JP2813918B2 - Vehicle traction control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a traction control device for a vehicle, and more particularly, to a traction control device in a case where the speed of driven wheels in a normal running state is significantly reduced.

(Prior Art) In traction control of a vehicle, a target slip ratio is set based on a wheel speed of a driven wheel, and an output of an engine or an output of an engine is set so that a deviation between a driven wheel and a drive wheel, that is, an actual slip ratio converges on the target slip ratio. There is known a configuration in which a braking force of a vehicle is controlled to transmit engine power to wheels efficiently.

Japanese Patent Application Laid-Open No. 62-99231 discloses a traction control device that controls the slip ratio of a drive wheel so as to converge to a target slip ratio by the method described above. If speed is detected,
There is disclosed a slip control device that processes the detected value in accordance with the actual situation to prevent a malfunction of the control device.

(Problems to be solved) In the device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 62-99231,
If a deceleration that exceeds the maximum deceleration that can occur in the vehicle, that is, a change in the speed of the driven wheels that cannot physically occur under normal driving conditions, is detected, the detected value is appropriately processed. By doing so, it is possible to prevent the engine output from dropping due to the detection of the sudden deceleration and to prevent a sudden increase in the brake fluid pressure, etc., and to control the traction control operation appropriately.

However, such a method of processing the detected value so as to match the traction control has the following disadvantages. For example, in the case of traction control or anti-skid control, it is desirable to accurately detect a change in the speed of a driven wheel when performing rough road correction. However, if the detected value is used for control as described above, it may not be possible to perform accurate rough road correction.

(Means for Solving the Problems) Accordingly, the present invention provides a desired slip control without being affected by a running state in which a deceleration equal to or greater than the maximum deceleration that the vehicle can generate is detected. It is an object of the present invention to provide a traction control device that can maintain the vehicle traction and can appropriately perform a rough road correction and the like.

The object of the present invention is to provide a driving wheel speed detecting means for detecting the speed of each driving wheel, a driven wheel speed detecting means for detecting each speed of a driven wheel, the driving wheel speed detecting means and the driven wheel speed detecting. Means for calculating a slip rate of a driving wheel based on a detection value from the means, target slip rate setting means for setting a target slip rate based on a wheel speed of a driven wheel, and Control means for controlling the engine output or the braking force so as to converge to the rate, and the target slip is detected when a decrease in the wheel speed of the driven wheel exceeding the maximum deceleration that the vehicle can generate during normal driving is detected. Limiting means for limiting the rate of decrease in proportion thereto. That.

The above-mentioned maximum deceleration changes depending on the gear ratio of the currently selected traveling stage, and decreases as the gear ratio increases. That is, the higher the speed, the smaller the maximum deceleration.

Preferably, the value of the maximum deceleration for starting the operation of the limiting means for limiting the decrease in the target slip rate is
It is experimentally given according to the gear ratio, and is stored as a reference value. The reference value of the maximum deceleration corresponding to this gear ratio is compared with an actual detected value as to whether to limit the reduction of the target slip ratio.

In addition, the traction control device of the present invention may include a rough road correction unit that changes the content of the slip control when the traveling road is a rough road.

(Operation) According to the present invention, the slip ratio of each drive wheel is calculated from the speed detection result of each wheel. Further, a target slip ratio is set, and the control means controls the engine output or the braking force so that the slip ratio converges to the target value. In this case, when the deceleration of the driven wheel exceeding the maximum deceleration that can occur in the normal running of the vehicle is detected, the reduction of the target slip rate due to the influence of the detection of the deceleration is limited by the limiting means. .

That is, in this case, regardless of the detection of the deceleration, the slip control is performed as if the deceleration was not detected.

In this case, since the detected value of the deceleration is not corrected in the present invention, it is also possible to obtain the change in the acceleration of the driven wheel based on the detected deceleration and perform the rough road correction.

