KR102465472B1 - Brake system and method for vehicle - Google Patents

Abstract

The present invention relates to a braking system and a braking method for a vehicle capable of increasing braking performance and safety of a vehicle by reducing a braking distance and securing a smooth steering force when the vehicle comes to a sudden stop. A braking system for a vehicle according to the present invention includes a control unit that implements a control logic for preventing wheel lock and slip when the vehicle is braking, and receives the control of the control unit when a brake pedal is operated to apply brake hydraulic pressure. ABS (Anti-Lock Brake System) braking device including a hydraulic control valve for controlling; The operation is controlled by the control unit, and in a situation where the ABS braking device is operated, the hydraulic control valve is operated whenever the hydraulic control valve is repeatedly opened to generate a reverse torque in a direction opposite to the traveling direction of the vehicle to reduce the wheel speed. It is characterized in that it comprises a;

Description

Brake system and method for vehicle

The present invention relates to a braking system and a braking method for a vehicle, and more particularly, to a braking system and braking system for a vehicle that can reduce a braking distance during sudden braking of a vehicle and increase braking performance and safety of a vehicle by securing a smooth steering force it's about how

BACKGROUND ART In general, a brake system is a device that generates a braking force in a traveling vehicle to prevent the vehicle from moving by itself, and is usually operated by hydraulic pressure generated and supplied from a master cylinder according to an operation of a brake pedal.

That is, the conventional braking device includes a brake pedal that the driver steps on to generate braking force, a booster that amplifies or enlarges the force of stepping on the brake pedal, a master cylinder that converts the pressing force of the brake pedal into hydraulic pressure, and , a brake body that receives hydraulic pressure from the master cylinder and generates a substantial braking force, and the like.

Therefore, when the driver presses the brake pedal, the pedaling force is converted into hydraulic pressure by the master cylinder and supplied to the brake body through the brake pipe, oil distributor, and brake hose, and the hydraulic pressure supplied to the brake body is converted to the brake shoe or brake By compressing the pad with a drum or disk, braking force is generated by the frictional force, thereby stopping the vehicle in motion.

However, in a vehicle using the conventional braking device as described above, the wheels stop rotating due to frictional force during sudden braking, but the vehicle slides in the driving direction due to the acceleration force and the braking distance becomes longer, thereby shortening the life of the wheel and further Severely, there was a problem in that material and human damage occurred.

On the other hand, an anti-lock brake system (ABS) braking device is installed in a conventional vehicle to prevent a slip from occurring due to locking of the wheels during sudden braking.

This ABS brake system receives the control logic of the ABS ECU to prevent locking and slipping of the wheels during braking, a speed sensor that detects the wheel speed and provides it to the ABS ECU, and the ABS ECU when operating the brake pedal. It consists of a hydraulic control valve that controls the braking hydraulic pressure, and a brake that brakes the wheels with the hydraulic pressure supplied from the hydraulic control valve.

If the ABS brake system configured as described above is used, when the brake is braked through the hydraulic control valve according to the operation of the brake pedal, the ABS ECU controls the hydraulic pressure of the hydraulic control valve based on the signal from the speed sensor to brake. Braking can be implemented while preventing wheel lock that causes slip.

However, in a conventional vehicle equipped with such an ABS braking system, the loss of steering stability of the vehicle can be prevented to some extent by controlling the brake pressure set during sudden braking of the vehicle, particularly when the vehicle is suddenly braked on a slippery road surface. However, there was a limit to shortening the braking distance of the vehicle within a short time when a panic brake situation in which the vehicle abruptly stopped suddenly occurs, and as a result, it is difficult to effectively prevent a sudden collision of the vehicle. .

Korean Patent Publication No. 1998-049939 (1998.09.15)

The present invention has been devised to solve the above problems, and the technical problem to be solved in the present invention is a drive mounted on a vehicle at the timing when the hydraulic valve is opened according to the control logic of the ABS in a situation in which the ABS is operated during sudden braking of the vehicle. The braking distance can be reduced by reducing the speed of the vehicle wheel by generating a reverse torque from the motor in the direction opposite to the vehicle's moving direction. To provide a system and a braking method.

