JP3299581B2 - 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 slip control apparatus for a vehicle, and more particularly to an improved technique for performing a correction in consideration of a difference in wheel speed between an inner drive wheel and an outer drive wheel at the time of turning.

[0002]

2. Description of the Related Art Conventionally, during acceleration of a vehicle, in order to prevent the drive wheels from slipping due to excessive driving torque and deteriorating the acceleration, the slip amount of the drive wheels is detected and the slip amount of the drive wheels is detected. as a target value, controls the application of braking force to the engine output and the wheel (lowering the engine output, or the braking force increased to a) traction control technology thus constructed is generally commercialized, also, anti-skid Not a few devices include a control device and a traction control device (for example, see Japanese Patent Application Laid-Open No. 1-197160). On the other hand, when the vehicle is turning, the wheel speed of the outer drive wheels is higher than the wheel speed of the inner drive wheels,
The apparent slip amount of the outer driving wheel becomes large, and it is not preferable to perform the slip control based on the apparent slip amount. Therefore, Japanese Patent Application Laid-Open No. Sho 62-60937 discloses a technique for correcting the slip amount in consideration of a wheel speed difference generated between an inner driving wheel and an outer driving wheel when the vehicle turns, when performing traction control. Have been.

[0003]

When a correction is made in consideration of the difference between the wheel speeds of the inner and outer driving wheels, the correction is made using the detected steering angle detected by a steering angle sensor. However, since there is a slight delay with respect to a change in the detected steering angle, there is a problem that the correction in consideration of the wheel speed difference is executed earlier than the actual turning behavior of the vehicle.
An object of the present invention is to eliminate a time lag between a correction taking into account a wheel speed difference and an actual turning behavior of a vehicle.

[0004]

Means for Solving the Problems] slip control device for a vehicle according to claim 1, a wheel speed detecting means for detecting a wheel speed of the four wheels of the vehicles, the left on the basis of the detection result of the wheel speed detecting means < A slip amount calculating means for calculating a slip amount of each of the right driving wheels, a steering angle detecting means for detecting a steering angle of the vehicle, and a steering angle signal detected by the steering angle detecting means are smoothed. and smoothing processing means, based on the smoothing process has been steering angle signal by the smoothing processing means, Starring in the slip amount calculation means
The slip amount of calculation has been driving wheels, and correction means for performing correction in consideration of the wheel speed difference of the inner driving wheel and outer driving wheel during a turn, based on the slip amount that has been corrected by said correction means
To prevent the drive wheels from slipping on the road surface.
Traction control means for controlling the engine output .

Here, the smoothing processing means is configured to increase the degree of smoothing as the vehicle speed increases (claim 2), and the smoothing processing means increases the lateral acceleration acting on the vehicle. (Claim 3), the smoothing means increases the smoothing degree in accordance with an increase in the steering angle (claim 4), etc. It can be configured in various aspects.

According to a fifth aspect of the present invention, there is provided a vehicle slip control device for detecting a wheel speed of four wheels of a vehicle, and a left and right driving wheel based on a detection result of the wheel speed detecting device. a slip amount calculating means for calculating a slip amount of each steering of the vehicle
And the steering angle detecting means for detecting a corner based on the detected steering angle signal by the steering angle detecting means, in the slip amount calculation means
Correction means for correcting the calculated slip amount of the drive wheel in consideration of the wheel speed difference between the inner drive wheel and the outer drive wheel at the time of turning; and a correction means based on the slip amount corrected by the correction means.
To prevent the drive wheels from slipping on the road surface.
A traction control means for controlling the engine output; and a delay means for delaying the timing of the correction by the correction means in accordance with an increase in the degree of turning of the vehicle, in comparison with real time.

[0007]

According to the first aspect of the present invention, the wheel speed of the four wheels of the vehicle is detected by the wheel speed detecting means, and the slip amount calculating means is based on the wheel speeds of the four wheels. calculating a slip amount of the drive wheel each of the right and left, the smoothing process unit, the moderation of the steering angle signal detected by the steering angle detecting means and processing, correction means, based on the smoothing process steering angle signal Then, the slip amount of the left and right drive wheels is corrected in consideration of the wheel speed difference between the inner drive wheel and the outer drive wheel during turning. And the traction control means is the correction means
On the road surface based on the slip amount corrected by
The engine output to suppress the drive wheel slip
I do. Therefore, by performing the correction in consideration of the wheel speed difference between the inner drive wheel and the outer drive wheel using the smoothed steering angle signal, the correction is performed earlier than the actual turning behavior of the vehicle. Thus, the timing of the correction can be made to coincide with the actual turning behavior of the vehicle, and the slip control can be appropriately performed.

