JPH0813633B2 - Vehicle acceleration slip prevention device - Google Patents

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 which improves the turning performance of the vehicle.

(Prior Art) Conventionally, there is known an acceleration slip prevention device (traction control device) that prevents slippage of drive wheels that occurs when an automobile is suddenly accelerated. In such a traction control device, when the acceleration slip of the driving wheels is detected, the slip ratio S is controlled so that the friction coefficient μ between the tire and the road surface falls within the maximum range (hatched range in FIG. 15). Here, the slip ratio S is [(VF-VB)
/ VF] × 100 (percent), VF is the wheel speed of the driving wheel, and VB is the vehicle speed. That is, when the slip of the driving wheel is detected, the wheel speed VF of the driving wheel is controlled by controlling the engine output so that the slip ratio S is in the shaded range, and the friction coefficient μ between the tire and the road surface is maximum. The range is controlled so that the drive wheels do not slip during acceleration and the acceleration performance of the vehicle is improved.

(Problems to be Solved by the Invention) By the way, as a factor for improving the turning performance of the automobile when turning, there is a lateral force (side force) generated in the tire. By increasing the lateral force, a large cornering force can be obtained, and the turning performance can be improved. This lateral force is determined by the slip ratio S as shown in FIG.
Is gradually reduced when becomes larger. Therefore, the friction coefficient μ
At the position where is the maximum range, the lateral force is insufficient, and there is a problem that the turning performance cannot be sufficiently exhibited.

The present invention has been made in view of the above points, and an object of the present invention is to accelerate a vehicle by controlling the lateral force to be large at the time of turning and suppressing the occurrence of slip at the time of turning to improve the turning performance. It is to provide an anti-slip device.

Configuration of the Invention (Means and Actions for Solving the Problem) A driven wheel speed sensor for detecting a wheel speed of a driven wheel of a vehicle, a driven wheel speed sensor for detecting a wheel speed of a drive wheel of the vehicle, Based on the wheel speed of the driven wheel detected by the driven wheel speed sensor and the wheel speed of the driving wheel detected by the driving wheel speed sensor, a slip state amount indicating the magnitude of the slip occurring on the driving wheel is calculated. Slip detection means for detecting, braking means for braking the drive wheels, braking the braking means according to the slip state amount detected by the slip detection means, and when the vehicle is in a turning state, An acceleration slip prevention device for a vehicle, comprising: braking means for correcting the braking force on the inner wheel side in an increasing direction from a magnitude corresponding to the slip state amount. That.

(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 block diagram showing an acceleration slip prevention device for a vehicle. The figure shows a front wheel drive vehicle, WFR is the front right wheel,
WFL indicates a front left wheel, WRR indicates a rear right wheel, and WRL indicates a rear left wheel. Further, 11 is a wheel speed sensor for detecting the wheel speed VFR of the front right wheel (driving wheel) WFR, 12
Is a wheel speed sensor for detecting the wheel speed VFL of the front left wheel (driving wheel) WFL, 13 is a wheel speed sensor for detecting the wheel speed VRR of the rear right wheel (driven wheel) WRR, and 14 is a rear left wheel (secondary wheel). Driving wheel) A wheel speed sensor for detecting the wheel speed VRL of WRL. The wheel speeds VFR, VFL, VRR, VRL detected by the wheel speed sensors 11 to 14 are traction controllers.
Entered in 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 whose opening is controlled by an accelerator pedal.
In addition to THm, an auxiliary throttle valve whose opening is controlled by a control signal Θs from the traction controller 15
The driving force of the engine 16 is controlled by controlling the opening degree of the auxiliary throttle valve THs by a control signal from the traction controller 15.

Reference numeral 17 denotes a wheel cylinder for braking the front right wheel WFR, and reference numeral 18 denotes a wheel cylinder for braking the front left wheel WFL. Normally, pressure oil is supplied to these wheel cylinders via a master back and a master cylinder (not shown) by operating a brake pedal (not shown). At the time of traction control operation, pressure oil can be supplied from another path described below. The pressure oil is supplied to the wheel cylinder 17 from the hydraulic pressure source 19 through the inlet valve 17i, and the pressure oil is discharged from the wheel cylinder 17 to the reservoir 20 through the outlet valve 17o. Also, the above wheel cylinder 1
The supply of pressure oil from the oil pressure source 19 to the
Through the wheel cylinder 18 from the reservoir
The pressure oil is discharged to 20 through an outlet valve 18o. The traction controller 15 controls the opening and closing of the inlet valves 17i and 18i and the outlet valves 17o and 18o.

