JP3323219B2 - Vehicle slip 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 a vehicle slip control device.

[0002]

2. Description of the Related Art A vehicle slip control (traction control) device detects a slip amount of a driving wheel in order to prevent the driving wheel from slipping due to an excessive driving torque and deteriorating the acceleration during vehicle acceleration. It is generally known that engine control for reducing the engine output and brake control for controlling the braking force of the drive wheels are performed so that the slip amount of the drive wheels becomes the target slip amount.

[0003] For example, Japanese Patent Application Laid-Open No. 64-106762 discloses a control variable calculating means for calculating a control variable corresponding to a slip amount of a driving wheel from a wheel speed, and a traction control for performing a brake control based on the control variable. In a control system, a proposal is described in which, when using the above control variables, a filter is applied to the control variables in accordance with the degree of unevenness of the road surface to prevent vehicle body vibration and pitching on rough roads.

[0004]

By the way, in the slip control of a vehicle, the brake control amount and the engine control amount are determined not only based on the slip amount of the drive wheel but also in consideration of the acceleration of the drive wheel. By doing so, control according to the tendency of the increase or decrease of the slip amount can be performed, which is advantageous in terms of early convergence of the slip.

However, when the vehicle is running at high speed, a periodic load acts on the wheels due to the resonance of the suspension, and the acceleration of the driving wheels may fluctuate. On the other hand, if the acceleration of the driving wheels is used as it is for the calculation of the control amount as described above, the braking force fluctuates due to the fluctuation of the acceleration, and the driving wheels vibrate and the vibration of the suspension As a result, vibration of the vehicle body may be caused.

That is, it is an object of the present invention to efficiently suppress the slip of the drive wheels during acceleration of the vehicle without promoting the vibration of the suspension, and to improve the acceleration.

[0007]

SUMMARY OF THE INVENTION The present invention provides
In order to solve this problem, the calculation of the engine control amount takes into account the actual acceleration of the drive wheels, and the calculation of the brake control amount takes into account the smoothed value obtained by filtering the actual acceleration of the drive wheels. Is what you can do.

That is, means for solving the above problems include an engine control means for reducing the engine output so that the slip amount of the drive wheel with respect to the road surface at the time of acceleration of the vehicle becomes a target value; Brake control means for controlling a braking force applied to the drive wheel so that the amount becomes a target value, and the engine control means and the brake control means include control amount calculation means for calculating respective control amounts. A slip control device for the vehicle, wherein a slip amount detecting means for detecting the slip amount of the drive wheel, a means for calculating a deviation between the slip amount and a target value of the engine control means as an engine control amount calculation variable , Means for calculating a deviation between the slip amount and a target value of the brake control means as a brake control amount calculation variable ;
Means for determining the time rate of change of the engine control amount calculating variables, means and a predetermined percentage of the previous value to the time rate of change of the sought brake control amount calculation variables for determining the time rate of change of the brake control amount calculation variables Filter means for obtaining a smoothed time change rate reflected by the control means, wherein the control amount calculation means of the engine control means calculates a control amount based on the engine control amount calculation variable and its time change rate, The control amount calculating means of the brake control means calculates the brake control amount
When the change amount of the time change rate of the operation variable is equal to or less than a predetermined value
Based on the said brake control amount calculation variables and the time between the change rate
The control amount is calculated and the change amount exceeds a predetermined value.
To the variable for calculating the brake control amount and the filter means.
Thus, the control amount is calculated based on the smoothing time change rate obtained .

In such a means for solving the problem, even if the acceleration of the drive wheels fluctuates due to suspension resonance, the calculation of the brake control amount requires a smoothing value ( brake control amount) in which the influence of the fluctuation is reduced. Arithmetic variable averaging time
Change rate ) can be used, and it is possible to prevent the vibration of the suspension from being promoted by an excessive change in the braking force.

