JP2002211374A - Braking controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control braking force of wheels by the optimum braking force control means is accordance with a braking condition of the wheels in a vehicle having a plurality of braking force control means controlling braking forces of the wheels and having different response properties. SOLUTION: A target braking pressure Pti and a target slip rate SLti of the wheels are computer (S20). As for the wheel having a higher target braking pressure out of right and left wheels of the same system, if a braking force generation region of the wheel is a linear region, a pressure (upstream pressure) between a control valve and a pump 42F is controlled to the target braking pressure by controlling the control valve 22F, a pressure intensifying control valve, and a pressure reducing control valve so that the braking pressures of the wheels are controlled to the target braking pressure (S70 to S105, S110 or S160). If the braking force generation region of the wheel is a non-linear region, pressure intensification and reduction control is performed by the pressure intensifying valve and the pressure reducing valve to control the braking forces so that actual slip rate of the wheels becomes the target slip rate (S80).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field 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 a vehicle having a plurality of braking force control means having different responsiveness for controlling the braking force of wheels. According to.

[0002]

2. Description of the Related Art As one of brake control devices for vehicles such as automobiles, for example, Japanese Patent Application Laid-Open No. 2000-2000 filed by the present applicant.
As described in JP-A-190635, means for calculating a target braking force and a target slip ratio of each wheel according to a vehicle state or a braking operation by a driver, and a relationship between the braking force and the braking pressure in a linear region. Control means for controlling the braking pressure of each wheel based on a target braking force, and control switching means for controlling the braking pressure of each wheel based on a target slip ratio in a region where the relationship is non-linear. The apparatus has means for estimating the actual slip rate of each wheel, and the control switching means controls the wheel based on the target slip rate rather than the control based on the target braking force when the actual slip rate of the wheel exceeds a reference value. 2. Description of the Related Art A vehicular braking control device characterized by switching to (i) is conventionally known.

[0003] According to the braking control device according to the above proposal, control based on the target braking force is performed when the wheel is in the linear region, and control based on the target slip ratio is performed when the wheel is in the non-linear region. The braking control is performed with high accuracy in accordance with the condition of the wheels, whereby the motion of the vehicle can be controlled with high accuracy, and the motion of the vehicle can be reliably and appropriately stabilized.

[0004]

However, in the braking control apparatus according to the above-mentioned proposal, the responsiveness of the braking force control means for controlling the braking force of the wheels is not taken into consideration. Does not consider how to control the braking force of the wheels in a vehicle having a plurality of different braking force control means, and thus there is room for improvement in this respect. Further, in the above-described braking control device according to the above proposal, it is complicated to determine whether the relationship of the braking force to the braking pressure is in a linear region or a non-linear region. There is a problem that the control device is expensive, and there is still room for improvement in this respect.

In the present invention, the braking pressure of each wheel is controlled based on the target braking force in a region where the relationship between the braking pressure and the braking force is linear, and the target slip ratio is controlled in a region where the relationship is nonlinear. The present invention has been made in view of the above-described problems in the brake control device according to the above-mentioned proposal, which is configured to control the braking pressure of each wheel based on the above-described problem. In a vehicle having a plurality of braking force control units having different responsiveness to be controlled, the most suitable braking force control unit controls the braking force of the wheels according to the braking condition of the wheels.

A secondary object of the present invention is to achieve the above-mentioned main object and to determine whether or not the braking force generation region is a non-linear region more easily and more easily than in the past. It is.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned main object is achieved by the structure of claim 1, that is, a plurality of braking force control means having different responsiveness for controlling the braking force of the wheel; Braking force generation area determining means for determining whether the braking force generation area is a non-linear area; and controlling the braking force by the plurality of braking force control means in accordance with the determination result of the braking force generation area determining means. Selection control means for selecting the braking force control means to be used and controlling the braking force of the wheels using the selected braking force control means.

According to the first aspect of the present invention, it is determined whether or not the braking force generation region of the wheel is a non-linear region. The braking force control means used for controlling the braking force is selected from the braking force control means, and the braking force of the wheel is controlled using the selected braking force control means. The braking force of the wheel is controlled by the optimal braking force control means according to the result of the determination as to whether or not the area is the area.

According to the present invention, in order to achieve the above-mentioned main object effectively and to achieve the above-mentioned sub-object, in the structure of the above-mentioned claim 1, the braking force generation area determination is made. The means includes means for detecting wheel speed and means for calculating wheel acceleration based on the detected wheel speed, and determines that the braking force generation region is a non-linear region when the wheel acceleration is less than a reference value. (The configuration of claim 2).

In general, when the braking force generation region of a wheel is a linear region, the control amount for the braking force control means and the braking force actually generated by the wheel are substantially proportional to each other. Although the ratio of the power and the ratio of the wheel slip ratio to the braking force are substantially constant, when the braking force generation region of the wheel shifts from the linear region to the non-linear region due to the increase of the control amount, the ratio of the braking force to the control amount Decreases, and conversely, the ratio of the slip ratio to the braking force increases, and the wheel acceleration correspondingly decreases. Therefore, it can be determined whether or not the braking force generation region is a non-linear region based on the wheel acceleration when the wheel is braked.

According to the second aspect of the present invention, the wheel speed is detected, the wheel acceleration is calculated based on the detected wheel speed, and when the wheel acceleration is less than the reference value, the braking force generation region is a non-linear region. Since it is determined that there is, it is possible to determine whether or not the braking force generation region of the wheel is a non-linear region without requiring a complicated calculation or an expensive control device.

According to the present invention, in order to effectively achieve the above-mentioned main object, the vehicle according to the first or second aspect is provided with a hydraulic pressure of the master cylinder corresponding to the wheels. A hydraulic fluid supply passage for supplying to the wheel cylinder, a control valve provided in the hydraulic fluid supply passage, and constituting a first braking force control means, and a valve disposed between the control valve and the wheel cylinder. A pressure increasing / decreasing valve provided in a hydraulic pressure supply passage and constituting second braking force control means; and a high pressure liquid supply for supplying a high pressure hydraulic liquid to the hydraulic pressure supply passage between the control valve and the pressure increasing / decreasing valve. And the selection control means controls the control valve when the braking force generation area is determined to be a linear area by the braking force generation area determination means, thereby controlling the control valve and the wheel cylinder. Between The braking force of the wheels is controlled by controlling the pressure in the working hydraulic pressure supply passage, and when the braking force generation region is determined to be a non-linear region by the braking force generation region determining means, the pressure increasing / decreasing valve is controlled. To control the braking force of the wheels.
Configuration).

In general, the responsiveness of the braking pressure control by the pressure increasing / decreasing valve in the above configuration is higher than the responsiveness of the braking pressure control by the control valve. It is preferable that the braking pressure is controlled by the pressure increasing / decreasing valve when high response is required, and it is preferable that the braking pressure is controlled by the control valve when high response is not required.

According to the third aspect of the present invention, when it is determined that the braking force generation region is a linear region, the control valve is controlled to control the hydraulic fluid supply passage between the control valve and the wheel cylinder. The braking force of the wheels is controlled by controlling the internal pressure, and when it is determined that the braking force generation region is a nonlinear region, the braking force of the wheels is controlled by controlling the pressure increasing / decreasing valve. When the braking force generation region is a linear region and high response is not required, the braking pressure is controlled by the control valve. When the braking force generation region is a non-linear region and high response is required, the braking pressure is controlled by the pressure increasing / decreasing valve.

According to the present invention, in order to effectively achieve the above-mentioned main object, in the configuration of the third aspect, the selection control means includes means for calculating a target braking pressure and a target slip ratio. When the braking force generation area is determined to be a linear area by the braking force generation area determination means,
The control valve is controlled so that the pressure in the hydraulic fluid supply passage becomes the target braking pressure, and when the braking force generation region is determined to be in the non-linear region by the braking force generation region determining means, the wheel slips. The pressure increasing / reducing valve is controlled so that the rate becomes the target slip rate (the configuration of claim 4).

In general, when the braking force generation region of a wheel is a linear region, the braking pressure is substantially proportional to the braking force actually generated by the wheel. Preferably, when the braking force generation region of the wheel is a non-linear region, the braking pressure is not proportional to the braking force actually generated by the wheel, and the slip ratio changes with respect to the braking force change amount. Therefore, it is preferable that the response is controlled so that the slip ratio of the wheel becomes the target slip ratio.

According to the fourth aspect of the present invention, when it is determined that the braking force generation region is a linear region, the control valve is controlled so that the pressure in the hydraulic fluid supply passage becomes the target braking pressure, and the control valve is controlled. When it is determined that the power generation region is a non-linear region, the pressure increasing / decreasing valve is controlled so that the slip ratio of the wheel becomes the target slip ratio. Therefore, when the braking force generation region is in the linear region and when the braking force generation region is non-linear. In any case in the range, the optimal braking force control means is selected, and the selected braking force control means is optimally controlled.

[0018]

According to a preferred aspect of the present invention, in the configuration of the first aspect, the plurality of braking force control means are relatively low-responsive braking force control means. When the braking force generation region determining unit determines that the braking force generation region is a linear region, the selection control unit switches the braking force control unit with the lower response to the braking force control unit. When the braking force generation area is determined to be a non-linear area by the braking force generation area determination means, a braking force control means having higher responsiveness is selected (preferred mode 1).

According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 1, the selection control means has a means for calculating a target braking pressure and a target slip ratio, and determines the braking force generation area. When the braking force generation region is determined to be a linear region by the means, the braking force control region having a lower response is controlled based on the target braking pressure, and the braking force generation region is determined to be a non-linear region by the braking force generation region determination device. When it is determined that the braking force is higher, the braking force control unit having the higher responsiveness is controlled based on the target slip ratio (preferred mode 2).

According to a preferred aspect of the present invention, in the configuration of the third aspect, the control valve is configured such that a pressure in a hydraulic fluid supply passage between the control valve and the wheel cylinder is higher than a target braking pressure. When the pressure is too high, the valve opens automatically to guide the hydraulic fluid in the hydraulic fluid supply passage between the control valve and the wheel cylinder to the master cylinder through the control valve, thereby supplying hydraulic fluid pressure to the wheel cylinder. It is configured to control the pressure in the passage to the target braking pressure (preferred mode 3).

According to another preferred embodiment of the present invention, in the configuration of the second aspect, the hydraulic fluid supply passage is provided with hydraulic fluid pressure of the master cylinder corresponding to each wheel of the same system. The pressure increasing / decreasing valve is provided in the working fluid pressure supply passage corresponding to each wheel and configured to increase / decrease the pressure in the corresponding wheel cylinder (preferred mode 4).

According to another preferred embodiment of the present invention, in the configuration of the above-mentioned preferred embodiment 4, the selection control means secures a stable running of the vehicle as required irrespective of a driver's braking operation amount. It is configured to calculate a target braking pressure and a target slip ratio corresponding to the wheel braking force required to perform the operation (preferred mode 5).

According to another preferred embodiment of the present invention, in the configuration of the above-mentioned preferred embodiment 5, the selection control means includes a braking force generation region for a wheel having the highest target braking pressure among wheels of the same system. When the determining means determines that the braking force generation area of the wheel is a linear area, the control valve is controlled so that the pressure in the hydraulic fluid supply passage becomes the target braking pressure, and the braking force generation area determining means determines When it is determined that the braking force generation area is a non-linear area, the pressure increasing / decreasing valve is controlled so that the wheel slip rate becomes the target slip rate, and the pressure increasing / decreasing valve is controlled so that the wheel slip rate becomes the target slip rate for the other wheels. (Preferred mode 6).

According to another preferred embodiment of the present invention, in the configuration of the above-mentioned preferred embodiment 5, the selection control means includes a braking force generation region for a wheel having the highest target braking pressure among wheels of the same system. When the determining means determines that the braking force generation area is a linear area, the control valve is controlled such that the pressure in the hydraulic fluid supply passage becomes the target braking pressure,
When the braking force generation area is determined to be a non-linear area by the braking force generation area determination means, the pressure increasing / decreasing valve is controlled so that the wheel slip rate becomes the target slip rate. The pressure increasing / decreasing valve is configured to be controlled to the braking pressure (preferred mode 7).

According to another preferred embodiment of the present invention, in the configuration of the above-mentioned preferred embodiment 4, the high-pressure liquid supply source includes a reservoir for storing the hydraulic fluid, and a pump for pumping the hydraulic fluid from the reservoir and discharging the hydraulic fluid. And a pump suction valve for controlling communication between a working fluid pressure supply passage between the master cylinder and the control valve and a passage connecting the suction side of the pump (preferred mode 8).

According to another preferred embodiment of the present invention, in the configuration of the above-mentioned preferred embodiment 7, the selection control means determines that the target braking pressure is lower than the pressure in the wheel cylinder and the operating fluid pressure of the master cylinder is lower. When the pressure is equal to or higher than the target braking pressure, the pressure in the wheel cylinder is increased or decreased by the pressure increasing / decreasing valve (preferred mode 9).

According to another preferred embodiment of the present invention, in the configuration of the above-mentioned preferred embodiment 9, the selection control means closes the pump suction valve when the pressure in the wheel cylinder is reduced by the pressure increasing / reducing valve. It is configured to be valved (preferred embodiment 10).

According to another preferred aspect of the present invention, in the configuration of the fourth aspect, the selection control means secures a stable running of the vehicle as required irrespective of the driver's braking operation amount. It is configured to calculate a target braking pressure and a target slip ratio corresponding to the wheel braking force necessary for performing this operation (preferred mode 11).

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing a hydraulic circuit and an electronic control device of one embodiment of a brake control device according to the present invention, and FIG. 2 is an exploded cross-sectional view showing a control valve for a front wheel shown in FIG. FIG. In FIG. 1, the solenoids of the electromagnetically driven valves are not shown.

In FIG. 1, reference numeral 10 denotes a hydraulic braking device. The braking device 10 has a master cylinder 14 for pumping brake oil in response to a driver's depressing operation of a brake pedal 12. I have. Master cylinder 1
Reference numeral 4 has a first master cylinder chamber 14A and a second master cylinder chamber 14B defined by a free piston 16 urged to a predetermined position by compression coil springs on both sides thereof.

One end of a brake hydraulic control conduit 18F for the front wheel is connected to the first master cylinder chamber 14A, and the other end of the brake hydraulic control conduit 18F is connected to a brake hydraulic control conduit 20FL for the left front wheel and a right front wheel. One end of the brake hydraulic control conduit 20FR is connected. A control valve 22F for the front wheels, which is a normally-open electromagnetic on-off valve, is provided in the middle of the brake hydraulic pressure control conduit 18F. A check bypass conduit 24F that allows only oil flow from the first master cylinder chamber 14A to the brake hydraulic control conduit 20FL or the brake hydraulic control conduit 20FR is connected to the brake hydraulic control conduit 18F on both sides of the control valve 22F. .

As schematically shown in FIG. 2, the control valve 22F has a housing 72 inside which a valve chamber 70 is defined, and a valve element 74 is arranged in the valve chamber 70 so as to be able to reciprocate. ing. A portion 18FA of the brake oil pressure control conduit 18F on the master cylinder 14 side is always connected to the valve chamber 70 through an internal passage 76.
A portion 18FB of the 8F on the opposite side to the master cylinder 14 is connected through an internal passage 78 and a port 80 for communication.

As shown, a solenoid 82 is disposed around the valve element 74, and the valve element 74 is urged by a compression coil spring 84 to the valve opening position shown in FIG. When a drive voltage is applied to the solenoid 82, the valve element 74 resists the spring force of the compression coil spring 84 and the port 80.
To close the valve by closing the port 80.

When the control valve 22F is in the closed position, the sum of the force due to the pressure in the portion 18FB of the brake oil pressure control conduit 18F on the side opposite to the master cylinder 14 and the spring force of the compression coil spring 84. When the pressure becomes higher than the electromagnetic force generated by the solenoid 82, the valve element 74 opens the port away from the port 80, and the oil in the portion 18FB flows through the internal passage 78, the port 80, the valve chamber 70, and the internal passage 76 to control the brake hydraulic pressure. Flow to section 18FA of conduit 18F. When the pressure of the oil in the portion 18FB decreases due to the flow of the oil, 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 closes the port 80. Close again.

Thus, the control valve 22F has its solenoid 8
2 according to the applied voltage to the brake oil pressure control conduit 18
Since the pressure in the portion 18FB of F is controlled, the control valve 2 is controlled by controlling the driving voltage to the solenoid 82.
The pressure in the portion 18FB (referred to herein as the "upstream pressure") can be controlled to a desired pressure by the 2F.

In the illustrated embodiment, the check bypass conduit 24F shown in FIG. 1 is built in the control valve 22F, and has an internal passage 86 and a valve chamber 70 provided in the middle of the internal passage. The check valve 88 allows only the oil flow toward the portion 18FB.

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 front left wheel and the brake hydraulic control conduit 20FR for the front right wheel, respectively. In the middle of the brake hydraulic control conduit 20FL for the front left wheel and the brake hydraulic control conduit 20FR for the front right wheel, normally open solenoid valves 28FL and 28FR are provided, respectively. Solenoid on-off valve 28
Wheel cylinders 26FL and 26FR are provided on brake hydraulic control conduits 20FL and 20FR on both sides of FL and 28FR, respectively.
Non-return bypass conduits 30FL and 30FR, which allow only oil flow to the brake hydraulic control conduit 18F, are connected.

Electromagnetic valve 28FL and wheel cylinder 26
One end of an oil discharge conduit 32FL is connected to the brake hydraulic control conduit 20FL between the solenoid valve and the brake hydraulic control conduit 20FL between the solenoid on-off valve 28FR and the wheel cylinder 26FR.
One end of an oil discharge conduit 32FR is connected to FR.
In the middle of the oil discharge conduits 32FL and 32FR, normally closed solenoid on-off valves 34FL and 34FR are provided, respectively.
The other end of the oil discharge conduits 32FL and 32FR is connected to the connection conduit 36.
F connects to a buffer reservoir 38F for the front wheels.

As can be understood from the above description, the solenoid on-off valve 28
FL and 28FR are wheel cylinders 26FL and 2FL, respectively.
It is a pressure increasing valve for increasing or maintaining the pressure in 6FR,
The solenoid on-off valves 34FL and 34FR are pressure reducing valves for reducing the pressure in the wheel cylinders 26FL and 26FR, respectively. Accordingly, the solenoid on-off valves 28FL and 34FL cooperate with each other to increase or decrease the pressure in the left front wheel cylinder 26FL. A pressure increasing / decreasing valve for holding and holding is provided.
8FR and 34FR cooperate with each other to define a pressure increasing / decreasing valve for increasing / decreasing and holding the pressure in the wheel cylinder 26FR of the right front wheel.

The connecting conduit 36F is connected to the suction side of the pump 42F by the connecting conduit 40F.
Are provided two check valves 44F and 46F which allow only the flow of oil from the connecting conduit 36F to the pump 42F. The discharge side of the pump 42F is connected to the brake hydraulic pressure control conduit 18F by a connecting conduit 50F having a damper 48F on the way. Pump 42F and damper 4
A check valve 52F that allows only the flow of oil from the pump 42F to the damper 48F is provided in the connecting conduit 50F between the check valve 52F and the pump 8F.
Is provided.

One end of a connecting conduit 54F is connected to the connecting conduit 40F between the two check valves 44F and 46F, and the other end of the connecting conduit 54F is connected to the first master cylinder chamber 1.
Brake hydraulic control conduit 18 between 4A and control valve 22F
Connected to F. A normally closed solenoid on-off valve 60F is provided in the connection conduit 54F. The solenoid on-off valve 60F functions as a pump suction valve for controlling communication between the brake hydraulic control conduit 18F between the master cylinder 14 and the control valve 22F and the suction side of the pump 42F.

Thus, the control valve 22F is an electromagnetic on-off valve 60F
Indirectly in cooperation with the front left and right wheel cylinders 26
A first braking force control means common to the left and right front wheels for controlling the braking force of the left and right front wheels by increasing and decreasing the pressure in FL and 26FR constitutes a first braking force control means such as an electromagnetic on-off valve 28FL. The second braking force control means for the left front wheel and the right front wheel for individually controlling the braking force of the left and right front wheels by increasing and decreasing the pressure in the wheel cylinders 26FL, 26FR. The responsiveness of the braking pressure control by the control means is higher than the responsiveness of the braking pressure control by the first braking force control means.

Similarly, one end of a rear wheel brake oil pressure control conduit 18R is connected to the second master cylinder chamber 14B, and the other end of the brake oil pressure control conduit 18R is connected to the left rear wheel brake oil pressure control conduit 20RL. One end of a brake hydraulic control conduit 20RR for the right rear wheel is connected. A control valve 22R for a rear wheel, which is a normally-open electromagnetic on-off valve, is provided in the middle of the brake hydraulic pressure control conduit 18R.

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, and therefore, is controlled by controlling the drive voltage for a solenoid not shown in the figure. The pressure (upstream pressure) in the brake oil pressure control conduit 18R downstream of the valve 22R can be controlled to a desired pressure. Further, a check bypass pipe 24R that allows only oil flow from the second master cylinder chamber 14B to the brake hydraulic control pipe 20RL or the brake hydraulic control pipe 20RR is connected to the brake hydraulic control pipe 18R on both sides of the control valve 22R. I have.

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. The normally open solenoid valves 28RL and 28RR are provided in the middle of the left rear wheel brake hydraulic control conduit 20RL and the right rear wheel brake hydraulic control conduit 20RR, respectively. Solenoid on-off valve 28
The brake hydraulic control lines 20RL and 20RR on both sides of RL and 28RR have wheel cylinders 26RL and 26RR, respectively.
Non-return bypass conduits 30RL and 30RR that allow only oil flow toward the brake hydraulic control conduit 18R are connected.

The solenoid on-off valve 28RL and the wheel cylinder 26
One end of an oil discharge conduit 32RL is connected to a brake hydraulic control conduit 20RL between the brake hydraulic control conduit 20RL and the solenoid valve 28RR and the brake hydraulic control conduit 20RL between the wheel cylinder 26RR.
One end of an oil discharge conduit 32RR is connected to RR.
In the middle of the oil discharge conduits 32RL and 32RR, normally-closed solenoid on-off valves 34RL and 34RR are provided, respectively.
The other ends of the oil discharge conduits 32RL and 32RR are connected to a connection conduit 36.
R connects to the rear wheel buffer reservoir 38R.

As in the case of the front wheels, the solenoid on-off valves 28RL and 28RR are connected to the wheel cylinders 26RL and 26RR, respectively.
A pressure-intensifying valve for increasing or holding the internal pressure.
6RL and 26RR are pressure reducing valves for reducing the pressure in 26RR, and accordingly, the solenoid on-off valves 28RL and 34RL cooperate with each other to form a pressure increasing / reducing valve for increasing and decreasing the pressure in the wheel cylinder 26RL of the left rear wheel. The solenoid on-off valve 28
RR and 34RR cooperate with each other to define a pressure increasing / decreasing valve for increasing / decreasing and holding the pressure in the wheel cylinder 26RR of the right rear wheel.

The connecting conduit 36R is connected to the suction side of the pump 42R by the connecting conduit 40R.
Are provided two check valves 44R and 46R that allow only the oil flow from the connection conduit 36R to the pump 42R. The discharge side of the pump 42R is connected to the brake hydraulic pressure control pipe 18R by a connection pipe 50R having a damper 48R on the way. Pump 42R and damper 4
A check valve 52R that allows only the flow of oil from the pump 42R to the damper 48R is provided in the connecting conduit 50R between the check valve 52R and the pump 8R.
Is provided. The pumps 42F and 42R are driven by a common electric motor not shown in FIG.

One end of a connecting conduit 54R is connected to the connecting conduit 40R between the two check valves 44R and 46R, and the other end of the connecting conduit 54R is connected to the second master cylinder chamber 1.
Brake hydraulic control conduit 18 between 4B and control valve 22R
Connected to R. A normally closed solenoid on-off valve 60R is provided in the connection conduit 54R. The solenoid on-off valve 60R also functions as a pump suction valve for controlling communication between the brake hydraulic pressure control conduit 18R between the master cylinder 14 and the control valve 22R and the suction side of the pump 42R.

Thus, the control valve 22R is an electromagnetic on-off valve 60R
The wheel cylinders 26 of the left and right rear wheels indirectly in cooperation with
RL and 26RR constitute first common braking force control means for controlling the braking force of the left and right rear wheels by increasing and decreasing the pressure in the left and right rear wheels. The second braking force control means for the left rear wheel and the right rear wheel for individually controlling the braking force of the left and right rear wheels by increasing and decreasing the pressure in the wheel cylinders 26RL and 26RR of the left and right rear wheels. Thus, the responsiveness of the braking pressure control by the second braking force control means is higher than the responsiveness of the braking pressure control by the first braking force control means.

In the illustrated embodiment, each control valve and each on-off valve are set to the non-control position shown in FIG. 1 when the drive current is not supplied to the corresponding solenoid,
Thereby, the pressure in the first master cylinder chamber 14A is supplied to the wheel cylinders 26FL and 26FR, 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.

On the other hand, the control valves 22F and 22R are switched to the closed position, and the on-off valves 60F and 60R are opened.
When the pumps 42F and 42R are driven in a state where the on-off valves of the respective wheels are at the positions shown in FIG.
4 is pumped up by the pump, and the pressure pumped up by the pump 42F is supplied to the wheel cylinders 26FL and 26FR, and the wheel cylinder 26R
Since the pressure pumped up by the pump 42R is supplied to L and 26RR, the braking pressure of each wheel is controlled by the control valves 22F and 22R regardless of the depression force of the brake pedal 12.
It is increased or decreased by opening and closing the on-off valve (increase / decrease valve) of R and each wheel.

In this case, the pressure in the wheel cylinder is
On-off valves 28FL-28RR and on-off valves 34FL-34RR are shown in FIG.
When the pressure is increased (pressure increase mode) when in the non-control position shown in FIG. 1, the on-off valves 28FL-28RR are switched to the closed position and when the on-off valves 34FL-34RR are in the non-control position shown in FIG. Held (holding mode), the on-off valve 28
When the FL-28RR and the on-off valves 34FL-34RR are switched to the valve-open positions, the pressure is reduced (pressure reduction mode).

Control valves 22F and 22R, open / close valve 28FL
28RR, open / close valves 34FL-34RR, open / close valves 60F and 60
R is 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.

A signal indicating the master cylinder pressure Pm is sent from the pressure sensor 96 to the microcomputer 92, and the wheel speed Vwi of the left and right front wheels and the left and right rear wheels is sent from the wheel speed sensor 98i.
(I = fl, fr, rl, rr) are input from various sensors 100 such as a vehicle speed sensor. Further, the microcomputer 92 stores a braking control flow described later, and according to the braking control flow, the target braking pressure Pti and the target slip ratio SLti (i = fl, i) of the left and right front wheels and the left and right rear wheels.
fr, rl, rr) and the wheel speed Vwi of each wheel.
, The wheel acceleration Vwdi (i = fl, fr, rl, rr) is calculated.

Particularly in the illustrated embodiment, the control valve 22F is set so that the higher target braking pressure of the left and right front wheels is set to the target upstream pressure Ptf of the front wheels, and the upstream pressure of the front wheels becomes the target upstream pressure Ptf. Controlled. Similarly, the higher target braking pressure of the left and right rear wheels is set to the target upstream pressure Ptr of the rear wheels, and the control valve 22R is controlled such that the rear wheel-side upstream pressure becomes the target upstream pressure Ptr.

Then, it is determined whether or not the wheel acceleration Vwdi is smaller than the reference value Vwdo (negative constant) for the wheel having the higher target braking pressure among the left and right front wheels, and the wheel acceleration Vwd is determined.
When i is less than the reference value Vwdo, it is determined that the braking force generation region of the wheel is in the linear region, and the braking pressure of the wheel is controlled to the corresponding target braking pressure Pti by the control valve 22F. The braking pressure of the front wheels on the right and left opposite sides is controlled to a corresponding target braking pressure Pti by a pressure increasing / decreasing control valve.

On the other hand, when the wheel acceleration Vwdi of the left or right front wheel having the higher target braking pressure is equal to or greater than the reference value Vwdo, it is determined that the braking force generation region of the wheel is in the non-linear region, and The braking pressures of the front wheels on the left and right sides are controlled to the corresponding target braking pressures Pti by the pressure increasing / decreasing control valves.

Similarly, a determination is made as to whether the wheel acceleration Vwdi is smaller than a reference value Vwdo (negative constant) for the one of the left and right rear wheels having a higher target braking pressure, and the wheel acceleration Vwdi is determined.
When wdi is less than the reference value Vwdo, it is determined that the braking force generation region of the wheel is in the linear region, and the braking pressure of the wheel is controlled to the corresponding target braking pressure Pti by the control valve 22R. The braking pressure of the rear wheels on the right and left sides is controlled to a corresponding target braking pressure Pti by a pressure increasing / decreasing control valve.

On the other hand, when the wheel acceleration Vwdi of one of the left and right rear wheels having the higher target braking pressure is equal to or greater than the reference value Vwdo, it is determined that the braking force generation region of the wheel is in the non-linear region. The braking pressure of each of the wheels and the rear wheels on the left and right sides is controlled to the corresponding target braking pressure Pti by the pressure increasing / decreasing control valve.

In the illustrated embodiment, if the brake pressure of the wheel having the higher target brake pressure is to be reduced, the master cylinder pressure Pm must be equal to or higher than the target brake pressure of the wheel. If 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 brake hydraulic control conduits 18F, 18R between the control valve and the pump.
The upstream pressure and the pressure in the wheel cylinders are controlled to the target braking pressure by discharging the oil in the inside through the control valves to the connection conduits 54F and 54R.

On the other hand, when the master cylinder pressure Pm is equal to or higher than the target braking pressure of the wheel, the pressure-reducing valve is controlled to open and close while the pressure-increasing valve is open, so that the pressure in the wheel cylinder to be reduced is reduced. The oil is discharged to the buffer reservoirs 38F and 38R via the brake hydraulic pressure control conduit FL and the like and the connection conduits 36F and 36R, whereby the pressure in the wheel cylinder is reduced to the target braking pressure.

Next, a braking control routine in the illustrated embodiment will be described with reference to flowcharts shown in FIGS. The control according to the flowcharts shown in FIGS. 3 to 5 is started by closing an ignition switch (not shown) and is repeatedly executed at predetermined time intervals.

First, in step 10, the pressure sensor 9
A signal indicating the master cylinder pressure Pm detected by the controller 6 is read, and in step 20, the behavior of the vehicle is estimated based on vehicle running parameters such as the vehicle speed detected by various sensors 98. For example, when in the spin state or the drift-out state, the target braking pressure Pti and the target slip ratio SLti of each wheel for suppressing the spin state or the drift-out state are calculated in a manner known in the art.

In step 30, it is determined whether or not the braking pressure needs to be controlled by determining whether or not the target braking pressure Pti of any one of the wheels is higher than the pressure at the time of non-control. When a negative determination is made, that is, when it is determined that the control of the braking pressure is not necessary, each valve is set to the non-control position shown in FIG.
Returning to step 50, when the affirmative determination, that is, the determination that the control of the braking pressure is necessary is performed, the process proceeds to step 50.

In step 50, the front-wheel-side target upstream pressure Ptf is set to the larger value of the left front wheel target braking pressure Ptfl and the right front wheel target braking pressure Ptfr. Is set to fl indicating the left front wheel, and k is set to rl indicating the right front wheel.

In step 70, it is determined whether or not the target braking pressure Ptj of the relevant wheel (in this case, the front left wheel) is equal to or higher than the target braking pressure Ptk of the right and left opposite wheels (in this case, the front right wheel). It is determined whether or not the valve 22F should be controlled based on the target braking pressure of the wheel. If the determination is affirmative, the process proceeds to step 100, and if the determination is negative, the process proceeds to step 80. Normal control for increasing / decreasing the wheel cylinder pressure is performed according to the routine shown in FIG.

In step 100, the target drive voltage for the solenoid of the control valve 22F is calculated based on the target upstream pressure Ptf on the front wheel side, and the on-off valves 28FL to 28RR are calculated.
Are opened and the on-off valves 34FL to 34RR are closed, the pumps 42F and 42R are driven, and the on-off valves 60F and 6R are opened.
0R is opened, and the control valve 22F is controlled at the target drive voltage, whereby the upstream pressure on the front wheel side is reduced to the target upstream pressure Ptf.
Is controlled.

In step 105, the wheel acceleration Vwdj is calculated as the time differential value of the wheel speed Vwj of the left and right front wheels having the higher target braking pressure Pti, and whether the wheel acceleration Vwdj is smaller than the reference value Vwdo. Is determined,
When the determination is affirmative, the routine proceeds to step 80, and when the determination is negative, the routine proceeds to step 110.

In step 110, the wheel cylinder pressure Pj of the wheel is calculated by estimation based on the supply and discharge of oil to and from the wheel cylinder in a manner known in the art, and the target braking pressure of the wheel is calculated. It is determined whether or not Ptj is less than the wheel cylinder pressure Pj of the wheel, that is, whether or not the braking pressure of the wheel is to be reduced. If a negative determination is made, step 140 is performed. The process proceeds to step 120 when the affirmative determination is made.

In step 120, it is determined whether or not the master cylinder pressure Pm is equal to or higher than the target brake pressure Ptj of the wheel, that is, the brake pressure cannot be reduced to the target brake pressure by controlling the control valve 22F. It is determined whether or not the situation is satisfied. If a negative determination is made, step 16 is executed.
0, and when a positive determination is made,
At 0, the front-wheel-side intake valve 60F is closed, the pressure-intensifying valve 28FR or 28FR of the wheel is opened, and the pressure-reducing valve 34FL or 34FR of the wheel is moved to the deviation between the target braking pressure Ptj and the wheel cylinder pressure Pj. Open / close control is performed at a duty ratio based on the duty ratio.

In step 140, it is determined whether or not the target braking pressure Ptj of the wheel is the same as the wheel cylinder pressure Pj, that is, whether or not it is not necessary to increase or decrease the braking pressure. When the determination is made, step 150
When the pressure-intensifying valve 28FL or 28FR of the wheel is closed and the pressure-reducing valve 34FL or 34FR of the wheel is closed and a negative determination is made in step 160, the pressure increasing valve 28FL or 28FR of the wheel is determined in step 160. Is opened, and the pressure reducing valve 34FL or 34FR of the wheel is closed.

In step 200, after j is set to fr indicating the right front wheel and k is set to fl indicating the left front wheel, the same processing as in steps 70 to 160 described above is performed. The braking force of the right front wheel is controlled.

In step 300, the target upstream pressure Ptr on the rear wheel side is set to the larger of the target braking pressure Ptrl of the left rear wheel and the target braking pressure Ptrr of the right rear wheel.
At 0, j is set to rl indicating the left rear wheel and k is set.
Is set to rr indicating the right rear wheel.
The same processing as 160 is performed, whereby the braking force of the left rear wheel is controlled. In step 500, j is set to rr indicating the right rear wheel and k is set to rl indicating the left rear wheel. After that, the same processing as in the above steps 70 to 160 is performed, whereby the braking force of the right rear wheel is controlled.

In step 82 of the normal pressure increase / decrease control routine shown in FIG. 5, the actual slip ratio S
Lj is calculated, and it is determined whether or not the actual slip ratio SLj exceeds the target slip ratio SLtj of the wheel, that is, whether or not the braking pressure is to be reduced is determined. When the affirmative determination is made, the process proceeds to step 86, and in step 84, the pressure reducing valve of the wheel is set to the actual slip rate SLj and the target slip rate in a state where the pressure increasing valve of the wheel is closed in step 84. Opening / closing control is performed at a duty ratio based on a deviation from SLtj, whereby pressure reduction control is performed so that the actual slip ratio of the wheel becomes the target slip ratio.

In step 86, it is determined whether or not the actual slip ratio SLj of the wheel is less than the target slip ratio SLtj, that is, whether or not the braking pressure of the wheel is to be increased. When a negative determination is made, the braking pressure is maintained by closing the pressure increasing valve and the pressure reducing valve of the wheel in step 88, and when an affirmative determination is made, the process proceeds to step 90. The pressure increasing valve of the wheel is opened and closed at a duty ratio based on the difference between the actual slip rate SLj and the target slip rate SLtj, and the pressure reducing valve of the wheel is closed, thereby reducing the actual slip rate of the wheel to the target slip rate. The pressure increase control is performed so as to obtain the ratio.

Thus, according to the illustrated embodiment, a negative determination is made in step 70 for the one of the left and right wheels having the lower target braking pressure, and in step 80, the increase / decrease by the normal pressure increasing / decreasing valve is performed. Pressure control is performed, whereby the braking force is controlled such that the actual slip ratio of the wheel becomes the target slip ratio.

For the wheel having the higher target braking pressure among the left and right wheels, an affirmative determination is made in step 70, and in step 100, the upstream pressure is set to the higher value of the target braking pressure for the left and right wheels. If the control valve is controlled so that the target upstream pressure becomes equal to and the wheel acceleration Vwdj is less than the reference value Vwdo, and the braking force generation region of the wheel having the higher target braking pressure is a linear region, a negative determination is made in step 105. A determination is made and steps 100 to 160 are executed to control the braking force so that the braking pressure Pj of the wheel becomes the target braking pressure Pti.

On the other hand, when the wheel acceleration Vwdj is equal to the reference value Vw
When the braking force generation region of the wheel having the target braking pressure higher than "do" is a non-linear region, an affirmative determination is made in step 105, and in step 80, pressure increasing / decreasing control by the pressure increasing / decreasing valve is performed. Thereby, the braking force is controlled such that the actual slip ratio of the wheel becomes the target slip ratio.

Therefore, according to the illustrated embodiment, for both the front wheel side and the rear wheel side, the braking force generation region of the left or right wheel having the higher target braking pressure is a linear region. Sometimes, the control valve 22F having low response,
By controlling the 22R, the braking force is controlled so that the braking pressure Pj of the corresponding wheel becomes the target braking pressure Pti. The braking force is controlled so that the actual slip ratio of the wheel becomes the target slip ratio, so that the braking force generation region of the left or right wheel having the higher target braking pressure is a linear region or a non-linear region. Regardless, the braking force of the wheel can be controlled with higher responsiveness as compared with the case where the braking force of the wheel is controlled by the control valves 22F and 22R, and the braking force of the wheel is controlled by the pressure increasing / decreasing valve. As compared with the case, the energy consumed by the control of the valve can be reduced, and the decrease in the durability of the pressure reducing valve due to the repeated opening and closing can be reduced.

In general, there is a relationship shown in FIG. 6 between the slip ratio SL of the wheel and the braking force Fb of the wheel. When the braking force generation region of the wheel is in the linear region, the slip with respect to the braking force Fb is determined. Although the ratio of the rate SL is substantially constant, when the braking force is increased and the braking force generation region of the wheel becomes a non-linear region, the ratio of the slip ratio SL to the braking force Fb decreases.

Therefore, for example, as shown in FIG. 7, when the braking force of the wheel is increased to a value larger than 0, the wheel acceleration Vwdi gradually decreases to a negative value from 0, and the braking force of the wheel is generated. When the area becomes more than the time point t1 at which the area becomes a non-linear area from a linear area, the area rapidly decreases. Therefore, if the wheel acceleration Vwdi at the time point t1 is set as the reference value Vwdo, it can be determined whether the wheel acceleration Vwdi is less than the reference value Vwdo.

According to the illustrated embodiment, step 105
, The wheel acceleration Vwdi is calculated based on the wheel speed Vwi, and it is determined whether or not the braking force generation region is a non-linear region by determining whether or not the wheel acceleration Vwdi is smaller than the reference value Vwdo. Therefore, it is possible to determine whether or not the braking force generation region is a non-linear region by a simple and simple calculation as compared with the case of the braking control device according to the above-mentioned proposal.

In particular, according to the illustrated embodiment, when the braking force generation region of the wheel having the higher target braking pressure is in the linear region, and the negative determination is made in step 105, the target braking pressure Even when Ptj is lower than the wheel cylinder pressure Pj and the braking pressure of the wheel should be reduced, the master cylinder pressure Pm is still lower than the target braking pressure Ptj of the wheel.
If not, a negative determination is made in step 120, and in step 160 the booster / reducer valve is set to the uncontrolled position, thereby causing the brake hydraulic control conduit 18F or 18R between the control valve and the pump to Oil flows through control valve 22F or 22R to connect conduit 54F or 54R.
The upstream pressure is controlled to the target upstream pressure by being discharged to the outlet.

On the other hand, when the braking pressure is to be reduced, the master cylinder Pm sets the target braking pressure Ptj of the corresponding wheel.
If so, a positive determination is made in steps 110 and 120, respectively, and in step 130, the suction valve 60F or 60R is closed, the pressure increasing valve is opened, and the pressure reducing valve is set at a predetermined duty ratio. It is opened and closed, whereby the oil in the wheel cylinder of the wheel is discharged to the buffer reservoir 38F or 38R via the brake hydraulic control conduit 20FL or the like and the connecting conduit 36F or 36R, whereby the wheel cylinder pressure is controlled to the target upstream pressure. .

Therefore, according to the illustrated embodiment, even when the target brake pressure of the wheel to be controlled by the upstream pressure is lower than the wheel cylinder pressure and the master cylinder pressure is equal to or higher than the target brake pressure of the wheel. Thus, the wheel cylinder pressure can be reliably reduced to the target upstream pressure, whereby the braking pressure of the wheel with the higher target braking pressure among the left and right wheels can be reliably reduced to the target braking pressure.

According to the illustrated embodiment, the target braking pressure Ptj of the wheel whose braking pressure is controlled by the upstream pressure is lower than the wheel cylinder pressure Pj and the master cylinder pressure Pm is equal to or higher than the target braking pressure Ptj of the wheel. In some cases, in step 130, the pressure increasing valve is opened and the pressure reducing valve is opened / closed at a predetermined duty ratio, and the suction valve 60F or 6
Since 0R is closed, it is ensured that the depression stroke of the brake pedal 12 unnaturally increases due to the oil in the master cylinder 14 flowing to the pump suction side via the pump suction valve 60F or 60R. Can be prevented.

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

For example, in the illustrated embodiment, when an affirmative determination is made in step 105, the braking force is set to the target slip in step 80, as in the case of the wheel having the lower target braking pressure Ptj. The control is performed by the pressure increasing / decreasing valve based on the rate SLti.
When the affirmative determination is made in the above, the braking force may be modified so as to be controlled by the pressure increasing / decreasing valve based on the target braking pressure Ptj so that the braking pressure Pj becomes the target braking pressure Ptj.

In the illustrated embodiment, on-off valves 28FL-28RR as pressure-increasing valves and on-off valves 34FL-34RR as pressure-reducing valves cooperate with each other to increase and maintain the pressure in the corresponding wheel cylinder. The pressure increasing and reducing valves are configured to increase and decrease the pressure.
The switching position may be replaced with a single switching valve having a holding position and a depressurizing position. In this case, in a situation where the master cylinder pressure Pm is equal to or higher than the target braking pressure to be controlled by the control valve, the braking pressure of the relevant wheel is increased. When the pressure is to be reduced, the switching pressure is set to the pressure reducing position, so that the braking pressure of the wheel is reduced to the target braking pressure.

In the illustrated embodiment, the braking device 10 includes a brake hydraulic system for the left front wheel and the right front wheel and a brake hydraulic system for the left rear wheel and the right rear wheel. May include a brake hydraulic system for the left front wheel and the right rear wheel and a brake hydraulic system for the right front wheel and the left rear wheel.

In the illustrated embodiment, the target braking pressure Pti and the target slip ratio SLti of each wheel are calculated for the purpose of controlling the behavior of the vehicle. The rate SLti may be calculated for any vehicle control purpose known in the art.

In the illustrated embodiment, when it is not necessary to control the wheel braking pressure for the purpose of vehicle control such as behavior control, each valve is set to the non-control position shown in FIG. The control valve and the pump suction valve are also controlled when the driver performs a braking operation,
Thus, the braking pressure of each wheel may be controlled in a brake-by-wire manner according to the master cylinder pressure Pm.

Further, in the illustrated embodiment, the wheel cylinder pressure Pi of each wheel is estimated based on the supply and discharge of oil to and from the wheel cylinder, but the wheel cylinder pressure Pi is detected by a pressure sensor. You may.

[0096]

As is apparent from the above description, according to the first aspect of the present invention, the optimum braking force control means according to the result of determination as to whether the braking force generation region of the wheel is a non-linear region or not. According to the configuration of claim 2, it is possible to determine whether or not the braking force generation region of the wheel is a non-linear region without requiring a complicated calculation or an expensive control device. can do.

According to the third aspect of the present invention, when the braking force generation region of the wheel is a linear region and high response is not required, the braking pressure is controlled by the control valve, and the braking force generation region of the wheel is non-linear. Since the braking pressure is controlled by the pressure increasing / decreasing valve when high response is required in the range, the pressure increasing / decreasing valve is prevented from being repeatedly opened / closed in a situation where high response is not required, thereby preventing a decrease in durability. The braking force can be controlled with good responsiveness in a situation where a high response is required.

According to the fourth aspect of the present invention, the optimum braking force control means can be used in both cases where the braking force generation region is in the linear region and where the braking force generation region is in the non-linear region. Can be selected, and the selected braking force control means can be optimally controlled.

[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 control valve for a front wheel shown in FIG. 1;

FIG. 3 is a flowchart illustrating a main part of a braking control routine according to the embodiment.

FIG. 4 is a flowchart showing the remaining part of the braking control routine of the embodiment.

FIG. 5 is a flowchart showing a normal pressure increase / decrease control routine executed in step 80 of FIG. 3;

FIG. 6 is a graph showing a relationship between a wheel slip ratio SL and a wheel braking force Fb.

FIG. 7 is a graph showing an example of a change in wheel acceleration Vwdi when the braking force of the wheel is increased to a value greater than 0.

[Explanation of symbols]

 10: Braking device 14: Master cylinder 22F, 22R: Control valve 26FL, 26FR, 26RL, 26RR: Wheel cylinder 42F, 42R: Oil pump 28FL-28RR, 34FL-34RR: On-off valve 42F, 42R: Pump 48F, 48R: Damper 48 accumulator 70 valve chamber 74 valve element 84 compression coil spring 88 check valve 90 electronic control unit 96 pressure sensor 98i wheel speed sensor 100 various force sensors

Claims (4)

[Claims] A plurality of braking force control units having different responsiveness for controlling a braking force of a wheel; a braking force generation region determining unit for determining whether a braking force generation region of the wheel is a non-linear region; The braking force control means used for controlling the braking force is selected from the plurality of braking force control means in accordance with the determination result of the braking force generation area determination means, and the braking control of the wheel is performed using the selected braking force control means. And a selection control means for controlling power. 2. The braking force generation area determining means includes means for detecting a wheel speed and means for calculating a wheel acceleration based on the detected wheel speed, and controls when the wheel acceleration is less than a reference value. The vehicle braking control device according to claim 1, wherein the power generation region is determined to be a non-linear region. 3. A vehicle, comprising: a hydraulic fluid supply passage for supplying hydraulic fluid pressure of a master cylinder to a wheel cylinder provided corresponding to a wheel; and first braking force control means provided in the hydraulic fluid pressure supply passage. A control valve, a pressure increasing / decreasing valve provided in the working fluid pressure supply passage between the control valve and the wheel cylinder, and constituting a second braking force control unit; and the control valve and the pressure increasing / decreasing valve. A high-pressure liquid supply source for supplying a high-pressure working liquid to the working fluid pressure supply passage between
When the braking force generation area is determined to be a linear area by the braking force generation area determination means, the selection control means controls the control valve to control the hydraulic fluid between the control valve and the wheel cylinder. By controlling the pressure in the pressure supply passage, the braking force of the wheels is controlled, and when the braking force generation region is determined by the braking force generation region determining means to be a non-linear region, the pressure increasing / decreasing valve is controlled. The vehicle braking control device according to claim 1 or 2, wherein the braking force of the wheel is controlled. 4. The apparatus according to claim 1, wherein said selection control means has means for calculating a target braking pressure and a target slip ratio. When the braking force generation area is determined to be a linear area by said braking force generation area determination means, said operation is performed. The control valve is controlled so that the pressure in the hydraulic pressure supply passage becomes the target braking pressure, and when the braking force generation region is determined to be a non-linear region by the braking force generation region determination means, the slip ratio of the wheel is reduced. 4. The braking control device for a vehicle according to claim 3, wherein the pressure increasing / decreasing valve is controlled so as to achieve the target slip ratio.