JP2006162442A - Navigation device and navigation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigation device for displaying guidance information such as an arrow superimposed on an actual scenery so as not to hinder driving.
A route creation unit creates a route based on own vehicle position information, map information, and destination position information acquired from a vehicle position acquisition unit, a map storage unit, and a destination setting unit. . The guide information specifying unit 5 specifies the position on the map for presenting the guide information and the type of the guide information to be presented. The obstacle detection unit 6 detects the position and type of an obstacle (pedestrian, vehicle, etc.) around the host vehicle by image recognition or the like. The priority determination part 7 determines the presentation priority of each obstacle. The display position determination unit 8 obtains a position that does not overlap the detected obstacle as the display position of the guidance information. The image output unit 9 outputs the guide information to a determined position in the windshield of the vehicle or to a determined position in the display that displays the front image.
[Selection] Figure 1

Description

  The present invention relates to a navigation apparatus, and more particularly to a navigation apparatus that guides a user by presenting guidance information on a real landscape.

  In recent years, in-vehicle navigation devices that guide users to their destinations using map images and sounds have become widespread. In navigation apparatuses that are currently popular, virtual images stored on a DVD or the like are used as map images and forward scenery images used for route guidance. Then, a user such as a driver confirms a direction to proceed by looking at a map image projected on a display installed in the vehicle.

  By the way, as an image used for route guidance, it has also been proposed to use a real landscape image taken in real time by a camera installed in the host vehicle instead of a virtual image (for example, Patent Document 1). When a real landscape image is used, an image obtained by superimposing guidance information such as an arrow indicating the traveling direction on the real landscape image is presented to the user as an image for route guidance.

Since the time that the driver can see the screen is limited, it is desirable that the image displayed on the display is an image that can immediately grasp the direction in which to proceed. If a real landscape image is used, the difference from the actual landscape is smaller than when a virtual landscape image is used. Therefore, there is an advantage that the driver can grasp the direction to proceed accurately in a short time.
JP-A-7-63572 (page 11, FIG. 11)

  By the way, when guidance information is presented on a real landscape image, pedestrians, traffic lights, etc. are also displayed in the image presented to the user, but these are taken into account in the conventional navigation device. Was not considered. However, if a pedestrian or traffic light is hidden behind the displayed guidance information, the driver's attention to the pedestrian or the like may be insufficient. Therefore, it is desirable to display guidance information in consideration of pedestrians and the like from the viewpoint of safety.

  In addition, since the brightness outside the vehicle changes depending on the weather and time zone, when an actual landscape image is used, there is a possibility that an image display that cannot be recognized by the user may be made unless these are taken into consideration.

  Therefore, an object of the present invention is to provide a navigation device that displays guidance information such as arrows on a real landscape so as not to hinder driving. Another object of the present invention is to provide a navigation device that displays guidance information that is easy for a user to recognize on a real landscape.

  In order to achieve the above object, a navigation device according to the present invention is a navigation device that guides a user based on guidance information displayed over a real landscape, and specifies guidance information to be presented from one or more pieces of guidance information. A guidance information specifying unit, an obstacle detection unit for specifying the position of an obstacle on the plane when the scenery in front of the host vehicle is planarly viewed, and an obstacle when the guidance information is displayed on the plane A display position determining unit that specifies a position with a small overlapping area, uses the specified position as a display position, and an image output unit that displays the guidance information at the display position.

  In addition, the navigation device of the present invention includes a map storage unit that stores a map, a vehicle position acquisition unit that acquires a vehicle position on the map, a destination setting unit that sets a destination on the map, a map, You may further provide the route creation part which produces a route based on the present location and the destination.

  The obstacle detection unit may include an imaging unit that captures a landscape image in front of the host vehicle and an image analysis unit that analyzes an image captured by the imaging unit and identifies an obstacle.

  In addition, the navigation device of the present invention further includes a priority determining unit that gives priority to be presented to the user to the guidance information specified by the guidance information specifying unit and each obstacle detected by the obstacle detecting unit. May be. At this time, a display position determination part makes a display position a position with little overlap area with an obstacle with a higher priority than guidance information.

  The display position determination unit may change the display method of the guidance information to a display method that improves the visibility of the obstacle when the guidance information and the obstacle overlap.

  More specifically, the display position determination unit may determine to change the shape of the guide information so that the overlapping area is reduced. Further, the display position determination unit may determine to hide the guide information at the display position.

  Further, the navigation device of the present invention includes a color determination unit that determines a color near the display position on a plane, and a color determination that determines that the color of the guidance information is different from the color determined by the color determination unit. May further be provided.