On the other hand, since the engine control amount is calculated not by the smoothed value but by the time rate of change of the engine control amount calculation variable including the actual acceleration component of the drive wheel, the control response delay is increased. Can be prevented. In other words, if the smoothed value is used for calculating the engine control amount, the time change rate is filtered when the acceleration of the drive wheels actually increases, that is, when the slip amount tends to increase. for, although so that control is delayed, as described above Fi
Since the engine control amount is calculated using the time rate of change without filtering, there is no control delay. Also, be calculated in this way on the basis of the engine control amount to the time the filter is not applied the change rate, increase or decrease of the engine output is not given a direct effect on the vibrations of the suspension, the promotion of the vibration No problem.

When the wheel speed of the drive wheel increases due to depression of the accelerator pedal and the slip amount increases, engine control and brake control are executed to suppress the increase in the slip amount and the wheel speed slows down. . At this time, while the wheel speed of the drive wheel reaches its peak, the acceleration of the drive wheel greatly changes from a positive value to a negative value, and at this time, the influence of the suspension resonance affects the acceleration. When it appears, the amount of change in the acceleration becomes very large. If such a large change in the acceleration is directly reflected in the brake control amount, the change in the braking force becomes excessively large.

[0012] For this, when the control amount calculation of the brake control means, when the change amount of the time rate of change is less than a predetermined value using the time rate of change in the calculation of the control amount, the change amount is the predetermined value so that use of the above moderated value when exceeding.

In this manner, in a region where the change in acceleration before the wheel speed of the drive wheel reaches a peak is small,
Although will be used <br/> time rate of change filter is not applied to the operation of the brake control amount, no significant variation in the braking force from the change in the time rate of change is small, rather immediately to changes in acceleration With the brake control performed, early convergence of the slip of the drive wheels can be achieved. On the other hand, in a region where the change in acceleration before and after the peak of the wheel speed is large, the smoothed value is used in the calculation of the brake control amount, so that even if the change in acceleration is large, excessive fluctuation of the braking force is prevented. This can prevent the suspension from vibrating. Also, at this time, since the slip of the drive wheels is beginning to show a tendency to converge, there is little problem even if the brake control is delayed with respect to the actual change in acceleration.

In calculating the smoothed value, the above
It is preferable that the larger the change amount of the inter-change rate is, the larger the ratio of the previous value reflected on the current detection value is.

With this arrangement, when the vibration of the suspension is more likely to be promoted, the degree of smoothing of the acceleration is increased and the fluctuation of the braking force is reduced, which is advantageous in preventing the vibration of the suspension from being promoted. .

[0016]

Therefore, according to the present invention, the calculation of the engine control amount takes into account the time rate of change of the engine control amount calculation variable including the acceleration component of the drive wheels, while the calculation of the brake control amount is performed. Filter means for obtaining a smoothed value by reflecting the previous value at a predetermined rate to the time change rate of the brake control amount calculation variable;
When the amount of change in the change rate is equal to or less than a predetermined value, the time change rate
Is used to calculate the brake control amount, and the change amount
If it exceeds, use the above smoothed value to calculate the brake control amount.
Since the control response delay to the actual fluctuation of the driving wheel acceleration is prevented on the engine control side, the acceleration of the driving wheel is reduced due to the resonance of the suspension.
Be varied greatly, the vibration of the suspension by suppressing excessive fluctuations of the brake control amount, can be prevented and hence the vehicle body vibration is promoted. Further, when the slip amount of the drive wheel tends to increase the response delay of With no brake control, the convergence of the slip of the drive wheels can be achieved early.

In calculating the smoothed value, the greater the change in the acceleration or the rate of change in time, the greater the proportion of the previous value reflected on the current detected value. Can be efficiently prevented.

[0018]

1 is a front left wheel, 1FR is a front right wheel, 1RL is a rear left wheel, and 1RR is a rear right wheel. An engine 2 is mounted horizontally on the front of the vehicle body. The torque generated by the engine 2 is transmitted to a clutch 3, a transmission 4, and a differential gear 5, and then transmitted to a left front wheel 1FL via a left drive shaft 6L. And via the right drive shaft 6R to the right front wheel 1FR. As described above, the vehicle has the front wheels 1F
L, 1FR are drive wheels, and rear wheels 1RL, 1RR are front wheel drive vehicles that are driven wheels.

