JP3207455B2 - 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 for preventing a drive wheel from slipping too much on a road surface.

[0002]

2. Description of the Related Art Various slip control devices (traction control devices) have been proposed which prevent the driving wheels from slipping on the road surface during acceleration of the vehicle or the like, thereby satisfying acceleration performance and vehicle stability. ing.

[0003] The slip control is performed by reducing the torque applied to the driving wheels. Therefore, the braking control for applying a braking force to the driving wheels and the engine for reducing the generated torque (output) of the engine are performed. Control is performed. In both of the brake control and the engine control, feedback control is generally performed so that the actual slip value of the drive wheels with respect to the road surface becomes a predetermined target value.

Japanese Patent Laid-Open No. 63-137 discloses that slip control is performed by both brake control and engine control.
In this publication, only engine control is performed when the slip value of the drive wheel is small, and both engine control and brake control are performed when the slip value of the drive wheel is large. Are disclosed. Further, the above-mentioned publication discloses that when the vehicle is in a stuck state, the engine control is stopped and the slip control is performed only by the brake control.

[0005]

By the way, when the vehicle escapes from the stuck state, particularly immediately after the vehicle escapes, the slip control of the driving wheels is suppressed because the slip of the driving wheels is suppressed, and as a result, the driving wheels are stopped. There is a possibility that the applied torque to the vehicle suddenly increases, causing sudden acceleration contrary to the driver's will. Also, due to the suspension of slip control,
There is also a risk that stacking may occur again.

Accordingly, it is an object of the present invention to provide a vehicle slip control device capable of satisfying both the prevention of sudden acceleration after exiting the stack and the prevention of re-stacking.

[0007]

In order to achieve the above object, the present invention has the following configuration. That is, a brake adjusting means for adjusting the braking force to the drive wheels, and a brake for controlling the brake adjust means so that the slip value of the drive wheels with respect to the road surface becomes a predetermined brake target value. Key control means, stack detection means for detecting that the vehicle is in a stuck state, escape detection means for detecting when the vehicle has escaped from the stack, and a vehicle stack detected by the stack detection means. The first target value changing means for gradually decreasing the brake target value, and the brake target value when the escape detection means detects that the vehicle has escaped from the stuck state. A second target value changing means for gradually increasing the value; and a vehicle speed equal to or higher than a predetermined vehicle speed when the brake target value is being changed by the second target value changing means. Brake control stopping means for stopping the control by the brake control means, an engine control means for controlling an engine generated torque so that a slip value of a drive wheel with respect to a road surface becomes an engine target value, and When the vehicle stack is detected by the means,
And an engine control prohibiting unit for prohibiting control of the generated torque of the engine by the engine control unit. Preferred embodiments on the premise of the above solution are as described in claim 2 and the following claims.

[0008]

According to the first aspect of the present invention, when escape from the stack is detected, the brake target value that has been changed to a small value in the stack is gradually changed to a large value. Thus, rapid acceleration can be prevented and re-stacking can be prevented. In particular, during the stack, the slip control by the engine control is stopped, and the brake target value is gradually reduced by the first brake target value changing means. Increasing the value gradually is preferable for reliably preventing re-stacking. Further, it is possible to easily and reliably detect that there is no risk of re-stacking or sudden acceleration that makes the brake control unnecessary, when the vehicle speed becomes equal to or higher than the predetermined vehicle speed.

In addition to the above, since the slip control by the engine control is prohibited during the stack, it is possible to obtain the generated torque of the engine according to the delicate accelerator operation performed by the driver for the escape from the stack. This is preferable on escape from the stack. In addition, since the brake target value is gradually reduced during the stacking, it is possible to prevent or reduce a situation in which the slip control by the brake control gives a feeling of strangeness to a delicate accelerator operation by the driver. It is preferable that the slip control at the time of exiting the stack is also continuously performed only by the brake control.

According to the second or third aspect of the present invention, it is preferable to easily detect the escape from the stack.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. 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 of the vehicle body.
Torque generated by the clutch 3, the transmission 4, the differential gear 5,
Is transmitted to the left front wheel 1FL via the left drive shaft 6L and to the right front wheel 1FR via the right drive shaft 6R. 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.

[0012] Brakes 7FR to 7R mounted on each wheel
R is a hydraulic disk brake.
Further, a master cylinder 8 as a brake hydraulic pressure generating source is provided.
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 left front wheel brake 7FL (a wheel cylinder mounted in 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. It is connected.

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 branch pipes 13R and 14R for the rear wheels. The hydraulic pressure adjusting valves 15L and 15R are provided with a 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
The mode of release 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 via a pipe 25L to which a check valve 24L is connected by a pump 23L. Similarly, the brake fluid in the reservoir tank 22R is
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. The booster 11 is basically the same as a known vacuum booster. However, in the case of slip control, as will be described later, the booster action is performed even if the brake pedal is not depressed. Is performed.

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 formed by a diaphragm 32 and a valve body 33 fixed thereto. A chamber 34 and a second chamber 35 are defined. A negative pressure (for example, the negative pressure of the intake air of the engine 2) is always supplied to the first chamber 34. When the brake pedal is not depressed, the second chamber 35 is communicated with the first chamber 34, -The operation of the star 11 is stopped. 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 to perform a boosting function.

The 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 provided. Are fitted. 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 now 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. ing. 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 brake pedal 12 is released, the return spring 36 (see FIG. 1) returns to the state shown in FIG. 2 to prepare for the next boosting action.

Although the above-described parts are the same as those of the known vacuum booster, in this 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 38 (see FIG. 1) is connected to the pipe 37. The switching valve 38 allows the pressure introduction passage 50 to communicate with the first chamber 34 during demagnetization, and introduces atmospheric pressure into the pressure introduction passage 50 during excitation. When the switching valve 38 is excited and atmospheric pressure is introduced into the pressure introducing passage 50, the space X and hence the second chamber 35
Thus, even if the brake pedal 12 is not depressed, the atmospheric pressure is attained. As a result, a boosting action is performed to generate a brake hydraulic pressure in the master cylinder 8.

FIG. 3 schematically shows a control system. In FIG. 3, U is a control unit constituted by using a microcomputer.
Signals from sensors or switches S1 to S7 are input. The sensors S1 to S4 detect rotation speeds of the wheels 1FL to 1RR. The switch S5 is an accelerator switch that is turned on when the accelerator pedal 10 is fully closed. Switches S6 and S7 are each
The switch is activated when the key pedal 12 is depressed, for example, one switch is normally open and the other is normally closed. In addition, although output from the control unit U to each device shown in FIG. 3, reference numeral 9 denotes torque adjusting means for adjusting the generated torque of the engine 2. The torque adjusting means 9 adjusts the intake air amount, for example,
Alternatively, the generated torque is adjusted by a combination of the number of fuel cut cylinders and the ignition timing adjustment.

Next, an outline of the slip control will be described with reference to FIG.
Will be described with reference to FIG. In FIG. 4, the left driving wheel 1F
An example is shown in which a slip does not occur in L and a large slip occurs in the right drive wheel 1FR, and it is assumed that the control is not related to the stack. It should be noted that a special control described later is performed while the vehicle is in the stack and immediately after the vehicle exits the stack, so that the general slip control during traveling will be described first, and the control related to the stack will be described later. It shall be.

First, slip control during normal running will be described with respect to engine control. The engine control is started when a larger one of the slip values of the left and right front wheels 1FL and 1FR is equal to or greater than a predetermined start threshold (time t1 in FIG. 4).

The engine control is performed by performing feedback control of the torque adjusting means 9 so that the actual slip value becomes the target value STE for the engine. The engine control is stopped when the accelerator is fully closed or when the time during which the actual slip value has become the control continuation threshold SC (smaller than the engine target value) has continued for a predetermined time or more (FIG. 4 from t6 to t7).

Next, the brake control will be described. The brake control is started when all of the following conditions are satisfied. The first start condition is that the engine is being controlled. The second start condition is that the difference between the actual slip values of the left and right driving wheels 1FL and 1FR is equal to or greater than a predetermined value (t2 in FIG. 4). The third start condition is that the vehicle speed is a predetermined first speed.
Vehicle speed V1 or less. The fourth start condition is that a predetermined delay time described later has elapsed.

In anticipation of a response delay prior to the start of the brake control, the switching valve 38 is excited at the start of the engine control, the booster 11 is brought into a boosting operation state, and the hydraulic pressure adjusting valve 15L is started. , 15R are in the relief position, and the on-off valves 16L, 16R are closed. Then, after the switching valve 38 is excited, when the actual slip value shows a predetermined deceleration (the time until the predetermined deceleration is shown is the delay time, and in FIG. 4, between t2 and t3). , The brake control is started.

The brake control is performed on the left and right driving wheels 1FL, 1F.
R is independently controlled by feedback control of the fluid pressure regulating valves 15L and 15R such that the actual slip value becomes the brake target value STB (> STE) (duty). control).

The suspension of the brake control is performed when any one of the following conditions is satisfied. The first stop condition is when engine control is stopped. The second stop condition is when the vehicle speed becomes higher than a predetermined second vehicle speed V2 (V2> V1). The third stop condition is that the control signals for the left and right hydraulic pressure control valves 15L, 15R both indicate a pressure reduction and for a predetermined time (500 msec in the embodiment).
c) This is the time when the continuation is continued (t4 to t5 in FIG. 4).

The fourth stop condition is a left and right brake 7F.
This is when the brake fluid pressures of L and 7FR are both zero. The fifth stop condition is when one of the switches S6 and S7 detects that the brake pedal 12 is depressed (the brake pedal 12 is depressed by the switches S6 and S7). Is detected, the start of the brake control is prohibited).

When the brake control is stopped, the switching valve 38 is operated as long as the engine control is performed, the hydraulic pressure adjusting valves 15L and 15R are in the relief positions, and the on-off valve 1
6L and 16R are closed (the same state as the standby state until the start of the brake control). When the engine control is stopped or the brake pedal 12 is depressed, the switching valve 38 is demagnetized.

Stack-Related Slip Control Stack-related control is performed as follows. First, engine control is prohibited and only brake control is performed. Second, during stacking, the brake target value is gradually reduced. Third, when the vehicle escapes from the stack, the brake target value is gradually increased.

The stuck state means that the vehicle speed is lower than a predetermined vehicle speed (10 km / h or less in the embodiment) and that the difference between the left and right driving wheel speeds is a predetermined value or more (a difference of 50% or more). It is considered that the two conditions of a certain time are satisfied. When the vehicle escapes from the stack, the vehicle speed is increased and the difference between the left and right driving wheel speeds is reduced (in the embodiment, less than 20%). . Brake when exiting the stack
The key control is stopped when the vehicle speed is equal to or higher than a predetermined vehicle speed, for example, 20 km.
/ H or more.

Next, a control example of the present invention will be described with reference to flowcharts shown in FIG. 5 and subsequent figures. In the following description, P indicates a step. FIG. 5 shows the overall flow. First, at P0, a signal from each sensor or the like is input, and at P1, the rotational speeds WSRL and WSRR of the left and right drive wheels 1FL, 1FR are averaged to obtain The vehicle speed VS is calculated.

At P2, a first target value STE for engine control and a second target value STB for brake control are determined in a known manner (STB> STE). In P3,
The slip value SFL of the left driving wheel 1FL is equal to its rotational speed W.
The vehicle speed VS is calculated by subtracting the vehicle speed VS from the SFL. Similarly, the slip value SFR of the right drive wheel 1FR is calculated by subtracting the vehicle speed VS from the rotation speed WSFR.

In the processing of P4 to P6, the larger of the left and right drive wheel slip values SFL and SFR is set as the engine control slip value SA. At P7, a stack control described later is performed. In P8, it is determined whether the slip flag is 1 or not. When the slip flag is 1, it means that the slip control is being performed (at least the engine is being controlled). If the determination in P8 is NO, a start determination of engine control described later is made in P9, and then an end determination described later is made in P10.

If the determination in P8 is YES, the engine is controlled in P11, and then in P12,
It is determined whether the brake flag is "1". When the brake flag is "1", it means that the brake control is being performed. If the determination in P12 is NO, a brake start determination, which will be described later, is made in P13.
Move to. If the determination in P12 is YES, P
After the brake control is performed at 14, the program proceeds to P10.

