JP2007218655A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device capable of fulfilling an original navigation function which a guide video image (moving image) has, and to provide a navigation function faithful to an actual running condition. <P>SOLUTION: The navigation device acquires the real-time video image of a part ahead of own vehicle ranging from the vicinity of the vehicle position up to a guide point, and performs navigation by using a guide video image, where guide objects are superposed on the acquired real-time video image of the part ahead of the vehicle, and is provided with a display section for displaying the guide video image; a risk assessment section for determining risk of driving; and a frame rate controller for controlling the frame rate of the guide video image to be displayed by the display section, based on the determination result by the risk assessment section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a navigation device, and more specifically, acquires a live-action image in front of the vehicle from the vicinity of the vehicle position to a guide point, and displays a guide image in which a guide object is superimposed on the acquired real-image image in front of the vehicle. The present invention relates to a navigation device that uses and navigates.

  2. Description of the Related Art Conventionally, a navigation device that displays an enlarged map (still image) on the screen when a vehicle approaches a guidance point that should turn left or right is generally used. However, in such a navigation device, the driver must compare the enlarged map (still image) with the actually visible landscape and make a decision to apply the two to each other.

  As a technique for avoiding the complexity of the judgment work as described above, a guide video obtained by acquiring a live-action video in front of the host vehicle from the vicinity of the host vehicle position to the guide point and superimposing a guide object on the acquired real-time video in front of the host vehicle There is a navigation device that performs navigation using (moving image).

  In the guidance using live-action video, the guidance video changes as the scenery that the driver actually sees changes from moment to moment. Can be easily associated with each other, and guide points can be easily identified.

  Further, if navigation is performed using the guide video (moving image) as described above, there is an advantage that the situation ahead can be understood even when the screen is viewed. That is, there are advantages that the behavior of the vehicle ahead can be seen on the screen, and the right / left turn instruction can be easily grasped.

  However, since this guidance video is only a moving image, and the display content of the screen changes from time to time, the driver tends to watch the screen. If the driver looks closely at the screen, there may be a driving risk.

In view of this, a technique has been proposed in which the driver avoids the driving danger caused by watching the moving image displayed on the screen as described above. This technology is intended for entertainment-related content such as TV images and DVD images. When the driver's line of sight directed to the screen is detected and it is determined that the user is gazing, a still image is captured from the video. Are displayed instantaneously (for example, Patent Document 1).
JP 2003-240560 A

  However, the conventional technology described above follows the changes in the scenery that the driver is viewing if the driver is gazing at the moment and switches from the guide video (video) to the enlarged map (still image) instantly. Thus, the original navigation function of the guide video (moving image) that can be enjoyed by displaying the guide video cannot be performed.

  Accordingly, the present invention has been made in view of the above problems. In other words, a navigation device that can perform the original navigation function of a guide video (moving image) is provided. In addition, a navigation device capable of performing a navigation function faithful to the actual driving situation and reducing the driving danger due to screen gaze is provided.

  The first aspect of the present invention acquires a live-action image in front of the own vehicle from the vicinity of the own vehicle position to the guide point, and performs navigation using a guide image in which a guide object is superimposed on the acquired actual image in front of the own vehicle. It is aimed at navigation devices.

  The present invention controls the frame rate of the guide video displayed on the display unit based on the display unit that displays the guide video, the risk level determination unit that determines the driving risk level, and the determination result of the risk level determination unit. A frame rate control unit.

  The risk determination unit includes a gaze situation determination unit that determines a gaze situation based on information about a user's line of sight directed to the guide video displayed by the display unit, and the frame rate control unit includes a gaze situation determination unit It is preferable to control the frame rate of the guide video displayed on the display unit based on the determination result.

  The gaze state determination unit preferably determines the gaze time, and the frame rate control unit preferably decreases the frame rate when it is determined that the gaze time is long.

  In addition, it is preferable that the gaze state determination unit determines the number of gazes per predetermined time, and the frame rate control unit lowers the frame rate when it is determined that the number of gazes per predetermined time is large.

  The risk determination unit includes a traveling state determination unit that determines a traveling state of the host vehicle, and the frame rate control unit includes a frame rate of a guide video displayed on the display unit based on a determination result of the traveling state determination unit. Is preferably controlled.

  Further, the traveling state determination unit determines whether or not the shape of the road on which the host vehicle is traveling is a curved shape, and the frame rate control unit determines that the shape of the road on which the host vehicle is traveling is a curved shape. It is preferable to reduce the frame rate.

  In addition, the traveling status determination unit determines the rank of the type of road on which the vehicle is traveling, and the frame rate control unit determines that the rank of the type of road on which the vehicle is traveling is low. It is preferable to reduce the rate.

  The traveling state determination unit determines the inter-vehicle distance between the host vehicle and the preceding vehicle, and the frame rate control unit decreases the frame rate when it is determined that the inter-vehicle distance between the host vehicle and the preceding vehicle is small. Is preferred.

  In addition, the traveling state determination unit determines whether the road on which the vehicle is traveling is congested, and the frame rate control unit determines the frame rate when the road on which the vehicle is traveling is congested. It is preferable to lower.

  In addition, it is preferable that the traveling state determination unit determines the vehicle speed of the host vehicle, and the frame rate control unit lowers the frame rate when it is determined that the vehicle speed of the host vehicle is high.

  As described above, according to the aspect of the present invention, on the basis of the driver's gaze situation directed to the screen, the guide video (moving image) is displayed on the screen without instantaneously switching from the enlarged map (still image). Controls the frame rate of the guide video (moving image). Therefore, it is possible to provide a navigation device that can perform the original navigation function of the guide video (moving image). It is also possible to avoid driving hazards caused by the driver gazing at the screen. Furthermore, the frame rate of the guide video (moving image) displayed on the screen is controlled based on the traveling state of the host vehicle. Therefore, it is possible to provide a navigation device that can perform a navigation function faithful to the actual driving situation. In other words, the risk level for driving is determined from the driving conditions such as the time and frequency of the driver's screen, the type of road that is being driven, and the distance from the vehicle ahead, and the frame rate is set appropriately based on the determination result. Control. Specifically, when the degree of danger is high, reducing the frame rate maintains the merit of easy-to-understand navigation guidance using guidance video (video), and in situations where danger is expected, the danger Can be avoided.

  It is possible to provide a navigation device that can perform the original navigation function of the guide video (moving image). In addition, it is possible to provide a navigation device that can perform a navigation function faithful to the actual driving situation.

  Hereinafter, a navigation device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing an overall configuration of a navigation device according to an embodiment of the present invention. In FIG. 1, the main device 100 controls the entire navigation device. The guide video camera 110 is for taking a picture of the front of the host vehicle, and is arranged at a position where the scene in front of the host vehicle can be shot, such as the vicinity of the rear mirror, the driver's seat, or the door mirror. Established. Further, the line-of-sight detection camera 120 is for photographing particularly the eye portion of the driver's face directed to the screen of the display unit 130, and is near the rear mirror of the own vehicle and the display unit 130 or the vicinity of the steering wheel. In the driver's face, the eye portion is particularly arranged at a position where it can be photographed.

  FIG. 2 is a block diagram showing the overall configuration of the navigation apparatus 200 according to the embodiment of the present invention. As shown in FIG. 2, the navigation device 200 includes a map storage unit 210, a position acquisition unit 220, a route search unit 230, a video acquisition unit 240, a video superimposition unit 250, a line-of-sight detection unit 260, a gaze state determination unit 270, a frame rate. A control unit 280 and a display unit 130 are provided.

  The map storage unit 210 stores a wide range of road map data (for example, three-dimensional map data) determined in advance, for example, throughout Japan. The map storage unit 210 includes a storage medium such as an HDD (Hard Disk Drive), a DVD (Digital Versatile Disk), and a semiconductor memory. The map storage unit 210 stores map information including landmarks such as road types, road shapes, intersection data, and facilities. The map information may be appropriately downloaded from the center facility by a communication unit (not shown) such as a mobile phone and stored in the map storage unit 210, for example.

  The position acquisition unit 220 is typically configured by GPS (Global Positioning System), and based on the transmission information of the artificial satellite, for example, the current position of the host vehicle represented by latitude coordinates, longitude coordinates, and altitude coordinates. calculate. In addition to the GPS, the position acquisition unit 220 may include, for example, a gyro sensor, an acceleration sensor, and a vehicle speed sensor.

  The route search unit 230 searches for a route to the destination with reference to the destination information, the current position information of the own vehicle, and the road map data stored in the map storage unit 210. In this route search, the route through the shortest distance to the destination, the optimum route when priority is given to the arrival time, the optimum route when not passing through the toll road, the optimum route when avoiding traffic congestion, or the driver A search is made for an optimal route that passes through the designated point.

  The video acquisition unit 240 acquires a landscape video in front of the vehicle taken by the guide video camera 110 shown in FIG. 1 as a video to be used for navigation guidance.

  The video superimposing unit 250 generates a guide video in which a guide object is superimposed on a live-action video in front of the host vehicle acquired by the guide video camera 110 of the video acquisition unit 240. The guidance video generation process will be described later.

  The line-of-sight detection unit 260 detects the line of sight of the driver directed to the screen of the display unit 130. FIG. 3 shows an internal configuration of the line-of-sight detection unit 260. The line-of-sight detection unit 260 includes an illumination unit (not shown), a pupil extraction unit 261, a cornea reflection image extraction unit 262, and a focus determination unit 263.

  An illumination unit (not shown) that emits invisible light such as a near-infrared LED is arranged in a coaxial system with the line-of-sight detection camera 120 of the image acquisition unit 240 and emits light toward the driver. The pupil extraction unit 261 extracts a retinal reflection image (pupil position) from the captured image captured by the line-of-sight detection camera 120 of the video acquisition unit 240. Furthermore, the cornea reflection image extraction unit 262 extracts a cornea reflection image from the vicinity of the pupil position. Then, the focus determination unit 263 calculates the degree of focus that represents the degree of focus of the corneal reflection image, determines whether the focus is in focus, and detects the line of sight.

  Note that the line-of-sight detection unit 260 detects the driver's line of sight directed to the screen of the display unit 130 by detecting, for example, the position of the eye iris captured by the line-of-sight detection camera 120 of the video acquisition unit 240. It is good also as a structure to detect. At this time, if the direction of the iris of the eye picked up by the line-of-sight detection camera 120 of the video acquisition unit 240 is facing the front, it can be detected that the line of sight of the driver is directed to the screen of the display unit 130. The line-of-sight detection method is not limited to this example, and other known techniques may be used.

  In the present embodiment, the example in which the gaze detection unit 260 has a function of detecting the driver's gaze direction has been described. However, if such a function exists outside the navigation device, the gaze detection unit 260 may It is only necessary to have at least a function of acquiring only information regarding the driver's line-of-sight direction, that is, whether or not the display unit 130 is viewed.

  Based on the detection result of the line-of-sight detection unit 260, the gaze state determination unit 270 is a gaze time that is a gaze stop time that is directed to the screen of the display unit 130, or a gaze number that is the number of gaze stops per predetermined time. Determine. In addition, it is good also as a structure which determines combining both gaze time and the frequency | count of gaze.

  The frame rate control unit 280 controls the frame rate of the guide video displayed on the screen of the display unit 130 based on the determination result of the gaze state determination unit 270. The display unit 130 displays the guidance video generated by the video superimposing unit 250 in the intersection guidance area.

  Next, operation | movement of the navigation apparatus 200 which concerns on embodiment of this invention is demonstrated using the flowchart of FIG.

  When the driver sets a route (step S401), the navigation device 200 acquires travel information (step S402). The travel information includes road map data stored in the map storage unit 210, current position information of the host vehicle acquired by the position acquisition unit 220, and a live-action image in front of the host vehicle acquired by the video acquisition unit 240.

  The navigation device 200 refers to the acquired travel information, and if the vehicle is not in the intersection guidance area and the guidance is finished, the processing is finished (steps 403 and 404). If the vehicle is not in the intersection guidance area and the guidance has not ended, travel information is acquired again (steps 403 to 402). On the other hand, if the vehicle is in the intersection guidance area, the process proceeds to guide video generation processing (steps 403 and 500).

  Hereinafter, the guide video generation processing step 500 will be described with reference to FIGS. FIG. 5 is a flowchart showing guide video generation processing. In this guide video generation process, the video superimposing unit 250 firstly captures the three-dimensional map stored in the map storage unit 210 and the imaging direction and imaging range of the video acquired by the guide video camera 110 of the video acquisition unit 240. Based on the camera position, camera angle (horizontal angle, elevation angle), focal length, and image size, which determine parameters, the viewing space of the camera in the three-dimensional map space is obtained (step S501).

  Here, the three-dimensional map is a map in which position information is represented by latitude coordinates, longitude coordinates, and altitude coordinates. The calculation of the visual field space of the camera is performed by a method as shown in FIG. 6, for example. In a three-dimensional map space, a point F that is advanced from the camera position (viewpoint) E by the focal length f in the camera angle direction is obtained, and a horizontal x vertical y plane (camera screen) corresponding to the image size is obtained from the viewpoint E and the point Set to be perpendicular to the vector connecting F.

  Next, a three-dimensional space formed by a half line connecting the viewpoint E to the four corner points of the camera screen is obtained. This three-dimensional space theoretically extends to infinity, but is censored at an appropriate distance from the viewpoint E, and is defined as a visual field space.

  It should be noted that a 2D map obtained by removing altitude information from a 3D map may be used instead of the 3D map, and the visual field space of the camera in the 2D map space may be obtained. The parameters for determining the imaging direction and the imaging range are not limited to those described above, and may be calculated using other parameters such as the angle of view as long as the imaging direction and the imaging range are determined.

  Next, the video superimposing unit 250 performs a road detection process for detecting a road and its position in the visual field space of the camera in the three-dimensional map space (step S502). FIG. 7 shows roads detected by the road detection process. FIG. 7 is a view of the three-dimensional map space and the camera view space as seen from above. In FIG. 7, the road surrounded by the visual field space is detected by the road detection process.

  Next, the video superimposing unit 250 arranges a guide object at a position on the road corresponding to the guide route searched by the route search unit 230 among the roads detected by the road detection process in the three-dimensional map space ( Step S503). FIG. 8 shows the arrangement position of the guidance object. Note that the shape of the guide object is not limited to the arrow graphic shown in FIG. 8, and for example, a polygonal line graphic obtained by removing the tip triangle from the arrow graphic may be used.

  Next, the video superimposing unit 250 performs projection conversion on the guidance object using the camera screen as a projection plane (step S504). In the projection processing, the projection plane onto which the guide object is projected matches the camera screen acquired by the guide video camera 110 of the video acquisition unit 240, so that the guide object is on the road (guide route) shown on the live-action video. (See FIG. 9). When superimposing a guidance object on a live-action video, the position of the road reflected in the camera is detected using a known image recognition technique such as white line detection or road edge detection, and the superimposition position of the guidance object is corrected. It doesn't matter if you do.

  As described above, when the guidance video generation process ends and the guidance video is displayed on the screen of the display unit 130, the gaze state determination unit 270 determines the gaze state of the driver directed to the screen of the display unit 130 ( Step S405). At this time, it is assumed that the gaze state determination unit 270 determines the gaze time as the gaze state.

  As the relationship between the gaze time and the frame rate in the graph of FIG. 10A is indicated by a continuous function, the frame rate control unit 270 is displayed on the screen of the display unit 130 as the gaze time increases. Control is performed to reduce the frame rate of the guide video (step S406). The display unit 130 displays the guide video on the screen at the frame rate controlled by the frame rate control unit 270 (step S407). Further, as shown by the step function of the relationship between the gaze time and the frame rate in the graph of FIG. 10B, the frame rate of the guide video displayed on the screen of the display unit 130 is increased as the gaze time increases. You may control to lower in steps.

  Note that the gaze situation determination unit 270 may be configured to determine the number of gazes per predetermined time as the gaze situation. In this case, the frame rate control unit 270 may be configured to control the frame rate of the guide video displayed on the screen of the display unit 130 as the number of gazes per predetermined time increases.

  The frame rate control unit 280 controls to reduce the frame rate when the road shape is a curve shape when the shape information of the road being traveled is acquired from the map storage unit 210 as the travel information. May be. Furthermore, the frame rate control unit 280 may be configured to control the frame rate in consideration of the type of the road when the type information of the road that is running is acquired as the running information from the map storage unit 210. . At this time, for example, as shown in FIG. 11, in the case of a narrow street with the lowest rank of road type, the frame rate is set to 15 fps. Also, if it is a main road with the next highest rank, the frame rate is 25 fps, and if it is the highest rank highway, the frame rate is 30 fps. In this manner, the frame rate may be controlled to decrease as the road type rank is lower.

  In this way, the frame rate of the guide video (moving image) displayed on the screen is controlled without instantaneously switching from the guide video (moving image) to the enlarged map (still image) based on the driver's gaze situation directed at the screen. To do. Therefore, it is possible to provide a navigation device that can perform the original navigation function of the guide video (moving image). It is also possible to avoid driving hazards caused by the driver gazing at the screen.

  In addition, as shown in FIG. 12, it is good also as a structure provided with the driving condition determination part 1200 which determines the driving condition of the own vehicle further. At this time, the frame rate control unit 280 may be configured to control the frame rate in consideration of an inter-vehicle distance between the host vehicle and the preceding vehicle, road congestion, or the like as a traveling state. In this case, as shown in the continuous function of the relationship between the inter-vehicle distance and the frame rate in the graph of FIG. 13, the frame rate may be controlled to decrease as the inter-vehicle distance decreases. Further, the frame rate control unit 280 may perform control so as to decrease the frame rate when the road is congested. In addition, what is necessary is just to use the sensing means of a well-known technique, for example, a millimeter wave sensor, an infrared sensor, for the measurement of the distance between the own vehicle and the vehicle ahead. Further, as the traveling state, the vehicle speed of the host vehicle may be further taken into consideration, and the frame rate may be controlled to decrease as the vehicle speed increases.

  As described above, the frame rate of the guide video (moving image) is controlled based on the traveling state of the host vehicle. Therefore, it is possible to provide a navigation device that can perform a navigation function faithful to the actual driving situation. For example, in a dangerous driving situation, by reducing the frame rate, it is possible to avoid driving danger caused by the driver gazing at the screen.

  In the above embodiment, the case where the frame rate is controlled based on the gaze situation and the case where the frame rate is controlled based on the running situation have been described. However, the frame rate is controlled based on at least the gaze situation. In addition, the frame rate may be controlled in consideration of the driving situation.

  As described above, according to the present invention, the degree of risk for driving is determined based on the time and frequency of gaze on the driver's screen, the type of road on which the driver is driving, the driving situation such as the inter-vehicle distance from the preceding vehicle, and the determination result. The frame rate is appropriately controlled based on the above. Specifically, when the degree of danger is high, the frame rate is reduced to maintain the merit of easy-to-understand navigation guidance using guidance video (video) and avoid it in situations where danger is expected It becomes possible to do. The degree of risk may be determined based on at least one factor of the time and frequency of watching the screen, the type of road, and the driving situation.

  The configuration described in the above embodiment is merely a specific example and does not limit the technical scope of the present invention. Any configuration can be employed within the scope of the effects of the present application.

  It is useful as mobile equipment such as car navigation.

The schematic diagram which shows the whole structure of the navigation apparatus which concerns on embodiment of this invention. The block diagram which shows the whole structure of the navigation apparatus which concerns on embodiment of this invention The figure which shows the structure of a gaze detection part. The flowchart which shows operation | movement of the navigation apparatus concerning embodiment of this invention. Flow chart showing guide video generation processing Schematic diagram showing the viewing space of the camera Schematic view of 3D map space and camera view space from above Schematic diagram showing the placement position of the guidance object Schematic diagram showing a guide video Diagram showing correspondence between gaze status and frame rate Diagram showing correspondence between rank of road type and frame rate The block diagram which shows the whole structure of the navigation apparatus which concerns on other embodiment of this invention. A diagram showing the correspondence between running conditions and frame rate

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Main apparatus 110 Guide image camera 120 Eye-gaze detection camera 130 Display part 200 Navigation apparatus 210 Map storage part 220 Position acquisition part 230 Path | route search part 240 Image acquisition part 250 Image superimposition part 260 Eye-gaze detection part 261 Pupil extraction part 262 Corneal reflection Image extraction unit 263 Focus determination unit 270 Gaze state determination unit 280 Frame rate control unit

Claims (10)

A navigation device that obtains a live-action image in front of the vehicle from the vicinity of the vehicle position to a guide point, and navigates using a guide image in which a guide object is superimposed on the acquired real-image image in front of the vehicle,
A display unit for displaying the guidance video;
A risk determination unit for determining the driving risk,
A navigation apparatus comprising: a frame rate control unit that controls a frame rate of a guide video displayed on the display unit based on a determination result of the risk determination unit.   The risk level determination unit includes a gaze status determination unit that determines a gaze status based on information about a user's line of sight directed to the guide video displayed by the display unit, and a frame rate control unit includes the gaze status determination unit The navigation device according to claim 1, wherein a frame rate of the guide video displayed by the display unit is controlled based on the determination result.   The navigation device according to claim 2, wherein the gaze state determination unit determines a gaze time, and the frame rate control unit decreases the frame rate when it is determined that the gaze time is long.   The gaze state determination unit determines the number of gazes per predetermined time, and the frame rate control unit lowers the frame rate when it is determined that the number of gazes per predetermined time is large. 3. The navigation device according to 2.   The risk determination unit includes a traveling state determination unit that determines a traveling state of the host vehicle, and the frame rate control unit is configured to display a guide video displayed on the display unit based on a determination result of the traveling state determination unit. The navigation apparatus according to claim 1, wherein the frame rate is controlled.   The traveling state determination unit determines whether or not the shape of the road on which the vehicle is traveling is a curved shape, and the frame rate control unit determines that the shape of the road on which the vehicle is traveling is a curved shape. The navigation device according to claim 5, wherein the frame rate is lowered.   The traveling state determination unit determines the rank of the type of road on which the vehicle is traveling, and the frame rate control unit determines the frame when the rank of the type of road on which the vehicle is traveling is low. The navigation device according to claim 5, wherein the rate is lowered.   The traveling state determination unit determines an inter-vehicle distance between the own vehicle and the preceding vehicle, and the frame rate control unit decreases the frame rate when it is determined that the inter-vehicle distance between the own vehicle and the preceding vehicle is small. The navigation device according to claim 5.   The traveling state determination unit determines whether the road on which the vehicle is traveling is congested, and the frame rate control unit determines the frame rate when the road on which the vehicle is traveling is congested. The navigation device according to claim 5, wherein the navigation device is lowered. The said travel condition determination part determines the vehicle speed of the own vehicle, and the said frame rate control part reduces a frame rate, when it determines with the vehicle speed of the own vehicle being large. Navigation device.

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