WO2016039196A1

WO2016039196A1 - Brake control device

Info

Publication number: WO2016039196A1
Application number: PCT/JP2015/074629
Authority: WO
Inventors: 淳松岡
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2014-09-09
Filing date: 2015-08-31
Publication date: 2016-03-17
Also published as: JP2016055739A

Abstract

A brake control device calculates a target wheel cylinder fluid pressure on the basis of a stroke-corresponding target wheel cylinder fluid pressure that is set in correspondence to the operation stroke of the brake pedal by the driver, and a master cylinder fluid pressure-corresponding target wheel cylinder fluid pressure that is set in correspondence to a master cylinder fluid pressure, suctions brake fluid from a master cylinder using a pump, and increases the wheel cylinder fluid pressure so as to achieve the target wheel cylinder fluid pressure.

Description

Brake control device

The present invention relates to a brake control device.

Patent Document 1 discloses a brake control device that uses a hydraulic pressure source to suck in brake fluid in a master cylinder or a reservoir and discharges it to the wheel cylinder to increase the wheel cylinder hydraulic pressure.

Japanese Patent Application Laid-Open No. 10-329678

However, if the degree of increase in the wheel cylinder hydraulic pressure (hereinafter referred to as the brake stiffness) with respect to the amount of brake fluid supplied to the wheel cylinder side is high, the amount of brake fluid pumped out from the master cylinder side decreases and the stroke of the brake pedal There is a possibility that the board stepping phenomenon in which the

An object of the present invention is to avoid a plate stepping phenomenon in a brake control device and to achieve a good pedal feeling.
An object of the present invention is to provide a brake control device capable of avoiding a plate stepping phenomenon and achieving good pedal feeling.

In the present invention, the target wheel cylinder hydraulic pressure corresponding to the stroke set according to the operation stroke of the driver's brake pedal and the target wheel cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure set according to the master cylinder hydraulic pressure The target wheel cylinder hydraulic pressure is calculated, the brake fluid is sucked from the master cylinder by the pump, and the wheel cylinder hydraulic pressure is increased to achieve the target wheel cylinder hydraulic pressure.

FIG. 1 is a block diagram of a brake control device according to a first embodiment. It is a control block diagram showing the concept of target foil cylinder liquid pressure setting of the present invention. FIG. 2 is a control block diagram showing a control configuration of brake assist control according to the first embodiment. FIG. 7 is a block diagram of a brake control device according to a second embodiment. FIG. 7 is a block diagram of a brake control device according to a third embodiment. FIG. 16 is a control block diagram illustrating a control configuration of brake assist control according to a fourth embodiment.

Example 1
FIG. 1 is a block diagram of a brake control device according to a first embodiment. The fluid pressure control unit HU adjusts the braking force applied to each wheel of the vehicle, and based on the command from the brake control unit BCU, the wheel cylinder W / C (RL) of the left rear wheel and the wheel cylinder of the right front wheel The fluid pressures of W / C (FR), wheel cylinder W / C (FL) of the left front wheel, and wheel cylinder W / C (RR) of the right rear wheel are increased or decreased or held.
The fluid pressure control unit HU has a piping structure called X piping, which is composed of two systems of a P system and an S system. By adopting the X piping, even if one of the piping systems fails, the other piping system can be used to generate half the braking force in the normal state. In addition, P attached to the end of the code of each part indicated in FIG. 1 shows P system, S shows S system, RL, FR, FL, RR show left rear wheel, right front wheel, left front wheel, right rear Indicates that it corresponds to the circle. In the following description, when the P, S systems or the respective wheels are not distinguished, the description of P, S or RL, FR, FL, RR is omitted.

The hydraulic control unit HU of the first embodiment uses a closed hydraulic circuit. Here, the “closed hydraulic circuit” refers to a hydraulic circuit that returns the brake fluid supplied to the wheel cylinder W / C to the reservoir tank RSV via the master cylinder M / C. Incidentally, for the closed hydraulic circuit, the "open hydraulic circuit" is a hydraulic circuit capable of returning the brake fluid supplied to the wheel cylinder W / C directly to the reservoir tank RSV without via the master cylinder M / C. It is said.
The brake pedal BP is connected to the master cylinder M / C via an input rod IR. The pedal effort input to the brake pedal BP is boosted by the brake booster BB. The brake booster BB has a negative pressure sensor 18 that detects a booster negative pressure. Master cylinder M / C generates a brake fluid pressure boosted by brake booster BB. The input rod IR has a stroke sensor 17 that detects the stroke amount of the brake pedal BP.
The wheel cylinder W / C (RL) of the left rear wheel RL and the wheel cylinder W / C (FR) of the right front wheel FR are connected to the S system, and the wheel cylinder W / C (left) of the left front wheel FL is connected to the P system. FL) The wheel cylinder W / C (RR) of the right rear wheel RR is connected. Further, in the P system and the S system, pumps PP and PS (hereinafter, sometimes collectively referred to as pump P) are provided. The pumps PP and PS are driven by one motor M. The motor M controls the motor rotational speed according to a desired drive amount. The pumps PP and PS are plunger pumps. In addition, it may replace with a plunger pump and may employ | adopt a gear pump, and it does not specifically limit.

Master cylinder M / C and wheel cylinder W / C are connected by pipe line 1 and pipe line 2. The conduit 2S branches into the conduits 2RL and 2FR, the conduit 2RL is connected to the wheel cylinder W / C (RL), and the conduit 2FR is connected to the wheel cylinder W / C (FR). The conduit 2P branches into the conduits 2FL and 2RR, the conduit 2FL is connected to the wheel cylinder W / C (FL), and the conduit 2RR is connected to the wheel cylinder W / C (RR).
On the conduit 1 is provided a gate-out valve 3 which is a normally open proportional control valve. A master cylinder hydraulic pressure sensor 40 for detecting a master cylinder hydraulic pressure is provided at a position closer to the master cylinder than the gate out valve 3P of the pipeline 1P of the P system. A pipe 4 is provided on the pipe 1 in parallel with the gate out valve 3. A check valve 5 is provided on the conduit 4. The check valve 5 allows the flow of the brake fluid from the master cylinder M / C to the wheel cylinder W / C and prohibits the flow in the opposite direction.
A solenoid-in valve 6, which is a normally open proportional control valve corresponding to each wheel cylinder W / C, is provided on the conduit 2. A pipeline 7 is provided on the pipeline 2 in parallel with the solenoid-in valve 6. A check valve 8 is provided on the conduit 7. The check valve 8 permits the flow of brake fluid in the direction from the wheel cylinder W / C to the master cylinder M / C, and prohibits the flow in the opposite direction.

The discharge side of the pump P and the pipe 2 are connected by a pipe 9. A discharge valve 10 is provided on the conduit 9. The discharge valve 10 allows the flow of the brake fluid in the direction from the pump P toward the conduit 2 and prohibits the flow in the opposite direction.
The position on the master cylinder side of the gate-out valve 3 of the conduit 1 and the suction side of the pump P are connected by the conduit 11 and the conduit 12. A pressure control reservoir 13 is provided between the conduit 11 and the conduit 12.
A position closer to the wheel cylinder than the solenoid in valve 6 of the pipe line 2 and the pressure control reservoir 13 are connected by a pipe line 14. The conduit 14S branches into the conduits 14RL and 14FR, and the conduit 14P branches into the conduits 14FL and 14RR and is connected to the corresponding wheel cylinder W / C.
A solenoid-out valve 15, which is a normally closed solenoid valve, is provided on the conduit.
The pressure control reservoir 13 is provided with a pressure sensitive check valve 16. The check valve 16 prohibits the brake fluid from flowing into the pressure control reservoir 13 when the pressure in the conduit 11 becomes a high pressure exceeding a predetermined pressure, whereby a high pressure is applied to the suction side of the pump P To prevent The check valve 16 is opened regardless of the pressure in the pipe line 11 when the pump P operates and the pressure in the pipe line 12 is lowered, and the pressure of the brake fluid in the pressure control reservoir 13 is reduced. Allow inflow.

[Brake control]
The brake control unit BCU performs antilock brake (ABS) control as brake control. When ABS control detects that the wheel has a tendency to lock during the driver's brake operation, the wheel cylinder hydraulic pressure is reduced, maintained, increased to prevent maximum lock while preventing lock of the wheel. It is control which repeats pressure. At the time of ABS pressure reduction control, the solenoid in valve 6 is closed and the solenoid out valve 15 is opened from the state of FIG. 1 to release the brake fluid of the wheel cylinder W / C to the pressure control reservoir 13 to reduce the wheel cylinder hydraulic pressure. In the ABS holding control, the wheel cylinder hydraulic pressure is held by closing the solenoid in valve 6 and the solenoid out valve 15 together. In the ABS pressure increase control, the solenoid in valve 6 is controlled in the opening direction and the solenoid out valve 15 is closed, and the wheel cylinder hydraulic pressure is increased by supplying the brake fluid from the master cylinder M / C to the wheel cylinder W / C. .
Further, the hydraulic control unit HU of the first embodiment operates the respective valves and the pump P as brake control to detect that the oversteer tendency or the understeer tendency has become stronger at the time of turning of the vehicle. Vehicle behavior stabilization control to control the wheel cylinder fluid pressure of the wheel to stabilize the vehicle behavior, the wheel cylinder W / C generates a pressure higher than the pressure actually generated by the master cylinder M / C when the driver operates the brake It is possible to implement automatic brake control such as control for automatically generating a braking force according to the relative relationship with the preceding vehicle by brake assist control and auto cruise control.

In each brake control, the brake control unit BCU uses signals from other vehicle sensors (wheel speed sensor, steering angle sensor, yaw rate sensor, lateral acceleration sensor, etc.) in addition to the master cylinder hydraulic pressure sensor 40 and the stroke sensor 17. A target fluid pressure of the wheel cylinder W / C is generated on the basis of this. Then, the respective valves of the hydraulic control unit HU and the motor M are driven such that the wheel cylinder hydraulic pressure matches the target hydraulic pressure. The motor M, the gate out valve 3 and the solenoid in valve 6 perform PWM control at a fixed control cycle. The solenoid out valve 15 is on / off controlled. The brake control unit BCU has a motor drive unit 20 that drives the motor M.

(Regarding Brake Assist Control) Next, the brake assist control of the first embodiment will be described. In recent years, the negative pressure of the engine has tended to decrease from the viewpoint of improving fuel consumption. Therefore, a scene where the boosting function by the brake booster BB can not be sufficiently secured is assumed. Therefore, there is expected a brake assist control that drives the pump P in accordance with the driver's brake pedal operation state and compensates for the decrease in the boosting function by the brake booster BB. In the brake assist control, the gate out valve 3 is closed (or closed with an electromagnetic force that generates a necessary differential pressure by balance control), and controlled so as to overcome the electromagnetic force and open when the required differential pressure is exceeded. And the brake fluid in the master cylinder M / C is pumped up by the pump P and supplied to the wheel cylinder W / C. This secures the stroke when the driver depresses the brake pedal and assists the brake pedal operating force. When the pump P is operated, the pressure in the conduit 12 is lowered and the check valve 16 is automatically opened regardless of the pressure in the conduit 11 and the master cylinder M is opened via the pressure control reservoir 13. The brake fluid flows into the suction side of the pump P from C / C. Thus, during the brake assist control, movement of the brake fluid occurs from the master cylinder M / C side to the wheel cylinder W / C side.

Here, it is assumed that the target wheel cylinder hydraulic pressure is calculated according to the stroke amount of the brake pedal and the pump P is operated. When a target wheel cylinder is set according to a certain stroke amount and the pump P is driven, it is possible to generate a wheel cylinder pressure according to the stroke amount. However, the brake stiffness between the fluid pressure control unit HU and the wheel cylinder W / C can not be said to be constant due to manufacturing variations or aging. For example, when the brake stiffness is low, it is necessary to pump a large amount of brake fluid from the master cylinder M / C in order to achieve the target wheel cylinder hydraulic pressure. In this case, the brake pedal BP may be inhaled and an excessive stroke may occur, so that the driver's braking intention can not be accurately reflected, and the pedal feeling may be deteriorated. On the other hand, when the brake stiffness is high, the amount of brake fluid pumped up from the master cylinder M / C to achieve the target wheel cylinder hydraulic pressure is small. In this case, the brake fluid in the master cylinder M / C does not decrease, and there is a possibility that a plate depression phenomenon that the stroke of the brake pedal BP can not be secured may occur, and the driver's braking intention can not be accurately reflected. Deterioration is a concern.

Therefore, in the first embodiment, in setting the target wheel cylinder hydraulic pressure, in addition to the stroke corresponding target wheel cylinder hydraulic pressure P1 * based on the stroke amount STR of the brake pedal, the master cylinder hydraulic pressure correspondence based on the master cylinder hydraulic pressure Pmc. Calculating a final target wheel cylinder hydraulic pressure P * based on the target wheel cylinder hydraulic pressure P2 * corresponding to the stroke and the target wheel cylinder hydraulic pressure P2 * corresponding to the master cylinder; did.

FIG. 2 is a control block diagram showing the concept of target wheel cylinder hydraulic pressure setting according to the present invention. The stroke-corresponding target wheel cylinder hydraulic pressure calculation unit 101 calculates a stroke-corresponding target wheel cylinder hydraulic pressure P1 * corresponding to the stroke amount STR detected by the stroke sensor 17. Master cylinder hydraulic pressure corresponding target wheel cylinder hydraulic pressure calculation unit 102 multiplies master cylinder hydraulic pressure Pmc detected by master cylinder hydraulic pressure sensor 40 by a conversion coefficient K to obtain master cylinder hydraulic pressure corresponding target wheel cylinder hydraulic pressure P2 * Calculate The target wheel cylinder hydraulic pressure calculation unit 103 calculates the final target wheel cylinder hydraulic pressure P * by adding the target wheel cylinder hydraulic pressure P1 * for the stroke and the target wheel cylinder P2 * for the master cylinder hydraulic pressure. When the target wheel cylinder hydraulic pressure P * is output to the motor control unit (motor drive unit) 20 in the brake control unit BCU, the pump P is driven by the motor M. The motor control is not particularly limited as long as the existing motor control logic is used appropriately.

Here, the operation obtained by the above configuration will be described. When the brake stiffness is low, the stroke amount target stroke increases, so the stroke-corresponding target wheel cylinder hydraulic pressure P1 * increases. At this time, since the master cylinder hydraulic pressure Pmc is hard to rise, the target wheel cylinder P2 * corresponding to the master cylinder hydraulic pressure becomes smaller. As a result, when the stroke amount STR is excessive, since the master cylinder M / C does not rise, the brake fluid is not excessively pumped up, and the excessive stroke can be avoided. On the other hand, when the brake stiffness is high, the stroke amount STR does not easily increase, and the stroke corresponding target wheel cylinder hydraulic pressure P1 * does not increase so much. At this time, since the master cylinder hydraulic pressure Pmc is apt to rise, the target wheel cylinder P2 * corresponding to the master cylinder hydraulic pressure becomes large. As a result, when the stroke amount STR is insufficient, the brake fluid is pumped up in response to the increase of the master cylinder fluid pressure, so that the plate depressing phenomenon can be avoided and an appropriate stroke amount STR can be secured. As described above, by using the master cylinder fluid pressure to eliminate the excessive stroke and the plate stepping phenomenon that occur when control is performed using only the stroke amount, the driver's braking intention is accurately reflected regardless of the brake rigidity. While, it is possible to provide a brake control device having a good pedal feeling.

FIG. 3 is a control block diagram showing a control configuration of brake assist control according to the first embodiment. The configuration shown in FIG. 3 takes into consideration the negative pressure of the brake booster BB in applying the concept shown in FIG. 2 to an actual brake control device. The stroke-corresponding target wheel cylinder hydraulic pressure calculation unit 201 calculates a stroke-corresponding target wheel cylinder hydraulic pressure P1 * corresponding to the stroke amount STR detected by the stroke sensor 17. In the target master cylinder hydraulic pressure calculation unit 202, the target master cylinder hydraulic pressure Pmc * becomes higher as the stroke amount STR detected by the stroke sensor 17 and the negative pressure of the brake booster BB detected by the negative pressure sensor 18 increase. Set The deviation calculation unit 203 calculates a deviation ΔPmc between the target master cylinder hydraulic pressure Pmc * and the master cylinder hydraulic pressure Pmc detected by the master cylinder hydraulic pressure sensor 40. Master cylinder liquid pressure corresponding target wheel cylinder liquid pressure calculation unit 204 multiplies deviation ΔPmc by conversion coefficient K1 to calculate master cylinder liquid pressure corresponding target wheel cylinder liquid pressure P2 *. The target wheel cylinder hydraulic pressure calculation unit 205 adds the target wheel cylinder hydraulic pressure P1 * corresponding to the stroke and the target wheel cylinder hydraulic pressure P2 * corresponding to the master cylinder hydraulic pressure, and calculates the final target wheel cylinder hydraulic pressure P *. calculate.

Here, that the target wheel hydraulic pressure corresponding to master cylinder hydraulic pressure P2 * is small means that the deviation ΔPmc between the target master cylinder hydraulic pressure Pmc * and the master cylinder hydraulic pressure Pmc becomes negative. That is, it is a case where it is necessary to raise master cylinder liquid pressure Pmc. In order to raise the master cylinder hydraulic pressure Pmc, it is necessary to weaken the action of pumping the brake fluid from the master cylinder M / C to the wheel cylinder W / C side by the pump P (or to stop the pump P). Therefore, the amount of subtraction from the target foil cylinder hydraulic pressure P1 * corresponding to the stroke becomes larger (the amount of addition becomes negative) as the target wheel cylinder hydraulic pressure P2 * corresponding to the master cylinder hydraulic pressure decreases. As a result, the final target wheel cylinder hydraulic pressure P * becomes smaller, and the pressure increasing action by the pump P is weakened. Therefore, the phenomenon in which the brake pedal BP is sucked can be suppressed, and a good pedal feeling can be obtained.

On the other hand, that the target wheel hydraulic pressure corresponding to master cylinder hydraulic pressure P2 * is large means that the deviation ΔPmc between the target master cylinder hydraulic pressure Pmc * and the master cylinder hydraulic pressure Pmc is positive. That is, there is no need to raise the master cylinder hydraulic pressure Pmc so much. In order to suppress the rise of the master cylinder hydraulic pressure Pmc, it is necessary to pump up the brake fluid from the master cylinder M / C to the wheel cylinder W / C side by the pump P. Therefore, the configuration is such that the addition amount to the stroke-corresponding target wheel cylinder hydraulic pressure P1 * is increased as the target wheel cylinder liquid pressure P2 * corresponding to the master cylinder hydraulic pressure is larger. As a result, the final target wheel cylinder hydraulic pressure P * increases, and the pressure increasing action of the pump P is intensified. Thus, brake assist control can be realized in which the pedal feeling is secured according to the negative pressure. Therefore, the plate depressing phenomenon of the brake pedal BP can be suppressed, and a good pedal feeling can be obtained.

As described above, in the first embodiment, the following advantages can be obtained.
(1-1) Stroke sensor 17 (stroke calculation unit) that calculates the operation stroke of the driver's brake pedal, and master cylinder liquid pressure sensor 40 (master cylinder liquid pressure calculation that calculates the liquid pressure Pmc of the master cylinder M / C And a target wheel cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure set according to the stroke corresponding target wheel cylinder hydraulic pressure P1 * set according to the calculated operation stroke and the calculated master cylinder hydraulic pressure Pmc P2 * and a pump P that sucks in brake fluid from the master cylinder M / C and boosts the wheel cylinder hydraulic pressure so as to achieve target wheel cylinder hydraulic pressure, and the target wheel cylinder hydraulic pressure P * corresponds to the stroke A brake control device, which is calculated based on a target wheel cylinder hydraulic pressure P1 * and a target wheel hydraulic pressure corresponding to a master cylinder hydraulic pressure P2 *. Therefore, a good pedal feeling can be obtained.

(2-2) In the brake control device described in (1-1) above, the target wheel cylinder hydraulic pressure Pmc * corresponds to the target wheel cylinder hydraulic pressure P1 * corresponding to the stroke and the target wheel cylinder hydraulic pressure P2 * corresponding to the master cylinder hydraulic pressure. The brake control apparatus characterized by adding and calculating (refer FIG. 2). Therefore, a good pedal feeling can be obtained.

(3-3) The brake control device according to (1-1), further including: a brake booster BB (booster) for amplifying a driver's brake pedal operation force; A brake control device (see FIG. 3), which is calculated based on the negative pressure (amplification characteristic) of S, the calculated stroke amount STR (operation stroke), and the calculated hydraulic pressure Pmc of the master cylinder. By considering the negative pressure which is the amplification characteristic of the brake booster BB, a better pedal feeling can be obtained. The brake booster BB may be the negative pressure booster of the first embodiment, or may be an electromagnetic booster that assists the operating force of the brake pedal BP by electrical control. In addition, when an electromagnetic booster is employ | adopted, a favorable pedal feeling can be obtained by correct | amending not with a negative pressure but with an electromagnetic force.

(4-4) In the brake control device according to (3-3), the brake booster BB is a negative pressure booster that amplifies the brake pedal operating force by using a negative pressure generated by an engine. Brake control device. Therefore, the present invention can be applied to a vehicle equipped with a negative pressure booster that is often mounted on existing vehicles. In addition, even when the negative pressure is unstable, a good pedal feeling can be obtained.

(5-7) The pump P which sucks in the brake fluid from the master cylinder M / C and increases the wheel cylinder hydraulic pressure, and the stroke sensor 17 (stroke calculation) which calculates the stroke amount STR (operation stroke) of the brake pedal BP of the driver. Stroke target target wheel cylinder hydraulic pressure P1 * for assisting the pressure increase of the wheel cylinder hydraulic pressure by the pump P to achieve the target wheel cylinder hydraulic pressure P * set according to the calculated stroke amount STR (Basic assist amount) and target wheel cylinder hydraulic pressure calculation unit 103 (assist amount correction unit) for correcting the target wheel cylinder hydraulic pressure P1 * corresponding to a stroke, which is the basic assist amount, and the hydraulic pressure of the master cylinder M / C Master cylinder hydraulic pressure sensor 40 (master cylinder hydraulic pressure calculation unit), the target wheel cylinder hydraulic pressure calculation unit 103 calculates the calculated stroke amount STR, and The target wheel cylinder hydraulic pressure corrected for stroke based on the hydraulic pressure Pmc of the master cylinder and the corrected target wheel cylinder hydraulic pressure is set as the set target wheel cylinder hydraulic pressure P *. Brake control apparatus. Therefore, when assisting the pressure increase of the wheel cylinder hydraulic pressure, a good pedal feeling can be obtained.

(6-8) The brake control device according to (5-7), further including: a brake booster BB (booster) for amplifying the brake pedal operation force of the driver, and the target wheel cylinder hydraulic pressure calculation unit 103 A brake control apparatus characterized by correcting a stroke-corresponding target wheel cylinder hydraulic pressure P1 * based on a negative pressure (amplification characteristic) of BB, a calculated stroke amount STR, and a calculated hydraulic pressure Pmc of a master cylinder. . By considering the negative pressure which is the amplification characteristic of the brake booster BB, a better pedal feeling can be obtained. The brake booster BB may be the negative pressure booster of the first embodiment, or may be an electromagnetic booster that assists the operating force of the brake pedal BP by electrical control. In addition, when an electromagnetic booster is employ | adopted, a favorable pedal feeling can be obtained by correct | amending not with a negative pressure but with an electromagnetic force.

(7-9) In the brake control device according to (6-8), the brake booster BB is a negative pressure booster that amplifies the brake pedal operating force by using the negative pressure generated by the engine. Brake control device. Therefore, the present invention can be applied to a vehicle equipped with a negative pressure booster that is often mounted on existing vehicles. In addition, even when the negative pressure is unstable, a good pedal feeling can be obtained.

(8-10) In the brake control device according to (7-9), the target wheel cylinder hydraulic pressure calculation unit 205 (assist amount correction unit) calculates the target master cylinder hydraulic pressure Pmc * with respect to the calculated stroke amount STR. Calculate (target master cylinder hydraulic pressure calculation unit 202), and correct the target wheel cylinder hydraulic pressure based on the difference between the calculated target master cylinder hydraulic pressure Pmc * and the calculated master cylinder hydraulic pressure Pmc (master cylinder hydraulic pressure A corresponding target wheel cylinder hydraulic pressure calculation unit 204). Therefore, the target wheel cylinder fluid pressure can be achieved while securing an appropriate master cylinder fluid pressure, and a good pedal feeling can be obtained.

(9-13) From driver's brake pedal BP stroke amount STR (operation stroke) calculated, target wheel cylinder hydraulic pressure P * set according to the calculated stroke amount STR, and from master cylinder M / C A pump P that sucks the brake fluid and increases the wheel cylinder fluid pressure so that the target wheel cylinder fluid pressure P * is achieved, and a master cylinder fluid pressure sensor 40 that calculates the fluid pressure of the master cylinder M / C (master cylinder fluid pressure calculation And a target master cylinder hydraulic pressure calculation unit 202 that calculates a target master cylinder hydraulic pressure Pmc * that is calculated based on the calculated stroke amount STR; On the other hand, when the calculated master cylinder hydraulic pressure Pmc becomes high, the master cylinder hydraulic pressure is reduced (hereinafter referred to as a master cylinder hydraulic pressure control unit). Therefore, when the master cylinder hydraulic pressure Pmc is high, the master cylinder hydraulic pressure is reduced, so that it is possible to obtain a good pedal feeling by avoiding the plate stepping phenomenon.

(10-14) In the brake control device according to (9-13), the master cylinder hydraulic pressure control unit controls the target wheel cylinder hydraulic pressure calculation unit 205 to calculate the stroke amount STR and the master cylinder calculated. Target wheel cylinder hydraulic pressure P * is corrected based on the hydraulic pressure Pmc of the target (target wheel cylinder hydraulic pressure correction unit), and the pump drive amount is determined so that the corrected target wheel cylinder hydraulic pressure P * is achieved. A brake control device characterized by reducing master cylinder fluid pressure Pmc by sucking out brake fluid in a master cylinder. Therefore, the master cylinder hydraulic pressure Pmc can be reduced by enhancing the pressure increasing action of the pump P, and a good pedal feeling can be obtained while avoiding the plate stepping phenomenon.

(11-15) In the brake control device described in (9-14) above, the master cylinder hydraulic pressure control unit is configured to calculate the target wheel cylinder based on the calculated stroke amount STR and the calculated hydraulic pressure Pmc of the master cylinder. The fluid pressure P * is corrected (corresponding to the target wheel cylinder fluid pressure calculation unit 205), and the corrected target wheel cylinder fluid pressure P * is set as the set target wheel cylinder fluid pressure, and the brake fluid in the master cylinder is sucked by the pump P A brake control apparatus characterized by reducing master cylinder hydraulic pressure Pmc. Therefore, since the target wheel cylinder hydraulic pressure P * is corrected based on the master cylinder hydraulic pressure Pmc, a good pedal feeling can be obtained while avoiding the plate stepping phenomenon.

Example 2 Next, Example 2 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 4 is a block diagram of a brake control device according to a second embodiment. In the first embodiment, the pressure control reservoir 13 provided with the check valve 16 was provided. On the other hand, in the second embodiment, in place of the pressure control reservoir 13,

reservoirs

130S and 130P (hereinafter collectively referred to as a reservoir 130) not having the check valve 16 are provided, and a master cylinder M / C The difference is that gate-in

valves

50S and 50P (hereinafter collectively referred to as gate-in valve 50) are provided on the pipe line 11 connecting the suction side of the pump P. The gate-in valve 50 is a normally closed type that closes when not energized. Further, the first check valve 30S which allows the flow of the brake fluid from the reservoir 130 to the suction side of the pump P on the conduit 12 and prohibits the flow of the brake fluid from the suction side of the pump P to the reservoir 130 side, A second check valve disposed in series with the first check valve 30 between 30P (hereinafter collectively referred to as the first check valve 30) and the first check valve 30 and the suction side of the pump P. 31S and 31P (hereinafter collectively referred to as the second check valve 31). The conduit 11 is connected between the first check valve 30 and the second check valve 31. Even if the gate-in valve 50 is opened, the brake fluid does not flow into the reservoir 130 from the master cylinder M / C side. Is configured.

At the time of brake assist control, the gate-in valve 50 is opened, and the driving state of the pump P is controlled based on the target wheel cylinder hydraulic pressure P * and the target master cylinder hydraulic pressure Pmc * as in the first embodiment. Supply brake fluid from the M / C side to the wheel cylinder W / C side. Here, in the second embodiment, when the actual master cylinder hydraulic pressure Pmc becomes larger than the master cylinder hydraulic pressure Pmc * by a predetermined value or more, the solenoid out valve 15 is opened, and the wheel cylinder W / C is switched to the reservoir 130. Allow the brake fluid to drain. Thereby, the brake fluid pumped out from the master cylinder M / C by the pump P is increased, and the master cylinder hydraulic pressure Pmc is decreased to achieve the target master cylinder hydraulic pressure Pmc *. Thus, in the second embodiment, in addition to the same effects as the first embodiment, the following effects can be obtained.

(12-16) In the brake control device according to (9-13) above, the pipe line 14 (decompression oil path) connecting the wheel cylinder W / C and the reservoir 130 and the solenoid out valve provided in the pipe line 14 The master cylinder fluid pressure control unit opens the solenoid out valve 15 to reduce the wheel cylinder fluid pressure, and reduces the pressure in the master cylinder M / C to the wheel cylinder W / C that has been reduced in pressure. And a master cylinder hydraulic pressure Pmc is reduced. That is, by operating the solenoid out valve 15, a good pedal feeling can be obtained while avoiding the plate stepping phenomenon.

Example 3 Next, Example 3 will be described. The basic configuration is the same as that of the second embodiment, so only the differences will be described. FIG. 5 is a block diagram of a brake control device according to a third embodiment. In the second embodiment, the first check valve 30 is provided to prevent the brake fluid of the master cylinder M / C from flowing into the reservoir 130. On the other hand, in Example 3, the point which eliminated the 1st check valve 30 differs. The conduit 11 is connected to the conduit 12 closer to the reservoir 130 than the second check valve 31. Pipes on the pump P side from this connection point are suction oil path portions 12S1 and 12P1, and pipes on the reservoir 130 side from the connection point are pressure reduction oil path portions 12S2 and 12P2.

In the third embodiment, since the brake fluid can be directly supplied from the master cylinder M / C to the reservoir 130, it is not necessary to open the solenoid out valve 15 as in the second embodiment. When the driving amount of the pump P is smaller than the driving amount according to the driver's brake pedal operation, and the master cylinder hydraulic pressure Pmc becomes high, the hydraulic pressure of the suction oil passage portions 12S1, 12P1 becomes high. Then, the brake fluid automatically flows into the reservoir 130 through the pressure reducing oil passage portions 12S2 and 12P2, and the pedal stroke can be secured. Therefore, the board stepping phenomenon can be suppressed.

(13-17) In the brake control device described in (9-13) above, the pipe line 1 (first oil path) connecting the master cylinder M / C and the wheel cylinder W / C and the pipe line 1 are branched The conduit 11 (second oil passage) and the conduit 11 are provided with suction oil passage portions 12S1 and 12P1 connected to the pump P and pressure reducing oil passage portions 12S2 and 12P2 connected to the reservoir 130, and the inside of the master cylinder M / C The brake control device is characterized in that the brake fluid is supplied to the pump P and the reservoir 130 by the pipe line 11. When the master cylinder hydraulic pressure Pmc rises, the brake fluid in the master cylinder M / C automatically flows into the reservoir 130, so that the plate stepping phenomenon can be prevented.

Example 4 Next, Example 4 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 6 is a control block diagram showing a control configuration of brake assist control according to a fourth embodiment. The brake assist control configuration of the fourth embodiment includes the storage device 301 formed of a non-volatile memory capable of retaining information even when the power is off. The storage device 301 stores the signal from the ignition switch IGN, the stroke amount STR output from the stroke sensor 17, and the target wheel cylinder hydraulic pressure P * with respect to the stroke amount STR. In other words, the stroke corresponding target wheel cylinder hydraulic pressure P1 * is corrected according to the negative pressure of the brake booster BB and the master cylinder hydraulic pressure Pmc, and the corrected final target wheel cylinder hydraulic pressure P * is calculated as the stroke amount STR And store it in correspondence.

Normally, when the ignition switch IGN is turned off, the values in each control configuration are initialized. Therefore, when the ignition switch IGN is turned on next time, it is necessary to read the negative pressure and the master cylinder pressure Pmc again and calculate the final target wheel cylinder hydraulic pressure P * corrected thereafter. Therefore, there is a possibility that a delay may occur before outputting the appropriate target wheel cylinder hydraulic pressure P *. Therefore, the correspondence relationship between the stroke amount STR and the target wheel cylinder hydraulic pressure P * stored in the previous control is stored in the storage device 301. Then, when the ignition switch IGN is switched from OFF to ON, the stored target wheel cylinder hydraulic pressure P * corresponding to the stroke amount STR output by the stroke sensor 17 is output as an initial value. Thus, appropriate control can be performed immediately after the ignition switch IGN is turned on. After a predetermined period has elapsed since the ignition switch IGN was turned on, the control is switched to normal control processing.

As described above, in the fourth embodiment, the following effects can be obtained. (14-5) The brake control device according to (1-1) includes the storage device 301 (target wheel cylinder hydraulic pressure storage unit) for storing the calculated target wheel cylinder hydraulic pressure P *, and the pump P A brake control apparatus characterized by increasing a wheel cylinder hydraulic pressure so as to achieve a target wheel cylinder hydraulic pressure stored. Therefore, by using the stored target wheel cylinder hydraulic pressure, control can be performed without waiting for calculation processing, and a decrease in control responsiveness can be suppressed. In the fourth embodiment, the value stored only when the ignition switch IGN changes from OFF to ON is used. However, once correction control is performed, a predetermined change such as, for example, aging does not occur. Control may be performed continuously using the value of the storage device 301 for a period (for a predetermined number of days or a predetermined travel distance).
(15-6) The brake control device according to (14-5), wherein the storage device 301 is a non-volatile memory. Therefore, when the ignition switch IGN is switched from OFF to ON next time, brake assist control can be started without waiting for calculation processing based on the master cylinder pressure.

(16-11) In the brake control device according to (5-7), the storage device 301 (target wheel cylinder hydraulic pressure storage unit) for storing the calculated target wheel cylinder hydraulic pressure P * is provided, and the target wheel cylinder A brake control device characterized in that the hydraulic pressure calculation unit 103 (assist amount correction unit) determines the drive amount of the pump P so as to be the target wheel cylinder hydraulic pressure stored after correction. Therefore, by using the stored target wheel cylinder hydraulic pressure, control can be performed without waiting for correction processing, and a decrease in control responsiveness can be suppressed.
(17-12) A brake control apparatus according to the above (16-11), wherein the storage device 301 is a non-volatile memory. Therefore, when the ignition switch IGN is switched from OFF to ON next time, brake assist control can be started without waiting for correction based on the master cylinder pressure.

Below, an example of the technical thought grasped from an example is explained.
(A1) a brake control device,
A stroke calculation unit that calculates an operation stroke of a driver's brake pedal;
A master cylinder fluid pressure calculation unit that calculates the fluid pressure of the master cylinder;
A stroke corresponding target wheel cylinder hydraulic pressure calculating unit that calculates a stroke corresponding target wheel cylinder hydraulic pressure according to the calculated operation stroke;
A target wheel hydraulic pressure corresponding target wheel cylinder hydraulic pressure calculation unit for calculating a target wheel hydraulic pressure corresponding to the master cylinder hydraulic pressure according to the calculated master cylinder hydraulic pressure;
A target wheel cylinder hydraulic pressure calculation unit that calculates a target wheel cylinder hydraulic pressure based on the stroke target wheel cylinder hydraulic pressure and the target cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure, and a pump are driven to generate the master cylinder. A pump drive unit which sucks in the brake fluid from the pump by the pump and pressurizes the fluid pressure of the wheel cylinder so as to achieve the target wheel cylinder fluid pressure;
Brake control device comprising:
(A2) In the brake control device according to (a1),
The brake control device, wherein the target wheel cylinder hydraulic pressure calculation unit calculates the target wheel cylinder hydraulic pressure by adding the target wheel cylinder hydraulic pressure corresponding to the stroke and the target wheel cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure. .
(A3) In the brake control device according to (a1) or (a2),
A booster that amplifies the driver's brake pedal operation force is connected to the master cylinder,
The target cylinder hydraulic pressure corresponding target cylinder hydraulic pressure calculation unit for the master cylinder hydraulic pressure is the target corresponding to the master cylinder hydraulic pressure based on the amplification characteristic of the booster, the calculated operation stroke, and the calculated hydraulic pressure of the master cylinder. A brake control device that calculates the wheel cylinder fluid pressure.
(A4) In the brake control device according to (a3),
The brake control device, wherein the booster is a negative pressure booster that amplifies the brake pedal operating force using a negative pressure generated by an engine.
(A5) In the brake control device according to any one of (a1) to (a4),
A target wheel cylinder hydraulic pressure storage unit that stores the calculated operation stroke in correspondence with the calculated target wheel cylinder hydraulic pressure;
The brake control device, wherein the pump drive unit increases the fluid pressure of the wheel cylinder so as to achieve the stored target wheel cylinder fluid pressure corresponding to the calculated operation stroke.
(A6) In the brake control device according to (a5),
The brake control device, wherein the target wheel cylinder hydraulic pressure storage unit is a non-volatile memory.
(A7) In the brake control device according to any one of (a1) to (a6),
The hydraulic control unit further includes a hydraulic control unit that connects the wheel silider and the master cylinder, and the hydraulic control unit includes the pump.
A brake control device, wherein the suction side of the pump is connected to the master cylinder via a pressure control reservoir including a pressure sensitive check valve, and the discharge side of the pump is connected to the wheel cylinder.
(A8) In the brake control device according to any one of (a1) to (a6),
The target wheel cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure calculates a target master cylinder hydraulic pressure according to the calculated operation stroke,
A pressure reducing oil passage connecting the wheel cylinder and the reservoir;
A pressure reducing valve provided in the pressure reducing oil passage;
When the calculated master cylinder fluid pressure becomes larger than the target master cylinder fluid pressure by a predetermined value or more, the pressure reducing valve is opened to reduce the wheel cylinder fluid pressure, and the wheel is decompressed from within the master cylinder And a master cylinder hydraulic pressure control unit that supplies brake fluid to a cylinder and reduces the master cylinder hydraulic pressure.
(A9) In the brake control device according to any one of (a1) to (a6),
A first oil passage connecting the master cylinder and the wheel cylinder;
And a second oil passage branched from the first oil passage,
The second oil passage includes a suction oil passage connected to the pump and a pressure reduction oil passage connected to a reservoir.
The brake control device, wherein the brake fluid in the master cylinder is supplied to the pump and the reservoir by the second oil passage.

(A10) a brake control device,
A pump that sucks in brake fluid from the master cylinder to increase the wheel cylinder fluid pressure;
A stroke calculation unit that calculates an operation stroke of a driver's brake pedal;
A master cylinder fluid pressure calculation unit that calculates the fluid pressure of the master cylinder;
An assist amount calculation unit that calculates a basic assist amount for assisting the pressure increase of the wheel cylinder hydraulic pressure by the pump, and calculates the basic assist amount based on the calculated operation stroke; ,
A target wheel cylinder hydraulic pressure calculating unit that calculates a target wheel cylinder hydraulic pressure by correcting the basic assist amount based on the operation stroke and the calculated hydraulic pressure of the master cylinder;
A pump drive unit configured to set a drive amount of the pump such that a fluid pressure of the wheel cylinder becomes the target wheel cylinder fluid pressure.
(A11) In the brake control device according to (a10),
A booster that amplifies the driver's brake pedal operation force is connected to the master cylinder,
The target wheel cylinder hydraulic pressure calculation unit corrects the basic assist amount based on the amplification characteristic of the booster, the calculated operation stroke, and the calculated hydraulic pressure of the master cylinder.
(A12) In the brake control device according to (a11),
The brake control device, wherein the booster is a negative pressure booster that amplifies the brake pedal operating force using a negative pressure generated by an engine.
(A13) In the brake control device according to (a10),
The target wheel cylinder hydraulic pressure calculation unit calculates a target master cylinder hydraulic pressure for the calculated operation stroke, and based on the difference between the calculated target master cylinder hydraulic pressure and the calculated master cylinder hydraulic pressure. A brake control device that corrects the assist amount and calculates the target wheel cylinder hydraulic pressure.
(A14) In the brake control device according to any one of (a10) to (a13),
A target wheel cylinder hydraulic pressure storage unit that stores the calculated operation stroke in correspondence with the corrected target wheel cylinder hydraulic pressure;
The pump control unit determines the drive amount of the pump so that the fluid pressure of the wheel cylinder becomes the corresponding stored target wheel cylinder fluid pressure according to the calculated operation stroke.
(A15) In the brake control device according to (a14),
The brake control device, wherein the target wheel cylinder hydraulic pressure storage unit is a non-volatile memory.

(A16) a brake control device,
A target wheel cylinder hydraulic pressure calculation unit that calculates an operation stroke of a driver's brake pedal and calculates a target wheel cylinder hydraulic pressure according to the calculated operation stroke;
A pump drive unit which drives a pump, sucks a brake fluid from the master cylinder by the pump, and increases the hydraulic pressure of the wheel cylinder so as to achieve the target wheel cylinder hydraulic pressure;
A master cylinder fluid pressure calculation unit that calculates the fluid pressure of the master cylinder;
A target master cylinder hydraulic pressure calculating unit that calculates a target master cylinder hydraulic pressure calculated based on the calculated operation stroke;
The drive amount of the pump is determined so that the fluid pressure of the wheel cylinder becomes the target wheel cylinder fluid pressure, and the master cylinder fluid calculated with respect to the target master cylinder fluid pressure during pressure increase by the pump A master cylinder fluid pressure control unit that reduces the master cylinder fluid pressure when the pressure increases;
The brake control apparatus characterized by having.
(A17) In the brake control device according to (a16),
The master cylinder hydraulic pressure control unit includes a target wheel cylinder hydraulic pressure correction unit that corrects the target wheel cylinder hydraulic pressure based on the calculated operation stroke and the calculated hydraulic pressure of the master cylinder.
The master cylinder fluid pressure control unit determines the driving amount of the pump so as to be the corrected target wheel cylinder fluid pressure, and sucks out the brake fluid in the master cylinder by the pump to thereby obtain the master cylinder fluid pressure. A brake control unit that depressurizes.
(A18) In the brake control device according to (16),
The master cylinder hydraulic pressure control unit corrects the target wheel cylinder hydraulic pressure based on the calculated operation stroke and the calculated hydraulic pressure of the master cylinder, and the hydraulic pressure of the wheel cylinder is corrected after the correction. A brake control device, wherein a drive amount of the pump is determined so as to reach a target wheel cylinder hydraulic pressure, and brake fluid in the master cylinder is drawn by the pump to reduce the master cylinder hydraulic pressure.
(A19) In the brake control device according to (a16),
A pressure reducing oil passage connecting the wheel cylinder and the reservoir;
A pressure reducing valve provided in the pressure reducing oil passage;
The master cylinder fluid pressure control unit opens the pressure reducing valve to reduce the wheel cylinder fluid pressure, supplies brake fluid to the wheel cylinder that has been reduced in pressure from the master cylinder, and reduces the fluid pressure of the master cylinder. , Brake control device.
(A20) In the brake control device according to (a16),
A first oil passage connecting the master cylinder and the wheel cylinder;
And a second oil passage branched from the first oil passage,
The second oil passage includes a suction oil passage connected to the pump and a pressure reduction oil passage connected to a reservoir.
The brake control device, wherein the brake fluid in the master cylinder is supplied to the pump and the reservoir by the second oil passage.

According to the above embodiment, a good pedal feeling can be obtained.

While only certain embodiments of the invention have been described above, it will be appreciated that various changes and modifications may be made to the illustrated embodiments without departing substantially from the novel teachings and advantages of the invention. Will be readily understood by those skilled in the art. Accordingly, it is intended that the embodiments added with such alterations or improvements are also included in the technical scope of the present invention.
Although the embodiments of the present invention have been described above based on several examples, the above-described embodiments of the present invention are for the purpose of facilitating the understanding of the present invention, and are not intended to limit the present invention. . The present invention can be modified and improved without departing from the gist thereof, and the present invention naturally includes the equivalents thereof. In addition, any combination or omission of each component described in the claims and the specification is possible within a range in which at least a part of the above-mentioned problems can be solved, or in a range that exerts at least a part of the effect. It is.

This application claims the priority based on Japanese Patent Application No. 2014-183075 filed on Sep. 9, 2014. The disclosure of Japanese Patent Application No. 2014-183075 filed on Sep. 9, 2014, including the specification, claims, drawings and abstract is incorporated herein by reference in its entirety.
The entire disclosure, including the specification, claims, drawings and abstract of JP 10-329678 A, is incorporated herein by reference in its entirety.

Reference Signs List 1 pipe 3 gate out valve 5 check valve 6 solenoid in valve 11 pipe 12 pipe 12S1, 12P1 suction oil path 12S2, 12P2 pressure reducing oil path 13 pressure control reservoir 14 pipe 15 solenoid out valve 16 check valve 17 stroke Sensor 18 Negative pressure sensor 20 Motor drive unit 30 First check valve 31 Second check valve 40 Master cylinder hydraulic pressure sensor 50 Gate in valve 101 Stroke corresponding target wheel cylinder hydraulic pressure calculation unit 102 Master cylinder hydraulic pressure corresponding target foil cylinder hydraulic pressure Calculation unit 103 Target wheel cylinder hydraulic pressure calculation unit 130 Reservoir 201 Target wheel cylinder hydraulic pressure calculation unit 202 corresponding to stroke Target master cylinder hydraulic pressure calculation unit 203 Deviation calculation unit 204 Target wheel cylinder hydraulic pressure calculation unit 205 corresponding to master cylinder hydraulic pressure Target wheel cylinder pressure calculating section 301 storage device BB brake booster BCU brake control unit BP brake pedal HU fluid pressure control unit IGN ignition switch M the motor M / C master cylinder P Pump W / C wheel cylinder RSV reservoir tank

Claims

A brake control device,
A stroke calculation unit that calculates an operation stroke of a driver's brake pedal;
A master cylinder fluid pressure calculation unit that calculates the fluid pressure of the master cylinder;
A stroke corresponding target wheel cylinder hydraulic pressure calculating unit that calculates a stroke corresponding target wheel cylinder hydraulic pressure according to the calculated operation stroke;
A target wheel hydraulic pressure corresponding target wheel cylinder hydraulic pressure calculation unit for calculating a target wheel hydraulic pressure corresponding to the master cylinder hydraulic pressure according to the calculated master cylinder hydraulic pressure;
A target wheel cylinder hydraulic pressure calculation unit that calculates a target wheel cylinder hydraulic pressure based on the stroke target wheel cylinder hydraulic pressure and the target cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure, and a pump are driven to generate the master cylinder. A pump drive unit which sucks in the brake fluid from the pump by the pump and pressurizes the fluid pressure of the wheel cylinder so as to achieve the target wheel cylinder fluid pressure;
Brake control device comprising:
In the brake control device according to claim 1,
The brake control device, wherein the target wheel cylinder hydraulic pressure calculation unit calculates the target wheel cylinder hydraulic pressure by adding the target wheel cylinder hydraulic pressure corresponding to the stroke and the target wheel cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure. .
In the brake control device according to claim 1,
A booster that amplifies the driver's brake pedal operation force is connected to the master cylinder,
The target cylinder hydraulic pressure corresponding target cylinder hydraulic pressure calculation unit for the master cylinder hydraulic pressure is the target corresponding to the master cylinder hydraulic pressure based on the amplification characteristic of the booster, the calculated operation stroke, and the calculated hydraulic pressure of the master cylinder. A brake control device that calculates the wheel cylinder fluid pressure.
In the brake control device according to claim 3,
The brake control device, wherein the booster is a negative pressure booster that amplifies the brake pedal operating force using a negative pressure generated by an engine.
In the brake control device according to claim 1,
A target wheel cylinder hydraulic pressure storage unit that stores the calculated operation stroke in correspondence with the calculated target wheel cylinder hydraulic pressure;
The brake control device, wherein the pump drive unit increases the fluid pressure of the wheel cylinder so as to achieve the stored target wheel cylinder fluid pressure corresponding to the calculated operation stroke.
In the brake control device according to claim 5,
The brake control device, wherein the target wheel cylinder hydraulic pressure storage unit is a non-volatile memory.
In the brake control device according to claim 1,
The hydraulic control unit further includes a hydraulic control unit that connects the wheel silider and the master cylinder, and the hydraulic control unit includes the pump.
A brake control device, wherein the suction side of the pump is connected to the master cylinder via a pressure control reservoir including a pressure sensitive check valve, and the discharge side of the pump is connected to the wheel cylinder.
In the brake control device according to claim 1,
The target wheel cylinder hydraulic pressure corresponding to the master cylinder hydraulic pressure calculates a target master cylinder hydraulic pressure according to the calculated operation stroke,
A pressure reducing oil passage connecting the wheel cylinder and the reservoir;
A pressure reducing valve provided in the pressure reducing oil passage;
When the calculated master cylinder fluid pressure becomes larger than the target master cylinder fluid pressure by a predetermined value or more, the pressure reducing valve is opened to reduce the wheel cylinder fluid pressure, and the wheel is decompressed from within the master cylinder And a master cylinder hydraulic pressure control unit that supplies brake fluid to a cylinder and reduces the master cylinder hydraulic pressure.
In the brake control device according to claim 1,
A first oil passage connecting the master cylinder and the wheel cylinder;
And a second oil passage branched from the first oil passage,
The second oil passage includes a suction oil passage connected to the pump and a pressure reduction oil passage connected to a reservoir.
The brake control device, wherein the brake fluid in the master cylinder is supplied to the pump and the reservoir by the second oil passage.
A brake control device,
A pump that sucks in brake fluid from the master cylinder to increase the wheel cylinder fluid pressure;
A stroke calculation unit that calculates an operation stroke of a driver's brake pedal;
A master cylinder fluid pressure calculation unit that calculates the fluid pressure of the master cylinder;
An assist amount calculation unit that calculates a basic assist amount for assisting the pressure increase of the wheel cylinder hydraulic pressure by the pump, and calculates the basic assist amount based on the calculated operation stroke; ,
A target wheel cylinder hydraulic pressure calculating unit that calculates a target wheel cylinder hydraulic pressure by correcting the basic assist amount based on the operation stroke and the calculated hydraulic pressure of the master cylinder;
A pump drive unit configured to set a drive amount of the pump such that a fluid pressure of the wheel cylinder becomes the target wheel cylinder fluid pressure.
In the brake control device according to claim 10,
A booster that amplifies the driver's brake pedal operation force is connected to the master cylinder,
The target wheel cylinder hydraulic pressure calculation unit corrects the basic assist amount based on the amplification characteristic of the booster, the calculated operation stroke, and the calculated hydraulic pressure of the master cylinder.
In the brake control device according to claim 11,
The brake control device, wherein the booster is a negative pressure booster that amplifies the brake pedal operating force using a negative pressure generated by an engine.
In the brake control device according to claim 10,
The target wheel cylinder hydraulic pressure calculation unit calculates a target master cylinder hydraulic pressure for the calculated operation stroke, and based on the difference between the calculated target master cylinder hydraulic pressure and the calculated master cylinder hydraulic pressure. A brake control device that corrects the assist amount and calculates the target wheel cylinder hydraulic pressure.
In the brake control device according to claim 10,
A target wheel cylinder hydraulic pressure storage unit that stores the calculated operation stroke in correspondence with the corrected target wheel cylinder hydraulic pressure;
The pump control unit determines the drive amount of the pump so that the fluid pressure of the wheel cylinder becomes the corresponding stored target wheel cylinder fluid pressure according to the calculated operation stroke.
In the brake control device according to claim 14,
The brake control device, wherein the target wheel cylinder hydraulic pressure storage unit is a non-volatile memory.
A brake control device,
A target wheel cylinder hydraulic pressure calculation unit that calculates an operation stroke of a driver's brake pedal and calculates a target wheel cylinder hydraulic pressure according to the calculated operation stroke;
A pump drive unit which drives a pump, sucks a brake fluid from the master cylinder by the pump, and increases the hydraulic pressure of the wheel cylinder so as to achieve the target wheel cylinder hydraulic pressure;
A master cylinder fluid pressure calculation unit that calculates the fluid pressure of the master cylinder;
A target master cylinder hydraulic pressure calculating unit that calculates a target master cylinder hydraulic pressure calculated based on the calculated operation stroke;
The drive amount of the pump is determined so that the fluid pressure of the wheel cylinder becomes the target wheel cylinder fluid pressure, and the master cylinder fluid calculated with respect to the target master cylinder fluid pressure during pressure increase by the pump A master cylinder fluid pressure control unit that reduces the master cylinder fluid pressure when the pressure increases;
The brake control apparatus characterized by having.
In the brake control device according to claim 16,
The master cylinder hydraulic pressure control unit includes a target wheel cylinder hydraulic pressure correction unit that corrects the target wheel cylinder hydraulic pressure based on the calculated operation stroke and the calculated hydraulic pressure of the master cylinder.
The master cylinder fluid pressure control unit determines the driving amount of the pump so as to be the corrected target wheel cylinder fluid pressure, and sucks out the brake fluid in the master cylinder by the pump to thereby obtain the master cylinder fluid pressure. A brake control unit that depressurizes.
In the brake control device according to claim 16,
The master cylinder hydraulic pressure control unit corrects the target wheel cylinder hydraulic pressure based on the calculated operation stroke and the calculated hydraulic pressure of the master cylinder, and the hydraulic pressure of the wheel cylinder is corrected after the correction. A brake control device, wherein a drive amount of the pump is determined so as to reach a target wheel cylinder hydraulic pressure, and brake fluid in the master cylinder is drawn by the pump to reduce the master cylinder hydraulic pressure.
In the brake control device according to claim 16,
A pressure reducing oil passage connecting the wheel cylinder and the reservoir;
A pressure reducing valve provided in the pressure reducing oil passage;
The master cylinder fluid pressure control unit opens the pressure reducing valve to reduce the wheel cylinder fluid pressure, supplies brake fluid to the wheel cylinder that has been reduced in pressure from the master cylinder, and reduces the fluid pressure of the master cylinder. , Brake control device.
In the brake control device according to claim 16,
A first oil passage connecting the master cylinder and the wheel cylinder;
And a second oil passage branched from the first oil passage,
The second oil passage includes a suction oil passage connected to the pump and a pressure reduction oil passage connected to a reservoir.
The brake control device, wherein the brake fluid in the master cylinder is supplied to the pump and the reservoir by the second oil passage.