JP3218885B2 - Vehicle 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 behavior control device for suppressing and reducing undesired behavior such as drift-out and spin during turning of a vehicle such as an automobile, and more particularly, to controlling a braking force of a wheel. The present invention relates to a behavior control device that suppresses and reduces undesirable turning behavior.

[0002]

2. Description of the Related Art As one of devices for controlling the behavior of a vehicle such as an automobile at the time of turning, for example, Japanese Patent Application Laid-Open No. Hei 3-4545.
As disclosed in Japanese Patent Publication No. 3 (2003), a steering amount detecting means, a vehicle speed detecting means, a yaw rate detecting means, a limit vehicle speed detecting means for obtaining a tire grip limit vehicle speed according to the steering amount, a steering amount and a tire grip The vehicle has target yaw rate setting means for obtaining a target yaw rate corresponding to a limit vehicle speed, and braking means provided for each wheel. When the vehicle speed exceeds the tire grip limit vehicle speed, the yaw rate approaches the target yaw rate. 2. Description of the Related Art A behavior control device configured to control a braking force of a turning inner wheel and an outer wheel so that a vehicle speed decreases to a limit vehicle speed is conventionally known.

According to such a behavior control device, the vehicle can always be run in the grip area of the tires, and the yaw rate is prevented from exceeding the target yaw rate, thereby undesirably causing the vehicle to spin or drift out. Turning behavior can be prevented.

[0004]

In the conventional behavior control device described in the above publication, the braking force applied to each wheel is determined according to the deviation between the detected actual yaw rate and the target yaw rate. However, the magnitude of the required braking force varies depending on the friction coefficient μ of the road surface and the braking operation by the driver, etc. There is a problem that an optimum anti-spin moment cannot be generated due to a difference in braking force between the vehicle and the turning behavior of the vehicle cannot be satisfactorily suppressed.

The above problem is not limited to the case where the braking force is determined in accordance with the deviation between the actual yaw rate and the target yaw rate. Since the maximum value of the slip ratio, that is, the upper limit of the target slip ratio also changes depending on the friction coefficient of the road surface, etc., the predetermined wheel control required to stabilize the turning behavior according to the spin state amount indicating the turning behavior of the vehicle. The above-described problem also occurs when the target slip ratio corresponding to the power is calculated and the braking pressure of the predetermined wheel is controlled so that the wheel speed of the predetermined wheel becomes the target slip ratio.

The present invention has been made in view of the above-described problems in the conventional behavior control device, and a main object of the present invention is to provide an optimal control in accordance with a vehicle running condition such as a road surface friction coefficient. By optimizing the behavior control amount so as to generate the anti-spin moment of the vehicle, the turning behavior of the vehicle is controlled even better.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the main object as described above is a behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle; handed necessary to stabilize the turning behavior Te
It calculates a target slip rate corresponding to the braking force of Kaigairin, the behavior control device of a vehicle and a behavior control means the slip ratio of the turning outer wheel to control the braking pressure of the turning outer so as to be the target slip ratio A slope estimating means for estimating a slope of a linear region of a μ-S characteristic between a road surface and the turning outer wheel; and setting the target slip ratio so as to decrease as the estimated slope of the linear region increases. A vehicle behavior control device comprising: a target slip ratio correction unit for correcting a vehicle; and a behavior estimation unit for estimating a spin state based on a spin state amount indicating a turning behavior of the vehicle. If, calculates a target slip rate corresponding to the braking force of the outer turning wheel required to stabilize the turning behavior according to the spin state quantity, the slip ratio of the turning outer wheel becomes the target slip ratio At a behavior control device of a vehicle and a behavior control means for controlling the braking pressure of the turning outer wheel, the turning outer against the load of the wheel as a reference of the slip rate calculating
A vehicle behavior control device comprising: means for detecting a ratio of wheel loads; and target slip ratio correction means for correcting the target slip ratio so as to decrease as the load ratio increases. And a behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of the vehicle, and a braking force of a turning outer wheel necessary for stabilizing the turning behavior according to the spin state quantity. It calculates the corresponding target slip ratio, the slip ratio of the turning outer wheel at a the behavior control device of a vehicle and a behavior control means for controlling the braking pressure of the turning outer so as to be the target slip ratio, the friction of the road surface 5. A vehicle behavior control device comprising: means for detecting a coefficient; and means for setting an upper limit value of the target slip ratio so as to increase as the friction coefficient of the road surface decreases. ), A behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle equipped with an ABS device, and a braking force of a turning outer wheel necessary for stabilizing the turning behavior according to the spin state quantity at a behavior control device of a vehicle and a corresponding calculates a target slip rate, behavior control means the slip ratio of the turning outer wheel to control the braking pressure of the turning outer so as to be the target slip rate, the target Means for detecting whether or not the inner turning wheel on the front wheel side, which is a reference of the slip ratio calculation, is controlled by the ABS device; and setting the upper limit of the target slip ratio when the turning inner wheel is controlled by the ABS device. A vehicle behavior control device comprising: means for setting the vehicle speed to a small value; and a spin state control device based on a spin state quantity indicating a turning behavior of the vehicle. A behavior estimating means for estimating, the At a behavior control device of a vehicle and a behavior control means for stabilizing the control and turning behavior of the brake pressure of the turning outer wheel in response to the spin state quantity, the braking operation by the driver means for detecting the turning outer or the like to increase gradient of the braking pressure of the wheel other than the turning outer wheel is smaller than the pressure increase gradient of the braking pressure of the turning outer wheel when the braking operation is being performed by the driver Means for adjusting a braking pressure of a wheel other than the turning outer wheel , or a turning behavior of the vehicle.
Of spin state estimation based on spin state quantity
Estimating means and stable turning behavior according to the spin amount
Target slip corresponding to the braking force of the turning outer wheel necessary for
The slip rate of the turning outer wheel is calculated as the target slip.
A control method for controlling the braking pressure of the turning outer wheel so as to achieve a lip ratio.
In a vehicle behavior control device having motion control means,
The friction coefficient of the road surface between the vehicle and the turning outer wheel
Friction coefficient estimating means, and the estimated friction coefficient of the road surface
The target slip ratio is corrected so that it becomes smaller as
Target slip rate correction means
This is achieved by a vehicle behavior control device (the configuration of claim 7) .

According to the present invention, in order to effectively achieve the above-described main object, in the vehicle behavior control device according to the present invention, the inclination estimating means is adapted to the slip angle of the turning outer wheel . It is configured to estimate the slope of the linear region for the μ-S characteristic (claim 2). Also according to the invention
In order to achieve the above-mentioned main task effectively, the present invention will be described in claim 7.
In the configuration of the above, the friction coefficient estimating means may
Estimate the coefficient of friction of the road surface considering the slip angle.
(Configuration of Claim 8).

[0009]

In general, the μ-S characteristic between the road surface and the wheels changes depending on the surface properties of the road surface. For example, as shown in FIG. 14, the slope of the linear region of the μ-S characteristic is determined by the coefficient of friction of the road surface. The higher, the larger. Therefore, assuming a certain μ-S characteristic, the target slip ratio (So
), The braking pressure of the turning outer wheel is controlled so that the wheel speed of the turning outer wheel becomes the target slip ratio. However, as shown in FIG. 15, when the friction coefficient μ of the road surface is high, the frictional force F of the wheel is high. Becomes higher than the required value Fo, and conversely, when the friction coefficient of the road surface is low, the frictional force of the wheel becomes lower than the required value, and an optimum anti-spin moment cannot be generated.