  The navigation device of the present invention further includes a light amount acquisition unit that acquires the amount of light incident from the front of the vehicle, and a luminance determination unit that determines the luminance of the guidance information based on the light amount acquired by the light amount acquisition unit. It may be.

  The image output unit may project and display the guidance information on the windshield of the own vehicle. Further, the image output unit may display guidance information superimposed on the actual landscape image displayed on the display.

  A navigation method according to the present invention is a navigation method that is executed by a navigation device that guides a user with guidance information that is displayed over a real scene, and specifies guidance information to be presented from one or more pieces of guidance information. A guidance information identification step, an obstacle detection step for identifying the position of the obstacle on the plane when the scenery in front of the vehicle is planarly viewed, and an obstacle when the guidance information is displayed on the plane You may provide the display position determination step which specifies a position with few overlap areas, and makes the said position a display position, and the image output step which displays guidance information on a display position.

  The navigation device according to the present invention can display guidance information on a real landscape so as not to hinder driving. That is, the navigation device according to the present invention detects obstacles that should not be overlooked by drivers such as pedestrians and traffic lights, and obstacles that give useful information to the driver such as lane signs and town name signs. Guidance information is displayed at a position that does not overlap with other obstacles. Therefore, the driver using the navigation device of the present invention can not only intuitively and accurately grasp the direction to proceed but can also drive in consideration of the surrounding safety.

  In addition, according to one aspect of the present invention, a priority order for presentation to a user is assigned to a detected obstacle. And the display position and display method of guidance information are determined so that the visibility of the obstacle with a higher priority than guidance information does not fall remarkably by displaying guidance information.

  According to still another aspect of the present invention, the color and brightness of the guidance information are determined based on the background color information and brightness information. Therefore, the displayed guidance information is easy for the user to recognize.

(First embodiment)
FIG. 1 is a configuration diagram of a navigation device according to the first embodiment of the present invention. The navigation device shown in FIG. 1 includes an own vehicle position acquisition unit 1, a map storage unit 2, a destination setting unit 3, a route creation unit 4, a guidance information identification unit 5, an obstacle detection unit 6, a priority determination unit 7, and a display. A position determination unit 8 and an image output unit 9 are provided.

  The own vehicle position acquisition unit 1 acquires the position information of the own vehicle and the posture (orientation / tilt) information of the own vehicle. Here, the position information is information on a place specified by longitude and latitude. The position information can be acquired by using, for example, GPS (Global Positioning System) or using a combination of a vehicle speed sensor and a gyro sensor. The posture information is information representing the direction (azimuth) and inclination of the own vehicle, and can be acquired by using a gyro sensor or the like.

  The accuracy of the position / posture information acquired by the vehicle position acquisition unit 1 may be as long as it is acquired by the vehicle position acquisition unit provided in a commonly used car navigation device. As a method for improving the accuracy of the position / posture information, for example, the position where the position of the vehicle obtained by the autonomous navigation is obtained by using the autonomous navigation that specifies the position of the own vehicle based on the information such as the vehicle speed and the inclination. There is a method of correcting with information.

  If RealTime Kinetic-GPS is used, the longitude and latitude coordinates can be obtained with higher accuracy. Further, when adopting autonomous navigation, if an optical gyro is used, it is possible to suppress a drift error peculiar to the gyro sensor, and an improvement in accuracy of posture information can be expected.

  The map storage unit 2 is a storage unit that stores digital map information and the like used in general navigation devices. Specifically, an HDD (Hard Disk Drive), a DVD (Digital Versatile Disk), or the like can be the map storage unit 2.

  The destination setting unit 3 is used when a user sets a destination. In order to realize this, the destination setting unit 3 only needs to include an input unit such as a pointing device, a keyboard, or a remote controller, and a display unit. More specifically, it is possible to acquire the history and latitude of the position on the map that is pointed to by the pointing device, or to receive or input the longitude and latitude obtained by accessing the Internet site by the user with a mobile phone or the like. What is necessary is just to have the structure.

  The route creation unit 4 uses the vehicle position / posture information, the map information, and the destination position information acquired from the vehicle position acquisition unit 1, the map storage unit 2, and the destination setting unit 3 from the current position to the destination. Create a route to the ground. As a method of creating a route, a generally known method such as Dijkstra method may be used.

  The guide information specifying unit 5 specifies a point where the guide information is presented or a point where processing is started to present the guide information. Moreover, the guidance information specific | specification part 5 also specifies the guidance information (image for route guidance) to show, when presenting either of several guidance information.

