JPH05170081A - Traction control device for vehicle - Google Patents

Abstract

PURPOSE:To secure vehicle stability and prevent the generation of an excessive speed reducing feeling in the case of performing sudden accelerator return operation on the basis of the generation of an acceleration slip in a vehicular traction control device for suppressing the acceleration slip including brake control. CONSTITUTION:There is provided an acceleration slip control inhibiting means (d) for inhibiting acceleration slip brake control when the accelerator opening detection value is smaller than the specified value at the time of an acceleration slip being generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle traction control device for suppressing acceleration slip including brake control.

[0002]

2. Description of the Related Art Conventionally, as a vehicle traction control device for suppressing acceleration slip by using both internal combustion engine output control and brake control, for example, Japanese Patent Application Laid-Open No. 61-8524.
The device described in Japanese Patent No. 8 is known.

[0003]

However, in the above-described vehicle traction control device, when an acceleration slip of a predetermined value or more occurs regardless of the accelerator opening degree, the internal combustion engine output is obtained only by the acceleration slip condition. Since both control and brake control are performed, when the accelerator pedal is suddenly released due to the occurrence of acceleration slip, not only the engine brake will act, but also the brake pressure applied by the acceleration slip brake control. Depressurization is delayed, an excessive feeling of deceleration occurs, the driving wheels tend to lock, and vehicle stability deteriorates.

The present invention has been made in view of the above-mentioned problems, and in a traction control device for a vehicle for suppressing acceleration slip including brake control, a rapid accelerator return operation is performed based on the occurrence of acceleration slip. When performing the above, it is an object to prevent the occurrence of excessive deceleration feeling and to secure the vehicle stability.

[0005]

In order to solve the above problems, the vehicle traction control device of the present invention comprises means for prohibiting the acceleration slip brake control when the accelerator opening detection value is smaller than a predetermined value when an acceleration slip occurs. did.

That is, as shown in the claim correspondence diagram of FIG. 1, an acceleration slip brake control system a for applying a braking force to the drive wheels so as to suppress the acceleration slip depending on the occurrence of the acceleration slip, and an acceleration slip of the drive wheels. Acceleration slip detection means b for detecting the accelerator opening, accelerator opening detection means c for detecting the accelerator opening, and when the acceleration slip detection value is equal to or greater than the acceleration slip threshold, acceleration is performed if the accelerator opening detection value is smaller than a predetermined value. An acceleration slip control prohibiting means d for prohibiting slip brake control is provided.

[0007]

When the acceleration slip detection value by the acceleration slip detection means b is equal to or greater than the acceleration slip threshold value during acceleration traveling or starting when acceleration slip occurs, the accelerator opening degree detection value from the accelerator opening degree detection means c Is greater than or equal to a predetermined value, the acceleration slip brake control system a is activated, and braking force is applied to the drive wheels in order to suppress the acceleration slip depending on the state of occurrence of the acceleration slip.

However, even when the acceleration slip detection value by the acceleration slip detection means b is equal to or more than the acceleration slip threshold value, the acceleration slip is detected when the accelerator opening detection value from the accelerator opening detection means c is smaller than a predetermined value. In the control prohibiting means d, the acceleration slip brake control is prohibited.

Therefore, when the accelerator pedal is rapidly returned based on the occurrence of the acceleration slip, the acceleration slip brake control is prohibited while the accelerator small opening condition is satisfied, so that the accelerator pedal is rapidly returned. The engine brake only acts on the basis of this, and the generated acceleration slip is suppressed by the engine brake. At the same time, the drive wheels tend to lock even if excessive deceleration feeling occurs, such as when acceleration slip brake control is performed. It is also prevented that the stability is lowered.

[0010]

【Example】

 (First Embodiment) The configuration will be described.

FIG. 2 is an overall view of a braking / driving system control system for a rear-wheel drive vehicle to which the vehicle traction control device according to the first embodiment of the present invention is applied.

In this rear-wheel drive vehicle, the throttle control for controlling the motor throttle opening so that the rear-wheel slip ratio falls within the optimum allowable range when acceleration slip occurs, and the left and right rear wheels independently when acceleration slip occurs. A traction control system (equal to an acceleration slip brake control system on the brake control side) that is used together with a brake control that applies braking force is provided, and front and rear wheel brake fluid pressure control is performed to prevent wheel lock during deceleration slip. It is equipped with an anti-skid brake control system.
And the centralized electronic control of these systems is the traction control system & anti-skid brake control system electronic control unit TCS / ABS-ECU (hereinafter TCS / ABS-ECU
Abbreviated).

