JP5814757B2 - Lane departure detection device - Google Patents

Description

  The present invention relates to a lane departure detection apparatus. More specifically, the present invention relates to a lane departure detection device that detects a traveling state of a vehicle based on a vehicle front image captured by an imaging unit such as an on-vehicle camera and prevents the vehicle from deviating from the traveling lane.

  If the vehicle meanders or the vehicle deviates from the driving lane due to driver's carelessness or falling asleep, there is a high possibility of causing an accident. In particular, when the vehicle deviates from the driving lane and jumps to the opposite lane or enters the sidewalk, there is a high possibility of causing a serious accident. In order to prevent such an accident, it is very important to detect whether the vehicle is traveling in the traveling lane and whether the vehicle is traveling along the traveling lane.

As a method for detecting whether the vehicle is traveling in the traveling lane and whether the vehicle is traveling along the traveling lane (hereinafter collectively referred to as the traveling state of the vehicle), there is a technique using an image. Many have been developed (for example, Patent Documents 1 to 6).
Such a technique has a camera and other imaging means mounted on the vehicle, and detects the vehicle on which the camera is mounted and a marking line (center line, side line, etc.) from the vehicle front image captured by the imaging means. The relative position between the vehicle and the marking line is calculated to determine the running state of the vehicle.

  For example, Patent Documents 1 to 4 disclose techniques for calculating a distance between a marking line and a vehicle based on an image and determining a traveling state of the vehicle based on the distance. For example, a technology is disclosed that issues a warning to the driver by determining that there is a possibility of deviating from the traveling lane when the distance from the reference position of the vehicle to the marking line is equal to or less than a certain distance.

  Further, Patent Documents 5 and 6 disclose techniques for detecting a marking line based on an image, obtaining a vehicle attitude with respect to the detected marking line, and determining a traveling state of the vehicle based on the vehicle attitude. ing. For example, a technique for determining the possibility of deviating from the traveling lane based on the difference between the traveling direction of the vehicle and the inclination of the marking line is disclosed.

However, the conventional technology detects the marking line from the photographed vehicle forward image and extracts the entire image of the marking line, and then the distance between the marking line and the vehicle, or the direction of the vehicle with respect to the direction in which the marking line extends, etc. Therefore, it takes time to determine the traveling state of the vehicle.
In particular, when extracting the entire image of the marking line, it is necessary not to misidentify other vehicles existing on the roadway or objects existing on the side of the roadway, such as utility poles or guardrails, as marking lines. There is a problem that it takes time to perform image processing to prevent such misidentification.

JP 2001-341599 A JP 2010-167932 A JP 2010-173367 A WO2008 / 114382 gazette JP-A-6-162398 JP 2002-211428 A

  In view of the above circumstances, an object of the present invention is to provide a lane departure detection device that can appropriately determine the traveling state of a vehicle in a short time.