According to the configuration of the first aspect, the road surface and the turning
The inclination of the linear region of the μ-S characteristic between the outer wheel and the outer wheel is estimated by the inclination estimating means, and the target slip ratio is corrected by the target slip ratio correcting means so that the larger the estimated inclination of the linear region becomes, the smaller the inclination becomes. Therefore, even if the surface texture of the road surface changes as the vehicle travels, thereby changing the slope of the linear region of the μ-S characteristic, the braking force of the turning outer wheel is accurately adjusted to a value required to stabilize the turning behavior. , And an optimum anti-spin moment is generated irrespective of the change in the surface properties of the road surface, whereby the turning behavior of the vehicle is well controlled.

The slope of the linear region of the μ-S characteristic is equal to the ratio μ / S of the friction coefficient of the road surface to the slip ratio, and the friction coefficient μ of the road surface is determined by the inertia force (in the horizontal direction) of the vehicle body during turning behavior control. Since it is proportional to the magnitude of the acceleration, the inclination estimating means may be configured to estimate the inclination of the linear region based on, for example, the ratio of the magnitude of the horizontal acceleration of the vehicle body to the slip ratio S.

[0012] Further, in general, μ-
The S characteristic varies depending on the slip angle α of the wheel as shown in FIG. 16, for example, even if the road surface and the wheel have the same surface properties. Therefore, μ-S for a certain slip angle
Even if the target slip ratio is calculated according to the spin state amount based on the characteristics and the braking pressure of the turning outer wheel is controlled so that the slip ratio of the turning outer wheel becomes the target slip ratio, the actual slip of the turning outer wheel is maintained .
If the lip angle is different from a preset slip angle,
In such a case, an optimum anti-spin moment cannot be generated.

According to the configuration of the second aspect, the first aspect is provided.
Since the inclination estimating means is configured to estimate the inclination of the linear region with respect to the μ-S characteristic according to the slip angle of the turning outer wheel , the inclination estimating means is configured to adjust the inclination of the turning outer wheel during turning of the vehicle. In accordance with the slip angle, the braking force of the wheel is accurately controlled to a value required to stabilize the turning behavior, and an optimum anti-spin moment is generated regardless of the change in the slip angle of the turning outer wheel . The turning behavior is well controlled.

In general, the braking force of the vehicle, that is, the frictional force between the road surface and the wheels, changes depending on the load on the wheels even if the road surface and the surface characteristics of the wheels are the same. The spin moment also changes due to a change in the ratio of the load of the turning outer wheel to the load of the wheel serving as a reference for the slip ratio calculation due to the load movement accompanying the turning or braking of the vehicle.

According to the third aspect of the present invention, the ratio of the load of the turning outer wheel to the load of the wheel, which is a reference for the calculation of the slip ratio, is detected, and the higher the load ratio, the smaller the target slip ratio becomes. Since it is corrected by the rate correction means, it is caused by the load movement accompanying the turning and braking of the vehicle.
Regardless of the change in the load of the turning outer wheel and the wheel which is the reference for the slip ratio calculation, the braking force of those wheels is accurately controlled to a value necessary to stabilize the turning behavior, and the actually generated anti-spin moment is reduced. Accurately controlled, whereby the turning behavior of the vehicle is well controlled.

In general, when the friction coefficient of the road surface is high, the braking force of the wheels also increases, and an effective anti-spin moment is generated. Therefore, it is not necessary to set the target slip ratio to a high value. When the target slip rate is low, the lateral force of the wheel is low and the spin moment acting on the vehicle body is small, but the braking force and the anti-spin moment of the wheel also become low. There is a possibility that the behavior cannot be properly performed. In general, as the friction coefficient of the road surface increases, the negative gradient in the region above the peak value of the μ-S characteristic increases, so that if the target slip ratio is calculated to be high, hunting is likely to occur in the control of the braking pressure of the turning outer wheel. Become.

According to the above configuration, the friction coefficient of the road surface is detected, and the upper limit of the target slip ratio is set so as to increase as the friction coefficient of the road surface decreases, so that the friction coefficient of the road surface increases. Occasionally, an effective anti-spin moment is generated without hindrance, whereby the turning behavior of the vehicle is well controlled, and the negative gradient of the turning outer wheel is increased due to a large negative gradient in the region above the peak value of the μ-S characteristic. Hunting is surely prevented from occurring in the control of the braking pressure,
Since the target slip ratio of the turning outer wheel can be set high when the friction coefficient of the road surface is low, a sufficient anti-spin moment is generated, and the turning behavior of the vehicle is reliably controlled.

Before the reference for the calculation of the target slip ratio
Even when the turning inner wheel on the wheel side is controlled by an ABS (anti-lock brake system) device, that is, when the actual slip ratio of the turning inner wheel on the front wheel side is high, the turning behavior according to the spin state amount as it is. When the target slip ratio corresponding to the braking force of the turning outer wheel required to stabilize the vehicle is calculated, the target slip ratio becomes excessively high, and the appropriate anti-spin moment required to stabilize the turning behavior of the vehicle is calculated. Hunting tends to occur in the control of the braking pressure of the turning outer wheel, which cannot be generated, and which is caused by the negative gradient in the region above the peak value of the μ-S characteristic.

According to the above-mentioned arrangement of claim 5, turning inner front wheel as a reference for calculation of the target slip ratio is whether or not it is controlled by the ABS device is detected, the front wheel-handed <br/> Turning when the pronation wheel is controlled by the ABS device
Since the upper limit of the target slip ratio of the outer wheel is set to a small value, it is possible to prevent the occurrence of an appropriate anti-spin moment due to an excessive slip ratio of the turning outer wheel, and to prevent the peak of the μ-S characteristic from being generated. The hunting of the control of the braking pressure of the turning outer wheel due to the negative gradient in the region not less than the value is also prevented.

In the case where a sudden braking operation is performed by the driver and the braking pressure of the wheels other than the turning outer wheel whose braking pressure is controlled is sharply increased, the turning by the behavior control is performed.
Towards the pressure increase gradient of the revolving outer ring other wheel the braking pressure than the pressure increase gradient of the outer ring of the braking pressure is increased, the reverse moment the anti-spin moment required to stabilize the turning behavior of the for vehicles Occurs, and the turning behavior of the vehicle cannot be stabilized.