A vehicle braking system according to the present invention for solving the above technical problem includes a control unit implementing a control logic for preventing wheel lock and slip during braking of the vehicle, and the brake pedal when the brake pedal is operated. ABS (Anti-Lock Brake System) braking device including a hydraulic control valve for controlling the braking hydraulic pressure under the control of the controller; The operation is controlled by the control unit, and in a situation where the ABS braking device is operated, the hydraulic control valve is operated whenever the hydraulic control valve is repeatedly opened to generate a reverse torque in a direction opposite to the traveling direction of the vehicle to reduce the wheel speed. It is characterized in that it comprises a;

Here, the driving motor may be installed on the non-driven wheel side of the vehicle to be controlled to reversely rotate only the non-driven wheel.

In addition, the driving motor may be a motor that is basically installed on the driving wheel side in the case of an electric vehicle.

In this case, in the electric vehicle, the control unit may convert and control the output voltage and current waveform of the inverter controlling the output of the driving motor in a direction for reversely rotating the driving motor.

In addition, the driving motor may be an in-wheel motor mounted on a driving wheel in an electric vehicle.

Meanwhile, the method for braking a vehicle according to the present invention includes the steps of (a) starting an anti-lock brake system (ABS) braking device by manipulating a brake pedal; (b) decelerating the wheel speed by reversely rotating the driving motor in a direction opposite to the traveling direction of the vehicle whenever the hydraulic control valve is repeatedly opened according to the control logic in a situation in which the ABS braking device is operated; characterized in that

In this case, in step (b), the driving motor may be controlled to reduce the wheel speed by reversely rotating the non-driven wheel of the vehicle.

In addition, in the step (b), in the case of an electric vehicle, the driving motor may be controlled to reversely rotate the driving wheel of the vehicle to reduce the wheel speed.

In this case, in the case of an electric vehicle, the output voltage and current waveforms of the inverter controlling the output of the driving motor may be converted and controlled in a direction for reversely rotating the driving motor through the control unit.

According to the braking system and braking method of a vehicle according to the present invention, the hydraulic valve is opened by the ABS control logic while the ABS is operated by sudden braking while the vehicle is driving, and the non-driving wheel of the vehicle is at a timing when the braking hydraulic pressure is decreased. Alternatively, the driving motor mounted on the driving wheel generates a reverse torque in the direction opposite to the traveling direction of the vehicle, thereby increasing the deceleration effect of the vehicle wheel, thereby greatly contributing to reducing the braking distance of the vehicle and sudden braking of the vehicle. It can also contribute to improving steering power in situations. In particular, if the driving motor that generates the reverse torque is applied only to the rear wheel side, which is a non-driven wheel of the vehicle, there is an effect that the wheel speed of the rear wheel can be reduced faster without directly affecting the driving shaft of the vehicle.

In addition, in the case of an electric vehicle, since a motor for generating the driving force of the vehicle is basically mounted, there is no need to additionally mount the driving motor on the driving shaft of the vehicle wheel. The effect can be obtained, and in such an electric vehicle, the same effect can be obtained by converting and controlling the output voltage and current waveforms of the inverter that control the output of the motor in the direction of reverse rotation of the motor.

1 is a device configuration diagram showing a position in which a drive motor of the present invention is mounted in a vehicle equipped with an ABS braking device.
2 is a configuration diagram illustrating a state in which a driving motor is installed on a non-driven wheel side of an internal combustion engine vehicle as an embodiment of the present invention.
3 is a configuration diagram showing a state in which a driving motor is installed on a driving wheel side of an electric vehicle according to another embodiment of the present invention;
4 is a graph showing the wheel speed distribution according to the braking time when the ABS braking system is operated, and is a graph showing the time when the reverse rotation operation of the drive motor starts when the hydraulic control valve is opened and the wheel speed is increased;
5 is a flowchart sequentially illustrating a vehicle braking method according to the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention.

However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. In addition, it is to be noted that throughout the detailed description, parts denoted by the same reference numerals mean the same components.

Hereinafter, a vehicle braking system and a braking method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a device configuration diagram showing a position in which a driving motor of the present invention is mounted in a vehicle equipped with an ABS braking device, and FIG. 2 is a configuration showing a state in which the driving motor of the present invention is installed on the non-driven wheel side of an internal combustion engine vehicle it is do In addition, FIG. 3 is a configuration diagram showing a driving motor installed on the driving wheel side of an electric vehicle according to another embodiment of the present invention, and FIG. 4 is a graph showing the wheel speed distribution according to braking time when the ABS braking device is operated. , It is a graph showing the time when the reverse rotation operation of the driving motor starts when the hydraulic control valve is opened and the wheel speed is increased.