A lane departure detection device according to a first aspect of the present invention is an imaging means mounted on a vehicle for taking an image of the front of the vehicle, and a running state detecting means for detecting the running state of the vehicle based on an image taken by the taking means. The photographing means is arranged so that the front end portion of the vehicle and the roadway on which the vehicle travels are photographed in the same image, and the traveling state detecting means is provided by the photographing means. In the photographed image, a detection area setting unit that sets a strip area parallel to the roadway immediately before the front end of the vehicle as a detection area, and a marking line that divides a driving lane located in the detection area are detected. A marking line detection unit; and a traveling determination unit that sets a plurality of determination regions in the detection region and determines a traveling state of the vehicle based on a relative position of the plurality of determination regions and the marking line. in which, the The exit area setting unit is configured such that, in the image captured by the imaging unit, the height of the detection area is shorter than the length of the marking line in the direction along the traveling direction of the vehicle in the image, and the vehicle travels. Even if the lane to be curved is curved, the detection area is set so that the marking line has a length that can be regarded as a substantially straight line in the detection area .
A lane departure detection device according to a second aspect of the present invention is an imaging unit mounted on a vehicle for imaging the front of the vehicle, and a traveling state detection unit for detecting a traveling state of the vehicle based on an image captured by the imaging unit. The photographing means is arranged so that the front end portion of the vehicle and the roadway on which the vehicle travels are photographed in the same image, and the traveling state detecting means is provided by the photographing means. In the photographed image, a detection area setting unit that sets a strip area parallel to the roadway immediately before the front end of the vehicle as a detection area, and a marking line that divides a driving lane located in the detection area are detected. A marking line detection unit; and a traveling determination unit that sets a plurality of determination regions in the detection region and determines a traveling state of the vehicle based on a relative position of the plurality of determination regions and the marking line. And said The exit area setting unit is configured such that, in the image photographed by the photographing means, the height of the detection area is shorter than the length of the marking line in the direction along the traveling direction of the vehicle in the image. The detection area is set such that the height is substantially the same as the width of the marking line located inside .
In the lane departure detection device according to a third aspect of the present invention, in the first or second aspect, the travel judgment unit compares a plurality of images taken at different timings, and the change in the judgment area where the marking line exists. It has the function to judge the running state of a vehicle based on this.
In the lane departure detection device according to a fourth aspect of the present invention, in the first, second, or third aspect, the detection area setting unit is disposed in the detection area at a position that is bilaterally symmetrical with respect to a center in the vehicle width direction of the vehicle. A pair of stable traveling areas are formed, and the pair of stable traveling areas is configured such that the vehicle has the traveling lane in which the marking lines are marked on both sides of the traveling lane and the vehicle has a central axis thereof. In the state where the vehicle travels so as to coincide with the central axis of the travel lane, both the pair of marking lines are set so as to be positioned within the pair of stable travel regions.

According to the first aspect of the present invention, only the marking line in the strip-shaped detection area set by the detection area setting unit is detected, and the traveling determination unit sets a plurality of determination areas in the detection area to determine which determination area. It is only determined whether or not there is a marking line. Therefore, since the process for detecting the marking line and the determination process of the traveling state can be performed in a short time, the traveling state of the vehicle can be determined in a short time. In addition, since the area immediately before the front end of the vehicle is set as the detection area, it is possible to reduce the possibility that something other than the marking line existing in the area exists in the detection area. Therefore, the detection error of the marking line can be reduced, so that the running state of the vehicle can be detected with high accuracy. Moreover, since the height of the detection area is shorter than the length of the marking line, it is easy to detect the marking line by the marking line detection unit, so the processing for detecting the marking line is performed in a short time. be able to. Further, the height of the detection area is set so that the marking line can be regarded as a substantially straight line in the detection area even if the lane is curved. Then, when there is a marking line in the detection area, the range of the width that the marking line area can take can be reduced, so that the detection of the marking line is facilitated in the marking line detection unit, and the detection accuracy is also increased. be able to.
According to the second aspect of the present invention, only the marking line in the strip-shaped detection area set by the detection area setting section is detected, and the traveling determination section sets a plurality of determination areas as the detection areas to determine which determination area. It is only determined whether or not there is a marking line. Therefore, since the process for detecting the marking line and the determination process of the traveling state can be performed in a short time, the traveling state of the vehicle can be determined in a short time. In addition, since the area immediately before the front end of the vehicle is set as the detection area, it is possible to reduce the possibility that something other than the marking line existing in the area exists in the detection area. Therefore, the detection error of the marking line can be reduced, so that the running state of the vehicle can be detected with high accuracy. Moreover, since the height of the detection area is shorter than the length of the marking line, it is easy to detect the marking line by the marking line detection unit, so the processing for detecting the marking line is performed in a short time. be able to. Furthermore, the height of the detection area is set to be substantially the same as the width of the marking line located inside the detection area. Then, when there is a marking line in the detection area, the range of the width that the marking line area can take can be reduced, so that the detection of the marking line is facilitated in the marking line detection unit, and the detection accuracy is also increased. be able to.
According to the third aspect of the present invention, it is possible to determine the movement state of the vehicle along the width direction of the travel lane, so that the travel state of the vehicle can be detected more accurately.
According to the fourth aspect of the present invention, the movement of the vehicle in the width direction of the traveling lane relative to the center of the traveling lane can be accurately detected on the road where the marking lines are marked on both sides of the traveling lane.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing of the lane departure detection apparatus 1 of this embodiment, (A) is the figure explaining the mounting condition to the vehicle A, (B) is a block diagram of the lane departure detection apparatus 1. FIG. (A) is a schematic explanatory diagram of an image P photographed by the photographing means 10, (B) is a schematic explanatory diagram of an inspection area image DA1 cut out from the image P, and (C) is a photograph of a marking line LM. FIG. 5 is a schematic explanatory diagram of an inspection area image DA1 that is being displayed.

Next, an embodiment of the present invention will be described with reference to the drawings.
The lane departure detection apparatus according to the present invention detects a traveling state of a vehicle, specifically, whether or not the vehicle is likely to deviate from the traveling lane based on an image captured by an imaging unit mounted on the vehicle. It is a device that detects the possibility that the vehicle deviates from the traveling lane based on the relative positional relationship between the marking line marked on the roadway and the vehicle.
In the present specification, the marking line is a line that divides the traveling lane on the roadway. For example, a center line or a side line (roadway outer line) corresponds to the marking line, and the color of the line (whether white or yellow) or the form of the line (continuous line or broken line) is not particularly limited.

(Description of the lane departure detection device 1 of the present embodiment)
As shown in FIG. 1, the lane departure detection device 1 according to this embodiment includes an imaging unit 10 and a traveling state detection unit 20 and is mounted on a vehicle A that is a target for detecting a lane departure. Yes.

(Photographing means 10)
As shown in FIG. 1, the photographing means 10 is capable of photographing an image of a CCD camera or the like and transmitting image data (image data, photographing timing, etc.) photographed to the outside. The photographing means 10 is disposed at a position where the situation of the roadway R in front of the vehicle A can be photographed. For example, the vehicle can be disposed in the vicinity of the rearview mirror so that the roadway R in front of the vehicle A can be measured through the front window of the vehicle. The position where the photographing means 10 is disposed in A is not particularly limited.

As shown in FIG. 1, the photographing means 10 is arranged so that at least both the road surface of the roadway R and the front end portion of the vehicle A are photographed in the same image P (see FIG. 2A). ). For example, as shown in FIG. 1A, when the parallel line parallel to the roadway R is HL, the photographing means 10 is arranged so that its optical axis CA is inclined downward with respect to the parallel line HL. In addition, if the parallel line HL and the front end of the vehicle A are positioned within the angle of view VA, both can be photographed in the same image P.
Further, the photographing means 10 is arranged so that the lateral direction of the image P to be photographed is parallel to the road R when the vehicle A is arranged on the flat road R. The reason will be described later.

(Running state detection means 20)
The traveling state detection unit 20 has a function of detecting the traveling state of the vehicle A based on the image P photographed by the photographing unit 10. The traveling state detection unit 20 includes an inspection area setting unit 21, a marking line detection unit 22, a traveling determination unit 23, and a storage unit 25.

The traveling state detection means 20 is a control device such as a computer, for example, and can execute the following functions of the inspection area setting unit 21, the marking line detection unit 22, and the traveling determination unit 23. In addition, the storage unit 25 can store, for example, an image P such as a hard disk or a memory, an inspection area image DA1 described later, and marking line information.
Further, the traveling state detection unit 20 may have a control function for controlling the operation of the photographing unit 10 (for example, timing for photographing the image P).

(Inspection area setting unit 21)
The inspection area setting unit 21 has a function of receiving the data of the image P transmitted from the imaging means 10 and setting an area (detection area DA) for detecting the marking line LM based on the data of the image P. It is. The detection area DA set by the inspection area setting unit 21 is a horizontally long strip-shaped area parallel to the roadway R located immediately before the front end of the vehicle A in the image P.
The inspection area setting unit 21 has a function of cutting out an image in the detection area DA from the image P to obtain an inspection area image DA1 (see FIG. 2C). That is, it has a function of cutting out a part of the image P as a horizontally long strip-shaped image.
In addition, the inspection area setting unit 21 has a function of transmitting the inspection area image DA1 to the marking line detection unit 22 and the storage unit 25 together with the image data transmitted from the imaging unit 10.

(Setting of detection area DA)
The above-described detection area DA is set at a specific position of the image P by the inspection area setting unit 21. That is, in any image P, the detection area DA is set at the same position.
For example, in the setting image P that is taken in a state where the vehicle A is arranged on the flat road R, it is a horizontally long strip and is parallel to the road R at a position away from the front end of the vehicle A by a predetermined distance. A designated area is set, and the position of this designated area (for example, the coordinates of the four corners of the area) is stored in the inspection area setting unit 21. Then, in any image P, the detection area DA can be set at the same position as the designated area.

  The width of the detection area DA to be set (in the left-right direction in FIG. 2) is not particularly limited. For example, the detection area DA can be set so that the width thereof is substantially the same as the width of the front end portion of the vehicle A photographed in the setting image P. Further, the width of the detection area DA may be set based on the actual width of the front end portion of the vehicle A.

  Although the height of the detection area DA to be set is not particularly limited, it is shorter than the length of the marking line LM and is long enough to allow the marking line LM to be regarded as a substantially straight line in the detection area DA even if the lane R is curved. It is preferable. For example, in the detection area DA in the setting image P, if the width of the marking line LM is photographed to about 150 to 200 mm, the detection area DA can be obtained by setting the height of the detection area DA to about 150 to 200 mm. In the figure, the marking line LM is almost linear. That is, the detection area DA is made to be substantially the same height as the width of the marking line LM located inside the detection area DA. Then, it is easy to detect the marking line LM in the marking line detection unit 22, and the detection accuracy can be increased. This is because when the marking line LM exists in the detection area DA, the range of the width that the area of the marking line LM can take can be reduced.

The inspection area setting unit 21 may set the detection area DA for each image P based on each captured image P. In this case, even if the roadway R is inclined, the detection area DA can be set appropriately.
For example, a direction parallel to the front end of the vehicle A and the surface of the road R is obtained from the image P, and the axial direction is parallel to the surface of the road R at a position away from the front end of the vehicle A by a predetermined distance. The detection area DA may be set. In this case, the width and height of the detection area DA may be predetermined lengths, but may be changed for each image P according to the behavior of the vehicle A. For example, the width of the detection area DA is set to be approximately the same as the width of the front end portion of the vehicle A obtained from the image P, or the height of the detection area DA is changed from a predetermined height to the inclination of the vehicle. You may make it change according to it.

(Signal line detection unit 22)
The marking line detection unit 22 has a function of receiving the data of the inspection area image DA1 transmitted from the inspection area setting unit 21 and detecting the marking line LM from the data of the inspection area image DA1.
Further, the marking line detection unit 22 determines the position of the detected marking line LM in the inspection area image DA1, specifically, how far away from the center CL of the inspection area image DA1 the marking line LM exists. And a function of transmitting information related to the position of the marking line LM (such as a distance from the center CL to the marking line LM) to the travel determination unit 23 and the storage unit 25.

The marking line detection unit 22 detects the marking line LM by the following method.
First, since the marking line LM is usually photographed with higher luminance than the road surface of the roadway R, a portion with high luminance in the inspection area image DA1 is set as an area having a high possibility of being the marking line LM.
Next, as shown in FIG. 2C, with respect to the area determined to be highly likely to be the marking line LM, it is determined whether or not the area is a continuous area from the upper end to the lower end of the inspection area image DA1. To do. And the width | variety is calculated about the area | region judged to be continuous from an upper end to a lower end, and the area | region where the width | variety is in a predetermined range is judged to be the marking line LM.
If such a method is adopted, an area having a luminance of a predetermined value or more is detected in the inspection area image DA1, and whether or not the area is continuous from the upper end to the lower end, and the width is within the predetermined range. Therefore, it is possible to detect the marking line LM by a quick and simple process.

Then, when a certain area is determined to be the marking line LM, the marking line detection unit 22 calculates a distance from the area to the center CL of the inspection area image DA1. For example, in the inspection area image DA1, the distance ML from the position closest to the center CL to the center CL is calculated, and information regarding this distance is transmitted to the travel determination unit 23 and the storage unit 25.
Below, the information regarding the distance from the area determined as the marking line LM to the center CL of the inspection area image DA1 is referred to as marking line information.

  In the above example, a portion having a high luminance in the inspection area image DA1 is determined as an area having a high possibility of being the marking line LM. However, an area having a high possibility of being the marking line LM from the inspection area image DA1 is determined. The extraction method is not particularly limited. For example, when the photographing unit 10 that can shoot a color image is adopted, an area that is the color of the marking line LM (for example, white or yellow) is an area that is likely to be the marking line LM. You may make it judge.

  Further, the width of the area determined to be the marking line LM can be set based on the width W of the marking line LM photographed in the setting image P. For example, the central axis of the vehicle A and the central axis of the traveling lane TL are located on a flat road R having an average width (for example, about 3.5 m) of the traveling lane TL in the same plane orthogonal to the road R. Thus, the vehicle A is arranged. Then, it can be set to about ± 50% with respect to the width of the marking line LM in the designated area obtained in the setting image P photographed in that state.

(Running judgment unit 23)
The traveling determination unit 23 has a marking line position detection function that sets a plurality of determination areas in the inspection area image DA1 and determines in which determination area the marking line LM detected by the marking line detection unit 22 exists. Have.
The traveling determination unit 23 has a traveling determination function for determining the traveling state of the vehicle A based on the area where the marking line LM detected by the marking line position detection function exists.
The traveling determination unit 23 is connected to an alarm unit 30 that issues a warning to the driver, and has a function of transmitting a signal that activates the alarm unit 30 according to the traveling state of the vehicle A. For example, when the warning means 30 receives a signal from the traveling determination unit 23, an apparatus having a function of sounding a buzzer or blinking an indicator can be employed.

(Marking line position detection function)
The traveling determination unit 23 has a function of setting a plurality of determination areas in the inspection area image DA1. Specifically, a plurality of determination areas JA are set so that the inspection area image DA1 is a line contrast across the center CL. As the determination area JA, the following three areas are set on one side across the center CL of the inspection area image DA1.
First, in a situation where the vehicle A is moving along the center of the travel lane TL, the stable travel area SA is set in an area where the marking line LM is considered to be located. The stable travel area SA is set to a predetermined width. For example, the width of the stable travel area SA is within ± 0.5 m from the center of the travel lane TL. Even if the vehicle A moves in the width direction of the travel lane TL, the entire marking line LM is within the stable travel area SA. Is set to be located at In this case, when the marking line LM exists on both sides of the travel lane TL, the vehicle A moves in the width direction of the travel lane TL within the above range in a situation where the vehicle A is moving along the center of the travel lane TL. It is preferable to set the stable travel region SA so that both the marking lines LM are located within the stable travel region SA even if the vehicle moves.

  A dangerous area BA is set between the stable running area SA and the center CL of the inspection area image DA1, and an outer area OA is set outside the stable running area SA. The reason why the outer area OA is provided is to more reliably detect that the vehicle A protrudes from the road R to the left and right (in other words, on the sidewalk side or on the opposite lane). For example, when the driving lane TL enters the outer area OA, the warning means 30 described later informs the driver that the driving lane TL is in a more dangerous situation than the state where the driving lane TL enters the danger area BA. Therefore, safety can be further improved.

  The travel determination unit 23 has a function of determining in which area of the determination area JA the area assumed to be the marking line LM is based on the marking line information transmitted from the marking line detection unit 22. Yes. Specifically, the distance SL between the stable traveling area SA and the center CL of the inspection area image DA1 is compared with the distance ML included in the marking line LM information. When the distance SL ≧ the distance ML, the marking line LM is compared. Is determined to belong to the stable traveling area SA, and if the distance SL <distance ML, the marking line LM is determined to belong to the dangerous area BA.

(Run judgment function)
When it is detected which region the marking line LM belongs to, the traveling determination unit 23 determines the traveling state of the vehicle A based on the region to which the marking line LM belongs. Specifically, when the marking line LM belongs to the stable traveling area SA, it is determined that the vehicle A is traveling safely. In this case, the travel determination unit 23 does not send a signal to the alarm means 30.
On the other hand, when the marking line LM belongs to the danger area BA, it is determined that the vehicle A is approaching one of the marking lines LM, and there is a possibility that the vehicle will stick out to the oncoming lane or enter the sidewalk. In this case, the travel determination unit 23 transmits a signal to the alarm means 30.

  Since the lane departure detection device 1 of the present embodiment is configured as described above, the traveling state of the vehicle A can be detected by the traveling state detection unit 20 based on the image P photographed by the photographing unit 10. Therefore, when the traveling state of the vehicle A becomes a dangerous state, the warning means 30 can inform the driver that the vehicle is in a dangerous state.

Further, in the lane departure detection device 1 according to the present embodiment, whether or not the marking line LM exists in the strip-shaped detection area DA set by the detection area setting unit 21 as the marking line LM serving as a reference for the traveling state determination. I'm just investigating. Moreover, whether or not it is the marking line LM can be determined only by the width of the area considered to be the marking line LM and whether or not the area is continuous from the upper end to the lower end of the detection area DA. Can be easily executed in a short time.
The traveling determination unit 23 only determines the traveling state of the vehicle A depending on which region of the determination area JA the marking line LM is located on, so that the process for determining the traveling state of the vehicle A is also performed in a short time. Can be done with

  Furthermore, since the horizontally long strip-shaped area immediately before the front end of the vehicle A in the image P is set as the detection area DA, the possibility that something other than the marking line LM exists in the detection area DA itself can be reduced. Therefore, since the detection mistake of the marking line LM can be reduced, the accuracy of determining the traveling state of the vehicle A can be increased.

  In the above example, a case has been described in which each area of the determination area JA is set as a contrast with respect to the center CL of the inspection area image DA1 (that is, the center of the detection area DA). The area is not necessarily set in this way. For example, each area of the determination area JA is set only from the center CL of the inspection area image DA1 to the center line side of the marking line LM, or from the center CL of the inspection area image DA1 to only the side line side of the marking line LM. Also good. Even in this case, if it is detected to which region the center line and the side line belong, it can be determined whether or not the traveling state of the vehicle A is a dangerous state.

(Setting of judgment area)
The determination area may be set based on the setting image P when the detection area DA is set based on the setting image P.
When the inspection area setting unit 21 sets the detection area DA based on each captured image P, each determination area is set with a specific image (for example, the setting image P). Each determination area can be set in the set detection area DA according to the relative ratio at the time.

(Other examples of running judgment)
In the above example, the case where the traveling state of the vehicle A is determined based only on the image P taken at a certain timing has been described. However, in detecting that the meandering of the vehicle A or the traveling direction of the vehicle A has suddenly changed, It is preferable to continuously grasp the behavior of the vehicle A.
Therefore, for a plurality of images P taken at different timings, the traveling state of the vehicle A may be determined based on the information of the area to which the marking line LM obtained from each image P belongs.

  For example, at a certain timing, the marking line LM belongs to the stable traveling area SA, but after a predetermined time has elapsed, the marking line LM belongs to the dangerous area BA, and then the marking line LM belongs to the stable traveling area SA again. In such a case, it is estimated that the vehicle A meanders. If such a meandering operation occurs, the driver may be asleep. Therefore, if the alarm device 30 is activated to make a sound that wakes the driver, the accident will occur in advance. Can be prevented.

  Further, at a certain timing, the marking line LM belongs to the stable travel area SA, but after a predetermined time has elapsed, the vehicle A travels if it belongs to the risk area BA and is located in the risk area BA as it is. There is a possibility that the vehicle is traveling with an inclination to the lane TL. In such a case, since the driver may be looking aside, if the alarm device 30 is activated to emit a light or sound that alerts the driver, an accident may occur beforehand. Can be prevented.

Furthermore, when the information on the distance ML from the marking line LM to the center CL of the inspection area image DA1 is included in the information of the area to which the marking line LM belongs, based on the distance ML obtained from the continuous images P. The fluctuation speed of the distance ML may be calculated. In this case, there is a possibility that a driving error has occurred. Therefore, if the alarm device 30 is activated to emit a light or sound that alerts the driver, an accident can be prevented in advance. .
If the fluctuation speed of the distance ML can be grasped, the timing at which the marking line LM enters the danger area BA from the stable travel area SA can be estimated from the fluctuation speed. Therefore, when the fluctuation speed of the distance ML can be grasped, a warning by the warning device 30 is issued before the time when the marking line LM is estimated to enter the dangerous area BA from the stable traveling area SA (for example, 0.5 seconds before). If it is done, safety can be further improved.

  The lane departure detection device of the present invention is mounted on a vehicle and is suitable as a device for detecting meandering of a vehicle, traveling lane departure, and the like.

DESCRIPTION OF SYMBOLS 1 Lane departure detection apparatus 10 Imaging | photography means 20 Traveling state detection means 21 Detection area setting part 22 Marking line detection part 23 Traveling determination part DA detection area JA Judgment area SA Stable driving area BA Risk area LM Marking line A Vehicle P Image R Roadway

Claims (4)

Photographing means mounted on the vehicle for photographing the front of the vehicle;
Traveling state detection means for detecting the traveling state of the vehicle based on an image photographed by the photographing means,
The photographing means includes
The front end portion of the vehicle and the roadway on which the vehicle travels are arranged so as to be photographed in the same image,
The running state detecting means includes
In the image photographed by the photographing means, a detection area setting unit that sets a strip area parallel to the roadway just before the front end of the vehicle as a detection area;
A marking line detection unit that detects a marking line that divides the traveling lane, located in the detection area;
A plurality of determination areas are set in the detection area, and a traveling determination unit that determines the traveling state of the vehicle based on the relative positions of the plurality of determination areas and the marking line ,
The detection area setting unit includes:
In the image photographed by the photographing means, the height of the detection area is shorter than the length of the marking line in the direction along the traveling direction of the vehicle in the image, and the lane in which the vehicle travels is curved. However , the lane departure detection device is characterized in that the detection area is set so that the marking line has a length that can be regarded as a substantially straight line in the detection area . Photographing means mounted on the vehicle for photographing the front of the vehicle;
Traveling state detection means for detecting the traveling state of the vehicle based on an image photographed by the photographing means,
The photographing means includes
The front end portion of the vehicle and the roadway on which the vehicle travels are arranged so as to be photographed in the same image,
The running state detecting means includes
In the image photographed by the photographing means, a detection area setting unit that sets a strip area parallel to the roadway just before the front end of the vehicle as a detection area;
A marking line detection unit that detects a marking line that divides the traveling lane, located in the detection area;
A plurality of determination areas are set in the detection area, and a traveling determination unit that determines the traveling state of the vehicle based on the relative positions of the plurality of determination areas and the marking line,
The detection area setting unit includes:
In the image photographed by the photographing means, the height of the detection area is shorter than the length of the marking line in the direction along the traveling direction of the vehicle in the image, and the height of the detection area is inside the image. The lane departure detection apparatus according to claim 1, wherein the detection area is set so as to be substantially the same as a width of the mark line that is positioned . The travel determination unit
2. A function of comparing a plurality of images taken at different timings and determining a running state of a vehicle based on a change in the determination area where the marking line exists. The lane departure detection device according to 2. The detection area setting unit includes:
In the detection area, a pair of stable travel areas arranged at positions symmetrical to the center of the vehicle in the vehicle width direction are formed.
The pair of stable running areas is
In a state where the vehicle is traveling on the traveling lane in which the marking line is marked on both sides of the traveling lane so that the center axis thereof coincides with the central axis of the traveling lane, the pair of marking lines is The lane departure detection device according to claim 1, 2 or 3, wherein both are set so as to be located in the pair of stable running areas.