Next, the detailed configuration of the traction controller 15 will be described with reference to FIG. Wheel speed sensor 11
The wheel speeds VFR and VFR of the drive wheels detected in
The FL is sent to a high vehicle speed selecting section (SH) 31, and a higher wheel speed is selected and output from the wheel speed VFR and the wheel speed VFL. At the same time, the wheel speeds VFR and FFL of the drive wheels detected by the vehicle speed sensors 11 and 12 are averaged by the averaging unit 32 to calculate the average wheel speed (VFR + VFL) / 2. The wheel speed output from the high vehicle speed selection unit 31 is multiplied by the variable KGB in the weighting unit 33, and the average wheel speed output from the averaging unit 32 is multiplied by the variable (1-KG) in the weighting unit 34 and added. It is sent to the section 35 and accelerated to the driving wheel speed VF. Note that the variable KG is the third
As shown in the figure, it is a variable that changes according to the centripetal acceleration GY. As shown in FIG. 3, the centripetal acceleration GY is set so as to be proportional to the centripetal acceleration up to a predetermined value (for example, 0.1 g, where g is the gravitational acceleration), and to become "1" when it exceeds that. .

The wheel speeds of the driven wheels detected by the wheel speed sensors 13 and 14 are input to the low vehicle speed selection unit 36, and the smaller wheel speed is selected. Further, the wheel speed sensor 1
The wheel speeds of the driven wheels detected in 3 and 14 are input to the high vehicle speed selection unit 37, and the larger wheel speed is selected. Then, the smaller wheel speed selected by the low vehicle speed selector 36 is multiplied by the variable Kr in the weighting unit 38, and the larger wheel speed selected by the high vehicle speed selector 37 is weighted by the weighting unit 39.
Is multiplied by the variable (1-Kr) at. This variable Kr changes between "1" and "0" according to the centripetal acceleration GY as shown in FIG.

Further, the wheel speeds output from the weighting unit 38 and the weighting unit 39 are added in an adding unit 40 to be a driven wheel speed VR, and the driven wheel speed VR is further multiplied by a multiplication unit 40 '.
Is multiplied by (1 + α) to obtain the target drive wheel speed VΦ.

The drive wheel speed VF output from the adder 35
And the target drive wheel speed VΦ output from the multiplication unit 40 'is subtracted by the subtraction unit 41 to obtain the slip amount DVi' (= VF-
VΦ) is calculated. The slip amount DVi 'is further corrected in the adder 42 in accordance with the centripetal acceleration GY and the change rate G of the centripetal acceleration GY. That is, the slip correction amount Vg that changes according to the centripetal acceleration GY as shown in FIG. 5 is set in the slip amount correction unit 43, and the centripetal acceleration as shown in FIG. 6 is set in the slip amount correction unit 44. A slip correction amount Vd that changes according to the change rate G of GY is set. Then, the addition unit 42 adds the slip correction amounts Vd and Vg to the slip amount DVi 'output from the subtraction unit 41 to obtain the slip amount DVi.

The slip amount DVi is sent to the calculation unit 45a in the TSn calculation unit 45 at a sampling time T of, for example, 15 ms, and
DVi is multiplied by a coefficient KI and integrated to obtain a correction torque TSn.
Is required. That is, the correction torque obtained by integrating the slip amount DVi, that is, the integral correction torque TSn is obtained as TSn = ΣKI · DVi (KI is a coefficient that changes in accordance with the slip amount DVi).

The slip amount DVi is T at every sampling time T.
The correction torque TPn, which is sent to the calculation unit 46a of the Pn calculation unit 46 and is proportional to the slip amount DVi, is calculated. That is, a correction torque proportional to the slip amount DVi, that is, a proportional correction torque TPn is obtained as TPn = DVi · Kp (Kp is a coefficient).

The driven wheel speed VR output from the adder 40 is input to the reference torque calculator 47 as the vehicle body speed VB.
The reference torque calculator 47 calculates a reference torque TG that can be transmitted without causing a slip on a road surface having a friction coefficient μ based on the driven wheel speed VR.

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

Then, the target torque TΦ is calculated by a torque / throttle opening degree converter 50 to calculate an engine torque for generating the target torque TΦ and to convert the target torque TΦ to a sub-throttle valve opening degree for generating the engine torque. You. Then, by controlling the opening degree Δs of the sub throttle valve, the output torque of the engine is controlled so as to become the target engine torque TΦ.

The wheel speeds VRR and VRL of the driven wheels are calculated by a centripetal acceleration calculation unit.
Sent to 53, centripetal acceleration G to judge turning degree
Y 'is required. The centripetal acceleration GY ′ is sent to the centripetal acceleration correction unit 54, and the centripetal acceleration GY ′ is corrected according to the vehicle speed.

That is, GY = Kv · GY ′, and the coefficient Kv changes according to the vehicle speed as shown in FIGS. 7 to 12, whereby the centripetal acceleration GY is corrected according to the vehicle speed.

Incidentally, the wheel speed of the driven wheel output from the high vehicle speed selecting unit 37 having a larger value is subtracted from the wheel speed VFR of the driving wheel by the subtracting unit 55.
Is subtracted. Further, the subtracting unit 56 subtracts the wheel speed of the driven wheel having the larger value from the output of the high vehicle speed selecting unit 37 from the wheel speed VFL of the driving wheel.

The output of the subtractor 55 is multiplied by KB in the multiplier 57 (0 <
KB <1), the output of the subtraction unit 56 is multiplied by (1-KB) in the multiplication unit 58, and then added in the addition unit 59 to obtain the slip amount DVFR of the right driving wheel. At the same time,
The output of the subtraction unit 56 is multiplied by KB in the multiplication unit 60, the output of the subtraction unit 55 is multiplied by (1-KB) in the multiplication unit 61, and then added in the addition unit 62 to obtain the slip amount DVFL of the left driving wheel. It is said that As shown in FIG. 13, the variable KB changes according to the elapsed time from the start of the control of the traction control, and is set to "0.5" at the start of the control of the traction control, and becomes "0.8" as the control of the traction control progresses. Is set to approach. For example, when KB is set to "0.8", when one of the driving wheels slips, the other driving wheel recognizes that a slip of only 20% of one driving wheel has occurred, and performs the brake control. ing. This is because if the brakes on the left and right drive wheels are made completely independent, when only one drive wheel is braked and the rotation is reduced, the drive wheel on the opposite side will slip and the brake will be applied due to the action of the differential. This is because the operation is repeated, which is not preferable. The slip amount DVFR of the above right drive wheel is the differential part
At 63, the temporal change amount, that is, the slip acceleration GFR is calculated, and at the same time, the slip amount DVFL of the left driving wheel is differentiated at the differentiating section 64, and the temporal change amount, that is, the slip addition degree GFL is calculated. To be done. The slip acceleration GFR is calculated based on the amount of change in brake fluid pressure (Δ
P) It is sent to the calculation unit 65 and GFR (GFL) -shown in FIG.
The change amount ΔP of the brake fluid pressure for suppressing the slip acceleration GFR is obtained by referring to the ΔP conversion map. Similarly, the slip acceleration GFL is sent to the brake fluid pressure change amount (ΔP) calculation unit 66, and GFR (GF) shown in FIG.
L) -ΔP conversion map is referred to, slip acceleration GF
A change amount ΔP of the brake fluid pressure for suppressing L is obtained.

Incidentally, in FIG. 14, when the brake is applied at the time of turning, in order to strengthen the brake of the inner drive wheel,
The inner wheel side when turning is shown by a broken line a.

Next, the operation of the vehicle acceleration slip prevention device according to the embodiment of the present invention configured as described above will be described. In FIGS. 1 and 2, the wheel speed sensors 13 and 14 are shown.
The wheel speeds of the driven wheels (rear wheels) output from are input to the high vehicle speed selection unit 36, the low vehicle speed selection unit 37, and the centripetal acceleration calculation unit 53. In the low vehicle speed selection unit 36, the smaller wheel speed is selected from the left and right driven wheels, and the high vehicle speed selection unit 37 is selected.
In, the larger wheel speed of the left and right driven wheels is selected. During normal straight running, if the wheel speeds of the left and right driven wheels are the same, the low vehicle speed selection unit 36
The same wheel speed is selected from the high vehicle speed selection unit 37.
Further, in the centripetal acceleration calculation unit 53, the wheel speeds of the left and right driven wheels are input, and the turning degree when the vehicle is turning from the wheel speeds of the left and right driven wheels, that is, how sharp a turn is made. The degree of whether or not it is calculated is calculated.

Hereinafter, how the centripetal acceleration calculation unit 53 calculates the centripetal acceleration will be described. Since the rear wheels of the front-wheel drive vehicle are the driven wheels, the vehicle speed at that position can be detected by the wheel speed sensor regardless of the slip caused by driving, and therefore Ackermann geometry can be used. That is, centripetal acceleration GY is in the steady turning ^{'is, GY' = v 2 / r} ... (1) (v = vehicle speed, r = radius of turn) is calculated as.

For example, when the vehicle is turning right as shown in FIG. 16, the center of the turn is Mo, the distance from the center of the turn Mo to the inner wheel side (WRR) is r1, the tread is Δr, and the inner wheel is When the wheel speed on the side (WRL) is v1 and the wheel speed on the outer wheel is v2, v2 / v1 = (Δr + r1) / r1 (2)

Then, the above equation (1) is modified to be 1 / r1 = (v2-v1) / Δr · v1 (3). Then, the centripetal acceleration GY ′ based on the inner ring side
Is calculated as GY ′ = v1 ² / r1 = v1 ² · (v2-v1) / Δr · v1 = v1 · (v2-v1) / Δr (4).

That is, the centripetal acceleration GY 'is calculated by the equation (4). By the way, since the wheel speed v1 on the inner wheel side is smaller than the wheel intensity v2 on the outer wheel side during turning, the centripetal acceleration GY ′ is calculated using the wheel speed v1 on the inner wheel side.
Y'is calculated smaller than the actual value. Therefore, the weighting unit 3
The coefficient KG multiplied by 3 has a smaller value as the centripetal acceleration GY 'is estimated to be smaller. Therefore, the driving wheel speed VF
Is estimated to be small, the slip amount DV '-(VF
-VΦ) is also underestimated. As a result, the target torque TΦ is largely estimated, and the target engine torque is largely estimated, so that a sufficient driving force is applied even during turning.

By the way, in the case of extremely low speed, as shown in FIG. 16, the distance from the inner wheel side to the turning center Mo is r1,
In vehicles that understeer as speed increases, the center of turning moves to M and the distance is r (r> r1)
Has become. Even when the speed is increased in this way, since the turning radius is calculated as r1, the centripetal acceleration GY ′ calculated based on the above equation (1) is calculated as a value larger than the actual value. Therefore, the centripetal acceleration GY ′ calculated by the centripetal acceleration calculation unit 53 is equal to the centripetal acceleration correction unit 54.
The centripetal acceleration GY 'is multiplied by the coefficient Kv in FIG. 7 so that the centripetal acceleration GY becomes small at high speed. This variable Kv is set to be small according to the vehicle speed, and may be set as shown in FIG. 8 or FIG. In this way, the centripetal acceleration GY corrected by the centripetal acceleration correction unit 54 is output.

On the other hand, as the speed increases, oversteering (r
<R1) In the vehicle, the centripetal acceleration correction unit 54 performs a correction that is the reverse of the above-described understeering vehicle. That is, the variable Kv in any of FIGS. 10 to 12
Is used to correct the centripetal acceleration GY ′ calculated by the centripetal acceleration calculating section 53 to increase as the vehicle speed increases.