(Explanation of Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

Basic Configuration As shown in FIG. 1, the present invention comprises a driving wheel speed detecting means 100 for detecting the respective speeds of the left and right driving wheels, and a driven wheel speed detecting means 200 for detecting the respective speeds of the left and right driven wheels. A slip ratio calculation unit 300 that calculates a slip ratio of a drive wheel based on the detected values from the drive wheel speed detection unit and the driven wheel speed detection unit, and a target slip ratio setting unit 400 that sets a target slip ratio. The control means 500 for controlling the engine output or the braking force while changing the control method according to the driving state of the vehicle so that the slip ratio converges to the target slip ratio, and the detected deceleration of the driven wheels is the maximum of the vehicle. Limiting means is provided for limiting the target slip rate set by the target slip rate setting means 400 from decreasing in response to the detection of the deceleration when the deceleration is exceeded.

FIG. 2 is a system diagram of a hydraulic circuit for brake control of an engine and wheels of a vehicle to which the traction control according to the present invention is applied.

The vehicle A includes left and right front wheels, ie, driven wheels 1FL and 1FR, and rear wheels, ie, drive wheels 1RL and 1RR.

The engine 2 is mounted on the front of the vehicle body,
An automatic transmission 3 is connected to an output side of the engine 2, and a propeller shaft 4 is connected to an output side of the automatic transmission 3. The output of the engine 2 is transmitted to left and right drive wheels 1RL and 1RR via a differential gear device 5 connected to a propeller shaft 4 and left and right drive shafts 6L and 6R.

Configuration of Automatic Transmission The automatic transmission 3 includes a torque converter 11 and a multi-stage transmission gear mechanism 12 that provides a plurality of shift speeds. Further, the multi-speed transmission gear mechanism 12 includes a plurality of solenoids 13a for switching a hydraulic circuit to provide a desired speed. Further, the torque converter 11 includes a lock-up clutch, and includes a solenoid 13b for controlling this operation.

An automatic transmission control unit UAT is provided to control the solenoid 13a and the solenoid 13b.
The automatic transmission control unit UAT stores a shift control map and a lock-up control map, and the control unit UAT generates control signals to the solenoids 13a and 13b based on the maps. Controls gear shifting and lock-up.

For this purpose, the control unit UAT includes a signal from a main throttle valve opening sensor 61 for detecting the opening of the main throttle valve 43 and a sub-throttle valve opening sensor for detecting the opening of the sub-throttle valve 45. A signal from 62 and a signal from a vehicle speed sensor 63 for detecting the vehicle speed (a sensor for detecting the rotational speed of the propeller shaft 4 may be used instead).

Configuration of Brake Hydraulic Adjustment Mechanism A hydraulically operated brake system for braking each wheel 1FR to 1RR is provided. 1FR for each wheel for this purpose
Brakes 21FR to 21RR are provided corresponding to ~ 1RR. Each of the brakes 21FR to 21RR is provided with a caliper (brake cylinder) 22FR to 22RR.
, Brake hydraulic pressure is supplied through pipes 23FR to 23RR.

The brake system includes a brake pedal 25 to which a depressing force from an operator is input, a booster 26 for boosting the depressing force using a hydraulic booster, and a tandem-type master connected to the booster 26. A cylinder 27 is provided. The master cylinder 27 has a first discharge port 27a connected to the left front wheel brake 21FL via a brake pipe 23FL, and a second discharge port 27a.
Is connected to the left front wheel brake 21FL and the right front wheel brake FR via a brake pipe 23FR.

The booster 26 is connected to a pump 29 via a pipe 28 and receives supply of pressure oil from the pump.

A return pipe 30 is connected to the pump, through which excess pressure oil is returned to the reservoir tank. A branch pipe 28a branches from the pipe 28, and the branch pipe 28a
Is provided with an electromagnetic on-off valve 32. Booster device 26
A piping 33 extends from the valve, and the piping 33 is provided with an electromagnetic on-off valve 34 and a one-way valve 35 in parallel with the on-off valve 34.

The branch pipe 28a and the pipe 33 join at a position a on the downstream side, and the brake pipes 23RL and 23RR for the left and right rear wheels are joined to this portion.
Is connected.