According to the above construction, the braking operation by the driver is detected, and when the braking operation is performed by the driver, the braking pressure of the wheels other than the turning outer wheel whose braking pressure is controlled is increased. since pressure gradient braking pressure of the wheel of the revolving outer or revolving outer ring than <br/> out to be smaller than the pressure increase gradient of the braking pressure of the revolving outer ring is adjusted, sudden braking operation by the driver be performed, greater than the pressure increase gradient of the pressure increase gradient is always revolving outer ring than the wheel braking pressure turning outer <br/> braking pressure brake pressure is controlled, thereby stabilizing the turning behavior The anti-spin moment required for turning is reliably generated, and the turning behavior is reliably stabilized. Also mentioned above
According to the configuration of claim 7, between the road surface and the turning outer wheel,
The friction coefficient of the road surface is estimated by the friction coefficient estimation means,
The larger the estimated coefficient of friction of the road surface, the smaller
The target slip ratio is corrected by the target slip ratio corrector.
Therefore, similar to the case of the above-described configuration of claim 1, traveling
As a result, the surface properties of the road surface change, which results in friction of the road surface.
Even if the coefficient changes, the braking force of the turning outer wheel stabilizes the turning behavior
Is precisely controlled to the value required for
Optimal antispin moment is generated regardless of changes in
As a result, the turning behavior of the vehicle is well controlled. Ma
According to the configuration of claim 8 described above, in the configuration of claim 7,
Therefore, the friction coefficient estimating means considers the slip angle of the
It is configured to estimate the coefficient of friction of the road surface
As in the case of the above-described claim 2, when the vehicle is turning,
The braking force of the turning outer wheel
It is precisely controlled to the value required to stabilize turning behavior,
Optimal anti-spin regardless of changes in the slip angle of the turning outer wheel
Moment is generated, which causes the turning behavior of the vehicle
Well controlled.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 1 is a schematic diagram showing a vehicle braking device to which the behavior control device according to the present invention is applied and an electric control device thereof.

In FIG. 1, a braking device 10 includes a master cylinder 14 for pumping brake oil from first and second ports in response to a depression operation of a brake pedal 12 by a driver, and an oil pressure in the master cylinder. And a hydraulic booster 16 for increasing the brake oil to a pressure (regulator pressure) corresponding to the pressure. Master cylinder 1
The first port 4 is a brake hydraulic control conduit 18 for the front wheels.
The brake hydraulic control devices 20 and 22 for the left and right front wheels
The second port is connected to a three-port two-position switching type electromagnetic control valve 28 for the right and left rear wheels by a rear wheel brake hydraulic control conduit 26 having a proportional valve 24 on the way. The control valve 28 is connected by a conduit 30 to a brake hydraulic control device 32 for the left rear wheel and a brake hydraulic control device 34 for the right rear wheel.

The braking device 10 has an oil pump 40 which pumps up brake oil stored in the reservoir 36 and supplies it to the high-pressure conduit 38 as high-pressure oil. The high-pressure conduit 38 is connected to the hydro booster 16, and is also connected to a front-wheel switching valve 42 and a rear-wheel switching valve 44.
An accumulator 46 that accumulates high-pressure oil discharged from the accumulator as an accumulator pressure is connected. As shown, the switching valves 42 and 44 are also three-port two-position switching type electromagnetic switching valves.

The left and right front wheel brake hydraulic pressure control devices 20 and 22 include wheel cylinders 48FL and 48FR for controlling the braking force on the corresponding wheels, three-port two-position switching type electromagnetic control valves 50FL and 50FR, and a reservoir. Low pressure conduit 5 as return passage connected to 36
The normally open solenoid-operated on-off valves 54FL and 54FR and the normally-closed electromagnetic on-off valves 56FL and 56FL provided in the middle of the regulator pressure supply conduit 53 connected between the hydraulic pump 2 and the discharge port of the hydro booster 16. 56FR. The regulator pressure supply conduit 53 between the on-off valves 54FL, 54FR and the on-off valves 56FL, 56FR respectively has connection conduits 58FL, 58
FR is connected to control valves 50FL and 50FR.

The brake hydraulic control device 32 for the left and right rear wheels,
Reference numeral 34 denotes a normally-open electromagnetic on-off valve 60RL, 60 provided between the control valve 28 and the low-pressure conduit 52 in the middle of the conduit 30.
RR and normally closed solenoid-operated on-off valves 62RL, 62RR, and wheel cylinders 64RL, 64RR for controlling braking force on the corresponding wheels, respectively.
RL and 64RR are connected to the conduit 30 between the on-off valves 60RL and 60RR and the on-off valves 62RL and 62RR by connecting conduits 66RL and 66RR, respectively.

The control valves 50FL and 50FR are respectively a brake hydraulic control conduit 18 for the front wheels and a wheel cylinder 48FL.
And 48FR and wheel cylinder 48FL
, 48FR and the connection conduits 58FL and 58FR, the first position shown in the figure, the brake hydraulic control conduit 18 and the wheel cylinders 48FL and 48FR are disconnected, and the wheel cylinders 48FL and 48FR are connected to the connection conduit 58FL.
, And 58FR.

A regulator pressure supply conduit 68 for the left and right rear wheels is connected between the regulator pressure supply conduit 53 and the left and right rear wheel control valves 28, and the control valves 28 are respectively brake oil pressure control conduits for the rear wheels. 26 and on-off valve 60RL, 60RR
, And the first position shown in the drawing for interrupting the communication between the on-off valves 60RL, 60RR and the regulator pressure supply conduit 68, the brake hydraulic control conduit 26 and the on-off valves 60RL, 60RR.
And the switching to the second position where the on-off valves 60RL, 60RR and the regulator pressure supply conduit 68 are connected.

The control valves 50FL, 50FR, and 28 function as master cylinder pressure shut-off valves, and when these control valves are at the first positions shown in the drawings, the wheel cylinders 48FL, 48FR, 48FR
FR, 64RL, 64RR are connected in communication with conduits 18, 26,
By supplying the master cylinder pressure to each wheel cylinder, the braking force of each wheel is controlled according to the amount of depression of the brake pedal 12 by the driver, and the control valves 50FL, 50FL
When 0FR, 28 is in the second position, each wheel cylinder is shut off from the master cylinder pressure.

The switching valves 42 and 44 switch the hydraulic pressure supplied to the wheel cylinders 48FL, 48FR, 64RL and 64RR between the accumulator pressure and the regulator pressure, and the control valves 50FL, 50FR and 28 control the hydraulic pressure. Is switched to the second position and the on-off valves 54FL, 54FR, 60RL, 60
When the switching valves 42 and 44 are maintained at the illustrated first positions while the RR and the on-off valves 56FL, 56FR, 62RL, and 62RR are at the illustrated positions, the wheel cylinder 48FL,
By supplying the regulator pressure to the 48FR, 64RL, and 64RR, the pressure in each wheel cylinder is controlled by the regulator pressure, whereby the braking of that wheel is performed regardless of the amount of depression of the brake pedal 12 and the braking pressure of the other wheels. The pressure is controlled in a pressure increase mode by a regulator pressure.

Even if each valve is switched to the pressure increasing mode by the regulator pressure, when the pressure in the wheel cylinder is higher than the regulator pressure, the oil in the wheel cylinder flows backward, and the control mode is the pressure increasing mode. Nevertheless, the actual braking pressure decreases.

The control valves 50FL, 50FR, 28 are switched to the second position, and the on-off valves 54FL, 54FR, 60RL,
When the switching valves 42 and 44 are switched to the second position with the 60RR and the opening / closing valves 56FL, 56FR, 62RL, and 62RR in the illustrated positions, the wheel cylinders 48FL, 48F
By supplying the accumulator pressure to R, 64RL, and 64RR, the pressure in each wheel cylinder is controlled at an accumulator pressure higher than the regulator pressure, thereby affecting the amount of depression of the brake pedal 12 and the braking pressure of other wheels. Instead, the braking pressure of the wheel is controlled in the pressure increasing mode by the accumulator pressure.

Further, with the control valves 50FL, 50FR, 28 switched to the second position, the on-off valves 54FL, 54FR, 6
0RL and 60RR are switched to the second position, and the on-off valve 56F
When L, 56FR, 62RL, and 62RR are controlled to the state shown in the figure, the pressure in each wheel cylinder is maintained regardless of the positions of the switching valves 42 and 44, and the control valves 50FL, 50FR, 28
Are switched to the second position and the on-off valves 54FL, 5FL
4FR, 60RL, 60RR and open / close valve 56FL, 56FR, 62
When RL and 62RR are switched to the second position, the switching valve 42
The pressure in each wheel cylinder is reduced irrespective of the positions of and 44, whereby the braking pressure of the wheel is controlled in the reduced pressure mode regardless of the amount of depression of the brake pedal 12 and the braking pressure of the other wheels.

Switching valves 42 and 44, control valves 50FL, 50
FR, 28, on-off valves 54FL, 54FR, 60RL, 60RR and on-off valves 56FL, 56FR, 62RL, 62RR are controlled by an electric control device 70 as described later in detail. The electric control device 70 includes a microcomputer 72 and a drive circuit 74. The microcomputer 72 includes, for example, a central processing unit (CPU), a read-only memory (ROM), not shown in detail in FIG. , A random access memory (RAM), and an input / output port device, which may be connected to each other by a bidirectional common bus.

A signal indicating a vehicle speed V from a vehicle speed sensor 76, a signal indicating a lateral acceleration Gy of a vehicle body from a lateral acceleration sensor 78 provided substantially at the center of gravity of the vehicle body, a yaw rate sensor 80 A signal indicating the yaw rate γ of the vehicle body, a signal indicating the steering angle θ from the steering angle sensor 82, a signal indicating the longitudinal acceleration Gx of the vehicle body from a longitudinal acceleration sensor 84 provided substantially at the center of gravity of the vehicle body, the wheel speed sensors 86FL From 86RR, the wheel speeds (peripheral speeds) VFL, VFR, VRL, V
A signal indicating RR and a signal indicating whether or not the switch is on from the brake switch 88 are input. The lateral acceleration sensor 78 and the like detect lateral acceleration and the like with the left turning direction of the vehicle as positive.

The ROM of the microcomputer 72 stores various control flows and maps as described later, and the CPU performs various calculations as described later on the basis of the parameters detected by the various sensors described above. The spin value SV for determining the turning behavior is obtained, the turning behavior of the vehicle is estimated and controlled based on the spin value, and the ABS control is performed on the braking force of each wheel.

Next, the turning behavior control of the vehicle (hereinafter referred to as "VSC") will be described with reference to the flowcharts shown in FIGS.
) And the control amount calculation routine of the ABS control will be described. The control according to the flowcharts shown in FIGS. 2 and 3 and the control according to the flowchart shown in FIG. 4 are started by closing an ignition switch (not shown), and are repeatedly executed at predetermined time intervals.

First, in step 10 of the VSC control amount calculation routine shown in FIG. 2, a signal indicating the vehicle speed V detected by the vehicle speed sensor 56 is read, and in step 20, the lateral acceleration Gy is read. The deviation of the lateral acceleration as the deviation Gy-V * γ between the product and the product V * γ of the vehicle speed V and the yaw rate γ,
That is, the side slip acceleration Vyd of the vehicle is calculated, and step 3
At 0, the lateral slip velocity Vy of the vehicle body is calculated by integrating the deviation Vyd of the lateral acceleration. In step 40, the slip angle β of the vehicle body is calculated as a ratio Vy / Vx of the vehicle body slip speed Vy to the vehicle longitudinal speed Vx (= vehicle speed V). In step 50, A and B are positive constants. Based on the lateral acceleration deviation Vyd calculated in step 20 and the vehicle body slip angle β calculated in step 40, the spin value SV is calculated according to the following equation 1.
Is calculated.

[Equation 1] SV = A * Vyd + B * β

The calculation itself of the spin value SV does not constitute the gist of the present invention, and the spin value may be obtained in any manner as long as it is calculated as a state quantity corresponding to the spin state of the vehicle. Slip angle β
And a linear sum of the vehicle body slip angular velocity βd.

In step 60, when the spin value SV is positive, the control wheel, that is, the wheel whose braking force is to be controlled in accordance with the spin value is specified as the outer wheel on the front wheel side. When the value is negative, the left front wheel is specified. In step 70, the basic target slip ratio Rsb of the left front wheel or the right front wheel is calculated from the map corresponding to the graph shown in FIG. 5 based on the absolute value of the spin value SV.

In step 80, it is determined whether or not braking is being performed, that is, whether or not the brake switch 88 is on. If the determination is affirmative, the process proceeds to step 110; When the determination is made, it is determined in step 90 whether or not the turning behavior control is being performed. If an affirmative determination is made in step 90, the actual slip ratio S of the turning outer wheel is calculated in step 100 according to the following equation 2 with the wheel speeds of the turning outer wheel and the turning inner wheel on the front wheel side as Vout and Vin, respectively. The ratio of the absolute value of the longitudinal acceleration Gx to the actual slip ratio S | Gx | / S
The correction coefficient K1 for the basic target slip ratio Rsb is calculated from the map corresponding to the graph shown in FIG. 6 based on this ratio. If a negative determination is made, the correction coefficient K1 is determined in step 110. Set to 1.

S = (Vout−Vin) / Vin

In step 120, the vehicle turns according to the following equation 3 based on the slip angle β of the vehicle body, the yaw rate γ of the vehicle body, the vehicle speed V calculated in step 40, and the steering angle θ detected by the steering angle sensor 82. The slip angle α of the outer wheel is calculated, and the correction coefficient K2 is calculated from a map corresponding to the graph shown in FIG. In equation (3), Lf is the distance between the center of gravity of the vehicle and the axle of the front wheel, and Nf
Is the steering gear ratio.

Α = β + Lf * γ / V−θ / N

In step 130, the lateral acceleration sensor 7
8, a load shift amount .DELTA.Wf in the lateral direction of the vehicle on the front wheel side is calculated based on the lateral acceleration Gy of the vehicle body detected by step 8, and when the standard loads of the front outer wheel and the inner wheel are Wouto and Wino, respectively, The correction coefficient K3 is calculated as the reciprocal Win / Wout of the ratio of the load on the turning outer wheel to the load on the turning inner wheel according to the following equation (4). Step 1
In step 40, the target slip ratio Rs is calculated as the product of the correction coefficients K1 to K3 and the basic target slip ratio Rsb.

K3 = Win / Wout = (Wino−ΔWf) / (Wouto + ΔWf)

In step 150, it is determined whether or not the turning behavior control is being performed. If the determination is affirmative, in step 160, the longitudinal acceleration of the vehicle body is determined as a state quantity representing the friction coefficient μ of the road surface. The vector sum (Gx ² + Gy ² ) ^{1/2 of} Gx and the lateral acceleration Gy is calculated, and the upper limit value Rsmax of the target slip ratio is calculated from the map corresponding to the graph shown in FIG. 8 based on the vector sum. , When a negative determination is made, the upper limit value Rsmax of the target slip ratio
Is set to the default value Rsmaxb.

In step 180, AB set by an ABS control amount calculation routine shown in FIG.
Based on the S request flag, it is determined whether or not the front turning inner wheel is under ABS control. If a negative determination is made, the process directly proceeds to step 200, and if a positive determination is made, the process proceeds to step 190. Thus, the upper limit value Rsmax of the target slip ratio is corrected to be reduced by a predetermined value ΔRso (positive constant). In step 200, it is determined whether or not the target slip ratio Rs calculated in step 140 exceeds the upper limit value Rsmax. If a negative determination is made, the process directly proceeds to step 220, and an affirmative determination is made. Is performed, in step 210, the target slip ratio Rs is set to the upper limit value Rsmax.