By the way, the smaller wheel speed selected by the low vehicle speed selection unit 36 is multiplied by a variable Kr in the weighting unit 38 as shown in FIG. 4, and the high wheel side selected by the high vehicle speed selection unit 37 is weighted by the weighting unit 39. Is multiplied by the variable (1-Kr) at. The variable kr is set to "1" during turning when the centripetal acceleration GY becomes larger than 0.9 g, for example.
When GY is smaller than 0.4g, it is set to "0".

Therefore, for turning such that the centripetal acceleration GY is larger than 0.9 g, the wheel speed of the low vehicle speed among the driven wheels output from the low vehicle speed selection unit 36, that is, the wheel speed on the inner wheel side during steering is selected. It And the weightings 38 and 39 above
The wheel speed output from the above is added in the adding section 40 to be the driven wheel speed VR, and the driven wheel speed VR is further multiplied by the multiplying section.
At 40 ', the target drive wheel speed VΦ is multiplied by (1 + α).

In addition, after the wheel speed of the larger one of the wheel speeds of the drive wheels is selected by the high vehicle speed selection section 31, the weighting section 33 multiplies the variable KG by a variable KG as shown in FIG. further,
Average vehicle speed of drive wheels calculated by averaging unit 32 (VFR +
VFL) / 2 is multiplied by (1-KG) in the weighting unit 34, and added by the output of the weighting unit 33 and the adding unit 35 to obtain the driving wheel speed VF. Therefore, when the centripetal acceleration GY is, for example, 0.1 g or more, KG = 1, so that the wheel speed of the larger drive wheel of the two drive wheels output from the high vehicle speed selection unit 31 is output. Become. That is,
The centripetal acceleration GY is, for example, 0.
When the weight is 9 g or more, "KG = Kr = 1", so that the driving wheel side uses the wheel speed of the outer wheel having a higher wheel speed as the driving wheel speed VF, and the driven wheel side uses the wheel speed of the inner wheel having a lower wheel speed. Is the driven wheel speed VR, and the slip amount DVi ′ (= VF−VΦ) calculated by the subtraction unit 41, the slip amount DVi ′ is largely estimated. Therefore, since the target torque TΦ is underestimated, the output of the engine is reduced, the slip ratio S can be reduced, and the lateral force A can be increased as shown in FIG. You can increase the force and make a safe turn.

The slip amount DVi 'is added to the slip amount correcting unit 43 with the slip correction amount Vg as shown in FIG. 5 only at the time of turning when the centripetal acceleration GY is generated, and the slip amount correcting unit 44 shows it in FIG. Such slip amount Vd is added. For example, assuming a turn at a right angle curve, the centripetal acceleration GY and its temporal change rate G are positive values in the first half of the turn, but the temporal change rate of the centripetal acceleration GY is in the latter half of the curve. G is a negative value. Therefore, in the first half of the curve, the slip correction amount Vg shown in FIG.
(> 0) and the slip correction amount Vd (> 0) are added to obtain the slip amount DVi, and in the latter half of the curve, the slip correction amount Vg (> 0) and the slip correction amount Vd (<0) are added. The slip amount is DVi. Therefore, the slip amount DVi in the latter half of the turn is estimated to be smaller than the slip amount DVi in the first half of the turn. In, the engine output is recovered from the first half to improve the acceleration of the vehicle after the end of the turn.

In this way, the corrected slip amount DVi is, for example, 1
It is sent to the TSn calculation unit 45 at a sampling time T of 5 ms. In the TSn calculator 45, the slip amount DVi is multiplied by the coefficient KI and integrated to obtain the correction torque TSn.
That is, the correction torque obtained by integrating the slip amount DVi, that is, the integral correction torque TSn is obtained as TSn = ΣKI · DVi (KI is a coefficient that changes in accordance with the slip amount DVi).

The slip amount DVi is T at every sampling time T.
The correction torque TPn is sent to the Pn calculation unit 46 and is calculated.
That is, a correction torque proportional to the slip amount DVi, that is, a proportional correction torque TPn is obtained as TPn = DVi · Kp (Kp is a coefficient).

The driven wheel speed VR output from the adder 40 is input to the reference torque calculator 47 as the vehicle body speed VB.
Then, the reference torque calculator 47 calculates a reference torque TG that can be transmitted without slipping on a road surface having a friction coefficient μ based on the vehicle body speed VB.

Then, the reference torque TG and the integral correction torque T
Subtraction with Sn is performed in a subtraction unit 48, and 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, the target torque TΦ is sent to the torque / throttle opening conversion unit 50 and converted into a sub-throttle opening Θs for generating the target torque TΦ, and the sub-throttle valve THs is changed according to the throttle opening Θs. It is controlled to open and close.

Incidentally, the wheel speed of the driven wheel output from the high vehicle speed selecting unit 37 having a larger value is subtracted from the wheel speed VFR of the driving wheel by the subtracting unit 55.
Is subtracted. Further, the subtracting section 56 subtracts the wheel speed of the driven wheel having the larger value from the output of the high vehicle speed selecting section 37 from the wheel speed VFL of the driving wheel. Therefore, the subtraction unit
By estimating the output of 55 and 56 to be small, even if a difference occurs on the left and right driven wheels due to the inner ring difference even during turning,
Prevents brake operation due to false slip detection and improves running stability.

The output of the subtractor 55 is multiplied by KB in the multiplier 57 (0 <
KB <1), the output of the subtraction unit 56 is multiplied by (1-KB) in the multiplication unit 58, and then added in the addition unit 59 to obtain the slip amount DVFR of the right driving wheel. At the same time,
The output of the subtraction unit 56 is multiplied by KB in the multiplication unit 60, the output of the subtraction unit 55 is multiplied by (1-KB) in the multiplication unit 61, and then added in the addition unit 62 to obtain the slip amount DVFL of the left driving wheel. It is said that As shown in FIG. 13, the variable KB changes according to the elapsed time from the start of the control of the traction control, and is set to "0.5" at the start of the control of the traction control, and becomes "0.8" as the control of the traction control progresses. Is set to approach. That is, when the slip of the driving wheels is reduced by the brake, both wheels can be simultaneously braked at the start of braking to reduce an uncomfortable steering wheel shock at the start of brake braking on a split road, for example. . The operation will be described when the brake control is continuously performed and KB becomes “0.8”. In this case, when one of the driving wheels slips, the other driving wheels recognize that a slip of only 20% of the one driving wheel has occurred, and perform the brake control. This is because if the brakes on the left and right drive wheels are made completely independent, the brake will be applied to only one drive wheel and the rotation will decrease, and the drive wheel on the opposite side will slip due to the action of the diff and the brake will be applied. This is because it is repeated, which is not preferable. Slip amount DV of the above right drive wheel
The FR is differentiated in the differentiator 63 to calculate its temporal change amount, that is, the slip acceleration GFR, and the slip amount DVFL of the left driving wheel is differentiated in the differentiator 64 to its temporal change amount, that is, the slip acceleration. GFL is calculated. Then, the slip acceleration GFR is sent to the brake fluid pressure change amount (ΔP) calculation section 65, and the GFR shown in FIG.
The change amount ΔP of the brake fluid pressure for suppressing the slip acceleration GFR is obtained with reference to the (GFL) -ΔP conversion map. Similarly, the slip acceleration GFL is sent to the brake fluid pressure change amount (ΔP) calculation unit 66, and the slip acceleration GFL is controlled by referring to the GFR (GFL) -ΔP conversion map shown in FIG. Brake fluid pressure change ΔP
Is required.

Incidentally, in FIG. 14, when the brake is applied at the time of turning, in order to strengthen the brake of the inner drive wheel,
A broken line a indicates the inner wheel side at the time of turning. In this way, when the vehicle is turning, the load is moved to the outer wheel side and the inner wheel side is more likely to slip. By making the change amount ΔP of the brake fluid pressure larger on the inner wheel side than on the outer wheel side, At times, it is possible to prevent the inner ring side from slipping. Any method can be used to determine whether the vehicle is turning, as long as it is a method of determining a turning state that is conventionally used.

