KR20190094801A - Braking force control device for vehicle and control method thereof - Google Patents

Abstract

Disclosed are a braking force control device for a vehicle and a control method thereof. According to an embodiment of the present invention, the braking force control device for a vehicle calculates a target braking force corresponding to a pedal effort of a brake pedal operated by a driver and controls the braking force of the vehicle based on the calculated target braking force. The braking force control device comprises: a pedal effort sensor detecting a pedal effort of a brake pedal; a vehicle speed sensor detecting a vehicle speed; a storage unit storing a reference braking distance; and an electronic control unit calculating a braking distance of a driving road surface based on the detected pedal effort of the brake pedal and the vehicle speed, and correcting a target braking force according to a result of comparing the calculated braking distance with the stored reference braking distance.

Description

BRAKING FORCE CONTROL DEVICE FOR VEHICLE AND CONTROL METHOD THEREOF}

The present invention relates to a vehicle braking force control device and a control method, and more particularly to a vehicle braking force control device and a control method for controlling the braking force of the vehicle in accordance with the driver's foot pedal.

In general, when the brake pedal is operated by the driver, the vehicle braking force control device calculates a target braking force according to the brake pedal stepping force, and controls the braking force of the vehicle by operating the motor based on the calculated target braking force.

Conventionally, if the brake pedal response is the same without considering the road condition, the braking distance is increased on the road where the frictional force is lower than the dry road such as rain because the braking force of the vehicle is controlled by calculating the same target braking force.

Republic of Korea Patent Publication No. 10-1469563 (2014.12.01.Registration)

An embodiment of the present invention is to provide a vehicle braking force control device and a control method that can ensure the same braking distance regardless of the road surface condition.

According to an aspect of the present invention, the braking force control apparatus of the vehicle for calculating a target braking force corresponding to the stepping force of the brake pedal operated by the driver, and controls the braking force of the vehicle based on the calculated target braking force, the brake A stepping sensor for detecting a stepping force of the pedal; A vehicle speed sensor detecting a vehicle speed; A storage unit storing a reference braking distance; And an electronic control unit for calculating a braking distance of the road surface based on the detected brake pedal response and the vehicle speed, and correcting the target braking force according to a result of comparing the calculated braking distance with the stored reference braking distance. A braking force control device for a vehicle may be provided.

The electronic control unit may increase the target braking force when the calculated braking distance is longer than the stored reference braking distance.

In addition, a rain sensor for detecting rain water, the electronic control unit may increase the target braking force when rain water is detected through the rain sensor.

The electronic control unit may increase the target braking force when the braking distance shortening function activated by the driver's command input through the input unit is activated.

The reference braking distance may be pre-stored in the storage unit to correspond to the vehicle speed and the brake pedal effort on the reference road surface.

According to another aspect of the present invention, the braking force control method of the vehicle for calculating a target braking force corresponding to the stepping force of the brake pedal operated by the driver, and controls the braking force of the vehicle based on the calculated target braking force, the brake Detects the pedal effort of the pedal, detects the speed of the vehicle, calculates a braking distance of the road surface based on the detected brake pedal effort and the vehicle speed, and calculates the braking distance and the reference braking distance stored in the storage unit. Compared to, and if the calculated braking distance is longer than the stored reference braking distance, a vehicle braking force control method for increasing the target braking force may be provided.

In addition, the target braking force increase may detect rainwater through a rain sensor and increase the target braking force when the rainwater is detected.

In addition, the target braking force increase may increase the target braking force when the braking distance shortening function activated by the driver's command input through the input unit is activated.

According to the exemplary embodiment of the present invention, the same braking distance may be secured regardless of the road surface state by increasing or decreasing the target braking force according to the brake pedal effort according to the road state.

1 is a hydraulic circuit diagram of a vehicle braking force control apparatus according to an embodiment of the present invention.
2 is a control block diagram of a vehicle braking force control apparatus according to an embodiment of the present invention.
3 is a control flowchart illustrating a braking force control method for a vehicle according to an exemplary embodiment of the present invention.
4 is a control flowchart of a braking force control method for a vehicle according to another exemplary embodiment of the present disclosure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. Parts not related to the description are omitted in the drawings in order to clearly describe the present invention, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 is a hydraulic circuit diagram of a vehicle braking force control apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a vehicle braking force control device includes a master cylinder MC for generating brake pressure by an operation of a vacuum booster VB by a pressure of a brake pedal BP, the master cylinder MC, and a hydraulic line. Is connected through may include a wheel cylinder (Wfr, Wrl, Wfl, Wrr) receiving the brake fluid from the master cylinder (MC).

The vehicle braking force control device pumps the brake fluid of the reservoir LRS and supplies the hydraulic pumps HP1 and HP2 to the wheel cylinders Wfr, Wrl, Wfl and Wrr, and the hydraulic pumps HP1 and HP2. Low pressure accumulators LPA1 and LPA2 for temporarily storing the brake fluid and solenoid valves for returning the brake fluid supplied from the master cylinder MC to the wheel cylinders Wfr, Wrl, Wfl and Wrr or to the reservoir LRS. (TC1, TC2, ESV1, ESV2, IN1-IN4, OUT1-OUT4).

The master cylinder (MC) has two chambers, and the hydraulic line between the first chamber of the master cylinder (MC) and the wheel cylinders (Wfr, Wrl) installed in the front wheel right wheel (FR) and the rear wheel left wheel (RL) respectively. Normally open traction control valve TC1 is provided. The normal open traction control valve TC1 controls the brake fluid transferred from the master cylinder MC to the wheel cylinders Wfr and Wrl of each wheel.

The normal open traction control valve TC2 is provided in the hydraulic line between the second chamber of the master cylinder MC and the wheel cylinders Wfl and Wrr respectively installed in the front wheel left wheel FL and the rear wheel right wheel RR. The normal open traction control valve TC2 controls the brake fluid transferred from the master cylinder MC to the wheel cylinders Wfl and Wrr of the respective wheels FL and RR.

In the hydraulic line between the normal open traction control valve (TC1) and the wheel cylinders (Wfr, Wrl) of each wheel (FR, RL), a normal open solenoid valve (IN1, IN2) is provided, and the normal open type traction control valve (TC2) Normally open solenoid valves IN3 and IN4 are provided in the hydraulic line between the wheel cylinders Wfl and Wrr of the wheels FL and RR.

Normally closed solenoid valves OUT1 and OUT2 are provided on the outlet side of the wheel cylinders Wfr and Wrl of each wheel FR and RL, and on the outlet side of the wheel cylinders Wfl and Wrr of each wheel FL and RR. Normally closed solenoid valves OUT3 and OUT4 are provided.

On the outlet side of the normal closed solenoid valves OUT1 and OUT2, a low pressure accumulator LPA1 for temporarily storing brake fluid discharged from the wheel cylinders Wfr and Wrl of each wheel FR and RL is provided, and the normal closed solenoid is provided. At the outlet side of the valves OUT3 and OUT4, a low pressure accumulator LPA2 for temporarily storing brake fluid discharged from the wheel cylinders Wfl and Wrr of the wheels FL and RR is provided.

Two hydraulic pumps (HP1, HP2) for pumping brake fluid stored in the low pressure accumulators (LPA1, LPA2) and forced reflux to the wheel cylinders (Wfr, Wrl, Wfl, Wrr) and two hydraulic pumps (HP1, HP2) One motor M is provided.

In the auxiliary hydraulic line between the suction side of the two hydraulic pumps HP1 and HP2 and the respective chambers of the master cylinder MC, normal closed electronic shuttle valves ESV1 and ESV2 are provided. Accordingly, when the normal closed electronic shuttle valves ESV1 and ESV2 are opened, the auxiliary hydraulic line between the master cylinder MC and the hydraulic pumps HP1 and HP2 is opened, and the normal closed electronic shuttle valves ESV1 and ESV2 are opened. ) Is closed, the auxiliary hydraulic line between the master cylinder (MC) and each hydraulic pump (HP1, HP2).

In this case, the NO (normal open) valve opens the valve flow path before energizing and closes the valve flow path when energized, and the normal close valve (NC) closes the valve flow path before energized and the valve flow path when energized. To open.

When the braking force control device for a vehicle increases the braking force, the vehicle is normally opened according to an instruction of the electronic control unit (ECU) 10 which performs a control mode such as an anti-lock brake system (ABS) mode or an electronic stability control (ESC) mode. Open the solenoid valves (IN1-IN4) and drive the hydraulic pumps (HP1, HP2) to transfer the brake fluid from the reservoir (LRS) or the low pressure accumulator (LPA1, LPA2) through the normal open solenoid valves (IN1-IN4). Wfr, Wrl, Wfl, Wrr) to increase the pressure of the wheel cylinders (Wfr, Wrl, Wfl, Wrr). At this time, the wheel cylinders (Wfr, Wrl, Wfl, Wrr) in the reservoir (LRS) through the hydraulic line connected between the reservoir (LRS) and the hydraulic pumps (HP1, HP2) without passing through the hydraulic line on the master cylinder (MC) side. It is possible to supply pressure directly to the furnace.

In addition, when the braking force is decreased, the hydraulic pumps HP1 and HP2 are stopped and the normal closed solenoid valves OUT1 to OUT4 are opened in response to the command of the electronic control unit 10, and the wheel cylinders Wfr, Wrl, Wfl, and Wrr are opened. The pressure in the wheel cylinders (Wfr, Wrl, Wfl, Wrr) is reduced by returning the brake fluid of the < RTI ID = 0.0 >) < / RTI > to the reservoir LRS through the normal closed solenoid valves OUT1-OUT4. In this case, the brake fluid discharged from the wheel cylinders Wfr, Wrl, Wfl, and Wrr may be temporarily stored in the low pressure accumulators LPA1 and LPA2.

Normally open traction control valve (TC1, TC2), normally closed electronic shuttle valve (ESV1, ESV2), normal open solenoid valve (IN1-IN4), normal closed solenoid valve (OUT1-OUT4), hydraulic pump (HP1) of FIG. The motor M for operating the HP2 is operated by the electronic control unit (ECU) 10 to increase, decrease or maintain the braking pressure of the corresponding wheel.

2 is a control block diagram of a vehicle braking force control apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the vehicle braking force control device includes an electronic control unit 10 that performs overall control.

The electronic control unit 10 is electrically connected to the step sensor 20, the vehicle speed sensor 30, the rain sensor 40 and the input unit 50 on the input side.

The stepping force sensor 20 detects a stepping force of the brake pedal BP operated by the driver. The stepping force sensor 20 transmits a signal indicating a stepping force of the brake pedal BP to the electronic control unit 10.

The vehicle speed sensor 30 detects the speed of the vehicle. The vehicle speed sensor 30 may include four wheel speed sensors for detecting the speed of each wheel, and may detect the vehicle speed by using an average value of each wheel speed detected by the four wheel speed sensors. The vehicle speed sensor 30 transmits a signal indicating the speed of the vehicle to the electronic control unit 10.

Rain sensor 40 detects rain water. Rain sensor 40 is provided on the top of the windshield of the vehicle to detect rain water. The rain sensor 40 emits infrared rays and detects the wavelength between the infrared rays hitting the glass window and returning to the sensor. If rainwater collects outside the window, diffuse reflection occurs and the sensor detects the presence of rainwater. Rain sensor 40 transmits a signal indicating the presence of rain water to the electronic control unit (10).

The input unit 50 receives a driver's command. The input unit 50 receives from the driver whether or not to activate a function for shortening a braking distance in rainy weather. The input unit 50 transmits a signal indicating whether to activate the braking distance shortening function in rainy weather to the electronic control unit 10. For example, the driver may input a command to the input unit 10 to activate or deactivate the rain sensor 40. The input unit 10 transmits a signal indicating activation or deactivation of the rain sensor 40 to the electronic control unit 10.

On the output side of the electronic control unit 10, normally closed electronic shuttle valves (ESV1, ESV2), normal open type traction control valves (TC1, TC2), normal open solenoid valves (IN1-IN4), normal closed solenoid valves (OUT1-OUT4) ), The motor M is electrically connected. The electronic control unit 10 includes a normal closed electronic shuttle valve (ESV1, ESV2), a normal open type traction control valve (TC1, TC2), a normal open solenoid valve (IN1-IN4), a normal closed solenoid valve (OUT1-OUT4), and Output a control signal to the motor (M).

The storage unit 60 is electrically connected to the input / output side of the electronic control unit 10. The storage unit 60 stores a reference braking distance, which is a braking distance of the reference road surface. The reference road surface may be a road surface having a high road friction coefficient such as a dry road surface. The storage unit 60 may store in advance a reference braking distance corresponding to the brake pedal effort on the reference road surface and the vehicle speed. This reference braking distance may be a function corresponding to brake pedal effort and vehicle speed. The reference braking distance can be stored in advance by experiment. In addition, the braking distance is calculated based on the deceleration rate of the vehicle speed relative to the brake pedal effort by receiving the brake pedal effort and vehicle speed for a preset number of times on the reference surface while the vehicle is driving, and the preset braking distance for each calculated braking distance. The average braking distance can be stored.

The electronic control unit 10 calculates a target braking force corresponding to the stepping force of the brake pedal BP operated by the driver in controlling the braking force, and controls the braking force of the vehicle based on the calculated target braking force. For example, the electronic control unit 10 calculates the target deceleration based on the stepping force of the brake pedal BP, calculates the target wheel cylinder pressure of each wheel cylinder according to the calculated target deceleration, and each wheel cylinder The feedback control so that the pressure of the target reaches the target wheel cylinder pressure of each wheel cylinder.

The electronic control unit 10 calculates the braking distance of the road surface based on the brake pedal pedal force detected by the pedaling force sensor 20 and the vehicle speed detected by the vehicle speed sensor 30.

The electronic control unit 10 detects the rain through the rain sensor 40 when the function of shortening the braking distance in the rain is activated, and if the rain is raining, the brake pedal effort and the vehicle speed sensor detected through the step sensor 20. The braking distance of the road surface is calculated on the basis of the vehicle speed detected through (30).

The electronic control unit 10 compares the calculated braking distance with the reference braking distance stored in the storage unit 60.

The electronic control unit 10 corrects the target braking force corresponding to the brake pedal foot force detected by the foot pressure sensor 20 according to the result of comparing the braking distances. If the braking distance calculated as a result of comparing the braking distances is longer than the reference braking distance, the electronic control unit 10 increases the target braking force corresponding to the brake pedal effort detected by the stepping force sensor 20 to have the same or similar braking distance. Let's do it.

3 is a control flowchart illustrating a braking force control method for a vehicle according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the electronic control unit 10 determines whether the brake pedal BP is operated by the driver (100).

When the brake pedal BP has been operated, the electronic control unit 10 detects the stepping force of the brake pedal BP operated by the driver through the stepping force sensor 20 (102).

The electronic control unit 10 detects rain water from the rain sensor 40 (104).

The electronic control unit 10 determines whether it is raining using the rainwater information detected by the rain sensor 40 (106).

If it is determined that the operation mode 106 is not in the rain, the electronic control unit 10 performs general braking control (108). The general braking control is a control for controlling the braking force of the vehicle based on the target braking force corresponding to the brake pedal pedal force detected by the pedaling force sensor 20.

On the other hand, if it is raining in the determination result of the operation mode 106, the electronic control unit 10 detects the speed of the vehicle through the vehicle speed sensor 30 (110), the brake pedal pedal effort and vehicle speed detected through the stepping force sensor 20 The braking distance of the driving road is calculated based on the vehicle speed detected by the sensor 30 (112).

The electronic control unit 10 compares the calculated braking distance with the reference braking distance stored in the storage 60 to determine whether the calculated braking distance is longer than the reference braking distance (114).

If the braking distance calculated as a result of the determination of the operation mode 114 is shorter than or equal to the reference braking distance, the electronic control unit 10 may determine that the vehicle is based on the target braking force corresponding to the brake pedal pedal force detected by the pedaling force sensor 20. A general braking control is performed to control the braking force (108).

On the other hand, when the braking distance calculated as a result of the determination of the operation mode 114 is longer than the reference braking distance, the target braking force corresponding to the brake pedal pedal force detected by the pedal force sensor 20 is increased to have the same or similar braking distance, and the increased target is increased. The uniaxial braking control for controlling the braking force of the vehicle based on the braking force is performed (116).

Hereinafter, the general braking control and the short braking control are selectively performed by the driver.

4 is a control flowchart of a braking force control method for a vehicle according to another exemplary embodiment of the present disclosure.

Referring to FIG. 4, the electronic control unit 10 determines whether the brake pedal BP is operated by the driver (200).

When the brake pedal BP has been operated, the electronic control unit 10 detects the stepping force of the brake pedal BP operated by the driver through the stepping force sensor 20 (202).

The electronic control unit 10 determines whether the braking distance shortening function is activated (204).

The electronic control unit 10 may determine whether the braking distance shortening function is activated or deactivated by checking a driver's command input through the input unit 50. In addition, the electronic control unit 10 checks the driver's command input through the input unit 50 and checks whether the rain sensor 40 is activated or deactivated to determine whether the braking distance shortening function is activated or deactivated. can do.

If the braking distance shortening function is deactivated as a result of the determination of the operation mode 204, the electronic control unit 10 controls the braking force of the vehicle based on the target braking force corresponding to the brake pedal pedal force detected by the stepping force sensor 20. General braking control is performed (206).

On the other hand, when the braking distance shortening function is activated as a result of the determination of the operation mode 204, the electronic control unit 10 detects the rain sensor 40 rain water (208).

The electronic control unit 10 determines whether it is raining using the rainwater information detected by the rain sensor 40 (210).

If it is determined that the operation mode 210 is not in the rain, the electronic control unit 10 performs general braking control (206).

On the other hand, if it is raining in the determination result of the operation mode 210, the electronic control unit 10 detects the speed of the vehicle through the vehicle speed sensor 30 (212), the brake pedal pedal effort and vehicle speed detected through the stepping force sensor 20 The braking distance of the driving road surface is calculated based on the vehicle speed detected by the sensor 30 (214).

The electronic control unit 10 compares the calculated braking distance with the reference braking distance stored in the storage unit 60 to determine whether the calculated braking distance is longer than the reference braking distance (216).

If the braking distance calculated as a result of the determination of the operation mode 216 is shorter or equal to the reference braking distance, the electronic control unit 10 performs general braking control (206).

On the other hand, if the braking distance calculated as a result of the determination of the operation mode 216 is longer than the reference braking distance, the target braking force corresponding to the brake pedal pedal force detected by the pedal force sensor 20 is increased to have the same or similar braking distance, and the increased target is increased. The uniaxial braking control for controlling the braking force of the vehicle based on the braking force is performed (218).

10: electronic control unit 20: step force sensor
30: vehicle speed sensor 40: rain sensor
50: input unit 60: storage unit

Claims (8)

In the braking force control device of the vehicle for calculating a target braking force corresponding to the stepping force of the brake pedal operated by the driver, and controlling the braking force of the vehicle based on the calculated target braking force,
A stepping sensor for detecting a stepping force of the brake pedal;
A vehicle speed sensor detecting a vehicle speed;
A storage unit storing a reference braking distance; And
And an electronic control unit for calculating a braking distance of the road surface based on the detected brake pedal response and vehicle speed, and correcting the target braking force according to a result of comparing the calculated braking distance with the stored reference braking distance. Braking force control device for the vehicle. The method of claim 1,
And the electronic control unit increases the target braking force when the calculated braking distance is longer than the stored reference braking distance. The method of claim 2,
Including rain sensor for detecting rain,
And the electronic control unit increases the target braking force when rainwater is detected through the rain sensor. The method of claim 2,
Including an input unit for receiving a command of the driver,
And the electronic control unit increases the target braking force when the braking distance shortening function activated by a driver's command input through the input unit is activated. The method of claim 1,
And the storage unit has a pre-stored braking force control device so that the reference braking distance corresponds to the vehicle speed and the brake pedal effort on the reference road surface. In the braking force control method of the vehicle for calculating a target braking force corresponding to the stepping force of the brake pedal operated by the driver, and controlling the braking force of the vehicle based on the calculated target braking force,
Detecting the pedaling force of the brake pedal,
Detect the speed of the vehicle,
Calculating the braking distance of the road surface based on the detected brake pedal effort and the vehicle speed;
Comparing the calculated braking distance with the reference braking distance stored in the storage unit,
And the target braking force is increased when the calculated braking distance is longer than the stored reference braking distance. The method of claim 6,
The target braking force increase may detect rainwater through a rain sensor and increase the target braking force when the rainwater is detected. The method of claim 6,
The target braking force increase method is to increase the target braking force when the braking distance shortening function activated by the command of the driver input through the input unit is activated.

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