KR20160049213A - Braking pressure control apparatus and method for vehicle - Google Patents

Abstract

The present invention comprises: a tire pressure sensing unit sensing air pressure of each wheel of a vehicle; and a braking pressure control module controlling braking pressure of a determined control wheel after determining one or more control wheels to be controlled among the wheels in accordance with each air pressure of the wheels sensed by the tire pressure sensing unit during cornering braking of a vehicle. The purpose of the present invention is to provide the braking pressure control apparatus for a vehicle, simultaneously controlling the braking pressure of the rear wheel and the front wheel of the vehicle to actively control a motion of the vehicle in a dangerous situation such as overturning.

Description

Technical Field [0001] The present invention relates to a braking pressure control apparatus and a braking pressure control apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle braking pressure control apparatus and method, and more particularly, to a vehicle braking pressure control apparatus and method for reflecting a tire air pressure on a running condition of a braking control and utilizing the same for wheel pressure control.

Cornering Braking Control (CBC), which is one of the additional functions of ABS, mitigates oversteer and improves stability by controlling braking pressure when turning the vehicle.

However, since the conventional CBC technique uses only the lateral acceleration / yaw rate / wheel slip information of the vehicle to control the braking pressure of the rear wheel, the yaw rate information may be measured differently from the actual condition depending on the road surface condition, There is a problem.

 For example, in the case of the conventional CBC technique, since the yaw rate is detected to be larger than the actual one in the case of the bank road surface or the mild slope of the slewing road, the braking pressure control of the rear wheel is excessively controlled to cause under braking or generate counter yaw rate There is a problem.

In addition, in the case of performing the braking control under the downward slope, the roll and the pitch motion are displayed simultaneously in addition to yaw motion in the vehicle. However, since the conventional CBC technique relieves only yaw, And the unstable of the vehicle due to the occurrence of the pitch and the driver's anxiety can not be solved.

In addition, the conventional CBC technique has a limitation in controlling the behavior of the vehicle when controlling only the braking pressure of the rear wheels.

The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 10-2005-0098637 (Oct. 12, 2005).

An object of the present invention is to provide a vehicle braking pressure control apparatus and method that reflect tire pressure of a tire to a performance condition of a braking control and apply it to wheel pressure control.

Another object of the present invention is to provide a vehicle braking system capable of compensating for the difference between the left and right tire air pressures when the yaw rate or the lateral acceleration is detected by reflecting the difference between the left and right tire pressures in the braking control, And to provide a control apparatus and method.

It is still another object of the present invention to provide a control method for controlling a braking pressure of a control wheel by predicting a roll and a pitch motion of a vehicle according to a difference in air pressure of each tire, The present invention provides a vehicle braking pressure control apparatus and method capable of eliminating instability of a vehicle due to occurrence of a pitch.

It is still another object of the present invention to provide a vehicle braking pressure control apparatus and method for simultaneously controlling the braking pressures of the rear wheels and the front wheels of a vehicle so as to positively control the behavior of the vehicle in a dangerous situation such as overturning.

A vehicle braking pressure control apparatus according to an aspect of the present invention includes: a tire inflation pressure sensing unit for sensing air pressure of each wheel of a vehicle; And a braking pressure control module for controlling the braking pressure for the control wheel determined after determining one or more control wheels to be controlled among the wheels according to the air pressures of the wheels sensed by the tire air pressure sensing part when the vehicle is in the swing braking state, And a control unit.

In the present invention, the braking pressure control module may include an arithmetic unit operable to calculate a pressure difference between a predetermined reference value and the air pressure of each of the wheels when the vehicle is in the swing braking state; A control wheel determining unit for predicting at least one of a yaw motion, a roll motion and a pitch motion of the vehicle according to a pressure difference of each wheel calculated by the calculation unit and determining the control wheel according to a prediction result; And a control amount determining unit for controlling a braking pressure for the control wheel determined by the control wheel determining unit according to a yaw change amount of the vehicle and a pressure difference between the respective wheels.

In the present invention, the control amount determining unit may be configured such that the front wheel wheel or the rear wheel on the inner side of the control wheel, which is determined by the control wheel determining unit, compensates the braking pressure control amount and controls the braking pressure control amount on each of the front wheel wheel or the rear wheel wheel The braking pressure is controlled additionally.

In the present invention, the reference value is the largest value among the air pressures of the wheels detected in the non-braking, non-turning and non-braking states of the vehicle.

In the present invention, the control wheel is characterized by at least one of a front wheel right wheel, a front wheel left wheel, a rear right wheel and a rear wheel left wheel of the vehicle.

In the present invention, it is determined whether or not the vehicle is in the orbiting braking operation. If the vehicle is in the orbiting braking operation, the slip ratio of the inner rear wheel is determined, and the control pressure control amount of the inner rear wheel is calculated in accordance with the determined slip ratio, And a braking pressure generating module for inputting the braking pressure to the pressure control module.

In the present invention, the braking pressure generating module may include a sudden braking determination unit for determining whether the vehicle is suddenly braked or not; A turning brake determination unit for determining whether the vehicle is in a turning brake; A slip rate calculating unit for calculating the slip rate; And a braking pressure generating unit for determining whether or not the vehicle requires turning control based on the slip ratio and generating a braking pressure control amount for the inner rear wheel in accordance with the determination result and inputting the braking pressure control amount to the braking pressure control module .

In the present invention, the slip ratio calculating section calculates the slip ratio using the speed and the vehicle speed of the rear inner rear wheel.

In the present invention, the braking pressure generating section generates the braking pressure control amount of the rear inner rear wheel using the yaw variation amount of the vehicle.

A vehicle braking pressure control method according to an aspect of the present invention determines whether or not a vehicle is in orbiting braking and determines a slip ratio of an inner rear wheel when the vehicle is in a braking operation, Generating a control pressure control amount of the control pressure; And controlling at least one control wheel to be controlled among the wheels according to the air pressures of the wheels sensed by the tire air pressure sensing unit at the time of braking the turning wheel and then controlling the braking pressure for the determined control wheels .

In the present invention, the step of controlling the braking pressure on the control wheel may include calculating a pressure difference between the preset reference value and the air pressure of each of the wheels during the braking operation, respectively; Estimating at least one of a yaw motion, a roll motion and a pitch motion of the vehicle according to a pressure difference between the wheels, and determining the control wheel according to a prediction result; And controlling the braking pressure on the control wheel in accordance with the yaw variation amount of the vehicle and the pressure difference between the respective wheels.

In the present invention, the step of controlling the braking pressure for the control wheel compensates for the braking pressure control amount of the turning inner front wheel or the inner rear wheel of the control wheel, and the turning outer front wheel or the turning outer rear wheel And the braking pressure is additionally controlled for each of them.

In the present invention, the reference value is the largest value among the air pressures of the wheels detected in the non-braking, non-turning and non-braking states of the vehicle.

In the present invention, the control wheel includes at least one of a front wheel right wheel, a front wheel left wheel, a rear right wheel and a rear wheel left wheel of the vehicle.

The present invention can compensate for the misjudgment of the yaw rate or the lateral acceleration by reflecting the tire air pressure to the conditions for performing the braking control and using it for the wheel pressure control, thereby preventing malfunction and transient control.

The present invention predicts the roll and pitch motions of the vehicle according to the difference in the air pressure of each tire and controls the braking pressure of the control wheel so that not only the yaw but also the roll and the pitch It is possible to eliminate the instability of the vehicle caused by the vehicle.

The present invention can simultaneously control the braking pressures of the rear wheels and the front wheels of the vehicle, and positively control the behavior of the vehicle in a dangerous situation such as overturning.

1 is a block diagram of a vehicle braking pressure control apparatus according to an embodiment of the present invention.
2 is a view showing air pressure of each wheel according to an embodiment of the present invention.
3 is a graph showing changes in braking pressure of each wheel according to an embodiment of the present invention.
4 is a view showing a roll motion change of a vehicle according to an embodiment of the present invention.
5 is a diagram illustrating a pitch motion change of a vehicle according to an embodiment of the present invention.
6 is a flowchart of a vehicle braking pressure control method according to an embodiment of the present invention.

Hereinafter, a vehicle braking pressure control apparatus and method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. Further, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the user, the intention or custom of the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a block diagram of a vehicle braking pressure control apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating air pressure of each wheel according to an embodiment of the present invention. FIG. 4 is a view showing a roll motion change of a vehicle according to an embodiment of the present invention. FIG. 5 is a view showing a pitch of a vehicle according to an embodiment of the present invention. Fig.

Referring to FIG. 1, an awake braking pressure control apparatus according to an embodiment of the present invention includes a braking sensing unit 10, a turning sensing unit 20, a wheel speed sensing unit 30, a braking pressure generating module 40, A braking pressure control module 60, and an actuator 70.

The braking sensing unit 10 senses whether or not the occupant brakes the vehicle. The braking sensing unit 10 may include a brake pedal switch installed on the brake pedal of the vehicle to sense the position of the brake pedal. In addition, the braking detection unit 10 may detect whether the vehicle is to be braked based on a vehicle speed change sensed by a vehicle speed sensor (not shown).

The turning detection unit 20 detects whether the vehicle is turning. A yaw rate sensor (not shown) for detecting a lateral acceleration sensor (not shown) for sensing the lateral acceleration of the vehicle or a yaw change amount of the vehicle may be employed as the turn detection unit 20. [ Here, the lateral acceleration may be directly sensed by the lateral acceleration sensor, but may also be estimated from the wheel speed sensed by the wheel speed sensing unit 30 and the speed of the wheel 80. [

The wheel speed sensing unit 30 senses the wheel speeds of the front wheel right wheel, the front wheel left wheel, the rear right wheel and the rear wheel left wheel of the vehicle, respectively.

The brake pressure generating module 40 determines whether or not the vehicle is turning by using at least one of the detection results of the brake sensing portion 10, the turning sensing portion 20 and the wheel speed sensing portion 30 If it is determined that the vehicle is in the orbiting braking state, the controller determines the slip ratio of the inner rear wheel, and then generates the control pressure control amount of the inner rear wheel according to the determined slip ratio to input into the braking pressure control module 60.

The braking pressure generating module 40 includes a rapid braking determination portion 41, a turning braking determination portion 42, a slip ratio calculating portion 43, and a braking pressure generating portion 44.

The rapid-motion determiner 41 determines whether the vehicle is currently in a rapid-braking state. The rapid braking determination unit 41 determines whether or not the braking pressure exceeds a preset braking pressure threshold value in the state where the braking sensing unit 10 detects the vehicle braking or whether the vehicle speed is decreased by exceeding a predetermined slope It is determined whether or not the vehicle is currently in a sudden braking state.

In a state in which the vehicle is judged to be in the fully-closed state by the quick-braking determination unit 41, the turning braking determination unit 42 determines whether or not the vehicle is currently turning braking. In this case, the orbiting braking determination unit 42 determines that the vehicle is currently in orbital braking if the lateral acceleration sensed by the lateral acceleration sensor exceeds a predetermined lateral acceleration threshold value.

When it is determined by the turning braking determination unit 42 that the vehicle is currently in the turning braking operation, the slip ratio calculating unit 43 calculates the slip ratio of the rear inner rear wheel. The slip ratio of the rear inner rear wheel is calculated using the difference between the wheel speed of the wheel 80 and the vehicle speed. Here, the wheel speed of the wheel 80 may be input from the wheel speed sensing unit 30, the vehicle speed may be input from the vehicle speed sensor, or may be estimated from the sensing result of the wheel speed sensing unit 30. [

The braking pressure generating unit 44 compares the slip rate of the rear inner rear wheel with a predetermined slip rate threshold value and determines that the swing braking control is necessary when the slip rate of the rear inner rear wheel is equal to or greater than the slip rate threshold value.

Usually, the slip of the rear inner rear wheel directly affects the yaw of the actual vehicle during the braking operation. Therefore, when the slip rate of the rear inner rear wheel during the braking operation is equal to or greater than the slip rate threshold value, the occurrence of the over-steering phenomenon can be immediately reduced by performing the swing braking control.

Therefore, the braking pressure generating unit 44 detects the braking pressure of the rear-wheel inner rear wheel when the braking-pressure generating unit 44 detects the braking-pressure change amount indicating the behavior of the vehicle and judges whether the braking- , And inputs the braking pressure control amount to the braking pressure control module (60).

The tire air pressure sensing unit 50 senses the air pressures of the front right wheel, the front left wheel, the rear right wheel, and the rear wheel left wheel.

The braking pressure control module 60 determines one or more control wheels to be controlled among the wheels according to the air pressures of the wheels sensed by the tire air pressure sensing unit 50 and then controls the braking pressure for the determined control wheels . Here, the control wheel may include a front wheel right wheel, a front wheel left wheel, a rear right wheel, and a rear wheel left wheel.

The braking pressure control module 60 includes a calculation unit 61, a control wheel determination unit 62, and a control amount determination unit 63.

The calculating unit 61 receives the air pressures of the front wheel right wheel, the front wheel left wheel, the rear right wheel and the rear wheel left wheel sensed by the tire air pressure sensing unit 50, detects the air pressure change amount of the turning inner wheel, It is determined whether the air pressure change amount is equal to or greater than a predetermined air pressure threshold value. In this case, if the air pressure change amount is equal to or greater than the air pressure threshold value, it can be understood that the air pressure is changed abruptly and the vehicle behavior is unstable.

Accordingly, the calculation unit 61 calculates the pressure difference between the predetermined reference value and the air pressure of each wheel. Here, the reference value is the largest value among the air pressures of the respective wheels detected in the non-braking, non-turning, and non-braking states of the vehicle.

For example, if the reference value is P_std and the air pressures of the front left wheel, the front right wheel, the rear left wheel and the rear right wheel are P1, P2, P3 and P4, respectively, P_std-P3 =? P3, and the pressure difference between the rear right wheel is P_std-P4 =? P4, and the pressure difference between the left wheel and the rear wheel becomes P_std- .

The control wheel determining unit 62 predicts at least one of the yaw motion, the roll motion, and the pitch motion of the vehicle according to the pressure difference of each of the wheels calculated by the calculating unit 61, and determines the control wheel according to the prediction result. Here, as described above, the control wheel can be selected as the control wheel to be controlled, that is, the front wheel right wheel, the front wheel left wheel, the rear right wheel, and the rear wheel left wheel.

For example, if ΔP1> 0 and ΔP3> 0 and ΔP2 <0 and ΔP4 <0, the air pressures of the turning inner front wheel and the inner rear wheel are reduced and the air pressures of the outer front wheel and the outer rear wheel are increased, It can be predicted that the roll motion has occurred.

That is, the control wheel determining unit 62 predicts at least one of the yaw motion, the roll motion, and the pitch motion of the vehicle based on the pressure difference of each of the wheels as described above, Wheel, the right rear wheel, and the rear left wheel as the control wheel.

When the control wheel is determined by the control wheel determining unit 62, the control amount determining unit 63 determines the braking pressure control amount for the control wheel. That is, the control amount determining unit 63 controls the braking pressure on the control wheels determined by the control wheel determining unit 62 based on the yaw change amount of the vehicle and the pressure difference between the respective wheels. In this case, The wheel or swivel inner rear wheel compensates for the braking pressure control amount and can additionally control the braking pressure for each of the outer swivel wheel or the outer swivel rear wheel of the control wheel.

Referring to FIG. 3, it can be seen that the braking pressure of the rear outer rear wheel and the braking pressure of the rear inner rear wheel are controlled in more detail ((a) -> (b)), and the turning outer front wheel and the turning inner front wheel (C) -> (d)), the braking pressure of the engine is controlled more precisely. 3, it can be seen that braking pressure control is performed not only on the inner front wheel and the rear inner wheel but also on the outer front wheel and the outer rear wheel.

As a result, the roll motion and the pitch motion of the vehicle can be controlled as shown in FIGS. 4 and 5A and 5B, respectively, so that the vehicle can more stably behave.

The actuator 70 is controlled by the braking pressure control amount for the front wheel right wheel, the front wheel left wheel, the rear right wheel, and the rear wheel left wheel inputted from the control amount determining unit 63. The front right wheel, the front wheel left wheel, Adjust the braking pressure of the left wheel independently.

Hereinafter, a vehicle braking pressure control method according to an embodiment of the present invention will be described in detail with reference to FIG.

6 is a flowchart of a vehicle braking pressure control method according to an embodiment of the present invention.

Referring to FIG. 6, first, the braking pressure generating module 40 determines whether braking intentions are sensed through the braking sensing unit 10, which senses whether a passenger brakes the vehicle (S10).

If it is determined in step S10 that the vehicle is to be braked, the braking pressure generating module 40 determines whether the vehicle is currently in the fully-operated state (S12). In this case, the braking pressure generating module 40 determines whether or not the vehicle is in a sudden braking state based on whether or not the braking pressure exceeds a preset braking pressure threshold value or whether or not the vehicle speed is reduced beyond a predetermined slope It can be judged.

As a result of the determination in step S12, if it is determined that the vehicle is in the final state, the braking pressure generating module 40 determines whether the vehicle is currently in the turning braking state based on whether the lateral acceleration detected by the lateral acceleration sensor exceeds a predetermined lateral acceleration threshold (S16).

If it is determined in step S16 that the vehicle is in the orbiting braking operation, the braking pressure generating module 40 calculates the slip ratio of the turning inner wheel using the difference between the wheel speed of the wheel 80 and the vehicle speed (S16) .

In this case, the braking pressure generating module 40 can determine that the swing braking control is necessary based on whether or not the slip ratio of the turning inner wheel exceeds a preset slip ratio threshold value.

On the other hand, the braking pressure generating module 40 acquires a yaw change amount of the vehicle (S18), and determines whether the obtained yaw change amount is equal to or greater than a preset yaw change amount threshold value (S20) , A braking pressure control amount for the inner rear wheel of the turning wheel is generated using the yaw change amount and the vehicle speed (S22).

Next, the tire air pressure sensing unit 50 acquires the air pressures of the front right wheel, the front left wheel, the rear right wheel, and the rear left wheel, respectively (S24).

The braking pressure control module 60 receives the air pressures of the front wheel right wheel, the front wheel left wheel, the rear right wheel and the rear wheel left wheel sensed by the tire air pressure sensing unit 50, (S26).

If the air pressure change amount of the turning inner wheel is equal to or greater than the air pressure threshold as a result of the determination in step 26, the predetermined difference between the preset reference value and the air pressure of each wheel is calculated (S28).

Then, the braking pressure control module 60 predicts at least one of yaw motion, roll motion and pitch motion of the vehicle according to the pressure difference of each wheel, determines a control wheel to be controlled according to the prediction result, The braking pressure control amount for the control wheel is determined according to the yaw change amount and the pressure difference of each wheel (S30).

Accordingly, the actuator 70 controls the braking pressure of the corresponding control wheel in accordance with the braking pressure control amount of the control wheel generated by the braking pressure control module 60 (S32).

In this embodiment, the tire air pressure is reflected in the execution condition of the braking control and is utilized for the wheel pressure control, so that even if the yaw rate or the lateral acceleration is erroneously detected, it can be compensated and the malfunction and transient control can be prevented.

In addition, according to the present embodiment, the roll and pitch motion of the vehicle are predicted in accordance with the difference in air pressure of each tire, and the braking pressure of the control wheel is controlled to control not only the yaw but also the roll and pitch ) Of the vehicle can be eliminated.

In addition, the present embodiment can simultaneously control the braking pressures of the rear wheels and the front wheels of the vehicle, and positively control the behavior of the vehicle in a dangerous situation such as rollover.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Accordingly, the true scope of the present invention should be determined by the following claims.

10:
20:
30: wheel speed sensing unit
40: Braking pressure generating module
41:
42:
43: Slip ratio calculating unit
44: Braking pressure generating section
50: tire air pressure sensing part
60: Braking pressure control module
61:
62: Control wheel determination unit
63:
70: Actuator
80: wheel

Claims (14)

A tire air pressure sensing unit for sensing air pressure of each wheel of the vehicle; And
A braking pressure control module for controlling at least one control wheel to be controlled among the wheels according to an air pressure of each of the wheels sensed by the tire air pressure sensing unit during the turning braking, Wherein the vehicle braking pressure control device comprises:
The braking pressure control module according to claim 1,
An arithmetic unit operable to calculate a preset reference value and a pressure difference between the air pressure of each of the wheels at the time of the turning brake;
A control wheel determining unit for predicting at least one of a yaw motion, a roll motion and a pitch motion of the vehicle according to a pressure difference of each wheel calculated by the calculation unit and determining the control wheel according to a prediction result; And
And a control amount determining unit for controlling a braking pressure for the control wheel determined by the control wheel determining unit in accordance with a yaw change amount of the vehicle and a pressure difference between each of the wheels.
3. The apparatus of claim 2, wherein the control amount determining unit
The front wheel or rear wheel on the inner side of the control wheel determined by the control wheel determining unit compensates the braking pressure control amount and further controls the braking pressure for each of the front wheel wheel or the rear wheel wheel on the outer side of the turning wheel And the vehicle braking pressure control device.
3. The vehicle braking pressure control device according to claim 2, wherein the reference value is the largest value among the air pressures of the wheels detected in the non-braking, non-braking and non-braking states of the vehicle.
The vehicle braking pressure control device according to claim 1, wherein the control wheel includes at least one of a front wheel right wheel, a front wheel left wheel, a rear right wheel, and a rear wheel left wheel of the vehicle.
The control method according to claim 1, further comprising the steps of: determining whether the vehicle is in a braking state, determining a slip ratio of the inner rear wheel if the vehicle is in a swing braking state, and generating a control pressure control amount of the inner rear wheel according to the determined slip ratio And a braking pressure generating module for inputting the braking pressure to the braking pressure control module.
The braking pressure generating module according to claim 6, wherein the braking pressure generating module
A sudden start determination unit for determining whether the vehicle is in a sudden braking state;
A turning brake determination unit for determining whether the vehicle is in a turning brake;
A slip rate calculating unit for calculating the slip rate; And
And a braking pressure generating unit for generating a braking pressure control amount for the inner rear wheel of the vehicle according to a result of the determination and inputting the generated braking pressure control amount to the braking pressure control module, The vehicle braking pressure control device.
The vehicle braking pressure control device according to claim 7, wherein the slip ratio calculating section calculates the slip ratio using the speed of the rear inner rear wheel and the vehicle speed.
The vehicle braking pressure control apparatus according to claim 7, wherein the braking pressure generating section generates the braking pressure control amount of the rear inner rear wheel using the yaw variation amount of the vehicle.
Determining a slip ratio of the inner rear wheel when the vehicle is in the orbiting braking operation and determining a control pressure control amount of the inner rear wheel according to the determined slip ratio; And
Determining one or more control wheels to be controlled among the wheels according to the air pressures of the wheels sensed by the tire air pressure sensing unit during the turning braking and then controlling the braking pressure on the determined control wheels Braking pressure control method.
11. The method of claim 10, wherein controlling the braking pressure on the control wheel
Calculating a preset reference value and a pressure difference between the air pressure of each of the wheels at the time of turning brake;
Estimating at least one of a yaw motion, a roll motion and a pitch motion of the vehicle according to a pressure difference between the wheels, and determining the control wheel according to a prediction result; And
And controlling the braking pressure for the control wheel in accordance with the yaw change amount of the vehicle and the pressure difference of each of the wheels.
12. The method of claim 11, wherein controlling the braking pressure on the control wheel
Wherein the braking pressure control amount of the inner wheel or inner wheel of the control wheel is compensated to control the braking pressure additionally to each of the outer wheel or outer wheel of the control wheel Control method.
12. The method according to claim 11, wherein the reference value is the largest value among the air pressures of the wheels detected in the non-braking, non-braking and non-braking states of the vehicle.
12. The method according to claim 11, wherein the control wheel includes at least one of a front wheel right wheel, a front wheel left wheel, a rear right wheel, and a rear wheel left wheel of the vehicle.

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