These pipes 23RL and 23RR have solenoid on-off valves 36A and 3A, respectively.
7A is connected to the relief passages 38L and 38R connected downstream of the valves 36A and 37A, respectively.
36B and 37B are connected.

Similarly, solenoid on-off valves 36A 'and 37A' are connected to the front wheel brake pipes 23FL and 23FR, respectively.
Relief passage 38 connected downstream of A ', 37A'
For L 'and 38R', solenoid on-off valves 36B 'and 37B', respectively
Is connected.

Configuration of Engine Generated Torque Adjusting Mechanism An intake passage 41 communicates with the engine 2. The intake passage 41 has a main throttle valve 43 connected to an accelerator pedal 42 and a throttle opening adjusting actuator 44.
And a sub-throttle valve 45 connected to the sub-throttle valve. In this case, since the main throttle valve 43 and the sub-throttle valve 45 are arranged in series, the overall opening of the throttle valve matches the smaller of the two.

Configuration of control unit UTR for traction control These valves 32, 34, 36A, 37A, 36B, 37B, 36A ', 37
A control unit UTR for traction control is provided to control the operation of the actuators 44 of A ', 36B', 37B 'and the sub throttle valve 45. In other words, the control unit UTR controls the braking force of the wheels through the control of the output of the engine and the brake oil pressure for the purpose of traction control.

The control unit UTR receives signals from the wheel speed sensors 64 to 67 for detecting the respective wheel speeds, a main throttle opening sensor 61, a sub throttle opening sensor 62, a vehicle speed sensor 63, and an accelerator opening sensor 68. , Yaw rate sensor 69,
Signals from the shift sensor 70, the steering angle sensor 71, and the traction control mode selection switch 72 by manual operation are input.

The control unit UTR includes an input interface that receives signals from the above sensors, a microcomputer having a CPU, a ROM, and a RAM, an output interface,
Valves 32, 34, 36A, 37A, 36B, 37B, 36A ', 37A', 36
And a drive circuit for driving the actuator 44.

The ROM stores control programs and various maps required for traction control, and the RAM is provided with various memories required for executing control.

Bad Road Determination Next, a bad road determination procedure in this embodiment will be described.

FIG. 3 is a flowchart showing a rough road determination procedure.
In steps 1 and 2, the control unit UTR detects the left front wheel rotation speed WFL and the right front wheel rotation speed WFR. Next, in step 3, the rotational accelerations DWFL and DWFR of the left and right wheels are obtained based on the front left wheel rotational speed WFL and the front right wheel rotational speed WFR.

Left front wheel acceleration DWFL is obtained by subtracting the front left wheel speed WFL _n-1 of the previous from the current left wheel speed WFL _n.

The DWFL = WFL _n -WFL _n-1 The value to the offset correction, determine the appropriate left front wheel acceleration. That is, This offset correction is performed by subtracting the vehicle acceleration from the wheel acceleration. In this case, in the above equation, the vehicle acceleration is represented by (WFL _n −WFL _n−4 ) / 4. Since the vehicle body starts to move with a delay with respect to the wheels, the offset correction is performed in consideration of the delay. The delay corresponds to approximately four cycles of the rough road determination flow in the present embodiment (flow processing cycle of 14 msec, delay of about 56 msec with respect to the vehicle body wheels). Therefore, in this example, the average of the actual wheel accelerations up to four cycles before the present time is set as the vehicle body acceleration.

 The right front wheel acceleration DWFR is calculated in a similar procedure.

Next, the control unit UTR determines whether or not the timer AKRTM is greater than or equal to a predetermined value, that is, a predetermined time (in this example,
0.7 seconds) (step 4), and if not, whether the absolute value of the left front wheel acceleration DWFL obtained in step 3 is equal to or greater than the reference value THREG for performing rough road determination. It is determined whether it is (step 5).

In this case, in this example, the control unit UTR uses the reference value THREG
Is changed.

Also, the reference value THREG is changed depending on the vehicle speed.

When the ABS control is being performed, the control unit UTR is set to the reference value THRE.
Set G to 1.50g. If you are not under ABS control,
When the vehicle speed is 80 km / h or more, the reference value THREG is set to 0.71 g, and when the vehicle speed is less than that, the reference value is set to 0.57 g.

Next, the control unit UTR counts the number of times the left front wheel acceleration DWFL exceeds the reference value THREG by using the counter AKROL. In this case, the counter AKROL is the left front wheel acceleration DWFL
Is counted only when there is a fluctuation in the amplitude that exceeds both the positive and negative values of the reference value THREG (steps 6, 7, 8).
And 9).

The control unit UTR also counts the number of times the right front wheel acceleration DWFR exceeds the reference value THREG by the counter AKROR in the same manner (steps 10 to 14). Then, the timer AKRTM is added (step 15), and the process returns to step 1.

In the present example, the processing in which steps 1 to 15 are defined as one cycle is executed every 14 microseconds. Therefore, when 50 cycles are performed, the determination in step 1 is YES, and the routine in step 16 is executed.

In the flow shown in FIG. 4, the control unit UTR determines whether the ABS control is being performed (step 17). If this determination is YES, that is, if the ABS control is being performed, the control unit UTR determines the values of the counters AKROL and AKROR, and if any of them exceeds a predetermined value (14 times in this example), the control unit UTR The road is determined and the rough road is corrected (steps 18, 1
9). Specifically, the control is performed by changing control conditions for performing traction control, ABS control, and the like, for example, a target slip ratio (step 20).

If ABS control is not being performed, the above counter AKR
The OL and AKROR values are determined, and if any of the values exceeds a predetermined value (10 times in this example) (steps 21 and 22), the road is determined to be a rough road and a rough road correction is performed.

After executing the processing of FIG. 4 in step 16, the control unit UTR resets the values of the counters AKROL and AKROR and the timer AKRTM (step 23). Therefore, in order to perform the rough road correction, the counter AK
It is necessary that the values of ROL and AKROR reach a predetermined number within a fixed time while the processing of FIG. 3 is repeated 50 times (that is, 0.7 seconds).

Slip control Traction control and ABS as examples of slip control
Control. The traction control is designed to efficiently transmit the power of the drive wheels to the road surface,
This is for maintaining the slip ratio at a desired value.

In the vehicle of the present embodiment, the traction control is performed by controlling the output of the engine 2 to obtain a desired slip type, and controlling the slip ratio by controlling the braking force of the wheels 1RR and 1RL. To achieve the slip rate brake control.

The ABS control is performed in order to prevent the wheel from being locked due to excessive braking force acting on the wheel during braking, thereby preventing the braking effect from deteriorating. The braking force is controlled so as to converge on the set target slip ratio. For this purpose, in the ABS control, the hydraulic pressure of the braking device is controlled so as to periodically reduce the braking force on the wheels.

The ABS control and the traction control brake control are the same in that the braking force is controlled so that the slip ratio converges to the target value.However, in the ABS control, the traction is controlled so that the braking force is periodically reduced. The control is different in that control is performed so that a braking force is applied.

Note that the target slip ratios for the above-described slip ratio brake control and the slip ratio engine control are determined according to, for example, a road surface friction coefficient μ, a vehicle speed, an accelerator opening, a steering angle, and a running mode of a suspension such as sporty or hard. .

Next, the contents of the slip control by the control unit UTR will be described with reference to FIG.

In FIG. 5, the target slip ratio for engine control of the drive wheel is indicated by SET, and the target slip ratio for brake control of the drive wheel is indicated by SET. The target slip ratio SET for engine control and the target slip ratio SBT for brake control are determined according to the wheel speed WFN of the driven wheels. Note that SBT is set to a value larger than SET.

Now, until time point t ₁ before, a large slip on the drive wheels has not occurred, the engine control is not performed, thus the sub-throttle valve 45 is Cage Contact fully opened, the throttle opening degree (both the throttle valve 43 , 45, which corresponds to the opening of the throttle valve with the smaller opening) Tn corresponds to the main throttle opening TH · M, and it is the accelerator opening (the opening of the accelerator pedal. Therefore, when the accelerator pedal is fully depressed, it is fully opened).

t ₁ time, the slip ratio of the driving wheels, is started slip control by the engine control when a target slip ratio SET for the engine control, the throttle opening Tn by closing the sub-throttle valve 45 by controlling the actuator 44 Is reduced all at once to the lower limit control value SM. Then, after the throttle opening degree Tn is once set to SM, the opening degree TH · S of the sub-throttle valve 45 is feedback-controlled so that the slip ratio of the drive wheels becomes the engine control target slip ratio SET. When the engine control is started in this way, the sub-throttle valve opening TH · S becomes smaller than the main throttle valve opening TH · M, and thus the throttle opening Tn becomes the sub-throttle valve opening TH · S. .

If a sufficient slip rate lowering effect cannot be obtained by the above engine control alone, the slip rate continues to increase,
equal to or greater than the target slip ratio SET for the brake control in t ₂ time.

t When the slip ratio of the driving wheels at _two time points becomes equal to or greater than the target slip ratio SBT for controlling brake, drive wheel brake 21RR, 21R
Brake fluid pressure is supplied to L, and slip control by both engine control and brake control is started. The brake fluid pressure is feedback-controlled such that the slip ratio of the drive wheels becomes the brake control target slip ratio SBT.

t ₃ time, the slip ratio of the driving wheels is less than the target slip ratio SBT for controlling brake, the brake fluid pressure is the pressure reduction, the slip control is terminated by the brake control eventually become the brake fluid pressure is zero. However, the slip control by the engine control is still continued.

The above-described slip ratio brake control is performed independently on the left and right sides, for example, based on the slip ratios S _L and S _R of the left and right drive wheels. Further, the engine control, for example, the slip ratio S _L of the left and right driving wheels is made based on the greater of the slip ratio S _E of S _R. Incidentally, the slip ratio S _L, S _R, in the control unit UTR, based on the wheel speed signals from the wheel speed sensors 63 to 66, is calculated according to the following equation.

Where, VK _L : rotational speed of left drive wheel VK _R : rotational speed of right drive wheel VJ: average value of rotational speeds of left and right driven wheels Note that the slip ratio is always calculated based on the above formula. It is not necessary, and any value may be used as long as the value substantially indicates the slip state of the wheel. For example, a value obtained by simply subtracting the driven wheel speed from the driving wheel speed may be used.

Limitation of Target Slip Rate Referring to FIG. 6, there is shown a flow of slip control when limiting the target slip rates SET and SBT.

First, the control unit UTR determines whether the vehicle is braking, based on whether the ABS control is being performed or the brake pedal is being operated (step S1). If the vehicle is not braking, it is determined whether the vehicle is accelerating based on whether the front left wheel rotation speed WFL or the front right wheel rotation speed WFR is increasing (step S2). If the vehicle is not braking or accelerating, it is further determined whether or not a deceleration exceeding the maximum deceleration that can occur at the gear stage of the vehicle has occurred (step S3). This deceleration is a predetermined value (in this example, a decrease in the front left wheel speed WFL or the front right wheel speed WFR).
0.15km / h, equivalent to an acceleration of almost 0.6g). In this determination, if the detected deceleration does not exceed the maximum deceleration, that is, the predetermined value of the wheel speed change, the above-described normal slip control is performed.

When the vehicle is not braking and is not accelerating, such as when the determination in step S3 is YES, that is, the traveling state in which the detected deceleration of the driven wheel exceeds the maximum deceleration is, for example, in deep snow. This may occur when traveling, or when traveling in a mud or the like.
In the above slip control, the target slip ratio SBT, SET
Is set based on the detected deceleration, so even if the detected deceleration exceeds the maximum deceleration, a lower value is set according to the magnitude of the deceleration. Will be done. However, in this case, the deceleration generated in the driven wheels does not correspond to the actual vehicle speed. The value will be set. The slip rate engine control or the slip rate brake control is performed toward the unreasonably low target slip rate SBT, SET, causing the brake fluid pressure to rise rapidly or the engine output to drop sharply, causing the vehicle to stall. That happens. In the control of this example, when the deceleration detected as described above exceeds the preset maximum deceleration of the vehicle, the target slip ratio SB
T and SET are restricted so as not to be unduly lowered in accordance with the detected value of the deceleration (step S4).

In this case, the control unit UTR sets the target slip ratios SBT (k) and SET (k) at the time of the current execution of the routine to the target slip ratios SBT (k-1) and SET (k) at the time of the previous execution.
If the change of the wheel speed decreases beyond the predetermined value (0.15 km / h) from the value of -1), the calculated value SBT at the time of this execution is used.
(K), the predetermined value (0.15 km / m) from the calculated value SBT (k-1) and SET (k-1) of the previous execution without using SET (k).
h) Subtract the value obtained by subtracting the target slip ratio SBT, SET
To be adopted.

 That is, the target slip rates SBT and SET are set as SBT (k) = SBT (k−1) −0.15 km / h SET (k) = SET (k−1) −0.15 km / h.

As described above, in this example, when the detected value of the deceleration of the driven wheel exceeds the maximum deceleration of the vehicle, the target slip rates SBT and SET are set to predetermined values (0.15 km / h) from the values at the time of the previous execution. Is not set to a value smaller than the value obtained by subtracting.

Next, the control unit UTR updates the wheel speed and ends this routine (step S5).

Bad Road Correction in Traction Control Next, a specific example of bad road correction in the traction control will be described in detail with reference to FIG.

In the traction control, first, in step 24, it is determined whether or not the accelerator opening is equal to or more than a predetermined value.

If the accelerator opening is equal to or more than a predetermined value (for example, 50%), the process proceeds to step 25, and it is determined whether at least one of the left and right wheels is on a rough road.

If none of the roads is determined to be bad in step 25, the process proceeds to steps 26 and 27, and normal traction control is performed. That is, the target slip ratio STA (SET, SBT in the above embodiment) is set to a normal target slip ratio, and slip control is performed based on the normal target slip ratio.
Alternatively, the control start threshold value VSPA is set when performing the slip control, and when the slip ratio reaches the VSPA (which is set to a value larger than the target slip ratio STA), the slip control is started to reduce the slip ratio. When performing control so as to reach the target slip ratio STA, the control start threshold value VSPA is set to a normal control start threshold value and the VSPA
Is performed on the basis of the slip control.

On the other hand, if it is determined at step 25 that any one of the roads is a rough road, the process proceeds to steps 28 and 29 to perform traction control after correcting the rough road. That is, the target slip rate STA of the slip rate engine control is set to a slip rate STA ₁ larger than the normal target slip rate, or the control start threshold VSPA is set to a VSPA ₁ larger than the normal control start threshold. And the slip control is performed based on these.

In the above rough road correction, both the STA and the VSPA may be increased, or one of them may be increased. If there are STAs and VSPAs for engine control and brake control, both engine control and brake control may be increased, or one of them may be increased.
In addition, as shown in FIG. 5, the brake control target slip ratio may be increased by correction of a bad road (SBT → SBT ₁ ).

On the other hand, if the accelerator opening is smaller than the predetermined value in step 124, the process proceeds to step 30, where it is determined whether both left and right wheels have been determined to be rough roads.

And if none of them is bad road,
Proceed to 31 and 32, and perform normal traction control in exactly the same manner as in steps 26 and 27.If both wheels are determined to be on a rough road, proceed to steps 33 and 34, and proceed exactly as in steps 28 and 29. In the same manner, traction control is performed after correcting the rough road.

Bad Road Correction in ABS Control Next, bad road correction in the ABS control will be described.

In the case of the slip control as the ABS control, the only difference is that the brake control of the slip control as the traction control is to appropriately increase the brake fluid pressure, whereas the brake control is to appropriately reduce the brake fluid pressure. The basic device configuration and control are the same as those in the case of the slip control as the traction control (except for the control unit UT
A stores a control program for ABS control, various maps, and the like, and controls the brake fluid pressure for the front wheels as well as for the rear wheels. ). Therefore, the description of the specific device and the ABS control itself is omitted, and a specific example of the rough road correction in the ABS control will be described below with reference to FIG.

In the rough road correction of the ABS control, it is determined whether or not both wheels are rough roads in step 35, and if neither is a rough road, the process proceeds to steps 36 and 37, and normal ABS control is performed. . That is, a normal target slip ratio is set as the target slip ratio S for the ABS control, and the slip control is performed based on the normal target slip ratio.

If both of the wheels are on a rough road, the process proceeds to steps 38 and 39 to perform slip control after correcting for a rough road. That is, the target slip rate is changed to the normal target slip rate S
Set small S ₁ than the smaller the target slip ratio S ₁
Is performed based on the slip control.

(Effects of the Invention) According to the present invention, in a running state in which a change in wheel speed is detected beyond the maximum deceleration that can occur in the vehicle, the target slip ratio decreases in accordance with the deceleration. Is restricted. Therefore, appropriate slip control can be performed regardless of the detected value of the wheel speed of the driven wheel.

In this case, since the acceleration of the wheel speed can be accurately obtained, the rough road correction in the slip control can be appropriately performed.

[Brief description of the drawings]

1 is a block diagram schematically showing an embodiment of the present invention, FIG. 2 is an overall system diagram specifically showing an embodiment of the present invention, and FIG. 3 is a rough road correction control in the case of traction control. Flowchart, Fig. 4 is a flowchart showing bad road determination, Fig. 5 is a time chart showing the form of traction control, Fig. 6 is a flowchart of control for limiting the target slip ratio, and Fig. 7 is a bad road in traction control. FIG. 8 is a flowchart showing the control of the correction, and FIG. 8 is a flowchart showing the rough road correction control in the case of the anti-skid control. 100: Drive wheel speed detecting means 200: Driven wheel speed detecting means 300: Slip rate calculating means 400: Target slip rate setting means 500: Control means 600: Limiting means A: Vehicle, 1RL, 1RR … Drive wheel, 1FL, 1FR… Driver wheel, 2… Engine, 3 …… Automatic transmission, 4… Propeller shaft, 5… Differential gear device, 6L, 6R… Drive shaft, 11… Torque converter 12 Multi-speed gear mechanism 13a, 13b Solenoid UAT Control unit for automatic transmission 43 Main throttle valve 44 Actuator 45 Sub-throttle valve 61 Main throttle Valve opening sensor, 62 …… Sub throttle valve opening sensor, 63 …… Vehicle speed sensor, 63, 21FR-21RR …… Brake, 22FR-22RR …… Caliper, 23FR-23RR, 28, 30, 33 …… Piping, 25 ... brake pedal, 26 ... booster 27 ... Master cylinder, 29 ... Pump, 32, 34 ... On-off valve, 35 ... One-way valve, 36A, 37A ... Electromagnetic on-off valve, 41 ... Intake passage, 42 ... Accelerator pedal, 64-67 ... Wheel speed sensor, 68 ... Accelerator opening sensor, 69 ... Yaw rate sensor, 70 ... Shift sensor, 71 ... Steering angle sensor.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Fumio Kageyama 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-62-265430 (JP, A) JP-A-63 JP-20121 (JP, A) JP-A-3-121966 (JP, A) JP-A-3-281469 (JP, A) JP-A-2-41963 (JP, A) JP-A-4-203332 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 29/00-29/06 B60K 41/00-41/28 B60K 28/16 B60T 8/32-8/96

Claims (1)

(57) [Claims] 1. A driving wheel speed detecting means for detecting respective speeds of driving wheels, a driven wheel speed detecting means for detecting respective speeds of driven wheels, a driving wheel speed detecting means and a driven wheel speed detecting means. A slip ratio calculating unit that calculates a slip ratio of the driven wheel based on the detected value of the target wheel; a target slip ratio setting unit that sets a target slip ratio based on the wheel speed of the driven wheel; Control means for controlling the engine output or the braking force so as to converge, and the target slip ratio is reduced when a decrease in the wheel speed of the driven wheel exceeding the maximum deceleration that the vehicle can generate during normal traveling is detected. A traction control device for a vehicle, comprising: a restriction means for restricting a decrease in response to the change.