In step 220, the target wheel speed Vwt of the front turning side outer wheel is calculated according to the following equation 5 with Vin as the wheel speed of the front turning side inner wheel.

Vwt = (1-Rs) * Vin

In step 230, the duty ratios Dr of the drive current for the open / close valve of the front turning outer wheel are Kp and Kd, respectively, as the proportional constants of the proportional term and the differential term in the wheel speed feedback control. In step 240, the VSC request flag is set according to the duty ratio Dr.

## EQU6 ## Dr = Kp * (Vout-Vwt) + Kd * d (V
out-Vwt) / dt

In this case, the duty ratio is a positive constant Dop
Is exceeded, the braking pressure control mode is set to the pressure increasing mode, and when the duty ratio Dr is less than the negative constant Don, the braking pressure control mode is set to the pressure reducing mode, and the duty ratio is equal to or more than Don and equal to or less than Dop. , The braking pressure control mode is set to the holding mode.

In step 250, it is determined whether or not braking is being performed. If a negative determination is made, the process returns to step 10; if an affirmative determination is made, the turning behavior control is performed in step 260. It is determined whether or not it is in the middle. When a negative determination is made in step 260, the process returns to step 10 as it is, and when an affirmative determination is made, in step 270, V is set so that the braking pressure for the front inner wheel is maintained at predetermined intervals for a predetermined period of time.
The SC request flag is updated.

In step 310 of the ABS control amount calculation routine shown in FIG. 4, a signal indicating the vehicle speed V detected by the vehicle speed sensor 76 and the wheel speed sensors 86FL to 86FL are output.
A signal indicating the wheel speeds Vi (i = FL, FR, RL, RR) of the left and right front wheels and the left and right rear wheels detected by 86RR is read. In step 320, Ks is set as a positive constant and 7, the slip amount Si of each wheel is calculated.

## EQU7 ## Si = V-Ks * Vi

In step 330, when the slip amount Si is less than the negative constant Son, the duty ratio Dra is calculated according to the slip amount, the braking pressure control mode is determined to be the pressure increasing mode, and the slip amount Si is determined. Positive constant Sop
Is exceeded, the duty ratio Dra is calculated in accordance with the slip amount, the braking pressure control mode is determined to be the pressure reduction mode, and the slip amount Si is equal to or greater than Son and Sop
If not, the duty ratio Dra is set to 0%, and the braking pressure control mode is determined to be the holding mode. In step 340, the duty ratio Dra is calculated based on the duty ratio Dra and the braking pressure control mode calculated in step 330. The ABS request flag is set as described later.

The calculation of the ABS control amount does not constitute the gist of the present invention, is not limited to the routine shown in FIG. 4, and may be performed in any conventionally known manner.

As shown in FIGS. 9A and 9B, the VSC request flag and the ABS request flag are
Parts for indicating the positions of 2 and 44 and control valves 50FL, 5FL
0FR, a part for indicating the position of 28, and on-off valves 54FL, 5FL
4FR, 60RL, 60RR and open / close valve 56FL, 56FR, 62
RL and 62RR indicate the position. In particular, in the VSC request flag, the switching valve 42 is instructed to the second position, the control valve 50FL or 50FR is instructed to the second position, and the on-off valves 54FL and 56FL or the on-off valve 54FR and 56FR is indicated in the first or second position. Also, in the ABS request flag, the switching valve 42 or 44 is instructed to the first position, and the control valves 50FL, 50
0FL or 28 is instructed to the second position, and the on-off valves 54FL, 54FR, 60RL, 60RR and the on-off valves 56FL, 56FR, 62RL, 62RR are instructed to the first or second position according to the control mode.

Next, a valve drive processing routine in the first embodiment will be described with reference to a flowchart shown in FIG. The control according to the flowchart shown in FIG. 10 is also started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.

In step 410, it is determined whether the VSC is in progress and the ABS control is being performed based on the VSC request flag and the ABS request flag. If a negative determination is made, the ABS control is performed in step 420. It is determined whether or not it is in the middle. When an affirmative determination is made in step 420, an output flag (FIG.
(C), the ABS request flag is set as it is. After completion of step 430 or when a negative determination is made in step 420, a determination is made in step 440 as to whether or not VSC is being performed, and when an affirmative determination is made, an output is made in step 450. VSC for flag
The request flag is set as it is.

In step 460, mask processing of the VSC request flag is performed, and in step 470, ABS processing is performed.
The request flag is masked, and in step 480, the output flag is set to the superposition of the VSC request flag and the ABS request flag. In the masking process of the VSC request flag executed in step 460, V
For each valve associated with the wheel on which the SC is executed, the VSC indication is stored and the other indications are cleared, step 47
In the process of masking the ABS request flag executed at 0, the ABS control instruction is stored for the valve associated with the wheel on which VSC is not executed, and the other instructions are cleared. In the superposition of the two flags executed in step 480, the instruction of the two flags is superimposed by storing the instruction of the other flag in the cleared portion of one flag. .

In step 490, it is determined whether or not the VSC request flag is pressure increase. If an affirmative determination is made, in step 500, it is determined whether or not the ABS request flag is pressure increase. A determination is made. If a negative determination is made in step 500, the process proceeds to step 550 as it is.
When the determination is affirmative, the holding output is set to the ABS control wheel of the output flag in step 510, and the switching valve 42 or 44 of the output flag is set to the second position in step 520. .

If a negative determination is made in step 490, it is determined in step 530 whether or not the ABS request flag is a pressure increase. If a negative determination is made, the process proceeds directly to step 550, If an affirmative determination is made, at step 540 the output flag switching valve 4
2 or 44 is set to the first position. Step 55
At 0, a control signal corresponding to the output flag is output to a switching valve or the like.

For example, FIGS. 9D and 9E show masked VSs when VSC is applied to the right front wheel, respectively.
The C request flag and the masked ABS request flag are shown.

Thus, in this embodiment, step 2
Spin value S indicating the turning behavior of the vehicle at 0 to 50
V is calculated, and in step 60, the control wheel, that is, the turning outer wheel on the front wheel side is specified according to the sign of the spin value SV as a wheel to which a braking force is to be applied to suppress spin and drift out of the vehicle, Steps 70-210
In step 220, the target slip rate Rs of the control wheel is calculated, and in step 220, the target wheel speed Vwt according to the target slip rate is calculated.
Is calculated at step 230, and a duty ratio Dr for feedback control of the wheel speed of the control wheel is calculated at step 230. At step 240, V is calculated according to the duty ratio Dr.
The SC request flag is set.

In particular, steps 80 to 110 and step 140 of the flow chart shown in FIG. 2 of this embodiment correspond to a part of the structure of claim 1, and in step 80 it is determined that braking is being performed. Is performed, and it is determined in step 90 that the turning behavior is being controlled. In step 100, the actual slip ratio S of the turning outer wheel is calculated, and the absolute value of the longitudinal acceleration Gx with respect to the actual slip ratio S is calculated. Ratio | G
x | / S is calculated, and a correction coefficient K1 for the basic target slip rate Rsb is calculated from the map corresponding to the graph shown in FIG. 6 based on this ratio. It is corrected by K1.

