JP3291937B2 - 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, a braking force is automatically applied when the vehicle speed exceeds a tire grip limit vehicle speed. For example, there is a predetermined gap between the brake mechanism provided on each wheel, for example, between the brake rotor and the pad or between the pad and the caliper, when there is no braking, so that the brake oil amount-actual braking pressure characteristic of each brake mechanism is FIG.
2, there is a dead zone in which the actual braking pressure does not substantially increase even if the amount of brake oil increases, so that it is necessary and sufficient to control the turning behavior at the start of the behavior control. There is a problem that the braking pressure cannot be generated with good responsiveness.

If the gain of the behavior control is set high in order to solve such a problem, the target followability of the braking pressure control of the behavior control after the rapid pressure increase is ensured even if the rapid pressure increase at the start of the behavior control can be reliably performed. Is deteriorated, and it becomes difficult to control the braking pressure to an optimum value due to so-called overshoot. Therefore, there is a problem that the behavior control cannot be satisfactorily executed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the conventional behavior control apparatus, and a main object of the present invention is to provide a behavior control that effectively applies a braking pressure at the start of behavior control. The purpose of the present invention is to prevent the deterioration of the responsiveness at the time of starting the behavior control due to the presence of the dead zone in the brake mechanism, and to execute the behavior control satisfactorily by rapidly increasing the pressure to a value required for performing the control.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle. and behavior control means for performing a spin suppression control by controlling the braking pressure of each wheel brake mechanism according to the spin state quantity, the opening of the spin suppress control
In a vehicle behavior control device having a sudden pressure increasing means for rapidly increasing a braking pressure at the beginning, the sudden pressure increasing means detects a deceleration of a wheel at the start of the spin suppression control, and detects the detected wheel.
Increase the braking pressure until the deceleration exceeds the reference value
The brake mechanism behavior control device of a vehicle, wherein the benzalkonium the male surge braking pressure to a predetermined value necessary to perform a spin control with effective beyond the dead zone, or the fourth aspect, the That is, a behavior estimating means for estimating the turning behavior of the vehicle based on a parameter indicating the turning behavior of the vehicle, and when the estimated turning behavior of the vehicle is unstable, controlling the braking pressure of the brake mechanism for the front wheels according to the parameter. and behavior control means for executing the behavior control by the elevation
The behavior control device of a vehicle and a rapid increase means for pressurizing surge brake pressure at the start of the dynamic control Te at, if turning behavior of the estimated been vehicle is in the spin state when the turning behavior is a drift-out state It is achieved by the rapid increase means the vehicle behavior control device, characterized in that a surge圧度focus change means to increase the surge圧度case of braking pressure by compared to.

According to the present invention, in order to effectively achieve the above-mentioned main object, in the configuration of claim 1, the behavior control device further includes means for detecting a coefficient of friction of a road surface,
The abrupt pressure increasing means is configured to set the predetermined value larger as the friction coefficient of the road surface is higher (the configuration of claim 2), and in the configuration of claim 1 or 2, the behavior control means is configured to control the spin state. The braking pressure is controlled based on the slip ratio of the wheel according to the amount (claim 3).

According to the present invention, in order to effectively achieve the above-described main object, in the vehicle behavior control apparatus according to the present invention, the rapid pressure increasing means detects the deceleration of the wheel and detects the deceleration. Sa
The brake pressure until the deceleration of the broken wheel exceeds the reference value
By so doing, it is configured to rapidly increase the braking pressure to a predetermined value necessary for performing effective behavior control beyond the dead zone region of the brake mechanism, and the sudden pressure increase degree changing means is configured to The predetermined value is set to be larger when the turning behavior is in the spin state than in the case where the turning behavior is in the drift-out state.

[0010]

According to the first aspect of the present invention, the rapid pressure increasing means detects the deceleration of the wheel at the start of the spin suppression control and detects the deceleration.
The brake pressure until the deceleration of the released wheel exceeds the reference value
Than that push sharp increase the braking pressure to exceed the dead zone of the brake mechanism to a predetermined value necessary to perform a spin suppress control with effective by applying spin while setting the gain of the spin suppress control to an appropriate value The braking pressure at the start of the suppression control is reduced to the value required for effective spin suppression control
It is possible to rapidly increase the pressure without excess or deficiency , thereby improving the responsiveness at the start of the spin suppression control,
Also, it is possible to prevent the target followability of the braking pressure control of the spin suppression control after the sudden pressure increase due to the control gain being too high from being deteriorated. It is possible to perform well.

In general, when the friction coefficient of the road surface is high, the braking force required to suppress the spin can be generated by increasing the braking pressure. However, when the friction coefficient of the road surface is low, the braking force is increased even if the braking pressure is increased. Since it is not possible to generate a braking force necessary for suppressing the brake force, it is preferable that the degree of the sudden increase in the braking pressure at the start of the spin suppression control is also controlled in accordance with the friction coefficient of the road surface.

[0012] According to the configuration of the second aspect, the first aspect.
In the configuration of the above, the behavior control device further includes means for detecting a road surface friction coefficient, and the sudden pressure increasing means is configured to set the predetermined value to be larger as the road surface friction coefficient is higher. the coefficient of friction is set a predetermined value is large when high, over the braking pressure at the start of the spin suppress control until the required value to do spin suppression control with effective
The pressure can be rapidly increased without any shortage, and when the friction coefficient of the road surface is low, the predetermined value is set to be small, thereby preventing excessive sudden pressure increase, thereby reducing the braking pressure at the start of the spin suppression control. It is possible to rapidly increase the pressure to an optimum value according to the friction coefficient.

When the magnitude of the braking force necessary for the spin suppression control is controlled based on the slip ratio, the deviation between the target wheel speed at the beginning of the control and the actual wheel speed is large. Although the response of the behavior control may be delayed, according to the configuration of the third aspect, in the configuration of the first or second aspect, the behavior control means may control the braking pressure based on the slip ratio of the wheel according to the spin state amount. It is configured to control, over non until the value required braking pressure at the start of the spin suppress control by the configuration of claim 1 or 2 performs a spin suppress control with effective
Since the pressure surge surely without feet, due to the deviation of the controlled initial target wheel speed and the actual wheel speed is larger to reduce the possibility that delayed response of the spin suppress control, the spin suppress control by this Responsiveness at the start can be improved.

[0014]

According to the fourth aspect of the present invention, when the estimated turning behavior of the vehicle is in the spin state, the braking pressure is rapidly increased by the rapid pressure increasing means as compared with the case where the estimated turning behavior is in the drift-out state. since a surge圧度if changing means for increasing a degree, sufficient responsiveness levator dynamic control start time <br/> in prepared to the front wheels to lock when turning behavior of the vehicle is in a spin state It can be secured, that the turning behavior reliably prevents the front wheels to lock when a drift-out state, is Rikyo dynamic control by the this reliably prevented that promotes drift-out state Becomes possible.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the rapid pressure increasing means reduces the number of wheels at the start of the behavior control.
Speed is detected and the detected wheel deceleration exceeds the reference value
The braking pressure is rapidly increased to a predetermined value required for effective behavior control beyond the dead zone of the braking mechanism .
With the behavior control gain set to an appropriate value,
The braking pressure at the start of control is necessary for effective behavior control.
The pressure can be rapidly increased to the required value without excess or shortage.
It is possible to improve the response at the start of behavior control.
Yes, and sudden pressure increase due to too high control gain
Target followability of braking pressure control in later behavior control deteriorates
Behavior by controlling the braking pressure to the optimum value.
It is possible to execute the control satisfactorily, and the sudden pressure increase degree changing means sets the predetermined value to a predetermined value when the estimated turning behavior of the vehicle is in the spin state, as compared with the case where the turning behavior is in the drift-out state. Is set to be large, so that when the turning behavior of the vehicle is in the spin state, the degree of sudden increase of the braking pressure by the sudden pressure increasing means is surely larger than when the turning behavior is in the drift-out state. Therefore, the above-described operation and effect according to claim 4 can be reliably obtained.

[0017]

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

FIG. 1 is a schematic structural view 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 has a master cylinder 14 for pumping brake oil from first and second ports in response to a driver's depressing operation of a brake pedal 12, and a first port. Is connected to brake hydraulic control devices 18 and 20 for the front left and right wheels by a brake hydraulic control conduit 16 for the front wheels, and the second port is connected to the rear left and right wheels by a brake hydraulic control conduit 24 for the rear wheels having a proportional valve 22 in the middle. Hydraulic control device 2 for
6 and 28. Further, the braking device 10 pumps the brake oil stored in the reservoir 30 and supplies it to the high-pressure conduit 32 as high-pressure oil.
have. The high-pressure conduit 32 is connected to each of the brake hydraulic control devices 18, 20, 26, 28, and an accumulator 36 is connected in the middle thereof.

Each of the brake hydraulic control devices 18, 20, 2
6, 28 are wheel cylinders 38FL, 38FR, 38RL, 38RR for controlling the braking force on the corresponding wheels, respectively.
And a 3-port 2-position switching type electromagnetic control valve 40FL,
The normally open electromagnetic on-off valves 44FL, 44FR, 44RL, 44RR provided between the 40FR, 40RL, 40RR and the low pressure conduit 42 and the high pressure conduit 32 connected to the reservoir 30 and the normally closed electromagnetic valve On-off valves 46FL, 46FR, 46RL, 46
RR. On-off valves 44FL, 44FR, 4 respectively
4RL, 44RR and open / close valve 46FL, 46FR, 46RL, 46RR
High-pressure conduit 32 between the connection conduits 48FL, 48FR, 48
Control valve 40FL, 40FR, 40RL, 40 by RL, 48RR
Connected to RR.

The control valves 40FL and 40FR are respectively a brake hydraulic control conduit 16 for the front wheels and a wheel cylinder 38FL.
And 38FR and wheel cylinder 38FL
, 38FR and the connection conduits 48FL and 48FR, the first position shown in the figure, the brake hydraulic control conduit 16 and the wheel cylinders 38FL and 38FR, and the wheel cylinders 38FL and 38FR and the connection conduit 48FL.
, And a second position for communicating and connecting with the 48FR. Similarly, 40RL and 40RR are respectively a brake hydraulic control conduit 24 for the rear wheel and a wheel cylinder 3
8RL and 38RR, and wheel cylinder 3
8RL and 38RR and the first position shown to cut off the communication between the connecting conduits 48RL and 48RR, and the brake hydraulic control conduit 2
4 to cut off the communication between the wheel cylinders 38RL and 38RR and connect the wheel cylinders 38RL and 38RR to the connecting conduit 4.
The position is switched to a second position for communicating and connecting 8RL and 48RR.

When the control valves 40FL, 40FR, 40RL, 40RR are in the second position, the on-off valves 44FL, 44FR,
4RL, 44RR and open / close valve 46FL, 46FR, 46RL, 46
When RR is controlled to the state shown in FIG.
FL, 38FR, 38RL, 38RR are control valves 40FL, 40FR,
40RL, 40RR and connecting conduits 48FL, 48FR, 48RL,
The pressure in the wheel cylinder is increased by communicating with the high pressure conduit 32 through 48RR. Conversely, when the control valve is in the second position, the on-off valves 44FL, 44FR,
44RL, 44RR are closed and the on-off valves 46FL, 46FR, 46
When the valves RL and 46RR are opened, the wheel cylinder is connected to the low-pressure conduit 42 via the control valve and the connection conduit, so that the pressure in the wheel cylinder is reduced. Further, when the control valve is in the second position, the on-off valve 44FL,
4FR, 44RL, 44RR and open / close valve 46FL, 46FR, 46
When the valves RL and 46RR are closed, the wheel cylinder is disconnected from both the high-pressure conduit 32 and the low-pressure conduit 42, so that the pressure in the wheel cylinder is maintained.

Thus, the braking device 10 includes the control valve 40FL,
When the 40FR, 40RL, 40RR is in the first position, the wheel cylinders 38FL, 38FR, 38RL, 38RR generate a braking force according to the amount of depression of the brake pedal 12 by the driver, and the control valves 40FL, 40FR, 40RL, 40RR.
When any of RR is in the second position, the on-off valves 44FL, 44FR, 44RL, 44RR and on-off valves 46FL,
By controlling the opening and closing of the wheels 46FR, 46RL and 46RR, the braking force of the wheel can be controlled irrespective of the amount of depression of the brake pedal 12 and the braking force of the other wheels.

Control valves 40FL, 40FR, 40RL, 40RR,
On-off valves 44FL, 44FR, 44RL, 44RR and on-off valves 46
FL, 46FR, 46RL, 46RR are controlled by an electric control device 50 as described in detail later. The electric control device 50 includes a microcomputer 52 and a drive circuit 54. The microcomputer 52 is not shown in detail in FIG. 1, but is, for example, a central processing unit (CPU).
, A read only memory (ROM), a random access memory (RAM), and an input / output port device, which may be of a general configuration connected to each other by a bidirectional common bus.

A signal indicating the vehicle speed V from the vehicle speed sensor 56, a signal indicating the lateral acceleration Gy of the vehicle body from a lateral acceleration sensor 58 provided substantially at the center of gravity of the vehicle body, a yaw rate sensor 60 Signal indicating the yaw rate γ of the vehicle body, the wheel speed sensor 62FL
From 62RR, signals indicating the wheel speeds (peripheral speeds) VFL, VFR, VRL, and VRR of the left and right front wheels and the left and right rear wheels are input. The lateral acceleration sensor 58 and the like detect lateral acceleration and the like with the left turning direction of the vehicle as positive.

The ROM of the microcomputer 52 stores various control flows and maps as described later, and the CPU performs various calculations as described later based on the parameters detected by the various sensors described above to execute the control of the vehicle. A spin value SV for determining the turning behavior is obtained, a turning amount of the vehicle is estimated based on the spin value, and a control amount for stabilizing the turning behavior of the vehicle is calculated.
The braking force of the left front wheel or the right front wheel is controlled based on the calculation result to stabilize the turning behavior of the vehicle.

Next, the turning behavior control of the vehicle according to the first embodiment will be described with reference to the flowcharts shown in FIGS. The control according to the flowcharts shown in FIGS. 2 and 3 is started by closing an ignition switch (not shown) and is repeatedly executed at predetermined time intervals.

First, in step 10 of the turning behavior determination routine shown in FIG. 2, a signal or the like indicating the vehicle speed V detected by the vehicle speed sensor 56 is read.
Is the product V of the lateral acceleration Gy, the vehicle speed V, and the yaw rate γ.
The deviation of lateral acceleration, that is, the lateral slip acceleration Vyd of the vehicle is calculated as the deviation Gy-V * γ from * γ, and in step 30, the deviation Vyd of the lateral acceleration is integrated to calculate the slip velocity Vy of the vehicle body. Is done. In step 40, the slip angle β of the vehicle body is defined as the ratio Vy / Vx of the vehicle body slip speed Vy to the vehicle body front-rear speed Vx (= vehicle speed V).
Is calculated in step 50, and the deviation V of the lateral acceleration calculated in step 20 with A and B as positive constants.
Based on yd and the slip angle β of the vehicle body calculated in step 40, the spin value SV is calculated according to the following equation (1).

[Equation 1] SV = A * Vyd + B * β

The calculation of the spin value SV itself 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 front outer wheel, is set to the right front wheel. When the value is negative, the left front wheel is specified. In step 70, the target slip ratio Rs of the left front wheel or the right front wheel is calculated from the map corresponding to the graph shown in FIG. 4 based on the absolute value of the spin value SV, and in step 80, the target slip ratio Rs Is determined to be 0, that is, whether or not the turning behavior of the vehicle is stable. If an affirmative determination is made, at step 85, the front-wheel-side control valves 40FL, 40FR The position is reset to one position, whereby the braking force of each wheel is controlled by the master cylinder pressure according to the amount of depression of the brake pedal 12. If a negative determination is made in step 80, a target wheel speed Vwt is calculated in step 90 according to the following equation 2 with Vin as the wheel speed of the front turning inner wheel.

## EQU2 ## Vwt = (1-Rs) * Vin

In step 100 of the brake pressure control routine shown in FIG. 3, it is determined whether or not it is time to start turning control of the vehicle, that is, an affirmative determination is made in step 80 of the previous cycle. Also, it is determined whether or not a negative determination has been made in step 80 of the current cycle.
If an affirmative determination is made at 0, then at step 110, the flag Ffa indicating that the turning behavior control has started is set to 1.

In step 120, the road surface friction coefficient μ
The vector sum (Gx ² + Gy ² ) ^1/2 of the longitudinal acceleration Gx and the lateral acceleration Gy of the vehicle body is calculated as the state quantity indicating A correction value Ga of the value Gi is calculated, and in step 130, a reference value Gi (= Gx-Ga) for determination in step 160 described later is calculated.
In this case, the magnitude of the correction value Ga is larger than the magnitude of the longitudinal acceleration Gx (negative value), and the reference value Gi is calculated as a negative value.

In step 140, it is determined whether or not the turning behavior control is being performed. If the affirmative determination is made, the process proceeds to step 170. If the negative determination is made, in step 150 the turning outer wheel is determined. It is determined whether or not the wheel speed Vw is less than the target wheel speed Vwt calculated in step 90. When an affirmative determination is made in step 150, the process proceeds to step 170, and when a negative determination is made, in step 160, the wheel speed V of the turning outer wheel is determined.
differential value of w, ie, wheel acceleration Vwd as wheel deceleration
Is calculated, and the wheel acceleration Vwd is calculated in step 130.
Determining whether or not it is less than the reference value Gi calculated in
That is, it is determined whether or not the deceleration of the turning outer wheel exceeds the reference value.
At 0, the flag Ffa is reset to 0, and when a negative determination is made, the routine proceeds to step 180 as it is.

At step 180, it is determined whether or not the flag Ffa is 1, that is, whether or not the mode is the rapid pressure increase mode at the start of the turning behavior. If an affirmative determination is made, step 190 is performed. At step 200, the duty ratio Dr of the drive current for the open / close valve of the front outer turning wheel is set to a maximum value Drmax such as 100%. If a negative determination is made, the duty ratio Dr is set at step 200 to Set according to. In the following equation (3), Vw is the wheel speed of the front turning outer wheel, Vwt is the target wheel speed calculated in step 90, and Kp and Kd are proportional to the wheel speed feedback control. It is the proportionality constant of the term and the derivative term.

## EQU3 ## Dr = Kp * (Vw-Vwt) + Kd * d (Vw
−Vwt) / dt

In step 210, a control signal is output to the control valve 40FL or 40FR of the front turning outer wheel to switch the control valve to the second position, and the front wheel turning is also performed. Duty ratio D calculated in step 190 or 200 for the open / close valve of the outer ring
By outputting the control signal corresponding to r, the supply and discharge of the accumulator pressure to the wheel cylinder 38FL or 38FR of the turning outer wheel is controlled, thereby controlling the braking pressure of the turning outer wheel.

In this case, when the duty ratio Dr calculated in step 200 is a value between the negative reference value and the positive reference value, the on-off valve on the upstream side of the turning outer wheel is switched to the second position. And the downstream open / close valve is held at the first position, the pressure in the corresponding wheel cylinder is held, and when the duty ratio is equal to or higher than the positive reference value, the upstream and downstream sides of the turning outer wheel are opened / closed. When the valve is controlled to the position shown in FIG. 1, the pressure in the wheel cylinder is increased by supplying the accumulator pressure to the corresponding wheel cylinder, and the duty ratio is equal to or less than the negative reference value. Occasionally, the on-off valves on the upstream and downstream sides of the turning outer wheel are switched to the second position, so that the brake oil in the corresponding wheel cylinder is discharged to the low-pressure conduit 42. It is, thereby the pressure within the wheel cylinder is reduced.

Thus, in the illustrated first embodiment, the target slip rate Rs of the front outer turning wheel is calculated based on the spin value SV in the turning behavior determination routine of steps 10 to 80, and the target slip rate is calculated. It is determined whether or not the turning behavior of the vehicle is stable, that is, whether or not the behavior control is unnecessary. If a negative determination is made, steps 90 to 210 are not executed Steps 10 to 85 are executed, whereby the braking pressure of each wheel is controlled in accordance with the master cylinder pressure, that is, the amount of depression of the brake pedal 12.

On the other hand, a negative decision is made in step 80,
That is, when it is determined that the behavior control is necessary, the target wheel speed Vwt of the front outer-side turning outer wheel is calculated in step 90, and when the turning behavior control is started in step 100 of the braking pressure control routine. Is determined. At the start of the turning behavior control, a positive determination is made in step 100, the flag Ffa is set to 1 in step 110, and in step 160, the deceleration Vwd of the front turning outer wheel exceeds the reference value Gi. The flag Ffa is maintained at 1 until the determination is made, and the steps 190 and 210 are executed to rapidly increase the braking pressure of the front outer turning outer wheel, thereby providing a good response at the start of the behavior control. Nature is secured.

Steps 120 and 130 in the first embodiment shown in the drawing correspond to a part of the configuration of the above-described second embodiment. In step 120, the correction value Ga increases as the friction coefficient of the road surface increases. The magnitude (absolute value) of the reference value Gi for determining the deceleration in step 130 is set to be larger as the friction coefficient of the road surface is higher. Therefore, when the friction coefficient of the road surface is high, the magnitude of the reference value Gi is set to be large, so that the braking pressure at the start of the turning behavior control can be surely rapidly increased to a sufficient value. When the value is low, the magnitude of the reference value Gi is set to a small value to prevent an excessive sudden increase in pressure, whereby the braking pressure at the start of the behavior control is rapidly increased to an optimum value according to the friction coefficient of the road surface. Can be.

FIGS. 6 and 7 are flowcharts similar to FIGS. 2 and 3 showing a turning behavior determination routine and a braking pressure control routine of the turning behavior control of the vehicle according to the second embodiment of the present invention. Steps corresponding to the steps shown in FIGS. 2 and 3 in FIGS. 6 and 7 are assigned the same step numbers as those given in FIGS. 2 and 3.

In the second embodiment, step 80
When it is determined in step 81 that the target slip ratio Rs is 0, that is, when it is determined that the vehicle is not in the spin state, Kh is set to a stability factor in step 81, and N
Is the steering gear ratio, L is the wheel base, the vehicle speed V detected by the vehicle speed sensor 56 and the steering angle θ detected by the steering angle sensor not shown in the figure.
And the target yaw rate γ according to the following equation (4) or (5)
t is calculated.

[0042]

Equation 4] γt = (V * θ) / {(1 + Kh * V 2) * N * L}

Γt = (V * θ) / (N * L) −Kh * V * Gy

In step 82, the right front wheel is set when the target yaw rate γt is positive, and the target wheel is set negative when the target yaw rate is negative. Specific to the left front wheel. In step 83, a deviation Δγ between the target yaw rate γt and the actual yaw rate γ detected by the yaw rate sensor 60 is calculated, and based on the yaw rate deviation Δγ, the target slip ratio Rs of the left front wheel or the right front wheel is shown in FIG. It is calculated from the map corresponding to the obtained graph.

In step 84, the target slip ratio Rs
Is determined, that is, whether the vehicle is not in a drift-out state. If an affirmative determination is made, in step 85, the front-wheel-side control valves 40FL, 40FL are determined.
FR is reset to the first position, whereby the braking force of each wheel is controlled by the master cylinder pressure according to the amount of depression of the brake pedal 12. When a negative determination is made in step 84, that is, when a determination is made that the vehicle is in a drift-out state, a flag F indicating that the vehicle is in a drift-out state is set to 1 in step 86, and then the step Go to 90. The flag F is reset to 0 in step 87 when a negative determination is made in step 80, that is, when it is determined that the vehicle is in a spin state.

In the second embodiment, the flag F is set at step 115 which is executed after step 110.
Is determined to be 1 or not, that is, whether the vehicle is in a drift-out state is determined, and if a negative determination is made, that is, it is determined that the vehicle is in a spin state, the routine proceeds to step 120. Similar to the first embodiment, the correction value Ga of the reference value Gi is calculated from the map corresponding to the graph shown in FIG. 5, and a positive determination is made, that is, a determination is made that the vehicle is in a drift-out state. Sometimes, in step 125, the vector of the longitudinal acceleration and the lateral acceleration of the vehicle body is (Gx ² +
Gy ² ) ^1/2 is calculated, and the reference value G is obtained from a map corresponding to the graph shown in FIG. 9 based on the vector sum.
The correction value Ga of i is calculated.

Further, in step 100 of the second embodiment, it is determined whether or not the vehicle turning behavior control is to be started at step 84 of the previous cycle. This is performed by determining whether or not a negative determination has been made in step 80 or 84.

As can be seen from a comparison between FIGS. 5 and 9, the correction value Ga when the vehicle is in a spin state (FIG. 5) is larger than the correction value when the vehicle is in a drift state (FIG. 9). The magnitude (absolute value) of the reference value Gi calculated at 130 is larger when the vehicle is in a spin state than when the vehicle is in a drift-out state, and therefore, when the vehicle is in a spin state. Since the affirmative determination is not made in step 160 until the deceleration Vwd of the turning outer wheel becomes larger than that in the drift-out state, when the vehicle is in the spin state, it is smaller than in the drift-out state. As a result, the degree of sudden increase in the braking pressure increases.

For example, FIGS. 10 and 11 are time charts showing an example of a sudden pressure increase pulse and a change in wheel speed during spin control and drift-out control, respectively.
As shown in FIG. 10, during spin control, the reference value G
By setting the magnitude (inclination) of i to be large and controlling the on-time of the rapid pressure increase pulse to be long, the degree of deceleration of the outer turning wheel on the front wheel side is greatly controlled, so it is sufficient to be prepared to lock the front wheel the behavior dynamic control start time responsiveness can be secured such.

As shown in FIG. 11, the magnitude of the reference value Gi is set to be smaller in the drift-out control than in the spin control, and the on-time of the rapid pressure increase pulse is controlled to be shorter, so that the front wheel side is controlled. Is controlled so that the degree of deceleration of the turning outer wheel does not become excessively large. Therefore, it is possible to reliably prevent the front wheel from being locked, and thereby to surely prevent the drift-out from being promoted by the turning behavior control.

According to the illustrated second embodiment, the correction value Ga is calculated in accordance with the road surface friction coefficient in both the spin control and the drift-out control, as in the first embodiment. Accordingly, the magnitude of the reference value Gi is set to be larger as the road surface friction coefficient is higher, so that the braking pressure at the start of the turning behavior control can be surely rapidly increased to a sufficient value. When the friction coefficient of the road surface is low, the reference value Gi is set to a small value to prevent an excessive sudden increase in pressure, whereby the braking pressure at the start of the behavior control is set to an optimum value according to the friction coefficient of the road surface. Can be rapidly increased.

In the illustrated first and second embodiments,
The determination as to whether or not the turning behavior of the vehicle is stable, that is, whether or not the turning behavior control is unnecessary, is performed in step 80 by determining whether or not the target slip ratio Rs is zero. However, this determination may be made by determining whether or not the spin value SV is equal to or less than a predetermined value SVo.

In the illustrated first and second embodiments, regardless of whether or not a braking operation is performed by the driver, the road surface is determined based on the vector sum of the longitudinal acceleration Gx and the lateral acceleration Gy of the vehicle body. Although the friction coefficient is estimated, in order to more accurately estimate the friction coefficient of the road surface, in the first embodiment, a brake switch (not shown) is shown prior to step 120. Is determined whether or not the brake switch is on. If the brake switch is off, step 120 is executed. If the brake is on, the correction value Ga is set to a predetermined constant value and then step 130 It may be configured to proceed to

Similarly, in the second embodiment, step 1
Prior to steps 20 and 125, it is determined whether or not the brake switch is on. If the brake switch is off, step 120 or 125 is executed. If the brake switch is on, the correction value Ga is constant. May be configured to proceed to step 130 after being set to the predetermined value. In this case, the constant correction value Ga set when the affirmative determination is made in step 115
Is set to be smaller than the fixed correction value set when the negative determination is made in step 115.

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 each of the above-described embodiments, when the turning behavior of the vehicle becomes unstable, the braking force of the front outer wheel is controlled in accordance with the spin value SV, and the braking force of the front outer wheel is controlled. Although the spin is reduced by the anti-spin moment due to the difference between the power and the braking force of the turning inner wheel, the braking force of both the front wheel side and the rear wheel side turning outer wheel may be controlled.

In each of the above-described embodiments, the target wheel speed Vwt is calculated based on the wheel speed Vin of the front turning inner wheel in accordance with Formula 2 as a reference value. May be configured to be calculated on the basis of.

Further, in each of the above-described embodiments, the hydraulic pressure supplied to each wheel cylinder is the hydraulic pressure from the master cylinder 14 or the hydraulic pressure stored in the accumulator 36. May be applied to a vehicle incorporating an ABS (anti-lock brake system) in which the pressure in the wheel cylinder is increased as necessary by the regulator pressure corresponding to the above.

[0058]

As is apparent from the above description, according to the first aspect of the present invention, the rapid pressure increasing means detects the deceleration of the wheel at the start of the spin suppression control, and detects the detected wheel speed.
Increase the braking pressure until the deceleration exceeds the reference value
By than that push sharp increase the braking pressure to a predetermined value necessary to perform a spin suppress control with effective beyond the dead zone of the brake mechanism, spin suppression control while setting the gain of the spin suppress control to an appropriate value The braking pressure at the start of the control can be rapidly increased to a value required for performing the effective spin suppression control without any excess or shortage , thereby improving the responsiveness at the start of the spin suppression control. It is possible to surely prevent the target followability of the braking pressure control of the spin suppression control after the rapid pressure increase from being deteriorated due to the control gain being too high, and to control the braking pressure to an optimum value. Spin suppression control can be favorably performed.

According to the second aspect of the present invention, the behavior control device further includes a means for detecting a road surface friction coefficient, and the sudden pressure increasing means sets the predetermined value to be larger as the road surface friction coefficient is higher. Therefore, when the friction coefficient of the road surface is high, the predetermined value is set to be large, so that the braking pressure at the start of the spin suppression control can be adjusted to a value necessary for performing the effective spin suppression control. When the friction coefficient of the road surface is low, the predetermined value is set to a small value to prevent excessive sudden pressure increase, thereby preventing the brake pressure at the start of the spin suppression control from being reduced by the friction coefficient of the road surface. Can be rapidly increased to an optimum value.

According to a third aspect of the present invention, in the first or second aspect, the behavior control means is configured to control the braking pressure based on a wheel slip ratio according to the spin state amount. Since the braking pressure at the start of the spin suppression control is rapidly increased to a value required for performing the effective spin suppression control without any excess or shortage according to the configuration of claim 1 or 2, the target wheel at the beginning of the control is controlled. It is possible to reduce the possibility that the response of the spin suppression control is delayed due to a large deviation between the actual speed and the actual wheel speed, thereby improving the response at the start of the spin suppression control.

[0061]

According to the fourth aspect of the present invention, when the estimated turning behavior of the vehicle is in the spin state, the braking pressure is rapidly increased by the abrupt pressure increasing means as compared with the case where the turning behavior is in the drift-out state. since a surge圧度if changing means for increasing a degree, sufficient responsiveness levator dynamic control start time <br/> in prepared to the front wheels to lock when turning behavior of the vehicle is in a spin state It can be secured, that the turning behavior reliably prevents the front wheels to lock when a drift-out state, is Rikyo dynamic control by the this reliably prevented that promotes drift-out state Can be.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the sudden pressure increasing means is provided when the behavior control is started.
Detects wheel deceleration and uses the detected wheel deceleration as a reference
Since the brake pressure is suddenly increased to a predetermined value required for effective behavior control beyond the dead zone of the brake mechanism by increasing the brake pressure until the value exceeds the value, the gain of the behavior control is increased. To the appropriate value.
The braking pressure at the start of the behavior control is
The pressure can be rapidly increased to the value required for
This can improve responsiveness at the start of behavior control.
And the control gain is too high.
Poor target tracking of braking pressure control in behavior control after pressure increase
And control the braking pressure to an optimal value.
Behavior control can be satisfactorily executed, and the rapid pressure increasing means is configured to rapidly increase the braking pressure to a predetermined value necessary for performing effective behavior control beyond the dead zone region of the brake mechanism, The sudden pressure increase degree changing means is configured to set the predetermined value larger when the estimated turning behavior of the vehicle is in the spin state than in the case where the turning behavior is in the drift-out state. When the turning behavior is in the spin state, the degree of sudden increase of the braking pressure by the sudden pressure increasing means can be reliably increased as compared with the case where the turning behavior is in the drift-out state. The effect can be obtained reliably.

[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 illustrating a behavior determination routine of turning behavior control according to the first embodiment of the behavior control device according to the present invention.

FIG. 3 is a flowchart showing a braking pressure control routine of turning behavior control according to the first embodiment of the behavior control device according to the present invention.

FIG. 4 is a graph showing a relationship between an absolute value of a spin value SV and a target slip ratio Rs.

FIG. 5 is a graph showing a relationship between a vector sum of a longitudinal acceleration Gx and a lateral acceleration GY of a vehicle body for spin control and a correction value Ga.

FIG. 6 is a flowchart showing a turning behavior determination routine of turning behavior control of a vehicle according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a braking pressure control routine of turning behavior control according to a second embodiment of the behavior control device according to the present invention.

FIG. 8 is a graph showing a relationship between a yaw rate deviation Δγ and a target slip ratio Rs.

FIG. 9 is a graph showing the relationship between the vector sum of the longitudinal acceleration Gx and the lateral acceleration GY of the vehicle body for drift-out control and the correction value Ga.

FIG. 10 is a time chart showing an example of a sudden pressure increase pulse and a change in wheel speed during spin control.

FIG. 11 is a time chart showing an example of a sudden pressure increase pulse and a change in wheel speed during drift-out control.

FIG. 12 is a graph showing a relationship between a brake oil amount and an actual braking pressure.

[Explanation of symbols]

 10: Braking device 14: Master cylinder 18, 20, 26, 28 ... Brake hydraulic pressure control device 34: Oil pump 38FL, 38FR, 38RL, 38RR: Wheel cylinder 40FL, 40FR, 40RL, 40RR: Control valve 44FL, 44FR, 44RL, 44RR ... On-off valve 46FL, 46FR, 46RL, 46RR ... On-off valve 50 ... Electric control device 56 ... Vehicle speed sensor 58 ... Lateral acceleration sensor 60 ... Yaw rate sensor 62FL-62RR ... Wheel speed sensor

Continuation of front page (56) References JP-A-4-362456 (JP, A) JP-A-3-109157 (JP, A) JP-A-5-85327 (JP, A) JP-A-5-319126 (JP) JP-A-62-216856 (JP, A) JP-A-2-175439 (JP, A) JP-A-6-65131 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B60T 8/00-8/96

Claims (5)

(57) [Claims] A spin estimating means for estimating a spin state based on a spin state quantity indicating a turning behavior of a vehicle, and a spin suppression control by controlling a braking pressure of a brake mechanism of each wheel according to the spin state quantity. A behavior control means to be executed ;
Sudden increase of the braking pressure at the start of the spin suppression control
At a behavior control device of a vehicle having a pressure means, the surge
The pressure means controls the wheel deceleration at the start of the spin suppression control.
Until the detected wheel deceleration exceeds the reference value
Behavior control device of a vehicle, wherein the benzalkonium the male surge braking pressure to a predetermined value necessary to perform a spin control with effective beyond the dead zone of the brake mechanism by pressure surge the braking pressure. 2. The vehicle behavior control device according to claim 1, wherein said behavior control device further comprises means for detecting a friction coefficient of a road surface, and said sudden pressure increasing means is adapted to increase the predetermined value as the friction coefficient of the road surface increases. A vehicle behavior control device characterized in that the value is set to be large. 3. The vehicle behavior control device according to claim 1, wherein the behavior control means is configured to control a braking pressure based on a wheel slip ratio corresponding to the spin state amount. Characteristic vehicle behavior control device. 4. A behavior estimating means for estimating a turning behavior of a vehicle based on a parameter indicating the turning behavior of the vehicle, and a braking mechanism for a front wheel brake mechanism according to the parameter when the estimated turning behavior of the vehicle is unstable. Behavior control means for performing behavior control by controlling pressure, and the behavior control
The ratio of the beginning At a behavior control device of a vehicle and a rapid increase means for pressurizing surge brake pressure, if turning behavior of the estimated been vehicle is spin state when the turning behavior is a drift-out state behavior control device of a vehicle which is characterized in that it has a rapid increase圧度focus change means to increase the surge圧度case of brake pressure by the rapid increase means. 5. The vehicle behavior control device according to claim 4, wherein said sudden pressure increasing means controls the deceleration of the wheel at the start of said behavior control.
Until the detected wheel deceleration exceeds the reference value
The brake pressure is rapidly increased to a predetermined value required for performing effective behavior control beyond the dead zone region of the brake mechanism by rapidly increasing the brake pressure. The behavior control device for a vehicle, wherein the predetermined value is set to be larger when the turning behavior of the performed vehicle is a spin state than when the turning behavior is a drift-out state.