Here, the smoothing processing means is configured to increase the smoothing degree in accordance with the increase of the vehicle speed, the lateral acceleration or the steering angle, as in the second to fourth aspects. This is because the delay time of the actual turning behavior of the vehicle increases as the lateral acceleration and the steering angle increase.

[0009] In the slip control apparatus for a vehicle according to claim 5, the wheel speed detecting means detects the wheel speed of the four wheels of the vehicle, the slip amount calculation means, the detection result of the wheel speed detecting means
Calculating a slip amount of the drive wheel each of the right and left based on the steering
The angle detecting means detects the steering angle of the vehicle, and the correcting means detects the slip based on the steering angle signal detected by the steering angle detecting means.
The slip amount of the driving wheel calculated by the amount calculating means is corrected in consideration of a difference in wheel speed between the inner driving wheel and the outer driving wheel at the time of turning, and the traction control means corrects by the correcting means.
Based on the calculated slip amount, the drive wheel slips on the road surface.
The engine output is controlled so as to suppress the lip, and the delay unit delays the timing of the correction by the correction unit in accordance with an increase in the turning degree of the vehicle. In this way, by delaying the timing of the correction by the correction means in accordance with the increase in the degree of turning of the vehicle, the same operation and effect as in claim 1 can be achieved.
The effect is obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, in the vehicle 1, left and right front wheels 2a and 2b are driving wheels, and left and right rear wheels 3a and 3b are driven wheels. A V-type 6-cylinder engine 4 is mounted on the front part of the vehicle body, and the driving torque from this engine 4 is transmitted to the left front wheel 2a via the left driving shaft 7a via the automatic transmission 5 and the differential device 6 and to the right driving shaft 7b. The transmission is transmitted to each of the right front wheels 2b via the right wheel.

A control device 8 for executing fuel injection control and ignition timing control of the engine 4 and slip control (corresponding to engine traction control) of the vehicle is provided.
The control device 8 is provided with an engine control unit for executing fuel injection control and ignition timing control, and a slip control unit for executing slip control. Also, as sensors,
An engine speed sensor for detecting the speed of the engine 4;
Steering angle sensor 10 for detecting the steering angle of the steering wheel, the four wheels 2
a, 2b, 3a, 3b, brake sensors for detecting the braking state of the four wheels 2a, 2b, 3a, 3b, and wheel speed sensors 9a, 9b, 9c, 9d for detecting the wheel speed of the four wheels 2a, 2b, 3a, 3b, Is supplied to the control device 8.

The control device 8 includes an input interface for receiving detection signals from the sensors, two microcomputers including a CPU, a ROM, and a RAM, an output interface, and a drive for an igniter and a fuel injector. The control program for the fuel injection control and the ignition timing control and tables and maps associated therewith are stored in advance in the ROM of the microcomputer of the engine control unit. The ROM stores a control program for slip control described later and various tables and maps for this slip control in advance.
M is provided with various memories and soft counters.

The slip control executed by the slip control unit of the control device 8 will be briefly described. First, the actual turning radius R is calculated using the detection signals from the sensors.
r, a turning radius corresponding to a steering angle, a vehicle speed V (vehicle speed), a road surface friction coefficient μ, a lateral acceleration G is determined, and a slip determination threshold value and a control target value T are determined based on the lateral acceleration G. Is calculated so as to be lower as the lateral acceleration G increases. Thereafter, calculation of slip amount, determination of slip, setting of control target value T, calculation of control level FC for adjusting engine output, and the like are executed, and a control signal of slip control is output for fuel control and ignition timing control. I do.

In the slip control, the slip amount is calculated by taking into account the wheel speed difference between the inner drive wheel and the outer drive wheel during the turning operation when calculating the slip amount.
The steering angle signal detected by the steering angle sensor 10 is smoothed, and the slip control calculation process is performed using the smoothed steering angle signal, so that the slip control has no time lag with the actual turning behavior of the vehicle. Is realized.

Hereinafter, slip control (engine traction control) executed in the slip control unit will be described with reference to FIG. 2 and subsequent drawings. However, the symbol Si in the figure
(I = 1, 2, 3,...) Indicates each step. The slip control is started when the engine 4 is started, and various detection signals such as the detected steering angle θ are read from the sensors (S1). Next, in S2, a detected steering angle smoothing process for smoothing the steering angle signal detected by the steering angle sensor 10 is executed.

This smoothing process is executed by processing the data of the detected steering angle θ by the following general formula of the smoothing process. θ (k) = θ (k−1) + [θ (k) −θ (k−1)] / K (1) where θ (k) is the current detected steering angle and θ (k−1) Is the previous detected steering angle, and K is a positive predetermined averaging constant that is somewhat large. As the averaging constant K increases, the degree of averaging increases. Therefore, the smoothing constant K increases as the vehicle speed V increases, increases as the lateral acceleration G during turning increases, and detects the steering angle θ.
Is set so as to increase with an increase in. That is,
Assuming that α is a predetermined coefficient, K = α · V · G · θ (k) is set, the vehicle speed V is calculated in the same manner as described in S3, and the lateral acceleration G is described in S4. Is calculated in the same manner as in the above, a smoothing constant K is calculated using the current detected steering angle θ (k), and the smoothed constant K is applied to the equation (1) to obtain the current detected steering angle θ. (K) is calculated. However, in the following description, the steering angle θ is the current detected steering angle θ (k) subjected to the above-described smoothing processing.

Next, in S3, an operation for obtaining the actual turning radius Rr, the turning radius corresponding to the steering angle Ri, the vehicle speed V, and the road surface friction coefficient μ is executed. The actual turning radius Rr is determined by the wheel speed sensor 9.
c, 9d detected wheel speed V of driven wheels 3a, 3b
1, V2 is calculated by the equation (2). Here, Td is the tread (for example, 1.7 m) of the vehicle.

Rr = Min (V1, V2) × Td ÷ | V1−V2 | + 0.5Td (2) The turning radius corresponding to the steering angle Ri substantially corresponds to the turning radius in the neutral steering, which is the current turning radius. Based on the absolute value of the detected steering angle θ, it is obtained by linear interpolation from the table shown in Table 1 below.

[0019]

[Table 1]

The vehicle speed V is determined by the wheel speed sensors 9c, 9
wheel speeds V1 and V2 of the driven wheels 3a and 3b detected from d.
Is calculated as the higher value of The road friction coefficient μ is calculated based on the vehicle speed V and the acceleration Vg. For the calculation of the road surface friction coefficient μ, a timer of 100 msec count and a timer of 500 msec count are used, and 100 msec from the start of the slip control until 500 msec elapse when the vehicle body acceleration Vg does not become sufficiently large.
From the change in the vehicle speed V for 100 msec for each c, the following (3)
The vehicle acceleration Vg is obtained by the following equation.
After 500 msec elapses when the
From the change in the vehicle speed V for 500 msec every msec, the vehicle body acceleration Vg is obtained by the following equation (4). In addition, V (k)
Is the current time, V (k-100) is 100 msec before, V
(K-500) is each vehicle speed before 500 msec, and K
1, K2 are predetermined constants, respectively.

Vg = K1 × [V (k) −V (k−100)] (3) Vg = K2 × [V (k) −V (k−500)] (4) The road surface friction coefficient μ is: The vehicle speed V obtained as described above,
The calculation is performed by three-dimensional interpolation from the μ table shown in Table 2 using the vehicle body acceleration Vg.

[0022]

[Table 2]

Next, in step S4, the lateral acceleration G and the lateral acceleration corresponding correction coefficient k are calculated. This routine will be described with reference to FIG. The lateral acceleration G is determined by the turning radius and the vehicle speed V. To determine the lateral acceleration G, the actual turning radius Rr and the turning radius corresponding to the steering angle Ri are selectively used. Based on the road surface condition and the driving condition, the magnitude of the tendency to deviate from the travel line at the steering angle-corresponding turning radius Ri when the vehicle turns is determined, and when the tendency is large, the steering angle-corresponding turning radius Ri is selected. When the tendency is not large, the actual turning radius Rr is selected.

In the flowchart of FIG. 3, when the absolute value of the current detected steering angle θ is equal to or greater than a predetermined value θo, the vehicle speed V is equal to or greater than a predetermined value Vo, and the road surface friction coefficient μ is equal to or less than a predetermined value μo, the steering angle Lateral acceleration G using the corresponding turning radius Ri
(S41 to S44), and when the above conditions are not satisfied, the lateral acceleration G is calculated using the actual turning radius Rr (S41 to S43, S45), and then the correction coefficient k based on the lateral acceleration G is calculated. (S46).