In this case, the ratio | Gx | / S calculated in step 100 is μ-S between the road surface and the turning outer wheel.
Which corresponds to the slope of the linear region of the characteristic,
Is calculated such that the larger the slope of the linear region of the μ-S characteristic is, the smaller the target slip ratio Rs becomes, so that the surface properties of the road surface change with the running of the vehicle and changes in the weather. Even in the case where the inclination of the linear region of the S characteristic changes, the braking force of the turning outer wheel on the front wheel side is accurately controlled to a value necessary for stabilizing the turning behavior, and regardless of the change in the surface texture of the road surface. An optimal anti-spin moment is generated.

Steps 120 and 14 of this embodiment
0 corresponds to a part of the configuration of claim 2, and step 1
At 20, the vehicle slip angle β, the vehicle yaw rate γ,
The slip angle α of the turning outer wheel is calculated based on the vehicle speed V and the steering angle θ, the correction coefficient K2 is calculated from a map corresponding to the graph shown in FIG. 7, and in step 140, the basic target slip ratio Rsb is calculated. It is corrected by the correction coefficient K2.

Accordingly, the target slip ratio Rs is calculated according to the slip angle α of the turning outer wheel. As a result, the slope of the linear region is estimated for the μ-S characteristic corresponding to the slip angle α, and the slip of the turning outer wheel is calculated. Since the effect of changing the μ-S characteristics depending on the angle is eliminated, the braking force of the turning outer wheel is accurately adjusted to a value necessary for stabilizing the turning behavior regardless of the slip angle of the turning outer wheel during turning of the vehicle. The optimum anti-spin moment is generated regardless of the change in the slip angle.

Also, steps 130 and 14 of this embodiment
0 corresponds to a part of the configuration of the third aspect, and the reciprocal Win of the ratio of the load of the turning outer wheel to the load of the turning inner wheel based on the lateral acceleration Gy of the vehicle body detected by the lateral acceleration sensor 78.
A correction coefficient K3 based on the wheel load ratio is calculated as / Wout, and in step 140, the basic target slip ratio Rsb is corrected by the correction coefficient K3.

Accordingly, the target slip rate Rs is calculated to be smaller as the ratio (Wout / Win) of the load of the turning outer wheel ( control wheel) to the load of the turning inner wheel (wheel as a reference for the slip rate calculation) becomes higher. Regardless of the change in the load of the turning outer wheel and the turning inner wheel caused by the load movement accompanying the turning and braking of the vehicle, the braking force of those wheels is accurately controlled to a value necessary to stabilize the turning behavior, The actually generated anti-spin moment is precisely controlled.

Steps 150 to 170 of this embodiment
Steps 200 and 210 correspond to a part of the configuration of claim 4. If it is determined in step 150 that the turning behavior is being controlled, then in step 160, the friction coefficient μ of the road surface is reduced. The longitudinal acceleration Gx of the vehicle
And the vector sum of the lateral acceleration Gy (Gx ² + Gy ² ) ^1/2
Is calculated, and the upper limit value Rsmax of the target slip ratio is calculated from the map corresponding to the graph shown in FIG. 8 based on the vector sum. In step 200, it is determined whether or not the target slip ratio Rs exceeds the upper limit value Rsmax. When an affirmative determination is made, the target slip ratio Rs is set to the upper limit value Rsmax in step 210. You.

Therefore, the lower the road surface friction coefficient, the larger the upper limit value Rsmax of the target slip ratio is set, and the higher the target slip ratio Rs is allowed, the higher the target slip ratio Rs becomes. Generation of an effective anti-spin moment ensures that the turning behavior of the vehicle is well controlled, and the turning gradient of the turning outer wheel is increased due to the large negative gradient in the region above the peak value of the μ-S characteristic. Hunting is also reliably prevented in the control of the braking pressure, and when the road surface friction coefficient is low, the target slip ratio is set to a high value as necessary,
The unstable turning behavior of the vehicle is reliably stabilized.

Steps 180 to 210 of this embodiment
Corresponds to a part of the configuration of claim 5, and step 18
At 0, it is determined whether or not the inner turning wheel on the front wheel side is under ABS control. If an affirmative determination is made, at step 190, the upper limit value Rsmax of the target slip ratio is increased to a predetermined value Δ.
Rso (positive constant) is reduced and corrected. Step 200
It is determined whether or not the target slip rate Rs exceeds the upper limit value Rsmax. If the determination is affirmative, the target slip rate Rs is set to the upper limit value R in step 210.
Set to smax.

[0071] When the turning inner front wheel as a reference of the slip rate calculating is ABS control, therefore, i.e. the front wheels
When the actual slip rate of the turning inner wheel on the side is high, the upper limit value Rsmax of the target slip rate is set to a small value and the target slip rate Rs is prevented from becoming a high value. Prevention of generation of an appropriate anti-spin moment due to the existence of a certain value, and hunting of control of the braking pressure of the turning outer wheel due to a negative gradient in a region equal to or higher than the peak value of the μ-S characteristic are also prevented. .

In this embodiment, steps 250 to 270 are performed.
Corresponds to a part of the structure of claim 6 and corresponds to step 25.
At 0, it is determined whether or not braking is being performed, and when an affirmative determination is made, at step 260, it is determined whether or not turning behavior control is being performed, and an affirmative determination is made. In some cases, at step 270, the VSC request flag is updated so that the braking pressure of the front inner wheel is maintained for a predetermined time at predetermined time intervals.

[0073] Thus the operation of sudden braking is performed by the driver, when there is a possibility that the braking pressure of the turning inner front wheel is the reference wheel is pressurized rapidly by the master cylinder pressure, before
Since the braking pressure of the inner turning wheel on the front wheel side is adjusted so that the increasing pressure gradient of the braking pressure of the inner turning wheel on the wheel side becomes smaller than the increasing pressure gradient of the braking pressure on the outer turning wheel , the driver performs sharp braking operation. Even if it does, the pressure increase gradient of the braking pressure of the turning outer wheel always becomes larger than the pressure increasing gradient of the braking pressure of the turning inner wheel, whereby the anti-spin moment necessary for stabilizing the turning behavior is surely generated.

For example, FIGS. 11 and 12 show an example of changes in the braking pressure of the front outer wheel and the inner wheel when the slow braking and the rapid braking are performed by the conventional behavior control device, respectively. FIG. 13 shows an example of a change in the braking pressure of the outer turning wheel and the inner turning wheel on the front wheel side when sudden braking is performed in the illustrated embodiment.

As shown in FIG. 11, even in the case of the conventional behavior control device, the braking operation by the driver is gentle, and the gradient of increasing the braking pressure of the turning inner wheel increased by the master cylinder pressure is also gentle. When the VSC is started, the braking pressure increase gradient of the turning outer wheel, which is increased by the accumulator pressure when the VSC is started, is larger than the braking pressure increasing gradient of the turning inner wheel, whereby the braking force of the turning outer wheel turns. An anti-spin moment is generated by being higher than the braking force of the inner wheel.

However, as shown in FIG. 12, when the braking operation by the driver is very sharp and the gradient of the increase in the braking pressure of the turning inner wheel is also very sharp, VSC is started and the braking of the turning outer wheel is started. Even if the pressure is increased by the accumulator pressure, the increasing gradient of the braking pressure of the turning outer wheel becomes substantially the same as the increasing gradient of the braking pressure of the inner turning wheel, and no anti-spin moment is generated. As a result, the braking force of the turning outer wheel is lower than the braking force of the turning inner wheel, and a moment in the opposite direction to the anti-spin moment, that is, in the direction opposite to the direction stabilizing the turning behavior of the vehicle is generated. Therefore, the turning behavior may be rather deteriorated by the VSC.

On the other hand, according to the embodiment shown in FIG.
As shown in, even if the driver performs a sudden braking operation, the increasing gradient of the braking pressure of the turning outer wheel always becomes larger than the increasing gradient of the braking pressure of the turning inner wheel, and the braking force of the turning outer wheel is increased. When the braking force is always higher than the braking force of the turning inner wheel, an effective anti-spin moment is generated, whereby the turning behavior is reliably stabilized.

In the illustrated embodiment, the present invention is applied to an ABS.
The present invention is applied to a mounted vehicle, and steps 180 and 190 are executed in correspondence with claim 5 described above.
In the braking device to which the present invention is applied, the hydraulic pressure supplied to each wheel cylinder is controlled by the hydraulic pressure from the master cylinder 14 or the accumulator 46.
The braking device may be only the hydraulic pressure stored in the brake device.

Further, in the embodiment shown in FIG.
In step 26, it is determined that braking is in progress.
When it is determined at 0 that the turning behavior control is being performed, the VSC request flag is updated in step 270 such that the braking pressure for the reference wheel is maintained for a predetermined time at predetermined time intervals. However, in this step, the VSC request flag may be updated so that the duty ratio of the control wheel is increased and corrected, or the braking pressure of the reference wheel is held for a predetermined time at predetermined time intervals and the control wheel The VSC request flag may be updated so that the duty ratio is corrected to increase.

Step 270 in the illustrated embodiment.
In this case, the predetermined time during which the braking pressure of the reference wheel is held is constant, but the predetermined time or the rate of increase of the duty ratio of the control wheel is such that the larger the value of the spin value SV, the larger the spin value. May be variably set in accordance with.

Step 250 in the illustrated embodiment.
In this case, it is determined whether or not braking is being performed. However, when the brake switch 88 is turned on, a sudden braking state is determined based on the deceleration of the wheels other than the control wheels and the rate of change of the longitudinal acceleration Gx. Is determined, and only when rapid braking is being performed and turning behavior control is being performed, in step 270, the pressure increase gradient of the control wheel is increased by the pressure increase gradient of the reference wheel. It may be configured to perform processing to make the height higher. According to this configuration, when the braking operation by the driver is gentle, the gradient of increasing the braking pressure of the reference wheel is not unnecessarily reduced, and the braking pressure of the control wheel is not unnecessarily increased.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments may be included within the scope of the present invention. It will be clear to those skilled in the art that is possible.

For example, in the above-described embodiment, when the vehicle spins, the braking force of the front turning outer wheel is controlled according to the spin value SV, and the braking force of the front turning outer wheel and the turning inner wheel are controlled. Although the spin is reduced by the anti-spin moment due to the difference with the braking force,
The braking force of the outer turning wheels on both the front wheel side and the rear wheel side may be controlled.

In the above-described embodiment, when the VSC pressure increase request for the front turning outer wheel and the ABS control pressure increase request for the front turning inner wheel conflict with each other, V
Although the SC request is given priority, the request for ABS control may be given priority, or the request generated earlier may be given priority.

[0085]

As is apparent from the above description, according to the first aspect of the present invention, the inclination of the linear region of the μ-S characteristic between the road surface and the turning outer wheel is determined by the inclination estimating means. Since the target slip ratio is corrected by the target slip ratio correction means so as to become smaller as the inclination of the estimated linear region becomes larger, the surface property of the road surface changes as the vehicle travels. Even if the inclination of the linear region changes, the braking force of the turning outer wheel is accurately controlled to the value required to stabilize the turning behavior, and the optimal anti-spin moment is generated regardless of the change in the surface texture of the road surface, Thereby, the turning behavior of the vehicle can be controlled well.

According to the second aspect of the present invention, the inclination estimating means is configured to estimate the inclination of the linear region with respect to the μ-S characteristic corresponding to the slip angle of the turning outer wheel. According to the slip angle of the turning outer wheel, the braking force of the wheel is precisely controlled to a value necessary to stabilize the turning behavior, and an optimum anti-spin moment is generated regardless of the change in the slip angle of the turning outer wheel , Thereby, the turning behavior of the vehicle can be favorably controlled.

According to the third aspect of the present invention, the ratio of the load of the turning outer wheel to the load of the wheel, which is the reference of the slip ratio calculation, is detected, and the higher the load ratio, the smaller the target slip ratio. because it is corrected by the correction means, handed due to accompanying load shift to the turning and the braking of the vehicle
Regardless of the change in the load of the wheel, which is the basis of the calculation of the outer wheel and the slip ratio, the braking force of those wheels is accurately controlled to the value necessary to stabilize the turning behavior, and the anti-spin moment actually generated is calculated. It is possible to control the vehicle accurately and thereby control the turning behavior of the vehicle satisfactorily.

According to the structure of the fourth aspect, the coefficient of friction of the road surface is detected, and the upper limit of the target slip ratio is set so as to increase as the friction coefficient of the road surface decreases. The turning behavior of the vehicle can be satisfactorily controlled by generating an effective anti-spin moment without hindrance, and braking of the turning outer wheel due to a large negative gradient in the region above the peak value of the μ-S characteristic It is possible to reliably prevent hunting from occurring in the control of the pressure, and when the coefficient of friction of the road surface is low , the target slip ratio of the turning outer wheel can be set to a high value as required, so that sufficient By generating a spin moment, the turning behavior of the vehicle can be reliably controlled.

According to the fifth aspect of the present invention, it is detected whether or not the front turning inner wheel , which is a reference for calculating the target slip ratio, is controlled by the ABS device, and the front turning inner wheel is controlled by the ABS device. Outside turning when controlled
Since the upper limit of the target slip ratio of the wheel is set small,
An appropriate anti-spin moment can be prevented from being not generated due to an excessive slip ratio, and the braking pressure of the turning outer wheel due to a negative gradient in a region equal to or higher than the peak value of the μ-S characteristic can be prevented. Hunting of the control can be prevented.

Further, according to the configuration of claim 6, the braking operation by the driver is detected, and when the braking operation is performed by the driver, the braking pressure is controlled to increase the braking pressure of the wheels other than the turning outer wheel. since slope braking pressure of the wheel other than the revolving outer or revolving outer ring to be smaller than the pressure increase gradient of the braking pressure of the revolving outer ring is adjusted, even if a sudden braking operation is performed by the driver, the braking can pressure is greater than the pressure increase gradient of the braking pressure of the wheel other than the always orbiting outer ring of the pressure increase gradient of the braking pressure of the turning outer wheel to be controlled, thereby anti-spin necessary to stabilize the turning behavior The turning behavior can be reliably stabilized by reliably generating a moment. Further, according to the configuration of claim 7 described above, the road surface and
The coefficient of friction of the road surface between the turning outer wheel and the friction coefficient is estimated.
Means, and the estimated friction coefficient of the road surface is large.
Target slip rate so that it becomes smaller
Since the correction is performed by the correction means, the configuration according to claim 1 described above.
As in the case of, the surface properties of the road surface change with traveling,
As a result, even if the friction coefficient of the road surface changes,
Precise control of power to the value required to stabilize turning behavior
And optimal anti-spin regardless of changes in road surface properties
A moment to improve the turning behavior of the vehicle.
It can be controlled well. Further, the above-mentioned configuration of claim 8
According to the configuration of claim 7, the friction coefficient estimating means is
Estimating the friction coefficient of the road surface considering the slip angle of the turning outer wheel
The configuration of claim 2
As in the case, slip of the turning outer wheel during turning of the vehicle
Stabilizes turning behavior by braking force of the wheel according to the angle
Control to the value required for
Generate the optimal anti-spin moment regardless of the
This makes it possible to better control the turning behavior of the vehicle
You.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a vehicle braking device to which a behavior control device according to the present invention is applied and an electric control device thereof.

