JP3161206B2 - Vehicle turning behavior 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 turning behavior control device for a vehicle, and more particularly to a turning operation of a vehicle in which the turning behavior of the vehicle is controlled so as to coincide with a target turning behavior determined in accordance with a driver's steering operation. The present invention relates to a behavior control device.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique of controlling turning behavior of a vehicle using a brake.

[0003] For example, in Japanese Patent Application Laid-Open No. 3-276852, a target yaw rate is set from a vehicle speed and a steering angle, and the braking force of each wheel is set so that the detected actual yaw rate of the vehicle body matches the target yaw rate. Is controlling.

[0004]

In the conventional apparatus, the target yaw rate is set uniformly from the steering angle and the vehicle speed.
If the driver performs excessively large steering, the excessive target yaw rate becomes the target value.Based on this, if the braking force control that matches the actual yaw rate to the excessive target yaw rate is performed, the vehicle traveling stability decreases. There was a problem of doing.

The present invention has been made in view of the above points, and by limiting the target value of the turning behavior, it is possible to prevent the target value from becoming excessive even when steering is performed excessively, and to achieve stable running. It is an object of the present invention to provide a turning behavior control device for a vehicle, which can perform the turning.

[0006]

According to a first aspect of the present invention, there is provided a vehicle turning behavior control apparatus for detecting a steering operation of a driver, as shown in a principle diagram of FIG. Means M1, target setting means M2 for setting a target value of the turning behavior of the vehicle according to the detected steering operation, turning behavior detecting means M3 for detecting the actual value of the turning behavior of the vehicle,
A road surface condition that detects the road surface μ, which is the road surface condition on which the vehicle runs
State detection means M6, and when the detected road surface μ is small,
A limiting means M4 for setting an upper limit value as the maximum value and limiting the turning behavior target value set by the target setting means M2 with the upper limit value, so that the actual value of the turning behavior coincides with the target value of the turning behavior. Control means M for controlling the turning behavior of the vehicle
5 is provided.

In the vehicle turning behavior control device according to a second aspect of the present invention, the target value of the turning behavior is a yaw rate.
The upper limit is set based on the value obtained by dividing the road μ by the vehicle speed.
Characterized in that that.

Further, in the turning behavior control device for a vehicle according to a third aspect of the present invention, the target value of the turning behavior is a lateral acceleration.
The upper limit is set to a larger value as the road surface μ increases.
Characterized in that it is. Further, the turning of the vehicle according to the fourth invention.
The behavior control device detects a driver's steering operation.
Detecting means for turning the vehicle in accordance with the detected steering operation;
Target setting means for setting the vehicle body side slip angle as a target value of movement
And a turning behavior detecting means for detecting an actual value of the turning behavior of the vehicle.
Step, vehicle speed detecting means for detecting vehicle speed, and detected vehicle speed
Is smaller, the upper limit is set as a larger value, and the target
The target value of the turning behavior set by the setting means is limited by the above upper limit
And the actual value of the turning behavior is determined by the turning behavior.
Control the turning behavior of the vehicle so that it matches the target value of the vehicle.
And control means .

[0009]

In the vehicle turning behavior control device according to the first aspect of the invention, the steering operation of the driver is detected by the steering operation detecting means M1, and the target of the turning behavior of the vehicle according to the driver's steering operation is detected by the target setting means M2. The value is set. On the other hand, the actual value of the turning behavior of the vehicle is detected by the turning behavior detecting means M3, and the road surface μ is detected by the road surface state detecting means M6.
And the road surface μ detected by the limiting means M4 is small.
In such a case, the upper limit is set as a small value. Control means M
5 controls the turning behavior of the vehicle such that the actual value of the turning behavior coincides with the target value of the turning behavior limited by the upper limit .

[0010]

[0011]

[0012]

FIG. 2 is a block diagram showing an embodiment of the apparatus according to the present invention. In the figure, when the brake pedal 10 is depressed, a hydraulic pressure is generated in each of the two pressurizing chambers of the master cylinder 12. Each pressurizing chamber of the master cylinder 12 has two-position switching valves 14 and 15
Connected to each. The two-position switching valve 14 has a main passage 16
, Two-position switching valves 17 and 1 corresponding to the right and left front wheels, respectively.
The two-position switching valves 15 are connected to the respective two-position switching valves 20 and 21 corresponding to the right and left rear wheels by a main passage 19.

The pump 25 has one end connected to a reservoir 26 and the other end connected to an accumulator 28 via a check valve 27. The brake fluid is supplied from the reservoir 26 to the hydraulic accumulator 28 and stored therein. . A relief valve 29 is provided between the pump 25 and the check valve 27.
Is provided.

The hydraulic accumulator 28 is connected to each of the linear hydraulic pressure control valves 31, 32, 33 and 34, and the discharge brake fluid of each of these control valves 31 to 34 is returned to the reservoir 26 through a passage 35. . Each of the linear hydraulic pressure control valves 31 to 34 is a two-position switching valve 17, 18, 20,
21 are connected to each other, and the two-position switching valves 17, 18,
20 and 21 are front right wheel 36, front left wheel 37, rear right wheel 3 respectively.
8. Wheel cylinders 41, 42, 4 of left rear wheel 39
3, 44, respectively.

An electronic control unit (ECU) 50 includes wheels 36
, A steering angle signal detecting the steering angle of the steering wheel, a yaw rate signal detecting the yaw rate of the vehicle, a pedaling force signal detecting the pedaling force of the berake pedal 10, and a load on the wheels 36 to 39. Wheel load signal that detected the vehicle, longitudinal G that detected the longitudinal acceleration of the vehicle
A signal, a lateral G signal detecting a lateral acceleration of the vehicle, a road surface μ signal detecting a friction coefficient of a road, and a vehicle body slip angle β signal detecting a vehicle slip angle are supplied. In addition,
The vehicle body side slip angle β is detected by detecting the vehicle body front-rear direction vehicle ground speed (Vx) and the vehicle sideways vehicle ground speed (Vy) using a vehicle speed sensor or the like and calculating β = tan ⁻¹ (Vy / Vx). Is done. The ECU 50 performs various calculations based on the signals, and supplies drive control signals to the drive circuits 51 and 52 as needed.

The drive circuit 51 supplies a drive signal to each of the linear hydraulic pressure control valves 31 to 34 based on the drive control signal to vary each brake fluid pressure, and the drive circuit 52 switches two positions based on the drive control signal. Valves 14, 15, 17, 18, 2
A drive signal is supplied to each of 0 and 21 to perform each position switching.

During normal driving, the ECU 50 controls
The position switching valves 14, 15, 17, 18, 20, 21 are shown in FIG.
And the hydraulic pressure of the master cylinder 12 corresponding to the depression force of the brake pedal 10 is changed to the wheel cylinder 4
1 to 44 to brake the wheels 36 to 39, respectively.

At the time of antilock brake (ABS) control and turning control, the two-position switching valves 14, 15, 17, 18, 20, 21 are controlled by the ECU 50 as shown in FIG.
Are switched to the positions opposite to the positions shown in FIG. 7, and the hydraulic pressures of the linear hydraulic pressure control valves 31 to 34 controlled by the ECU 50 are supplied to the wheel cylinders 41 to 44, and the wheels 36 to 39 are respectively braked.

FIG. 3 shows a flowchart of a first embodiment of the turning braking process executed by the ECU 50 of the device of the present invention. This processing is executed, for example, every 6 to 10 msec. In the figure,
In step S10, the steering angle θ, the vehicle speed V, the road surface μ, the yaw rate γ, the pedaling force F, and the wheel speeds Vw of the wheels 36 to 39 detected by the sensors are read. Note that the vehicle speed V is the value of the wheel 3
It may be obtained from the wheel speed of the driven wheel among 6 to 39. Step S10 corresponds to the steering operation detecting means M1, the turning behavior detecting means M3, the road surface state detecting means M6, and the vehicle speed detecting means M7. Here, the turning behavior is the yaw rate,
The steering operation is a steering operation performed by the driver, a parameter is a steering angle, and the road surface state is a road surface μ or the like.

In the next step S12, the brake pedal 10
Target braking force Bfr, Bfl, Brl, B
Calculate rr. The target braking force is obtained in one-to-one correspondence with the pedaling force F.

Next, step S as the target setting means M2
In step 14, the target yaw rate γ ^* is calculated from the steering angle θ and the vehicle speed V by the equation (1).

[0022]

(Equation 1)

Where ω_n, Ζ are the resonance frequency of the vehicle and the
Decay coefficient m is vehicle weight K_rIs the cornering power of the rear wheel L_fIs the front wheel base (from the center of gravity to the center of the front wheel axle)
L is the wheelbase (from the center of the front axle to the center of the rear axle)
A is a stability factor, N is a steering gear ratio, s is a Laplace operator. FIG.
θ and target yaw rate γ ^*Or the target lateral acceleration described later
Gy^*And the relationship. However, the target Yawley
G^*Product of vehicle speed V and target lateral acceleration Gy
^*Does not exceed the road surface μ.

Next, in step S16, the target yaw rate maximum value γmax ^* is calculated by referring to the map shown in FIG. 5 using V / μ obtained from the vehicle speed V and the road surface μ. By the way, when the vehicle body slip angle β is close to 0, sin β ≒ β,
Vehicle running is represented by the following equation.

Gy = ΔV · β + V · Δβ + V · γ (2) where Gy is the lateral acceleration, that is, the lateral G, ΔV is the differential value of the vehicle speed V, and Δβ is the differential value of the vehicle body slip angle β. Here, considering the steady circular turning motion, the first and second terms on the right side are both 0, which is expressed as Gy = V · γ, and Gy is the road surface μ.
Since it is not larger, the following equation is obtained.

Μ ≧ V · γ That is, γ ≦ μ / V, and the following equation is obtained.

Γmax ^* = μ / V (3) The map of γmax ^* shown in FIG. 5 is obtained from equation (3).

Next, at step S18, the target yaw rate γ^*
Target yaw rate maximum value γmax from the absolute value of^*Is bigger
Whether or not | γ^*| <Γmax^*If step S
Proceed to 22. ｜ γ^*| ≧ γmax^*If step S2
Target yaw rate maximum value γmax at 0^*The target yaw rate
Sign sign (γ^*) To add a new target yaw rate γ ^*
And set a guard at the target yaw rate, and then step
Proceed to S22. The above steps S16 to S20 are restricted
Corresponds to stage M4.

In step S22, a deviation Δγ between the target yaw rate γ ^* and the detected yaw rate γ is calculated. Next, in step S24, it is determined whether or not the ABS control is being performed.
If the control is not being performed, the process proceeds to step S26. If the ABS control is being performed, the process proceeds to step S34.

The yaw rate γ is positive in the counterclockwise direction as shown in FIG. In step S26, the left and right braking force difference B ₁ (= left wheel braking force−right wheel braking force) is obtained by referring to the map shown in FIG. 7 using the above-described yaw rate deviation Δγ. Next, in step S28, the target braking force Bfr, Bfl, Brr, Brl of each wheel is corrected by the following equation.

[0031] Bfr = Bfr-B in _{1 Bfl = Bfl + B 1 Brr} = Brr-B 1 Brl = Brl + B 1 then a value obtained by multiplying the yaw rate γ of the yaw rate deviation Δγ in step S30 with reference to the map shown in FIG. 8, control A power front-rear difference B ₂ (= rear wheel braking force−front wheel braking force) is obtained. Next, in step S32, the target braking force Bf of each wheel is calculated by the following equation.
r, Bfl, Brr, and Brl are corrected, and the flow advances to step S44.

Bfr = Bfr−B ₂ Bfl = Bfl−B ₂ Brr = Brr + B ₂ Brl = Brl + B _{2 In} steps S 26 and S 28, the deviation Δ of the yaw rate is obtained.
It is determined from γ whether the required correction moment is clockwise or counterclockwise. If this is counterclockwise (or clockwise), the target braking force of the left and right front wheels is increased (or decreased), and the right and front wheels are determined. Is reduced (or increased). In steps S30 and S32, whether the tendency is to drift out from Δγ × γ (Δγ × γ is positive) or to the spin tendency (Δγ × γ is negative)
If there is a tendency to drift out, the target braking force of the left and right rear wheels is increased, and the target braking force of the left and right front wheels is decreased to increase the rotational moment of the vehicle. The target braking force of the front wheels is increased, and the target braking forces of the right and left rear wheels are reduced to reduce the rotational moment of the vehicle.

If the ABS control is being performed, a slip ratio left / right difference S ₁ (= left wheel slip ratio−right wheel slip ratio) is determined in step S34 by using the yaw rate deviation Δγ and referring to the map shown in FIG. Next step S36 by the following equation by each and adding or subtracting the slip ratio difference between right and left S ₁ to the target slip ratio S ₀ corresponding to the pedal force F obtained in ABS control wheel target slip ratio Sfr, creating Sfl, Srr, the Srl .

[0034] shown in _{Sfr = S 0 -S 1 Sfl =} S 0 + S 1 Srr = S 0 -S 1 Srl = S 0 + S 1 then 8 with the value obtained by multiplying the yaw rate γ of the yaw rate deviation Δγ in step S38 Referring to the map, the difference S ₂ before and after the slip ratio (= rear wheel slip ratio−front wheel slip ratio)
Ask for. Next, in step S40, the target slip rates Sfr, Sfl, Srr, and Srl of each wheel are corrected by the following equation.

[0035] _{Sfr = Sfr-S 2 Sfl =} Sfl-S 2 Srr = Srr + S 2 Srl = Srl + S 2 above steps S34, S36 in the yaw rate deviation Δ
From γ, it is determined whether the required correction moment is clockwise or counterclockwise. If this is counterclockwise (or clockwise), the target slip ratio of the front and rear wheels on the left is increased (or decreased) and the front and rear wheels on the right are calculated. Is reduced (or increased). Further, in steps S30 and S32, whether the drift tendency is from Δγ × γ (Δγ × γ is positive) or the tendency is spinning (Δγ × γ).
γ is negative), and if the vehicle tends to drift out, the target slip ratio of the left and right rear wheels is increased, and the target slip ratio of the left and right front wheels is reduced to increase the rotational moment of the vehicle. If so, the target slip ratios of the left and right front wheels are increased, and the target slip ratios of the left and right rear wheels are reduced to reduce the rotational moment of the vehicle. If the slip ratio is reduced, the lateral force generated on the wheel is increased, so that the rotational moment of the vehicle is controlled as described above, and the tendency to drift out and the tendency to spin are eliminated.

Next, in step S42, the respective target braking forces Bfr, Bfl, Brr, Brl of the respective wheels for obtaining the target slip rates Sfr, Sfl, Srr, Srl of the respective wheels are calculated.
Go to 44.

In step S44, the target braking forces Bfr, Bf
Two-position switching valves 14, 15, 17, 18, 20, 21 so that brake fluid pressure is applied to wheel cylinders 41 to 44 of wheels 36 to 39 according to l, Brr and Brl, respectively.
Then, the linear hydraulic pressure control valves 31 to 34 are driven, and the process ends. Steps S26 to S42 correspond to the control unit M5.

When the ABS control is not being performed, step S
The reason for calculating the braking force in 26 to S32 is that the slope of the increase in the braking force with respect to the increase in the slip ratio is steep in an area where the slip ratio is small until the braking force in the front-rear direction of the vehicle is maximized. When the corresponding target braking force is obtained, the deviation becomes large, and it becomes difficult to perform high-precision braking force control. Therefore, the braking force is directly obtained.

FIG. 9 shows a block diagram of the processing shown in FIG. In the figure, a target model 150 obtains a target yaw rate γ ^* guarded by a maximum value γmax ^* from a steering angle θ, a vehicle speed V, and a road surface μ. The mixer 151 outputs a deviation Δγ between the target yaw rate γ ^* and the detected yaw rate γ. The map 152 reads the difference between the left and right of the braking force or the slip ratio according to Δγ, and the map 153 reads the difference between before and after the braking force or the slip ratio according to γ and Δγ. The map 154 reads out the target braking force or the target slip ratio of each wheel according to the pedaling force F.

The left / right difference, front / rear difference, and target value read from each of the maps 152, 153, and 154 are stored in the mixer 155.
And the target braking force of each wheel is obtained, and the braking force actuator of each wheel of the vehicle 156 is controlled according to the target braking force.

[0041] Thus, to calculate the target yaw rate maximum value .gamma.max ^* from the vehicle speed V and the road μ In the above embodiment, the target yaw rate gamma ^* is the target yaw rate maximum value .gamma.max ^*
, Especially on the road surface μ
Is small, it is possible to prevent the target yaw rate γ ^{* from} becoming excessively large, thereby preventing the running stability from being lowered due to the target yaw rate being excessively large.

FIG. 10 shows a flowchart of a second embodiment of the turning braking process. 3, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 10, the braking force of each wheel is controlled using the lateral acceleration Gy instead of the yaw rate γ.

In FIG. 10, in step S110, the steering angle θ, the vehicle speed V, the road surface μ, the lateral acceleration Gy, the pedaling force F, and the wheel speed Vw of each of the wheels 36 to 39 detected by each sensor.
Read each one.

In the next step S12, the brake pedal 10
Target braking force Bfr, Bfl, Brl, B
Calculate rr.

Next, at step S114, the steering angle θ and the vehicle speed V
, The target lateral acceleration Gy ^* is calculated by the equation (4).

[0046]

(Equation 2)

Here, I is the moment of inertia of the vehicle _Lr is the rear wheel base (the distance from the center of gravity to the center of the rear wheel axle) Next, in step S116, the map shown in FIG.
To calculate a target lateral acceleration maximum value Gymax ^* . The map of Gymax ^* shown in FIG. 11 is obtained because the lateral acceleration does not become larger than the road surface μ.

Next, in step S118, the target lateral acceleration maximum value Gymax ^{* is} calculated from the absolute value of the target lateral acceleration Gy ^{* .}
Is larger or smaller, and if | Gy ^* | <Gymax ^* , the process proceeds to step S122. | Gy ^* | ≧ Gymax ^*
In step S120, the sign (Gy ^* ) of the target lateral acceleration is added to Gymax ^* in step S120 to obtain a new target lateral acceleration Gy ^*, and a guard is provided at the target lateral acceleration.
Thereafter, the process proceeds to step S122. Step S11 above
6 to S120 correspond to the control unit M4.

In step S122, the target lateral acceleration G
A deviation ΔGy between y ^* and the detected lateral acceleration Gy is calculated. Next, in step S24, it is determined whether or not the ABS control is being performed. If the ABS control is not being performed, the process proceeds to step S126. If the ABS control is being performed, the process proceeds to step S134.

The lateral acceleration Gy is positive when leftward as shown in FIG. In step S126, a braking force left / right difference B ₁ (= left wheel braking force−right wheel braking force) is obtained by referring to the map shown in FIG. 7 using the above-described lateral acceleration deviation ΔGy. Furthermore, step S following step S28
At 130, the lateral acceleration deviation Gy is added to the lateral acceleration deviation ΔGy.
The braking force front-rear difference B ₂ (= rear wheel braking force-front wheel braking force) is determined by referring to the map shown in FIG.

[0051] Using the deviation ΔGy lateral step S134 direction acceleration with reference to the map shown in FIG. 7, obtaining a slip rate right difference S _1. Moreover the value obtained by multiplying the lateral acceleration Gy by referring to a map shown in FIG. 8 in the next step S138 the lateral acceleration deviation ΔGy step S36, obtains the slip ratio difference before and after S _2.

As described above, in the embodiment, the target lateral acceleration maximum value Gymax ^* is calculated from the vehicle speed V and the road surface μ so that the target lateral acceleration Gy ^* does not exceed the target lateral acceleration maximum value Gymax ^*. Because it is guarded,
In particular, even when the road surface μ is small, it is possible to prevent the target lateral acceleration Gy ^{* from} becoming excessive, thereby preventing the running stability from being reduced due to the excessive target lateral acceleration.

FIG. 12 shows a flowchart of the third embodiment of the turning braking process. 3, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 12, the braking force of each wheel is controlled using the vehicle body side slip angle β instead of the yaw rate γ.

In FIG. 12, in step S210, the steering angle θ, the vehicle speed V, the road surface μ, the vehicle body side slip angle β, the pedaling force F, and the wheel speeds Vw of the wheels 36 to 39 detected by the respective sensors are read. The vehicle speed V may be obtained from the wheel speed of the driven wheels among the wheels 36 to 39.

In the next step S212, the breakey pedal 1
From the pedaling force F of 0, the target braking forces Bfr, Bfl, Brl,
Calculate Brr.

Next, in step S214, the steering angle θ and the vehicle speed V
From Equation (5), the target vehicle body slip angle β ^* is calculated.

[0057]

(Equation 3)

FIG. 13 shows the relationship between the steering angle θ expressed by the equation (5) and the target vehicle body slip angle β ^* at an arbitrary vehicle speed V. However, the target vehicle sideslip angle β ^* is the road surface μ
Never exceed.

Next, in step S216, the map shown in FIG. 14 is referred to using the vehicle speed V, and the target vehicle body slip angle maximum value βmax ^* is calculated.

Next, it is determined whether the target vehicle body slip angle beta ^* absolute value than the target vehicle body slip angle maximum value .beta.max ^* is large at step S218, | β ^* | For <.beta.max ^* proceeds to step S222 . If | β ^* | ≧ βmax ^* , in step S220, the sign (β ^* ) of the target vehicle body slip angle is added to the maximum target vehicle body skid angle βmax ^* to obtain a new target vehicle body skid angle β ^*. A guard is provided for the sideslip angle, and then the process proceeds to step S222.

In step S222, the target vehicle body slip angle β
The deviation Δβ between the detected vehicle body slip angle β and ^* is calculated. Next, it is determined in step S24 whether or not the ABS control is being performed. If the ABS control is not being performed, the process proceeds to step S226,
If the ABS control is being performed, the process proceeds to step S234.

As shown in FIG. 6, the vehicle body skid angle β is positive when turned rightward. In step S226, using the above-described deviation Δβ of the vehicle body side slip angle, referring to the map shown in FIG. 7, the braking force left / right difference B ₁ (= left wheel braking force−right wheel braking force).
Ask for. Step S230 following step S28
With reference to the map shown in FIG. 8, a value obtained by multiplying the deviation Δβ of the vehicle body side slip angle by the vehicle body side slip angle β, the braking force front-back difference B ₂ (=
Rear wheel braking force-front wheel braking force).

In step S 234, the slip ratio left / right difference S ₁ is obtained by referring to the map shown in FIG. 7 using the deviation ΔB of the vehicle body side slip angle. Further, in step S238 following step S36, the deviation Δβ of the vehicle body side slip angle is added to the vehicle body side slip angle β.
Referring to the map shown in FIG 8 with the value obtained by multiplying the obtained slip ratio difference before and after S _2.

FIG. 15 shows a block diagram of the processing shown in FIG. In the figure, the target model 16 obtains a target vehicle body slip angle β ^* guarded by the maximum value βmax ^* from the steering angle θ and the vehicle speed V. The mixer 161 outputs a deviation Δβ between the target vehicle body slip angle β ^* and the detected vehicle body slip angle β. The map 162 reads the difference between left and right of the braking force or the slip ratio according to Δβ, and the map 163 reads the difference between before and after the braking force or the slip ratio according to γ and Δγ. The map 164 reads out the target braking force or the target slip ratio of each wheel according to the pedaling force F.

The left / right difference, front / rear difference, and target value read from each of the maps 162, 163, and 164 are stored in the mixer 165.
And the target braking force of each wheel is obtained, and the braking actuator of each wheel of the vehicle 166 is controlled according to the target braking force.

As described above, in the above embodiment, the target vehicle body slip angle maximum value βmax ^* is calculated from the vehicle speed V, and the guard is set so that the target vehicle body slip angle β ^* does not exceed the target vehicle body slip angle maximum value βmax ^*. I'm running. Even at the same body slip angle, the higher the vehicle speed, the lower the running stability.
The target vehicle body slip angle β ^* is limited by the vehicle speed. Therefore, even when the vehicle speed is high, the target vehicle body slip angle β ^* is prevented from becoming excessively large, thereby preventing the running stability from being reduced due to the vehicle body skid angle being excessively large.

Although the brake by wire system has been described in the above embodiment, the conventional A
Applicable to BS system. Before the ABS control, the proportioning valve or LSPV
(Load sensing proportioning valve)
The same can be applied to any system that can control the front / rear or left / right braking force distribution by changing the characteristics of the above.

In the above embodiment, an example in which the front and rear and left and right braking forces or slip rates are controlled has been described. However, the present invention can also be applied to a system for controlling only the front and rear or left and right braking forces or slip rates.

Further, not only the braking force of each vehicle is controlled, but also the 4WS for controlling the rear wheel steering angle independently of the front wheels, or the distribution of the roll stiffness of each wheel is independently controlled, so that the steering characteristic, that is, the turning behavior is obtained. The characteristic may be variably controlled, and is not limited to the above embodiment.

In the above embodiment, the maximum values of the target lateral acceleration and the target vehicle body slip angle are set in accordance with the road surface μ and the vehicle speed V. However, the maximum value of the target may be a fixed value. The present invention is not limited to the above embodiment.

[0071]

As described above, according to the vehicle turning behavior control device of the first invention, the turning behavior of the vehicle is controlled such that the actual value of the turning behavior coincides with the target value of the restricted turning behavior. , The target value of the turning behavior is small when the road surface μ is small.
As the target value of the excessive turning behavior is set, the actual value of the turning behavior is prevented from becoming excessive.
The actual value of the turning behavior is excessive due to the setting of the target value
And therefore, especially on low μ roads
Row stability is improved.

Further , according to the vehicle turning behavior control device of the second invention, the target value of the turning behavior is the yaw rate.
The upper limit is set based on the value obtained by dividing the road surface μ by the vehicle speed.
Driving stability, especially on low μ roads.
You. Further, according to the turning behavior control device for a vehicle of the third invention,
For example, the target value of the turning behavior is a lateral acceleration,
The upper limit is set to a larger value as the road surface μ increases
Therefore, running stability particularly on a low μ road is improved.

Further, according to the vehicle turning behavior control device of the fourth invention, the vehicle body side slip angle as the target value of the turning behavior is restricted according to the vehicle speed. Setting the value prevents the actual value of the turning behavior from becoming excessive. Therefore, the running stability especially at high speed is improved.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of the device of the present invention.

FIG. 3 is a flowchart of a turning braking process.

FIG. 4 is a diagram showing a relationship between a steering angle and a target yaw rate or a target lateral G;

FIG. 5 is a diagram showing a map.

FIG. 6 is a diagram for explaining a yaw rate, a lateral G, and a vehicle body side slip angle.

FIG. 7 is a diagram showing a map.

FIG. 8 is a diagram showing a map.

FIG. 9 is a block diagram of the process of FIG. 3;

FIG. 10 is a flowchart of a turning braking process.

FIG. 11 is a diagram showing a map.

FIG. 12 is a flowchart of a turning braking process.

FIG. 13 is a diagram showing a relationship between a steering angle and a vehicle body side slip angle.

FIG. 14 is a diagram showing a map.

FIG. 15 is a block diagram of the processing of FIG. 12;

[Explanation of symbols]

 Reference Signs List 10 brake pedal 12 master cylinder 14, 15, 17, 18, 20, 21 2 position switching valve 25 pump 26 reverser 27 check valve 28 hydraulic accumulator 31-34 linear hydraulic pressure control valve 36-39 wheels 41-44 wheel cylinder Reference Signs List 50 electronic control unit 51, 52 drive circuit M1 steering operation detecting means M2 target setting means M3 turning behavior detecting means M4 limiting means M5 control means M6 road surface state detecting means M7 vehicle speed detecting means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60T 8/58 B60T 8/24 B60G 17/015 B62D 6/00 B60K 17/348

Claims (4)

(57) [Claims] 1. A steering operation detection for detecting a driver's steering operation.
And the target value of the turning behavior of the vehicle according to the detected steering operation.
Target setting means for setting, and turning behavior detecting means for detecting an actual value of the turning behavior of the vehicle
When,A road surface condition that detects the road surface μ, which is the road surface condition on which the vehicle runs
State detection means; When the detected road μ is small, the upper limit is set as a small value.
Set The target value of the turning behavior set by the target setting means
ToAbove upper limitAnd the actual value of the turning behavior coincides with the target value of the turning behavior.
Control means for controlling the turning behavior of the vehicle so that
A turning behavior control device for a vehicle, comprising: 2. The turning behavior control device for a vehicle according to claim 1, wherein the target value of the turning behavior is a yaw rate, and the upper limit value is set.
Is a vehicle turning behavior control device set based on a value obtained by dividing a road surface μ by a vehicle speed . 3. The turning behavior control device for a vehicle according to claim 1, wherein the target value of the turning behavior is a lateral acceleration.
The value is set to a larger value as the road surface μ becomes larger.
A turning behavior control device for a vehicle, comprising: (4)Steering operation detection to detect driver's steering operation
Delivery means, The target value of the turning behavior of the vehicle according to the detected steering operation and
Target setting means for setting the vehicle body side slip angle by Turning behavior detection means for detecting the actual value of the turning behavior of the vehicle
When, Vehicle speed detecting means for detecting a vehicle speed; The lower the detected vehicle speed, the larger the upper limit.
The target value of the turning behavior set by the target setting means.
Limiting means for limiting with the upper limit, The actual value of the turning behavior matches the target value of the turning behavior.
Control means for controlling the turning behavior of the vehicle so that
Vehicle turning behavior control device characterized by the above-mentioned. .