The lateral acceleration G is calculated from the vehicle speed V and the turning radius R (steering angle-corresponding turning radius Ri or actual turning radius Rr) by the following equation. G = V × V × (1 / R) × (1/127) (5) Next, in S46, a correction coefficient k based on the lateral acceleration G is calculated.
Is calculated from the preset correction coefficient table in Table 3.

[0026]

[Table 3]

Next, in S5 of the flowchart of FIG. 2, a threshold value for slip determination is set. The threshold value for slip determination is set to a basic threshold value × a correction coefficient k, and the basic threshold value is a basic threshold value table 1 in Table 4 using the vehicle speed V and the road surface friction coefficient μ as parameters. Slip control start) or basic threshold table 2 in Table 5
(For continuation of slip control) is calculated by three-dimensional interpolation. The control target basic threshold value table 1 in Table 4 indicates whether or not to start slip control, and the control target basic threshold value table 2 in Table 5 indicates This is to determine whether or not the slip control should be continued.

[0028]

[Table 4]

[Table 5]

[0029]

[Table 6]

[Table 7]

Next, in S6, the calculation of the slip amount is executed. The calculation of the slip amount will be described with reference to the flowchart of FIG. 4. The apparent slip amounts SL and SR of the front wheels 2a and 2b as the left and right driving wheels are calculated from the wheel speeds Vha and Vhb of the left and right front wheels 2a and 2b. V is subtracted from each other to calculate (S51), and then it is determined whether or not the vehicle is turning based on the detected steering angle θ (S5).
2) When the vehicle is turning, S5 is determined in order to obtain the slip amount in consideration of the wheel speed difference between the inner front wheel and the outer front wheel during the turning.
At 3, the apparent slip amounts SL and SR are corrected. When turning left, SL changes to (SL + k1),
Further, SR is corrected to (SR-k2), and at the time of turning right, SL becomes (SL-k2) and SR becomes (SR-k2).
+ K1).

The above-mentioned k1 is a slip amount correction value preset in Table 6, and the above-mentioned k2 is a slip amount correction value preset in Table 7. Note that the difference between the correction terms of the left and right drive wheels from k1 and k2 is that the left and right driven wheels (rear wheels) are different.
This is because the higher wheel speed is used as the vehicle speed V (vehicle speed) without using the average of the wheel speeds V1 and V2. After this correction processing, the flow shifts to S54, and also when it is determined in S52 that the vehicle is not turning, the flow also shifts to S54. Next, S
At 54, the average slip amount SAv is
Calculated from the average value of L and SR, and then the maximum slip amount S
Hi is calculated from the higher value of the slip amounts SL and SR (S55). Next, in S7 of FIG. 2, a slip determination is performed. In the slip determination, when the following equation (6) is satisfied based on the maximum slip amount SHi and the slip determination threshold value, it is determined that the slip control is necessary, and the slip flag SFL is set to 1.

SHi ≧ Slip Determination Threshold (6) In this case, the non-control state (CFL = 0) is determined as the slip determination threshold in step S134 of the flowchart of FIG. 5 showing the routine of S10. When the slip control is being performed (CFL = 1), the control target basic threshold for continuation in Table 5 is used. Is done.

[0033]

[Table 8]

[Table 9]

Next, in S8, it is determined whether or not the flag CFL = 1, and if CFL = 0 (the slip control is not being executed), the routine immediately returns. On the other hand, in S8, CFL
= 1 (during execution of slip control), S9
Move to. Next, a control target value T is set in S9. The control target value T is the front wheel 2a, with a target value as a slip amount of 2b, the control target basic value table of Table 8 and the vehicle speed V and the road surface friction coefficient number μ as a parameter 3
The control target basic value and the correction coefficient k obtained by the dimension complementation are calculated by the following equation. Control target value T = Control target basic value × k (7)

Next, a control level FC is calculated in S10. For this control level FC, a basic control level FCB is determined based on the deviation EN of the average slip amount SAv from the control target value T and the rate of change DEN, and a feedback correction of the previous value FC (k-1) is made. And the first correction is taken into account, and set in the range of 0 to 15. The initial correction is (+5) until the rate of change DSAv of the average slip amount SAv becomes zero for the first time.
The time until TFL becomes 0 is (+2). The routine of S10 will be described with reference to the flowchart of FIG. First, in S131, the deviation EN and the deviation change rate DEN are calculated by the following equations (8) and (9), respectively. Deviation EN = SAv (k) −Control target value T (8) Deviation change rate DEN = DSAv = SAv (k) −SAv (k−1) (9)

Next, in S132, the basic control level FCB is calculated from the basic control level table shown in Table 9 based on the deviation EN and the deviation change rate DEN. Next, S
At 133, a feedback correction for adding the previous control level FC (k-1) to the current control level FC (k) is performed, then a slip control determination is performed at S134, and then a first slip control determination is performed at S135. Then, in S136, an initial correction amount for forcibly increasing the control level from when the slip of the front wheels 2a, 2b is first determined until the first slip determination is eliminated is calculated.

The routine for determining the slip control in S134 will be described with reference to the flowchart of FIG. First, in S140, it is determined whether or not the slip flag SFL = 1 and the vehicle is in the non-braking state. When these conditions are satisfied, the control flag CFL indicating that the slip control is being performed is set in S141, and the process proceeds to S135. I do. On the other hand, when No is determined in S140, in S142, it is provided in the slip control unit,
The count value t1 of the first counter that counts the duration of the signal of the slip flag SFL = 0 and the count of the second counter that counts the duration that FC ≦ 3 and DSAv ≦ 0.3g are satisfied The value t2 is read out and the count value t1 is 1000 msec or more (S143: Yes), or the count value t2 is 500
If it is longer than msec (S145: Yes), the control flag CFL is reset, and the routine goes to S135.

The routine for determining the first slip control in S135 will be described with reference to the flowchart of FIG.
First, in S150, the current control flag CFL is set.
(K) = 1 and the previous control flag CFL (k-1) =
If these conditions are satisfied, it is determined in step S151 that the initial flag STFL is set, and the flow shifts to step S136. On the other hand, when No is determined in S150, it is determined in S152 whether or not the current slip flag SFL (k) = 0 and the previous slip flag SFL (k-1) = 1, and these conditions are set. If the condition is satisfied, the initial flag STFL is reset in S153, and the flow shifts to S136.
When it is determined No in S150 and S152, the process proceeds to S136. In S136 of FIG. 5, based on the first flag STFL signal and the average slip amount change rate DSAv shown in the equation (9), the first correction amount (+2) is determined when STFL = 1 and DSAv <0. Next, in S137, the basic control level FCB is added with the feedback correction of the previous value FC (k-1) and, if there is the first correction, the first correction to add the final control level FCB.
(K) is set in the range of 0 to 15.

Next, in S11 of the flowchart of FIG. 2, a slip control signal is output from the slip control unit to the engine control unit. The control signal includes a control signal for retarding the ignition timing and a control signal for instructing a fuel cut. For the ignition timing, see FIG.
The retard amount according to the control level is determined and output based on the map shown in FIG. In this case, based on the map shown in FIG. 9, the maximum retard amount is limited in a region where the engine speed is high. As for the fuel cut, one of the patterns 0 to 12 in the fuel cut table of Table 10 is selected based on the control level FC. The pattern number increases as the control level FC increases. In addition, the mark x in Table 10 indicates a fuel cut. In this case, as shown in FIG. 10, the fuel cut is limited in a region where the engine speed is low.
Fuel cut prohibition conditions are set for each control level.

[0040]

[Table 10]

Next, the operation of the slip control will be described. As shown in the time chart of FIG. 11, the threshold value for starting the slip control is set to a relatively high threshold value Sh based on the basic threshold value table for starting. Even if it becomes high, the slip control is not started unless the threshold value Sh is exceeded. When the wheel speed of the drive wheel exceeds the threshold value Sh, the slip flag SF
When L is set and the brake is in the inoperative state, the control flag CFL and the initial flag STFL are set and slip control is started.

In the turning operation of the vehicle, when it is determined that the understeer tendency is large, the lateral acceleration G of the vehicle is calculated using the turning radius Ri corresponding to the steering angle, but the turning radius Ri corresponding to the steering angle is the actual turning radius Rr. Therefore, the lateral acceleration G is large, and the correction coefficient k is small, so that the start determination threshold value Sh is low. Therefore, the slip control is started early, and it is possible to suppress the excessive understeer tendency before the drive torque of the drive wheels is reduced early. On the other hand, when the understeer tendency is not large, the lateral acceleration G is calculated using the actual turning radius Rr, so that the slip determination threshold value and the control target value T are accurately corrected to match the actual lateral acceleration. You.

Here, in the straight running of the vehicle, the maximum slip amount SHi is determined from the apparent slip amounts SL and SR of the left and right drive wheels, but during turning, the wheel speed of the outer wheel is higher than that of the inner wheel. growing. Accordingly, when the apparent slip amount of the outer wheel is based on the apparent slip amount, the maximum slip amount SHi may exceed the threshold value Sh.
In the present invention, since the slip amount obtained by subtracting the slip amount correction value k2 from the apparent slip amount of the outer wheel is used, it is possible to prevent the slip control from being started even though the actual slip amount is not large. be able to.

On the other hand, there is a slight delay in the actual turning behavior of the vehicle with respect to the change in the detected steering angle. Therefore, if the detected steering angle is applied to the slip control as it is, the actual turning behavior of the vehicle becomes smaller than the actual turning behavior of the vehicle. The correction that takes into account the difference between the wheel speeds of the inner and outer drive wheels is performed early. In the present invention, in the step S2 in FIG. 2, the detected steering angle θ is smoothed, and the smoothed detected steering angle θ is applied. Can be eliminated. That is, FIG.
As shown in FIG. 2, from the state of the steering angle “0 °”, for example, “20”
0 ° ", the detected steering angle θ is shown by a solid line as shown in the figure.
Since it changes to the delay side as shown by the dotted line, it changes in a state substantially matching the behavior of the wheel speed difference between the inner and outer drive wheels. By increasing the smoothing constant K in accordance with an increase in the turning degree of the vehicle, the calculated steering angle θ and the turning behavior of the vehicle can always be substantially matched.

The average slip amount SAv is calculated based on the slip amount obtained as described above, and the control target value T is calculated as follows.
It is set based on the vehicle speed V and the road surface friction coefficient μ. Then, a deviation E of the average slip amount SAv from the control target value T is calculated.
The basic control level FC is set on the basis of N and the rate of change DEN of the deviation, and the control level FC is obtained by performing an initial correction on the basic control level FC. The ignition timing control and the fuel injection restriction in accordance with the control level are performed. Control is performed. The first flag STFL becomes 0 because the maximum slip amount SH
This is the point in time when i becomes equal to or less than the threshold value Sc for continuation of slip control, at which point the slip control is temporarily stopped. Since the basic value of the continuation threshold value Sc is calculated from the continuation basic value table and set to a relatively low value, the slip can be surely converged.

Even if the higher driving wheel speed becomes equal to or lower than the continuation threshold value Sc, if the state does not continue for one second or longer, the control flag CFL is held in the set state.
With the suspension of the slip control, the wheel speed of the driving wheel increases again, and when it exceeds the continuation threshold Sc, the slip flag SFL is set again and the slip control is restarted. In this case, the first flag STFL is not set, and the first correction of the control level FC is not performed. Accordingly, the control level FC is initially set only at the basic control level based on the deviation EN and the deviation change rate DEN, and thereafter, a value obtained by adding the previous value to the basic control level by feedback correction is set as the control level FC. Go. As described above, when the slip converges and the state where the slip flag SFL is not set for more than one second continues, the control flag CFL
Is reset, and the one-cycle slip control ends.

In the above embodiment, the apparent slip amounts SL and SR of the left and right driving wheels 2a and 2b are corrected in S53 of FIG. 4, but the wheel speeds Vha and Vhb of the driving wheels are adjusted. The correction may be made as follows. When turning left Vha is set to (Vha + k1) and Vhb is set to (Vhb-k
2), respectively, and when turning right Vha is set to (Vha−k2) and Vhb is set to (Vhb + k).
In 1), each is corrected.

Further, as another embodiment, FIG.
Of the left and right drive wheels 2a, 2
By delaying the timing of correcting the apparent slip amounts SL and SR of b, the same operation as the smoothing process can be obtained. Taking the case of performing the correction in S53 of FIG. 4 as an example based on the flowchart of FIG. 13, regarding the slip amount correction values k1 and k2, the current slip amount correction value calculated in real time is k1 (i), k2
(I), and the slip amount correction value k1 (i),
k2 (i), k1 (i-1), k2 (i-1), k1
A buffer for storing (i-2), k2 (i-2),... Is provided.

