KR101950175B1 - Method for estimating road line information - Google Patents

Abstract

The present invention relates to a lane information estimating method, and more particularly, to a lane information estimating method capable of reducing an error of a secondary collision avoidance system and the like by normally estimating information of a lane even in an unstable vehicle behavior after a collision.
The method of estimating lane information according to the present invention comprises the steps of recognizing a lane of a road in which the vehicle is traveling through a camera sensor mounted on the vehicle; Confirming whether both lanes of the road are recognized in the recognized lane information; Calculating a first lateral deviation distance and a first lateral deviation angle for the recognized lane if the recognized lane is both lanes; Estimating a second lateral departure distance and a second lateral departure angle through a yaw rate sensor mounted on the vehicle when the recognized lane does not include any one lane on both lanes for a predetermined time; .

Description

[0001] METHOD FOR ESTIMATING ROAD LINE INFORMATION [0002]

The present invention relates to a lane information estimating method, and more particularly, to a lane information estimating method capable of reducing an error of a secondary collision avoidance system and the like by normally estimating information of a lane even in an unstable vehicle behavior after a collision.

According to the traffic accidents statistics of the last three years, 14% of the total deaths were caused by the second collision, and the mortality rate by the second collision was about 50%, which is about 3.3 times higher than the average mortality rate of 15.3% Respectively.

The reason for the high mortality rate due to the secondary collision is that the damage caused by the secondary collision is added to the damage after the primary collision, and the scale of the collision is increased.

As a result, in order to reduce the number of traffic accident deaths caused by the second collision, the second collision avoidance system has been actively studied since 2010.

The existing research on the second collision avoidance system is focused on avoidance through vehicle braking. However, in recent years, studies have been actively conducted on methods of applying braking and steering control to improve the avoidance performance by reducing the lateral deviation distance after the first collision.

Through these studies, it has been confirmed that braking distance and lateral deviation distance are important factors to increase survival rate after primary impact, and lateral deviation distance can be estimated through yaw rate and lateral acceleration.

However, if the position of the vehicle in the current lane can not be accurately detected in the lateral deviation distance estimation, the lateral deviation distance can not be accurately estimated. As a result, the secondary collision avoidance performance is also lowered.

Therefore, in order to improve the reliability of the Lane Keeping Assistance System (LKAS), which is a technique for accurately estimating lane information and vehicle position information in a secondary collision avoidance system, it is necessary to study the lane information estimation method used in LKAS in general. If the behavior of the vehicle is very unstable after the collision, normal estimation may not be possible.

Korean Patent No. 10-0901414 Korean Patent No. 10-2014-0078436

The object of the present invention is to provide a lane information estimation method which can accurately estimate lane information even after a collision by applying a nonlinear vehicle model and merging a camera sensor and a yaw rate sensor .

및 횡방향 속도

는 아래의 수식을 통해 계산되고, 아래 수식에서,

는 종방향 가속도,

는 횡방향 가속도,

는 요레이트이며,

상기 제2횡방향 이탈각

및 제2횡방향 이탈거리

는 아래의 수식을 통해 계산된다.

According to another aspect of the present invention, there is provided a lane information estimating method comprising the steps of repeatedly recognizing a lane of a road on which a vehicle is traveling through a camera sensor mounted on a vehicle at predetermined times or predetermined distances; Confirming whether both lanes of the road are recognized in the recognized lane information; Calculating a center line of the lane for both of the recognized lanes if the recognized lane is both lanes and calculating a first lateral deviation distance and a first lateral deviation angle of the vehicle according to the current vehicle position; When the recognized lane does not include any one of the lanes on both lanes for a predetermined time, the yaw rate sensor, the yaw rate sensor mounted on the vehicle, and the acceleration sensor detect the yaw rate, the longitudinal acceleration, and the lateral acceleration of the vehicle step; Calculating a longitudinal speed and a lateral speed of the vehicle using the detected yaw rate, longitudinal acceleration, and lateral acceleration of the vehicle; And estimating a second lateral deviation distance and a second lateral deviation angle of the vehicle using the calculated longitudinal velocity, lateral velocity, and yaw rate; , The longitudinal velocity of the vehicle

And lateral velocity

Is calculated by the following equation, and in the following equation,

The longitudinal acceleration,

Is the lateral acceleration,

Is the yaw rate,

The second lateral deviation angle

And the second lateral deviation distance

Is calculated by the following formula.

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According to the present invention, the lane information estimation method estimates lane information through fusion with a yaw rate sensor in an area where lane information is not continuously recognized due to a state of collision, The performance of the collision avoidance system can be improved.

1 is a view showing a lateral deviation distance and a lateral deviation angle.
2 is a diagram illustrating a method of recognizing a lane in a vehicle to which a camera sensor is applied and estimating a lateral departure distance and an angle of departure.
3 is an illustration of an example of a lane recognized from a front camera sensor after a collision of a vehicle.
4 is a flowchart of a lane information estimation method according to an embodiment of the present invention.
FIG. 5 is a flowchart of a second lateral deviation angle calculation process and a second lateral deviation angle calculation process performed by the yaw rate sensor according to an embodiment of the present invention.
FIG. 6 is a model graph of the deviation distance and the deviation angle using the yaw rate sensor according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a view showing a lateral deviation distance and a lateral deviation angle.

1, the lateral deviation distance is a lateral distance from the center of the lane to the center of gravity of the vehicle, and the lateral deviation angle is an angle formed by the tangent of the road and the steering angle of the vehicle.

Since the lateral deviation distance and the deviation angle must be converged to 0 in order to maintain the lane during running through the coordinated control of steering and braking after the collision and to avoid the secondary collision, Variable.

In order to extract the lateral deviation distance and the deviation angle, it is important to accurately recognize the lane information. For this, the lane is recognized through the lane image by applying the camera sensor.

2 is a diagram illustrating a method of recognizing a lane in a vehicle to which a camera sensor is applied and estimating a lateral departure distance and an angle of departure.

Referring to FIG. 2, it is assumed that the vehicle is running in the middle lane of three parallel lanes, and a point at which the lane is recognized is indicated by a small circle.

The distance between the recognition points of the lanes is narrower at the distance, and the distance between the recognition points of the lanes is wider at the distance. The lanes of the two lanes where the vehicle is traveling are connected by the solid lines to recognize the lanes.

를 계산하며, 차선의 중심 라인과 현재 차량의 헤딩각과의 차이각을 계산하여 횡방향 이탈각인

를 계산한다.After calculating the center line of the lane thus recognized, the difference between the center of gravity of the current vehicle and the center of gravity of the current vehicle is calculated,

And calculates a difference angle between the center line of the lane and the heading angle of the current vehicle to calculate the lateral deviation angle

.

However, if the camera sensor does not recognize one lane because of a collision or the like, the lateral deviation distance and the deviation angle can not be calculated.

3 is an illustration of an example of a lane recognized from a front camera sensor after a collision of a vehicle.

3, there is shown a situation in which a part of the left lane is not recognized as the vehicle is turned to the right after the collision.

In such a case, the lateral deviation distance and the lateral deviation angle can not be accurately calculated, and thus there may be an error in the lateral direction control to avoid the secondary impact.

In order to reduce these errors, it is desirable to calculate the lateral deviation distance and the deviation angle through fusion with the yaw rate sensor.

4 is a flowchart of a lane information estimation method according to an embodiment of the present invention.

Referring to FIG. 4, a lane information estimation method according to the present invention first carries out a step S101 of recognizing a lane of a road in which a vehicle is traveling through a camera sensor mounted on the vehicle.

This is a step that has already been described with reference to FIG. 2. In the normal operation, the lane of the lane in operation is recognized through the camera sensor, and the lane information including the lateral departure distance and the lateral departure angle is extracted.

Recognition of the lane through the camera sensor is repeatedly performed at predetermined times or predetermined distances, and it is checked whether both lanes are included in the recognized lane (S103).

If both lanes are recognized, the center line of the lane is calculated for both recognized lanes assuming that the vehicle is performing normal behavior, and the first lateral deviation distance and the first lateral distance And calculates a direction deviation angle (S105).

However, if the lane of either lane is not recognized for a predetermined time, it is determined that the vehicle behavior is abnormal, and the second lateral deviation distance and the second lateral deviation angle (S107).

The second lateral deviation distance and the second lateral deviation angle calculation process by the yaw rate sensor are shown in FIG.

5, in the lane information estimating method according to the present invention, the calculation of the second lateral deviation angle and the second lateral deviation angle by the yaw rate sensor is performed by first calculating the longitudinal velocity of the vehicle, the lateral velocity And detecting a yaw rate (S201).

The yaw rate sensor is a sensor that detects the yaw rate in the vertical axis direction of the vehicle and is a sensor applied to four-wheel steering control and the like.

When an AC voltage is applied to the vibrator of the yaw rate sensor, the vibrator is deformed and generates vibration, so that the vibrator is always oscillated left and right with a certain frequency. In this state, when the vehicle turns at a constant angular velocity, the detector of the sensor outputs an AC voltage while tilting in a direction perpendicular to the direction in which the vibration is applied.

The synchronous detection of the waveform of the alternating voltage thus generated detects the turning direction and its magnitude and outputs it as an analog signal. Also, the direction and magnitude of the lateral acceleration and the closing speed can be known by including the lateral acceleration sensor and the longitudinal acceleration sensor together.

In a sensor cluster of a vehicle to which EPB (Electronic Parking Brake) is applied, such a lateral acceleration sensor and a longitudinal acceleration sensor are installed in a yaw rate sensor.

The longitudinal velocity and the lateral velocity are calculated (S203) using the longitudinal acceleration, the lateral acceleration, and the yaw rate sensed from the vehicle lateral acceleration sensor, the longitudinal acceleration sensor and the yaw rate sensor (S203) (S205) of estimating the second lateral deviation angle and the second lateral deviation angle of the vehicle using the velocity, the lateral velocity and the yaw rate.

FIG. 6 is a model graph of the deviation distance and the deviation angle using the yaw rate sensor according to the present invention.

, 횡가속도

, 요레이트

를 알고 있을 때, 종방향 속도와 횡방향 속도는 다음과 같이 구해진다.Referring to FIG. 6, when a vehicle represented by a rectangle is substituted into a coordinate system,

, Lateral acceleration

, Yorate

, The longitudinal velocity and the lateral velocity are obtained as follows.

는 종방향 속도 변화량,

는 종방향 속도,

는 횡방향 속도 변화량,

는 횡방향 속도이다.In the above formula

The longitudinal velocity change amount,

Is the longitudinal velocity,

A lateral velocity change amount,

Is the transverse speed.

및 제2횡방향 이탈거리

는 아래의 수식을 통해 계산된다.Knowing the obtained longitudinal speed and lateral speed, the second lateral deviation angle

And the second lateral deviation distance

Is calculated by the following formula.

는 종방향 속도,

는 횡방향 속도,

는 요레이트를 의미한다.In the above formula,

Is the longitudinal velocity,

Is the lateral velocity,

Means yaw rate.

Returning to FIG. 5, when the second lateral deviation distance and the second lateral deviation angle are calculated, the calculated first lateral deviation distance and the first lateral deviation angle, The two lateral deviation distance and the second lateral deviation angle are applied to the next collision avoidance control (S109).

Through such a process, even when the vehicle behavior is unstable due to collision or the like, it is possible to accurately recognize the vehicle departure distance through application of the yaw rate sensor, thereby enhancing the reliability of the control system for the second collision avoidance.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments. Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope of the appended claims, The genius will be so self-evident. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (3)

Repeatedly recognizing a lane of a road on which the vehicle is traveling through a camera sensor mounted on the vehicle at every predetermined time or predetermined distance;
Confirming whether both lanes of the road are recognized in the recognized lane information;
Calculating a center line of the lane for both of the recognized lanes if the recognized lane is both lanes and calculating a first lateral deviation distance and a first lateral deviation angle of the vehicle according to the current vehicle position;
When the recognized lane does not include any one of the lanes on both lanes for a predetermined time, the yaw rate sensor, the yaw rate sensor mounted on the vehicle, and the acceleration sensor detect the yaw rate, the longitudinal acceleration, and the lateral acceleration of the vehicle step;
Calculating a longitudinal speed and a lateral speed of the vehicle using the detected yaw rate, longitudinal acceleration, and lateral acceleration of the vehicle; And
Estimating a second lateral deviation distance and a second lateral deviation angle of the vehicle using the calculated longitudinal velocity, lateral velocity, and yaw rate; Lt; / RTI >
The longitudinal speed of the vehicle

And lateral velocity

Is calculated by the following equation, and in the following equation,

The longitudinal acceleration,

Is the lateral acceleration,

Is the yaw rate,

The second lateral deviation angle

And the second lateral deviation distance

Is a lane information estimation method calculated through the following equation.

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