JPH05201324A - Slip controller for vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] Efficiently suppress slipping of the drive wheels during acceleration of the vehicle without promoting vibration of the suspension.
To improve its acceleration. The engine control amount is calculated by using the slip amount of the driving wheel detected by the slip amount detection means 52 and the acceleration detected by the acceleration detection means 53, while the calculation of the brake control amount is performed. A filter means 54 is provided to obtain the smoothed acceleration by reflecting the previous value at a predetermined rate on the acceleration detected by the acceleration detecting means 52, and the brake controlled amount is calculated using the smoothed acceleration as needed.

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 drive wheel in order to prevent the drive wheel from slipping due to an excessive drive torque during acceleration of the vehicle to deteriorate acceleration performance. It is generally known that the engine control for reducing the engine output and the 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.

For example, in Japanese Patent Laid-Open No. 64-106762, there is provided a control variable calculating means for calculating a control variable corresponding to the slip amount of the driving wheel from the wheel speed, and traction for performing brake control based on the control variable. In the control system, when using the above control variable, a proposal is proposed to prevent the vehicle body vibration and pitching during rough road traveling by applying a filter according to the degree of unevenness of the traveling road surface to the control variable.

[0004]

By the way, in the slip control of the vehicle, not only the brake control amount and the engine control amount are obtained based on only the slip amount of the driving wheel, but also the acceleration of the driving wheel is taken into consideration. In this case, the control can be performed according to the tendency of the increase / decrease of the slip amount, which is advantageous in the early convergence of slip.

However, when the vehicle is traveling at a high speed, a cyclic load may be applied to the wheels due to the resonance of the suspension, and the acceleration of the drive wheels may fluctuate. On the other hand, if the acceleration of the driving wheel 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 therefore the driving wheel vibrates and the suspension vibrates. As a result, the vehicle body may be vibrated.

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

[0007]

Means for Solving the Problem and Its Action The present invention is
To solve such a problem, the actual acceleration of the drive wheels is used for the calculation of the engine control amount, and the smoothed acceleration obtained by filtering the actual acceleration of the drive wheels is used for the calculation of the brake control amount. It can be used.

That is, means for solving the above problems are engine control means for reducing the engine output so that the slip amount of the drive wheels on the road surface during acceleration of the vehicle becomes a target value, and slip of the drive wheels on the road surface. And a 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 adjust the slip amount of the drive wheel and the acceleration of the drive wheel. A slip control device for a vehicle, comprising: a control amount calculating means for calculating each control amount based on a slip amount detecting means for detecting a slip amount of the driving wheel; and an acceleration for detecting an acceleration of the driving wheel. A detection means, and a filter means for obtaining a smoothed acceleration by reflecting the previous value at a predetermined ratio on the acceleration detected by the acceleration detection means. The engine control means includes a control amount calculation means for calculating a control amount based on a slip amount of the driving wheel detected by the slip amount detection means and an acceleration detected by the acceleration detection means, and the brake amount. The control amount calculation means of the control means is selected from the slip amount of the drive wheel detected by the slip amount detection means, the acceleration detected by the acceleration detection means, and the smoothed acceleration obtained by the filter means. The control amount is calculated based on the acceleration.

In such means for solving the problem, even if the acceleration of the driving wheel fluctuates due to the resonance of the suspension, the smoothed acceleration that reduces the influence of this fluctuation is used in the calculation of the brake control amount. Therefore, it is possible to prevent the vibration of the suspension from being promoted by the excessive fluctuation of the braking force.

On the other hand, since the actual acceleration of the driving wheels is used for the calculation of the engine control amount, not the above-mentioned smoothed acceleration, it is possible to prevent the control response delay. In other words, if the smoothed acceleration is used to calculate the engine control amount, the acceleration is filtered when the acceleration of the driving wheels actually increases, that is, the slip amount tends to increase. Although the control is delayed, the control delay is eliminated because the engine control amount is calculated using the actual acceleration as described above. Further, even if the engine control amount is calculated based on the actual acceleration in this way, the increase or decrease in the engine output does not directly affect the vibration of the suspension, and there is no problem of promoting this vibration.

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

On the other hand, in calculating the control amount of the brake control means, when the amount of change in the acceleration detected by the acceleration detecting means is less than a predetermined value, the detected acceleration is used for calculating the control amount, and the change is calculated. When the amount is equal to or more than a predetermined value, it is preferable to use the above-mentioned smoothing acceleration.

In this way, in a region where the change in acceleration before the wheel speed of the drive wheel reaches its peak is small,
Although the actual acceleration is used to calculate the brake control amount, since the change in acceleration is small, there is no large change in the braking force. Instead, the brake control that matches the change in acceleration is used to achieve early convergence of the slip of the drive wheels. You can On the other hand, in the region where the change in acceleration before and after the peak of the wheel speed is large, the accelerating acceleration is used in the calculation of the brake control amount, so that the excessive fluctuation of the braking force is prevented even if the acceleration change is large. Therefore, the vibration acceleration of the suspension can be prevented. Further, since the slip of the drive wheels is beginning to converge at this time, there is little trouble even if the brake control is delayed with respect to the actual fluctuation of the acceleration.

In calculating the smoothed acceleration, it is preferable that the larger the amount of change in the acceleration detected by the acceleration detecting means, the larger the ratio of the previous value reflected in the detected value this time.

With this configuration, when the tendency of promoting the vibration of the suspension is large, the degree of acceleration is increased to reduce the fluctuation of the braking force, which is advantageous in preventing the vibration promotion of the suspension. ..

[0016]

Therefore, according to the present invention, the slip amount of the driving wheel detected by the slip amount detecting means and the acceleration detected by the acceleration detecting means are used for the calculation of the engine control amount, while the brake is applied. In order to calculate the control amount, a filter means is provided to obtain the smoothed acceleration by reflecting the previous value in a predetermined ratio to the acceleration detected by the acceleration detecting means, and the brake is braked using the smoothed acceleration as necessary. Since the control amount is calculated, the brake control can be performed even if the drive wheel acceleration fluctuates due to suspension resonance while preventing the engine control side from delaying the control response to the actual fluctuation of the drive wheel acceleration. It is possible to suppress excessive fluctuations in the amount and to prevent the vibration of the suspension and the vibration of the vehicle body from being promoted.

Further, in the calculation of the brake control amount, when the change amount of the acceleration detected by the acceleration detecting means is less than a predetermined value, the detected acceleration is used for the calculation of the control amount, and the change amount is equal to or more than the predetermined value. According to the one using the above-described smoothed acceleration, when the slip amount of the driving wheels tends to increase, the slip control of the driving wheels is quickly converged by the brake control without a response delay,
When there is a large change in the acceleration of the driving wheels, use of the above-mentioned smoothed acceleration prevents excessive fluctuations in the braking force,
Vibration promotion of the suspension can be prevented.

In the calculation of the smoothed acceleration, the larger the change amount of the acceleration detected by the acceleration detecting means, the larger the ratio of the previous value reflected in the detected value this time is. It is possible to efficiently prevent the vibration promotion of.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 1FL is a left front wheel, 1FR is a right front wheel, 1RL is a left rear wheel, and 1RR is a right rear wheel. The engine 2 is mounted horizontally on the front part of the vehicle body, and the torque generated by the engine 2 is transmitted to the clutch 3, the transmission 4, and the differential gear 5, and then the left front wheel 1FL is passed through the left drive shaft 6L. To the right front wheel 1FR via the right drive shaft 6R. In this way, the vehicle has front wheels 1F.
L and 1FR are the driving wheels, and the rear wheels 1RL and 1RR are the driven wheels, which are the driven wheels.

Brake 7FL to 7R mounted on each wheel
R is a hydraulic disc brake.
In addition, the master cylinder 8 as a brake fluid pressure generation source
Is a tandem type having two discharge ports 8a and 8b. The brake pipe 13 extending from one discharge port 8a of the master cylinder 8 is branched into two in the middle,
The branch pipe 13F is connected to the left front wheel brake 7FL (the wheel cylinder mounted inside the caliper), 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
Electromagnetic hydraulic pressure adjusting valve 15L or 1 is provided on F and 14F.
5R is connected, and an electromagnetic opening / closing valve 16L or 16R is connected to the branch pipes 13R and 14R for the rear wheels. The hydraulic pressure adjusting valves 15L and 15R are the brake 7FL,
The brake fluid pressure supply from the master cylinder 8 to the 7FR and the brake fluid pressure of the brakes 7FL and 7FR are connected to the pipe 2
The mode of switching to the reservoir tanks 22L and 22R via 1L and 21R is switched. The brake fluid in the reservoir tank 21L is returned to the pipe 13 by the pump 23L via the pipe 25L to which the check valve 24L is connected. Similarly, the brake fluid in the reservoir tank 22R is pumped by the pump 23L.
By R, the check valve 24R is returned to the pipe 14 via the pipe 25R to which the check valve 24R is connected.

The stepping force on the brake pedal 12 is
It is transmitted to the master cylinder 8 via a booster or brake booster 11. This booster 11 is basically the same as a known vacuum booster, but when performing slip control, as will be 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 inside the case 31, a first chamber 34 and a second chamber are formed by a diaphragm 32 and a valve body 33 fixed to the diaphragm 32. 35. The negative pressure of the negative pressure source (for example, the intake negative pressure of the engine 2) is always supplied to the first chamber 34, and the second chamber 35 is the first chamber 3 when the brake pedal is not depressed.
4 is communicated with the booster 11 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.

The switching between the negative pressure supply and the atmospheric pressure supply to the second chamber 35 is basically performed by a valve device mounted inside the valve body 33. This valve body 33
The part will be described with reference to FIG.

First, the valve body 33 has a power piston 41 fixed to the diaphragm 32, and a reaction disc 42 and a base end portion of the output shaft 43 are provided in a recess 41a formed in the power piston 41. It is fitted. The output shaft 43 serves as an input shaft of the master cylinder 8. A valve plunger 45 is attached to the tip of the input shaft 44 connected to the brake pedal 12 inside the valve body 33. A vacuum valve 46 is arranged behind the valve plunger 45.

The power piston 41 has a pressure introducing passage 50.
The pressure introducing passage 50 is always communicated with the space X formed around the valve plunger 45. This space X is always communicated with the second chamber 35. A valve seat 47, on which the vacuum valve 46 is seated, is formed at the end of the pressure introducing passage 50 that opens toward the space X. In addition, the vacuum valve 46 is a valve plunger 45.
The valve seat 45a formed at the rear end is also seated on and off.

In the above structure, it is assumed that a negative pressure is being 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. 2, but is separated from the valve seat 47. There is. Therefore, the pressure introducing passage 5
The negative pressure from 0 is introduced into the second chamber 35 through the space X, and the boosting action is not performed.

When the brake pedal 12 is depressed,
The input shaft 44 and hence the valve plunger 45 are moved forward (moved leftward 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 introducing passage 50 are
Communication with the vacuum valve 46 and then the valve seat 45
a is separated. By separating the vacuum valve 46 and the valve seat 45a, the atmospheric pressure from the rear of 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 to the valve plunger 45 and thus the brake pedal 12 via the reaction disc 42.
When the depression operation force of the brake pedal 12 is released, the return spring 36 (see FIG. 1) returns to the state of FIG. 2 to prepare for the next boosting action.

The part described above is the same as the known vacuum booster, but in this embodiment, the negative pressure of the first chamber 34 is introduced into the pressure introducing passage 50 for slip control. The state and the state where atmospheric pressure is introduced are switched. That is, the first chamber 34 and the pressure introducing 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). This switching valve 38 has a pressure introducing passage 50 when demagnetized.
Is communicated with the first chamber 34, and atmospheric pressure is introduced into the pressure introduction passage 50 during excitation. When the switching valve 38 is excited and the atmospheric pressure is introduced into the pressure introducing passage 50, the space X and therefore the second chamber 35 becomes the atmospheric pressure even if the brake pedal 12 is not depressed, and as a result, A brake fluid pressure is generated in the master cylinder 8 by a boosting action.

Next, the control system will be described. The control system is
It is configured using a microcomputer, and is shown in FIG.
In the figure, 51 is a control means for performing engine control and brake control. The control means 51 includes each wheel 1F.
The signals from the sensors S1 to S4 that detect the rotation speeds of L to 1RR are input.

The control means 51 is a friction coefficient detecting means for detecting a friction coefficient of a road surface, a control target value setting means, a slip amount detecting means 52, an acceleration detecting means 53, a filter means 54, an engine control amount calculating means 55, a brake. The control amount calculation means 56, the slip determination means, and the output means for controlling the engine output and the brake are provided. From the control means 51, the engine output adjusting means 9 for the engine control and the liquid for the brake control are provided. Control signals are output to the pressure adjusting valves 15L and 15R, the open / close valves 16L and 16R, and the switching valve 38. Engine output adjusting means 9
The engine output is adjusted by driving a sub-throttle valve (not shown) provided in the intake passage in addition to the main throttle valve that is interlocked with the accelerator pedal 10.

A detailed description will be given below. [Detection of road friction coefficient] The friction coefficient detecting means detects the friction coefficient of the left and right portions of the road on which the left and right drive wheels 1FL and 1FR roll, and the detection is performed by the corresponding left and right driven wheels 1RL. , 1RR wheel speed Vr and its acceleration VG
And based on.

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

-(1) Formula-VG = Gk1 × {Vr (k) -Vr (k-100)}-(2) Formula-VG = Gk2 × {Vr (k) -Vr (k-500)} Gk1 and Gk2 are coefficients. Also, Vr (k) is present, Vr (k-100) is 100 msec ago, and Vr (k-500) is 50
Each wheel speed is 0 msec before.

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.

[0036]

[Table 1] [Setting of control target value] This control target value is the front wheel 1FL,
It is a target value as the slip amount of 1FR, and is calculated based on the wheel speed Vr and the friction coefficient μ. That is, the engine control target value SET is equal to the wheel speed Vr of the faster driven wheel of the left and right driven wheels 1RL and 1RR.
And a coefficient of friction μ, the value is reduced as the wheel speed Vr increases, and the value is reduced as the coefficient of friction μ decreases. A map set to a value higher than the engine control target value is used to calculate the brake control target value SBT.

[Slip amount detection] Slip amount detection means 5
Reference numeral 2 denotes the wheel speed VFL, VFR of the left and right driving wheels 1FL, 1FR, whichever is faster from the wheel speeds VFL, VFR of the left and right driven wheels 1RL, 1RR.
Subtracting r, the slip amounts SL and SR of both wheels are obtained.

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

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

[Acceleration Detection] The acceleration detecting means 53 detects the acceleration of the driving wheels by obtaining the time change rate DEN of each of the calculation variables EN of the engine control amount and the brake control amount. For the detection, the acceleration may be directly calculated from the wheel speed of the driving wheel, or an acceleration sensor may be used, but in the case of this example, the acceleration of the driving wheel is indirectly obtained by obtaining DEN from the above EN. It is what you are looking for. The DEN includes differential terms of wheel speeds VFL and VFR of 1FL and 1FR.

[Filter Means] The filter means 54 obtains the smoothed acceleration by reflecting the previous value in a predetermined ratio to the acceleration detected by the acceleration detecting means 53. In the case of this example, the DEN is used. Processed and annealed DE
Get N. Specifically, the smoothed DEN (smoothed acceleration) is obtained by exponential smoothing of the following equation that reflects the previous output value DEN (k-1) by the predetermined ratio TE on the current detected value DEN (k).

Normalized DEN = DEN (k) × (1-TE)
+ DEN (k-1) × TE [Engine control amount calculation] Engine control amount calculation means 55
Is a calculation map EN for the engine control amount based on the average value of the slip amounts SL and SR of the driving wheels detected by the slip amount detecting means 52, and the time change rate DEN of the EN as parameters. Calculated from (Table 2).

[0044]

[Table 2] In this case, the symbol ZO shown in the above map represents holding of the opening of the sub-throttle valve, N represents closing movement, and P represents opening movement. The subscripts S, M, and B of N and P represent the magnitude of the control amount, and "S" is small (small opening amount, small closing amount), "M".
Is medium (during opening and closing), "B" is large (large opening,
It means a large amount of closing motion.

[Calculation of Brake Control Amount] The brake control amount calculation means 56 detects the slip amounts SL and SR detected by the slip amount detection means 52 for each drive wheel.
A map that is basically set with the same tendency as that shown in Table 2 above by using each calculation variable EN for the brake control amount based on the above and the time change rate DEN of the EN as parameters (the description is omitted). Ask more.

However, regarding the time change rate DEN,
The DEN obtained by the acceleration detecting means 53 and the smoothed DEN obtained by the filter means 54 are used separately.

That is, the brake control amount calculation means 56
Is the calculation of the control amount of the DEN (k) when the amount of change DEN of the DEN {absolute value of the value of DEN (k) -DEN (k-1)} obtained by the acceleration detecting means 53 is less than a predetermined value Ko. When the change amount .DELTA.DEN is equal to or larger than the predetermined value Ko, the smoothed DEN is used.

Further, the brake control amount calculation means 56
Includes 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 TE is set to increase as the ΔDEN increases.

FIG. 3 shows the flow of the above brake control amount calculation. First, various data are input, and the brake control amount is calculated while the brake control is being performed (steps P1 and P2). That is, the change amount Δ
If DEN is less than Ko, the brake control amount is calculated using the current detected value DEN (k) (steps P3 to P).
5). On the other hand, if the amount of change ΔDEN is Ko or more,
The reflection rate TE of the previous value in the filter means 54 is obtained based on the change amount ΔDEN, the smoothed DEN is obtained using this TE, and the brake control amount is calculated using the smoothed DEN (step P3). → P6 → P7 →
P5).

[Slip Judgment] The larger value of the slip amounts SL and SR of the drive wheels is the engine control target value S.
When it becomes ET or more, it is determined that engine control is required, and when SL or SR becomes the brake control target value SBT or more, it is determined that it is for brake control.

[Output control] The engine control is executed by driving the sub-throttle valve with the control amount obtained by the engine control amount calculation means 55, and the brake control is performed by the brake control amount calculation means 56. This is performed by outputting a control signal according to the control amount obtained for each drive wheel to the hydraulic pressure adjusting valves 15L, 15R (duty control).

[Slip Control Example] FIG. 4 shows an example of slip control. That is, up to time t ₁ ,
Since no large slip has occurred on the drive wheels, engine control is not performed, so the sub-throttle valve is fully open and the throttle opening Tn (combined opening of both main and sub throttle valves, The opening degree of the throttle valve having the smaller opening degree is the opening degree TH · M of the main throttle valve corresponding to the accelerator pedal depression amount.

[0053] In time point t _1, the slip amount of the drive wheel, a large slip incurred became engine control target value SET. In this time point t _1, the throttle opening is reduced at a stroke to a preset lower limit control value SM (feed-forward control). Then, once the SM is set, the opening degree of the sub-throttle valve is controlled so that the slip amount of the drive wheels becomes the engine control target value SET. At this time,
The throttle opening Tn becomes the sub-throttle valve opening TH · S.

[0054] In t ₂ time is when the slip amount of the drive wheels becomes the brake control target value SBT above, both this time, the brake fluid pressure is supplied to the drive wheels, an engine control and brake control The slip control is started by. The brake fluid pressure is controlled so that the slip amount of the drive wheels becomes the brake control target value SBT.

[0055] In t ₃ time, the slip amount of the drive wheels is at when it becomes less than the brake control target value SBT, thereby, the brake fluid pressure is gradually reduced, eventually the brake fluid pressure becomes zero. However, engine control is still continued. In the embodiment, the condition for ending the engine control is the time when the slip amount converges on SET.

[Effects of Resonance of Vehicle Suspension] In FIG. 5, the curve shown by the solid line shows the wheel speed and acceleration of the drive wheels when there is no effect of resonance of the vehicle suspension, and the curve shown by the broken line is , A model in which a cyclic load is applied to the drive wheels due to the resonance of the suspension and the acceleration of the drive wheels fluctuates.

That is, as indicated by the solid line, when the wheel speed of the drive wheels is accelerated and the slip amount increases due to the depression of the accelerator pedal 10, the engine control and the brake control described above are executed to suppress the increase of the slip amount. The
The wheel speed rises slowly, reaches a peak, and then decreases. On the other hand, the acceleration of the driving wheels peaks in the process of increasing the wheel speed, and then largely changes from a positive value to a negative value when the wheel speed reaches its peak. Then, the actual acceleration becomes as indicated by the broken line by adding the variation due to the resonance of the suspension to the above solid line.

As is clear from the figure, the amount of change ΔG in acceleration is small until the wheel speed steadily rises even when the suspension resonance influences, but the above change occurs when the wheel speed reaches its peak. 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 the present embodiment, when the above-mentioned ΔDEN is less than the predetermined value Ko, the DEN obtained by the acceleration detecting means 53 is used to calculate the brake control amount, so that the wheel speed peaks in FIG. Up to this point, the brake control amount is calculated according to the actual acceleration. At this time, since the amount of change in acceleration is small, there is no large change in the braking force, and instead, the slip of the drive wheels can be quickly converged by the brake control that is accelerated by the change in 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 DEN is used in the calculation of the brake control amount. Therefore, even if the change in acceleration is large, excessive fluctuations in the braking force will not occur. To be prevented. Therefore, it is possible to prevent the vibration acceleration of the suspension, and since the slip of the drive wheels is beginning to show a convergence tendency at this time, the brake control may be delayed with respect to the actual fluctuation of the acceleration. Even if there is, there is little trouble. Further, as described above, the brake control is smoothed D
Even if it is performed based on EN, engine control is performed with good responsiveness based on DEN corresponding to the actual acceleration, so there is little trouble in terms of slip convergence.

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

[Brief description of drawings]

 The drawings show embodiments of the 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 flow chart of a brake control amount calculation.

FIG. 4 is a diagram showing an example of changes over time in a slip amount of driving wheels in slip control.

FIG. 5 is a diagram showing an influence of suspension resonance on acceleration of driving wheels.

[Explanation of symbols]

 1FL, 1FR Drive Wheel 2 Engine 7FL to 7FR Brake 9 Engine Output Adjusting Means 51 Control Means 52 Slip Amount Detecting Means 53 Acceleration Detecting Means 54 Filter Means 55 Engine Control Amount Calculating Means 56 Brake Control Amount Calculating Means

Claims (3)

[Claims] 1. An engine control means for reducing engine output so that a slip amount of a drive wheel with respect to a road surface when a vehicle is accelerated reaches a target value, and a slip amount of the drive wheel with respect to a road surface reaches a target value. Brake control means for controlling a braking force applied to the drive wheel, wherein the engine control means and the brake control means calculate respective control amounts based on the slip amount of the drive wheel and the acceleration of the drive wheel. A slip control device for a vehicle, comprising: a control amount calculating means for controlling a slip amount of the driving wheel, an acceleration detecting means for detecting an acceleration of the driving wheel,
Filter means for obtaining a smoothed acceleration by reflecting a previous value in a predetermined ratio to the acceleration detected by the acceleration detecting means, and the control amount calculating means of the engine control means is detected by the slip amount detecting means. The control amount calculation means of the brake control means calculates the control amount based on the slip amount of the drive wheel and the acceleration detected by the acceleration detection means, and the control amount calculation means of the brake control means calculates the control amount of the drive wheel detected by the slip amount detection means. A slip control device for a vehicle, which calculates a control amount based on a slip amount, an acceleration detected by the acceleration detection unit, and an acceleration selected from the smoothed acceleration obtained by the filter unit. .. 2. The control amount calculation means of the brake control means uses the detected acceleration for calculation of the control amount when the change amount of the acceleration detected by the acceleration detection means is less than a predetermined value, and the change amount is predetermined. The vehicle slip control device according to claim 1, wherein the smoothed acceleration is used when the value is equal to or more than a value. 3. The vehicle according to claim 1, wherein the control amount calculation means of the brake control means increases the reflection rate of the previous value in the filter means as the amount of change in acceleration detected by the acceleration detection means increases. Slip control device.