FIG. 2 is a flowchart showing a part of a VSC control amount calculation routine of the behavior control device according to the present invention.

FIG. 3 is a flowchart showing the remaining part of the VSC control amount calculation routine of the behavior control device according to the present invention.

FIG. 4 is a flowchart showing an ABS control amount calculation routine of the behavior control device according to the present invention.

FIG. 5 is a graph showing a relationship between an absolute value of a spin value SV and a basic target slip ratio Rsb.

FIG. 6 is a graph showing the relationship between the ratio of the absolute value of the longitudinal acceleration Gx to the actual slip ratio S and the correction coefficient K1.

FIG. 7 is a graph showing a relationship between a wheel slip angle α and a correction coefficient K2.

FIG. 8 is a graph showing a relationship between a vector sum of a longitudinal acceleration Gx and a lateral acceleration Gy and an upper limit value Rsmax of a target slip ratio.

FIG. 9 is an explanatory diagram showing a VSC request flag, an ABS request flag, and an output flag.

FIG. 10 is a flowchart showing a valve drive processing routine according to an embodiment of the behavior control device according to the present invention.

FIG. 11 is a time chart showing an example of a change in braking pressure of a front outer wheel and a turning inner wheel at the time of gentle braking in the case of a conventional behavior control device.

FIG. 12 is a time chart showing an example of a change in the braking pressure of the outer turning wheel and the inner turning wheel on the front wheel side at the time of sudden braking in the case of a conventional behavior control device.

FIG. 13 is a time chart showing an example of a change in the braking pressure of the outer turning wheel and the inner turning wheel on the front wheel side at the time of sudden braking in the case of the illustrated embodiment.

FIG. 14 is a graph showing μ-S characteristics between a road surface and wheels with respect to a friction coefficient μ of various road surfaces.

FIG. 15 is a graph showing the relationship between the slip ratio S and the braking force F of the wheels for various road surface friction coefficients μ.

FIG. 16 is a graph showing μ-S characteristics between a road surface and wheels for various wheel slip angles α.

[Explanation of symbols]

 Reference Signs List 10 brake device 14 master cylinder 16 hydro booster 20, 22, 32, 34 brake hydraulic control device 28, 50FL, 50FR control valve 42, 44 switching valve 44FL, 44FR, 64RL, 64RR wheel cylinder 54FL 54FR, 60RL, 60RR: On-off valve 56FL, 56FR, 62RL, 62RR: On-off valve 72: Electric control device 76: Vehicle speed sensor 78: Lateral acceleration sensor 80: Yaw rate sensor 86FL-86RR: Wheel speed sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60T 8/00-8/96

Claims (8)

(57) [Claims] The present invention relates to a behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle, and to correspond to a braking force of a turning outer wheel necessary for stabilizing the turning behavior according to the spin state quantity. It calculates a target slip ratio, the turning outer
Wherein handed so that the slip ratio of the wheels becomes the target slip ratio
The behavior control device of a vehicle and a behavior control means for controlling the braking pressure of Kaigairin Te at a slope estimating means for estimating the slope of the linear region of at mu-S characteristic between the turning outer wheel and the road surface And a target slip ratio correcting means for correcting the target slip ratio so as to decrease as the estimated inclination of the linear region increases. 2. The vehicle behavior control device according to claim 1, wherein said inclination estimating means includes a μ according to a slip angle of said turning outer wheel.
A vehicle behavior control device configured to estimate a slope of a linear region with respect to an S characteristic. 3. A behavior estimating means for estimating a spin state on the basis of a spin state quantity indicating a turning behavior of a vehicle, and corresponding to a braking force of a turning outer wheel necessary for stabilizing the turning behavior according to the spin state quantity. It calculates a target slip ratio, the turning outer
Wherein handed so that the slip ratio of the wheels becomes the target slip ratio
In a vehicle behavior control device having behavior control means for controlling a braking pressure of a turning outer wheel, a means for detecting a ratio of a load of the turning outer wheel to a load of a wheel serving as a reference of a slip ratio calculation, and And a target slip ratio correcting means for correcting the target slip ratio so that the target slip ratio decreases as the ratio increases. 4. A behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle, and a behavior estimating means corresponding to a braking force of a turning outer wheel necessary for stabilizing the turning behavior according to the spin state quantity. It calculates a target slip ratio, the slip ratio of the turning outer wheel at a behavior control device of a vehicle and a behavior control means for controlling the braking pressure of the turning outer so as to be the target slip ratio, the friction coefficient of the road surface A vehicle behavior control device comprising: means for detecting; and means for setting an upper limit value of the target slip ratio so as to increase as the friction coefficient of the road surface decreases. 5. A behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle on which an ABS device is mounted, and a turning outer wheel necessary for stabilizing the turning behavior according to the spin state quantity. Te at the target slip rate corresponding to the braking force is calculated, the behavior control device of a vehicle and a behavior control means the slip ratio of the turning outer wheel to control the braking pressure of the turning outer so as to be the target slip ratio Means for detecting whether or not the front inner wheel on the front wheel, which is a reference for calculating the target slip ratio, is controlled by the ABS device; and detecting the target slip ratio when the inner wheel is controlled by the ABS device. Means for setting the upper limit to a small value. 6. A behavior estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle, and a behavior control means for controlling a braking pressure of a turning outer wheel in accordance with the spin state quantity to stabilize the turning behavior. Means for detecting a braking operation by a driver, and increasing a braking pressure of wheels other than the turning outer wheel when the driver performs a braking operation. behavior control of the vehicle which gradient is characterized by having a means for adjusting the wheel brake pressure other than the turning outer wheel or the turning wheel to be smaller than the pressure increase gradient of the braking pressure of the turning outer wheel apparatus. 7. Based on the spin state quantity indicating the turning behavior of the vehicle
A behavior estimating means for estimating a spin state;
Required to stabilize the turning behavior according to the state parameters.
The target slip ratio corresponding to the braking force is calculated, and
Turn the wheel so that the slip rate of the wheel becomes the target slip rate.
Vehicle having behavior control means for controlling braking pressure of outer wheel
In the behavior control device of
Coefficient estimation means for estimating the friction coefficient of the road surface
The larger the specified coefficient of friction of the road surface, the smaller the
The target slip rate correction means for correcting the target slip rate
Vehicle behavior control device characterized by having a step.
Place. Claim 8. In the vehicle behavior control device according to claim 7,
The friction coefficient estimating means considers the slip angle of the turning outer wheel.
And is configured to estimate the friction coefficient of the road surface
A behavior control device for a vehicle, comprising: