JP4759864B2 - Brake control device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a braking control device for a vehicle such as an automobile, and more particularly to a braking control device for ensuring running stability of a vehicle during turning braking of the vehicle.
[0002]
[Prior art]
As one of the braking control devices for vehicles such as automobiles, for example, as described in Japanese Patent Application Laid-Open No. 6-127354, front and rear wheels of braking force are set so that the yaw rate of the vehicle becomes a steady target yaw rate during vehicle turning braking. 2. Description of the Related Art A braking control device that controls a distribution ratio is conventionally known. According to this braking control device, it is possible to prevent the yaw rate of the vehicle from increasing during the turning braking of the vehicle, and to improve the running stability during the turning braking of the vehicle.
[0003]
[Problems to be solved by the invention]
However, in the conventional braking control device described in the above publication, the front / rear wheel distribution ratio of the braking force is controlled closer to the front wheel so that the yaw rate of the vehicle becomes a steady target yaw rate. Even if the steering wheel is increased (additional steering) to actively turn the vehicle, the magnitude of the yaw rate of the vehicle does not increase effectively, and therefore the driver's intention to promote turning cannot be preferably reflected. There is.
[0004]
In particular, the braking force of the rear wheels is not reduced so that the deceleration of the vehicle is not lowered by controlling the front-rear wheel distribution ratio of the braking force. For example, the specification of Japanese Patent Application No. 2001-175401 relating to the prior application of the applicant of the present application. As shown in the drawings, the front-rear wheel distribution ratio of the braking force is increased so that the front-wheel braking force distribution ratio with respect to the rear wheel is increased by increasing at least the front-wheel braking force based on the state of the vehicle during turning braking of the vehicle. When the vehicle is controlled, the front wheel lateral force is reduced and the front wheel lateral force is reduced, and the yaw moment in the turning direction of the vehicle is reduced. Therefore, the above problem increases at least the front wheel braking force. This is remarkable when the front / rear wheel distribution ratio of the braking force is controlled so that the distribution ratio of the braking force of the front wheel to the rear wheel is increased.
[0005]
The present invention has been made in view of the above-described problems in the conventional braking control device that performs the braking force distribution adjustment control of the front and rear wheels based on the state of the vehicle during turning braking of the vehicle. Ensures the vehicle's running stability during turning braking of the vehicle by changing the contents of wheel braking force control during braking force distribution adjustment control of the front and rear wheels according to the driver's intention to promote turning In addition, the driver's willingness to promote turning should be reflected reliably.
[0006]
[Means for Solving the Problems]
  According to the present invention, the main problem described above is the operation of the above-described configuration of claim 1, that is, the vehicle braking control device that performs braking force distribution adjustment control of the front and rear wheels based on the state of the vehicle at the time of vehicle turning braking. Determining means for determining the presence or absence of the driver's intention to promote turning, wherein the determining means determines that the driver is willing to promote turning when the vehicle is in an understeer state and additional steering is performed by the driver, When it is determined by the determination means that the driver has a willingness to turn, the braking force of the steering wheel is set lower than the value of the braking force distribution adjustment control of the front and rear wheels.The braking force distribution adjustment control for the front and rear wheels controls the distribution ratio so that the distribution ratio of the braking force of the front wheels to the rear wheels increases as the product of the lateral acceleration of the vehicle and the vehicle speed increases.A braking control device for a vehicle, or the above claim2The vehicle braking control device performs the braking force distribution adjustment control of the front and rear wheels based on the state of the vehicle at the time of turning braking of the vehicle, and includes means for determining the presence or absence of the driver's intention to promote turning. When it is determined that there is a willingness to turn, the braking force of the steered wheels is made lower than the value of the braking force distribution adjustment control of the front and rear wheels, and the braking force distribution adjustment control of the front and rear wheels is set between the lateral acceleration of the vehicle and the vehicle speed. This is achieved by a vehicle braking control device that controls the distribution ratio so that the distribution ratio of the braking force of the front wheels to the rear wheels increases as the size of the product increases.
[0007]
Further, according to the present invention, in order to effectively achieve the above main problem, in the configuration of claim 1, the front and rear wheel braking force distribution adjustment control is performed by the front wheel braking force distribution ratio with respect to the rear wheel. The braking force of at least one wheel is controlled so as to be high (configuration of claim 2).
[0008]
According to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 2, the control amount of the front and rear wheel braking force distribution adjustment control is reduced to reduce the front wheel control. It is comprised so that motive power may be made low (structure of Claim 3).
[0009]
Further, according to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 2 or 3, the braking force distribution adjustment control of the front and rear wheels is performed between the lateral acceleration of the vehicle and the vehicle speed. The distribution ratio is controlled so that the distribution ratio of the braking force of the front wheels to the rear wheels becomes higher as the size of the product is larger (configuration of claim 4).
[0010]
[Action and effect of the invention]
  According to the first aspect of the present invention, the presence or absence of the driver's intention to promote turning is determined, and when it is determined that the driver has the intention to promote turning, the braking force of the steering wheel is determined from the value of the braking force distribution adjustment control of the front and rear wheels. Therefore, it is possible to reduce the braking force of the steered wheel and increase its lateral force, thereby increasing the yaw moment in the turning direction of the vehicle, and thus surely reflecting the driver's intention to promote turning. Can do.
  According to the first aspect of the present invention, since it is determined that the driver is willing to turn when the vehicle is understeered and additional steering is performed by the driver, is the driver's intention to promote turning? Compared to the case where the determination of whether or not additional steering is performed by the driver, whether or not the driver is willing to turn, that is, whether the vehicle is going to turn more than the current state It is possible to accurately determine whether or not.
  Further, according to the first aspect, the braking force distribution adjustment control for the front and rear wheels is performed so that the distribution ratio of the braking force of the front wheels to the rear wheels increases as the product of the lateral acceleration and the vehicle speed of the vehicle increases. Therefore, as will be described in detail later, it is possible to easily and effectively prevent an increase in yaw rate during turning braking without requiring a complicated calculation.
  Further, according to the second aspect, as in the case of the first aspect, the braking force of the steered wheels can be reduced to increase the lateral force, thereby increasing the yaw moment in the turning direction of the vehicle, Accordingly, the driver's intention to promote turning can be reliably reflected. As in the case of claim 1, the yaw rate during turning braking can be easily and effectively prevented without requiring a complicated calculation.
[0011]
  And the above claims3According to the present invention, the braking force distribution adjustment control for the front and rear wheels controls the braking force of at least one wheel so that the distribution ratio of the braking force of the front wheel to the rear wheel is increased. When there is no driver's willingness to turn during the turning braking, the yaw rate of the vehicle is surely prevented, and when there is a driver's willingness to turn, the turning promotion intention should be reflected surely Can do.
[0012]
  And the above claims4The steering wheel is a front wheel, and the braking force of the front wheel is reduced by reducing the control amount of the braking force distribution adjustment control of the front and rear wheels. In addition, it is possible to reliably reduce the possibility that the driver's intention to promote turning will be difficult to be reflected due to the execution of the braking force distribution adjustment control for the front and rear wheels as they are.
[0013]
  According to the fourth aspect of the invention, the braking force distribution adjustment control for the front and rear wheels is performed so that the distribution ratio of the braking force of the front wheels to the rear wheels increases as the product of the lateral acceleration and the vehicle speed of the vehicle increases. Therefore, as will be described in detail later, it is possible to easily and effectively prevent an increase in yaw rate during turning braking without requiring a complicated calculation.
  Further, according to claim 5, as in the case of claim 1, the braking force of the steered wheel is reduced to increase its lateral force, thereby increasing the yaw moment in the turning direction of the vehicle, Accordingly, the driver's intention to promote turning can be reliably reflected. As in the case of claim 1, the yaw rate during turning braking can be easily and effectively prevented without requiring a complicated calculation.
[0014]
Next, prior to the description of the embodiment of the braking control apparatus according to the present invention, the principle of the structure of the above-mentioned claim 4 will be described. According to the vehicle model, if the stability factor is Kh, the vehicle speed is V, the steering angle is θ, the steering gear ratio is N, and the vehicle wheelbase is L, the vehicle yaw rate Yr is given by expressed.
Yr = {1 / (1 + Kh × V × V)} × (θ × V) / (N × L) (1)
[0015]
When (1 + Kh × V × V) is applied to both sides of the above formula 1, the following formula 2 is obtained. When the lateral acceleration of the vehicle is Gy, the following formula 3 is obtained from the relationship of Gy = Yr × V.
Yr + Kh × (Yr × V) × V = (θ × V) / (N × L) (2)
Yr = (θ × V) / (N × L) −Kh × Gy × V (3)
[0016]
In general, in an actual vehicle, when the vehicle is braked during steady turning, a phenomenon in which the vehicle tries to enter the inside of the turn despite a constant steering angle, that is, an undesired phenomenon in which the yaw rate Yr becomes large occurs. .
[0017]
If this phenomenon is applied to the above equation 3, assuming that the yaw rate before braking is Yr1, the yaw rate after braking is Yr2, and the change in vehicle speed before and after braking is small, these yaw rates are expressed by the following equations 4 and 5, respectively. It is represented by
Yr1 = (θ × V) / (N × L) −Kh1 × Gy × V (4)
Yr2 = (θ × V) / (N × L) −Kh2 × Gy × V (5)
The increase in the yaw rate Yr in the above phenomenon is Yr2> Yr1, and in order to suppress the increase in the yaw rate Yr, the value of the change amount of the yaw rate expressed by the following equation 6 may be reduced.
Yr2−Yr1 = (Kh1−Kh2) × Gy × V (6)
[0018]
It has been confirmed in actual vehicles that the stability factor Kh tends to increase as the front-rear wheel distribution ratio of the braking force becomes closer to the front wheels. Therefore, in order to suppress an increase in the yaw rate Yr after braking during turning of the vehicle, the larger the product Gy × V of the lateral acceleration Gy and the vehicle speed V of the vehicle, the smaller (Kh1−Kh2). That is, it is only necessary to control the front / rear wheel distribution ratio of the braking force closer to the front wheels, and this control requires a complicated calculation as compared with the case of the braking control device described in the above-mentioned JP-A-6-127354. Therefore, an increase in yaw rate during turning braking can be easily and effectively prevented.
[0020]
[Preferred embodiment of the problem solving means]
  According to one preferred embodiment of the present invention, the above claims3In this configuration, the braking force distribution adjustment control of the front and rear wheels is configured to increase at least the braking force of the front wheels so that the distribution ratio of the braking force of the front wheels to the rear wheels is increased (preferred aspect 1).
[0021]
  According to another preferred embodiment of the present invention, the preferred embodiment described above.1In this configuration, when the amount of braking operation by the driver is high, the braking force of the front wheel based on the product of the lateral acceleration of the vehicle and the vehicle speed is controlled so as to prevent the braking force of the front wheel from exceeding a predetermined range. Configured to compensate for increase (preferred embodiment2).
[0022]
  According to another preferred embodiment of the invention, the above claims4In the configuration, the control amount of the braking force distribution adjustment control for the front and rear wheels is configured to be reduced to 0 (preferred aspect 3).
[0023]
  According to another preferred embodiment of the invention, the above claims1Or2In this configuration, the front and rear wheel braking force distribution adjustment control is performed when the product of the lateral acceleration and the vehicle speed of the vehicle is greater than or equal to the first reference value and less than the second reference value. When the product of the lateral acceleration and the vehicle speed of the vehicle is greater than or equal to the second reference value, the front wheel braking force is increased and the rear wheel braking force is reduced. (Preferred embodiment 4).
[0024]
  According to another preferred embodiment of the present invention, the preferred embodiment described above.4In this configuration, when the product of the vehicle lateral acceleration and the vehicle speed is greater than or equal to the second reference value, the rate of increase of the braking force of the front wheels with respect to the product of the vehicle lateral acceleration and the vehicle speed is The product of the lateral acceleration and the vehicle speed of the vehicle is configured to be smaller than the case where the magnitude of the product is greater than or equal to the first reference value and less than the second reference value.5).
[0025]
  According to another preferred embodiment of the present invention, the preferred embodiment described above.4In this configuration, the braking force control means controls the rear inner wheel so that the larger the product is, the smaller the product of the lateral acceleration and the vehicle speed of the vehicle is equal to or greater than the second reference value. Configured to reduce power (preferred embodiment6).
[0026]
  According to another preferred embodiment of the present invention, the preferred embodiment described above.4In this configuration, the braking force control means controls the rear inner wheel so that the larger the product is, the smaller the product of the lateral acceleration and the vehicle speed of the vehicle is equal to or greater than the second reference value. It is configured to reduce the power and increase the braking force of the rear outer wheel so as to increase as the size of the product increases.7).
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0028]
FIG. 1 is a schematic configuration diagram showing a hydraulic circuit and an electronic control device of one embodiment of a braking control device according to the present invention, and FIG. 2 is an illustrative sectional view showing a control valve for a front wheel shown in FIG. . In FIG. 1, the solenoid of each valve that is electromagnetically driven is not shown.
[0029]
In FIG. 1, reference numeral 10 denotes a hydraulic braking device, and the braking device 10 has a master cylinder 14 that pumps brake oil in response to a depression operation of a brake pedal 12 by a driver. The master cylinder 14 has a first master cylinder chamber 14A and a second master cylinder chamber 14B defined by free pistons 16 biased to predetermined positions by compression coil springs on both sides thereof.
[0030]
One end of a front wheel brake hydraulic control conduit 18F is connected to the first master cylinder chamber 14A, and the other brake brake control conduit 18F is connected to the left front wheel brake hydraulic control conduit 20FL and the right front wheel brake hydraulic control. One end of the conduit 20FR is connected. A control valve 22F for the front wheel, which is a normally open type electromagnetic on-off valve, is provided in the middle of the brake hydraulic control conduit 18F. Connected to the brake hydraulic control conduits 18F on both sides of the control valve 22F are check bypass conduits 24F that allow only the flow of oil from the first master cylinder chamber 14A toward the brake hydraulic control conduit 20FL or the brake hydraulic control conduit 20FR. .
[0031]
As schematically shown in FIG. 2, the control valve 22F has a housing 72 that defines a valve chamber 70 therein, and a valve element 74 is disposed in the valve chamber 70 so as to be capable of reciprocating. A portion 18FA of the brake hydraulic pressure control conduit 18F on the master cylinder 14 side is always connected to the valve chamber 70 via an internal passage 76, and a portion 18FB of the brake hydraulic pressure control conduit 18F opposite to the master cylinder 14 is internally connected. A communication connection is established via a passage 78 and a port 80.
[0032]
As shown in the figure, a solenoid 82 is disposed around the valve element 74, and the valve element 74 is urged to a valve opening position shown in FIG. 2 by a compression coil spring 84. When a drive voltage is applied to the solenoid 82, the valve element 74 is urged against the port 80 against the spring force of the compression coil spring 84, thereby closing the port 80.
[0033]
In the situation where the control valve 22F is in the closed position, the sum of the force due to the pressure in the portion 18FB on the opposite side of the master cylinder 14 of the brake hydraulic control conduit 18F and the spring force of the compression coil spring 84 is the solenoid 82. The valve element 74 opens away from the port 80, and the oil in the portion 18FB passes through the internal passage 78, the port 80, the valve chamber 70, the internal passage 76, and the brake hydraulic control conduit 18F. Flow to portion 18FA. When the oil pressure in the portion 18FB decreases due to this oil flow, the sum of the force by the pressure and the spring force of the compression coil spring 84 becomes lower than the electromagnetic force by the solenoid 82, and the valve element 74 causes the port 80 to Close again.
[0034]
Thus, since the control valve 22F controls the pressure in the portion 18FB of the brake hydraulic control conduit 18F according to the voltage applied to the solenoid 82, the control valve 22F controls the pressure in the portion 18FB by controlling the driving voltage for the solenoid 82 ( In the present specification, the "upstream pressure") can be controlled to a desired pressure.
[0035]
In the illustrated embodiment, the check bypass conduit 24F shown in FIG. 1 is built in the control valve 22F, and is provided with an internal passage 86 and a portion 18FB from the valve chamber 70 provided in the middle of the internal passage. It consists of a check valve 88 that allows only the flow of oil toward.
[0036]
Wheel cylinders 26FL and 26FR for controlling the braking force of the left front wheel and the right front wheel are connected to the other ends of the brake hydraulic control conduit 20FL for the left front wheel and the brake hydraulic control conduit 20FR for the right front wheel, respectively. In the middle of the brake hydraulic pressure control conduit 20FL and the right front wheel brake hydraulic pressure control conduit 20FR, normally open solenoid valves 28FL and 28FR are provided, respectively. Connected to the brake hydraulic control conduits 20FL and 20FR on both sides of the electromagnetic on-off valves 28FL and 28FR are check bypass conduits 30FL and 30FR that permit only the flow of oil from the wheel cylinders 26FL and 26FR toward the brake hydraulic control conduit 18F, respectively. .
[0037]
One end of an oil discharge conduit 32FL is connected to the brake hydraulic control conduit 20FL between the electromagnetic on-off valve 28FL and the wheel cylinder 26FL, and oil is discharged to the brake hydraulic control conduit 20FR between the electromagnetic on-off valve 28FR and the wheel cylinder 26FR. One end of the conduit 32FR is connected. Normally closed solenoid valves 34FL and 34FR are provided in the middle of the oil discharge conduits 32FL and 32FR, respectively, and the other ends of the oil discharge conduits 32FL and 32FR are connected to a front wheel buffer reservoir 38F by a connection conduit 36F. ing.
[0038]
As understood from the above description, the electromagnetic on-off valves 28FL and 28FR are pressure-increasing valves for increasing or maintaining the pressure in the wheel cylinders 26FL and 26FR, respectively, and the electromagnetic on-off valves 34FL and 34FR are in the wheel cylinders 26FL and 26FR, respectively. Therefore, the electromagnetic on-off valves 28FL and 34FL cooperate with each other to define an increasing / decreasing valve for increasing and decreasing the pressure in the wheel cylinder 26FL of the left front wheel, The electromagnetic open / close valves 28FR and 34FR cooperate with each other to define a pressure increasing / reducing valve for increasing and decreasing the pressure in the wheel cylinder 26FR of the right front wheel.
[0039]
The connection conduit 36F is connected to the suction side of the pump 42F by the connection conduit 40F, and two check valves 44F and 46F that allow only the flow of oil from the connection conduit 36F to the pump 42F are provided in the connection conduit 40F. It has been. The discharge side of the pump 42F is connected to the brake hydraulic control conduit 18F by a connection conduit 50F having a damper 48F on the way. A connection conduit 50F between the pump 42F and the damper 48F is provided with a check valve 52F that allows only the flow of oil from the pump 42F toward the damper 48F.
[0040]
One end of a connection conduit 54F is connected to the connection conduit 40F between the two check valves 44F and 46F, and the other end of the connection conduit 54F is a brake between the first master cylinder chamber 14A and the control valve 22F. It is connected to the hydraulic control conduit 18F. A normally closed electromagnetic on-off valve 60F is provided in the middle of the connecting conduit 54F. The electromagnetic on-off valve 60F functions as a pump intake valve that controls communication between the brake hydraulic control conduit 18F between the master cylinder 14 and the control valve 22F and the intake side of the pump 42F.
[0041]
Similarly, one end of a brake oil pressure control conduit 18R for the rear wheel is connected to the second master cylinder chamber 14B, and the brake oil pressure control conduit 20RL for the left rear wheel and the right rear wheel are connected to the other end of the brake oil pressure control conduit 18R. One end of a brake hydraulic control conduit 20RR for the wheel is connected. A control valve 22R for a rear wheel, which is a normally open type electromagnetic on-off valve, is provided in the middle of the brake hydraulic control conduit 18R.
[0042]
The control valve 22R has the same structure as that shown in FIG. 2 with respect to the control valve 22F for the front wheels. Therefore, by controlling the driving voltage for the solenoid not shown in the figure, the control valve 22R The pressure (upstream pressure) in the brake hydraulic control conduit 18R on the downstream side can be controlled to a desired pressure. Furthermore, a check bypass conduit 24R that allows only the flow of oil from the second master cylinder chamber 14B to the brake hydraulic control conduit 20RL or the brake hydraulic control conduit 20RR is connected to the brake hydraulic control conduit 18R on both sides of the control valve 22R. Yes.
[0043]
Wheel cylinders 26RL and 26RR for controlling the braking force of the left rear wheel and the right rear wheel are connected to the other ends of the brake hydraulic control conduit 20RL for the left rear wheel and the brake hydraulic control conduit 20RR for the right rear wheel, respectively. In the middle of the brake hydraulic pressure control conduit 20RL for the left rear wheel and the brake hydraulic pressure control conduit 20RR for the right rear wheel, normally open type electromagnetic on-off valves 28RL and 28RR are provided, respectively. Connected to the brake hydraulic control conduits 20RL and 20RR on both sides of the electromagnetic on-off valves 28RL and 28RR are check bypass conduits 30RL and 30RR that permit only the flow of oil from the wheel cylinders 26RL and 26RR toward the brake hydraulic control conduit 18R, respectively. .
[0044]
One end of an oil discharge conduit 32RL is connected to the brake hydraulic control conduit 20RL between the electromagnetic on-off valve 28RL and the wheel cylinder 26RL, and oil is discharged to the brake hydraulic control conduit 20RR between the electromagnetic on-off valve 28RR and the wheel cylinder 26RR. One end of the conduit 32RR is connected. In the middle of the oil discharge conduits 32RL and 32RR, normally closed electromagnetic on-off valves 34RL and 34RR are provided, respectively, and the other ends of the oil discharge conduits 32RL and 32RR are connected to a rear wheel buffer reservoir 38R by a connection conduit 36R. Has been.
[0045]
As in the case of the front wheel side, the electromagnetic on-off valves 28RL and 28RR are pressure-increasing valves for increasing or maintaining the pressure in the wheel cylinders 26RL and 26RR, respectively. The electromagnetic on-off valves 34RL and 34RR are in the wheel cylinders 26RL and 26RR, respectively. Therefore, the electromagnetic on-off valves 28RL and 34RL cooperate with each other to define an increase / decrease valve for increasing and decreasing the pressure in the wheel cylinder 26RL of the left rear wheel. The electromagnetic on-off valves 28RR and 34RR cooperate with each other to define an increasing / decreasing valve for increasing and decreasing the pressure in the wheel cylinder 26RR of the right rear wheel.
[0046]
The connecting conduit 36R is connected to the suction side of the pump 42R by a connecting conduit 40R, and two check valves 44R and 46R that allow only the flow of oil from the connecting conduit 36R to the pump 42R are provided in the connecting conduit 40R. It has been. The discharge side of the pump 42R is connected to the brake hydraulic control conduit 18R by a connection conduit 50R having a damper 48R on the way. A connection conduit 50R between the pump 42R and the damper 48R is provided with a check valve 52R that allows only an oil flow from the pump 42R to the damper 48R. The pumps 42F and 42R are driven by a common electric motor not shown in FIG.
[0047]
One end of a connection conduit 54R is connected to the connection conduit 40R between the two check valves 44R and 46R, and the other end of the connection conduit 54R is a brake between the second master cylinder chamber 14B and the control valve 22R. It is connected to the hydraulic control conduit 18R. A normally closed electromagnetic on-off valve 60R is provided in the middle of the connecting conduit 54R. This electromagnetic on-off valve 60R also functions as a pump intake valve that controls communication between the brake hydraulic pressure control conduit 18R between the master cylinder 14 and the control valve 22R and the intake side of the pump 42R.
[0048]
In the illustrated embodiment, each control valve and each on-off valve is set to the non-control position shown in FIG. 1 when the drive current is not applied to the corresponding solenoid, whereby the wheel cylinders 26FL and 26FR are set. The pressure in the first master cylinder chamber 14A is supplied, and the pressure in the second master cylinder chamber 14B is supplied to the wheel cylinders 26RL and 26RR. Therefore, at normal times, the pressure in the wheel cylinder of each wheel, that is, the braking force is increased or decreased according to the depression force of the brake pedal 12.
[0049]
On the other hand, the control valves 22F and 22R are switched to the closed position, the on-off valves 60F and 60R are opened, and the pumps 42F and 42R are driven in a state where the on-off valves of the wheels are at the positions shown in FIG. Then, the oil in the master cylinder 14 is pumped up by the pump, the pressure pumped up by the pump 42F is supplied to the wheel cylinders 26FL and 26FR, and the pressure pumped up by the pump 42R is supplied to the wheel cylinders 26RL and 26RR. Therefore, the braking pressure of each wheel is increased / decreased by opening / closing the control valves 22F, 22R and the opening / closing valves (increasing / decreasing valves) of each wheel regardless of the depression force of the brake pedal 12.
[0050]
In this case, the pressure in the wheel cylinder is increased when the on-off valves 28FL to 28RR and the on-off valves 34FL to 34RR are in the non-control position shown in FIG. 1 (pressure increasing mode), and the on-off valves 28FL to 28RR are closed. When it is switched to the valve position and the on-off valves 34FL to 34RR are in the non-control position shown in FIG. 1, it is held (holding mode), and the on-off valves 28FL to 28RR and the on-off valves 34FL to 34RR are switched to the open position. The pressure is reduced (pressure reduction mode).
[0051]
The control valves 22F and 22R, the open / close valves 28FL to 28RR, the open / close valves 34FL to 34RR, and the open / close valves 60F and 60R are controlled by the electronic control unit 90 as described later. The electronic control unit 90 includes a microcomputer 92 and a drive circuit 94, and the microcomputer 92 may have a general configuration well known in the art.
[0052]
The microcomputer 92 has a signal indicating the master cylinder pressure Pm from the pressure sensor 96, a signal indicating the lateral acceleration Gy of the vehicle from the lateral acceleration sensor 98, a signal indicating the yaw rate Yr of the vehicle from the yaw rate sensor 100, and a steering angle from the steering angle sensor 102. A signal indicating θ, a signal indicating the vehicle speed V from the vehicle speed sensor 104, and a signal indicating whether or not the stop lamp switch is on are input from the stop lamp switch (STPSW). The microcomputer 92 stores a braking control flow, which will be described later, calculates target braking pressures Pti (i = fl, fr, rl, rr) for the left and right front wheels and the left and right rear wheels according to the braking control flow, and controls the control valve 22F. Etc., the braking pressure Pi of each wheel (i = fl, fr, rl, rr) is controlled to the corresponding target braking pressure Pti.
[0053]
Particularly in the illustrated embodiment, the electronic control unit 90 calculates the target braking pressure Pti of each wheel in accordance with the braking operation amount (master cylinder pressure Pm) of the driver, and the braking slip of the wheel is excessive. Sometimes, a target braking pressure Pti for reducing braking slip is calculated, and thereby anti-skid control (indicated as ABS control in the figure) is performed.
[0054]
In the illustrated embodiment, when the vehicle is in the turning braking state, the electronic control unit 90 increases the braking pressure of the front wheels as the product Gy × V of the lateral acceleration Gy of the vehicle and the vehicle speed V increases. When the product Gy × V is very large, the braking pressure on the rear rear wheel is fully reduced, so that if the driver performs a braking operation while turning the vehicle, By controlling the power front / rear wheel distribution ratio closer to the front wheels, the front / rear wheel distribution control of the braking force during turning braking is performed to prevent the yaw rate of the vehicle from increasing.
[0055]
Further, in the illustrated embodiment, the electronic control unit 90 determines whether or not the driver is willing to turn by determining whether or not the vehicle is understeered and additional steering is performed by the driver. However, when the driver is willing to turn, the control of the front / rear wheel distribution ratio is not performed by controlling the braking force of each wheel at the normal front / rear wheel distribution ratio without controlling the front / rear wheel distribution ratio. This prevents the increase in the yaw rate in the turning direction of the vehicle from being hindered and reflects the driver's intention to promote turning.
[0056]
The electronic control unit 90 controls the left and right wheels to the target braking pressure by controlling only the control valve 22F or 22R when the left and right wheels have the same target braking pressure. When the target braking pressures of the left and right wheels are different from each other, the target upstream pressure is set to the higher target braking pressure of the left and right wheels, and the braking pressure Pi of the wheel with the higher target braking pressure Pti of the left and right wheels is set to the control valve 22F or The upstream pressure is controlled by 22R to be controlled to the target upstream pressure Ptf or Ptr, and the braking pressure of the left and right wheels is controlled to the corresponding target braking pressure by the corresponding pressure increasing valve and the pressure reducing valve.
[0057]
Further, the electronic control unit 90 determines whether or not the master cylinder pressure Pm is equal to or higher than the target braking pressure of the wheel in a situation where the braking pressure of the wheel having the higher target braking pressure is to be reduced. When the master cylinder pressure Pm is lower than the target braking pressure of the wheel, the control valve 22F or 22R is controlled, in other words, the oil in the brake hydraulic control conduits 18F and 18R between the control valve and the pump is controlled. By discharging to the connection conduits 54F and 54R through the valve, the upstream pressure and the pressure in the wheel cylinder are controlled to the target braking pressure.
[0058]
On the other hand, when the master cylinder pressure Pm is equal to or higher than the target braking pressure of the wheel, the electronic control unit 90 controls the opening / closing of the pressure reducing valve while the pressure increasing valve is opened, so that the wheel cylinder to be pressure reduced. The oil inside is discharged to the buffer reservoirs 38F, 38R via the brake hydraulic pressure control conduit 20FL and the like and the connection conduits 36F, 36R, thereby reducing the pressure in the wheel cylinder to the target braking pressure.
[0059]
Next, a braking control routine at the time of turning braking in the illustrated embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 3 is started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.
[0060]
First, at step 10, a signal indicating the master cylinder pressure Pm detected by the pressure sensor 96 is read, and at step 20, the master cylinder pressure Pm is set in a manner known in the art. Based on this, the target braking pressure Pti of each wheel is calculated, and when anti-skid control is required, the target braking pressure Pti necessary to reduce excessive braking slip of the wheel is calculated. Although not shown in FIG. 3, when the control is started, the electromagnetic on-off valves 60F and 60R are opened, and the driving of the oil pumps 42F and 42R is started.
[0061]
In step 30, it is determined whether or not the flag Fus is 0, that is, whether or not the vehicle is in an understeer state and additional steering is performed by the driver, in other words, whether or not the driver intends to promote turning. When a negative determination is made, the process proceeds to step 130. When a negative determination is made, the process proceeds to step 40.
[0062]
In step 40, it is determined whether or not the front / rear wheel distribution control of the braking force during the turning braking of the vehicle is permitted according to the routine shown in FIG. When the determination is made, the routine proceeds to step 130, and when the determination is affirmative, the routine proceeds to step 50.
[0063]
In step 50, the product Gy × V of the lateral acceleration Gy of the vehicle and the vehicle speed V is calculated, and whether the absolute value of the product Gy × V is greater than or equal to the first reference value Th1 (positive constant). If a negative determination is made, the process proceeds to step 130. If an affirmative determination is made, the process proceeds to step 60.
[0064]
In step 60, it is determined whether or not the absolute value of the product Gy × V is equal to or greater than a second reference value Th2 (a positive constant greater than Th1). If a negative determination is made, step 80 is performed. If the determination is affirmative, the turning direction of the vehicle is determined in step 70 based on the steering angle θ, etc., and the target braking pressure Pti (i = rl or rr) for the rear wheels on the turning side is set to zero. Is set.
[0065]
In step 80, the amount of increase A of the front wheel braking pressure is calculated from the map corresponding to the graph shown in FIG. 6 based on the absolute value of the product Gy × V. In step 90, the master cylinder pressure Pm is calculated. Based on the map corresponding to the graph shown in FIG. 7, a correction coefficient Kpf is calculated, and in step 100, the increase amount A of the front wheel braking pressure is corrected to the product of the correction coefficient Kpf and the increase amount A. Thus, the corrected front wheel braking pressure increase amount A ′ is calculated.
[0066]
In step 110, the target braking pressures Ptfl and Ptfr for the left and right front wheels are corrected by adding the corrected pressure increase amount A 'to them, and in step 120, the routine shown in FIG. The flag Fus is controlled as will be described later.
[0067]
In step 130, the reference value θc for determining whether or not additional steering by the driver, that is, whether or not the steering wheel has been increased, is set to the current steering angle θ, and, for example, according to the same equation as the above equation 1 A reference yaw rate Yrt of the vehicle is calculated and a yaw rate deviation ΔYr (= Yrt−Yr) is calculated as a difference between the reference yaw rate Yrt of the vehicle and the actual yaw rate Yr. In step 140, the braking pressure of each wheel is calculated. The control valves 22F and 22R are controlled so as to reach the target braking pressure Pti, and the electromagnetic on-off valve 34RL or 34RR is opened as necessary, whereby the braking force of each wheel is controlled to a value corresponding to the target braking pressure Pti. Then, return to Step 10.
[0068]
In step 41 of the control permission determination routine shown in FIG. 4, it is determined whether or not the master cylinder pressure Pm is greater than or equal to a reference value Pmo (a positive constant smaller than the first reference value Th1). If a negative determination is made, the process proceeds to step 43. If an affirmative determination is made, it is determined in step 42 whether or not the stop lamp switch 106 is in an on state, and a negative determination is made. Sometimes, the process proceeds to step 48, and when an affirmative determination is made, the process proceeds to step 43.
[0069]
In step 43, it is determined whether or not the left front wheel is in anti-skid control and the right front wheel is not in anti-skid control. If an affirmative determination is made, the process proceeds to step 48 to make a negative determination. If yes, go to step 44. In step 44, it is determined whether or not the right front wheel is in anti-skid control and the left front wheel is not in anti-skid control. If an affirmative determination is made, the process proceeds to step 48 to make a negative determination. If yes, go to step 45.
[0070]
In step 45, the steering angle θ is not less than the reference value θo (positive constant), the vehicle yaw rate Yr is not less than the reference value Yro (positive constant), and the vehicle lateral acceleration Gy is the reference value Gyo (positive). If the determination is affirmative, the process proceeds to step 47. If the determination is negative, the process proceeds to step 46. In step 46, it is determined whether or not the steering angle θ is equal to or less than the reference value −θo, the yaw rate Yr of the vehicle is equal to or less than the reference value −Yro, and the lateral acceleration Gy of the vehicle is equal to or less than −Gyo. When an affirmative determination is made, a determination is made at step 47 that the front / rear wheel distribution control of the braking force at the time of turning braking of the vehicle is permitted, and when a negative determination is made, step 48 is performed. In this case, it is determined that the front / rear wheel distribution control of the braking force is not permitted.
[0071]
As can be understood from the above description, in steps 41 and 42, it is determined whether or not a braking operation is being performed by the driver. In steps 43 and 44, the left and right friction coefficients of the road surface are greatly different. It is determined whether or not the road is a so-called straddle, and in steps 45 and 46, it is determined whether or not the vehicle is in a turning state. Therefore, the vehicle is in a turning braking state and the road surface is straddling. If this is not the case, the front and rear wheel distribution control of the braking force is permitted. It should be noted that if an affirmative determination is made in both steps 41 and 42, it is determined that the braking operation by the driver is being performed, and the process may be modified to proceed to step 43.
[0072]
In step 121 of the flag Fus control routine shown in FIG. 5, it is determined whether or not the vehicle is in a left turn state in a manner known in the art, and a negative determination is made. If YES, the process proceeds to step 124. If an affirmative determination is made, the process proceeds to step 122.
[0073]
In step 122, ΔYro is set as a positive constant, and it is determined whether the yaw rate deviation ΔYr exceeds the reference value ΔYro, that is, whether the vehicle is in an understeer state, and a negative determination is made. If YES in step 127, the flow advances to step 127. If an affirmative determination is made, the flow advances to step 123.
[0074]
In step 123, it is determined whether or not the steering angle θ exceeds the reference value θc, that is, whether or not the driver has increased the steering wheel in the left turn direction. If NO is determined, the process proceeds to step 126. If a negative determination is made, the process proceeds to step 127.
[0075]
In step 124, it is determined whether or not the yaw rate deviation ΔYr is less than the reference value −ΔYro, that is, whether or not the vehicle is in an understeer state. If a negative determination is made, the process proceeds to step 127. If an affirmative determination is made, the routine proceeds to step 125.
[0076]
In step 125, it is determined whether or not the steering angle θ is less than the reference value θc, that is, whether or not the driver has turned the steering wheel in the right turn direction. When the determination is made, the flag Fus is set to 1 at step 126, and when the negative determination is made, the flag Fus is reset to 0 at step 127.
[0077]
Thus, according to the illustrated embodiment, in step 20, the target braking pressure Pti of each wheel is calculated based on the braking operation amount (master cylinder pressure Pm) of the driver, and in step 50, the lateral acceleration Gy of the vehicle is calculated. When the absolute value of the product Gy × V is greater than or equal to the first reference value Th1 and less than the second reference value Th2, an affirmative determination is made in steps 50 and 60, respectively. Determination and negative determination are performed, and in steps 80 to 100, the pressure increase amount A ′ of the front wheel is calculated so as to increase as the absolute value of the product Gy × V increases, and thereby the size of the product Gy × V increases. The braking pressure of the front wheels is increased so as to increase.
[0078]
Accordingly, the larger the product Gy × V is, the more the front-rear wheel distribution ratio of the braking force becomes closer to the front wheels, so that the vehicle yaw rate can be prevented from increasing in the turning direction, and the vehicle can be braked and turned stably. Also, since the braking force of the front wheels is increased instead of reducing the braking force of the rear wheels, it is possible to surely prevent the deceleration of the vehicle from being lowered, thereby reducing the deceleration of the vehicle. This can surely prevent the driver from feeling uncomfortable or dissatisfied.
[0079]
Although the braking force of the entire vehicle increases due to the increase of the braking force of the front wheels, if the deceleration of the vehicle becomes too high due to this, the driver reduces the amount of depression of the brake pedal and the braking force of the entire vehicle. Therefore, the increase in the braking force of the front wheels does not prevent the driver from achieving the vehicle deceleration desired by the driver.
[0080]
Further, according to the illustrated embodiment, in step 30, it is determined whether or not the flag Fus is 0, that is, whether or not there is a driver's intention to promote turning. When it is determined that there is no braking, the braking force front / rear wheel distribution control in steps 40 to 110 is executed, but when it is determined that the driver is willing to promote turning, the processing of step 130 is performed. Then, the process proceeds directly to step 140, whereby the braking force front / rear wheel distribution control in steps 40 to 110 is not executed, and the braking force of each wheel becomes a value corresponding to the target braking pressure Pti calculated in step 20. Be controlled.
[0081]
Therefore, when the driver turns the steering wheel during turning braking of the vehicle and tries to turn the vehicle beyond the current level, the front and rear wheel distribution control in steps 40 to 110 is executed, and the front and rear distribution of the braking force is reduced. It is possible to reliably prevent the driver's intention to promote turning from being reflected due to being controlled closer to the front wheels.
[0082]
In particular, according to the illustrated embodiment, it is determined whether or not the driver has a willingness to turn, in steps 121 to 127, whether or not the vehicle is understeered and additional steering is performed by the driver. Therefore, the presence / absence of the driver's intention to promote turning is compared to the case where the determination of whether or not the driver has the intention to promote turning is performed only by determining whether or not additional steering is performed by the driver. That is, it is possible to accurately determine whether or not the vehicle is going to turn more than the current state.
[0083]
Further, according to the illustrated embodiment, when the absolute value of the product Gy × V is equal to or larger than the second reference value Th2, an affirmative determination is made in steps 50 and 60, and the product is determined in steps 80 to 110. The front wheel pressure increase amount A ′ is calculated so as to increase as the absolute value of Gy × V increases, thereby increasing the brake pressure of the front wheel so as to increase as the product Gy × V increases. At 70, the target braking pressure for the rear inner wheel is set to 0, and at step 140, the pressure reducing valve 34RL or 34RR is opened, so that the braking pressure for the rear inner wheel is fully reduced. The braking force of the wheel is reduced.
[0084]
Therefore, when the absolute value of the product Gy × V is greater than or equal to the second reference value Th2, that is, in a situation where the yaw rate of the vehicle is likely to increase further, the absolute value of the product Gy × V is greater than or equal to the first reference value Th1. Compared to the case where it is less than the second reference value Th2, the front-rear wheel distribution ratio of the braking force is even closer to the front wheels, so the vehicle yaw rate is prevented from increasing in the turning direction and the vehicle is stabilized. The braking force of the front wheel is increased and the braking force of the rear wheel is reduced, so that the braking force of the entire vehicle becomes excessive and the deceleration of the vehicle becomes excessive. It can be surely prevented.
[0085]
Further, according to the illustrated embodiment, in step 90, the correction coefficient Kpf is calculated so as to decrease as the master cylinder pressure Pm increases. In step 100, the increase amount A of the front wheel braking pressure is increased with the correction coefficient Kpf. Since the amount of braking operation by the driver is high and the braking force of the wheel by the driver's braking operation is high, the front wheel braking pressure is increased, so that the front wheel braking pressure is increased. It is possible to reliably reduce the possibility that the turning performance of the vehicle will deteriorate due to excessive braking force and a decrease in lateral force of the front wheels.
[0086]
Further, according to the illustrated embodiment, since only the braking pressure of the rear inner wheel is reduced in step 70, the deceleration of the vehicle is lower than when the braking pressure of the left and right rear wheels is reduced. The fear can be reduced, and an anti-spin moment due to the difference in braking force between the left and right rear wheels can be applied to the vehicle, thereby effectively reducing the possibility that the vehicle will be in a spin state.
[0087]
In the illustrated embodiment, the target braking pressure of the turning inner rear wheel is set to 0 in step 70. In the illustrated braking device, the electromagnetic on-off valves 34RL and 34RR for pressure reduction are intermittently connected. This is because if the braking pressure of the rear wheels is reduced by opening and closing automatically, abnormal noise is likely to occur due to the intermittent opening and closing.
[0088]
Further, according to the illustrated embodiment, when the absolute value of the product Gy × V is equal to or larger than the second reference value Th2, the absolute value of the product Gy × V is smaller than the second reference value, Since the rate of increase of the pressure increase amount A with respect to the absolute value of the product Gy × V is small, the braking force of the front wheel becomes excessive and the lateral force of the front wheel becomes excessive in a region where the product Gy × V is larger than the second reference value Th2. It is possible to reduce the possibility that the turning performance of the vehicle will deteriorate due to the decrease.
[0089]
Further, according to the illustrated embodiment, in step 40, it is determined whether or not the front and rear wheel distribution control of the braking force is permitted, the braking operation by the driver is performed, and the road surface is Since each step after step 50 is executed only when the vehicle is not on a fork road and is in a turning state, the front and rear wheel distribution of the braking force is unnecessarily performed as compared with the case where the permission determination at step 40 is not performed. The possibility that control will be performed can be reduced reliably. Especially when the road surface is a straddling road, the braking force front / rear wheel distribution control is not performed, so the braking force in a situation where the road surface is a straddling road It is possible to reliably prevent the behavior of the vehicle from deteriorating due to the execution of the front and rear wheel distribution control.
[0090]
Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.
[0091]
For example, in the illustrated embodiment, when the driver is willing to turn, the front / rear wheel distribution control of the braking force in steps 40 to 110 is not executed, and the braking force of each wheel is calculated in step 20. By controlling to a value corresponding to the target braking pressure Pti, in other words, by setting the control amount of the front and rear wheel distribution control of the braking force to 0, the driver's intention to promote turning is reliably reflected. However, when the driver intends to promote turning, the control amount of the front and rear wheel distribution control of the braking force is reduced, and the front and rear wheel distribution control of the braking force is executed with the reduced control amount. Thus, the driver's intention to promote turning may be reflected as much as possible.
[0092]
Also, in this case, for example, the yaw rate deviation ΔYr is increased so that the amount of reduction in the control amount of the front and rear wheel distribution control of the braking force increases as the driver's willingness to promote turning increases or as the driver's steering speed increases. The change rate, the magnitude of the additional steering amount (θ−θc), the change rate, the steering angular velocity, and the like may be variably set.
[0093]
Further, in the illustrated embodiment, at least the braking force of the front wheels is increased so that the distribution ratio of the braking force is controlled closer to the front wheels. The braking force may be applied to a vehicle in which the distribution ratio of the braking force is controlled closer to the front wheel, and the front wheel is the steering wheel. However, the braking control device of the present invention uses the steering wheel as the rear wheel. It may be applied to a certain vehicle, and in that case, when the driver has a willingness to turn, the steering force distribution ratio is controlled closer to the front wheels than when there is no turning promotion intention. It is comprised so that the braking force of the rear wheel which is a wheel may be reduced.
[0094]
Further, in the illustrated embodiment, whether or not the driver is willing to turn is determined by determining whether or not the vehicle is understeered and additional steering is performed by the driver. Whether or not the vehicle is understeered is determined based on the yaw rate deviation ΔYr and the deviation between the vehicle standard yaw rate Yrt and the actual yaw rate Yr. May be modified.
[0095]
In the illustrated embodiment, the braking device controls the control valve 22F or 22R when the left and right wheels have the same target braking pressure, and controls when the left and right wheels have different target braking pressures. In addition to the valve, the electromagnetic on-off valves 28FL to 28RR as pressure increasing valves or the electromagnetic on-off valves 34FL to 34RR as pressure reducing valves are controlled by a hydraulic braking device. The braking device to which the braking control device of the present invention is applied. As long as the braking force of each wheel can be individually controlled to the target braking force, it may be a hydraulic braking device or an electrical braking device having any configuration known in the art.
[0096]
In the illustrated embodiment, when the absolute value of the product of the lateral acceleration Gy of the vehicle and the vehicle speed V is equal to or greater than the second reference value Th2, the target braking pressure for the rear wheel on the inside of the turn is set to zero. However, when the braking device is configured to continuously increase or decrease the braking pressure of each wheel, in step 70, the vehicle is determined from the map corresponding to the graph shown in FIG. Based on the absolute value of the product of the lateral acceleration Gy and the vehicle speed V, the pressure reduction amount B of the rear inner wheel is calculated. In step 110, the target braking pressure of the left and right front wheels is corrected to increase by the pressure increase amount A ', The wheel target braking pressure may be modified so that the pressure reduction amount B is reduced. In step 70, the product of the vehicle lateral acceleration Gy and the vehicle speed V is calculated from the map corresponding to the graph shown in FIG. Based on the absolute value, depressurization amount B of the turning inner rear wheel and the turning outer rear wheel The pressure amount Ar is calculated, and in step 110, the target braking pressure of the left and right front wheels is corrected to increase in the pressure increase amount A ', the target braking pressure of the rear inner wheel is corrected to decrease in the decrease amount B, and the target of the rear outer wheel is turned. The braking pressure may be corrected so that the pressure increase amount Ar is corrected to increase.
[0097]
According to these modified examples, when the product of the lateral acceleration Gy and the vehicle speed V of the vehicle changes before and after the second reference value Th2, it is possible to prevent the braking force of the entire vehicle from changing greatly, thereby turning the vehicle. The stability of the vehicle during braking can be further improved as compared with the case of the above-described embodiment. In these modified examples, the second reference value Th2 may be set to the same value as the first reference value Th1.
[0098]
In the illustrated embodiment, the control valve 22F, 22R and the electromagnetic on-off valve as the pressure increasing valve or the electromagnetic on-off valve as the pressure reducing valve are controlled in step 140, whereby the braking pressure of each wheel is set to the target braking. However, the pressure of the wheel cylinders 22FL to 26RR of each wheel may be detected and the braking pressure of each wheel may be corrected to be controlled in a feedback manner.
[0099]
In the illustrated embodiment, the target braking pressure Pti of each wheel is calculated based on the braking operation amount of the driver or for reducing the braking slip of the wheel for the purpose of anti-skid control. However, the target braking pressure Pti may be calculated for the purpose of any vehicle control known in the art, such as behavior control or traction control of a braking force control type vehicle.
[0100]
In the illustrated embodiment, each valve is set to the control position even when the driver does not perform the braking operation, but it is not necessary to control the braking pressure of the wheels. Sometimes, each valve may be modified to be set to the non-control position shown in FIG.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a hydraulic circuit and an electronic control device of one embodiment of a braking control device according to the present invention.
FIG. 2 is an illustrative sectional view showing a front-wheel control valve shown in FIG. 1;
FIG. 3 is a flowchart showing a braking control routine in the illustrated embodiment.
FIG. 4 is a flowchart showing a permission determination routine for braking force front and rear wheel distribution control executed in step 40 of FIG. 3;
FIG. 5 is a flowchart showing a flag Fus control routine executed in step 120 of FIG. 3;
FIG. 6 is a graph showing a relationship between an absolute value of a product Gy × V of a lateral acceleration Gy and a vehicle speed V of a vehicle and a braking pressure increase amount A of a front wheel.
FIG. 7 is a graph showing a relationship between a master cylinder pressure Pm and a correction coefficient Kpf.
FIG. 8 is a graph showing the relationship between the absolute value of the product Gy × V of the lateral acceleration Gy and the vehicle speed V of the vehicle and the pressure reduction amount B of the turning inner rear wheel and the pressure increasing amount Ar of the turning outer rear wheel.
[Explanation of symbols]
10 ... Brake device
14 ... Master cylinder
22F, 22R ... Control valve
26FL, 26FR, 26RL, 26RR ... Wheel cylinder
42F, 42R ... Oil pump
28FL-28RR, 34FL-34RR ... Open / close valve
42F, 42R ... Pump
48F, 48R ... Damper
90 ... Electronic control unit
96 ... Pressure sensor
98 ... Lateral acceleration sensor
100 ... Yaw rate sensor
102 ... Steering angle sensor
104: Vehicle speed sensor
106 ... Stop lamp switch (STPSW)

Claims (4)

A vehicle braking control device that performs braking force distribution adjustment control of the front and rear wheels based on the state of the vehicle at the time of vehicle turning braking is provided with a determination unit that determines whether or not the driver intends to promote turning. When the driver is in an understeer state and additional steering is performed by the driver, it is determined that the driver has a willingness to promote turning, and when the determining means determines that the driver has a willingness to promote turning, the braking force of the steered wheels Is lower than the value of the front and rear wheel braking force distribution adjustment control, and the front and rear wheel braking force distribution adjustment control increases the braking force of the front wheel relative to the rear wheel as the product of the lateral acceleration of the vehicle and the vehicle speed increases. A vehicle braking control device that controls the distribution ratio so that the distribution ratio becomes high . A vehicle braking control apparatus that performs braking force distribution adjustment control of front and rear wheels based on the vehicle state during turning braking of the vehicle is provided with means for determining whether or not the driver is willing to promote turning. When it is determined that there is, the braking force of the steering wheel is made lower than the value of the braking force distribution adjustment control of the front and rear wheels, and the braking force distribution adjustment control of the front and rear wheels is the magnitude of the product of the lateral acceleration of the vehicle and the vehicle speed. The vehicle braking control device is characterized in that the distribution ratio is controlled so that the distribution ratio of the braking force of the front wheels to the rear wheels becomes higher as the vehicle speed increases. According to claim 1 or 2, characterized in that to control the braking force of at least one wheel so that the distribution ratio of the front wheel braking force to the rear wheel becomes higher braking force distribution adjustment control of the front and rear wheels A braking control device for a vehicle. 4. The vehicle braking control device according to claim 3 , wherein the steering wheel is a front wheel, and the braking force of the front wheel is lowered by reducing a control amount of the braking force distribution adjustment control of the front and rear wheels.

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