KR101339245B1 - Active brake force assist control systen and control method thereof - Google Patents

Abstract

The present invention discloses a control method of an active brake system to provide a stable braking distance by compensating for wheel pressure when a fade generation condition is detected in a state where braking control is performed by operation of a brake pedal.
The present invention includes the steps of detecting vehicle information including the pedal force of the brake pedal, the speed for each wheel, the deceleration speed, and the temperature of the brake pad; Applying a set map to extract a braking control value according to the pedal effort of the brake pedal to perform braking control, and determining whether the temperature of the brake pad has risen to a fade generation temperature set as a map; Determining a correction control value according to a fade occurrence when the temperature of the brake pad is raised to the fade generation temperature; And applying the correction control value determined by the fade generation to the braking control value determined by the pedal force of the brake pedal to perform the braking control.

Description

ACTIVE BRAKE FORCE ASSIST CONTROL SYSTEN AND CONTROL METHOD THEREOF

The present invention relates to a brake system for a vehicle, and more particularly, an active brake system for compensating a wheel pressure to provide a stable braking distance when a fade generation condition is detected in a state where braking control is performed by operation of a brake pedal. And a control method thereof.

The vehicle is provided with a brake system for decelerating or stopping the vehicle speed as needed in the running state.

The brake device generates a braking force by converting the kinetic energy of the vehicle into thermal energy and radiating it into the atmosphere by using friction force.

The brake device is operated by the brake cylinder mounted on the caliper by hydraulic or pneumatic pressure generated by the booster according to the driver's brake pedal operation, and the brake cylinder moves the pads so as to closely adhere to both sides of the disc-shaped disc, thereby generating friction braking force. Let's go.

The braking performance according to the operation of the brake pedal is one of the basic performance requirements for securing the driver's safety. Therefore, a brake device using a hybrid unit has been applied according to the high performance of the vehicle.

In response to demands for improved fuel economy and tightening emission regulations, eco-friendly vehicles including hybrid vehicles, fuel cell vehicles, electric vehicles, and plug-in electric vehicles are being provided.

Unlike general internal combustion engine vehicles, eco-friendly vehicles cannot use the negative pressure of the engine at all times to boost the brake booster, so a separate booster system has been developed and applied.

In the current eco-friendly vehicle, a booster device of a hydraulic pump type and a booster device of a vacuum pump type are applied, and an operation of the booster device is performed by driving a motor.

When continuous braking is performed as the vehicle travels a long downhill road (alpine), the temperature rises rapidly due to long-term friction between the brakes and the pads, and thus causes a fade phenomenon that reduces or loses the braking force. Let's do it.

As can be seen from the relationship between the temperature and the braking force shown in FIG. 3, when the continuous braking using the brake is performed for a long time, if the temperature between the disk and the pad is excessively increased, the friction coefficient between the disk and the pad is lowered. Accordingly, the braking performance is lowered, thereby increasing the braking distance.

For example, it may be slightly different depending on the type of vehicle, but it can be seen that the friction coefficient is decreasing as the temperature between the disk and the pad starts to exceed approximately 500 ° C.

When the temperature between the disk and the pad is excessively increased by continuous braking using the brake for a long time, the temperature of the brake oil is increased to generate bubbles in the brake oil.

Therefore, the friction coefficient is lowered due to excessive increase in temperature between the disk and the pad, and when the air bubbles are generated in the brake oil, the braking distance is increased, so that the driver can generate the same braking force only by pressing the brake pedal more strongly.

However, most of the drivers are difficult to recognize the fade conditions, thereby pressing the brake pedal in the usual conditions, and as a result increase the braking distance can cause accidents such as collision, fall, rollover.

An object of the present invention is to improve the above problems, and an object thereof is to provide stable braking performance by compensating wheel pressure when a fade generation condition is detected in a state in which braking control is performed by operation of a brake pedal of a vehicle.

The present invention seeks to provide safe operation by requiring shoulder parking when the temperature between the disc and the pad exceeds the set temperature of the fade condition in the state where braking control is performed by the operation of the brake pedal.

According to the present invention, if a continuous driving is detected in the state where the temperature between the disc and the pad requires a shoulder parking by exceeding the set temperature of the fade generation condition, a fire may occur in the brake pad. We want to provide safe operation by running.

