JP5772571B2 - Lane guidance display system, method and program - Google Patents

Description

  The present invention relates to a lane guidance display system, method, and program for displaying guidance of recommended lanes that a vehicle should travel.

  2. Description of the Related Art Conventionally, a technique is known in which an arrow indicating a recommended lane image that a vehicle should travel is superimposed and displayed on a front image obtained by photographing the front of the vehicle (see Patent Document 1, Second Embodiment). ). In Patent Document 1, the driver can recognize the recommended lane in which the vehicle is to travel by superimposing an arrow on the image of the recommended lane in the front image.

JP 2008-151752 A

However, when there is another lane between the travel lane in which the vehicle is currently traveling and the recommended lane, there is a problem that the driver misrecognizes that the other lane is the recommended lane. Here, misrecognizing that another lane existing between the travel lane and the recommended lane is the recommended lane means that the number of lanes to be changed is erroneously recognized less than the original. If the number of lanes to be changed is erroneously recognized less than the original number, a situation may occur in which the vehicle cannot be guided to the true recommended lane.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a technology that can reliably guide a vehicle to a recommended lane even when another lane exists between the travel lane and the recommended lane.

  In order to achieve the above object, in the present invention, the front image acquisition means acquires a front image obtained by photographing the front of the vehicle. The lane specifying means specifies, in the front image, an image of a recommended lane that the vehicle should change from the traveling lane in which the vehicle is currently traveling. The display control unit causes the display unit to display a front image in which a guide line including a recommended lane side guide line portion indicating a recommended lane image in the front image is superimposed. Further, the display control means changes the superimposed position of the recommended lane side guide line portion in the horizontal direction of the image of the recommended lane according to whether or not another lane exists between the travel lane and the recommended lane. Hereinafter, other lanes existing between the travel lane and the recommended lane are referred to as intervening lanes.

  When there is an intervening lane, a misrecognition that the intervening lane is a recommended lane may occur. Therefore, the number of lanes to be changed can be erroneously recognized less than the original. On the other hand, when there is no intervening lane, it is natural that an erroneous recognition that the intervening lane is a recommended lane cannot occur, and the number of lanes to be changed cannot be erroneously recognized. Therefore, in the above configuration, the number of lanes to be changed is originally changed by changing the overlapping position of the recommended lane side guide line portion in the horizontal direction of the recommended lane image depending on whether or not there is an intervening lane. The superimposition position of the recommended lane side guide line portion can be set so as to prevent the erroneous recognition according to the possibility of erroneous recognition. Therefore, even when there is an intervening lane, the vehicle can be reliably guided to the recommended lane.

  The forward image acquisition means only needs to acquire a forward image obtained by photographing the front of the vehicle. For example, the forward image may be acquired from a camera including the front of the vehicle in the field of view. The front of the vehicle means the front of the vehicle in the traveling direction. In particular, when written as the front side in a certain lane, it means the front side of the traveling direction (lane direction) of the vehicle in the lane. The position in the lane direction appears in the vertical position in the front image displayed on the display unit. On the other hand, the position in the width direction in the lane appears in the position in the horizontal direction in the front image displayed on the display unit.

  The lane identification unit may identify the recommended lane image in the front image, and may identify the recommended lane image by recognizing the image characteristics of the recommended lane image in the front image. For example, the lane specifying means may specify the recommended lane image by recognizing the image of the recommended lane markings by a known line recognition method such as Hough transform. Further, the lane specifying means may acquire the position of the recommended lane from the map information and specify the image of the recommended lane in the front image based on the acquired position. The recommended lane is a lane that should be changed from the traveling lane to a lane that is different from the traveling lane. The lane specifying means may use, as a recommended lane image, an image of a lane that can reach the destination point on a planned travel route searched in advance. Further, the lane specifying means, when there is a lane to be traveled when entering the intersection ahead of the vehicle in the planned travel route, displays the image of the lane at the stage of approaching the intersection within a predetermined distance. It may be specified as an image. The lane specifying means may specify an image of a lane that can travel safely or more smoothly than a travel lane as a recommended lane image on a road on which the vehicle is traveling.

  The display control means need only change the superimposition position of the recommended lane side guide line portion in the horizontal direction of the recommended lane image, and superimposes so that a part or all of the recommended lane side guide line portion translates in the horizontal direction. The position may be changed. Further, the display control means may change the superimposed position so that a part or all of the recommended lane side guide line part is moved in the horizontal direction by rotational movement. The display control means may maintain the length of the recommended lane side guide line portion at a predetermined value or more. Thereby, the recommended lane side guide line portion can be surely visually recognized in the front image, and the image of the recommended lane indicated by the recommended lane side guide line portion can be easily recognized. Further, the recommended lane side guide line portion can take various line shapes. Further, the recommended lane side guide line portion is not limited to a continuous line but may be a broken line or a chain line. Furthermore, the recommended lane side guide line portion is not limited to a thin line, and may be a figure such as an arrow.

  Further, the display control means may set the position of the center in the horizontal direction in the recommended lane image as the superimposed position of the recommended lane side guide line portion when there are N or more intervening lanes (N is a natural number). Here, when there are no N or more intervening lanes, it can be said that the traveling lane and the recommended lane are close to each other to some extent, and the image of the recommended lane appears large in the front image. The larger the recommended lane image appears in the front image, the lower the possibility of erroneous recognition of the recommended lane image indicated by the recommended lane side guide line portion. In this way, when the possibility of misrecognizing the recommended lane image is low, if the center position in the horizontal direction in the recommended lane image is set as the superimposed position of the recommended lane side guide line part, the intervening lane becomes the recommended lane. Thus, the driver can be made aware that the vehicle should travel in the center position in the width direction in the recommended lane.

  On the other hand, when there are N or more intervening lanes, the traveling lane and the recommended lane are somewhat distant from each other, and the recommended lane image appears small in the front image. The smaller the recommended lane image appears in the front image, the higher the possibility of erroneous recognition of the recommended lane image indicated by the recommended lane side guide line portion. In this way, when the possibility of misrecognizing the recommended lane image is high, the position of the recommended lane side guide line is corrected from the center position in the horizontal direction in the recommended lane image to the opposite side of the traveling lane image. If it is set as the superimposing position, it can be prevented that the intervening lane is erroneously recognized as the recommended lane. Accordingly, it is possible to prevent erroneous recognition of the number of lanes to be changed to be less than the original, and the vehicle can be reliably guided to the recommended lane. In this case, the number of lanes to be changed may be misrecognized more than originally, but the problem is that the driver can recognize the true recommended lane as the lane change progresses and approaches the recommended lane. It will not be. As the vehicle moves closer to the recommended lane as the lane change progresses, the recommended lane image becomes larger in the front image, and the positional relationship between the recommended lane image and the recommended lane side guide line portion is also clarified. Because it goes. Also, if the number of lanes to be changed is misrecognized more than originally, the start of the lane change may be earlier than the original, but the start of the lane change will not be delayed, so the lane change is completed. The vehicle will not be able to be guided to the recommended lane before the necessary point (for example, an intersection or a branch point).

  However, if the number of intervening lanes is N or more, but the number is less than M (M is a natural number greater than N), the display control means travels from the center position in the horizontal direction in the recommended lane image as an exception. A position corrected to the image side of the lane may be set as a superimposition position of the recommended lane side guide line portion. In this way, the position corrected from the horizontal center position in the recommended lane image to the image side of the driving lane is set as the overlapping position of the recommended lane side guide line portion, so that the opposite side of the driving lane with respect to the recommended lane Therefore, it is possible to prevent the driver from erroneously recognizing that the adjacent lane is the recommended lane. Here, when there are fewer than M intervening lanes, the intervening lanes adjacent to the recommended lane are close to the driving lane to some extent, and the driver clearly recognizes the image of the intervening lane adjacent to the recommended lane in the front image. Can do. Accordingly, when there are fewer than M intervening lanes, the recommended lane is also superposed on the recommended lane-side guide line portion at the position corrected from the horizontal center position in the recommended lane image to the image side of the traveling lane. The driver can clearly recognize that the side guide line portion does not indicate an intervening lane adjacent to the recommended lane. For example, if there are fewer than two intervening lanes (when the intervening lane is only one lane adjacent to the driving lane), the driver clearly indicates that the recommended lane side guide line portion does not point to the intervening lane image. Can be recognized. Accordingly, when the number of intervening lanes is smaller than M, the position corrected from the lateral center position in the recommended lane image to the image side of the traveling lane is set as the superimposed position of the recommended lane side guide line portion. The recommended lane can be accurately recognized.

  However, even if there are fewer than M intervening lanes, if there is no lane adjacent to the recommended lane from the opposite side of the driving lane, an adjacent lane is recommended from the opposite side of the driving lane to the recommended lane. There is no possibility that the driver will misunderstand that it is a lane. Therefore, even when the number of intervening lanes is less than M, the display control means, when there is no lane adjacent to the recommended lane from the opposite side of the traveling lane, A position corrected from the position to the opposite side of the image of the traveling lane may be set as the superimposed position of the recommended lane side guide line portion.

  Furthermore, the method of guiding the image of the recommended lane by the guide line superimposed on the front image as in the present invention can also be applied as a program or method. In addition, the above lane guidance display system, program, and method may be realized as a single device or may be realized by using parts shared with each part provided in the vehicle. Including embodiments. That is, each means constituting the lane guidance display system may be distributed and provided in a plurality of substantial devices. When each means is distributed and provided in a plurality of substantive devices, a communication means for transmitting and receiving data necessary to make each means function may be provided. Furthermore, it is possible to provide a navigation apparatus, method, and program that include at least a part of the lane guidance display system as described above. Further, some changes may be made as appropriate, such as a part of software and a part of hardware. Furthermore, the present invention can be realized as a recording medium for a program for controlling the lane guidance display system. Of course, the software recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium to be developed in the future.

It is a block diagram of a navigation apparatus. (2A) to (2D) are plan views of the road. (3A) and (3B) are diagrams showing a front image, and (3C) is a diagram for explaining a superimposed position of a recommended lane side guide line portion. (4A) to (4D) are diagrams (partially enlarged view) showing a front image. It is a flowchart of a lane guidance display process.

Here, embodiments of the present invention will be described in the following order.
(1) Configuration of navigation device:
(2) Lane guidance display processing:
(3) Other embodiments:

(1) Configuration of navigation device:
FIG. 1 is a block diagram showing a configuration of a navigation device 10 as a lane guidance display system according to an embodiment of the present invention. The navigation device 10 is provided in the vehicle C. The navigation device 10 includes a control unit 20 and a recording medium 30. The control unit 20 includes a CPU, a RAM, a ROM, and the like, and executes a program stored in the recording medium 30 or the ROM. The recording medium 30 records map information 30a. The map information 30a includes node data indicating nodes set corresponding to the end points (intersections) of roads, link data indicating information regarding roads between nodes, and shape interpolation for specifying the shape of roads between nodes. It includes point data and data indicating the features present on the road and its surroundings. The link data includes the number of lanes of the lane included in the road, the lane number of each lane counted from one of the width directions of the road (left side in the present embodiment), and the road that can be entered when the lane travels to the end point of the road. And lane information indicating the line type (line shape, color, etc.) of the lane marking that divides the lane.

  The vehicle C also includes a GPS receiver 41, a vehicle speed sensor 42, a gyro sensor 43, a camera 44, and a user I / F unit 45. The GPS receiver 41 receives radio waves from GPS satellites and outputs a signal for calculating the current position of the vehicle C via an interface (not shown). The vehicle speed sensor 42 outputs a signal corresponding to the rotational speed of the wheels provided in the vehicle C. The gyro sensor 43 outputs a signal corresponding to the angular acceleration acting on the vehicle C. The camera 44 is an image sensor that captures a front image in front of the vehicle C.

  2A to 2D are plan views showing how the camera 44 captures a front image. As shown in FIGS. 2A to 2D, the camera 44 has a field of view centered on the front front F of the vehicle C, and captures a front image showing a front image obtained by looking down at the front of the vehicle C. The front image captured by the camera 44 is output to the control unit 20 via an interface (not shown). In the present embodiment, the camera 44 is provided on the back side of the rearview mirror provided at the center position in the width direction of the vehicle C. The user I / F unit 45 includes an output device that outputs various guides based on a control signal output from the control unit 20. The output device of the user I / F unit 45 of the present embodiment includes a speaker that outputs guidance by voice and a display as a display unit that displays guidance by image. The display is installed in a direction in which the driver can visually recognize the vehicle C, and is installed so that the vertical direction and the horizontal direction of the image displayed on the display are the vertical direction and the horizontal direction in the vehicle C, respectively. . In the present embodiment, the lane directions of the lanes captured by the camera 44 are all straight and parallel to each other.

The control unit 20 executes a lane guidance display program 21. The lane guidance display program 21 includes a navigation unit 21a, a forward image acquisition unit 21b, a lane identification unit 21c, and a display control unit 21d.
The navigation unit 21a is a module that causes the control unit 20 to execute various functions necessary for guiding the planned travel route to the destination. The control unit 20 specifies the current position of the vehicle C based on output signals of the GPS receiving unit 41, the vehicle speed sensor 42, the gyro sensor 43, and the like by the function of the navigation unit 21a. And by the function of the navigation part 21a, the control part 20 specifies the road where the present position of the vehicle C exists as a traveling road with reference to the link data of the map information 30a. Further, the control unit 20 searches the planned travel route from the current position to the destination by a known route search method with reference to the map information 30a by the function of the navigation unit 21a. In the present embodiment, it is assumed that the planned travel route is searched in advance. Note that the control unit 20 may acquire the planned travel route by the function of the navigation unit 21a, and may acquire the planned travel route searched by an external computer through communication.

  The front image acquisition unit 21b is a module that causes the control unit 20 to execute a function of acquiring a front image obtained by photographing the front of the vehicle C. That is, by the function of the front image acquisition unit 21b, the control unit 20 continuously acquires the front image data captured by the camera 44 every predetermined time period.

  FIG. 3A is a diagram illustrating a front image. When the vehicle C travels horizontally, the upper part in the vertical direction on the bisector that bisects the front image in the horizontal direction indicates the front front F of the camera 44 (the center position in the width direction of the vehicle C). A vanishing point exists on a bisector that bisects the front image in the horizontal direction. When the vehicle C travels horizontally, the lateral position of the front image corresponds to the horizontal position in the field of view of the camera 44, and particularly corresponds to the position of the lane in the width direction on the lane. On the other hand, the vertical position of the front image depends on the vertical position in the field of view and the distance from the camera 44. Therefore, the higher the position in the vertical direction of the front image, the farther the position on the front side in the traveling direction of the vehicle C is. In the present embodiment, the midpoint CC of the lower side of the front image indicates the center position of the vehicle C in the width direction. In the example of FIG. 3A, five lane marking images BL appear in the front image, and four lane images sandwiched in the horizontal direction by the lane marking images BL appear.

  The lane specifying unit 21c is a module that causes the control unit 20 to execute a function of specifying, in the front image, an image of a recommended lane to be changed from the traveling lane in which the vehicle C is currently traveling. That is, by the function of the lane specifying unit 21c, the control unit 20 recognizes the lane marking line image BL from the front image using a known line recognition method such as Hough transform, and is sandwiched between the lane marking image BL. Is identified as the lane image. Note that the control unit 20 may recognize the lane marking image BL with reference to the line type of the lane marking indicated by the lane information of the map information 30a by the function of the lane specifying unit 21c. Furthermore, by the function of the lane specifying unit 21c, the control unit 20 specifies that the image of the lane closest to the midpoint CC of the lower side of the front image among the lane images is the image of the traveling lane. Further, by the function of the lane specifying unit 21c, the control unit 20 specifies the lane number of the traveling lane by counting from the leftmost lane image to the traveling lane image in order in the front image.

  Further, the control unit 20 specifies the recommended lane based on the planned travel route searched in advance by the function of the navigation unit 21a by the function of the lane specifying unit 21c. That is, by the function of the lane identification unit 21c, the control unit 20 identifies a road that should travel next to the traveling road on which the vehicle C is currently traveling on the planned traveling route, and selects a lane that can enter the road. Identify as recommended lane. Then, by the function of the lane specifying unit 21c, the control unit 20 specifies, as the recommended lane image, the lane images counted in order of the recommended lane number from the leftmost lane image in the forward image.

  The display control unit 21d is a module that causes the control unit 20 to execute a function of causing the user I / F unit 45 to display a front image in which a guide line including a recommended lane side guide line portion indicating a recommended lane image in the front image is superimposed. is there. Specifically, by the function of the display control unit 21d, the control unit 20 performs a process of displaying the front image on which the guide line is superimposed on the user I / F unit 45 every time the front image is acquired at a predetermined time period. To do. Note that the midpoint CC of the lower side of the front image always indicates the center position in the width direction of the vehicle C in any front image taken at any time period. Further, when the vehicle C moves in the width direction of the lane, the image BL of the lane markings in the front image moves in the horizontal direction.

By the function of the display control unit 21d, the control unit 20 guides the recommended lane side in the horizontal direction of the image of the recommended lane depending on whether or not another lane (intervening lane) exists between the traveling lane and the recommended lane. The overlapping position of the line part is changed. Table 1 is a table showing the overlapping position of the recommended lane side guide line portion in the horizontal direction of the recommended lane image for each number of intervening lanes.

  As shown in Table 1, by the function of the display control unit 21d, the control unit 20 causes the horizontal center in the recommended lane image when there are no intervening lanes, that is, when one or more intervening lanes do not exist. Is the superimposition position of the recommended lane side guide line portion. Hereinafter, a guide line generated by the control unit 20 using the function of the display control unit 21d when there are no intervening lanes will be described.

  As shown in FIG. 2A, when the traveling lane (lane number: 3) and the recommended lane (lane number: 2) are adjacent to each other, there are zero intervening lanes. In this case, as shown in FIG. 4A, the traveling lane image (upward hatching) and the recommended lane image (downward hatching) are also adjacent in the horizontal direction in the front image. In the present embodiment, the control unit 20 specifies the center position in the horizontal direction of the image of the recommended lane by the following procedure by the function of the display control unit 21d. First, as shown in FIG. 3C, the control unit 20 generates auxiliary lines (two-dot chain lines) at a plurality of heights in the vertical direction that cross the image of the recommended lane in the horizontal direction in the front image by the function of the display control unit 21d. Then, the intersection (white circle) between the auxiliary line and the image of the respective division lines on the left and right of the recommended lane is specified. Then, by the function of the display control unit 21d, the control unit 20 causes the horizontal center point (white triangle) between the intersections (white circles) of the auxiliary lines and the image of the left and right partition lines of the recommended lanes for each auxiliary line. And a straight line connecting the midpoints (white triangles) is specified as the center line RC (one-dot chain line) of the recommended lane. This center line RC indicates the center position in the horizontal direction of the image of the recommended lane in the front image, and indicates the center position in the width direction of the recommended lane in real space.

