WO2021201565A1

WO2021201565A1 - Vehicle brake control device and method for controlling same

Info

Publication number: WO2021201565A1
Application number: PCT/KR2021/003926
Authority: WO
Inventors: 전남주
Original assignee: 주식회사 만도
Priority date: 2020-03-30
Filing date: 2021-03-30
Publication date: 2021-10-07
Also published as: KR20220163406A

Abstract

A vehicle brake control device comprises: a low-pressure accumulator for temporarily storing brake fluid discharged from a wheel cylinder; a hydraulic pump for pumping the brake fluid stored in the low-pressure accumulator; a motor for driving the hydraulic pump; and a controller for controlling the motor, wherein the controller detects the counter-electromotive force of the motor when the motor is turned off during ABS control, and on the basis of the detected counter-electromotive force, estimates the pedal effort applied by a driver to the brake pedal.

Description

Vehicle brake control apparatus and method for controlling the same

The present invention relates to a vehicle braking control apparatus for determining a brake pedal pressure by a driver and a control method thereof.

In general, when controlling an anti-lock brake system (ABS) to prevent slippage due to wheel locking, it is important to select an opening degree of an inlet valve of the ABS in order to generate an optimal ABS braking cycle. .

The opening amount of the inlet valve is determined by the PWM (Pulse Width Modulation) duty of the inlet valve.

It is important to select the PWM duty to create an appropriate amount of pressure rise for optimal ABS control. Even if the PWM duty is constant, the amount of pressure increase varies according to the braking force applied to the brake pedal by the driver, so when determining the PWM duty, the braking force by the driver must be considered.

However, recently, from the viewpoint of reducing the cost, development of a low-cost vehicle brake control device in which a pressure sensor for detecting the pressure in the master cylinder is omitted is in progress.

In such a low-cost vehicle brake control device, it is difficult to select an optimal pressure increase amount because the level of the brake pedal pressure by the driver cannot be known.

One aspect provides a braking control apparatus for a vehicle capable of estimating a braking force of a brake pedal by a driver without using a pressure sensor for detecting a pressure in a master cylinder, and a method for controlling the same.

According to one aspect, a low pressure accumulator for temporarily storing the brake fluid discharged from the wheel cylinder; a hydraulic pump for pumping the brake fluid stored in the low pressure accumulator; a motor for driving the hydraulic pump; and a control unit for controlling the motor, wherein the control unit detects a counter electromotive force of the motor when the motor is turned off during ABS control, and estimates a stepping force of a brake pedal by a driver based on the detected counter electromotive force. A brake control device may be provided.

The control unit turns on/off the motor according to a preset pattern, detects the back electromotive force of the motor in the off section of the motor, calculates a back electromotive force reduction rate according to the detected back electromotive force, and based on the calculated back electromotive force reduction rate A pedal force of the brake pedal by the driver may be estimated.

and an inlet valve provided on the inlet side of the wheel cylinder, and the controller may compensate for a PWM (Pulse Width Modulation) duty output to the inlet valve based on the estimated brake pedal effort.

According to another aspect, a low-pressure accumulator for temporarily storing the brake fluid discharged from the wheel cylinder; a hydraulic pump for pumping the brake fluid stored in the low pressure accumulator; a motor for driving the hydraulic pump; an inlet valve provided on the inlet side of the wheel cylinder; and a control unit controlling the motor and the inlet valve, wherein the control unit detects a counter electromotive force of the motor in an OFF section of the motor during ABS control, and based on the detected back electromotive force, the inlet in an ON section of the motor A vehicle brake control device may be provided that compensates for the PWM duty of the valve.

The control unit turns on/off the motor according to a preset pattern, calculates a counter electromotive force reduction rate according to the detected back electromotive force, estimates a brake pedal effort by the driver based on the calculated back electromotive force decrease rate, and the estimated The PWM duty of the inlet valve may be compensated according to the brake pedal effort.

According to another aspect, there is provided a method for controlling a brake control apparatus for a vehicle including a motor for driving a hydraulic pump for pumping brake fluid stored in a low-pressure accumulator for temporarily storing brake fluid discharged from a wheel cylinder, wherein the ABS is controlled. A method for controlling a brake control apparatus for a vehicle may be provided, wherein a counter electromotive force of the motor is detected when the motor is turned off, and a stepping force of a brake pedal by a driver is estimated based on the detected counter electromotive force.

In detecting the motor back EMF, the motor may be turned on/off according to a preset pattern, and the back EMF of the motor may be detected in an OFF section of the motor.

In estimating the brake pedal effort, a counter electromotive force reduction rate may be calculated according to the detected back electromotive force, and a pedal effort of the brake pedal by the driver may be estimated based on the calculated counter electromotive force decrease rate.

The PWM duty output to the inlet valve provided at the inlet side of the wheel cylinder may be compensated based on the estimated brake pedal effort during the on-period of the motor.

The present invention can estimate the braking force of the brake pedal by the driver without using a pressure sensor for detecting the pressure in the master cylinder.

According to the present invention, it is possible to estimate the braking effort by the driver, so that the optimal pressure increase amount can be selected during ABS control.

1 shows a configuration of a vehicle equipped with a vehicle brake control apparatus according to an embodiment.

2 shows a hydraulic circuit of a brake control apparatus for a vehicle according to an embodiment.

3 shows a control block of a brake control apparatus for a vehicle according to an embodiment.

4 is a diagram illustrating a case in which a back electromotive force is detected when a motor is turned off in the apparatus for controlling a brake of a vehicle according to an embodiment.

5 is a graph illustrating a correlation between a motor counter electromotive force reduction rate and a brake pedal effort force in the brake control apparatus for a vehicle according to the embodiment.

6 is a diagram illustrating the control of the PWM duty of the inlet valve according to the brake pedal effort estimated by the motor counter electromotive force in the braking control apparatus for a vehicle according to the embodiment.

7 is a diagram illustrating compensating for PWM duty of an inlet valve according to a brake pedal effort in the brake control apparatus for a vehicle according to the embodiment.

8 is a flowchart illustrating a control method of a vehicle braking control apparatus according to an embodiment.

Like reference numerals refer to like elements throughout. This specification does not describe all elements of the embodiments, and general content in the technical field to which the disclosed invention pertains or content overlapping between the embodiments is omitted. The term 'part, module, member, block' used in the specification may be implemented in software or hardware, and according to embodiments, a plurality of 'part, module, member, block' may be implemented as one component, It is also possible for one 'part, module, member, block' to include a plurality of components.

Throughout the specification, when a part is “connected” with another part, it includes not only direct connection but also indirect connection, and indirect connection includes connection through a wireless communication network. do.

In addition, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

Throughout the specification, when a member is said to be “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member exists between two members.

Terms such as 1st, 2nd, etc. are used to distinguish one component from another component, and the component is not limited by the above-mentioned terms. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In each step, the identification code is used for convenience of description, and the identification code does not describe the order of each step, and each step may be performed differently from the specified order unless the specific order is clearly stated in the context. have.

1 , the vehicle includes a hydraulic pressure generating device 32 that generates brake hydraulic pressure based on the amount of operation the driver presses on a brake pedal 31, and is connected to the hydraulic pressure generating device 32 and each wheel FL, FR, It may include a hydraulic unit (HU) 33 for supplying braking force to RL and RR, and a control unit 34 for controlling the hydraulic unit 33 .

The control unit 34 may be referred to as an Electronic Control Unit (ECU).

The controller 34 may include a processor 34a and a memory 34b.

The memory 34b may store a program for processing or controlling the processor 34a and various data for operating the vehicle brake control device.

The memory 34b includes not only volatile memories such as S-RAM and D-RAM, but also flash memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), etc. of non-volatile memory.

The processor 34a may control the overall operation of the vehicle brake control device.

The control unit 34 may receive each wheel speed information detected by each wheel speed sensor 36 .

The controller 34 may adjust the brake hydraulic pressure supplied to or discharged from the brake caliper 41 provided on each wheel FL, RR, RL, and FR through the hydraulic unit HU 33 .

The hydraulic unit (HU) 33 may supply brake hydraulic pressure to the brake caliper 41 according to a control signal from the controller 34 .

The hydraulic unit (HU) 33 may discharge the brake hydraulic pressure of the brake caliper 41 according to a control signal of the controller 34 .

Referring to FIG. 2 , the hydraulic pressure generating device 32 includes a booster VB for boosting the pedal effort of the brake pedal 31 and brake hydraulic pressure according to the pedal effort of the brake pedal 31 boosted by the booster VB. It may include a master cylinder (MC) for generating

The brake hydraulic pressure generated in the master cylinder MC may be supplied to the hydraulic unit 33 . The master cylinder MC may supply brake hydraulic pressure corresponding to a brake pedal operation amount by the driver to the hydraulic unit 33 .

The hydraulic unit 33 includes low-pressure accumulators LPA1 and LPA2 for temporarily storing brake fluid discharged from the wheel cylinders Wfr, Wrl, Wfl, and Wrr in each brake caliper 41, and the low-pressure accumulators LPA1 and LPA2. ), a hydraulic pump (HP1, HP2) that pumps the brake fluid stored in ) and supplies it to each wheel cylinder (Wfr, Wrl, Wfl, Wrr), a motor (M) connected to the hydraulic pump (HP1, HP2), and a master Solenoid valves (IN1-IN4) supplying brake fluid supplied from the cylinder (MC) or hydraulic pumps (HP1, HP2) to each wheel cylinder (Wfr, Wrl, Wfl, Wrr), and each wheel cylinder (Wfr, Wrl, Solenoid valves OUT1-OUT4 for discharging brake fluid in Wfl and Wrr to the low-pressure accumulators LPA1 and LPA2 may be included.

The hydraulic unit 33 may include two hydraulic circuits HC1 and HC2 connected to the master cylinder MC.

The first hydraulic circuit HC1 and the second hydraulic circuit HC2 connect the brake hydraulic pressure generated by the master cylinder MC to each wheel cylinder Wfr, Wrl, Wfl, and Wrr. Each of the hydraulic circuits HC1 and HC2 may form a closed circuit in which the brake fluid circulates.

The first hydraulic circuit HC1 and the second hydraulic circuit HC2 may be controlled by connecting two wheel cylinders Wfr, Wrl, Wfl, and Wrr, respectively. The second hydraulic circuit HC2 is configured independently of the first hydraulic circuit HC1, but has the same arrangement structure.

A wheel cylinder Wfr providing a braking force to the right front wheel FR and a wheel cylinder Wrl providing a braking force to the left rear wheel RL are connected to the first hydraulic circuit HC1.

A wheel cylinder Wfl providing a braking force to the left front wheel FL and a wheel cylinder Wrr providing a braking force to the right rear wheel RR are connected to the second hydraulic circuit HC2 .

The normally open inlet valves IN1 and IN2 are provided on the inlet side of the wheel cylinders Wfr and Wrl in the first hydraulic circuit HC1, and the inlet side of the wheel cylinders Wfl and Wrr in the second hydraulic circuit HC2. The normally open inlet valves (IN3, IN4) are connected to the The normally open inlet valves IN1, IN2, IN3, and IN4 may be driven when the brake fluid pressure in each wheel cylinder Wfr, Wrl, Wfl, and Wrr is increased.

In addition, normally closed outlet valves OUT1 and OUT2 are connected to the outlet side of the wheel cylinders Wfr and Wrl to the first hydraulic circuit HC1, and the normally closed outlet valves are connected to the outlet side of the wheel cylinders Wfl and Wrr. The valves OUT3 and OUT4 are connected. The normally open outlet valves OUT1, OUT2, OUT3, and OUT4 may be driven when the brake fluid pressure in each wheel cylinder Wfr, Wrl, Wfl, and Wrr is reduced.

A low-pressure accumulator (LPA1) for temporarily storing the brake fluid discharged from the wheel cylinders (Wfr, Wrl) of each wheel (FR, RL) is provided at the outlet side of the normally closed outlet valves (OUT1, OUT2), and the normally closed outlet A low-pressure accumulator LPA2 for temporarily storing brake fluid discharged from the wheel cylinders Wfl and Wrr of each wheel FL and RR may be provided at the outlet side of the valves OUT3 and OUT4 .

The hydraulic pumps (HP1, HP2) that pump the brake fluid stored in the low pressure accumulators (LPA1, LPA2) and forcibly reflux to the side of each wheel cylinder (Wfr, Wrl, Wfl, Wrr), and the hydraulic pumps (HP1, HP2) connected to the A motor M is provided.

Here, a normally open (NO: Normal Open) valve opens the valve flow path before being energized and closes the valve flow path when energized, and a normally closed (NC: Normal Close) valve closes the valve flow path before energization and closes the valve flow path when energized. can be opened

The vehicle brake control device having the above configuration controls the operation of the inlet valves IN1-IN4 and the outlet valve OUT1-OUT4 during ABS control to increase the brake fluid pressure of each wheel cylinder (Wfr, Wrl, Wfl, Wrr). , by holding or depressurizing, it is possible to generate a braking force for each wheel (FL, FR, RL, RR).

When the brake pressure of the wheel cylinders (Wfr, Wrl, Wfl, Wrr) is increased, the inlet valves (IN1-IN4) are opened, the outlet valves (OUT1-OUT4) are closed, and the brake fluid with the increased brake pressure is applied to the wheel. The hydraulic pumps HP1 and HP2 are operated by driving the motor M to be supplied to the cylinders Wfr, Wrl, Wfl, and Wrr. Due to this, the brake pressure of the wheel cylinders Wfr, Wrl, Wfl, and Wrr may be increased. As the brake hydraulic pressure in the wheel cylinders Wfr, Wrl, Wfl, and Wrr increases, the brake caliper 41 may operate.

When the brake pressure of the wheel cylinders (Wfr, Wrl, Wfl, Wrr) is maintained, the inlet valves (IN1-IN4) and the outlet valves (OUT1-OUT4) are closed respectively to brake the wheel cylinders (Wfr, Wrl, Wfl, Wrr). The pressure can be maintained.

When the brake pressure of the wheel cylinders (Wfr, Wrl, Wfl, Wrr) is reduced, the motor (M) is stopped to stop the hydraulic pumps (HP1, HP2), and the inlet valves (IN1-IN4) are closed, Discharge the brake fluid from the wheel cylinders (Wfr, Wrl, Wfl, Wrr) to the low pressure accumulators (LPA1, LPA2) by opening the outlet valves (OUT1-OUT4). Due to this, the brake pressure of the wheel cylinders Wfr, Wrl, Wfl, and Wrr can be reduced.

Referring to FIG. 3 , a wheel speed sensor 36 and a counter electromotive force detection unit 37 are electrically connected to the input side of the control unit 34 .

The control unit 34 is electrically connected to the inlet valves IN1-IN4, the outlet valves OUT1-OUT4 and the motor M on the output side.

The controller 34 may control the driving of the inlet valves IN1-IN4, the outlet valves OUT1-OUT4, and the motor M during ABS control based on the information detected by the wheel speed sensor 36 .

During braking control (ABS control), if the braking torque is simply increased or decreased for each wheel, the braking torque is greatly changed, and noise and vibration as well as ABS performance itself may become severe. Accordingly, LFC control, commonly referred to as linear flow control (hereinafter referred to as LFC), which smoothly increases or decreases the braking torque or maintains it constant in some cases is applied. This LFC control controls the duty ratio of the current supplied to the solenoid valves instead of simply completely opening or completely closing the solenoid valves that control the braking torque of the wheels by regulating the brake fluid supplied to the wheel cylinders of each wheel by a switching method. It smoothly increases or decreases the braking torque of the wheel by controlling the opening degree of the valve by using the pulse width modulation (PWM) method, which is adjusted for each predetermined cycle.

As described above, it is important to select the opening amount of the inlet valves IN1-IN4 in order to generate an optimal ABS braking cycle during ABS control. The opening degree of the corresponding inlet valve is determined by the PWM duty of the inlet valve. When the PWM duty is small, the valve opening amount is increased to increase the pressure rise, deep slip occurs, the brake pedal 31 vibrates excessively, and the number of ABS braking cycles is relatively increased. On the other hand, if the PWM duty is large, the valve opening amount is reduced, resulting in a delay in pressure rise, resulting in braking loss and reducing the number of ABS braking cycles. As such, it is important to select the PWM duty to create an appropriate amount of pressure rise for optimal ABS control. At this time, even if the PWM duty is constant, the amount of pressure increase varies depending on the brake pedal pressure by the driver, so when determining the PWM duty, the driver's brake pedal pressure must be considered. However, in the case of a low-cost braking system, since the level of the driver's pedal effort cannot be known, it is difficult to select an optimal pressure increase amount.

Referring back to FIG. 3 , the controller 34 estimates the pedal effort of the brake pedal 31 by the driver based on the back electromotive force of the motor M detected through the back electromotive force detector 37 during braking control (ABS control). can do. The control unit 34 detects the back electromotive force of the motor M in the section in which the motor M is turned off during ABS control, calculates a reduction rate of the back electromotive force according to the detected back electromotive force of the motor M, and calculates the reduction rate of the calculated back electromotive force. Based on this, it is possible to estimate the braking force of the brake pedal by the driver.

The back electromotive force detection unit 37 may detect a back electromotive force generated in the motor M.

For example, when the motor M rotates, a counter electromotive force due to an induced electromotive force is generated in a coil to which a phase voltage is not applied among coils provided in the rotor. Accordingly, the counter electromotive force detection unit 37 may detect the counter electromotive force generated in each coil of the motor M as described above.

The controller 34 may turn on or off the motor M according to a preset on/off pattern to control the speed of the motor M during ABS control (see FIG. 4 ).

During ABS control, on and off of the motor M may be determined by a target voltage of the motor M and a motor back-emf. The motor M is turned on for a preset time, and after the motor is turned off, when the target voltage and the counter electromotive force meet, the motor M can be turned on again. In this case, the motor on time may be determined according to the motor off time. If the motor off time is long, the motor on time can be set short, and when the motor off time is short, the motor on time can be set long.

The controller 34 may detect the counter electromotive force of the motor M in order to estimate the pedal force of the brake pedal 31 in the off section of the motor M (refer to FIG. 4 ).

The controller 34 controls the motor speed by using the counter electromotive force of the motor M when controlling the motor M during ABS control. Since the back electromotive force of the motor M generated when the motor M is turned off is proportional to the motor speed, when the driver presses the brake pedal 31 strongly, the pressure of the master cylinder MC is also high, and the motor speed is rapidly reduced. As such, there is a correlation between the back electromotive force reduction rate and the master cylinder pressure.

5 is a graph illustrating a correlation between a motor counter electromotive force reduction rate and a master cylinder pressure in the brake control apparatus for a vehicle according to the embodiment.

Referring to FIG. 5 , it can be seen that the reduction rate of the counter electromotive force when the motor is turned off is changed according to the master cylinder pressure according to the brake pedal effort by the driver.

It can be seen that the back electromotive force reduction rate increases as the master cylinder pressure increases due to the high brake pedal effort.

When the motor is turned off, the counter electromotive force reduction rate section can be selected in consideration of the inlet valves IN1-IN4 and the outlet valves OUT1-OUT4.

As described above, since the tendency of the master cylinder pressure and the motor back EMF reduction rate can be confirmed, the brake pedal effort can be reliably estimated according to the motor back EMF reduction rate. In the memory 34b of the controller 34 , a brake pedal effort (or master cylinder pressure) corresponding to a reduction rate of the motor counter electromotive force may be previously stored in the form of a map. The controller 34 may determine the brake pedal effort by using this map.

In this way, since the brake pedal effort level by the driver during ABS braking can be distinguished, the brake pedal effort force is estimated according to the motor counter electromotive force when the motor is off, and then the PWM duty of the inlet valves (IN1-IN4) is changed according to the brake pedal effort force. Therefore, it is possible to perform optimal ABS control (see FIG. 6 ).

Meanwhile, in the case of a braking control device (eg, a vehicle attitude control device) having a pressure sensor for detecting the pressure in the master cylinder, the PWM duty of the inlet valve may be compensated according to a brake pedal pressure by the driver. However, this low-cost brake control device without a pressure sensor (for example, an ABS device) has no concept of compensating for the brake pedal effort.

Referring to FIG. 7 , the brake pedal effort level is divided into low pedal effort, medium pedal effort, or high pedal effort based on a preset pedal effort range by estimating the brake pedal effort force using the motor back electromotive force in the ABS specification, and each pedal effort situation The PWM duty of the inlet valve can be compensated according to

For example, when the brake pedal effort is low, the PWM duty output to the inlet valve may be reduced by subtracting a preset PWM duty (compensation duty) from the initial PWM duty of the inlet valve. In addition, when the brake pedal effort is a medium pedal effort, the PWM duty output to the inlet valve may be maintained as it is. Also, when the brake pedal effort is high, the PWM duty output to the inlet valve may be increased by adding a preset PWM duty (compensation duty) to the initial PWM duty of the inlet valve.

Meanwhile, the controller 34 may compensate the PWM duty of the inlet valve IN based on the back electromotive force of the motor M during braking control. The controller 34 may compensate for the PWM duty of the inlet valve IN based on a reduction rate of the back electromotive force of the motor M during braking control.

The controller 34 may compensate for the PWM duty by reducing the initial PWM duty of the inlet valve when the counter electromotive force reduction rate of the motor M is within a preset first reduction rate range.

The controller 34 may maintain the PWM duty of the inlet valve as the initial PWM duty when the counter electromotive force reduction rate of the motor M is in a preset second reduction ratio range higher than the preset first reduction ratio range.

The controller 34 may compensate the PWM duty of the inlet valve with a PWM duty higher than the initial PWM duty when the counter electromotive force reduction rate of the motor M is in a preset third reduction ratio range higher than the preset second reduction ratio range.

Referring to FIG. 8 , the controller 34 may drive the motor M according to a preset on/off pattern ( 100 ). In this case, the controller 34 may drive the motor M according to a preset on/off pattern during ABS control ( 100 ). That is, the motor M may be operated to repeat on/off with a predetermined cycle without continuously operating the motor M. FIG. The control unit 34 controls the motor M and controls each inlet valve IN and each outlet valve OUT to increase, decrease, and maintain the brake pressure of the brake caliper 41 to prevent wheel slippage. can do.

The controller 34 may detect a counter electromotive force of the motor M when the motor M is turned off during the motor driving (102) (104).

The control unit 34 may calculate a reduction rate of the back electromotive force according to the detected back electromotive force of the motor M ( 106 ).

The control unit 34 may estimate the pedal effort of the brake pedal 31 by the driver based on the calculated reduction rate of the back electromotive force ( 108 ).

Thereafter, the optimal ABS control may be performed by compensating or determining the PWM duty of the inlet valve IN using the estimated brake pedal effort.

Claims

a low-pressure accumulator for temporarily storing brake fluid discharged from the wheel cylinders;

a hydraulic pump for pumping the brake fluid stored in the low pressure accumulator;

a motor for driving the hydraulic pump; and

A control unit for controlling the motor,

The control unit detects a counter electromotive force of the motor when the motor is turned off during ABS control, and estimates a brake pedal effort by a driver based on the detected counter electromotive force.
According to claim 1,

The control unit turns on/off the motor according to a preset pattern, detects the back electromotive force of the motor in the off section of the motor, calculates a back electromotive force reduction rate according to the detected back electromotive force, and based on the calculated back electromotive force reduction rate A vehicle braking control apparatus for estimating a braking force of a brake pedal by the driver.
According to claim 1,

Including an inlet valve provided on the inlet side of the wheel cylinder,

The control unit is configured to compensate a PWM (Pulse Width Modulation) duty output to the inlet valve based on the estimated brake pedal effort.
a low-pressure accumulator for temporarily storing brake fluid discharged from the wheel cylinders;

a hydraulic pump for pumping the brake fluid stored in the low pressure accumulator;

a motor for driving the hydraulic pump;

an inlet valve provided on the inlet side of the wheel cylinder; and

A control unit for controlling the motor and the inlet valve,

The control unit detects a counter electromotive force of the motor in an off section of the motor during ABS control, and compensates for a PWM duty of the inlet valve in an on section of the motor based on the detected back electromotive force.
5. The method of claim 4,

The control unit turns on/off the motor according to a preset pattern, calculates a counter electromotive force reduction rate according to the detected back electromotive force, estimates a brake pedal effort by the driver based on the calculated back electromotive force decrease rate, and the estimated A brake control device for a vehicle that compensates the PWM duty of the inlet valve according to a brake pedal effort.
A method of controlling a brake control apparatus for a vehicle, comprising a motor for driving a hydraulic pump for pumping brake fluid stored in a low-pressure accumulator for temporarily storing brake fluid discharged from wheel cylinders, the method comprising:

Detecting the back electromotive force of the motor when the motor is turned off during ABS control,

A control method of a vehicle braking control apparatus for estimating a brake pedal effort by a driver based on the detected back electromotive force.
7. The method of claim 6,

In detecting the motor back EMF, turning the motor on/off according to a preset pattern, and detecting the back EMF of the motor in an OFF section of the motor, the control method of a braking control apparatus of a vehicle.
8. The method of claim 7,

In the estimation of the brake pedal effort, a counter electromotive force reduction rate is calculated according to the detected back electromotive force, and the brake pedal pedal effort by the driver is estimated based on the calculated counter electromotive force decrease rate.
7. The method of claim 6,

A method of controlling a brake control apparatus of a vehicle for compensating for a PWM duty output to an inlet valve provided at an inlet side of the wheel cylinder based on the estimated brake pedal effort during an on section of the motor.