FIG. 6 shows the contents of P9 in FIG. First,
At P21, the actual slip value SA for the engine
Is greater than or equal to a predetermined value indicating a predetermined start threshold value. If the determination in P21 is NO, it means that the slip control is unnecessary, and the program returns to P1 as it is. If the determination in P21 is YES, the slip flag is set to 1 in P22, engine control is started in P23, and preparation for starting brake control is made in P24. Specifically, the preparation in P24 is performed by exciting the switching valve 38 and causing the master cylinder 8 to brake.
The hydraulic pressure is generated, and the hydraulic pressure adjusting valve 15L,
5R to the relief position, and the on-off valves 16L, 16
R is closed.

FIG. 7 shows the contents of P13 of FIG. First, at P31, it is determined whether the vehicle speed VS is equal to or lower than the first vehicle speed V1. If the determination in P31 is YES, the rotational speed difference DNL between the left and right drive wheels 1FL and 1FR is calculated in P32, and then in P33,
It is determined whether or not the difference DNL is equal to or greater than a predetermined value.
If the determination in P33 is YES, in P34,
It is determined whether or not a predetermined delay time has elapsed since the occurrence of the difference (t2 to t3 in FIG. 4). If the determination in P34 is YES, after the brake flag is set to 1 in P35, in P36, the hydraulic pressure adjusting valve 15L,
Brake control by controlling 15R is started. NO in any of the names P31, P33, and P34
In the case of, the process ends.

FIG. 8 shows the contents of P10 in FIG. First, in P41, it is determined whether or not the accelerator is fully closed. If the determination in P41 is YES, P42
After the slip control, that is, both the engine control and the brake control are stopped, the respective flags are reset to 0 in P43.

If the determination in P41 is NO, in P45, it is determined whether or not the actual engine control slip value SA is equal to or smaller than the end threshold value SC. This P45
If the determination is YES, in P46, it is determined whether the state where SA is equal to or smaller than the end threshold value SC has continued for 1000 msec. YES in this determination of P46
In the case of, the program shifts to P42 and the slip control is stopped.

If the determination in P45 or P46 is NO, it is determined in P47 whether or not the vehicle speed VS is equal to or higher than the second vehicle speed V2. If the determination in P47 is YES, the process returns to P48. After stopping the brake control while gradually reducing the brake fluid pressure to prevent the occurrence of slip, the brake flag is reset to 0 in P49. The gradual suspension of the brake control is performed by reducing the pressure reduction signal to the hydraulic pressure regulating valves 15L and 15R at predetermined time intervals, but the degree of pressure reduction at one time increases. Restrictions are imposed.

If the determination in P47 is NO, it is determined in P50 whether the brake fluid pressures of the left and right driving wheel brakes 7FL and 7FR have both become zero. This P50
If the determination is YES, the brake control is stopped in P51, and then the flow shifts to P49. The estimation of the brake fluid pressure can be indirectly known by various methods already proposed, but a sensor for directly detecting the brake fluid pressure can also be used.

When the determination in P50 is NO, in P52, it is determined whether or not the control signals to the hydraulic pressure regulating valves 15L and 15R both indicate a pressure reduction.
If the determination is YES, it is determined whether or not the state where both the pressure reduction signals are 0 has continued for 500 msec. If the determination in P53 is YES, the brake control is stopped in P51. If the determination in P52 or P53 is NO, the process is terminated as it is (continuation of engine control and brake control).

FIG. 9 shows the contents of P7 in FIG. First, P
At 61, it is determined whether or not the vehicle speed VS is 10 km / h or less. If the determination in P61 is YES,
By the processing of P62 to P63, the difference between the left and right driving wheel speeds is 5
It is determined whether it is greater than 0%, and this determination is YES.
In this case, the stack is in progress. At this time, the flow shifts to P65.

In P65, the aforementioned brake control is prepared prior to the brake control (corresponding to P24 in FIG. 6). Then, in P66, the corrected target value STB is calculated by multiplying the current brake target value STB by a predetermined coefficient α (<1). Then, in P67, the brake control is performed based on the corrected target value.

After P67, it is determined by the processing of P68 to P71 whether or not it is time to escape from the stack. That is, when the vehicle speed VS shows a tendency to increase and the difference between the left and right driving wheel speeds does not become less than 20% (P68,
If the determination is NO in any of P70 and P71), it is determined that the stack is still in progress, and the process returns to P66.
, The brake target value STB is gradually reduced.

When it is time to escape from the stack,
The determination of P70 or P71 is YES, and in this case, the correction target value STB is calculated by multiplying the current brake target value STB by a coefficient β (> 1) in P72. Thereafter, in P73, the brake control is performed based on the corrected target value SRB.

At P74, it is determined whether or not the vehicle speed VS is equal to or higher than 20 km / h. If the determination in P74 is NO, the process returns to P72, and every time the process goes through P72, the flashing is performed.
The target value for key STB is gradually increased. If the determination in P74 is YES, the control related to the stack is no longer necessary, and the brake is released in P75. At the time of releasing the brake, control may be performed to gradually reduce the brake fluid pressure in each control cycle.

If the determination in P61, P63, P64 is NO, the control is not necessary in relation to the stack and the process is terminated.

Here, the brake switch S6 or S
7, if it is detected that the brake pedal 12 is depressed, the brake control is forcibly stopped by the interrupt processing for the flow chart.

Although the embodiment has been described, the slip value is calculated not as the difference between the driving wheel and the driven wheel, but as a ratio, for example, as the driving wheel speed / driven wheel speed, or (driving wheel speed-driven wheel speed). ) / Driven wheel speed.
The brake fluid pressure for the brake control is the same as that of the booster 11.
Alternatively, it may be generated by a dedicated pump without using.

The adjustment of the brake fluid pressure is performed by the second
The pressure may be adjusted by controlling the pressure in the chamber 35 (duty control of the switching valve 38). The suspension of the brake control related to the stack may be performed on the precondition that the brake target value has returned to the value set in P2 (the logical OR is logically OR with other suspension conditions). AND).

[Brief description of the drawings]

FIG. 1 is an overall system diagram showing an example of a vehicle to which the present invention is applied.

FIG. 2 is a sectional view showing a main part of the brake booster.

FIG. 3 is a diagram showing an input and output relationship with respect to a control unit.

FIG. 4 is a time chart schematically showing a control example of the present invention.

FIG. 5 is a flowchart showing a control example of the present invention.

FIG. 6 is a flowchart showing a control example of the present invention.

FIG. 7 is a flowchart showing a control example of the present invention.

FIG. 8 is a flowchart showing a control example of the present invention.

FIG. 9 is a flowchart showing a control example of the present invention.

[Explanation of symbols]

 Reference Signs List 1FL, 1FR Front wheel (drive wheel) 1RL, 1RR Rear wheel (driven wheel) 2 Engine 7FL-7RR Brake 8 Master cylinder 9 Torque adjusting means 11 Brake booster (power booster) 12 Brake pedal 15L, 15R Hydraulic pressure adjusting valve 16L, 16R On-off valve 38 Switching valve (switching between negative pressure supply and atmospheric pressure supply) U Control unit S1 to S4 Wheel speed sensor

Continuation of front page (56) References JP-A-63-31857 (JP, A) JP-A-3-143758 (JP, A) JP-A-63-137047 (JP, A) JP-A-2-286457 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60T 8/58 F02D 29/02 311 F02D 45/00 312 F02D 45/00 345

Claims (3)

(57) [Claims] A brake adjusting means for adjusting a braking force applied to a driving wheel; and a brake adjusting means for adjusting a slip value of the driving wheel to a road surface to a predetermined braking target value. Brake control means for controlling, and stack detection for detecting that the vehicle is in a stuck state
Means, escape detection means for detecting when the vehicle has escaped from the stack , and a vehicle stack detected by the stack detection means.
The brake target value is gradually reduced.
A first target value changing means gradually, the escape when the vehicle that has been detected is when the escaped from the stack state by the detecting means, gradually increases to go second target value changing means a target value for the brake The brake target value by the second target value changing means.
When the vehicle speed exceeds the specified vehicle speed while changing
A stopping means for stopping the control by the brake control means.
And the slip value of the drive wheels with respect to the road surface
Engine control to control the generated torque of the engine
Control means and the stack detection means detects a vehicle stack.
The engine is controlled by the engine control means.
And an engine control prohibiting unit for prohibiting torque control of the vehicle. 2. The method of claim 1, determines that the escape detection means, based on the difference of the left and right drive wheel speed is when the escaped from the stack state, this
And a slip control device for a vehicle . 3. The method of claim 1, wherein the escape detection means, based on the difference of the left and right drive wheel speed and the state of change of vehicle speed, determines that it is time escaped from the stack state, characterized in that Vehicle slip control
Equipment .