The TCS / ABS-ECU includes a right front wheel speed sensor 1
Right front wheel speed sensor value VWFR, left front wheel speed sensor 2 left front wheel speed sensor value VWFL, right rear wheel speed sensor 3 right rear wheel speed sensor value VWRR, and left rear wheel speed sensor 4 Left rear wheel speed sensor value VWRL, lateral acceleration sensor value YG from lateral acceleration sensor 5, switch signal SWTC from TCS switch 6, switch signal SWST from brake lamp switch 7, throttle control module TCM (hereinafter, Throttle 1 actual opening DKV from TCM)
And the automatic transmission control unit A /
Gear position signal and shift-up signal from TC / U (hereinafter abbreviated as A / TC / U) and engine rotation from the engine centralized electronic control unit ECCS C / U (hereinafter abbreviated as ECCS C / U) Number signal and the first throttle signal TVO1 from the first throttle sensor 16 (corresponding to accelerator opening detection means)
Then, the second throttle signal TVO2 or the like from the second throttle sensor 17 is input.

Then, from the TCS / ABS-ECU, the acceleration slip is detected, and the throttle 2 as a throttle opening / closing signal is detected.
The target opening DKR is output to TCM, and the solenoid signal as the brake pressure increase / decrease signal is output to each solenoid valve of the shared hydraulic unit TCS / ABS-HU (hereinafter abbreviated as TCS / ABS-HU). .. The throttle control side of this traction control is called TCS throttle control, and the brake control side is called TCS brake control.

The TCS / ABS-ECU detects deceleration slip and outputs a solenoid signal as a brake pressure increasing / decreasing signal to each solenoid valve of the TCS / ABS-HU. This anti-skid brake control is called ABS brake control.

In addition to the above output, the TCS / ABS-ECU outputs a lighting command to the TCS fail lamp 14 when the TCS fails, and outputs a lighting command to the TCS operation lamp 15 while the TCS is operating.

The TCM is a control circuit centering on a throttle motor drive circuit, which receives the first throttle signal TVO1 from the first throttle sensor 16 and outputs it to the TCS / ABS-ECU as the throttle 1 actual opening DKV. Or input the second throttle signal TVO2 from the second throttle sensor 17 as feedback information for the throttle 2 target opening DKR, or input the throttle 2 target opening DK from the TCS / ABS-ECU.
A motor drive current IM is applied to the throttle motor 18 based on R.

Here, the first throttle valve 19 provided with the first throttle sensor 16 is the accelerator pedal 2
The second throttle valve 21, which is a valve that operates in conjunction with 0, is provided in the engine intake passage 22 in series with the first throttle valve 19 and is opened and closed by the throttle motor 18. It is a valve that is used.

As a peripheral system, the traction control system has an air flow meter AFM as shown in the figure.
It has an ECCS C / U and an injector, and an engine centralized electronic control system that centrally controls fuel injection control, ignition timing control, idle speed correction, etc. is installed. When the ON signal is input, control for selecting a smaller valve opening of the first throttle signal TVO1 and the second throttle signal TVO2 (select low control) is performed to correct the transient characteristics, and the canister control and EGR control are performed. It will be canceled.

As a peripheral system, as shown in the figure, an A / TC / U and a shift solenoid are provided, and an automatic transmission control system for performing gear shift control, lockup control, etc. is installed. The gear position signal and shift-up signal are fetched from TCS / ABS-ECU.

Further, as a peripheral system, as shown in the figure, an ASCD actuator is provided, and a constant speed traveling control system for automatically controlling the vehicle speed so as to maintain the set vehicle speed is mounted, so as to prevent control interference, When the ON signal of the traction switch signal TCS SW is input, the opening control of the first throttle valve 19 is stopped, and when the OFF signal of the TCS SW is input, the return speed of the first throttle valve 19 is made gentle.

FIG. 3 is a hydraulic circuit diagram showing a brake fluid pressure control system commonly used for TCS brake control and ABS brake control for the left and right rear wheels independently.

This brake fluid pressure control system includes a brake pedal 27, a hydraulic booster 28, a master cylinder 30 having a reservoir 29, wheel cylinders 31, 32, and
33, 34 and shared hydraulic unit TCS / ABS-HU
, Pump unit PU, and first accumulator unit
AU1, 2nd accumulator unit AU2, front wheel side damping unit FDPU, rear wheel side damping unit RD
It is equipped with PU.