  The obstacle detection unit 6 detects pedestrians and traffic lights in the vicinity of the vehicle that the driver needs to pay attention to or needs to consider (hereinafter collectively referred to as obstacles). The position and type of the detected obstacle are specified, and the information (obstacle information) is created. Here, the position of the obstacle is a position on the plane when the scenery in front of the vehicle is viewed as a plane, that is, as a two-dimensional image. Specifically, the obstacle detection unit 6 receives a signal transmitted from a camera and an image processing device, an infrared radar device, a mobile phone terminal held by a pedestrian, or a transmitter attached to the obstacle. A machine is considered. The obstacle detection unit 6 may adopt any detection form as long as the position and the rough type of the obstacle can be specified.

  The priority determination unit 7 gives priority (priority order) according to the importance for the user to the guidance information and the obstacle specified by the guidance information specifying unit 5 and the obstacle detection unit 6 respectively. For example, obstacles that should not be overlooked by the driver, such as pedestrians and traffic lights, are given high priority, and low for cars that are traveling relatively far ahead or away from the vehicle. Priorities are assigned.

  The guidance information is a virtual object that is not recognized by the user until it is output from the image output unit 9, and the obstacle is a real object that exists in front of the user. In this way, the characteristics of guidance information and obstacles are different, but if priority is set in advance for all guidance information held by the navigation device and all detectable obstacles, With reference to the set priority, priority can be given to the guidance information to be presented and the detected obstacle.

  The display position determination unit 8 determines a position for displaying the guidance information based on the priority determined by the priority determination unit 7. In addition, the position here is a position on a plane when a landscape seen from the own vehicle is captured in a plane. At this time, a position for displaying the guidance information is selected so that an obstacle having a higher priority than the guidance information is not hidden behind the guidance information. Basically, the display position determination unit 8 determines to display the guidance information on a position where there is no obstacle or on an obstacle determined to have a lower priority than the guidance information. In addition, since there is no such position, when the guidance information has to be displayed on an obstacle with a high priority, the display position determination unit 8 is more than the case where the visibility of the guidance information is normally displayed. It is determined that the guidance display is performed by a display method that also improves.

  The image output unit 9 displays the guidance information at the position determined by the display position determination unit 8. Specific examples of the image output unit 9 include a combination of a projector and a screen, a display, and the like. Note that the navigation device may include not only an image output unit but also a speaker (audio output unit) that outputs guidance voice.

  It should be noted that all or one of the processes performed by each of the above-described units, in particular, the destination setting unit 3, the route creation unit 4, the guidance information identification unit 5, the obstacle detection unit 6, the priority determination unit 7, and the display position determination unit 8. The unit may be realized by a computer program.

  Next, taking a more specific device configuration of the navigation device according to the present embodiment as an example, details of processing performed in the navigation device will be described. A navigation apparatus 100 shown in FIG. 2 includes a vehicle position / posture detection unit 10, an HDD 20, a TFT liquid crystal display 35 (hereinafter referred to as a display 35) provided with a pointing device 30, a camera 40, an arithmetic processing unit 50, and a video projection unit 90. And a speaker 95.

  Here, correspondence between each unit shown in FIG. 2 and each unit shown in FIG. 1 will be described. The vehicle position / posture detection unit 10 shown in FIG. 2 corresponds to the own vehicle position acquisition unit 1 shown in FIG. The vehicle position / posture detection unit 10 includes a GPS reception unit 11 and a gyro sensor 12. The HDD 20 corresponds to the map storage unit 2 shown in FIG. The destination setting unit 3 shown in FIG. 1 is realized by the pointing device 30, the display 35, the HDD 20 storing map data, and the arithmetic processing unit 50. The obstacle detection unit 6 is realized by the camera 40 and the arithmetic processing unit 50. In addition to this, the arithmetic processing unit 50 also functions as the route creation unit 4, the guidance information identification unit 5, the priority determination unit 7, and the display position determination unit 8 shown in FIG. 1. The video projection unit 90 and the speaker 95 correspond to the image output unit 9 shown in FIG. The video projection unit 90 includes a projector 91 and a screen 92.

  In addition, as for the navigation apparatus 100, it is desirable for the structure to acquire a power supply from the own vehicle. For example, the navigation device 100 may be connected to an accessory power source so that the navigation device is in the operation mode when the vehicle engine is in the on state, and the power saving standby mode is in the off state.

  The arithmetic processing unit 50 includes a CPU 51, a ROM 52, and a RAM 53. The ROM 52 stores programs for performing processing such as image display position calibration, route creation processing, obstacle detection processing, priority determination processing, and guidance information display position determination processing.

  The HDD 20 stores map data. The minimum map data held by the HDD 20 may be road network information data necessary for route search processing, land information information data used when determining a destination, and place name information data.

  The HDD 20 also stores guide information template images. 3A to 3C are examples of a template image of guidance information, where FIG. 3A is guidance information 131 displayed when guiding a right turn, and FIG. 3B is guidance information displayed when guiding a left turn. 132 and (c) are guidance information 133 indicating the destination. When the guide information 131 or the guide information 132 is presented, the distance to the intersection may be numerically displayed near the information. The guidance information 133 is information presented when a destination exists within the user's field of view.

  In addition to the above, the HDD 20 also stores a priority table (see FIG. 10). Here, the priority table is a table in which guidance information and obstacle names and guidance information and obstacle priority are described.

  The video projection unit 90 includes a projector 91 for head up display (hereinafter referred to as HUD) and a rear projection screen 92 (hereinafter referred to as screen 92). As shown in FIG. 4, the projector 91 and the screen 92 are disposed inside the vehicle 101.

  The image output by the projector 91 is projected on the windshield 102 through the screen 92. At this time, the image reflected by the windshield 102 is recognized by the driver as a virtual image 130. The virtual image 130 appears to the user in a position in front of the windshield 102 at a position separated by a distance between the screen 92 and the windshield 102.

  The camera 40 is preferably fixed at the position of the user's eye line so that the photographed image and the scenery that the user is viewing substantially match. The camera 40 may be any camera such as a CCD camera or a CMOS camera that can analyze a captured image in units of pixels. If the camera 40 is used only for obstacle detection and the captured image is not touched by the user, that is, if it is not displayed on the display 35, the resolution of the camera 40 is the obstacle. It is enough if it can be specified.

  When the projector 91 projects the guide information 131 shown in FIG. 3A onto the screen 92, the camera 40 captures a landscape image on which the guide information 135 as shown in FIG. 5 is displayed. Further, the landscape shown in FIG. 5 is also a landscape that the user sees through the windshield 102. In FIG. 5, a town name signboard 140, a traffic light 141, a lane signboard 142, a road 143, and a building 144 are real objects. And the guidance information 135 which is a virtual image floats in front of these real things.

  If the HUD is used, the guidance information 135 can be displayed on the actual scenery in front of the user, as shown in FIG. 5, so the user can check the guidance information 135 without moving the line of sight, You can grasp the course. The HUD has been mainly used for airplanes and the like, but recently, a vehicle-mounted one that displays a vehicle speed or the like as a focus has become common.

  As long as the projector 91 can display the brightness of the guidance information 135 at about 2000 lm, a projector 91 that is currently used generally may be used. The brightness of the image changes depending on the distance between the projector 91 and the screen 92. That is, as the distance between the projector 91 and the screen 92 increases, the size of the image projected on the screen 92 increases and the brightness of the image decreases.

In general, the outdoor brightness during the day is known to be about 10,000 candelaper square meters (cd / m ² ), but the brightness outside the vehicle viewed from the inside of the vehicle is reduced by the dimming process applied to the windshield 102. Lower than this. Therefore, even if the guidance information 131 is projected on the windshield 102 with a luminance value of 1,800 (cd / m ² ) even during the day, the guidance information 135 can be sufficiently recognized.

  Next, the process performed by the navigation device 100 according to the present embodiment will be described more specifically with reference to the flowcharts of FIGS. 6 and 7 and FIG. When the navigation device 100 is activated, first, the vehicle position / posture detection unit 10 acquires position information and posture information (initial position / posture information) using the GPS receiving unit 11 and the gyro sensor 12 (step S11). . At this time, as the posture information, the posture information acquired when the engine was stopped last time may be used as it is, or the true direction may be obtained using a magnetic compass. The running posture information is obtained based on the amount of change from the initial value.

  Next, the image projection position is calibrated using the image projection unit 90 and the camera 40 (step S12). This calibration is performed in order to grasp from which position of the projector 91 the image projected from which position is seen and displayed. More specifically, the calibration is performed by taking an image projected by the projector 91 with the camera 40 and analyzing the taken image. A detailed example of the calibration method will be described later.

  When calibration is completed in step S12, a screen for destination setting is displayed on the display 35. Here, the destination setting screen is an address input screen or a map screen. The user uses the pointing device 30 to select a destination address from the prefecture name and city name displayed on the display 35, or to indicate the destination on the displayed map. Specify the longitude and latitude. The longitude and latitude of the specified destination are input to the arithmetic processing unit 50 and stored in the RAM 53.

