KR100774996B1 - Vehicle's attitude adjusting apparatus and method for the same - Google Patents

Abstract

A control method and an apparatus of a vehicle posture control device are provided to brake a vehicle in a straight forward direction by controlling a steering device according to the anti-lock braking operation state of the vehicle and the split state of the road during sudden braking so as to turn the steering angle of a wheel toward the side where friction force is low. A control method of a vehicle posture control device comprises the steps of: judging whether an anti-lock braking operation is asymmetrically performed for the left and right wheels or not in starting the anti-lock braking operation(S30); controlling the steering angle of the wheel by judging whether the anti-lock braking operation is generated in which one of the left and right wheels, if the anti-lock braking operation is asymmetrically performed(S40); and controlling the steering angle of the wheel according to the split-mu on state of the road if the anti-lock braking operation is symmetrically performed(S50).

Description

Control method of vehicle attitude control device and apparatus therefor {Vehicle's attitude adjusting apparatus and method for the same}

1 is an exemplary view showing a vehicle on a road surface having both frictional forces different from each other.

Figure 2 is a block diagram illustrating a control method of the vehicle attitude control apparatus according to an embodiment of the present invention.

3 is a simple operation flowchart of the vehicle attitude control device shown in FIG.

4 is a detailed operation flowchart of step S50 shown in FIG.

<Explanation of symbols for the main parts of the drawings>

100: vehicle attitude control device 110: braking control unit

120: steering cooperative control unit 121: anti-lock drive determination unit

122: road surface determination unit 123: first direction processing unit

124: second direction processing unit 125: third direction processing unit

200: vehicle memory 300: steering angle sensor

400: lateral acceleration sensor 500: vehicle speed sensor

600: yaw sensor 700: braking device

800: steering system

)라 칭함)에서 휠의 조향각을 차량이 직진방향으로 제동되도록 제어하는 차량 자세 제어 장치 및 그 제어 방법에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle attitude control apparatus and a control method thereof, and more particularly to an asymmetric friction road surface (hereinafter, split_mu).

The vehicle attitude control device and a control method for controlling the steering angle of the wheel so that the vehicle is braking in a straight direction.

When a vehicle is suddenly braked in a place where the frictional force on both sides of the road is different, the vehicle body tends to lean toward the higher frictional force.

1 is an exemplary view showing a vehicle on a road surface having both frictional forces different from each other.

Referring to FIG. 1, the vehicle is very dangerous because it is slid from the low friction side (the left ice of the vehicle shown in FIG. 1) and is directed to the high friction side (the right pavement of the vehicle shown in FIG. 1). .

Therefore, companies use anti-lock braking (ABS) to reduce the difference between the left and right braking force on the front wheels and to lower the braking force on the rear wheels, and to drive the steering system using additional sensors. Incorporating a number of electronic controls (such as Electronic Stability Control (ESC), Active Front Steering (AFS) and Active Roll Stabilization (ARS)) BACKGROUND ART Researches for controlling vehicle behavior with electronic cooperative control devices (such as vehicle dynamics management (VDM)) have been actively conducted.

These research trends show that individual systems, such as brakes, have limitations in controlling the car on special roads such as split mues.

As a result, individual systems such as vehicle stability control (ESC), active front wheel steering (AFS), and electric power steering (EPS) systems are integrated into the Unified Chassis Control (UCC) system. In addition, the necessity of developing logic to improve the stability of the vehicle by sharing sensor information and control information of individual systems has emerged.

The present invention has been devised for this need, and when the vehicle is braking in a place where the frictional force of both road surfaces is different (split mu or chess board), the direction of the steering angle of the wheel is controlled so that the vehicle is braked in the straight direction. An object of the present invention is to provide a vehicle attitude control device and a control method thereof.

Another object of the present invention is to provide a vehicle attitude control device and a method of controlling the steering angle of the wheel so that the vehicle brakes in a straight direction even when the frictional force of both road surfaces enters another place after the vehicle is braked.

According to an aspect of the present invention for achieving the above object, if the anti-lock braking drive is initiated, determining whether the disclosed anti-lock braking drive asymmetrically occurred with respect to the wheel on both the left and right, and the When anti-lock braking drive occurs asymmetrically, the first control step of controlling the steering angle of the wheel according to which of the left and right wheels has anti-lock braking drive, and the anti-lock braking drive When the symmetric occurs, the control method of the vehicle attitude control device comprising a second control step of controlling the steering angle of the wheel according to whether the road surface state is split mue.

Preferably, the second control step includes determining whether the road surface condition is split mu, and when the road surface state is split mu, comparing the difference in braking pressure between the left wheel and the right wheel for the road surface with a preset reference value. Controlling the steering angle of the wheel according to the comparison result.

More preferably, the step of controlling the steering angle of the wheel is calculated by comparing the braking pressure difference of the left and right wheels on the road surface with a predetermined reference value, as a result of the comparison, the brake pressure difference exceeds the predetermined reference value And controlling the steering angle of the wheel according to which of the left and right wheels has a greater braking pressure, and comparing the yaw value calculated in the vehicle with the braking pressure difference not exceeding a preset reference value. And controlling the wheel steering angle depending on whether the yaw rate value measured by the yaw sensor exceeds or falls below a preset range.

According to another aspect of the present invention, the left and right wheels of the vehicle by using a braking control unit that performs an anti-lock braking control function for the left and right wheels of the vehicle and the anti-lock braking driving information by the braking control unit. And a steering coordination control unit for controlling a steering angle of the steering coordination control unit, wherein the steering coordination control unit determines whether the anti-lock braking drive has occurred non-multi-layer on the left and right wheels of the vehicle based on the anti-lock braking drive information. When the anti-lock braking drive occurs asymmetrically, the steering angle of the wheel is controlled according to which of the left and right wheels the anti-lock braking drive occurs, and the anti-lock braking drive occurs symmetrically. The vehicle attitude control device is characterized in that for controlling the steering angle of the wheel according to whether the road surface state is split mue.

Preferably, the steering coordination control unit is an anti-lock braking drive determination unit for determining whether the anti-lock braking drive asymmetrically occurred with respect to the left and right wheels of the vehicle based on the anti-lock braking drive information; A first direction processor for controlling the steering angle of the wheel according to which of the left and right wheels has anti-lock braking driving, a road determining unit for determining whether the current road surface state is split mu, and a left side for the road surface And a second direction processor configured to compare the braking pressure difference between the wheel and the right wheel with a preset reference value and control the steering angle of the wheel according to the comparison result.

More preferably, the steering cooperative control unit may include a third direction processor configured to control the wheel steering angle according to whether a difference between the yaw rate value calculated in the vehicle and the yaw rate value measured by the yaw sensor exceeds or falls below a preset range. It includes more.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a block diagram illustrating a method of controlling a vehicle attitude control apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the vehicle electronic control system includes a vehicle attitude control device 100 for controlling a vehicle braking and a vehicle attitude during braking, and environmental information and vehicle driving information necessary for the vehicle attitude control device 100. Vehicle memory 200 to store, a plurality of sensors (steering angle sensor 300, lateral acceleration sensor 400, vehicle speed sensor 500, yaw sensor 600) for outputting the sensor value measured in the vehicle, braking It comprises an apparatus 700 and a steering apparatus 800.

The vehicle attitude control device 100 includes a brake control unit 110 that performs driving and anti-lock braking control of the brake device 700, and when the corresponding brake device 700 is driven, steering to correct the vehicle's attitude. And a steering cooperative control unit 120 for controlling the device 800.

The braking control unit 110 drives the braking device 700 according to a known braking control method in accordance with a braking control signal received from the outside, and is applied to both left and right wheels of the vehicle according to a known anti-lock braking control method. Performs an anti-lock braking function.

The steering cooperative control unit 120 includes an anti-lock determination unit 121 for determining anti-lock braking driving by the braking control unit 110, and a road surface determination unit 122 for determining whether the current road surface state is split mu. And a first direction processing unit 123 and a second direction processing unit for outputting a control signal to the steering apparatus 800 based on the determination result of the anti-lock determination unit 121 and / or the road surface determination unit 122. 124, the third direction processing unit 125 is configured.

First, the anti-lock determining unit 121 determines whether the anti-lock driving has occurred asymmetrically with respect to the left and right wheels of the vehicle by using the anti-lock braking driving information by the braking control unit 110.

When anti-lock braking occurs symmetrically with respect to both wheels of the vehicle by the anti-lock determination unit 121, the road determination unit 122 determines whether the current road surface state is split mu (asymmetric road surface).

At this time, the road surface determination unit 122 is implemented to determine whether or not split mu according to the lateral acceleration measured by the lateral acceleration sensor 400 according to an embodiment of the present invention, the present invention is not limited thereto.

When the anti-lock braking occurs asymmetrically with respect to both wheels of the vehicle by the anti-lock determination unit 121, the first direction processor 123 may be configured to determine which of the wheels has anti-lock braking. Outputs a control signal that controls the steering angle of the wheel.

In detail, the first direction processor 123 outputs a control signal for controlling the steering angle of the wheel to the left when anti-lock braking occurs on the left wheel, and sets the steering angle of the wheel to the right when anti-lock braking occurs on the right wheel. Outputs a control signal controlled by

When the current road surface state is determined to be split mu by the road surface determination unit 122, the second direction processor 124 compares the difference in braking pressure of both wheels on the road surface with a predetermined reference value, and determines the wheel according to the comparison result. Outputs a control signal to control the steering angle of.

In detail, the second direction processor 124 outputs a control signal for controlling the steering angle of the wheel to the right when the braking pressure of the left wheel is greater than a predetermined reference value than the braking pressure of the right wheel, and the braking pressure of the right wheel is increased. When the braking pressure of the left wheel is greater than a predetermined reference value, a control signal for controlling the steering angle of the wheel to the left is output.

The third direction processor 125 compares the yaw value calculated by the vehicle and the yaw sensor 600 measured by the vehicle when the difference in braking pressure of both wheels is equal to or less than a predetermined value as a result of the comparison of the second direction processor 124. A control signal for controlling the steering angle of the wheel is output according to whether the difference in the rate value exceeds or falls below the preset range.

In detail, the third direction processor 125 controls the steering angle of the wheel to the right when the difference between the yaw rate value calculated in the vehicle and the yaw rate value measured by the yaw sensor 600 exceeds a preset range. And outputs a control signal for controlling the steering angle of the wheel to the left when the difference of each value is not within the preset range.

3 is a simple operation flowchart of the vehicle attitude control device 100 according to an embodiment of the present invention.

Referring to FIG. 3, the braking control unit 110 controls the braking device 700 in response to a braking control signal input from the outside, and controls the braking device 700 against the left and right wheels of the vehicle based on a known anti-lock control method. -Lock braking control is performed (S10).

Next, the anti-lock determination unit 121 determines whether the anti-lock braking is driven by the braking control unit 110 (S20).

As a result of the determination in step S20, when anti-lock braking is driven by the braking control unit 110, it is determined whether the currently driven anti-lock braking is asymmetrically operated with respect to the left and right wheels (S30).

As a result of the determination in step S30, when the activated anti-lock braking is asymmetrically operated with respect to the left and right wheels, the first direction processor 123 may be configured to determine which of the left and right wheels has anti-lock braking. The steering angle of the wheel is controlled (S40).

In detail, the first direction processor 123 outputs a control signal for controlling the steering angle of the wheel to the left when the anti-lock braking driving occurs on the left wheel, and the steering angle of the wheel when the anti-lock braking driving occurs on the right wheel. Output a control signal to control to the right.

As a result of the determination in step S30, when the operated anti-lock braking is symmetrically operated with respect to the left and right wheels, the steering coordination control unit 120 controls the steering angle of the wheel according to whether the current road surface is split mu (S50). ).

Detailed operation of the step S50 is shown in FIG.

Referring to FIG. 4, the road surface determination unit 122 determines whether the current road surface is a split mu (S51).

As a result of the determination in S51, when the current road surface is split mu, the second direction processor 124 calculates contact pressures of the left and right wheels in order to control the steering angle of the wheel according to the braking pressures of the left and right wheels (S52).

Next, the second direction processor 124 determines whether the difference between the calculated braking pressures of the left and right wheels exceeds the predetermined reference value (S53).

As a result of the determination in step S53, when the calculated difference in braking pressure exceeds a predetermined reference value, the second direction processor 124 controls the steering angle of the wheel according to which of the left and right wheels has a greater braking pressure (S54). ).

In detail, the second direction processor 124 outputs a control signal for controlling the steering angle of the wheel to the left when the braking pressure of the left wheel is greater than the right wheel, and the steering angle of the wheel when the braking pressure of the right wheel is greater than the left wheel. Output a control signal to control to the right.

As a result of the determination in step S53, when the calculated difference in braking pressure does not exceed a preset reference value, the third direction processor 125 calculates the yaw calculated in the vehicle to perform steering control according to the yaw rate value of the vehicle. The difference between the rate value and the yaw rate value measured by the yaw sensor 600 is calculated (S55).

Next, the third direction processor 125 controls the steering angle of the wheel according to whether the difference calculated by the step S55 exceeds or falls below a preset range (S56).

In detail, when the difference calculated by the step S55 exceeds the preset range, the third direction processor 125 outputs a control signal for controlling the steering angle of the wheel to the right, and the calculated difference falls below the preset range. In this case, a control signal for controlling the steering angle of the wheel to the left is output.

The present invention has been described above with reference to preferred embodiments and many specific variations. However, those skilled in the art will understand that many other embodiments other than those specifically described also fall within the spirit and scope of the invention.

According to the present invention, the next vehicle control device controls the steering device by using the anti-lock braking of the vehicle during sudden braking and whether the road is split or not, thereby turning the steering angle of the wheel in a direction of low friction and braking the vehicle straightly. It has the effect of making it possible.

On the other hand, when the vehicle enters the split mu or chess board after braking, the vehicle may not be able to determine the lower frictional force by anti-lock braking.

Therefore, even if the anti-lock braking is performed on both the left and right wheels at the present time, the vehicle control device of the present invention corrects and controls the steering angle of the wheel by using the road determining unit, the second steering control unit, and the third steering control unit. In addition, there is an effect that the vehicle can be braking straight by supplementing the case where the vehicle does not know whether the vehicle is behaving only by anti-lock braking.

Claims (6)

When the anti-lock braking drive is started, determining whether the disclosed anti-lock braking drive occurs asymmetrically with respect to the wheels on both the left and right sides; A first control step of controlling a steering angle of the wheel according to which of the left and right wheels the anti-lock braking drive occurs when the anti-lock braking drive occurs asymmetrically; And a second control step of controlling the steering angle of the wheel depending on whether the road surface state is split mu, when the anti-lock braking drive occurs symmetrically. The method of claim 1, wherein the second control step Determining whether the road surface condition is split mute, And when the road surface state is split mu, comparing the difference in braking pressure between the left and right wheels on the road surface with a preset reference value and controlling the steering angle of the wheel according to the comparison result. Control method of the posture control device. The method of claim 2, wherein controlling the steering angle of the wheel Calculating a difference in braking pressure between the left and right wheels on the road surface and comparing the brake pressure with a predetermined reference value; As a result of the comparison, when the difference in braking pressure exceeds a predetermined reference value, controlling the steering angle of the wheel according to which of the left and right wheels has a greater braking pressure; As a result of the comparison, when the braking pressure difference does not exceed a preset reference value, the wheel steering angle may be adjusted depending on whether the difference between the yaw rate value calculated in the vehicle and the yaw rate value measured by the yaw sensor exceeds or falls below the preset range. And controlling the vehicle attitude control apparatus. A braking control unit which performs an anti-lock braking control function for both the left and right wheels of the vehicle; A steering cooperative control unit for controlling steering angles of the left and right wheels of the vehicle by using the anti-lock braking driving information by the braking control unit, The steering coordination control unit On the basis of the anti-lock braking driving information, it is determined whether anti-lock braking driving has occurred in a large scale with respect to the left and right wheels of the vehicle, and when the anti-lock braking driving occurs asymmetrically, which of the left and right wheels Controls the steering angle of the wheel according to whether the anti-lock braking drive has occurred in the wheel, and controls the steering angle of the wheel according to whether or not the road surface state is the split mute when the anti-lock braking drive occurs symmetrically. Vehicle attitude control device. The method of claim 4, wherein the steering cooperative control unit An anti-lock braking drive determination unit for determining whether anti-lock braking drive has occurred asymmetrically with respect to the left and right wheels of the vehicle based on the anti-lock braking drive information; A first direction processor configured to control a steering angle of the wheel according to which of the left and right wheels has an anti-lock braking drive; A road decision unit determining whether the current road condition is split mu, And a second direction processing unit which compares a difference in braking pressure between the left wheel and the right wheel on the road surface with a preset reference value and controls the steering angle of the wheel according to the comparison result. The method of claim 5, wherein the steering cooperative control unit And a third direction processor configured to control a wheel steering angle according to whether a difference between the yaw rate value calculated in the vehicle and the yaw rate value measured by the yaw sensor exceeds or falls below a preset range. Device.

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