In the flowchart of FIG.
1, the current slip amount correction values are k1 (i), k2
(I) is calculated and stored in the buffer, and then S252
, The slip amount correction values k1 (i−τ) and k2 (i−τ) before a predetermined time τ shorter than the real time are read from the buffer. The steps of S253 to S257 are the same as the steps of S51 to S55 in FIG. 4, and thus description thereof is omitted. However, in S255, the slip amount correction value k1 (i
−τ) and k2 (i−τ) are used to correct the slip amount. In this manner, by delaying the correction by the slip amount correction values k1 and k2 from the real time by the set time τ, the same operation as the operation by the smoothing process on the detected steering angle θ in the above embodiment can be obtained. However, the set time τ is largely changed according to an increase in the degree of turning of the vehicle, that is, according to an increase in the vehicle speed V, the lateral acceleration G, and the steering angle θ.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of a slip control routine.

FIG. 3 is a flowchart of the step S4 in FIG. 2;

FIG. 4 is a flowchart of step S6 in FIG. 2;

FIG. 5 is a flowchart of the step S10 in FIG. 2;

FIG. 6 is a flowchart of a slip control determination in S134 of FIG. 5;

FIG. 7 is a flowchart of an initial slip control determination in S135 of FIG. 5;

FIG. 8 is a diagram of a map of an ignition retard amount with respect to a control level.

FIG. 9 is a diagram of a map of an ignition retard amount with respect to an engine speed;

FIG. 10 is an explanatory diagram of a fuel cut prohibition region with respect to a control level and an engine speed.

FIG. 11 is an overall operation time chart of the slip control.

FIG. 12 is an operation time chart of a detected steering angle θ and a wheel speed difference between inner and outer drive wheels.

FIG. 13 is a diagram corresponding to FIG. 4 according to another embodiment.

[Explanation of symbols]

 Reference Signs List 4 engine 8 control device 9a, 9b, 9c, 9d wheel speed sensor 10 steering angle sensor FC control level FCB basic control level Sh threshold for starting slip control Sc threshold for continuing slip control

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-4-219434 (JP, A) JP-A-2-38149 (JP, A) JP-A-2-24273 (JP, A) JP-A-2- 77360 (JP, A) JP-A-2-70939 (JP, A) JP-A-2-291458 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 29/00-29 / 06 F02D 41/00-45/00 395 B60K 41/00-41/28

Claims (5)

(57) [Claims] 1. A wheel speed detecting means for detecting a wheel speed of the four wheels of the vehicles, the left and right driving wheels on the basis of the detection result of the wheel speed detecting means
A slip amount calculating means for calculating a slip amount of each, and the steering angle detecting means for detecting a steering angle of the vehicle, and smoothing processing means for processing moderation steering angle signal detected by the steering angle detecting means, wherein the annealing moderation by the processing means processed steering angle signal
Based on, the slip amount of the slip amount driving wheel calculated by the calculating means, and correction means for performing correction in consideration of the wheel speed difference of the inner driving wheel and outer driving wheel during a turn, which is corrected by said correction means Based on slip amount
To prevent the drive wheels from slipping on the road surface.
And a traction control means for controlling a gin output . 2. The vehicle slip control device according to claim 1, wherein the smoothing processing means is configured to increase the smoothing degree as the vehicle speed increases. 3. The vehicle slip control device according to claim 1, wherein the smoothing processing means is configured to increase the smoothing degree in accordance with an increase in the lateral acceleration acting on the vehicle. . 4. The vehicle slip control device according to claim 1, wherein the smoothing processing means is configured to increase a smoothing degree in accordance with an increase in a steering angle. A wheel speed detecting means for detecting a wheel speed of the four wheels of 5. vehicles, left and right drive wheels based on the detection result of the wheel speed detecting means
A slip amount calculating means for calculating a slip amount of each, and the steering angle detecting means for detecting a steering angle of the vehicle based on the detected steering angle signal by the steering angle detecting means, before
The slip amount of the serial slip drive wheels calculated by the calculating means, and correction means for performing correction in consideration of the wheel speed difference of the inner driving wheel and outer driving wheel during a turn, the slip amount that has been corrected by said correction means Based
To prevent the drive wheels from slipping on the road surface.
A traction control means for controlling a gin output; and a delay means for delaying the timing of correction by the correction means from real time in accordance with an increase in the turning degree of the vehicle. .