The TCS / ABS-HU has a first switching valve 35a.
, Second switching valve 35b, left front wheel pressure increasing valve 36a
And right front wheel pressure increasing valve 36b and left rear wheel pressure increasing valve 36
c, right rear wheel pressure increasing valve 36d, left front wheel pressure reducing valve 3
7a, a right front wheel pressure reducing valve 37b, a left rear wheel pressure reducing valve 37c, a right rear wheel pressure reducing valve 37c, a front wheel side reservoir 38a, a rear wheel side reservoir 38b, and a front wheel side pump 39.
a, the rear wheel side pump 39b, and the front wheel side damper chamber 40a
And a rear wheel side damper chamber 40b and a pump motor 41.

During normal braking and ABS brake control, both switching valves 35a and 35b are turned off as shown in order to introduce the hydraulic pressure from the master cylinder 30.
When the TCS brake is controlled, both switching valves 35a and 35b are turned to the ON position in order to introduce the hydraulic pressure from the second accumulator unit AU2. Then, for example, in the pressure increasing mode of the TCS brake control, both control valves 36c, 36d, 37c, 37d are as shown in the drawing.
In the OFF position and in the holding mode, the booster valve 36
Only c and 36d are set to the ON position, and in the depressurization mode, both control valves 36c, 36d, 37c and 37d are set to the ON position, the brake fluid from the wheel cylinders 33 and 34 is stored in the rear wheel side reservoir 38b, and further, By the rotation of the rear wheel side pump 39b, it is returned to the rear wheel side damper chamber 40b.

The first accumulator unit AU1 is used as a hydraulic pressure source for the hydraulic booster 28, and the second accumulator unit AU2 is used as a hydraulic pressure source for TCS brake control. Predetermined accumulator pressure is maintained by the common pump unit PU that draws in.

The front wheel side damping unit FDPU and the rear wheel side damping unit RDPU are shared hydraulic units TCS / AB in order to improve pedal feeling.
The influence of the change in hydraulic pressure on the S-HU is suppressed from affecting the master cylinder 30.

The operation will be described.

(B) Traction control action FIG. 4 is a control block diagram showing an outline of traction control performed by the TCS / ABS-ECU. The traction control logic can be roughly classified into the following four types of control.

(1) Calculation of Actual Slip State The signals of the wheel speed sensors 1, 2, 3 and 4 are filtered, and the actual slip state (slip amount, slip amount difference value) is calculated based on the wheel velocity value after the filtering process. ) Is calculated (corresponding to acceleration slip detection means).

(2) Calculation of Target Slip State The signal of the lateral acceleration sensor 5 is filtered to calculate the target slip state corresponding to the running state based on the turning / straight ahead determination based on the lateral acceleration and the vehicle speed.

(3) TCS brake control Comparing the actual slip state and the target slip state, the necessary brake pressure increase / decrease speed (control duty ratio) is calculated and output to TCS / ABS-HU.

(4) TCS throttle control Comparing the actual slip state and the target slip state, the necessary throttle opening and opening / closing speed are calculated and output to the TCM.

This control logic is characterized by low μ to high μ.
In order to secure the limit detectability (steering force, skill sound, etc.) based on the base chassis performance according to each road surface condition and to obtain active safety, the allowable slip state according to the magnitude of lateral acceleration, The allocation of throttle / brake control has been decided.

Further, in order to ensure stability during gear shifting and improve controllability at each gear position, throttle / brake control is performed according to the gear position.

Further, in order to suppress slip hunting and realize a smooth acceleration feeling and controllability, and to realize a responsive engine torque increase / decrease control, optimal throttle control is performed according to the engine speed.

(B) ABS brake control action When the deceleration slip of each wheel exceeds the deceleration slip threshold value during braking, the solenoid signal as a brake pressure increasing / decreasing signal is independently applied to each wheel of each solenoid valve of TCS / ABS-HU. It is done by outputting to.

By this control, the wheel lock is suppressed when the braking force becomes excessive and the wheel lock is likely to occur, such as at the time of low-friction coefficient road braking or sudden braking.
The braking stability of the vehicle and the braking distance can be shortened.

(C) Brake control operation request signal output process FIG. 5 is a flow chart showing the flow of the ABS brake control operation request signal output process operation performed by the TCS / ABS-ECU. Each step will be described below.

At step 50, the right front wheel speed sensor value VWF
R, left front wheel speed sensor value VWFL, right rear wheel speed sensor value VWRR
, The left rear wheel speed sensor value VWRL is read. In step 51, it is determined whether the deceleration slip amount calculated based on the read wheel speed signal is equal to or greater than the deceleration slip threshold value. When YES is determined in at least one of the front and rear wheels in step 51, the process proceeds to step 52, and AS = 1 is output as the ABS brake control operation request signal. When NO is determined in the step 51, the process proceeds to a step 53, and AS = 0 is output as the ABS brake control non-operation signal.

FIG. 6 is a flow chart showing the flow of the TCS brake control operation request signal output processing operation performed by the TCS / ABS-ECU. Each step will be described below.

In step 60, the right front wheel speed sensor value VWF
R, left front wheel speed sensor value VWFL, right rear wheel speed sensor value VWRR
, The left rear wheel speed sensor value VWRL is read. In step 61, it is judged whether the acceleration slip amount calculated based on the read wheel speed signal is equal to or more than the acceleration slip threshold value. At least one of the left and right rear wheels in step 61
If YES is determined in the wheel, the process proceeds to step 62,
TS = 1 is output as the TCS brake control operation request signal. When NO is determined in step 61, the process proceeds to step 63, in which TCS brake control non-operation signal T
S = 0 is output.

(D) ABS → TCS control switching action FIG. 7 (A) shows the TCS / ABS-ECU to ABS-T
Each step will be described below with the flowchart showing the flow of the control switching processing operation to the CS.

At step 70, it is judged if the ABS brake control is in operation.

In step 71, it is judged whether or not the TCS brake control operation request signal TS = 1 is output.

At step 72, the first throttle opening TV
It is determined whether O1 is equal to or greater than the vehicle speed-corresponding throttle opening calculation value θ (V).

The calculated throttle opening degree θ (V) for vehicle speed
Is given, for example, by the following formula. θ (V) = α · VFTF ² + β VFTF; front wheel speed average value In step 73, ABS brake control non-operation signal AS
It is determined whether or not = 0 is output.

When the above steps 70, 71 and 72 are satisfied, the routine proceeds to step 74, where a TCS throttle control start command is output.

When the above steps 70, 71, 72 and 73 are satisfied, the routine proceeds to step 75, where a TCS brake control start command is output.

The steps 71, 72 and 75 correspond to acceleration slip control prohibiting means.

Therefore, in the control switching from ABS to TCS, when the throttle opening condition of step 72 is satisfied, as shown in the time chart of FIG.
When the TCS brake control operation request signal TS = 1 is output at time t1 during the S brake control, the TCS throttle control is started immediately. However, the TCS brake control will be started after waiting the time t2 at which the ABS brake control non-operation signal AS = 0 is output. Thus, from time t1 to time t2, the ABS brake control and the TCS throttle control operate simultaneously, and the time t
At time 2, the ABS brake control is switched to the TCS brake control.

For example, when the TCS brake control operation request signal TS = 1 is output during the ABS brake control, and when the TCS brake control is immediately switched to, when the TCS brake control is performed in addition to the wheel cylinder residual pressure, the signal from the accumulator is output. When the TCS brake control is performed, a sufficient amount of increased pressure is applied to cause a feeling of deceleration, and when the TCS brake control is performed, there is residual liquid in the brakes during ABS brake control, so that sufficient pressure reduction control is performed. However, the brakes tend to drag and a feeling of deceleration occurs.

On the other hand, during the period from time t1 to time t2, the TCS throttle control is preceded while the ABS brake control is maintained, whereby the brake pressure in the ABS brake control can be reduced, and the brake control becomes excessive. Is suppressed.

Also, from time t1 to time t2, A
Pump 39a by continuing the BS brake control,
By operating 39b, the residual brake fluid in the reservoirs 38a, 38b can be almost eliminated.

When the TCS brake control operation request signal TS = 1 is output due to the occurrence of the acceleration slip, the first throttle opening TVO1 is equal to or larger than the vehicle speed corresponding throttle opening calculated value θ (V) in step 72. Imposing conditions T
The reason why the CS throttle control and the TCS brake control are switched to is that the first throttle opening TVO1, that is, when the TCS brake control is immediately switched to when the accelerator opening is small, a rapid return operation of the accelerator pedal 20 causes Not only the engine brake works but also the pressure reduction of the brake pressure applied by the TCS brake control is delayed and dragged, causing an excessive pressure reduction feeling.
While the rear wheels tend to lock and reduce stability, the TVO1
If <θ (V) is satisfied, TCS throttle control and TCS
Switching to brake control is prohibited and the accelerator pedal 20
It is possible to prevent excessive decompression feeling and deterioration of vehicle stability by only applying the engine brake by the rapid return operation of.

