JPH0270564A - Acceleration slip preventing device for vehicle - Google Patents

Abstract

PURPOSE:To improve the quality of turning through the restraint of the occurrence of a slip at the time of turning, by providing a braking means which conducts the brake of drive wheels in accordance with differences between the carwheel velocities of the drive wheels and a reference carwheel velocity that is made to be the larger carwheel velocity between the carwheel velocities of a pair of follower wheels and which also strengthens the brake force of the inner wheel side at the time of turning. CONSTITUTION:The larger carwheel velocity VR between the carwheel velocity of one follower wheel which is WRR detected by means of the 1st carwheel velocity sensor 13 and the carwheel velocity of the other follower wheel WRL detected by means of the 2nd carwheel velocity sensor 14, is made to be a reference carwheel velocity, and a controlling means 15 conducts the brake of drive wheels WFR, WFL in accordance with differences between this reference carwheel velocity and the carwheel velocities of drive wheels WFR, WFL outputted from the 3rd and 4th carwheel velocity sensors 11, 12, and also, strengthens the brake force of the inner wheel side at the time of turning. Accordingly, turning can be safely made through the restraint of the occurrence of a slip at the time of turning.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an acceleration slip prevention device for a vehicle that improves the turning performance of the vehicle.

(Prior Art) Acceleration slip prevention devices (traction control devices) have been known that prevent slips of drive wheels that occur when a vehicle is suddenly accelerated. In such a traction control device, when acceleration slip of the driving wheels is detected, the slip rate $ is controlled so that the coefficient of friction μ between the tire and the road surface is within the maximum range (shaded range in FIG. 15). Here, the slip rate S is [(VP −V
B)/VF]×100 (percent), where vF is the wheel speed of the driving wheels and VB is the vehicle body speed.

In other words, when a slip of the driving wheels is detected, the wheel speed vF of the driving wheels is controlled by controlling the engine output.
The slip ratio S is controlled to be within the shaded range, and the friction coefficient μ between the tires and the road surface is controlled to be within the maximum range, thereby preventing the drive wheels from slipping during acceleration and improving the acceleration performance of the vehicle. That's what I do.

(Problems to be Solved by the Invention) By the way, a factor that improves the turning performance of an automobile when turning is the lateral force generated in the tires. By increasing this lateral force, cornering force can be increased and turning performance can be improved. This lateral force is caused by the slip ratio S, as shown by A in Figure 15.
is gradually decreased as the value increases. Therefore, the friction coefficient μ
At the position where the maximum range is reached, there is a problem in that the turning performance cannot be fully demonstrated because the lateral force is insufficient.

The present invention has been made in view of the above points, and its purpose is to control the acceleration of a vehicle to increase the effort (during turns) to suppress the occurrence of slip during turns and improve turning performance. An object of the present invention is to provide a slip-slip prevention device.

[Structure of the invention] (Means and effects for solving the problem) The driving wheel speed and the driven wheel speed are detected, and the slippage and bump according to the difference between the driving wheel speed and the driven wheel speed are calculated, and this slip amount is calculated. In the acceleration slip prevention device for a vehicle configured to reduce the slip of the driving wheels by controlling the output torque of the engine and braking the driving wheels accordingly, the first device detects the wheel speed of one of the driven wheels of the vehicle. a wheel speed sensor; a second wheel speed sensor that detects the wheel speed of the other driven wheel of the vehicle; a third wheel speed sensor that detects the wheel speed of one driving wheel of the vehicle; a fourth wheel speed sensor that detects the wheel speed of the wheel, and a wheel speed of one driven wheel detected by the first wheel speed sensor and the second wheel speed.
The wheel speed of the driving wheel output from the third and fourth wheel speed sensors and this This is an acceleration slip prevention device for a vehicle, which is equipped with a braking means that brakes the driving wheels according to the difference from the reference wheel speed and also strengthens the braking force on the inner wheel side when turning.

(Embodiment) Hereinafter, an acceleration slip prevention device for a vehicle according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an acceleration slip prevention device for a vehicle. The figure shows a front-wheel drive vehicle, and WPR is the front right wheel,
WFL is the front left wheel, WRR is the rear right wheel, WRL
indicates the rear left wheel. Further, 11 is a wheel speed sensor that detects the wheel speed VFR of the front right wheel (drive wheel) WPR, 12 is a wheel speed sensor that detects the wheel speed VPL of the front left wheel (drive wheel) WFL, and 13 is the rear right wheel. (Driver wheel) WRR wheel speed Vl? A wheel speed sensor 14 detects the wheel speed VRL of the rear left wheel (driven wheel) WRL. Wheel speed VFR detected by the wheel speed sensors 11 to 14
, VI'L, VRI? , V! ? L is) La') '
/-s is input to the controller 15. The traction controller 15 sends a control signal to the engine 16 to perform control to prevent the drive wheels from slipping during acceleration. This engine 16 has a main throttle valve TH11 whose opening degree is controlled by an accelerator pedal, and a sub-throttle valve THs whose opening degree is controlled by a control signal f9s from the traction controller 15. The opening degree of the auxiliary throttle valve THs is controlled by the control signal from the traction controller 15.
The driving force of the engine 16 is controlled.

Further, 17 is a wheel cylinder that brakes the front right wheel WFR, and 18 is a wheel cylinder that brakes the front left wheel WPL. Normally, pressurized oil is supplied to these wheel cylinders via master back and mask cylinders (not shown) by operating a brake pedal (not shown). When traction control is activated, pressure oil can be supplied from another route as described below.

Pressure oil is supplied from the hydraulic source 19 to the wheel cylinder 17 through an inlet valve 17i, and pressure oil is discharged from the wheel cylinder 17 to the reservoir 20 through an outlet valve 17o. Further, pressure oil is supplied from the hydraulic source 19 to the wheel cylinder 18 through an inlet valve 18i, and pressure oil is discharged from the wheel cylinder 18 to the reservoir 20 through an outlet valve 18o. Opening/closing control of the inlet valves 17i and 181 and the out 1-knot valves 170 and 180 is performed by the traction controller 15.

Next, the detailed configuration of the traction controller 15 will be described with reference to FIG. 2. Wheel speed sensor 1
Wheel speed VFR of the driving wheels detected at 1 and 12
and VFL are sent to a high vehicle speed selection section (SH) 31, and the higher wheel speed is selected between wheel speed VFR and wheel speed VPL and output. At the same time, vehicle speed sensor 1
Wheel speed VFR of the driving wheels detected at 1 and 12
and VFL are averaged in the averaging section 32 to calculate the average wheel speed (V Pl?+V PI-,)/2. The wheel speed output from the high vehicle speed selection section 31 is multiplied by a variable KG in the weighting section 33, and
The average wheel speed outputted from the weighting unit 34 is multiplied by a variable (1-KG), and each of the weighted wheels is sent to an adding unit 35 and summed to obtain the driving wheel speed vF. In addition, the variable K
G is a variable that changes depending on the centripetal acceleration GY, as shown in FIG. As shown in FIG. 3, it is set so that the centripetal acceleration GY is proportional to the centripetal acceleration until it reaches a predetermined value (for example, 0.1 g), and becomes "1" when it exceeds that value.

Further, the wheel speeds of the driven wheels detected by the wheel speed sensors 13 and 14 are input to a low vehicle speed selection section 36, and the smaller wheel speed is selected. Furthermore, the wheel speeds of the driven wheels detected by the wheel speed sensors 13 and 14 are input to a high vehicle speed selection section 37, and the larger wheel speed is selected. The smaller wheel speed selected by the low vehicle speed selection section 36 is multiplied by a variable Kl in a weighting section 38, and the larger wheel speed selected by the high vehicle speed selection section 37 is weighted by a factor K1. 39, the variable is multiplied by (1-Kr). This variable Kr is the centripetal acceleration GY as shown in Figure 4.
It changes between "1" and "0" depending on the time.

Further, the wheel speeds outputted from the weighting section 38 and the weighting section 39 are added in an adding section 40 to obtain the driven wheel speed VR, and further, the driven wheel speed VR is determined in a multiplication section 40' (1+α ) multiplied by target drive wheel speed V
It is assumed to be Φ.

Then, the driving wheel speed vp output from the adding section 35
and the target drive wheel speed VΦ output from the multiplier 40'.
is subtracted by the subtraction unit 41 to obtain the slip amount DVi'
(-VP-VΦ) is calculated. This slip ff1
DVi' is further added to the centripetal acceleration G in the addition section 42.
Slip f according to the rate of change GY of Y and centripetal acceleration GY
Correction of f1DVi' is performed. In other words, the slip amount correction section 43 is set with a slip correction ffiVg that changes according to the centripetal acceleration GY as shown in FIG.
The slip amount correction unit 44 has a slip correction QV that changes according to the rate of change GY of the centripetal acceleration GY as shown in FIG.
d is set. Then, in the adding section 42, the slip correction amounts vd and Vg are added to the slip amount DVi' outputted from the subtracting section 41, and the slip QD
It is considered as Vi.

This slip RDVi is sent to a calculation unit 45a in the TSn calculation unit 45 at a sampling time T of, for example, I5n+s, and the slip QDVi is integrated while being multiplied by a coefficient KI to obtain a correction torque TSn. That is, the correction torque obtained by correcting the slip QDVi, that is, the integral type correction torque TSn is obtained by adding TSn-Σ to ■DVi (Kl is a coefficient that changes according to the slip QDVt).

Further, the slip QDVi is sent to the calculating section 46a of the TPn7frL calculating section 46 every sampling time T, and the corrected torque TPn corrected by the slip QDVi is calculated. That is, the correction torque corrected by the slip QDVi, that is, the proportional correction torque TPn is obtained as TPn -DV 1 -Kp (Kp is a coefficient).

Further, the driven wheel speed VR output from the addition section 40 is inputted to the reference torque calculation section 47 as the vehicle body speed VB. This reference torque calculating section 47 calculates a reference torque TG that can be transmitted without causing slip on a road surface having a friction coefficient μ based on the driven wheel speed VR.

The reference torque TG and the integral correction torque T
Subtraction with Sn is performed in a subtraction unit 48, and further subtraction with the proportional correction torque TPn is further performed in a subtraction unit 49. In this way, the target torque TΦ
is calculated as TΦ-TG-TSn-TPn.

Then, this target torque TΦ is converted in the torque/throttle opening converter 50 into an engine torque for generating the target torque TΦ and a throttle valve opening for generating this engine torque. Ru. Then, by adjusting the opening degree es of the sub-throttle valve, the output torque of the engine is controlled so as to reach the target engine torque TΦ.

Also, the wheel speed VI of the driven wheel? R and VRL are sent to the centripetal acceleration calculating section 53, and the centripetal acceleration GY' is obtained in order to determine the degree of turning. This centripetal acceleration GY' is sent to the centripetal acceleration correction section 54, and the centripetal acceleration GY' is corrected according to the vehicle speed.

In other words, GY-Kv ・GY', and the coefficient ν changes according to the vehicle speed as shown in FIGS. 7 to 12, so that the centripetal acceleration GY is corrected according to the vehicle speed. .

Incidentally, the wheel speed of the driven wheel having the higher vehicle speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFR of the driving wheel in the subtraction section 55.

Furthermore, the wheel speed of the driven wheel which is greater than the vehicle speed of the driven wheel outputted from the high vehicle speed selection section 37 is subtracted from the wheel speed VPL of the driving wheel in the subtraction section 56.

The output of the subtraction unit 55 is multiplied by KB (0
<KB<1), and the output of the subtraction section 56 is outputted to the multiplication section 58.
After being multiplied by (1-KB) in the adding section 59, the slip ff1DVPR of the right drive wheel is obtained. At the same time, the output of the subtraction section 56 is multiplied by KB in the multiplication section 60, and the output of the subtraction section 55 is multiplied by KB in the multiplication section 60.
is multiplied by (1-KB) and then added in the adder 62 to obtain the slip mDVFL of the left drive wheel. As shown in Fig. 13, the variable KB changes according to the elapsed time from the start of traction control, and when the traction control starts, r
It is set to rO, 5J, and as the traction control progresses, it approaches rO, 8J. For example, when KB is rO, 8J, when slip occurs in only one drive wheel, the brake control is performed by recognizing that slip has occurred in the other drive wheel by 20% of that of the other drive wheel. ing. This is because if the brakes on the left and right drive wheels are made completely independent, only one drive wheel will be braked, and when the rotation decreases, the opposite drive wheel will slip due to the action of the differential and the brakes will be applied. This is because it is repeated and is not desirable. The slip fi DV PR of the right drive wheel is differentiated in a differentiator 63 to calculate the amount of change over time, that is, the slip acceleration GFR, and the slip amount DVl'L of the left drive wheel is differentiated in a differentiator 64. The amount of change over time, that is, the slip acceleration GFL is calculated. Then, the slip acceleration GPR is sent to the brake fluid pressure change amount (ΔP) calculation unit 65, and the fourteenth
The amount of change ΔP in brake fluid pressure for suppressing slip acceleration GFR is determined by referring to the GFR(GPL)-ΔP conversion map shown in the figure. Similarly, the slip acceleration GFL is determined by the brake fluid pressure change (ΔP) calculation unit 6.
GFR (GFL)- as shown in FIG.
The ΔP conversion map is referred to to determine the amount of change ΔP in brake fluid pressure for suppressing slip acceleration GPL.

In addition, in Fig. 14, when applying the brakes when turning, in order to strengthen the brakes on the inner drive wheels,
The inner wheel side when turning is shown by a broken line a.

Next, the operation of the acceleration slip prevention device for a vehicle according to an embodiment of the present invention, which has been completed in (1) above, will be explained. In FIGS. 1 and 2, the wheel speed sensor 13
．． The wheel speed of the driven wheel (rear wheel) output from the high vehicle speed selection section 36. Low vehicle speed selection section 37. Centripetal acceleration calculation unit 5
3 is input.

In the low vehicle speed selection section 36, the smaller wheel speed of the left and right driven wheels is selected, and the high vehicle speed selection section 37
In , the wheel speed of the larger one of the left and right driven wheels is selected. When the wheel speeds of the left and right driven wheels are the same during normal straight-line driving, the low vehicle speed selection section 3
The same wheel speed is selected from 6 and the high vehicle speed selection section 37. In addition, the wheel speeds of the left and right driven wheels are input to the centripetal acceleration calculation unit 53, and the turning angle when the vehicle is turning, that is, how steep the turn is, is determined from the wheel speeds of the left and right driven wheels. The degree to which the

Hereinafter, a description will be given of how the centripetal acceleration is calculated in the centripetal acceleration calculating section 53.

In a front wheel drive vehicle, the rear wheels are driven wheels, so the vehicle speed at that position can be detected by the JLIL chain wheel sensor regardless of slip caused by the drive, so Ackermann geometry can be used. In other words, in a steady turn, the centripetal acceleration GY' is GY'-v2/r
-(1) (■-vehicle speed, r-turning radius).

For example, when the vehicle is turning to the right as shown in FIG. 16, the turning center is Mo, and the turning center M
If the distance from o to the inner wheel (WRR) is r[, the tread is Δr, the l speed of the inner wheel (WRL) is ■1, and the wheel speed of the outer wheel is ■2, then v2/ vl=(Δr+rl)/rl・(2)
It is said that

Then, by modifying the above equation (1), 1/rl −(v2 −vl )/Δ r−vl−
(3). Then, the claimed center acceleration GY' characterized by the inner ring side is GY=v12/rl-vl2(v2-vl)/Δr-vl-vl
It is calculated as (V2-Vl)/Δr·(4).

That is, the centripetal acceleration GY' is calculated using the fourth equation.

By the way, when turning, the inner wheel speed v1 is smaller than the outer wheel speed v2, so the inner wheel speed v1 is used to calculate the centripetal acceleration GY', so the centripetal acceleration GY' is calculated to be smaller than the actual one. be done. Therefore, the coefficient KG multiplied by the weighting section 33 is estimated to be small because the centripetal acceleration GY' is estimated to be small. Therefore, since the driving wheel speed VF is estimated to be small, the slip *D V '(V F -VΦ) is also estimated to be small. As a result, the estimated target torque TΦ is greatly deviated from the estimated value, so that the target engine torque is estimated to be large, thereby providing sufficient driving force even when turning.

By the way, in the case of extremely low speed, the distance from the inner wheel side to the turning center MO is rl, as shown in Fig. 16, but in a vehicle that understeers as the speed increases, the turning center is at M. The distance is r(r>r
l).

Even when the speed increases in this way, since the turning radius is calculated as rl, the centripetal acceleration GY' calculated based on the first equation above is calculated as a larger value than the actual value. Therefore, the centripetal acceleration GY' calculated in the centripetal acceleration calculation section 53 is sent to the centripetal acceleration correction section 54, so that the centripetal acceleration GY becomes smaller at high speeds.
The centripetal acceleration GY' is multiplied by the coefficient Kv shown in FIG. This variable Kv is set to decrease as the vehicle travels eastward, and may be set as shown in FIG. 8 or 9. In this way, the centripetal acceleration correction unit 54 outputs the corrected centripetal acceleration GY.

On the other hand, as the speed increases, oversteer occurs (r<
(rl) In the vehicle, the centripetal acceleration correction unit 54 performs a correction that is completely opposite to that of the above-mentioned understeered vehicle. In other words, as the vehicle speed increases, the centripetal acceleration GY' calculated by the centripetal acceleration calculating section 53 is
is corrected so that it becomes larger.

By the way, the smaller wheel speed selected in the low vehicle speed selection section 36 is multiplied by the variable Kr in the weight section 38 as shown in FIG. 4, and the high vehicle speed selected in the high vehicle speed selection section 37 is not weighted. In part 39, the variable (1-Kr
) will be multiplied. The variable Kr is the centripetal acceleration GY of 0.9, for example.
When the centripetal acceleration GY becomes larger than 0.4 g, it becomes "1", and when the centripetal acceleration GY becomes smaller than 0.4 g, it becomes "0".
” is set.

Therefore, for a turn in which the centripetal acceleration GY is greater than 0.9 g, the wheel speed of the lower vehicle speed among the driven wheels output from the low vehicle speed selection section 36, that is, the wheel speed of the inner wheel at the time of selection is selected. be done.

Then, the weighting is performed by adding the wheel speeds output from sections 38 and 39 in an adding section 40 to obtain the driven wheel speed VR.
In addition, the driven wheel speed Vl? is multiplied by (1+α) in the multiplier 40' to obtain the target driving wheel speed VΦ.

Further, after the higher wheel speed of the drive wheels is selected in the high vehicle speed selection section 31, weighting is performed in the section 33.
In this case, the variable KG is multiplied as shown in FIG. Furthermore, the average vehicle speed (V
FR+VFL)/2 is weighted in section 34,
(1-KG), and the above-mentioned weighting is added to the output of the section 33 and the adding section 35 to obtain the driving wheel speed VP. Therefore, when the centripetal acceleration GY becomes, for example, 0.1 g or more,
KG-1, the wheel speed of the larger of the two drive wheels output from the high vehicle speed selection section 31 is output. In other words, when the turning angle of the vehicle increases and the centripetal acceleration GY becomes, for example, 0.9 g or more,
rKG-Kr-1'', on the driving wheel side, the wheel speed of the outer wheel with a higher wheel speed is set as the driving wheel speed VF, and on the driven wheel side, the wheel speed of the inner wheel with a lower wheel speed is set as the driven wheel speed VR. Therefore, since the slip amount DVi' (-VP-VΦ) is calculated by the subtraction unit 41,
The slip ff1DVi' is overestimated. Therefore, in order to estimate the target torque TΦ to be small, the engine output is reduced and the slip ratio S is reduced to reduce the first
As shown in FIG. 5, the lateral force A can be increased, the grip force of the tire during turning can be increased, and safe turning can be achieved.

To the slip iDV', a slip correction mVg as shown in FIG. 5 is added in the slip amount correction section 43 only when turning when centripetal acceleration GY occurs, and a slip correction mVg as shown in FIG. Slip Q
Vd is added. For example, when assuming a right-angled curve turn, in the first half of the turn, the centripetal acceleration G
Y and its temporal change rate GY take a positive value, but in the latter half of the curve, the temporal change rate Gt of the centripetal acceleration GY takes a negative value. Therefore, in the first half of the curve, the adder 42 applies the slip correction JmVg (>0) and the slip correction shown in FIG. 5 to the slip m D V i '.
QVd (>0) is added to the slip mDVi,
In the latter half of the curve, slip compensation +F, mVg (>0
) and slip correction RV d(kuO) are added to obtain slip 1iDVi.

Therefore, the slip fa D V i in the latter half of the turn
By estimating the slip m D V i to be smaller than the slip m D V i in the first half of the turn, the engine output is reduced in the first half of the turn to increase the lateral force, and in the second half of the turn, the engine output is recovered compared to the first half and the vehicle We are trying to improve the acceleration of.

In this way, the corrected slip JmDVi is sent to the TSn calculation unit 45 with a sampling time T of, for example, 15 m5. In this TSn calculating section 45, the slip QDvi becomes a coefficient! The corrected torque TSn is obtained by multiplying and integrating.

That is, the correction torque obtained by correcting the slip m D Vi, that is, the integral type correction torque TSn is obtained as TSn - ΣK I - Dvi (Kl is a coefficient that changes depending on the slip ill D Vi).

In addition, the above-mentioned slip r:LD V I is sent to the TPn calculation unit 46 every 1T at the time of sampling, and the correction torque T
Pn is calculated. That is, the correction torque corrected by the slip m DV +, that is, the proportional correction torque TPn is obtained as TPn - DVI xKp (Kp is a coefficient).

Further, the driven wheel speed VR outputted from the addition section 40 is manually input to the reference torque calculation section 47 as the vehicle body speed VB. Then, the reference torque calculation unit 47 calculates a reference torque TG that can be transmitted to a road surface with a friction coefficient μ without pickpockets or knobs.

The reference torque TG and the integral correction torque T
Subtraction with Sn is performed in a subtraction section 48, and further, the proportional correction torque TPn is further performed in a subtraction section 49. In this way, the target torque TΦ is calculated as TΦ - T G - T S n - T P n.

This target torque TΦ is then sent to the torque/throttle opening converter 50 and converted into a throttle opening es for generating the target torque TΦ.

Incidentally, the wheel speed of the driven wheel having the higher vehicle speed output from the high vehicle speed selection section 37 is subtracted from the wheel speed VFR of the driving wheel in the subtraction section 55.

Further, the wheel speed vrt of the driving wheel and the wheel speed of the driven wheel having the higher vehicle speed output from the high vehicle speed selection section 37 are subtracted in the subtraction section 56. Therefore, the subtractor 5
By estimating the outputs of 5 and 56 to be small, the number of times the brake is used even during a turn is reduced, and the slip of the drive wheels is reduced by reducing the engine torque.

The output of the subtractor 55 is multiplied by K8 (
0<I (B<1), and the output of the subtraction section 56 is multiplied by (1-KB) in the multiplication section 58, and then added in the addition section 59 to obtain the slip ff1DVFR of the right drive wheel. At the same time, the output of the subtraction section 56 is
The output of the subtraction section 55 is multiplied by (1-KB) in a multiplication section 61 and then added in an addition section 62 to obtain the slip QDVFL of the left driving wheel. As shown in Fig. 13, the variable KB changes according to the elapsed time from the start of traction control, and is set to ro and 5 J at the start of traction control, and as the traction control progresses, ro changes. , 8 J. In other words, when reducing drive wheel slip by braking, it is recommended to apply brakes simultaneously across both vehicle widths at the beginning of braking to reduce unpleasant steering shock when braking starts on a split road, for example. can. Brake control is continued and K
The operation when B becomes rO, 8J will be explained. In this case, when slip occurs in only one drive wheel, the brake control is performed by recognizing that slip has occurred in the other drive wheel by 20% of that of the one drive wheel. This is because if the brakes on the left and right drive wheels are completely independent, when only one drive wheel is braked and its rotation is reduced, the action of the differential causes the opposite drive wheel to slip and apply the brakes. This is because it is repeated and is not desirable. Slip m of the right drive wheel above
D V PR is differentiated in a differentiator 63 to obtain the amount of change over time, that is, the slip acceleration GFI? is calculated, and the slip amount D V I'L of the left driving wheel is calculated.
is differentiated by the differentiator 64 to calculate the amount of change over time, that is, the slip acceleration GFL. And the slip acceleration GPI mentioned above? is the brake fluid pressure change ff1(Δ
P) GPI?? sent to the calculation unit 65 and shown in FIG. (
GFL)-ΔP conversion map is referred to and the slip acceleration Gl'l? Brake fluid pressure change port ΔP to suppress
is required. Similarly, slip acceleration Gl? L
is sent to the brake fluid pressure change amount (ΔP) calculation unit 66,
With reference to the GPR(GFL)-ΔP conversion map shown in FIG. 14, the amount of change ΔP in brake fluid pressure for suppressing slip acceleration GFL is determined.

In addition, in Fig. 14, when applying the brakes when turning, in order to strengthen the brakes on the inner drive wheels,
The inner wheel side when turning is shown by a broken line a. In this way, when turning, the load shifts to the outer wheel side and the inner wheel side becomes prone to slipping. This can sometimes prevent the inner ring from slipping.

In addition, although the calculation of the centripetal acceleration GY' in the centripetal acceleration calculation unit 53 in the above embodiment was based on the inner wheel speed ■1, the invention is not limited to this, and the inner wheel speed ■1 and the outer wheel speed may be used as a reference. It may be calculated based on the average with v2, or based on the outer wheel speed v2.

For example, a case will be described in which the centripetal acceleration GY' is calculated based on the average of the inner wheel speed vl and the outer wheel speed v2. In this case, the centripetal acceleration GY' is obtained by substituting v-v2+vl/2 r-(rl+Δr)/2 into the first equation and transforming it using equation (2), GY' =
(v22-vl 2)/2 Δr-<5).

On the other hand, when the outer wheel speed ■2 is used as the reference, the above first equation is expressed as vxv2. Substituting r-rl+Δr (2
) is transformed using the formula: GY' = (v2-vl,)v2/Δr-C
6).

Therefore, when the centripetal acceleration GY' is calculated using the outer wheel speed v2 as a reference, the centripetal acceleration GY' is estimated to be larger than the actual value, so the slip Q D V'
is estimated to be larger than the actual value, so the L1 mark torque TΦ is estimated to be smaller than the actual value, and the engine output torque is made smaller than the actual value, thereby increasing the lateral force and improving the turning performance. In addition, the centripetal acceleration GY' is calculated based on the average of the inner wheel speed v1 and the outer wheel speed v2.
When Y' is calculated, as described above, intermediate engine output control is performed between the case where the inner wheel speed v1 is used as the basis and the case where the outer wheel speed v2 is used as the standard. , specific emphasis can be placed on both the driving force and turning performance during turning.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an acceleration slip prevention device 11 for a vehicle that can suppress the occurrence of slips during turns and enable safe turns.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a vehicle acceleration slip prevention device according to an embodiment of the present invention, FIG. 2 is a block diagram showing control of the traction controller in FIG. 1 divided into functional blocks, and FIG. FIG. 3 is a diagram showing the relationship between centripetal acceleration GY and variable KG, FIG. 4 is a diagram showing the relationship between centripetal acceleration GY and variable Kr, and FIG. 5 is a diagram showing the relationship between centripetal acceleration GY and slip correction QVg, and FIGS. Fig. 12 shows the relationship between the vehicle speed VB and the variable Kv, Fig. 13 shows the change over time in the variable KB from the start of brake control, and Fig. 14 shows the change over time in the amount of slip m G PR (G i'L) and the amount of change ΔP in brake fluid pressure. Figure 15 is a diagram showing the relationship between slip ratio S, friction coefficient μ between tire and road surface, and lateral force (side force). The figure shows the turning radius rl, r, ) red Δr when the vehicle is turning to the right. 11 to 14... are wheel speed sensors, 15... traction controller, 45... TSn calculation unit, 46...
・TPn calculation section, 47... Reference torque calculation section, 50.
...Torque/throttle opening conversion section, 53... Centripetal acceleration calculation section, 54... Centripetal acceleration correction section. Patent attorney Takehiko Suzue, representative of the applicant 12 Figure 13 Figure 14 rXJ i i6 @ 15 Figure 1゜Indication of the casePatent application No. 14 No. 1983 2゜Name of the invention Vehicle acceleration slip prevention device 3゜Relationship with the case

Claims (1)

[Claims] By detecting the driving wheel speed and the driven wheel speed, calculating the amount of slip according to the difference between the driving wheel speed and the driven wheel speed, and controlling the output torque of the engine and braking the driving wheel according to this slip amount, the driving wheel speed is controlled. An acceleration slip prevention device for a vehicle configured to reduce slip includes a first wheel speed sensor that detects the wheel speed of one driven wheel of the vehicle, and a first wheel speed sensor that detects the wheel speed of the other driven wheel of the vehicle. a third wheel speed sensor that detects the wheel speed of one driving wheel of the vehicle; a fourth wheel speed sensor that detects the wheel speed of the other driving wheel of the vehicle;
The wheel speed VR of the one driven wheel detected by the wheel speed sensor of the second driven wheel and the wheel speed of the other driven wheel detected by the second wheel speed sensor is set as the reference wheel speed. a braking means for braking the driving wheels according to the difference between the wheel speed of the driving wheels outputted from the third and fourth wheel speed sensors and the reference wheel speed, and strengthening the braking force on the inner wheel side when turning. A vehicle acceleration slip prevention device characterized by comprising: