JP2010185761A - Navigation system, road map display method - Google Patents

Abstract

The present invention provides a navigation system and a road map display method in which a driver can easily grasp the relationship between a scene being viewed and a shooting range of a camera.
A navigation system 100 for displaying a current position of a host vehicle on a road map 13 includes a shooting range specifying unit 31 for specifying a shooting range based on a current position and an angle of view of a camera 25 that captures the surroundings of the host vehicle. Image area determining means 32 for determining an area on the road map corresponding to the shooting range, object generating means 35 for generating an object 12 indicating the area on the road map 13, and display for displaying the road map 13 including the object 12 And means 37, 29.
[Selection] Figure 1

Description

  The present invention relates to a navigation system that displays the current position of a host vehicle on a road map, and more particularly, to a navigation system and a road map display method that can present a shooting range shot by a camera.

  The navigation system emphasizes and displays the road map around the vehicle position and the route to the destination on the road map to assist the driver in grasping the traveling direction. Although the position of the host vehicle is displayed on the road map, a navigation system has been devised that displays the right turn direction or the left turn direction on the road map when making a right or left turn along the route to the destination (see, for example, Patent Document 1). .) Patent Document 1 discloses a navigation device that, when there are successive intersections to be guided, enlarges and displays the previous intersection and guides the traveling direction of the next intersection with an arrow.

  By the way, in a vehicle equipped with a camera, an image captured by the camera may be displayed on a display device in the vehicle. For example, in a system called night view, when a pedestrian is detected from a captured image, image processing is performed so as to emphasize the pedestrian in the image, and the image can be displayed on a display device.

In addition, a technique has been considered in which image data captured by a camera is stored in association with position information using an on-vehicle camera, and an image is displayed on a travel locus of a road map (for example, Patent Documents). 2). After traveling, the driver can easily grasp the relationship between the position on the traveling locus and the image.
Japanese Patent No. 3791196 JP-A-9-179491

  However, in the image processing system described in Patent Document 2, since past images are displayed in association with past travel trajectories, it does not provide driving assistance when actually traveling in the place.

  Therefore, in a vehicle equipped with a camera, it is desirable to guide the driver while displaying the image captured by the camera and the road map in association with each other and grasping the relationship between the image and the road map. However, since the angle of view of the camera is relatively narrow, even if the image captured by the camera is simply displayed, the captured image is different from the region viewed by the driver and the region captured by the camera. It is difficult to grasp which area of the map.

  In addition, images captured by the camera may include objects such as pedestrians and other vehicles. When the distance from the object is short, the size and presence of the object can be confirmed (the camera has an angle of view). Therefore, there is a difference between the viewed scene and the image, and there is a problem that the driver may feel uncomfortable. Further, when a large object such as another vehicle is close to the camera, the other vehicle occupies most of the image, and there is a possibility that the driver may be confused even if it is displayed in cooperation with the road map.

  In view of the above problems, an object of the present invention is to provide a navigation system and a road map display method in which a driver can easily grasp the relationship between a scene being viewed and a shooting range by a camera.

  In view of the above problems, the present invention provides a navigation system for displaying a current position of a host vehicle on a road map, and a shooting range specifying unit that specifies a shooting range based on the current position and a field angle of a camera that captures the surroundings of the host vehicle. And an image area determining means for determining an area on the road map corresponding to the shooting range, an object generating means for generating an object indicating the area on the road map, and a display means for displaying the road map including the object. It is characterized by that.

  It is possible to provide a navigation system and a road map display method in which the driver can easily grasp the relationship between the scene being viewed and the photographing range of the camera.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a displayed road map 13 and an image 11 displayed in the road map 13. A feature of the navigation system 100 of the present embodiment is that the image display object 12 is displayed on the road map 13. The image display object 12 indicates the shooting range of the camera with a 2D or 3D icon.

  As shown in the figure, the vehicle position is closer to the front side of the page than the image display object 12. Therefore, the viewing area that can be seen from the driver's seat has expanded without leaving a distance from the vehicle position. On the other hand, since the image display object 12 is determined in consideration of the angle of view (narrow) of the camera 25, only the shooting range of the camera 25 smaller than the viewing area is displayed. The road map 13 is displayed at various scales, but the image display object 12 is displayed by being reduced or enlarged according to the scale.

  Therefore, the driver can grasp at a glance which region the image 11 displayed in the road map 13 corresponds to on the road map 13. Since it is possible to visually read that the shooting range of the image 11 is narrow with respect to the viewed scene, the relationship between the viewed scene and the image 11 can be easily grasped.

[Configuration of Navigation System 100]
FIG. 2 shows an example of a hardware configuration diagram of the navigation system 100. The navigation system 100 is controlled by a navigation ECU (Electronic Control Unit) 27. The navigation ECU 27 includes a GPS (Global Positioning System) receiver, a wheel speed sensor 22, a gyro sensor 23, and a map DB (Data Base) 24 via an in-vehicle LAN such as CAN or FlexRay, a dedicated line, or an AV-LAN. The input device 26, the camera ECU 28, and the display device 29 are connected.

  Any known GPS receiver 21 can be used. For example, the GPS receiver 21 determines the position (latitude / longitude / altitude) of the vehicle based on the arrival time of radio waves from four or more GPS satellites. For example, the wheel speed sensor 22 measures a magnetic flux that changes as each wheel of the vehicle rotates as a pulse, and measures the wheel speed for each wheel based on the number of pulses per unit time. The vehicle speed can be obtained by multiplying the wheel speed by the outer diameter of the tire. The gyro sensor 23 is a MEMS (Micro Electro Mechanical Systems) that detects the angular velocity when the vehicle rotates in the yawing direction or the pitching direction with respect to the road surface based on the distance of the vibration piece (between the electrodes) that changes due to the action of the Coriolis force. Entity. By integrating the detection result, the detection result is converted into an angle, that is, a traveling direction in the triaxial direction.

  The navigation ECU 27 accumulates the travel distance detected by the wheel speed sensor 22 from the position detected by the GPS receiver 21 in the travel direction detected by the gyro sensor 23, and estimates the position of the vehicle by autonomous navigation. The current position of is continuously detected. Further, the navigation ECU 27 further associates the position of the host vehicle with a predetermined link on the road map 13 by map matching to determine the final current position.

  The map DB 24 is a database of the road map 13 corresponding to the actual road network in which the node table and the link table are associated with each other. In the node table, information related to intersections between roads and points at predetermined intervals of roads is registered. The node table includes information such as a node number, node position information (coordinates), the number of nodes to be connected, a node number of each node to be connected, and a link number to be connected from the node.

  In the link table, information related to so-called roads connecting nodes is registered. The link table includes information such as a link number, start point node number, end point node number, start point latitude, start point longitude, end point latitude, end point longitude, width, number of lanes, road type, and traffic rules. Therefore, a road network corresponding to an actual road is formed by tracing the node number and the link number.

  In addition, the map DB 24 stores point data of facilities such as gas stations, parking lots, and public facilities in association with latitude and longitude. Further, address data and lot number point data to be displayed are stored in association with latitude and longitude. Such point data has drawing information indicating them and character information such as a facility name, a place name, and a road name, and the road map 13 displays icons, place names, road names, etc. formed by the drawing information. .

  The map DB 24 may be stored in a hard disk drive or the like when the vehicle is shipped or the navigation system 100 is shipped, or a part or all of the map DB 24 may be stored after the navigation system 100 is mounted on the vehicle. It may be downloaded from a predetermined server and stored.

  The input device 26 is a user interface for inputting operation information for the user to operate the navigation system 100. For example, a push button type keyboard, a trackball, a remote control, a touch panel included in the display device 29, and a voice uttered by the user. A speech recognition device or the like that inputs

  The display device 29 is an output device that forms the road map 13 with a set of points in which the luminance of each RGB color is controlled for each pixel. For example, the display device 29 is a flat panel display such as a liquid crystal display or an organic EL housed in a center cluster. In addition to these, a HUD (Head Up Display) may be provided.

[Relationship between angle of view of camera 25 and shooting range]
Next, the relationship between the angle of view of the camera 25 and the shooting range will be described. The camera 25 is fixed, for example, on the back side of a rearview mirror with the optical axis facing slightly downward in front of the vehicle. The camera 25 is a photographing device used for white line recognition and detection of pedestrians at night, but each camera may be equipped with a dedicated camera 25, and photographing is performed by switching camera parameters such as shutter speed and control gain for each frame. By doing so, you may use both. When photographing at night, the near-infrared light is preferentially applied to the front of the host vehicle by illuminating the headlight with a near-infrared projector and enabling the visible light cut filter. This facilitates detection of pedestrians.

  Although the angle of view of the camera 25 is often fixed (for example, 12 degrees), the angle of view may be adjustable by adjusting the focal length. When the angle of view is fixed, the shooting range is also fixed. Even if the angle of view is variable, the angle of view is calculated from the focal length, so that the angle of view of the camera 25 can always be detected. Therefore, the shooting range is known to the navigation system 100.

FIG. 3A is an example of a diagram schematically illustrating an angle of view in the vehicle width direction and a shooting range. It is known that the focal length and the width of the image sensor have the following relationship.
0.5 × diagonal (image circle radius) of the image pickup element = focal length _{× (tan (θ 1/2} )
Since the size and focal length of the image sensor are known, the angle of view θ ₁ can be calculated.

As shown in the figure, since the shooting range in the vehicle width direction increases as the distance L from the host vehicle increases, the shooting range in the vehicle width direction is indicated by “shooting range = L · view angle θ ₁ ”. It becomes a fan-shaped area centered on.

FIG. 3B is an example of a diagram schematically illustrating the vertical view angle θ ₂ and the imaging range. The image sensor has an angle of view θ ₂ that is similarly calculated in the vertical direction. Wherein the optical axis of the camera 25 is slightly downward from the horizontal, the downward because only the road is taken, it can identify the shooting range in the vertical direction in consideration of the height and angle theta _2. For example, the shooting range in the vertical direction is displayed as “shooting range = vehicle height + L · tan (α)”. However, α is an angle larger than the horizontal direction in the angle of view θ ₂ . From the above, an area where the imaging range in the vehicle width direction and the vertical direction are superimposed is the actual imaging range.

  Strictly speaking, the area that overlaps the imaging range in the vehicle width direction and the vertical direction in this way is the imaging range, but the imaging range in the vertical direction is limited by the road surface and the direction of the optical axis, so the imaging range in the vehicle width direction You may consider only. In this case, if the image display object 12 is displayed in 3D, the shooting range in the vertical direction is set to be approximately the same as the vehicle height.

[Detection of pedestrians]
The captured image 11 is subjected to various image processing for driving assistance. For example, the camera ECU 28 recognizes a white line from the image 11 for white line recognition, calculates white line information such as the width, the center line, and the curvature of the road, and provides the control for preventing lane departure, for example. Further, the camera ECU 28 performs an enhancement process such as detecting a pedestrian and surrounding the pedestrian with a rectangular frame from the night view image 11 for detecting a pedestrian at night, and outputs the image 11 to the display device 29. Since a pedestrian irradiated with near-infrared light is photographed with high brightness, the camera ECU 28 identifies the pedestrian by a method such as pattern matching of the shape of dense pixels with high brightness with the standard shape of the pedestrian. be able to. The night view image 11 is displayed on the entire surface of the display device 29 or in the road map 13 as shown in FIG.

[Drawing of road map 13]
Next, the drawing of the road map 13 will be described. FIG. 4 shows an example of a functional block diagram of the navigation system 100. The navigation ECU 27 is a CPU that executes a program, a RAM that serves as a program execution work area and that temporarily stores data, an input / output interface that serves as an interface for data, an ASIC (Application Specific Integrated Circuit), a CAN that communicates with the camera ECU 28, and the like. An interface, a nonvolatile memory that retains data even when the ignition is turned off, a hard disk that stores programs, a ROM, and the like are configured by a microcomputer connected by a bus.

  An imaging range specifying unit 31, an image area determining unit 32, a size adjusting unit 33, a map drawing unit 34, an object generating unit 35, an image position determining unit 36, and an image shown in FIG. A combining unit 37 is realized. Hereinafter, each function will be described in detail.

  First, generation of the road map 13 will be described. The map drawing unit 34 generates a road map 13 in a drawing range (for example, several km square) including the current position.

  The map drawing unit 34 draws the road map 13 of the display area determined according to the scale and the number of pixels of the display device 29 in several layers. The map drawing unit 34 reads out the nodes included in this display area and the links connected to the nodes from the map DB 24, forms a road network according to the link length, the connection direction between the links, the width, etc., and arranges them on one layer. The color of each link is determined according to the road type, width, etc., and a predetermined color is arranged on the guide route (each link) to the destination.

  In addition, the map drawing unit 34 arranges public facility icons, accommodation facility icons, gas station icons, station and railway line icons in different layers from the point data in the same display area according to the respective position information. To do. Further, the map drawing unit 34 arranges an address or a lot number symbol (character) on another layer. Also, a host vehicle icon indicating the host vehicle is arranged at the current position of the vehicle in the predetermined layer.

  In the case of a touch panel, a layer for displaying menu buttons is prepared, and the map drawing unit 34 generates layers in which various menu buttons are formed at predetermined positions. In this layer, east, west, south, north, and time are formed.

  As described above, when each layer is generated, the map drawing unit 34 generates a road map 13 having a predetermined resolution (eg, 640 × 480 pixels) by shading and superimposing each layer. When only the road map 13 is displayed, the data of the road map 13 is stored in the VRAM, and the display device 29 reads the data of the VRAM and repeatedly displays it at every predetermined refresh rate. On the other hand, when the image 11 is combined and displayed on the road map 13 as in the present embodiment, the image combining unit 37 combines the road map 13 and the image 11 data by storing them in the VRAM.

  For example, the navigation system 100 can automatically switch between 2D display and 3D display arbitrarily or at a predetermined place such as an intersection. In the case of 2D display, the direction of the road map 13 is switched according to the driver's setting, such as fixing the north direction upward or matching the traveling direction upward. In the case of 3D display, the generated road map 13 is coordinate-converted and displayed in a bird's-eye view looking down from above. In the case of 3D display, since features such as buildings are also displayed so as to have a height and depth, 3D icons are modeled from polygon data of the features such as buildings stored in the point data and arranged in layers. . If the viewpoint is instructed from the driver or 3D display settings, the data of the road map 13 can be generated by rendering each icon from the shape and position of the icon.

[Determination of image area according to shooting range]
Since the navigation system 100 of the present embodiment displays the image display object 12 on the road map 13, the image area determination unit 32 determines an image area corresponding to the shooting range in the road map 13.

FIG. 5A is an example of a diagram illustrating the shooting range. Since the shooting range should be based on the position of the host vehicle in the link on which the host vehicle is mapped, the shooting range specifying unit 31 specifies the link of the current position and the position on the link. In addition, the shooting range specifying unit 31 specifies the direction of the vehicle from the travel locus. The shooting range specifying unit 31 specifies the shooting range described with reference to FIG. 3 as the shooting range from this position. If necessary, the angle of view θ ₁ is determined in advance.

The image area can be determined by making this shooting range correspond to the road map 13. If the shooting range, the vehicle position, and the vehicle direction are specified, the image region determination unit 32 determines the image region as follows, for example.
The front-rear direction of the image area is determined, for example, to about 100 m ahead from the position where the road surface enters the shooting range. The position where the road surface enters the imaging range is determined from the angle of view θ ₂ , the direction of the optical axis, and the mounting height of the camera 25.
-The vehicle width direction is about the width.

  The shooting range in the height direction need not be considered in 2D display, and is about the vehicle height in 3D display. Even in 3D display, if the viewpoint is sufficiently high, the height of the image area can be ignored, so the shooting range in the height direction may be omitted. Such an image region is displayed on the road map 13 as the image display object 12.

  By the way, because buildings are lined up along the road in urban areas, the shooting range in the vehicle width direction is about the width, but in the suburbs there are no buildings along the road and the shooting range in the vehicle width direction should not be limited to the width Therefore, more preferably, the image area is determined after the imaging range is specified as follows.

FIG. 5B shows another example of a diagram illustrating the specification of the shooting range. The shooting range specifying unit 31 refers to the road map 13 and searches whether there is a feature higher than the own vehicle in the range of the angle of view θ ₁ at intervals of about 5 to 10 degrees with the current position of the own vehicle as the center. To do. Since the height of a general house is higher than the vehicle height, it may be determined whether or not there is an artificial feature. When the feature is detected at a density higher than a predetermined density (for example, when a feature along the road is detected three times consecutively by the search), the shooting range is set to about the vehicle width as shown in FIG. . When the feature along the road is not detected or when the feature is sparse, the shooting range specifying unit 31 specifies the fan-shaped shooting range as shown in FIG. Specify the shooting range up to the feature. Note that the urban area and the suburbs may be divided and the shooting range may be switched according to the current position of the vehicle.

  The image area determination unit 32 associates this shooting range with the road map 13 as in the case of FIG. Thus, by specifying the shooting range, the shooting range and the image display object 12 can be easily matched, so that it is possible to easily match the visually observed scene and the image area even in the suburbs.

[Display of Image Display Object 12]
Since the size of the image area corresponds to the scale of the road map 13, the size adjustment unit 33 adjusts the image area according to the scale of the road map 13. That is, the road map 13 is reduced / enlarged to the same scale as the current scale.

  Then, the object generation unit 35 of the map drawing unit 34 displays the image display object 12 in the image region of the road map 13 determined by the image region determination unit 32 with the size adjusted by the size adjustment unit 33. FIG. 6A shows an example of the image display object 12. FIG. 6A shows a 2D display of the road map 13. In FIG. 6A, by displaying the icon of the camera 25 in front of the host vehicle, the driver is made aware that the icon is the image display object 12. The image display object 12 may be generated in any layer, or a new layer may be provided and generated there. In any case, the presence or absence of display can be controlled by appropriate shading processing.

  In addition to the illustration shown in FIG. 6A, the image display object 12 includes a rectangular area with a lane, a predetermined transmittance set so that the road map 13 can be seen through, and a predetermined color. What is displayed may be displayed so that the driver or the occupant can grasp that the image display object 12 is displayed, such as what is displayed or only the frame of the rectangular area is emphasized. In addition, the driver | operator can select the aspect of the image display object 12 previously.

  Further, not only the image display object 12 but also a visually viewed scene may be schematically shown on the road map 13. Hereinafter, the region on the road map 13 of the visually observed scene is referred to as a viewing area. FIG. 6B is a diagram showing an example of a road map 13 in which the viewing area and the image display object 12 are shown. Since the viewing area depends on the driver's field of view, it is difficult to make it completely coincide with the driver's field of view, but in many cases it is wider than the angle of view. In addition, the general human viewing angle is about 180 degrees at the maximum, but becomes narrower during traveling, and the area between the left and right A pillars is considered as a viewing area during traveling. Therefore, the angle connecting the left and right A pillars from the driver's seat can be estimated as the viewing area. If this viewing area is corrected at the front and rear positions of the driver's seat, a more accurate viewing area can be estimated.

  As shown in the drawing, since the image display object 12 is narrower than the viewing area, the driver can visually read that the shooting range by the image 11 is narrower than the viewed scene. Therefore, it is possible to easily grasp the relationship between the scene being viewed and the image 11.

  Further, since the pedestrian is detected in the night view, if there is a pedestrian in the shooting range, the pedestrian is highlighted and displayed in the image 11. In this case, the exact distance to the pedestrian is unknown unless a stereo camera or radar is used, but is known from the position of the pedestrian in the pedestrian image 11 in the lateral direction. Further, the approximate distance from the size of the pedestrian in the image 11 to the pedestrian can be calculated. For example, the approximate distance to the pedestrian is calculated by multiplying the extension (number of pixels) of the pedestrian by a coefficient. Thus, if the position of the pedestrian can be specified, the approximate position of the pedestrian can be displayed on the image display object 12 with an icon.

  FIG. 6C is a diagram illustrating an example of the image display object 12 including the pedestrian icon 14. From the position of the pedestrian icon 14, the driver can grasp the approximate position of the pedestrian. If the image display object 12 and the image 11 are displayed on the same screen and the approximate position of the pedestrian icon 14 that is highlighted in the image 11 is indicated in the image display object 12, the driver will see the image 11. It becomes easy to grasp the correspondence of the road map 13.

[Display of image 11]
The display of the image 11 taken by the camera 25 will be described. The image display area of the image 11 on the display device 29 (upper right of the display device 29 in FIG. 1) may be determined in advance or may be automatically determined at any of the four corners closest to the image display object 12. Good. The size of the image display area is determined to be, for example, about ¼ to ８ of the number of pixels of the display device 29, or can be enlarged or reduced by dragging the frame of the image 11 using the touch panel, for example. Can be reduced.

  For example, when an instruction to display the image 11 in the road map 13 is input from the input device 26 in a state where the road map 13 is displayed on the entire surface of the display device 29 (for example, when the switch of the camera 25 is turned on). The image position determination unit 36 determines the display rear of the image 11 having a predetermined size in the road map 13. At this time, whether the image display object 12 is displayed at the same time or only the image 11 is displayed depends on the setting of the navigation system 100.

  Further, since the image 11 is displayed in a reduced size than the image 11 taken by the camera 25, the image composition unit 37 reduces the size of the image 11 according to the size of the image display area. The image composition unit 37 extracts the size of the data of the image 11 taken by the camera 25 by, for example, extracting one pixel value for every two pixels in the vertical direction and one for every two pixels in the horizontal direction. Reduce to 1/4.

  Then, the image composition unit 37 composes the road map 13 and the image 11 and displays them on the display device 29. The image composition unit 37 preferentially secures the VRAM address corresponding to the image display area determined by the image position determination unit 36 in preference to the road map 13. In this case, the road map 13 is not displayed in the image display area, but the road map 13 may be displayed in a translucent manner. In addition, the image composition unit 37 stores the data of the image 11 whose size has been reduced at the secured address. The display device 29 displays the road map 13 and the image 11 by reading out the data of the image 11, the data of the road map 13, the vertical synchronization signal and the horizontal synchronization signal in the scanning order.

  There are several possible ways of displaying the image 11 on the road map 13. For example, only the image display object 12 is displayed, only the image 11 is displayed, and the image display object 12 and the image 11 are simultaneously displayed. In the present embodiment, switching can be performed by a user's operation of the input device 26. When both the image 11 and the image display object 12 connected by the leader line are displayed by turning on the camera 25, when the driver touches the image 11, only the image 11 is erased and the driver displays the image. If the object 12 is touched, only the image display object 12 is deleted. Further, for example, when a place where the image 11 is present is touched, both the image 11 and the image display object 12 are displayed.

  Further, for example, when only the image 11 is displayed by switching on the camera 25, when the driver touches the image 11, the image display object 12 connected by the lead line is displayed together. In this case, when the image display object 12 is touched, the image display object 12 is deleted, and when the image 11 is touched, the image 11 is deleted. When the image display object 12 is touched with only the image display object 12 displayed, the image 11 is displayed in the road map 13 like a balloon.

  In this embodiment, the road map 13 and the image 11 are displayed on the same display device 29. However, the road map and the image 11 are displayed on different display devices (for example, the road map is displayed on the liquid crystal display and the image 11 is displayed on the HUD). It may be displayed. Even in this case, the navigation system 100 displays the image display object 12 on the road map 13, so that the driver can grasp the relationship between the shooting range and the sight seen.

  In the case where the scale is displayed at a minimum scale in a city or the like, the image may be scaled and converted directly so that the positional relationship is matched without generating the image display object 12 on a screen such as a bird view.

[Display Procedure of Navigation System 100]
FIG. 7 is an example of a flowchart showing a procedure for displaying the image display object 12 by the navigation system 100 of the present embodiment. The flowchart of FIG. 7 is repeatedly executed when the road map 13 is displayed.

  First, the image position determination unit 36 determines whether or not to display the image 11 (S10). The image 11 is displayed when, for example, the driver inputs an operation for displaying the image 11 from the input device 26. When the image 11 is not displayed (No in S10), the map drawing unit 34 displays a road network, facility icons, address or lot number symbols (characters), menus for each layer according to the scale and the number of pixels of the display device 29. While arranging an icon etc., the own vehicle icon is arrange | positioned at the present position of a vehicle, and the data of the road map 13 are produced | generated (S80). Then, the image composition unit 37 displays only the road map 13 on the display device 29 (S70).

  When displaying the image 11 (Yes in S10), the shooting range specifying unit 31 first specifies the shooting range (S20). The shooting range specifying unit 31 searches whether there are high features in the surrounding area and determines whether the shooting range is a rectangle or a fan shape along the road.

  Further, the image area determining unit 32 determines an image area corresponding to the shooting range in the road map 13 (S30). The image area is rectangular or fan-shaped.

  The size adjustment unit 33 adjusts the size of the image area according to the scale of the road map 13 (S40). And the map drawing part 34 produces | generates the image display object 12 of the adjusted size to a predetermined layer, and produces | generates the road map 13 (S50).

  The generated road map 13 data is sent to the image composition unit 37, and the image composition unit 37 synthesizes the image 11 reduced by the reduced display unit and the data of the road map 13 (S60). The display device 29 displays the road map 13 and the image 11 on one screen (S70).

  According to the navigation system 100 of the present embodiment, by displaying the image display object 12 on the road map 13, it is possible to determine which region the image 11 displayed in the road map 13 corresponds to on the road map 13. Can grasp at a glance. Since it is possible to visually read that the shooting range of the image 11 is narrow with respect to the viewed scene, the relationship between the viewed scene and the image 11 can be easily grasped.

  Since the camera 25 mounted on the vehicle has a relatively narrow angle of view, the driver feels the difference between the viewed scene and the image 11 as the object such as the vehicle is photographed near the camera 25. In the present embodiment, a navigation system 100 that displays such an image 11 while reducing such differences as much as possible will be described.

  FIG. 8 is an example of a diagram schematically illustrating a display method of the image 11 by the navigation system 100 according to the present embodiment. 8A shows a case where the distance between the host vehicle and the pedestrian is medium to far, FIG. 8B shows a case where the distance between the host vehicle and the pedestrian is small, and FIG. The case where the person is not included is shown respectively. As shown to Fig.8 (a), when a pedestrian exists from a middle distance to a distant place, a driver | operator can recognize a pedestrian displayed on the image 11 and a pedestrian seen visually without much discomfort. For this reason, when the distance between the host vehicle and the pedestrian is medium to far, the display is the same as in the first embodiment.

  On the other hand, when the distance between the host vehicle and the pedestrian is small as shown in FIG. 8B, the pedestrian in the image 11 has a part of the head or leg outside the angle of view as compared to the pedestrian who is visually observed. Since it is presented in a state that protrudes from the screen, it causes discomfort. Further, there is a time lag until the pedestrian enters the angle of view and the image 11 can be confirmed after the pedestrian is visually observed, and the driver is difficult to grasp the relationship between the visual observation and the image 11. Therefore, in such a case, in this embodiment, image processing is performed so that the driver's line of sight does not face the image 11 (hereinafter, this image processing is referred to as non-stimulation processing). By doing so, it is possible to prevent the driver from feeling uncomfortable with the difference between the scene viewed by the driver and the image 11.

  Further, as shown in FIG. 8C, when there is no pedestrian in the shooting range, the pedestrian is not included in the image 11, so that the driver does not feel discomfort and the image 11 is the same as in the first embodiment. Is displayed.

[Relationship between pedestrian position and non-awareness processing]
FIG. 9 shows an example of a hardware configuration diagram of the navigation system 100 of the present embodiment. In FIG. 9, the same parts as those in FIG. The navigation system 100 of this embodiment includes a millimeter wave radar 19. The millimeter wave radar 19 includes a millimeter wave band radar transmission / reception device arranged in the front grille, and detects the distance between the vehicle and the pedestrian based on the time until the transmission wave is reflected and received by the pedestrian. Further, the millimeter wave radar 19 emits a transmission wave in a pulsed manner while scanning a predetermined angle range in the left-right direction centering on the vehicle length direction (for example, a range of 15 degrees to the left and right), so there is a pedestrian The direction can also be detected. Hereinafter, the distance and direction to the pedestrian are referred to as pedestrian position information. The position information of the pedestrian may be calculated from parallax information of a laser radar or a stereo camera instead of the millimeter wave radar 19.

  FIG. 10 shows an example of a functional block diagram of the navigation system 100 in the present embodiment. 10, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted. The navigation system 100 according to the present embodiment includes a front situation determination unit 38 that determines the situation ahead of the host vehicle. The forward situation determination unit 38 determines the forward situation based on the position information of the pedestrian detected by the millimeter wave radar 19 and the imaging range specified by the image area determination unit 32.

FIG. 11 is an example of a diagram schematically illustrating an imaging range and a detection range of the millimeter wave radar 19. Since the detection range of the millimeter wave radar 19 is about 15 degrees to the left and right, generally, the distance from the pedestrian can be detected before the pedestrian enters the shooting range. In FIG. 11, the short distance is within the distance S.
Since the pedestrian A is detected at a short distance and is included in the shooting range, the image 11 is subjected to non-stimulation processing so as not to give the driver a sense of incongruity.
-Although the pedestrian B is detected at a short distance, since it is not included in the imaging range, the image 11 is not subjected to non-stimulation processing.
-Since the pedestrian C is not detected at a short distance, even if it is included in the shooting range, the image 11 is not subjected to the non-stimulation process.
Since the pedestrian D is not detected at a short distance and is not included in the shooting range, the image 11 is not subjected to a non-stimulation process.

  Thus, when the pedestrian within the distance S is included in the shooting range, the front situation determination unit 38 requests the non-stimulation processing unit 39 to non-stimulate the image 11.

[Non-stimulation process]
The non-stimulation process will be described. The non-stimulation process is a process that makes it difficult for the driver's line of sight to face the display device 29. For example, dimming of the image 11 portion of the screen, displaying a message on the image 11 portion, stopping the display of the image 11 itself (displaying the road map 13 on the entire surface), further reducing the image 11, and the like. When dimming a part of the image 11, for example, all the pixel values of the image 11 are uniformly reduced. By doing so, the same effect as that obtained by dimming only a part of the display device 29 while maintaining the color tone of the image 11 can be obtained. Further, when the camera 25 captures an image, the image 11 may be darkened by increasing the shutter speed or decreasing the gain.

  In addition, when displaying a message, for example, a character such as “Currently, an image with a sense of incongruity with the sight that is seen is displayed.” “Please do not look at” or “Please do not refer to the image” is displayed. . Further, instead of displaying, a voice message may be output from a speaker.

  The non-stimulation processing unit 39 performs non-stimulation processing on the image 11 in such a predetermined manner. Then, the image composition unit 37 composes and displays the image 11 on the road map 13 as in the first embodiment.