The vehicle braking system according to the present invention is a vehicle equipped with an ABS (Anti-Lock Brake System) braking system in parallel with braking of the vehicle by the ABS braking system in a situation in which the ABS braking system is operated by manipulating the brake pedal. It is a braking system capable of reducing the braking distance of a vehicle by decelerating the speed of a driving wheel or a non-driving wheel of the vehicle by reversely rotating the driving motor 150 in a direction opposite to the traveling direction of the vehicle.

FIG. 1 shows a position in which a driving motor generating reverse rotation torque is mounted when the vehicle is braked in a vehicle equipped with an ABS braking device.

As shown in FIG. 1 , the ABS braking device mounted on the vehicle implements a control logic that prevents the wheel from locking and the wheel from slipping during braking of the vehicle. ECU (Electronic Control Unit) 101, the wheel speed sensor 103 that detects the speed of the wheels 120 and 140 and provides it to the ECU 101, and the control of the ECU 101 when the brake pedal 102 is operated The hydraulic control valve 104 for controlling the braking hydraulic pressure provided to each wheel 120 and 140 through the brake line 110, and the disc brake 105 for braking the wheels 120 and 140 with the hydraulic pressure supplied from the hydraulic pressure control valve 104 ) is included.

Therefore, when the driver operates the brake pedal 102 to brake through the hydraulic control valve 104 , the ECU 101 controls the hydraulic pressure of the hydraulic pressure control valve 104 based on the signal from the wheel speed sensor 103 . By controlling this, it is possible to implement braking while preventing wheel lock that causes slip during braking.

The present invention is mounted on the wheel axle of the vehicle to assist the braking force by the ABS braking system in a vehicle equipped with such an ABS braking system, and the wheel 140 (rear wheel) is moved by the control of the ECU 101 of the vehicle. A driving motor 150 for generating a reverse rotation torque in a direction opposite to the direction is mounted. The operation of the driving motor 150 is started together with the operation of the ABS braking device. Hereinafter, the ECU 101 will be collectively referred to as a control unit.

FIG. 2 shows a state in which a driving motor is installed on a non-driving wheel in an internal combustion engine vehicle as an embodiment of a vehicle braking system according to the present invention.

Referring to FIGS. 2 and 1 , the braking system for a vehicle according to the present invention includes a control unit 101 that implements a control logic for preventing wheel locking and slipping during vehicle braking, and a brake pedal 102 when the brake pedal 102 is operated. An ABS braking device including a hydraulic pressure control valve 104 for adjusting braking hydraulic pressure under the control of the control unit 101, the operation is controlled by the control unit 101, and hydraulic pressure adjustment in a situation in which the ABS braking system is operated It is configured to include a driving motor 150 that is operated every time the valve 104 is repeatedly opened to generate a reverse torque in a direction opposite to the traveling direction of the vehicle to reduce the speed of the wheel 140 .

In the internal combustion engine vehicle as shown in FIG. 2 , the driving motor 150 may be installed on a side of a non-driven wheel (eg, a rear wheel) to which engine power is not directly applied. That is, the driving motor 150 is connected through the gear unit 160 on the wheel shaft 142 of the non-driven wheel 140 , and the driving motor 150 is connected and installed with the battery 130 mounted on the vehicle. By doing so, the control unit 101 transmits a reverse rotation driving signal to the driving motor 150 to reversely rotate the non-driven wheel 140 in a situation in which the ABS braking device is operated when the vehicle is braked. By reducing the wheel speed of the vehicle, the braking distance of the vehicle can be reduced.

In this way, in an internal combustion engine vehicle, the driving motor 150 is installed on the non-driven wheel 140 side of the vehicle so that reverse torque is generated only in the non-driven wheel 140 during braking, so that the front side driving wheel 120 of the vehicle. It is possible to quickly reduce only the wheel speed of the non-driven wheel 140 without affecting the .

Meanwhile, FIG. 3 shows a state in which the driving motor 150 of the present invention is installed in an electric vehicle that runs using the driving force of the motor as another embodiment of the braking system according to the present invention.

As shown in FIG. 3 , since a motor for generating the driving force of the vehicle is already basically installed as a power source in an electric vehicle (including a hybrid vehicle), when the braking system of the present invention is operated in an electric vehicle, reverse rotation A motor that is basically mounted on a vehicle and serves as an actual engine can be utilized as the driving motor 150 of the present invention without the need to additionally install a driving motor for generating torque.

In this case, since the motor basically mounted on the electric vehicle is mounted on the driving wheel (eg, front wheel) side of the vehicle, the existing driving motor mounted on the wheel shaft 122 of the driving wheel 120 ( 150) can be used to implement a braking system.

With this configuration, the control unit 101 transmits a reverse rotation driving signal to the driving motor 150 that is basically installed on the driving wheel 120 side in a situation where the ABS braking device is operated when braking the electric vehicle, and the driving wheel ( By rotating 120 in the reverse direction, the reverse rotation torque of the motor can be directly applied to the non-driven wheel 140 portion, thereby reducing the wheel speed of the driving wheel 120 to reduce the braking distance of the vehicle.

At this time, since the electric vehicle controls the output of the driving motor 150 through the inverter 170 , when the braking system of the present invention is operated in the electric vehicle, the output voltage of the inverter 170 through the control unit 101 . And by converting and controlling the current waveform in the direction of reverse rotation of the driving motor 150, the speed of the driving wheel 120 can be reduced in the same manner as described above, thereby reducing the braking distance of the vehicle. .

In addition, an in-wheel motor in which the motor is built into the wheel of the vehicle may be used as the driving motor 150 for generating a reverse rotation torque to the wheel in the electric vehicle. Since the in-wheel motor has high energy efficiency by directly transmitting the driving force to the wheel without a separate mechanical medium, when the braking system is implemented by generating a reverse rotation torque to the in-wheel motor, the battery 130 consumption is reduced. Energy efficiency can be increased.

On the other hand, FIG. 4 is a graph showing the change in the speed (V) of the non-driven wheel according to the braking time (T) when the ABS braking system is operated. When the hydraulic control valve 104 is opened and the wheel speed is increased, the driving motor ( 150) shows the starting point of the reverse rotation operation.

When the speed of the wheel is controlled by the ABS braking device when the vehicle is braked, the wheel speed is not reduced constantly, but the hydraulic control valve 104 repeatedly opens and closes according to a predetermined control logic, resulting in the graph form shown in FIG. Similarly, when the hydraulic pressure control valve 104 is closed, the hydraulic pressure for braking the wheel increases to decrease the wheel speed, and when the hydraulic pressure control valve 104 is opened, the hydraulic pressure decreases and the wheel speed increases again. In addition, the braking of the vehicle is achieved by repeating such a control process very briefly and quickly.

In the present invention, each time point (point A) at which the hydraulic control valve 104 is opened in a section (section L) in which the wheel speed is increased by opening the hydraulic control valve 104 during the operation of the ABS braking system as shown in FIG. ) by applying a driving signal capable of generating a reverse torque to the driving motor 150 in a direction opposite to the traveling direction of the vehicle through the control unit 101, thereby increasing the wheel speed due to the opening of the hydraulic control valve 104 At (L), the wheel speed may be reduced by the reverse rotation of the driving motor 150 .

5 is a flowchart sequentially illustrating a process in which a vehicle is braked using the braking system of the present invention having the above-described configuration.

Referring to FIG. 5 , in the method of braking a vehicle according to the present invention, first, when the driver presses the brake pedal while the vehicle is driving and braking of the vehicle is started (S211), the controller 101 determines whether the ABS operates (S212) ), if the ABS does not need to operate, the drive motor 150 maintains a stop state (S221), and if the ABS operation is required, the ABS controls the operation of the hydraulic control valve 104 according to a predetermined control logic. Thus, the ESC generates hydraulic pressure for braking (S213), and the opening and closing of the In-Valve and Out-Valve occurs repeatedly at a quick moment.

On the other hand, when the hydraulic control valve 104 is closed in such a situation that the ABS is operated, the braking hydraulic pressure is increased to increase the pressure (braking pressure) of the wheel (S214), and when the pressure of the wheel is increased in this way, the speed of the wheel is is decreased (S215).

Conversely, when the hydraulic pressure control valve 104 is opened, the brake hydraulic pressure is reduced to reduce the wheel pressure (braking pressure) (S216), and when the wheel pressure is reduced in this way, the wheel speed is increased again (S217).

In a situation in which the ABS is operating, the operation of closing and opening the hydraulic control valve 104 is quickly repeated in a short time according to the control logic by the control unit 101. At this time, the control unit 101 controls the hydraulic control valve 104 ) is repeatedly opened, the driving motor 150 is synchronized and a driving signal is transmitted to the driving motor 150 to generate a reverse torque to control the driving. (S218)

In this way, when the driving motor 150 is rotated in reverse, a reverse torque is applied to the non-driven wheel (the driving wheel in the case of an electric vehicle) (S219), thereby reducing the wheel speed. (S220)

And, this series of processes occurs repeatedly while the ABS operates, and when the ABS operation stops, the driving motor 150 maintains a stopped state (S221).

In addition, the series of control processes as described above may be performed in the same manner not only in an electric vehicle equipped with a motor but also in a general internal combustion engine vehicle. The wheel speed can be reduced by generating a reverse rotation in the direction and applying a reverse torque to the non-driven wheel or the driving wheel. As a result, since the additional wheel speed can be reduced compared to the braking situation caused by the general ABS operation, it is possible to obtain the effect of greatly reducing the braking distance when braking the vehicle.

Although preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to these specific embodiments, and those skilled in the art will appropriately change within the scope described in the claims of the present invention. this will be possible

101: control unit (ECU) 102: brake pedal
103: wheel speed sensor 104: hydraulic control valve
105: disc brake 110: brake line (hydraulic line)
120: drive wheel (front wheel) 130: battery
140: non-driven wheel (rear wheel) 142: wheel axle
150: drive motor 160: gear unit

Claims (9)

ABS comprising a control unit for implementing control logic to prevent wheel lock and slip when braking of a vehicle, and a hydraulic pressure control valve for adjusting brake hydraulic pressure under the control of the control unit when a brake pedal is operated Anti-Lock Brake System);
A driving motor installed in connection with a battery mounted on the vehicle, the operation of which is controlled by the control unit;
The control unit is
In a situation in which the ABS braking device is operated, the hydraulic control valve is opened and the reverse rotation driving signal opposite to the traveling direction of the vehicle is applied to the driving motor at the opening time of the hydraulic control valve for each section in which the wheel speed of the vehicle is increased. By applying the application, the braking system of the vehicle according to claim 1, wherein the speed of the wheel is reduced by the reverse rotation of the driving motor to reduce the braking distance of the vehicle.

The braking system of claim 1 , wherein the driving motor is installed on a non-driven wheel side of the vehicle.
The braking system of claim 1 , wherein the driving motor is a motor installed on a driving wheel side of an electric vehicle to drive the wheel.
The braking system for a vehicle according to claim 3, wherein the controller converts and controls an output voltage and current waveform of an inverter that controls an output of the driving motor in an electric vehicle in a direction for reversely rotating the driving motor.
4. The braking system of claim 3, wherein the driving motor is an in-wheel motor mounted on a driving wheel.
6. A method for braking a vehicle using the vehicle braking system according to any one of claims 1 to 5, comprising:
(a) starting the operation of the ABS (Anti-Lock Brake System) braking system by manipulating the brake pedal;
(b) decelerating the wheel speed by reversely rotating the driving motor in a direction opposite to the traveling direction of the vehicle whenever the hydraulic control valve is repeatedly opened according to the control logic in a situation in which the ABS braking device is operated; How to brake a vehicle.
7. The method of claim 6, wherein in step (b), the driving motor reversely rotates a non-driven wheel of the vehicle to reduce the wheel speed.
The method of claim 6 , wherein, in the step (b), when the driving motor is an electric vehicle, the driving wheel of the vehicle is reversely rotated to reduce the wheel speed.
The vehicle according to claim 8, wherein in the step (b), in the case of an electric vehicle, an output voltage and current waveform of an inverter controlling an output of the driving motor is converted and controlled in a direction for reversely rotating the driving motor. of the braking method.

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