Although the centripetal acceleration GY ′ in the centripetal acceleration computing unit 53 in the above embodiment is based on the wheel speed v1 on the inner wheel side, the invention is not limited to this, and the wheel speed v1 on the inner wheel side and the wheel speed v2 on the outer wheel side are compared. May be used as a reference, or the wheel speed v2 on the outer wheel side may be used as a reference.

For example, a case will be described in which the centripetal acceleration GY 'is calculated based on the average of the inner wheel speed v1 and the outer wheel speed v2. In this case, the centripetal acceleration GY ′ can be obtained by substituting v = v2 + v1 / 2, r = (r1 + Δr) / 2 into the equation (1) and transforming it using the equation (2), GY ′ = (v2 ² −v1 ² ) / 2 · Δr (5)

On the other hand, when using the wheel speed v2 on the outer wheel side as a reference, substituting v = v2, r = r1 + Δr into the above equation (1),
When transformed using the equation (2), GY ′ = (v2-v1) v2 · Δr (6)

Therefore, the centripetal acceleration based on the wheel speed v2 on the outer ring side
When the GY ′ is calculated, the centripetal acceleration GY ′ is estimated to be larger than the actual value. Therefore, by recognizing the slip amount DV ′ to be larger than the actual value, the target torque TΦ is estimated to be small and the wheel speed v1 on the inner wheel side is calculated. The engine output torque is smaller than that of the standard, and the lateral force is increased to improve the turning performance. Further, when the centripetal acceleration GY 'is calculated based on the average of the inner wheel speed v1 and the outer wheel speed v2, the centripetal acceleration GY' is calculated based on the inner wheel speed v1 as described above. Intermediate output control of the engine based on the case and the wheel speed v2 on the outer wheel side is performed, so that an intermediate characteristic that puts a specific gravity on both the driving force during turning and the turning performance can be obtained. .

[Advantages of the Invention] As described in detail above, according to the present invention, it is possible to provide an acceleration slip prevention device for a vehicle that suppresses the occurrence of slip during turning and can safely turn.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle acceleration slip prevention device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing control of the traction controller of FIG. 3 shows the relationship between the centripetal acceleration GY and the variable KG, FIG. 4 shows the relationship between the centripetal acceleration GY and the variable Kr, and FIG. 5 shows the relationship between the centripetal acceleration GY and the slip correction amount Vg. Figures 6 show the rate of change G of the centripetal acceleration over time.
And FIG. 7 to FIG. 12 showing the relationship between the slip correction amount Vd and the slip correction amount Vd.
The figure shows the relationship between the vehicle speed VB and the variable Kv, respectively.
FIG. 13 is a diagram showing a time change of the variable KB from the start of the brake control, and FIG. 14 is a time variation of the slip amount GFR (GF
L) and the amount of change in brake fluid pressure ΔP, FIG.
Fig. 5 shows the relationship between the slip ratio S, the friction coefficient μ between the tire and the road surface, and the lateral force (side force). Fig. 16 shows the turning radii r1, r and tread Δr when the vehicle is turning right.
It is the figure which showed. 11-14 Wheel speed sensor, 15 Traction controller, 45 TSn calculation section, 46 TPn calculation section, 47 Reference torque calculation section, 50 Torque / throttle opening degree conversion section, 53 ... a centripetal acceleration calculation unit, 54 ... a centripetal acceleration correction unit.

Claims (1)

[Claims] 1. A driven wheel speed sensor for detecting a wheel speed of a driven wheel of a vehicle, a drive wheel speed sensor for detecting a wheel speed of a drive wheel of the vehicle, and the driven wheel detected by the driven wheel speed sensor. The slip detection means for detecting the slip state amount indicating the magnitude of the slip occurring in the drive wheel based on the wheel speed of the drive wheel and the wheel speed of the drive wheel detected by the drive wheel speed sensor, and the drive wheel Braking means for braking and the braking means according to the slip state amount detected by the slip detecting means, and when the vehicle is in a turning state, the braking force on the inner wheel side of the left and right drive wheels is set to the slip state amount. A vehicle acceleration slip prevention device, comprising: a braking unit that corrects an increasing direction from a size corresponding to the above.