  FIG. 12 is an example of a flowchart illustrating a procedure for displaying the image display object 12 by the navigation system 100 according to the present embodiment. The flowchart of FIG. 12 is repeatedly executed when the road map 13 is displayed.

  In FIG. 12, the same steps as those in FIG. In this embodiment, the process is performed until the photographing range is specified (S20), the image area is determined (S30), the size of the image area is adjusted according to the scale of the road map 13 (S40), and the road map 13 is generated (S50). Similar to Example 1.

  Next, in this embodiment, the front situation determination unit 38 determines whether or not the distance to the pedestrian is within the distance S and the pedestrian is in the shooting range (S55). When this condition is satisfied, the non-emergence processing unit 39 performs, for example, a light reduction process on the pixels of the image 11 (S56).

  The subsequent processing is the same as that in the first embodiment, and the image composition unit 37 synthesizes the image 11 and the road map 13 subjected to the light reduction processing after the reduction (S60). The display device 29 displays the road map 13 and the image 11 on one screen (S70).

  According to the present embodiment, the distance to the pedestrian is detected, and when the distance to the pedestrian is close, the image 11 is subjected to a non-stimulation process, so that the difference between the scene in which the driver is visually observed and the image 11 is different. You can avoid feeling uncomfortable.

It is a figure which shows an example of the displayed road map and the image displayed in the road map. It is an example of the hardware block diagram of a navigation system. It is an example of the figure which illustrates a photography range typically. It is an example of the functional block diagram of a navigation system. It is an example of the figure explaining an imaging | photography range. It is a figure which shows an example of an image display object. It is an example of the flowchart figure which shows the procedure in which a navigation system displays an image display object. (Example 2) which is an example of the figure which shows the display method of the image by a navigation system typically. It is an example of the hardware block diagram of a navigation system (Example 2). (Example 2) which is an example of the functional block diagram of a navigation system. It is an example of the figure which shows typically the imaging | photography range and the detection range of a millimeter wave radar. (Example 2) which is an example of the flowchart figure which shows the procedure in which a navigation system displays an image display object.

DESCRIPTION OF SYMBOLS 11 Image 12 Image display object 13 Road map 21 GPS receiver 22 Wheel speed sensor 23 Gyro sensor 24 Map DB
25 Camera 26 Input device 27 Navi ECU
29 Display device 100 Navigation system

Claims (12)

A navigation system that displays the current position of the vehicle on a road map,
A shooting range specifying means for specifying a shooting range based on the current position and the angle of view of the camera shooting the surroundings of the host vehicle;
Image area determination means for determining an area on a road map corresponding to the shooting range;
Object generating means for generating an object indicating the area on a road map;
Display means for displaying a road map including the object;
A navigation system comprising: The display means displays an image captured by the camera in a road map in association with the object;
The navigation system according to claim 1. Position detecting means for detecting the position of an obstacle with respect to the host vehicle;
A forward situation determination means for determining whether the distance to the obstacle is a predetermined value or less and whether the obstacle is included in the imaging range;
If the distance to the obstacle is equal to or less than a predetermined value, and it is determined that the obstacle is included in the shooting range, a non-stimulation processing unit that performs processing for reducing visibility on the image,
The navigation system according to claim 2, further comprising: Image processing means for performing processing for emphasizing the pedestrian in the image when the pedestrian is detected from the image captured by the camera;
The navigation system according to claim 2, further comprising: When a pedestrian is detected from the image, the object generation means generates the object including an icon indicating a pedestrian.
The navigation system according to claim 4, wherein: The object generation means generates the object of a rectangular area in an urban area and generates the fan-shaped object in a suburb.
The navigation system according to any one of claims 1 to 5, wherein: The object generation means generates an icon of a visual area visually recognized from a driver's seat together with the object on a road map.
The navigation system according to any one of claims 1 to 6, wherein: When the road map can be displayed by switching to a display mode of either 2D display or 3D display,
The object generation means generates the two-dimensional or three-dimensional object according to the display mode.
The navigation system according to claim 1, wherein: The object is displayed with a leader from the image;
The navigation system according to claim 2. When the display means has a touch panel for detecting the contact position of the driver,
When contact with the image is detected, the object generation means generates the object on a road map,
The navigation system according to claim 2. When the camera is turned on,
The object generating means generates the object on a road map;
The navigation system according to claim 2. A road map display method for displaying a current position of a host vehicle on a display device,
Identifying a shooting range based on the current position and the angle of view of a camera that shoots around the vehicle; and
Determining an area on a road map corresponding to the shooting range;
Generating an object indicating the region in a road map;
Displaying a road map including the object;
A road map display method characterized by comprising: