KR101183285B1 - Vehicles hydraulic boost apparatus and method of controlling the same - Google Patents

Abstract

The present invention provides a brake pedal for instructing braking of a vehicle; Booster for boosting the pedal pedal effort; A master cylinder generating hydraulic pressure in response to the boosting force of the booster; A piston having a seal that maintains hermeticity with the master cylinder and moving in response to pressurization of the brake pedal; A pedal stroke detection unit detecting a pedal stroke of the brake pedal; Hydraulic power unit for adjusting the pressure of the booster; It is determined whether the target pressure of the master cylinder is changed based on the pedal stroke, and when the target pressure of the master cylinder is changed, the target pressure of the booster is calculated based on the target pressure of the master cylinder and the preset frictional force of the seal, and the calculated booster And a control unit for controlling the hydraulic power unit to generate a target pressure.
The present invention can generate an appropriate braking force when braking the vehicle can improve the stability. Accordingly, it is possible to improve braking performance and to reduce safety accidents.

Description

Vehicle hydraulic booster and method of controlling the same {Vehicles hydraulic boost apparatus and method of controlling the same}

The present invention relates to a vehicle hydraulic power booster and a control method thereof, and more particularly, to a vehicle hydraulic power booster and a control method for improving the braking control accuracy when the vehicle braking.

Hybrid vehicles and electric vehicles (electric vehicles) are next-generation environmental vehicles that are driven by driving the engine and the motor is equipped with a motor driven by receiving the electric energy stored in the engine and the battery which is an internal combustion engine.

Hybrid vehicles and electric vehicles perform braking by controlling the hydraulic pressure of the motor and the master cylinder, and these vehicles are equipped with an active hydraulic boost (AHB) to improve braking performance.

Here, the active hydraulic power booster (AHB) is a device that generates a braking force corresponding to the driver's braking intention by directly supplying the brake fluid charged at high pressure to the booster.

The active hydraulic power boost (AHB) device includes a master cylinder having a pedal simulator and a hydraulic power unit. Here, the pedal simulator generates a reaction force corresponding to the pedaling force of the brake pedal pressed by the driver, and the hydraulic power unit charges the brake fluid at a high pressure and supplies the pressure corresponding to the pedaling force of the brake pedal to the booster so that the master cylinder generates sufficient pressure. To be generated. At this time, the master cylinder supplies the generated pressure to the shock cylinder, and the wheel cylinder generates a braking force using the pressure supplied from the master cylinder.

Here, the pressure controlled by the hydraulic power unit (HPU) is the pressure of the booster, but the target braking pressure required by the actual driver is the pressure of the master cylinder.

Accordingly, the two pressures are different from each other by the frictional force generated in the seal for maintaining the airtightness of the booster and the master cylinder, and the direction of the frictional force is opposite to the direction of movement of the power piston in the booster.

Therefore, when the pressure of the booster is increased, the pressure of the master cylinder is formed lower than the pressure of the booster, and when the pressure of the booster is lowered, the pressure of the master cylinder is formed higher than the pressure of the booster.

Therefore, when the target pressure of the booster is set to the target pressure of the master cylinder, there is a problem in that a braking force suitable for the driver's request or regenerative braking control cannot be obtained.

An object of the present invention for solving the above problems is to adjust the pressure of the booster in response to the change in the pressure of the master cylinder to generate a braking force desired by the driver, and to improve the braking performance of the vehicle hydraulic power booster and its control To provide a way.

Vehicle hydraulic power supply apparatus according to an aspect of the present invention, the brake pedal for instructing the braking of the vehicle; Booster for boosting the pedal pedal effort; A master cylinder generating hydraulic pressure in response to the boosting force of the booster; A piston having a seal that maintains hermeticity with the master cylinder and moving in response to pressurization of the brake pedal; A pedal stroke detection unit detecting a pedal stroke of the brake pedal; Hydraulic power unit for adjusting the pressure of the booster; It is determined whether the target pressure of the master cylinder is changed based on the pedal stroke, and when the target pressure of the master cylinder is changed, the target pressure of the booster is calculated based on the target pressure of the master cylinder and the preset frictional force of the seal, and the calculated booster And a control unit for controlling the hydraulic power unit to generate a target pressure.

The control unit calculates the target pressure of the booster by adding the friction force of the seal to the target pressure of the master cylinder when the target pressure of the master cylinder increases.

The control unit calculates the target pressure of the booster by subtracting the frictional force of the seal from the target pressure of the master cylinder when the target pressure of the master cylinder decreases.

The control unit calculates a target braking force based on the pedal stroke, and calculates a target pressure of the master cylinder corresponding to the target braking force.

The control unit calculates the target braking force based on the pedal stroke, calculates the regenerative braking force generated by the braking motor, calculates the hydraulic braking force by subtracting the regenerative braking force from the target braking force, and target pressure of the master cylinder corresponding to the hydraulic braking force. To calculate.

According to another aspect of the present invention, there is provided a control method of a vehicle hydraulic power booster including: a brake pedal for instructing braking of a vehicle; a booster for boosting the pedal force of the brake pedal; a master cylinder for generating hydraulic pressure in response to the booster power; In the control method of the hydraulic power booster provided with a hydraulic power unit for adjusting the pressure of the booster, detecting the pedal stroke of the brake pedal corresponding to the pressurized state of the brake pedal, and determines whether the target pressure of the master cylinder changes based on the pedal stroke When the target pressure of the master cylinder changes, the target pressure of the booster is calculated on the basis of the target pressure of the master cylinder and the preset frictional force of the seal, and the driving of the hydraulic power unit is controlled to generate the calculated target pressure.

The target pressure of the booster is calculated by adding the friction force of the seal to the target pressure of the master cylinder when the target pressure of the master cylinder increases, and calculating the target pressure of the booster, and the target pressure of the master cylinder when the target pressure of the master cylinder decreases. The target pressure of the booster is calculated by subtracting the frictional force of the seal.

Generating a target pressure in the booster to supply the brake fluid of the booster, forming a target pressure in the master cylinder, supplying the brake fluid of the master cylinder to the wheel cylinder, and generating a target braking force in the wheel cylinder.

If the target pressure of the master cylinder fluctuates periodically, the method further includes setting a section in which fade out and fade in are performed.

The present invention can generate an appropriate braking force when braking the vehicle can improve the stability.

Accordingly, it is possible to improve braking performance and to reduce safety accidents.

1 is a block diagram of a vehicle hydraulic power booster according to an embodiment of the present invention.
2 is a detailed configuration diagram of a vehicle hydraulic power booster according to an embodiment of the present invention.
3 is a detailed configuration diagram of the brake actuation unit provided in the vehicle hydraulic power booster according to the embodiment of the present invention.
4 is a graph of pressure and pedal stroke over time in a vehicle hydraulic power booster according to an exemplary embodiment of the present invention.
5 is a control flowchart of a vehicle hydraulic power booster according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a vehicle hydraulic power booster according to an embodiment of the present invention, Figure 2 is a detailed configuration diagram of a vehicle hydraulic power booster according to an embodiment of the present invention, Figure 3 is a vehicle according to an embodiment of the present invention It is a detailed block diagram of the brake actuation part provided in the hydraulic power booster.

As shown in FIG. 1, the vehicle hydraulic power boosting device includes a wheel 10 provided to be rotatable in front, rear, left, and right sides of a vehicle, and a brake actuating unit 20 for generating a target braking force corresponding to the foot force of the brake pedal 21. And the hydraulic power unit 30 to charge the brake fluid at a high pressure and supply the brake fluid corresponding to the stepping force of the brake pedal 21 to the booster 22 so that the master cylinder 23 can generate sufficient pressure. And, the hydraulic pressure control unit 40 for adjusting the pressure by increasing or reducing the hydraulic pressure applied to the wheel cylinder 26 from the master cylinder 23, and the hydraulic braking force corresponding to the target braking force according to the braking intention of the driver is generated The control unit 50 to control the hydraulic power unit 30 and the hydraulic control unit 40 to include. The target braking force here is a hydraulic braking force.

When the regenerative braking is also performed, the vehicle hydraulic power boosting device generates the driving force and the regenerative braking force of the vehicle by generating the driving force and the regenerative braking force of the vehicle by forward / reversing the braking motor 65 and the braking motor 65 for regenerative braking. It further includes a regenerative braking unit 60 to perform. In this case, the controller 50 controls the hydraulic power unit 30, the hydraulic control unit 40, and the regenerative braking unit 60 to generate the regenerative braking force and the hydraulic braking force corresponding to the target braking force detected by the pedal stroke detection unit 27. To control. The target braking force is the sum of the regenerative braking force and the hydraulic braking force.

More specifically, as shown in FIG. 2, the brake actuation unit 20 pressurizes or depressurizes the driver so that the brake pedal 21 instructs braking of the vehicle and the pedal force of the brake pedal 21 are backed up. The booster 22, the master cylinder 23 for generating hydraulic pressure by the backing force of the booster 22, and the reservoir 24 for storing brake fluid connected to the master cylinder 23 and the hydraulic line L1. A pedal simulator 25 connected to the hydraulic power unit 30 and the hydraulic line L3 and generating a reaction force corresponding to the stepping force of the brake pedal pressed by the driver; The wheel cylinder 26 for converting the hydraulic action force supplied from the master cylinder 23 through the line L4 into mechanical force and the pedal stroke which is the mechanical momentum of the brake pedal 21 (position of the brake pedal) are detected. Pedal straw It includes a detection unit 27. Here, the hydraulic fluid of the low pressure brake flows (L1).

As shown in FIG. 3, the booster 22 includes a housing H for forming an appearance and a back force, and a piston PS provided in the housing H to move in response to the pressurization of the brake pedal 21. And a seal S provided in the piston PS to maintain airtightness with the master cylinder 23.

As shown in FIG. 2, the hydraulic power unit 30 is provided in the hydraulic line L3 between the reverser 24 and the pedal simulator 25 to detect the pressure of the pedal simulator 25. 31 and a cut valve 32 provided in the hydraulic line L3 between the reverser 24 and the pedal simulator 25 to regulate the supply of brake fluid between the reservoir 24 and the pedal simulator 25; A pump 33 for pumping and discharging the brake fluid of the reverser 24, a high pressure accumulator 34 for reducing the noise and pulsation of the brake fluid discharged from the pump 33 and temporarily storing the brake fluid, and a pump A high pressure accumulator pressure detector 35 provided in the hydraulic line L2 between the high pressure accumulator 34 and the hydraulic line L2 connected to the high pressure accumulator 34 and the booster provided in the hydraulic line L2 between the high pressure accumulator 34 and the high pressure accumulator 34. Hydraulic line (L4) threaded to (22) Is connected to the hydraulic valve L1 connected to the reservoir 24, the booster 22 connected to the reservoir 24, and the application valve 36 to control the brake fluid supply to the booster 22. A release valve 37 provided between the hydraulic lines L4 and opened when the brake pedal 21 is depressurized to adjust the brake fluid supply to the reservoir 24, and a booster pressure detector for detecting the pressure of the booster 22. (38). Here, the hydraulic line (L2) flows the high pressure brake fluid.

The hydraulic control unit 40 is connected to the master cylinder 23 and the hydraulic line L4 so that the brake fluid is supplied from the master cylinder 23, and the supplied brake fluid is adjusted to the wheel cylinder 26. .

The hydraulic control unit 40 is a hydraulic pump (not shown) for pumping the brake fluid of the reservoir 24 to supply to each wheel cylinder 26 side, and a low pressure accumulator for temporarily storing the brake fluid pumped by the hydraulic pump ( And a plurality of solenoid valves (not shown) for supplying the brake fluid supplied from the master cylinder 23 to the wheel cylinder 26 or returning to the reservoir 24.

The solenoid valve here is a reservoir 24, a master cylinder 23 and a wheel cylinder 26 A normal open solenoid valve (NO: Normal Open), which is provided in the hydraulic line (L4) therebetween and opens the valve flow path before being energized and closes the valve flow path when energized, the wheel cylinder 23, the low pressure accumulator (not shown), It is provided in the hydraulic line between the reservoir 24 and has a normal close solenoid valve (NC: Normal Close) which closes a valve flow path before it is energized, and opens a valve flow path when it is energized.

When the hydraulic braking force of the wheel cylinder 26 is increased, the hydraulic control unit 40 opens the normal open solenoid valve and drives the hydraulic pump according to the command of the controller 50 to control the normal fluid solenoid valve of the low pressure accumulator. Feed through the wheel cylinder 26 to increase the pressure of the wheel cylinder (26).

When the hydraulic braking force of the wheel cylinder 26 is reduced, the hydraulic controller 40 stops the hydraulic pump according to the command of the controller 50 and opens the normal closed solenoid valve to normalize the brake fluid of the wheel cylinder 26. The pressure in the wheel cylinder 26 is reduced by allowing the solenoid valve to return to the master cylinder 23. At this time, the brake fluid discharged from the wheel cylinder 26 may be temporarily stored in the low pressure accumulator.

When the proper pressure is applied to the wheel cylinder 26 through depressurization and increase in pressure, the hydraulic control unit 40 closes the normal open solenoid valve and the normal closed solenoid valve according to the command of the controller 50 to pressurize the pressure of the wheel cylinder 26. Keep it.

The controller 50 brakes the driver based on the pressure of the pedal simulator 25 transmitted from the pressure detector 31 of the pedal simulator 25 and the stroke of the brake pedal 21 transmitted from the pedal stroke detector 27. The target braking force is determined according to the will, and the pressure of the booster 22 is adjusted and controlled to reach the target braking force. Here, the target braking force is a hydraulic braking force, which is generated by the pressure of the master cylinder 23, and the pressure of the master cylinder 23 is generated by the brake fluid supplied from the booster 22.

When the brake fluid of the booster 22 is supplied to the master cylinder 23, the controller 50 controls the driving of the hydraulic controller 40 to increase or decrease the brake fluid and then supply the brake fluid to the wheel cylinder 26. Here, the brake fluid of the booster 22 supplied to the master cylinder 23 is adjusted by the hydraulic power unit 30 for optimum braking performance.

In addition, the controller 50 receives the high pressure accumulator pressure data and the booster pressure data from the high pressure accumulator pressure detector 35 and the booster pressure detector 38 to monitor the pressure state of the high pressure accumulator and the pressure state of the booster 22.

More specifically, the control unit 50 which performs the control for improving the optimum braking performance controls the driving of the cut valve 32 during braking so that the cut valve 32 is closed and the driving of the application valve 36 is performed. By controlling the opening of the applicator valve 36, the high pressure brake fluid stored in the high pressure accumulator 34 is supplied to the booster 22 through the applicator valve 36.

The controller 50 controls the driving of the cut valve 31 to close the cut valve 31 when the pressurization of the driver's pedal 21 is released, and controls the driving of the release valve 37 to release the valve 37. ) Is opened so that the brake fluid of the booster 22 is supplied to the reservoir 24 through the release valve 37. At this time, the brake fluid supplied to the master cylinder 25 is reduced.

The controller 50 controls the driving of the cut valve 32 while driving to open the cut valve 32, and controls the driving of the application valve 36 and the release valve 37 to control the application of the application valve 36. ) And the release valve 37 are closed, and the brake fluid of the reservoir 24 is pumped and supplied to the high pressure accumulator 34 by controlling the driving of the pump 33 so that the brake fluid is filled in the high pressure accumulator 34. do.

This will be described with reference to FIG. 4.

As shown in FIG. 4, when the brake pedal 21 is applied by the driver, it can be seen that the stroke travel data of the brake pedal 21 rises. It can be seen that the corresponding target pressure rises, and the application valve 36 is opened to improve braking performance, and the brake fluid of the high pressure accumulator 34 is supplied to the booster 22, thereby increasing the high pressure accumulator 34. It can be seen that the HPA pressure decreases, and that the brake fluid for following the target pressure is supplied to the wheel cylinder 26 to increase the M / C pressure of the master cylinder 23. Can be. At this time, the master cylinder 23 supplies the brake fluid supplied from the high pressure accumulator 34 to the wheel cylinder 26.

When the brake pedal 21 is pressed by the driver, the stroke travel data of the brake pedal 21 is maintained, and the target corresponding to the pressurization of the brake pedal 21 is maintained. It can be seen that the pressure (Target Pressure) is maintained, the go-ply valve 36 is opened so that the brake fluid of the high-pressure accumulator 34 is supplied to the booster 22 so that the pressure (HPA Pressure) of the high-pressure accumulator 34 is reduced. It can be seen that the pressure is maintained, and the pressure (M / C Pressure) of the master cylinder 23 that supplies the brake fluid for following the target pressure to the wheel cylinder 26 is maintained. At this time, the master cylinder 23 supplies the brake fluid supplied from the high pressure accumulator 34 to the wheel cylinder 26.

In addition, when the driver releases the pressurized state of the brake pedal 21, it can be seen that the stroke travel data of the brake pedal 21 is lowered, which corresponds to the release of the pressure of the brake pedal 21. It can be seen that the target pressure falls, and the brake fluid of the high pressure accumulator 34 is cut off to the booster 22 according to the closing of the application valve 36 and the opening of the release valve 37. It can be seen that the pressure (HPA Pressure) of the high pressure accumulator 34 rises, and the pressure (M / C Pressure) of the master cylinder 23 that supplies the brake fluid for following the target pressure to the wheel cylinder 26 is You can see the descent. At this time, the master cylinder 23 supplies the brake fluid supplied from the booster 22 to the wheel cylinder 26.

When the regenerative braking is performed, the controller 50 determines the target braking force according to the driver's intention based on the signal transmitted from the pedal stroke detection unit 27, controls the operation of the regenerative braking unit 60, and then controls the braking motor ( The regenerative braking force generated by 65) is calculated, and the hydraulic braking force required for the wheel braking is calculated by comparing the target braking force with the regenerative braking force of the braking motor 65. The hydraulic braking force is generated by the pressure due to the brake fluid supplied from the booster 22 to the master cylinder 23.

That is, the controller 50 controls the hydraulic power unit 30 to control the pressure of the booster 22 so that the pressure of the master cylinder 23 is adjusted, and a plurality of solenoid valves of the hydraulic control unit 40 (not shown). ), The brake fluid of the master cylinder 23 is supplied to the wheel cylinder 27.

As a result, hydraulic braking force is generated on the wheel cylinders 27 of the wheels 10 so that the vehicle is braked.

The control unit 50 calculates a target pressure of the booster 22 based on whether the hydraulic braking force is changed and the friction force of the seal S when the pressure of the booster 22 is controlled. Here, the hydraulic braking force is a braking force generated by the pressure generated in the master cylinder.

More specifically, the controller 50 determines whether the target pressure of the master cylinder 21 increases or decreases according to the pressurized state of the brake pedal 21, and if the target pressure of the master cylinder 23 increases, the master cylinder 23 The target pressure of the booster 22 is calculated by summing the frictional force of the seal S to the target pressure of), and if the target pressure of the master cylinder 23 decreases, the target pressure of the seal S The target pressure of the booster 22 is calculated by subtracting the frictional force.

The controller 250 controls the driving of the hydraulic power unit 30 so that the target pressure is formed in the booster 22, so that the brake fluid of the booster 22 is supplied to the master cylinder 23, thereby mastering the master cylinder 23. The target pressure of the cylinder 23 is generated.

Here, the frictional force of the seal S is determined in accordance with the mechanical characteristic value of the brake actuation portion 10 and is set in advance.

When the hydraulic braking force is changed from increasing to decreasing or decreasing to increasing, the control unit 50 fades out and fades in to prevent the target pressure of the booster 22 from changing discontinuously. Sets the interval in which in) is performed.

The regenerative braking unit 60 drives the vehicle according to the control signal of the controller 50 and brakes the vehicle according to the control signals of the braking motor 65 and the controller 50 which generate counter electromotive force according to the law of Fleming. It has a battery (not shown) which supplies power to the braking motor 65.

That is, the regenerative braking unit 60 performs regenerative braking by generating a rotational resistance while simultaneously performing energy regeneration with the rotational force of the braking motor 65 corresponding to the control signal of the controller 50. Here, the regenerative braking is to absorb the inertial force of the vehicle to go straight to the braking motor 65 when braking the vehicle, the braking motor 65 is generated by the back electromotive force in the characteristics and the energy generated at this time is stored in the battery.

5 is a control method of a brake system of a vehicle according to an exemplary embodiment of the present invention, which will be described with reference to FIGS. 1 and 3.

The cut valve 32 is opened while the vehicle driving is closed, and the application valve 36 and the release valve 37 are closed. Then, the pump 33 is periodically driven to pump the brake fluid of the reservoir 24 to fill the high pressure accumulator 34.

When the brake pedal 21 is pressed to decelerate or stop the vehicle, regenerative braking is performed by controlling the motor 65. At this time, the target braking force desired by the driver is determined 101 based on the pedal stroke detected by the pedal stroke detection unit 27, and the calculated target braking force is distributed to the wheel cylinders 26 on each wheel 10 side, respectively.

Next, the regenerative braking force may be calculated based on at least one of the rotational speed of the motor 65, the state of charge of the battery (not shown), and the vehicle state, and may be adjusted to the target braking force based on the calculated regenerative braking force. The hydraulic braking force present is calculated (103).

Here, the hydraulic braking force is a braking force generated by the pressure generated in the master cylinder.

Next, it is determined whether the target pressure of the master cylinder 21 increases or decreases according to the pressurized state of the brake pedal 21.

At this time, when the target pressure of the master cylinder 23 increases 104, the frictional force of the seal S is added to the target pressure of the master cylinder 23 to calculate the target pressure of the booster 22.

Next, the driving of the hydraulic power unit 30 is controlled so that a target pressure is formed in the booster 22, whereby the brake fluid of the booster 22 is supplied to the master cylinder 23.

As a result, the target pressure of the master cylinder 23 is generated in the master cylinder 23, and braking is performed 106 by supplying the brake fluid of the master cylinder 23 to the wheel cylinder 26.

In this way, in order to improve the optimum braking performance when braking the vehicle, by controlling the driving of the hydraulic power unit 30 so that the appropriate hydraulic pressure is formed in the master cylinder 23.

On the other hand, when the target pressure of the master cylinder 23 decreases 107, the target pressure of the booster 22 is calculated 108 by subtracting the frictional force of the seal S from the hydraulic braking force.

Next, the driving of the hydraulic power unit 30 is controlled so that a target pressure is formed in the booster 22, whereby the brake fluid of the booster 22 is supplied to the master cylinder 23.

As a result, the target pressure of the master cylinder 23 is generated in the master cylinder 23, and braking is performed 106 by supplying the brake fluid of the master cylinder 23 to the wheel cylinder 26.

Here, the frictional force of the seal S is determined in accordance with the mechanical characteristic value of the brake actuation portion 10 and is set in advance.

In addition, when the hydraulic braking force is changed from increasing to decreasing or decreasing to increasing, fade-out and fade-in are performed to prevent the target pressure of the booster 22 from changing discontinuously. Set the interval.

In more detail, the braking operation is closed, and the cut valve 32 and the applicator valve 36 are opened during the hydraulic braking.

Then, the high pressure brake fluid stored in the high pressure accumulator 34 is supplied to the booster 22 through the application valve 36, and the brake fluid supplied to the booster 22 is supplied to the master cylinder 23. The brake fluid of the cylinder 23 is supplied to the wheel cylinder 26 after being adjusted by the hydraulic control unit 40 to generate a braking force of the vehicle.

When the driver's pedal 21 is released, the release valve 37 is opened while the cut valve 31 is kept closed, and the brake fluid of the booster 22 is transferred through the release valve 37 to the reservoir 24. To supply. At this time, the brake fluid supplied to the master cylinder 23 is reduced, and at this time, the reduced brake fluid is supplied to the wheel cylinder 26.

This allows the driver to provide the desired braking force. It can also improve braking performance and reduce safety accidents.

10: wheel 21: brake pedal
22: booster 23: master cylinder
24: reservoir 25: pedal simulator
26: wheel cylinder 27: pedal stroke detection unit
30: hydraulic power unit 40: hydraulic control unit
50: control unit 60: regenerative braking unit

Claims (9)

A brake pedal for instructing braking of the vehicle;
Booster for boosting the pedal effort of the brake pedal;
A master cylinder generating hydraulic pressure in response to the boosting force of the booster;
A piston having a seal that maintains airtightness with the master cylinder and moving in response to pressurization of the brake pedal;
A pedal stroke detection unit detecting a pedal stroke of the brake pedal;
Hydraulic power unit for adjusting the pressure of the booster;
Back to determine if the target pressure in the master cylinder changes on the basis of the pedal stroke, when the target pressure of the master cylinder increased by adding a friction force of the seal to the target pressure of the master cylinder, calculating a target pressure of the booster, or And a control unit for controlling the hydraulic power unit to generate a target pressure of the booster by subtracting a frictional force of the seal from the target pressure of the master cylinder when the target pressure of the master cylinder decreases. Hydraulic power booster comprising a. delete delete The apparatus of claim 1,
And a target braking force based on the pedal stroke, and calculating a target pressure of the master cylinder corresponding to the target braking force. The apparatus of claim 1,
A target braking force is calculated based on the pedal stroke, a regenerative braking force generated by the braking motor is calculated, a hydraulic braking force is calculated by subtracting the regenerative braking force from the target braking force, and a target of the master cylinder corresponding to the hydraulic braking force is obtained. Hydraulic power system to calculate the pressure. A control method of a hydraulic power booster provided with a brake pedal for instructing braking of the vehicle, a booster for boosting the pedal effort of the brake pedal, a master cylinder for generating hydraulic pressure in response to the booster force of the booster, and a hydraulic power unit for adjusting the pressure of the booster. To
Detecting a pedal stroke of the brake pedal corresponding to the pressurized state of the brake pedal,
It is determined whether the target pressure of the master cylinder changes based on the pedal stroke,
If the target pressure of the master cylinder increases, the frictional force of the seal is added to the target pressure of the master cylinder to calculate the target pressure of the booster, and if the target pressure of the master cylinder decreases the seal to the target pressure of the master cylinder. Calculate the target pressure of the booster by subtracting the frictional force of
And a control method of the hydraulic power booster for controlling driving of the hydraulic power unit so that the calculated target pressure of the booster is generated. delete The method according to claim 6,
Generating a target pressure to the booster to supply brake fluid of the booster to the master,
The target pressure is formed in the master cylinder to supply brake fluid of the master cylinder to the wheel cylinder,
And generating a target braking force on the wheel cylinder. The method according to claim 6,
If the target pressure of the master cylinder is periodically changed, the control method of the hydraulic power booster further comprises setting a section in which fade out and fade in is performed.

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