Further, the comparison reference value of the first throttle opening TVO1 is set to the vehicle speed-corresponding throttle opening calculation value θ (V) as shown in FIG. 10 because the air resistance component proportional to the square of the vehicle speed VFTF ( α ・ VFTF ² ) and rolling resistance β are used to obtain the running resistance at that time. The larger the running resistance, the larger the reference value of the first throttle opening TVO1 that is the reference value for TCS control. is doing. (E) TCS → ABS control switching action FIG. 7B shows a TCS / ABS-ECU to TCS to A
Each step will be described below with a flowchart showing the flow of the control switching processing operation to the BS.

At step 80, it is judged if the TCS brake control is in operation.

At step 81, it is judged if the ABS brake control operation request signal AS = 1 is output.

In step 82, it is judged whether or not the ABS brake control operation request signal ASFFR = 1 for the right front wheel and the ABS brake control operation request signal ASFFL = 1 for the left front wheel are simultaneously output.

At step 83, the first throttle opening TV
It is determined whether O1 is smaller than the vehicle speed corresponding throttle opening calculation value θ (V).

In step 84, it is judged whether or not the TCS brake control non-operation signal TS = 0 is output.

Steps 80, 81, 82 or steps 80, 81, 83 or steps 80, 81, 84
If either of the above is satisfied, the process proceeds to step 85 and AB
An S throttle control start command is output. When the process proceeds to step 85 after step 82 or step 83, the ABS throttle control start command is output and the TCS brake control stop command is output.

Therefore, the control switching from TCS to ABS is performed in step 82 as shown in the time chart of FIG.
When the ABS brake control operation request condition for the left and right front wheels of the vehicle is satisfied, the ABS brake control is immediately started when the ABS brake control operation request signal AS = 1 is output at time t3 during the TCS brake control. ..

As described above, the reason why the operation request of the front wheel which is the driven wheel is set as the switching condition is that the ABS operation request of the driven wheel is more accurate and earlier than that of the drive wheel. Further, the reason why the operation demands on the left and right front wheels are set as the switching condition is that, for example, when the low μ road braking in which the left and right front wheels are both slippery easily, the ABS actuation requests are easily issued to the left and right rear wheels.
It is preferable to give priority to S, and when only one of the left and right front wheels is requested to perform ABS operation, it often occurs due to road surface disturbance, wheel load change, bump overrun, split μ road, etc. , In this case, immediately TCS
This is because the vehicle stability is often impaired when the vehicle is stopped.

When the ABS operation request is issued during the TCS control, when the throttle opening condition in step 83 or the output condition of the TCS brake control non-operation signal TS = 0 in step 84 is satisfied, the ABS control is performed. ..

The effect will be described.

(1) When the TCS brake control operation request signal TS = 1 is output due to the occurrence of the acceleration slip, the condition that the first throttle opening TVO1 is equal to or more than the vehicle speed corresponding throttle opening calculated value θ (V) is satisfied. Since it is set to enter the TCS control, it is possible to prevent the occurrence of excessive pressure reduction feeling and the tendency of the rear wheels to lock, which would occur when the TCS control is immediately entered in the small throttle opening range, and to improve the vehicle stability. Can be secured.

(2) At the time of control switching from ABS to TCS,
Since the TCS throttle control is performed immediately, but the TCS brake control is performed after the ABS brake control is completed, it is possible to prevent the occurrence of a deceleration feeling due to excessive brake control and the deceleration feeling due to the brake dragging.

(3) At the time of control switching from TCS to ABS,
When the ABS brake control operation request is issued to the left and right front wheels, the ABS brake control is started immediately, so that the braking performance is improved at the time of low friction coefficient road braking or sudden braking without impairing the vehicle stability. Can be planned.

(4) The condition for switching from the ABS brake control to the TCS brake control is the termination of the ABS brake control, and the condition for switching from the TCS brake control to the ABS brake control is the ABS operation request for the left and right front wheels. Since the device is configured to perform different switching so as to give priority, it is possible to prevent control hunting between the ABS brake control and the TCS brake control while giving priority to ensuring braking performance.

