KR20020097354A - Method for deciding lane secession - Google Patents

Abstract

PURPOSE: A deciding method of a separation of a lane is provided to process a signal rapidly and to minimize the lost of lane information when a vehicle is traveled in a straight course. CONSTITUTION: An image processing area is set by using preset two circles. The distance between centers of the circles are equal and the centers exist on a lane. An outline of each processing area is detected among inputted images. A distribution chart of the outline is examined. The lane is modeled to a straight line by using pixels of main distribution areas. The existence of the straight line inside the processing area is checked. The separation of the lane is decided when the straight line doesn't exist inside the processing area. Thereby, the processing speed is quickened and the lost of lane information is reduced.

Description

Lane Departure Determination Method {METHOD FOR DECIDING LANE SECESSION}

The present invention relates to a lane departure prevention system, and more particularly, to a lane departure determination method capable of high-speed signal processing and minimizing loss of lane information when a vehicle travels on a straight road.

Recently, various systems for safe and convenient vehicle operation have been developed along with various advances in technology, and among these systems, to prevent accidents caused by neglect of the driver's forward attention due to prolonged driving, drowsy driving, or using a mobile phone, etc. There is a lane departure prevention system.

The lane departure prevention system measures a location of a lane and a vehicle on a driving road and warns when the vehicle leaves the lane or automatically drives a steering actuator to adjust a driving direction of the vehicle. And a photographing unit, and an image processing unit for extracting the position and travel directions of the vehicle on the lane from the captured road image, and optionally, an alarm generating unit for generating an alarm when the vehicle leaves the lane as a result of the processing of the image processing unit. Or a steering control unit for generating a steering command for preventing lane departure from current position data of the vehicle, and a steering actuator driven according to the steering command.

In the lane departure prevention system having such a configuration, in order to determine lane departure, the position and traveling directions of the vehicle on the lane must be extracted from the image of the driving road photographed. Not

Therefore, in recent years, a method of reducing the amount of computation by setting an area to be processed in advance has been sought. In the conventional method of setting an image processing area, the area including the estimated position of the lane is varied for every frame of the input image. There is a method of setting an image processing area or fixing a trapezoidal processing area.

However, since the former method needs to set the image processing area every frame, it is difficult to expect the actual amount of computation to be reduced, and the latter method may cause the loss of lane information.

In addition, since both methods require a separate complicated operation for lane departure determination, there is a limit in implementing a high speed lane departure warning device.

Accordingly, the present invention is to solve the above problems, an object of the present invention is to provide a lane departure determination method capable of high-speed signal processing, minimizing the loss of lane information when the vehicle travels on a straight road. It is.

1 is a flowchart of a lane departure determining method according to the present invention;

FIG. 2 is a configuration diagram illustrating an image processing region setting step of FIG. 1. FIG.

3 is a configuration diagram illustrating an offset amount calculation step of FIG. 1.

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

CL: reference lane 10: circle

12: straight

In the lane departure determining method according to the present invention for achieving the technical problem, the distance between the center is equal to the width of the vehicle, the image processing area using the two circles set so that the center of each circle is present on the lane when driving in a straight line An image processing region setting step of setting a value; An outline detection step of detecting an outline in each processing region of the input image; A distribution survey step of examining the distribution of the contour line; A linear modeling step of modeling a lane in a straight line using pixels of a main distribution area; A determination step of determining whether the straight line exists in the processing area; A lane departure determining step of determining lane departure when the straight line does not exist in the processing area; An alarm or steering control step of outputting an alarm sound or automatically controlling steering upon lane departure; An offset amount calculation step of calculating an offset amount when the straight line exists in the processing area; And an offset amount comparing step of proceeding to the lane departure determining step if the offset amount is less than a reference value and proceeding to an outline detection step if the offset amount is a reference value or more.

According to a preferred feature of the present invention, the two circles preferably have a radius value in which the lane comes into contact with the circle when the vehicle leaves the lane.

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

1 is a flowchart illustrating a lane departure determining method according to the present invention, FIG. 2 is a block diagram showing an image processing area setting step of FIG. 1, and FIG. 3 is a step showing an offset amount calculation step of FIG. 1. The configuration diagram is shown.

As shown, the lane departure determination method of the present invention is largely the image processing region setting step (S100), the contour detection step (S110), the distribution diagram investigation step (S120), the linear modeling step (S130), and the straight line Determining whether the image exists in the image processing area (S140), offset amount calculation step (S150), offset amount comparison step (S160), lane departure determination step (S170), alarm or steering control step (S180) It is made, including.

In the image processing area setting step (S100), the distance between the centers (O) is equal to the width (W) of the vehicle, and the two fixed centers are set such that each center (O) is on the reference lane (RL: Reference Lane) when driving in a straight line. The image processing area is set using the circle 10, wherein the radius r of each circle 10 is a straight line 12 to be described below when the vehicle leaves the reference lane RL. Set to the value encountered.

In the present invention, setting the image processing area to two fixed circles 10 is effective because the circle 10 shows a larger area than the shapes of different shapes (for example, trapezoids) when the circumferential lengths are the same. This is because the processing area can be set, and in the case of the circle 10, since the distance r from the center O is constant, it is more efficient in the lane departure determining method than in the method using the trapezoidal processing area.

After setting the image processing area as described above, the process proceeds to the contour detection step (S110). In this step (S110), the photographing lens and the image pickup device are mounted on the front wheel side of the vehicle to photograph the subject, that is, the road on which the vehicle travels. A road image generated by a photographing unit (not shown) including a charge coupled device (CCD) is input to detect an outline of each image processing area.

Next, the process proceeds to the distribution survey step (S120) to investigate the distribution of the contour detected in each image processing area, and after examining the distribution map, the process proceeds to the linear modeling step (S130) to use pixels of the main distribution area. The lane is modeled by a straight line 12.

For example, when the straight line 12 is modeled as shown in FIG. 3 in the straight line modeling step S130, it is determined whether the straight line 12 exists in the image processing area set by the circle 10. At this time, if it is determined that the straight line 12 does not exist in the image processing area, the lane departure is determined (S170), and then an alarm sound is output or the steering system is automatically controlled to prevent lane departure ( S180).

When it is determined in step S140 that the straight line 12 exists in the image processing area, the process proceeds to an offset amount calculating step S150 to calculate the offset amount of the straight line 12. You can get it using the method.

In FIG. 3, the lengths of the line segments AC, line CE, and line segment AB can be easily obtained by modeling the straight line BC. By the way, since triangle ABC and triangle CDE are similar triangles, the following equation (1) holds between the line segment AC, the line segment CE, the line segment AB, and the line segment DE.

AC: CE = AB: DE ------------------------------------- Formula (1)

In the above formula (1), since the offset amount is a line segment DE, the offset amount can be easily obtained by using this formula (1).

As such, when the offset amount is less than the reference value in the offset amount calculation step S150, the process proceeds to the lane departure determining step S170 to determine lane departure, and then outputs an alarm sound or automatically controls the steering system to prevent lane departure. (S180).

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, in the lane departure determining method of the present invention, since the image processing area is fixed to two circles, the processing speed can be improved as compared with the method of changing the image processing area.

Also, by setting the circle having the largest area among the figures having the same circumference as the image processing region, the loss of lane information can be reduced relatively compared to other figures such as trapezoid, and the calculation of the offset amount for determining lane departure Compared with the conventional method, it is possible to implement a high speed lane departure prevention system.

Claims (2)

An image processing region setting step of setting an image processing region by using two circles in which the distance between the centers is equal to the width of the vehicle and the center of each circle is present on the lane when driving in a straight line; An outline detection step of detecting an outline in each processing region of the input image; A distribution survey step of examining the distribution of the contour line; A linear modeling step of modeling a lane in a straight line using pixels of a main distribution area; A determination step of determining whether the straight line exists in the processing area; A lane departure determining step of determining lane departure when the straight line does not exist in the processing area; An alarm or steering control step of outputting an alarm sound or automatically controlling steering upon lane departure; An offset amount calculation step of calculating an offset amount when the straight line exists in the processing area; An offset amount comparison step of proceeding to the lane departure determining step if the offset amount is less than a reference value and proceeding to an outline detection step if the offset amount is a reference value or more; Lane departure determination method comprising a. 2. The lane departure determining method according to claim 1, wherein the two circles are set to have a radius value in which the lane comes into contact with the circle when the vehicle leaves the lane.