 to 4 and an engine speed sensor 2 for detecting engine speed.
1 and a signal from a throttle opening sensor 22 for detecting the opening of the main throttle valve 13, and the operation of the throttle actuator 14 is controlled based on these signals. .

Next, the engine output control which is a characteristic part of this embodiment will be described. This engine output control is performed as follows according to the flowchart of FIG.

That is, after reading various data in step S1, the ECU 16 reads the timer value T in step S2.
The After incrementing, the timer value T in step S3 it is determined whether reaches a predetermined setting value T _0, resets the timer value T proceeds to step S4 when it is determined YES, and in step S5 After setting the slip count value n to the slip frequency m, the slip count value n
Is reset, the routine proceeds to step S6, where the basic control amount B of the throttle adjustment actuator 14 is set according to a map in which the throttle opening θ is set as a parameter. The function f (θ) indicating the basic control amount B linearly increases as the throttle opening θ increases, as shown in FIG. 4, for example. Therefore, as the driver depresses the accelerator pedal 12, the basic control amount B increases. When the ECU 16 determines in step S3 that the timer value T has not reached the set value T ₀ ,
The process skips steps S4 and S5 and moves to step S6, where the basic control amount B is set.

Next, the ECU 16 calculates a slip value S in step S7. That is, the ECU 16 calculates the vehicle speed by averaging the left and right rear wheel speeds indicated by the signals from the wheel speed sensors 19 and 20, for example, and calculates the front left wheel speed indicated by the signal from the wheel speed sensor 17 at the vehicle speed. The slip value S is obtained by dividing.

The ECU16 executes the step S8 calculating the slip value S, slip the slip value S is determined whether a predetermined larger slip determination value S _0, in step S9 when it is determined that YES The count value n is incremented, and it is determined in step S10 whether the slip frequency m is greater than a predetermined first set value α. If the slip frequency m does not exceed the first set value α, the process proceeds to step S11. After substituting 0 as the basic reduction amount X of the throttle control amount, a predetermined value Y ₀ is set as the slip reduction amount Y in step S12. Then, in step S13, the final throttle control amount SV is calculated by subtracting the basic decrease amount X and the slip decrease amount Y from the basic control amount B. Then, in step S14, driving is performed such that the final control amount SV is obtained. A signal is output to the throttle actuator 14. In this case, the basic reduction amount X
Therefore, the throttle control amount SV is reduced by the basic reduction amount X.

On the other hand, when the ECU 16 determines in step S10 that the slip frequency m exceeds the first set value α, the ECU 16 proceeds to step S15 and sets the throttle opening θ to a predetermined opening which is previously set to the high opening side. It is determined whether or not the degree exceeds θ ₀ (for example, 開 opening degree), and YES
When the determination is made, step S16 is executed to look up a table of the basic decrease amount in which the slip frequency is previously set as a parameter as shown in FIG. 5, and set a value corresponding to the slip frequency m as the basic decrease amount X. Then, the flag F is set in step S17. The function g (m) indicating the basic decrease amount X is represented by the slip frequency m
The larger the is, the more it increases linearly.

[0024] Also in this case, ECU 16 is adapted to set a predetermined value Y ₀ as the value of the slip reduction amount Y in step S18.

[0025] Then, ECU 16 when it is determined that the slip value S in step S8 does not exceed the slip determination value S _0, the value of the flag F goes to step S19 is to determine whether or not 1, YES and When it is determined, it is determined in step S20 whether the slip frequency m is smaller than the second set value β. Note that the second set value β is set to a value smaller than the first set value α.

When the ECU 16 determines in step S20 that the slip frequency m is not smaller than the second set value β, the ECU 16 immediately executes step S21 to reduce the basic reduction amount X from the basic control amount B set in step S6. The final throttle control amount SV is calculated by subtraction, and a drive signal is output to the throttle actuator 14 so that the final throttle control amount SV is obtained in step S14.

Therefore, the engine output is reduced even when the driving wheels are not slipping.

When the ECU 16 determines in step S20 that the slip frequency m is smaller than the second set value β, the process proceeds to step S22, in which the basic decrease X is reduced by the minute amount δX, and the ECU 16 proceeds to step S23.
It is determined whether or not the basic reduction amount X has become 0, and if the determination is YES, the flag F is reset in step S24.

When the ECU 16 determines in step S19 that the value of the flag F is not 1,
In step S25, 0 is substituted for the basic reduction amount X, and step S21 is executed. Therefore, in this case,
The opening of the sub-throttle valve 15 is adjusted to the opening corresponding to the basic control amount B.

Next, the operation of this embodiment will be described.

That is, as shown in FIG. 6 (b), the slip count value n at the time point t ₁ when the timer value T reaches the set value T ₀ is set to the slip frequency m. when the slip value S as in the figure (a) (a) is as exceeds the slip determination value S ₀ at all times, FIG. (c) slip frequency as shown in (b) m
Is larger than the first set value α. In this case, as in the figure (a) (c), when the slip value S exceeds the slip determination value S ₀ is the figure of (d) (d)
As shown in the figure, the throttle control amount SV is calculated by subtracting the basic reduction amount X and the slip reduction amount Y ₀ from the basic control amount B.
Will be reduced. Further, as shown in (e) in FIG. (A), when the slip value S does not exceed the slip determination value S _0, as shown in (F) in FIG. (D), the base decrease from the basic control amount B The throttle control amount SV is reduced by the amount obtained by subtracting the amount X.

When the slip value S fluctuates near the slip determination value S ₀ as described above, the timer value T
There at the time t ₂ it becomes set value T _0, as shown in the same figure (c) (g), the slip frequency m is smaller than β second set value. In this case, (h) in FIG.
Even if the slip value S does not exceed the slip determination value S ₀ , the basic reduction amount X is controlled so as to gradually converge and converge to 0, as shown in FIG.
, The throttle control amount SV is maintained in a reduced state.

Next, the timer value T is set to the set value T _0.
Is reached at time t ₃ , the slip frequency m becomes 0. However, if the slip value S again exceeds the slip determination value S ₀ before the basic decrease amount X converges to 0, the slip frequency m becomes 0 at that time t ₄ . The throttle control amount SV is reduced by the slip reduction amount Y. Therefore, the engine output is quickly reduced, and the amount of decrease is small, so that the driver does not feel uncomfortable.

[0034] Subsequently explained is another embodiment of the present invention, the engine output control in this embodiment, as shown in the flowchart of FIG. 7, step S16 in the flowchart of FIG. 3 is replaced by Step S ^'16 It can be done.

That is, in this embodiment, FIG.
(A), (b), the map M (N _E, theta) of the basic decrease amount X to the theta engine speed N _E and the throttle opening as parameters is set as the reality of engine The number _NE and the throttle opening θ are applied to the above-described map, and the corresponding basic decrease amount is read. In this case, the map M (N _E , θ)
Is with respect to a boundary of a predetermined rotational speed N ₀ for the engine rotational speed N _E, the basic reduction amount X is in the low rotation side is small, the high-rotation is set to the basic decrease amount X is larger stepwise. Also, the throttle opening θ has a stepped shape in which the basic decrease amount X is small on the low opening side and the basic decrease amount X is large on the high opening side, starting from the predetermined opening θ ₁ having a relatively low opening. Is set. Therefore, the basic reduction amount X that reflects the operating state of the engine is obtained.

If the accuracy does not matter, a constant value may be set as the basic reduction amount X.

[0037]

As described above, according to the present invention, the engine output is reduced even when the slip state of the driving wheels is not detected when the slip state is detected a predetermined number of times or more per a fixed time. Therefore, the responsiveness when the next slip occurs is improved.

According to the second aspect of the present invention, when a slip state is detected more than a set number of times per fixed time, the engine output is reduced by decreasing the throttle opening. , The fuel economy performance is better maintained than when the angle is retarded.

According to the third aspect of the invention, when a slip state equal to or more than a set number of times is detected per a fixed time,
At a high opening where the decrease in engine output torque is small with respect to a change in the throttle opening, the throttle opening is reduced in advance and the engine output is reduced. Responsiveness is improved,
Since the amount of decrease in the engine output is small, the driver hardly feels uncomfortable.

Further, according to the fourth aspect of the invention, since the output reduction amount during the non-slip operation is smaller than that in the normal operation, it is possible to prevent the traveling performance from deteriorating.

[Brief description of the drawings]

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

FIG. 2 is a control system diagram of the vehicle.

FIG. 3 is a flowchart illustrating engine output control.

FIG. 4 is an explanatory diagram showing an example of setting a basic control amount using a throttle opening as a parameter.

FIG. 5 is an explanatory diagram showing an example of setting a basic decrease amount using a slip frequency as a parameter.

FIG. 6 is a time chart showing the operation of the embodiment.

FIG. 7 is a flowchart illustrating engine output control according to another embodiment.

FIG. 8 is an explanatory diagram of a map of a basic decrease amount used in this embodiment.

[Explanation of symbols]

 1, 2 front wheel 3, 4 rear wheel 5 engine 11 intake passage 14 throttle actuator 16 ECU 17-20 wheel speed sensor 22 throttle opening sensor

Claims (4)

(57) [Claims] 1. An engine torque reduction control in a vehicle, comprising: slip detection means for detecting a slip state of a drive wheel, wherein the engine output is reduced when the slip state of the drive wheel is detected by the slip detection means. A slip occurrence count means for counting the number of slip occurrences per fixed time of the drive wheel; and when the slip state is counted by a count equal to or more than a set number, the drive wheel is thereafter detected by the slip detection means. Control means for reducing the engine output for a predetermined time even when the slip state is not detected. 2. A torque reduction control for an engine in a vehicle, comprising: slip detection means for detecting a slip state of a drive wheel, wherein the engine output is reduced when the slip state of the drive wheel is detected by the slip detection means. An apparatus for counting the number of occurrences of slip of the drive wheel per fixed time, a throttle adjusting means for adjusting an opening of a throttle valve provided in an intake system of the engine, and the counting means. When the number of slip states equal to or greater than the set number is counted, the throttle adjusting means is operated so that the opening of the throttle valve is reduced even when the slip state of the drive wheel is not detected by the slip detecting means thereafter. Control means for reducing the engine output for a predetermined time is provided An engine torque reduction control device characterized by the above-mentioned. 3. A torque reduction control of an engine in a vehicle, comprising: slip detection means for detecting a slip state of a drive wheel, wherein the engine output is reduced when the slip state of the drive wheel is detected by the slip detection means. A throttle occurrence number counting means for counting the number of slip occurrences of the drive wheel per fixed time; a throttle adjustment means for adjusting an opening degree of a throttle valve provided in an intake system of the engine; and a throttle opening degree When the throttle opening detected by the throttle opening detecting means is equal to or higher than a predetermined value when the slip state is counted more than a set number of times by the counting means, Thereafter, even when the slip detection means does not detect the slip state of the drive wheels, Control means for reducing the engine output for a predetermined time by operating the throttle adjusting means so as to reduce the opening degree. 4. An engine torque reduction control in a vehicle, comprising: slip detecting means for detecting a slip state of a driving wheel, wherein the engine output is reduced when the slip state of the driving wheel is detected by the slip detecting means. A slip occurrence count means for counting the number of slip occurrences per fixed time of the drive wheel; and a slip state detection means for detecting the slip state of the drive wheel when the count state counts a predetermined number of slips or more. A control means for reducing the engine output by an amount smaller than the engine output decrease amount during the slip for a predetermined time when a slip state is not detected.