Features according to an embodiment of the present invention is a vehicle information detection unit for detecting information including the pedal force of the brake pedal, the speed for each wheel, deceleration, the temperature of the brake pad; After the brake control value according to the pedal power of the brake pedal is extracted from the set map, the smart booster is operated to execute the braking control corresponding to the pedaling force.When the brake pad temperature reaches the fade generation temperature set as the map, the correction control value is determined. A control unit for performing braking control by further including a correction control value according to a fade generation in the braking control value determined by the pedal force of the brake pedal; Smart booster for generating a torque corresponding to the brake step by the drive of the motor in accordance with the control signal of the controller; A master cylinder generating hydraulic pressure by the torque applied from the smart booster to provide friction between the disk and the pad; Provided is an active brake system including a pressure detector for detecting a hydraulic pressure discharged from a master cylinder and providing the pressure to a controller.

The vehicle information detection unit may include: a brake detection unit which provides a control unit with information on whether the brake pedal is operated and foot pedal information; A wheel speed detector mounted at a predetermined position of each wheel to provide speed control information for each wheel to a controller; An acceleration detector for providing deceleration information of the vehicle to the controller; It may include a pad temperature detector for providing the temperature information of the brake pad to the controller.

The controller may be configured as a dedicated ECU for controlling the smart booster or may be applied as an ECU of the electronic parking brake system.

The controller may set a braking control value according to a fade generation temperature and a brake pedal effort of each brake pad according to the vehicle type and the brake pad.

The controller adjusts the braking control value according to the speed of each wheel, the deceleration of the vehicle, and the discharge oil pressure of the master cylinder provided by the pressure detector in the state of executing the braking force control corresponding to the foot pedal of the brake pedal by operating the smart booster. The discharge pressure of the master cylinder can be adjusted.

The controller may output a warning message in a predetermined format set through the display unit when the temperature of the brake pad is close to the fade generation temperature set in the map.

The control unit may provide the same braking distance to the brake response by applying a correction control value as long as the braking distance is reduced due to the decrease in the friction coefficient due to the fade generation and the bubbles of the brake oil.

When the brake pad temperature reaches the fade generation temperature and the braking control to which the correction control value is applied is performed, the controller may warn the fade generation through the display unit and request the parking of the vehicle.

The controller stops the braking control applying the correction control value when the temperature between the disk and the pad approaches the pad ignition temperature due to continuous driving and braking in a parking request condition, and reduces the engine output torque and the low speed by interworking the engine control unit and the shift control unit. The gearbox can be combined to provide a forced stop.

In addition, a feature according to an embodiment of the present invention is a process for detecting vehicle information including the pedal force of the brake pedal, the speed for each wheel, deceleration, the temperature of the brake pad; Applying a set map to extract a braking control value according to the pedal effort of the brake pedal to perform braking control, and determining whether the temperature of the brake pad has risen to a fade generation temperature set as a map; Determining a correction control value according to a fade occurrence when the temperature of the brake pad is raised to the fade generation temperature; Provided is a control method of an active brake system including applying a correction control value determined by a fade occurrence to a braking control value determined by the pedal force of the brake pedal to execute the braking control.

In a state in which braking control is performed using the braking control value according to the pedal force of the brake pedal, the braking control value may be adjusted according to the speed of each wheel, the deceleration of the vehicle, and the discharge hydraulic pressure.

When the temperature of the brake pad is close to the fade generation temperature set as the map, a warning message may be output in a predetermined format.

The correction control value determined by the generation of the fade may provide a braking distance corresponding to the brake effort as a braking distance that is long due to a decrease in the friction coefficient and bubbles of the brake oil.

When the brake pad temperature reaches the fade generation temperature and the braking control to which the correction control value is applied is performed, a warning message requesting fade generation and parking may be output in a predetermined format.

If the temperature between the disc and the pad approaches the pad ignition temperature due to continuous driving and braking in the parking request, the braking control using the correction control value can be stopped, and the forced output can be induced by combining the engine output torque reduction and the low speed shift stage. have.

As described above, the present invention can provide stable braking performance by actively compensating the wheel pressure when the temperature between the disk and the pad is raised to the fade generation condition in the state where the braking control is executed.

In addition, the present invention outputs a warning message when the temperature between the disk and the pad exceeds the fade condition when the brake pedal is operated by the operation of the brake pedal. Can be prevented.

In addition, the present invention is to prevent the occurrence of fire due to the overheating of the pad by running the forced parking by the engine torque and the shift stage control when the driving is maintained in the state where the disk and the pad temperature exceeds the fade generation condition is required for shoulder parking Can be.

1 is a view showing a schematic configuration of an active brake system according to an embodiment of the present invention.
2 is a flowchart schematically illustrating a control procedure of an active brake system according to an exemplary embodiment of the present invention.
3 is a graph illustrating a relationship between brake temperature and braking force for each vehicle.

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

The present invention can be embodied in various different forms, and thus the present invention is not limited to the embodiments described herein.

1 is a view schematically showing an active brake system according to an embodiment of the present invention.

Referring to FIG. 1, the present invention provides a vehicle information detector 110, a controller 120, a display 130, a smart booster 140, a master cylinder 150, a brake cylinder 160, and a pressure detector 170. Include.

The vehicle information detecting unit 110 detects and provides the control unit 120 including information including the pedaling force of the brake pedal operated by the driver, the speed for each wheel, the deceleration speed, and the temperature of the brake pad.

The vehicle information detector 110 includes a brake pedal detector 111, a wheel speed detector 112, an acceleration detector 113, and a pad temperature detector 114.

The brake detector 111 detects whether the brake pedal is operated by the driver and the pedal force of the brake pedal and provides information about the brake pedal to the controller 120.

The wheel speed detector 112 is mounted at a predetermined position of each wheel to detect a speed for each wheel and provide information to the controller 120.

The acceleration detector 113 detects the deceleration of the vehicle according to the braking control and provides information about the deceleration to the controller 120.

The pad temperature detector 114 detects the temperature of the brake pad that generates the braking force by closely contacting the disks at both sides during braking control and provides information about the brake pad to the controller 120.

The controller 120 may be configured as a dedicated ECU for controlling the smart booster 140 or may be applied as an ECU of an electronic parking brake system.

The controller 120 sets a braking control value according to the fade generation temperature and the brake pedal effort of each brake pad according to the vehicle type and the brake pad as a map.

The controller 120 extracts a braking control value according to the pedal power of the brake pedal from the set map by applying the speed of each wheel and the deceleration of the vehicle when the pedal information of the brake pedal is detected by the vehicle information detector 110. By operating the smart booster 140 so that the braking force corresponding to the stepping force can be generated.

The control unit 120 operates the smart booster 140 to generate a braking force corresponding to the stepping force of the brake pedal, the speed of each wheel, the deceleration speed of the vehicle, and the master cylinder 150 provided by the pressure detector 170. By adjusting the braking control value in accordance with the discharge hydraulic pressure of the smart booster 140 to adjust the pressure discharged from the master cylinder 150.

In addition, the controller 120 analyzes the temperature of the brake pad to determine whether the pad temperature reaches the fade generation temperature set in the map, and approaches the fade generation temperature. For example, when the fade generation temperature reaches about 95%, the cluster is clustered. A warning message is output through the display unit 130 installed in the warning unit to enter a standby mode of braking control.

The warning message may be output in a warning light or a predetermined format, and the message may be output through the transmission of a warning sound.

The controller 120 determines a correction control value when the temperature of the brake pad reaches the fade generation temperature set in the map, and then further includes a correction control value according to the fade generation in the braking control value determined by the brake pedal's pedaling force. 140).

That is, the same braking distance can be provided for the brake response by applying a correction control value as long as the braking distance is increased due to the decrease in the friction coefficient due to the fade generation and the bubble generation of the brake oil.

When the brake pad temperature reaches the fade generation temperature and the braking control applying the corrected braking control value is executed, the controller 120 outputs a fade occurrence status as a warning message through the display unit 130 installed in the cluster. Requires shoulder parking.

The controller 120 stops the braking control applying the corrected braking control value when the temperature between the disk and the pad approaches the pad ignition temperature when the continuous driving and braking are executed despite the parking request. The shift stage of the engine output torque is coupled to the shift control unit 310 at a low stage so that the vehicle can be forcibly stopped.

Then, the display unit 130 installed in the cluster outputs a warning message for forced stop of the vehicle in a predetermined format.

In other words, the braking distance is prevented by the braking control by applying the compensation braking control value according to the fade occurrence. However, excessive temperature rise between the brake disc and the pad may cause the pad to ignite or break the brake system. Adjust it so that the shoulder parking drops the temperature between the disc and the pad.

The smart booster 140 generates a torque corresponding to the brake effort by driving the motor to operate the master cylinder 150.

The master cylinder 150 is operated by the torque applied from the smart booster 140 to generate the hydraulic pressure.

The brake cylinder 160 is operated by the hydraulic pressure supplied to the master cylinder 150 to move the pads installed on both sides of the disk toward the disk so as to closely contact the disk, so that a braking force is generated.

The pressure detector 170 detects the hydraulic pressure discharged from the master cylinder 160 and provides information about the hydraulic pressure to the controller 120.

The operation of the present invention including the functions as described above is executed as follows.

The brake pedal detection unit 111 included in the vehicle information detection unit 110 in the ecology in which the vehicle to which the present invention is applied is provided to the control unit 120 by detecting the pedal force of the brake pedal operated by the driver and providing the wheel speed detection unit ( 112 detects the speed for each wheel and provides it to the controller 120, and the acceleration detector 113 detects the deceleration of the vehicle and provides it to the controller 120 (S101).

In this case, the control unit is configured as a dedicated ECU for controlling the smart booster 140 or applied to the ECU of the electronic parking brake system, the control unit for setting the braking control value according to the fade generation temperature and brake pedal power of the brake pedal for each vehicle type and brake pad The vehicle 120 analyzes vehicle information provided from the vehicle information detection unit 110 (S102) and determines whether a pedal force of a brake pedal, which is a braking request of the driver, is detected (S103).

In step S103, the controller 120 extracts the braking control value according to the braking response from the set map by applying the speed for each wheel and the deceleration of the vehicle when the foot pedal pressure of the brake pedal, which is the driver's braking request, is detected. By operating the smart booster 140 (S104).

The smart booster 140 generates a torque corresponding to the braking control value to operate the master cylinder 150, and generates hydraulic pressure according to the operation of the master cylinder 150 to operate the brake cylinder 160.

Therefore, the pads provided on both sides of the disk closely contact the disk to generate a braking force (S105).

The control unit 120 operates the smart booster 140 to generate a braking force corresponding to the stepping force of the brake pedal, the speed of each wheel, the deceleration speed of the vehicle, and the master cylinder 150 provided by the pressure detector 170. The pressure discharged from the master cylinder 150 is adjusted by adjusting the output torque of the smart booster 140 by adjusting the braking control value according to the discharge hydraulic pressure of the.

The controller 120 detects the temperature of the brake pad through the pad temperature detector 114 (S106) and determines whether the pad temperature reaches the fade generation temperature set in the map (S107).

In step S107, when the temperature of the pad is close to the fade generation temperature, for example, when the fade generation temperature reaches about 95%, the controller 120 outputs a warning message through the display unit 130 installed in the cluster to warn the driver. Then enters the standby mode of braking control.

The warning message may be output in a warning light or a predetermined format, and the message may be output through the transmission of a warning sound.

In step S107, the controller 120 determines a correction control value when the temperature of the brake pad reaches the fade generation temperature set in the map (S108).

In addition, the control unit 120 further includes a correction control value according to the generation of the fade in the braking control value determined by the pedal force of the brake pedal to operate the smart booster 140 (S109).

That is, the same braking distance can be provided for the brake response by applying a correction control value as long as the braking distance is increased due to the decrease in the friction coefficient due to the fade generation and the bubble generation of the brake oil.

Therefore, since the torque output from the smart booster 140 is output as the torque to which the correction control value according to the fade is applied, the operating force of the master cylinder 150 is pressurized to discharge the hydraulic pressure of the state higher than the normal condition and thus the pad And close to the disk with a greater force (S110).

Therefore, the braking distance, which is prolonged by the fade generation due to the temperature rise of the disk and the pad, can be restored to the normal braking distance.

When the brake pad temperature reaches the fade generation temperature and the braking control to which the correction control value is applied is performed, the controller 120 outputs a fade occurrence status as a warning message through the display unit 130 installed in the cluster. Requires shoulder parking.

The controller 120 determines whether the temperature between the disk and the pad is close to the pad ignition temperature when continuous driving and braking is performed despite the parking request (S111). The braking control to which the correction control value is applied is stopped, and a warning message is output in a predetermined format set through the display unit 130 installed in the cluster (S112).

Then, the control unit 120 to reduce the engine output torque by interlocking the engine control unit 210, coupled to the shift stage low speed by interlocking the shift control unit 310 to reduce the engine output torque and low speed shift stage. By executing the control of the vehicle to be forced to stop (S113).

Then, the display unit 130 installed in the cluster outputs a warning message for forced stop of the vehicle in a predetermined format.

In other words, the braking distance is prevented by the braking control by applying the compensation braking control value according to the fade occurrence. However, excessive temperature rise between the brake disc and the pad may cause the pad to ignite or break the brake system. Adjust it so that the shoulder parking drops the temperature between the disc and the pad.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

110: vehicle information detection unit 120: control unit
130: display unit 140: smart booster
150: master cylinder 160: brake cylinder
170: pressure detector

Claims (15)

A vehicle information detection unit detecting information including a pedal pedal effort, a speed for each wheel, a deceleration speed, and a temperature of a brake pad;
After the brake control value according to the pedal power of the brake pedal is extracted from the set map, the smart booster is operated to execute the braking control corresponding to the pedaling force.When the brake pad temperature reaches the fade generation temperature set as the map, the correction control value is determined. A control unit for performing braking control by further including a correction control value according to a fade generation in the braking control value determined by the pedal force of the brake pedal;
Smart booster for generating a torque corresponding to the brake step by the drive of the motor in accordance with the control signal of the controller;
A master cylinder generating hydraulic pressure by the torque applied from the smart booster to provide friction to the disk and the pad;
A pressure detector detecting the hydraulic pressure discharged from the master cylinder and providing the pressure to the controller;
Including;
And the controller warns the occurrence of a fade through the display unit when the brake pad temperature reaches the fade generation temperature and applies the correction control value, and requests parking of the vehicle. The method of claim 1,
The vehicle information detection unit may include: a brake detection unit which provides a control unit with information on whether the brake pedal is operated and foot pedal information;
A wheel speed detector mounted at a predetermined position of each wheel to provide speed control information for each wheel to a controller;
An acceleration detector for providing deceleration information of the vehicle to the controller;
A pad temperature detector configured to provide temperature information of a brake pad to a controller;
Active brake system comprising a. The method of claim 1,
The controller is configured as a dedicated ECU for controlling the smart booster or active brake system, characterized in that applied to the ECU of the electronic parking brake system. The method of claim 1,
The control unit is an active brake system, characterized in that the braking control value according to the fade generation temperature for each vehicle type, the brake pads and the pedaling force of the brake pedal is set as a map. The method of claim 1,
The controller adjusts the braking control value according to the speed of each wheel, the deceleration of the vehicle, and the discharge oil pressure of the master cylinder provided by the pressure detector in the state of executing the braking force control corresponding to the foot pedal of the brake pedal by operating the smart booster. Active brake system, characterized in that for adjusting the discharge pressure of the master cylinder. The method of claim 1,
And the control unit outputs a warning message in a predetermined format set through the display unit when the temperature of the brake pad is close to the fade generation temperature set in the map. The method of claim 1,
The control unit provides an equal braking distance to the brake effort by applying a correction control value as long as the braking distance is reduced due to a decrease in the friction coefficient due to the fade generation and bubbles in the brake oil. delete The method of claim 1,
The controller stops the braking control applying the correction control value when the temperature between the disk and the pad approaches the pad ignition temperature due to continuous driving and braking in a parking request condition, and reduces the engine output torque and the low speed by interworking the engine control unit and the shift control unit. Active brake system, characterized in that to provide a forced stop by combining the shift stage. Detecting vehicle information including a pedal pedal effort, a speed for each wheel, a deceleration speed, and a temperature of a brake pad;
Applying a set map to extract a braking control value according to the pedal effort of the brake pedal to perform braking control, and determining whether the temperature of the brake pad has risen to a fade generation temperature set as a map;
Determining a correction control value according to a fade occurrence when the temperature of the brake pad is raised to the fade generation temperature;
Performing braking control by applying a correction control value determined by generating a fade to the braking control value determined by the pedal force of the brake pedal;
Control method of an active brake system comprising a. The method of claim 10,
Active brake system, characterized in that for controlling the discharge pressure by adjusting the braking control value according to the speed of each wheel, the deceleration of the vehicle, the discharge oil pressure in the state of performing the braking control with the braking control value according to the pedal force of the brake pedal Control method. The method of claim 10,
And outputting a warning message in a predetermined format when the temperature of the brake pad approaches a fade generation temperature set as a map. The method of claim 10,
The control method of the active brake system, characterized in that the correction control value determined by the fade generation is provided as a braking distance corresponding to the braking effort to provide a braking distance that is long due to the reduction of the friction coefficient and bubbles of the brake oil. The method of claim 10,
And outputting a warning message requesting fade generation and parking in a predetermined format when the brake pad temperature reaches the fade generation temperature and the braking control to which the correction control value is applied is executed. 15. The method of claim 14,
In the parking request, if the temperature between the disk and the pad approaches the pad ignition temperature due to continuous driving and braking, stopping the braking control applying the correction control value and inducing a forced stop by combining the engine output torque reduction and the low speed shift stage. The control method of the active brake system characterized in that.

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