  3A and 4A show front images in the case of FIG. 2A. In FIG. 3A, a region partitioned by a lane marking image BL sandwiching the midpoint CC of the lower side indicating the center position in the width direction of the vehicle C is a traveling lane image, and is on the left side of the traveling lane image. The image of the lane adjacent to is the recommended lane image. As shown in the enlarged views of the recommended lane images in FIG. 3A and FIG. 4A, the control unit 20 uses the function of the display control unit 21d to cause the control unit 20 to position the recommended lane on the center line RC in the front image and A front end point FE is set at a certain position H in the direction. Specifically, by the function of the display control unit 21d, the control unit 20 generates a horizontal auxiliary line S at a certain position H in the vertical direction of the front image, and at the intersection of the auxiliary line S and the center line RC of the recommended lane. The front end point FE is set. Therefore, the front side end point FE indicates a position in the recommended lane. The fixed position H is independent of the front image.

  With the function of the display control unit 21d, the control unit 20 is set to a position on the center line RC of the recommended lane in the front image and a position where the Euclidean distance from the front end point FE becomes the predetermined value Y as shown in FIG. One change point K1 is set. Note that the predetermined value Y is independent of the front image. Then, by the function of the display control unit 21d, the control unit 20 sets a linear recommended lane side guide line portion RL between the front end point FE and the first change point K1 on the center line RC as shown in FIG. 3A. Generate. As described above, when the number of intervening lanes is zero, the control unit 20 uses the function of the display control unit 21d to set the horizontal center position in the recommended lane image as the superimposed position of the recommended lane side guide line portion RL. Can do.

  As shown in FIG. 3A, the control unit 20 sets the rear end point BE at the midpoint CC of the lower side of the front image indicating the center position in the width direction of the vehicle C by the function of the display control unit 21 d. Further, as shown in FIG. 3A, the function of the display control unit 21d causes the control unit 20 to indicate a position on the rear side of the first change point K1 and the front side of the rear end point BE in the travel lane. Two change points K2 are set. That is, by the function of the display control unit 21d, the control unit 20 causes the second change point K2 in the front image at a position below the first change point K1 in the vertical direction and above the lower side of the front image in the vertical direction. Set. Further, by the function of the display control unit 21d, the control unit 20 connects the image BL of the lane marking that exists between the travel lane and the recommended lane, and the first change point K1 and the second change point K2 in the front image. The acute angle θ formed by the straight line (intersection line portion CL) is made equal to a predetermined angle. In the present embodiment, the control unit 20 sets the second change point K2 on a bisector that bisects the front image in the horizontal direction by the function of the display control unit 21d. That is, the second change point K2 is set to indicate the position of the front front F at the center position in the width direction of the vehicle C. Further, the predetermined angle is independent of the front image. It is desirable that the predetermined angle is closer to 90 degrees, and in the present embodiment, the predetermined angle is 60 degrees. The acute angle θ is formed around the intersection of the lane marking image BL existing between the travel lane and the recommended lane and a straight line (intersection line portion CL) connecting the first change point K1 and the second change point K2. It refers to two small corners of 90 degrees or less among the four corners.

  As shown in FIG. 3A, the control unit 20 uses the function of the display control unit 21d to cause the front end point FE, the first change point K1, the second change point K2, and the rear end point BE to connect to each other with a broken line and a thin line. A line GL is generated. In this case, the guide line GL includes a recommended lane side guide line portion RL between the front end point FE and the first change point K1, and an intersection line portion CL connecting the first change point K1 and the second change point K2. And the nearest portion AL between the second change point K2 and the rear end point BE. The intersecting line portion CL may be a straight line or a curve connecting the first change point K1 and the second change point K2.

  Further, as shown in FIGS. 3B and 4A, the control unit 20 generates an arrow-shaped guide line gl based on the thin-line guide line GL by the function of the display control unit 21d. In the present embodiment, the arrow-shaped guide line gl is generated so as to be symmetric with respect to the thin-line guide line GL. The head of the arrow has a triangular shape, and the apex angle is the front end point FE. A portion of the arrow-shaped guide line gl corresponding to the recommended lane-side guide line portion RL is referred to as an arrow-shaped recommended lane-side guide line portion rl. With the function of the display control unit 21d, the control unit 20 superimposes an arrow-shaped guide line gl on the front image and causes the user I / F unit 45 to display it. With the function of the display control unit 21d, the control unit 20 generates an arrow-shaped guide line gl synchronized with the front image for each of the front images continuously acquired for each time period, and the arrow-shaped guide line The front image superimposed with gl is continuously updated.

  Next, the guide line gl generated by the control unit 20 using the function of the display control unit 21d when there are two or more intervening lanes will be described. 2B and 4B show a plan view of a road and a front image (enlarged view of an image of a recommended lane) when there are two intervening lanes. In FIG. 2B, there are two intervening lanes (lane numbers: 2 and 3) between the traveling lane (lane number: 4) and the recommended lane (lane number: 1). As shown in FIG. 4B, when there are two intervening lanes, there are two intervening lane images between the traveling lane image (upward hatching) and the recommended lane image (lower right hatching) in the front image. To do.

  As shown in Table 1, by the function of the display control unit 21d, the control unit 20 allows the image of the traveling lane from the center position in the horizontal direction in the recommended lane image when there are two or more intervening lanes. The position corrected to the opposite side is set as the superimposed position of the recommended lane side guide line portion RL. That is, as shown in FIG. 3C, when the control unit 20 identifies the center line RC of the recommended lane by the function of the display control unit 21d, the center line RC is laterally moved to the opposite side of the traveling lane image by a predetermined distance a. An outer reference line SO (broken line) that is a straight line that has been translated is generated. Note that the function of the display control unit 21d causes the control unit 20 to specify an intersection between the image BL of the left and right lane markings of the recommended lane and the lower side of the front image, and a predetermined ratio (for example, 10%) to the interval W between the intersections. ) Is defined as a predetermined distance a.

  Then, by the function of the display control unit 21d, the control unit 20 sets the front end point FE at the position on the outer reference line SO in the front image and the fixed position H in the vertical direction of the front image as shown in FIG. 4B. To do. Further, by the function of the display control unit 21d, the control unit 20 sets the first change point K1 at a position on the outer reference line SO in the front image and a position where the Euclidean distance from the front side end point FE becomes the predetermined value Y. Then, a straight recommended lane side guide line portion RL is generated between the front end point FE and the first change point K1 on the outer reference line SO. As described above, when there are two or more intervening lanes, the control unit 20 corrects the position corrected from the center position in the horizontal direction in the recommended lane image to the opposite side of the traveling lane image by the function of the display control unit 21d. The superimposition position of the recommended lane side guide line portion RL can be set. When the recommended lane side guide line part RL is generated, the control unit 20 generates the intersection line part CL and the nearest part AL by the function of the display control part 21d, as in the case where there are no intervening lanes, and the recommended lane. A thin guide line GL including the side guide line part RL, the intersection line part CL, and the nearest part AL is generated. Further, by the function of the display control unit 21d, the control unit 20 generates an arrow-shaped guide line gl with respect to the thin guide line GL, and displays a front image in which the arrow-shaped guide line gl is superimposed on the user I / It is displayed on the F unit 45.

  Note that when there is even one intervening lane, the intersection line portion CL intersects a plurality of lane marking images BL existing between the recommended lane and the traveling lane. By the function of the display control unit 21d, the control unit 20 specifies the acute angle θ having the smallest angle among the acute angles θ formed at the points where the intersecting line portion CL and the plurality of partition line images BL intersect, The second change point K2 is set so that the acute angle θ is a predetermined angle (60 degrees).

  Next, when there is one intervening lane and there is no circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane, the guide line gl generated by the control unit 20 by the function of the display control unit 21d. Will be described. The case where there is one intervening lane means that there are fewer intervening lanes than two (M = 2) and one or more (N = 1). 2C and 4C are a plan view of a road and a front image (enlargement of an image of a recommended lane) when there is one intervening lane and there is no circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane. Figure). In FIG. 2C, there is one intervening lane (lane number: 2) between the traveling lane (lane number: 3) and the recommended lane (lane number: 1). As shown in FIG. 2C, when the recommended lane is a lane at the end of the road, there is no circumscribed lane.

  As shown in Table 1, by the function of the display control unit 21d, the control unit 20 has one intervening lane and there is no circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane. The position corrected from the center position in the horizontal direction in the recommended lane image to the opposite side of the traveling lane image is set as the superimposed position of the recommended lane side guide line portion RL. That is, as in the case where there are two or more intervening lanes, the control unit 20 uses the function of the display control unit 21d so that the center line RC of the recommended lane is opposite to the image of the traveling lane by a predetermined distance a as shown in FIG. 4C. The recommended lane side guide line portion RL is generated on the outer reference line SO that has been translated in the horizontal direction. When the recommended lane side guide line part RL is generated, the control unit 20 generates the intersection line part CL and the nearest part AL by the function of the display control part 21d, as in the case where there are no intervening lanes, and the recommended lane. A fine guide line GL including the side guide line part RL, the intersection line part CL, and the nearest part AL is generated. Further, by the function of the display control unit 21d, the control unit 20 generates an arrow-shaped guide line gl with respect to the thin guide line GL, and displays a front image in which the arrow-shaped guide line gl is superimposed on the user I / It is displayed on the F unit 45.

  Next, when there is one intervening lane and there is a circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane, the guide line gl generated by the control unit 20 by the function of the display control unit 21d. Will be described. 2D and 4D show a plan view of a road and a front image (enlargement of an image of a recommended lane) when there is one intervening lane and there is a circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane. Figure). In FIG. 2D, there is one intervening lane (lane number: 3) between the traveling lane (lane number: 4) and the recommended lane (lane number: 2). As shown in FIG. 2D, there is a circumscribed lane (lane number: 1) adjacent to the recommended lane from the opposite side of the traveling lane. In this case, as shown in FIG. 4D, the circumscribed lane image (vertical hatching) is adjacent to the recommended lane image in the front image from the opposite side of the traveling lane image.

  As shown in Table 1, by the function of the display control unit 21d, the control unit 20 has one intervening lane, and when there is a circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane, The position corrected from the lateral center position in the recommended lane image to the image side of the travel lane is set as the superimposed position of the recommended lane side guide line portion RL. That is, by the function of the display control unit 21d, the control unit 20 causes the inner reference line SI (broken line) translated from the center line RC of the recommended lane to the image side of the travel lane in the horizontal direction by a predetermined distance b as shown in FIG. 3C. Is generated. Then, by the function of the display control unit 21d, the control unit 20 sets the front-side end point FE at a position on the inner reference line SI in the front image and a fixed position H in the vertical direction of the front image as shown in FIG. 4D. To do. Further, by the function of the display control unit 21d, the control unit 20 sets the first change point K1 at a position on the inner reference line SI in the front image and a position where the Euclidean distance from the front side end point FE becomes the predetermined value Y. Then, a straight recommended lane side guide line portion RL is generated between the front end point FE and the first change point K1 on the inner reference line SI. As described above, the function of the display control unit 21d allows the control unit 20 to display an image of a recommended lane when there is one intervening lane and there is a circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane. The position corrected from the center position in the horizontal direction to the image side of the traveling lane can be set as the superimposed position of the recommended lane side guide line portion RL.

  When the recommended lane side guide line part RL is generated, the control unit 20 generates the intersection line part CL and the nearest part AL by the function of the display control part 21d, as in the case where there are no intervening lanes, and the recommended lane. A thin guide line GL including the side guide line part RL, the intersection line part CL, and the nearest part AL is generated. Further, by the function of the display control unit 21d, the control unit 20 generates an arrow-shaped guide line gl that is symmetric with respect to the thin guide line GL as shown in FIG. 4D, and superimposes the arrow-shaped guide line gl. The front image is displayed on the user I / F unit 45.

  In the above configuration, the function of the display control unit 21d recommends that the control unit 20 avoids misrecognizing that the intervening lane is a recommended lane when an intervening lane exists between the recommended lane and the traveling lane. The overlapping position of the recommended lane side guide line portion RL in the lateral direction of the lane image is changed. Accordingly, it is possible to prevent erroneous recognition of the number of lanes to be changed to be less than the original, and the vehicle can be reliably guided to the recommended lane.

  Further, the function of the display control unit 21d allows the control unit 20 to set the position of the center in the horizontal direction in the recommended lane image as the superimposed position of the recommended lane side guide line portion RL when one or more intervening lanes do not exist. . Here, when one or more intervening lanes do not exist, it can be said that the travel lane and the recommended lane are close to each other and the image of the recommended lane appears large in the front image (FIG. 4A). The larger the recommended lane image appears in the front image, the lower the possibility of erroneous recognition of the recommended lane image indicated by the recommended lane side guide line portion RL. As described above, when the possibility of erroneously recognizing the recommended lane image is reduced, the horizontal center position in the recommended lane image is set as the superimposed position of the recommended lane side guide line portion RL (FIG. 4A). The driver can be made aware that the center lane in the width direction of the recommended lane should be driven without causing the intervening lane to be erroneously recognized as the recommended lane.

  On the other hand, when there are two or more intervening lanes, it can be said that the travel lane and the recommended lane are far away, and the image of the recommended lane appears small in the front image. The smaller the recommended lane image appears in the front image, the higher the possibility of erroneous recognition of the recommended lane image indicated by the recommended lane side guide line portion RL. In this way, when the possibility of misrecognizing the recommended lane image is high, the position of the recommended lane side guide line is corrected from the center position in the horizontal direction in the recommended lane image to the opposite side of the traveling lane image. If it is set as the overlapping position of RL (FIG. 4B), it can be prevented that the intervening lane is erroneously recognized as the recommended lane. Accordingly, it is possible to prevent erroneous recognition of the number of lanes to be changed to be less than the original, and the vehicle can be reliably guided to the recommended lane.

  However, if the number of intervening lanes is one or more due to the function of the display control unit 21d, the control unit 20 images the traveling lane from the center position in the horizontal direction in the recommended lane image. The position corrected to the side is set as the superimposed position of the recommended lane side guide line portion RL (FIG. 4D). In this way, the position corrected from the lateral center position in the recommended lane image to the image side of the travel lane is set as the overlap position of the recommended lane side guide line portion RL, so that the opposite of the travel lane with respect to the recommended lane. It is possible to prevent the driver from misrecognizing that the circumscribed lane adjacent from the side is the recommended lane. Here, if there are fewer than two intervening lanes, the driver can clearly recognize the image of the intervening lane adjacent to the recommended lane in the front image. Therefore, when there are less than two intervening lanes, the position corrected from the lateral center position in the recommended lane image to the image side of the traveling lane is recommended as the superimposed position of the recommended lane side guide line portion RL. The driver can clearly recognize that the lane side guide line portion RL does not indicate the intervening lane adjacent to the recommended lane (FIG. 4D). Therefore, when the number of intervening lanes is less than 2, the position corrected from the lateral center position in the recommended lane image to the image side of the traveling lane is set as the superimposed position of the recommended lane side guide line portion RL. Thus, the recommended lane can be recognized accurately.

  However, even if there are fewer than two intervening lanes, if there is no circumscribed lane adjacent to the recommended lane from the opposite side of the driving lane, there will be an adjacent lane from the opposite side of the driving lane to the recommended lane. There is no possibility of misrecognized by the driver as a recommended lane. Therefore, the function of the display control unit 21d allows the control unit 20 to travel from the center position in the horizontal direction in the recommended lane image when there are no intervening lanes even when there are fewer intervening lanes. The position corrected to the opposite side of the lane image is set as the superimposed position of the recommended lane side guide line portion RL (FIG. 4C).

(2) Lane guidance display processing:
Next, the lane guidance display process executed by the function of the lane guidance display program 21 will be described. FIG. 5 is a flowchart of the lane guidance display process. The lane guidance display process is a loop process that is executed each time the control unit 20 acquires a front image at a predetermined time period by the function of the front image acquisition unit 21b. With the function of the front image acquisition unit 21b, the control unit 20 acquires a front image captured by the camera 44 (S100). Next, the control unit 20 identifies an image of a traveling lane in which the vehicle C is currently traveling in the front image by the function of the lane identifying unit 21c (S105). Specifically, the control unit 20 uses the function of the lane specifying unit 21c to make the middle of the lower side of the front image indicating the center position in the width direction of the vehicle C out of the lane images specified by recognizing the lane markings in the front image. The image of the lane closest to the point CC is specified as the image of the traveling lane. Further, the control unit 20 specifies an image of a recommended lane that the vehicle C should travel in the front image by the function of the lane specifying unit 21c (S110). Specifically, the control unit 20 specifies the lane number of the recommended lane on the traveling road based on the planned traveling route searched in advance by the function of the lane identifying unit 21c. Then, by the function of the lane specifying unit 21c, the control unit 20 specifies the lane image corresponding to the lane number of the recommended lane among the lane images specified in the forward image as the recommended lane image.

  Next, the control unit 20 specifies the center line RC of the recommended lane in the front image by the function of the display control unit 21d (S115). Specifically, by the function of the display control unit 21d, the control unit 20 causes the left and right sides of the auxiliary line and the recommended lane for each of a plurality of auxiliary lines (two-dot chain lines) in the vertical direction of the front image, as shown in FIG. 3C. An intersection point (white circle) with the image of the partition line is identified, and a straight line connecting the horizontal midpoints (white triangles) between the intersection points is identified as a center line RC (one-dot chain line) of the recommended lane.

  Next, according to the function of the display control unit 21d, the control unit 20 causes the recommended lane side guide line portion RL to depend on the number of intervening lanes and the presence or absence of a circumscribed lane adjacent to the recommended lane from the opposite side of the traveling lane. Is set (S120). That is, by the function of the display control unit 21d, the control unit 20 sets the superimposition position of the recommended lane side guide line portion RL associated with the combination of the number of intervening lanes and the presence or absence of circumscribed lanes in Table 1.

  Here, when there are no intervening lanes, the control unit 20 uses the function of the display control unit 21d to allow the control unit 20 to superimpose the recommended lane side guide line portion RL on the center line RC of the recommended lane regardless of the presence or absence of the circumscribed lane. (FIG. 4A). When there are two or more intervening lanes, the control unit 20 corrects by a predetermined distance a from the center line RC of the recommended lane to the opposite side of the image of the traveling lane regardless of the presence or absence of the circumscribed lane by the function of the display control unit 21d. The outer reference line SO is set as a superimposition position of the recommended lane side guide line portion RL (FIG. 4B). When there is one intervening lane and there is no circumscribed lane, the control unit 20 corrects by a predetermined distance a from the center line RC of the recommended lane to the opposite side of the image of the traveling lane by the function of the display control unit 21d. The outer reference line SO is set as the overlapping position of the recommended lane side guide line portion RL (FIG. 4C). On the other hand, when there is one intervening lane and there is a circumscribed lane, the control unit 20 corrects by a predetermined distance b from the center line RC of the recommended lane to the image side of the traveling lane by the function of the display control unit 21d. The inner reference line SI is set as a superimposed position of the recommended lane side guide line portion RL (FIG. 4D). In the present embodiment, the function of the display control unit 21d causes the control unit 20 to cause the shortest distance w1 in the lateral direction between the image BL of the right partition line of the recommended lane and the head of the arrow-shaped recommended lane side guide line portion rl. (FIG. 4D) and a shortest distance w2 (FIG. 4D) in the horizontal direction between the image BL of the left lane marking of the recommended lane and the head of the recommended lane-side guide line portion rl having an arrow shape are set to be equal to each other. A distance b is set. As a result, even if the width of the recommended lane image is narrowed, the recommended lane side guide line portion rl having an arrow shape can be accommodated in the recommended lane image as much as possible, and the recommended lane image can be accurately displayed by the driver. Can be recognized.

  Next, by the function of the display control unit 21d, the control unit 20 generates a recommended lane side guide line portion RL (S125). That is, by the function of the display control unit 21d, the control unit 20 causes the recommended lane side guide line portion RL set in step S120 to be superimposed (on the center line RC, on the outer reference line SO, or on the inner reference line SI), In addition, the front end point FE is set at a certain position H in the vertical direction of the front image. Further, the function of the display control unit 21d causes the control unit 20 to superimpose the recommended lane side guide line portion RL set in step S120 (on the center line RC, on the outer reference line SO, or on the inner reference line SI), In addition, a first change point K1 is set at a position where the Euclidean distance from the front end point FE becomes a predetermined value Y, and a linear recommended lane side guide line portion between the front end point FE and the first change point K1. Generate RL.

  Next, the control part 20 produces | generates the guide line gl by the function of the display control part 21d (S130). That is, the control unit 20 sets the rear end point BE to the midpoint CC of the lower side of the front image indicating the center position in the width direction of the vehicle C by the function of the display control unit 21d. Further, by the function of the display control unit 21d, the control unit 20 connects the image BL of the lane marking that exists between the travel lane and the recommended lane, and the first change point K1 and the second change point K2 in the front image. The vertical angle below the first change point K1 and the vertical direction above the lower side of the front image so that the acute angle θ formed by the straight line (crossing line portion CL) is equal to the predetermined angle (60 degrees). A second change point K2 is set at the position. More specifically, the control unit 20 sets the second change point K2 on the bisector that bisects the front image in the horizontal direction by the function of the display control unit 21d (FIG. 3A). Then, by the function of the display control unit 21d, the control unit 20 causes the front-side end point FE, the first change point K1, the second change point K2, and the rear-side end point BE to be a broken and thin guide line. A GL is generated (FIG. 3A). Further, by the function of the display control unit 21d, the control unit 20 generates an arrow-shaped guide line gl that is line-symmetric with respect to the thin-line guide line GL (FIG. 3B).

  Next, the control unit 20 superimposes the arrow-shaped guide line gl by the function of the display control unit 21d (S135). Furthermore, the control unit 20 causes the user I / F unit 45 to display a front image on which the guide line gl is superimposed by the function of the display control unit 21d (S140, FIG. 3B, and FIGS. 4A to 4D). By repeatedly executing the above processing, each time a front image is acquired, the guide line gl including the recommended lane side guide line portion RL indicating the recommended lane image included in the front image can be updated. . In addition, depending on whether or not there is an intervening lane between the driving lane and the recommended lane, the lane to be changed is changed in order to change the superimposed position of the recommended lane side guide line portion in the lateral direction of the recommended lane image. It is possible to prevent the number from being erroneously recognized less than the original, and to reliably guide the vehicle to the recommended lane.

  In the present embodiment, the position in the vertical direction of the front end point FE in the front image is maintained at the constant position H regardless of whether or not there is an intervening lane, so that the recommended lane side guide line portion rl is easily visible. can do. Further, since the length of the recommended lane side guide line portion RL is maintained at the predetermined value Y, the image of the recommended lane indicated by the recommended lane side guide line portion rl can be easily recognized. Further, regardless of whether or not there is an intervening lane, the straight line (intersection line portion CL) connecting the first change point K1 and the second change point K2 is a lane marking that exists between the recommended lane and the travel lane. Since the acute angle θ intersecting with the image BL (the minimum value of the acute angle θ in each of the plurality of lane marking images BL) is equal to or greater than a predetermined angle, the driver can easily change the lane beyond the lane marking. Can be recognized.

(3) Other embodiments:
In the above embodiment, the superimposition position of the recommended lane side guide line portion RL is set so that the recommended lane side guide line portion RL translates in the horizontal direction depending on whether or not an intervening lane exists. The control unit 20 may set the overlapping position of the recommended lane side guide line part RL so that the recommended lane side guide line part RL rotates by the function of the display control unit 21d. For example, the control unit 20 may set the overlap position of the recommended lane side guide line part RL so that the recommended lane side guide line part RL rotates around the first change point K1 by the function of the display control unit 21d. Even in this case, by the function of the display control unit 21d, the control unit 20 gives a rotation angle away from the image of the travel lane, so that the opposite side of the image of the travel lane at the superimposed position of the recommended lane side guide line portion RL Can be corrected. Further, by the function of the display control unit 21d, the control unit 20 corrects the traveling lane image side at the superimposed position of the recommended lane side guide line portion RL by giving a rotation angle approaching the traveling lane image. Can do. Further, by the function of the display control unit 21d, the control unit 20 may correct the overlapping position of only a part of the recommended lane side guide line portion RL to the image side of the travel lane or the opposite side of the image of the travel lane. .

  In the embodiment, the predetermined distance a which is a distance for correcting the overlapping position of the recommended lane side guide line portion RL to the opposite side of the image of the traveling lane is set to the width (interval W) of the recommended lane image on the lower side of the front image. However, the control unit 20 may set the predetermined distance a regardless of the image width of the recommended lane by the function of the display control unit 21d. By the function of the display control unit 21d, the control unit 20 causes the recommended lane to be independent of the shortest distances w1 and w2 (FIG. 4D) between the recommended lane side guide line portion rl having the arrow shape and the left and right partition line images of the recommended lane. You may set the predetermined distance b which is the distance which correct | amends the superimposition position of the side guide line part RL to the image side of a driving | running lane. That is, it is not always necessary to set the overlapping position of the recommended lane side guide line part RL so that the recommended lane side guide line part rl having the arrow shape is within the image of the recommended lane. If there is only one intervening lane, even if part of the arrow-shaped recommended lane side guide line portion rl protrudes into the image of the intervening lane, the arrow-shaped recommended lane side guide line portion rl is This is because it can be clearly recognized that this image is not pointed to.

  Furthermore, the function of the display control unit 21d allows the control unit 20 to set the superimposition position of the recommended lane side guide line portion RL according to at least whether or not there is an intervening lane, and depending on the number of intervening lanes. It is not necessary to set the overlapping position of the recommended lane side guide line portion RL. For example, if there is at least one intervening lane, the control unit 20 uses the function of the display control unit 21d to determine the overlap position of the recommended lane side guide line portion RL regardless of the number of intervening lanes or the presence of circumscribed lanes. You may correct | amend to the other side of this image. If the overlap position of the recommended lane side guide line portion RL is corrected to the opposite side of the image of the driving lane, the number of lanes to be changed can be prevented from being erroneously recognized, regardless of the number of intervening lanes. Because it can. Furthermore, the threshold value of the intervening lane for changing the overlapping position of the recommended lane side guide line portion RL is not limited to the number in Table 1. For example, since the possibility of erroneously recognizing a recommended lane changes according to the lane width and lane direction, the threshold value of the intervening lane that changes the overlapping position of the recommended lane side guide line portion RL according to the lane width and lane direction May be adjusted.

  By the function of the display control unit 21d, the control unit 20 determines the vertical position of the front end point FE in the front image, the length of the recommended lane side guide line portion RL, the first change point K1, and the second change point K2. The magnitude of the acute angle θ formed by the connecting straight line (intersection line portion CL) may not be kept constant. This is because the vehicle can be reliably guided to the recommended lane by changing the overlapping position of the recommended lane side guide line portion RL depending on whether or not there is an intervening lane without maintaining these constant. . Further, the control unit 20 may not set the second change point K2 by the function of the display control unit 21d, and may directly connect the first change point K1 and the rear end point BE.

  With the function of the lane specifying unit 21c, the control unit 20 may specify the lane that the vehicle C should travel as the recommended lane, and when there is a lane that should enter the intersection ahead of the vehicle C in the planned travel route, The lane may be specified as a recommended lane when approaching the intersection within a predetermined distance. Further, the control unit 20 may specify a lane that can travel more safely or smoothly than other lanes as a recommended lane by the function of the lane specifying unit 21c. With the function of the display control unit 21d, the control unit 20 may generate a broken line or a chain guide line gl connecting the front end point and the rear end point. Further, the control unit 20 may superimpose the thin guide line GL on the front image as it is by the function of the display control unit 21d.

  DESCRIPTION OF SYMBOLS 10 ... Navigation apparatus, 20 ... Control part, 21 ... Lane guidance display program, 21a ... Navigation part, 21b ... Front image acquisition part, 21c ... Lane identification part, 21d ... Display control part, 30 ... Recording medium, 30a ... Map information , 41 ... receiving part, 42 ... vehicle speed sensor, 43 ... gyro sensor, 44 ... camera, 45 ... user I / F part, BE ... rear end point, BL ... image of lane marking, C ... vehicle, CC ... midpoint, CL: intersection line part, FE: front end point, GL, gl ... guide line, H: fixed position, K1 ... first change point, K2 ... second change point, RC ... center line, RL ... recommended lane side guide line portion.

Claims (5)

Forward image acquisition means for acquiring a forward image obtained by photographing the front of the vehicle;
Lane identifying means for identifying in the front image an image of a recommended lane that the vehicle should change from a traveling lane in which the vehicle is currently traveling;
Display control means for causing the display unit to display the front image in which a guide line including a recommended lane side guide line part indicating the image of the recommended lane in the front image is included,
Wherein the display control unit,
When there are no more than N (N is a natural number) other lanes between the travel lane and the recommended lane, the horizontal center position of the recommended lane image is set to the recommended lane side guide line portion. The superposition position,
When there are N or more other lanes between the travel lane and the recommended lane, a position corrected from the center position in the horizontal direction in the image of the recommended lane to the opposite side of the image of the travel lane The superimposition position of the recommended lane side guide line part,
Lane guidance display system. The display control means has an image of the recommended lane when there are fewer than M (M is a natural number larger than N) and there are N or more other lanes between the travel lane and the recommended lane. The position corrected from the center position in the horizontal direction to the image side of the travel lane as the superimposed position of the recommended lane side guide line portion,
The lane guidance display system according to claim 1 . The display control means is a case where there are fewer than M and N or more other lanes between the travel lane and the recommended lane, and from the opposite side of the travel lane to the recommended lane When there is no adjacent lane, the position corrected from the lateral center position in the recommended lane image to the opposite side of the traveling lane image is set as the superimposed position of the recommended lane side guide line portion.
The lane guidance display system according to claim 2 . A front image acquisition means for acquiring a front image obtained by photographing the front of the vehicle; and
Lane identification means comprises a lane identification step of the vehicle is the vehicle from the travel lane currently traveling is specified in the front image the image of the recommended lane to be changed lanes,
A display control step for causing the display unit to display the front image in which a guide line including a recommended lane side guide line portion indicating the recommended lane image in the front image is displayed on a display unit,
The display control means includes
When there are no more than N (N is a natural number) other lanes between the travel lane and the recommended lane, the horizontal center position of the recommended lane image is set to the recommended lane side guide line portion. The superposition position,
When there are N or more other lanes between the travel lane and the recommended lane, a position corrected from the center position in the horizontal direction in the image of the recommended lane to the opposite side of the image of the travel lane The superimposition position of the recommended lane side guide line part,
Lane guidance display method. A front image acquisition means for acquiring a front image obtained by photographing the front of the vehicle; and
Lane identification means comprises a lane identification function that identifies the image of the recommended lane vehicle should the vehicle lane change from traveling lane currently traveling in the front image,
A display control means for causing a computer to realize a display control function for causing the display unit to display the front image in which a guide line including a recommended lane side guide line portion indicating the recommended lane image in the front image is displayed;
Wherein the display control unit,
When there are no more than N (N is a natural number) other lanes between the travel lane and the recommended lane, the horizontal center position of the recommended lane image is set to the recommended lane side guide line portion. The superposition position,
When there are N or more other lanes between the travel lane and the recommended lane, a position corrected from the center position in the horizontal direction in the image of the recommended lane to the opposite side of the image of the travel lane The superimposition position of the recommended lane side guide line part,
Lane guidance display program.

Images