(Second Embodiment) In the first embodiment, an example is shown in which the acceleration slip control prohibition of the present invention is applied in the switching control from the ABS brake control to the TCS throttle control and the TCS brake control. The second embodiment applies the acceleration slip control prohibition of the present invention in the acceleration slip state in which the TCS control is entered without presupposing the control. Since the device configuration is the same as that of the first embodiment device, its explanation is omitted.

FIG. 11 is a flow chart showing the flow of the TCS control processing operation performed by the TCS / ABS-ECU of the second embodiment apparatus, and each step will be described below.

At step 90, it is judged if the vehicle is in the acceleration slip state.

In step 91, the detected accelerator opening degree (first throttle opening degree TVO1) is given in the same way as the vehicle speed corresponding throttle opening calculated value θ (V).
It is compared whether it is included in the high accelerator opening range I or the low accelerator opening range II with (V) as a boundary.

If it is determined in step 91 that the accelerator opening is within the low accelerator opening area II, the routine proceeds to step 92, where TCS throttle control and TCS brake control are prohibited.

If it is determined in step 91 that the accelerator opening is within the high accelerator opening region I, the routine proceeds to step 93, where TCS throttle control and TCS brake control are executed.

The steps 90, 91 and 92 correspond to the acceleration slip control prohibiting means.

Therefore, also in the second embodiment, the effect described in (1) of the first embodiment can be obtained.

Although the embodiment has been described above with reference to the drawings, the specific structure is not limited to the first embodiment.

For example, in the embodiment, the application example to the traction control system by the throttle + brake is shown, but it can be applied to the system which performs the traction control only by the brake control.

In the embodiment, an example in which a preferable value according to the vehicle speed V such as a vehicle speed corresponding throttle opening calculation value θ (V) and a vehicle speed corresponding value f (V) is given as a comparison reference value of the accelerator opening is shown. However, a case where a predetermined fixed value is given is included, and the vehicle speed corresponding value is not a quadratic function of the vehicle speed,
It may be given as a one-hour function of the vehicle speed.

[0082]

As described above, according to the present invention, in a traction control device for a vehicle that suppresses an acceleration slip including brake control, when an acceleration slip occurs, When the accelerator opening detection value is smaller than a predetermined value, the acceleration slip brake control is prohibited.Therefore, when a sudden accelerator release operation is performed due to the occurrence of acceleration slip, excessive deceleration feeling is prevented and the vehicle stability is stabilized. It is possible to obtain the effect of ensuring the sex.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a vehicle traction control device of the present invention.

FIG. 2 is an overall view of a braking / driving system control system of a rear-wheel drive vehicle to which the vehicle traction control device of the first embodiment is applied.

FIG. 3 is a hydraulic circuit diagram showing a brake fluid pressure control system of a braking / driving system control system to which the vehicle traction control device of the first embodiment is applied.

FIG. 4 is a block diagram showing an outline of traction control in the first embodiment.

FIG. 5 is a flow chart showing a flow of ABS brake control operation request signal output processing operation performed by the TCS & ABS electronic control unit of the first embodiment device.

FIG. 6 is a flowchart showing the flow of TCS brake control operation request signal output processing operation performed by the TCS & ABS electronic control unit of the first embodiment device.

FIG. 7A is a TCS & AB of the first embodiment device.
ABS to TCS performed by S electronic control unit
In the flowchart showing the flow of control switching processing operation to
FIG. 7B is a flowchart showing the flow of the control switching processing operation from TCS to ABS.

FIG. 8 is a time chart when the control is switched from ABS to TCS.

FIG. 9 is a time chart when the control is switched from TCS to ABS.

FIG. 10 is a characteristic diagram of throttle opening degree corresponding to vehicle speed.

FIG. 11 is a flowchart showing a flow of TCS control processing operation performed by the TCS & ABS electronic control unit of the second embodiment device.

[Explanation of symbols]

 a acceleration slip brake control system b acceleration slip detection means c accelerator opening detection means d acceleration slip control prohibition means

Claims (1)

[Claims] 1. An acceleration slip brake control system for applying a braking force to a drive wheel in order to suppress the acceleration slip depending on the occurrence of the acceleration slip, an acceleration slip detection means for detecting an acceleration slip of the drive wheel, and an accelerator opening degree. When the acceleration slip detection value is equal to or greater than the acceleration slip threshold,
A vehicle traction control device comprising: an acceleration slip control prohibiting means for prohibiting acceleration slip brake control if the accelerator opening detection value is smaller than a predetermined value.