Brake 7FL to 7R mounted on each wheel
R is a hydraulic disc brake.
Also, a master cylinder 8 as a brake fluid pressure generation source
Is a tandem type having two discharge ports 8a and 8b. A brake pipe 13 extending from one discharge port 8a of the master cylinder 8 is branched into two on the way.
The branch pipe 13F is connected to (the wheel cylinder mounted in the caliper of) the left front wheel brake 7FL, and the branch pipe 13R is connected to the right rear wheel brake 7RR.
The branch pipe 14 extending from the other discharge port 8b of the master cylinder 8 is also branched into two, the branch pipe 14F is connected to the right front wheel brake 7FR, and the branch pipe 14R is connected to the left rear wheel brake 7RL. .

Branch pipe 13 for front wheels, that is, for drive wheels
F and 14F are provided with an electromagnetic hydraulic pressure control valve 15L or 1F.
5R is connected, and an electromagnetic on-off valve 16L or 16R is connected to the rear wheel branch pipes 13R and 14R. The hydraulic pressure adjusting valves 15L and 15R are provided with a brake 7FL,
The brake fluid pressure from the master cylinder 8 to the 7FR and the brake fluid pressure of the brakes 7FL and 7FR are
The mode is switched between release to the reservoir tanks 22L and 22R via 1L and 21R. The brake fluid in the reservoir tank 21L is returned to the pipe 13 by a pump 23L via a pipe 25L to which a check valve 24L is connected. Similarly, the brake fluid in the reservoir tank 22R is returned to the pump 23L.
By R, it is returned to the pipe 14 via the pipe 25R to which the check valve 24R is connected.

The depression force on the brake pedal 12 is
The power is transmitted to the master cylinder 8 via a booster, that is, a brake booster 11. This booster 11 is basically the same as a known vacuum booster. However, in the case of slip control, as described later, it is possible to obtain a braking force even when the brake pedal is not depressed. It is configured to be able to.

The booster 11 has a case 31 fixed to the vehicle body and the master cylinder 8, and the inside of the case 31 is divided into a first chamber 34 and a second chamber 34 by a diaphragm 32 and a valve body 33 fixed thereto. 35. The negative pressure of the negative pressure source (for example, the negative pressure of the intake air of the engine 2) is always supplied to the first chamber 34, and when the brake pedal is not depressed, the second chamber 35 becomes the first chamber 3
4, and the operation of the booster 11 is stopped. Then, when the brake pedal 12 is depressed, atmospheric pressure is supplied to the second chamber 35, whereby the diaphragm 32 is displaced forward together with the valve body 33, and a boosting action is obtained.

Switching between the negative pressure supply and the atmospheric pressure supply to the second chamber 35 is basically performed by a valve device provided in the valve body 33. This valve body 33
The portion will be described with reference to FIG.

First, the valve body 33 has a power piston 41 fixed to the diaphragm 32. In a recess 41a formed in the power piston 41, a reaction disk 42 and a base end of an output shaft 43 are formed. Mated. This output shaft 43 serves as an input shaft of the master cylinder 8. A valve plunger 45 is mounted in the valve body 33 at the tip of the input shaft 44 connected to the brake pedal 12. Behind the valve plunger 45, a vacuum valve 46 is provided.

A pressure introduction passage 50 is provided in the power piston 41.
The pressure introducing passage 50 is always in communication with a space X formed around the valve plunger 45. This space X is always in communication with the second chamber 35. A valve seat 47 on which the vacuum valve 46 is detached and seated is formed at an opening end of the pressure introducing passage 50 on the space X side. Further, the vacuum valve 46 includes a valve plunger 45.
The seat is also detached from and seated on a valve seat 45a formed at the rear end.

In the above configuration, it is assumed that a negative pressure is introduced into the pressure introducing passage 50. In this state, when the brake pedal 12 is not depressed, the vacuum valve 46 is seated on the valve seat 45a by the urging force of the springs 48 and 49 in the state of FIG. I have. Therefore, the pressure introduction passage 5
The negative pressure from 0 is introduced into the second chamber 35 via the space X, and no boosting action is performed.

When the brake pedal 12 is depressed,
The input shaft 44 and thus the valve plunger 45 are moved forward (to the left in the drawing). During this forward movement, the vacuum valve 46
Is first seated on the valve seat 47 and the space X and the pressure introduction passage 50 are
To the vacuum valve 46 and the valve seat 45
a are separated. When the vacuum valve 46 and the valve seat 45a are separated from each other, the atmospheric pressure from behind the valve body 33 is introduced into the space X, and the second chamber 35 becomes the atmospheric pressure. As a result, the diaphragm 32 is displaced forward together with the valve body 33, and as a result, the output shaft 43 moves forward and a boosting action is performed. The brake reaction force from the master cylinder 8 is transmitted via the reaction disk 42 to the valve plunger 45 and thus to the brake pedal 12.
When the depressing operation force of the brake pedal 12 is released, the state is returned to the state of FIG. 2 by the return spring 36 (see FIG. 1), and the vehicle is prepared for the next boosting action.

Although the parts described above are the same as those of the known vacuum booster, in the present embodiment, the negative pressure of the first chamber 34 is introduced into the pressure introduction passage 50 for slip control. The state is switched to a state in which atmospheric pressure is introduced. That is, the first chamber 34 and the pressure introduction passage 5
0 is connected via a pipe 37, and a three-way electromagnetic switching valve (introduction switching means) 38 is connected to the pipe 37 (FIG. 1).
reference). The switching valve 38 is connected to the pressure introducing passage 50 during demagnetization.
Is communicated with the first chamber 34, and the atmospheric pressure is introduced into the pressure introducing passage 50 at the time of excitation. When the switching valve 38 is excited and the atmospheric pressure is introduced into the pressure introducing passage 50, the space X, and thus the second chamber 35, becomes the atmospheric pressure even if the brake pedal 12 is not depressed. By performing the boosting operation, the brake fluid pressure is generated in the master cylinder 8.

Next, the control system will be described.

The control system is constituted by using a microcomputer. In FIG. 1, reference numeral 51 denotes control means for performing engine control and brake control, and the control means 51 includes control means for each of the wheels 1FL to 1RR. Signals from the sensors S1 to S4 for detecting the rotation speed are input.

The control means 51 includes a friction coefficient detecting means for detecting a friction coefficient of the road surface, a control target value setting means, a slip amount detecting means 52, a DEN calculating means 53, a filtering means 54, an engine control amount calculating means 55, a brake. The control means 51 includes a control amount calculating means 56, a slip judging means, and an output means for controlling the engine output and the brake. The control means 51 includes an engine output adjusting means 9 for controlling the engine and a fluid for controlling the brake. Control signals are output to the pressure regulating valves 15L and 15R, the on-off valves 16L and 16R, and the switching valve 38. Engine output adjusting means 9
Is for adjusting the engine output by driving a sub-throttle valve (not shown) provided in the intake passage separately from the main throttle valve linked to the accelerator pedal 10.

Hereinafter, a specific description will be given.

[Detection of Road Surface Friction Coefficient] The friction coefficient detection means detects the friction coefficient of the right and left road surfaces on which the left and right drive wheels 1FL and 1FR roll, and the detection is performed by the corresponding left and right driving wheels 1FL and 1FR. Driven wheel 1RL, 1RR
Is performed based on the wheel speed Vr and the acceleration VG.

First, a timer A is used to calculate the acceleration VG.
(100 msec count) and timer B (500 msec count). That is, the acceleration VG is the wheel speed Vr for 100 msec every 100 msec until 500 msec elapses after the start of the slip control (the acceleration is not sufficiently large).
(Unit: km / h) is calculated by the following equation (1), and after 500 msec (acceleration is sufficiently developed), 100
Based on the change in wheel speed Vr for 500 msec every msec,
It is calculated by equation (2).

− (1) Equation−VG = Gk1 × ｛Vr (k) −Vr (k−100)｝ − (2) Equation−VG = Gk2 × ｛Vr (k) −Vr (k−500)｝ Gk1 and Gk2 are coefficients. Vr (k) is at the present time, Vr (k-100) is 100 msec before, and Vr (k-500) is 50 msec.
These are the wheel speeds before 0 msec.

From the acceleration VG and the wheel speed Vr calculated as described above, the road surface friction coefficient μ is obtained by three-dimensional interpolation according to the following Table 1. When the slip control is not being performed, the friction coefficient μ is set to 3.0.

[0037]

[Table 1]

[Setting of Control Target Value] The control target value is a target value as the slip amount of the front wheels 1FL and 1FR, and is determined by the wheel speed Vr and the friction coefficient μ.
It is calculated based on That is, the engine control target value SET is determined based on the wheel speed Vr and the friction coefficient μ of the faster one of the left and right driven wheels 1RL and 1RR so that the value decreases as the wheel speed Vr increases. In addition, the calculation is performed from a map set such that the value decreases as the friction coefficient μ decreases. In calculating the brake control target value SBT, a map set to a value higher than the engine control target value is used.

[Slip Amount Detection] The slip amount detection means 52 includes left and right driving wheels 1FL, 1FR.
By subtracting the faster one of the left and right driven wheels 1RL, 1RR from the wheel speeds VFL, VFR, the slip amounts SL, SR of these two wheels are obtained.

Further, as shown in the following equation, an average slip amount SAv is obtained based on the slip amounts SL and SR, and a deviation of the SAv from the engine control target value SET is calculated as an engine control amount calculation variable EN. I do.

EN = (SL + SR) / 2-SET On the other hand, in order to calculate the brake control amount, the deviation of SL and SR from the brake control target value SBT is calculated as a calculation variable EN as shown by the following equation. .

EN = SL-SBT EN = SR-SBT In the brake control, the left and right driving wheels 1FL, 1FR
In order to independently control the braking force applied to the drive wheels 1EN, EN is obtained for each of the drive wheels 1FL and 1FR.

[DEN Calculation] The DEN calculation means 53 calculates the time change rate DEN of the calculation variable EN of each of the engine control amount and the brake control amount. This DEN reflects the driving wheel acceleration
Have been. That is, the DEN includes 1FL, 1F
The differential terms of the wheel speeds VFL and VFR of R are included.

[Filter Means] The filter means 54 obtains an annealed value by reflecting the previous value in the DEN calculated by the DEN calculating means 53 at a predetermined rate . Specifically, the current detection value D
A smoothed DEN is obtained by exponential smoothing of the following equation in which the previous output value DEN (k-1) is reflected on EN (k) by a predetermined ratio TE.

Smoothing DEN = DEN (k) × (1−TE) + DEN (k−1) × TE [Engine control amount calculation] The engine control amount calculation means 55 is a drive detected by the slip amount detection means 52. Wheel slip SL, S
An operation variable EN for an engine control amount based on the average value of R;
Using the time change rate DEN of the EN as a parameter, it is obtained from the following map (Table 2).

[0046]

[Table 2]

In this case, the symbol ZO described in the above-mentioned map indicates that the opening degree of the sub-throttle valve is maintained, N indicates closing, P
Represents opening movement. The subscripts S, M, and B of N and P indicate the magnitude of the control amount, where "S" is small (small opening and closing amounts) and "M" is medium (medium opening amount and closing amount). Middle), "B" means large (large open and close movements).

[Calculation of Brake Control Amount] The brake control amount calculating means 56 calculates, for each driving wheel, each calculation variable EN for the brake control amount based on the respective slip amounts SL and SR detected by the slip amount detecting means 52. And the time change rate DEN of the EN as a parameter, and is obtained from a map (not shown) basically set in the same tendency as that shown in Table 2 above.

However, regarding the time change rate DEN,
The DEN obtained by the DEN calculation means 53 and the smooth DEN obtained by the filter means 54 are selectively used.

That is, the brake control amount calculating means 56
When the absolute value の of the DEN change amount ΔDEN ｛DEN (k) −DEN (k−1) obtained by the DEN calculation means 53 is equal to or smaller than a predetermined value Ko, the DEN (k) is calculated as a control amount. When the change amount ΔDEN exceeds a predetermined value Ko, the above-mentioned smoothed DEN is used.

Further, the brake control amount calculating means 56
Is provided with means for changing and setting the reflection ratio TE of the previous value in the filter means 54 based on the change amount ΔDEN. In this case, the setting is made such that the TE increases as the ΔDEN increases.

FIG. 3 shows the flow of the above-described brake control amount calculation. First, when various data are input and the brake control is being performed, the calculation of the brake control amount is executed (steps P1 and P2). That is, the change amount Δ
If DEN is equal to or less than Ko, a brake control amount is calculated using the current detection value DEN (k) (steps P3 to P3).
5). On the other hand, when the variation .DELTA.DEN exceeds Ko, the reflection ratio TE of the previous value in the filter means 54 is determined based on the variation .DELTA.DEN, and a smoothed DEN is determined using the TE, and the smoothed DEN is determined. Is used to calculate the brake control amount (steps P3 → P6 → P
7 → P5).

[Slip Judgment] When the larger one of the slip amounts SL and SR of the drive wheels becomes equal to or more than the engine control target value SET, it is judged that the engine control is necessary. It is determined that the brake control is necessary when the value exceeds the target value SBT.

[Output Control] The engine control is executed by driving the sub-throttle valve with the control amount obtained by the engine control amount calculating means 55, and the brake control is performed by the brake control amount calculating means 56. A control signal corresponding to the control amount obtained for each drive wheel is transmitted to the hydraulic pressure adjusting valve 15L, 1
This is performed by outputting to 5R (duty control).

[Example of Slip Control] FIG. 4 shows an example of slip control. That is, before the time t1, since no large slip has occurred in the drive wheels, the engine control is not performed, so that the sub throttle valve is fully opened and the throttle opening Tn
(This is the combined opening of both the main and sub throttle valves, and matches the opening of the smaller opening of the throttle valve.)
Is the opening TH · M of the main throttle valve corresponding to the accelerator pedal depression amount.

At time t1, a large slip occurs when the slip amount of the drive wheel has reached the engine control target value SET. At time t1, the throttle opening is reduced at once to a preset lower limit control value SM (feed forward control). Then, once the SM is set, the opening of the sub-throttle valve is controlled so that the slip amount of the drive wheel becomes the engine control target value SET. At this time,
The throttle opening Tn is the sub-throttle valve opening TH · S.

At the time point t2, the slip amount of the drive wheel becomes equal to or more than the brake control target value SBT. In this case, the brake fluid pressure is supplied to the drive wheel, and both the engine control and the brake control are performed. Slip control is started. The brake fluid pressure is controlled so that the slip amount of the drive wheel becomes equal to the brake control target value SBT.

At the time point t3, the slip amount of the drive wheels becomes smaller than the brake control target value SBT, whereby the brake fluid pressure is gradually reduced, and eventually the brake fluid pressure becomes zero. However, engine control is still continued. In the embodiment, the condition for terminating the engine control is a time when the slip amount converges on the SET.

[Regarding Effect of Resonance of Vehicle Suspension] In FIG. 5, a curve indicated by a solid line indicates the wheel speed and acceleration of the drive wheel when there is no effect of resonance of the vehicle suspension, and a curve indicated by a broken line indicates FIG. 3 is a model diagram showing a case where a periodic load acts on a driving wheel due to the resonance of a suspension and the acceleration of the driving wheel fluctuates.

That is, as shown by the solid line, when the wheel speed of the drive wheels accelerates due to the depression of the accelerator pedal 10 and the slip amount increases, the above-described engine control and brake control are executed to suppress the increase in the slip amount. And
Wheel speed peaks after a slow rise and then decreases. On the other hand, the acceleration of the drive wheel peaks in the process of increasing the wheel speed, and then greatly changes from a positive value to a negative value when the wheel speed reaches the peak. The actual acceleration is as indicated by the broken line, with the fluctuation due to suspension resonance added to the solid line.

As can be seen from the figure, the amount of change in acceleration ΔG is small until the wheel speed steadily increases, even if there is the effect of suspension resonance. The quantity ΔG becomes very large. The acceleration corresponds to DEN for calculating the brake control amount, and ΔG corresponds to the change amount ΔDEN.

In this embodiment, the predetermined value Ko is:
When the change ΔG of the acceleration before the wheel speed of the drive wheel reaches the peak is small, the brake control amount is calculated using DEN, and when the change ΔG of the acceleration before and after exceeding the peak is large, the smoothing DEN is used. Thus, the brake control amount is calculated. Therefore, ΔDEN
Is smaller than or equal to the predetermined value Ko, the brake control amount is calculated using the DEN obtained by the DEN calculating means 53. Therefore, in FIG. 5, until the wheel speed reaches a peak,
The brake control amount is calculated according to the actual acceleration. At this time, since the change amount of the acceleration is small, there is no large change in the braking force, and rather, the convergence of the slip of the drive wheel can be achieved early by the brake control according to the change of the acceleration.

On the other hand, in the region where the change in acceleration before and after the wheel speed exceeds the peak is large, the smooth DEN is used in the calculation of the brake control amount. Is prevented. Therefore, it is possible to prevent the vibration of the suspension from being promoted, and at this time, since the slip of the drive wheels is beginning to show a tendency to converge, the brake control may be delayed with respect to the fluctuation of the actual acceleration. Even if there is, there is little trouble. Further, as described above, the brake control
Even if the control is performed based on EN, the engine control is performed with good responsiveness based on DEN corresponding to the actual acceleration, so that there is little trouble in terms of slip convergence.

The acceleration change ΔG (ΔDE
When N) increases, the reflection ratio TE of the previous value for obtaining the smoothed DEN increases accordingly. As a result, the fluctuation of the braking force decreases, which is advantageous in preventing the vibration of the suspension from being promoted. Become.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate embodiments of the present invention.

FIG. 1 is an overall configuration diagram of a vehicle slip control device.

FIG. 2 is a sectional view of a brake booster.

FIG. 3 is a flowchart of a brake control amount calculation.

FIG. 4 is a diagram showing an example of a temporal change in a slip amount of a drive wheel or the like in slip control.

FIG. 5 is a diagram showing the effect of suspension resonance on drive wheel acceleration.

[Explanation of symbols]

 1FL, 1FR Driving wheel 2 Engine 7FL to 7FR Brake 9 Engine output adjustment means 51 Control means 52 Slip amount detection means 53 DEN calculation means 54 Filter means 55 Engine control amount calculation means 56 Brake control amount calculation means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60T 8/58

Claims (2)

(57) [Claims] An engine control means for reducing the engine output so that the slip amount of the drive wheel with respect to the road surface at the time of acceleration of the vehicle becomes a target value, and the slip amount of the drive wheel with respect to the road surface becomes the target value. A brake control means for controlling a braking force applied to the drive wheel, wherein the engine control means and the brake control means include control amount calculation means for calculating respective control amounts. A slip amount detecting means for detecting a slip amount of the drive wheel; a means for calculating a deviation between the slip amount and a target value of the engine control means as an engine control amount calculation variable ; Means for calculating a deviation from a target value as a brake control amount calculation variable , and means for calculating a time change rate of the engine control amount calculation variable When, the brake control amount and the means for determining the time rate of change of the operational variables, the sought brake control amount to the time rate of change of the operational variables to reflect the previous value at a predetermined rate to obtain a smoothing time change rate filter means with the door, the control amount calculation means of the engine control means calculates a control amount based on the engine control amount calculating variables and its time rate of change, the control amount calculation means of the brake control means, said brake
The change amount of the time change rate of the control amount calculation variable is less than a predetermined value.
Sometimes the brake control amount calculation variable and its time change rate
And the control amount is calculated based on
The brake control amount calculation variable and the above
A vehicle slip control device for calculating a control amount based on a smoothing time change rate obtained by a control means. 2. A control amount calculating means according to claim 1, wherein said control amount calculating means of said brake control means increases a reflection ratio of a previous value in said filter means as a change amount of said time change rate of said brake control amount calculating variable increases. Vehicle slip control device.