  Next, the arithmetic processing unit 50 creates route information using the initial position / posture information acquired in step S11, the destination information set in step S13, and the map information held in the HDD 20 ( Step S14). Since a route creation method using the die clastra method or the like is generally used in current navigation apparatuses, the description thereof is omitted in this specification.

  Note that if the brightness of the front landscape is high, the visibility of the image projected from the image projection unit 90 is reduced. For example, in the evening, a route with weight added so as to select a route on which the western sun does not directly enter. May be selected.

  When the route is created, the arithmetic processing unit 50 identifies a point on which the guidance information on the created route is presented (hereinafter referred to as guidance information presentation point) by longitude and latitude (step S15). The specified longitude and latitude are stored in the RAM 53.

  More specifically, the arithmetic processing unit 50 compares the route information created in step S14 with the conditions of the guidance information presentation point, and specifies the latitude and longitude of the point that meets the condition for each condition. Here, the guidance information presentation points are points such as 700 m, 300 m, 100 m, and 10 m in front of intersections that turn right or left. Such conditions are stored in advance in the RAM 53 or the like. The guidance information presentation point data specified by the arithmetic processing unit 50 is stored in the RAM 53 or the like in association with the guidance information data presented at the point.

  When the guidance information presentation point is specified in step S15, the arithmetic processing unit 50 acquires current location information from the vehicle position / posture detection unit 10 (step S16), and the guidance in which the current vehicle position is determined in step S15. It is determined whether it is an information presentation point (step S17). If it is not the guidance information presentation point as a result of the determination (NO in step S17), the current location information is acquired again (step S16).

  On the other hand, when it is determined that the point is the guidance information presentation point (YES in step S17), the arithmetic processing unit 50 specifies the guidance information presented at the point (step S21 in FIG. 7). At this time, as shown in FIG. 8A, the CPU 51 writes information (name, keyword, etc.) regarding the guidance information to be presented in the object table of the RAM 53.

  Next, an obstacle detection process is performed (step S22). More specifically, first, a scene in front of the vehicle is photographed by the camera 40. Then, the photographed image is subjected to image processing by the arithmetic processing unit 50, and an obstacle such as a signal or a pedestrian in the image is detected. Further, when the obstacle is a car or a motorcycle, the approach speed is also measured. The CPU 51 writes information such as the name of the detected obstacle and the approach speed in the object table of the RAM 53 as shown in FIG. Note that the approach speed is obtained by, for example, extracting a vehicle or a motorcycle from an image acquired by the camera 40, and then measuring the distance to the vehicle by taking a stereo image of an area where the vehicle is present. It is obtained by calculating the change.

  As an image processing method performed in step S22, a method of specifying the type of an object by color information or pattern matching can be considered. For example, since the lane sign is blue and rectangular, it can be specified by using color information and pattern matching. When performing obstacle detection processing such as pattern matching, it is more dangerous for the user to miss an obstacle than to misrecognize an obstacle that is not an obstacle. It is desirable to set a parameter (threshold value) for detecting an object softly.

  Next, the arithmetic processing unit 50 performs priority determination processing (step S23), and then performs display position selection processing (step S24). Then, the projector 91 projects the guide information by the determined display method on the display position of the guide information determined by the priority determination process and the display position selection process (step S25). When the projection is completed, current position information is acquired (step S26), and it is determined whether or not the current location is the destination (step S27). If the destination has not been reached (NO in step S27), the process returns to step S17 in FIG. If the destination is reached (YES in step S27), the navigation device ends the route guidance.

  Details of the priority determination process in step S23 will be described with reference to the flowchart of FIG. 9 and FIGS.

  First, the CPU 51 assigns a priority to each object described in the object table of the RAM 53 (step S31 in FIG. 9). At this time, the priority table shown in FIG. 10 is referred to.

  In the priority table shown in FIG. 10, the name of the object, the approach speed, the priority, and supplementary information are described. Of the numerical values described in the priority column of the priority table, “0” indicates that the priority is the highest, and the higher the numerical value, the lower the priority.

  In the priority table shown in FIG. 10, the priority of guidance information is changed according to the distance to the intersection. For example, the guidance information provided at 300 m before the intersection is considered to be more useful to the user than the guidance information presented at 700 m before the intersection. Therefore, priority is given to the guidance information presented at 700 m before the intersection. The degree is “4”, and the priority of the guidance information displayed 300 m before the intersection is “3”.

  Since the importance of the obstacle may vary depending on the traveling place, the contents of the priority table shown in FIG. 10 and the high priority may be changed by the user.

  In the priority table shown in FIG. 10, when the obstacle is a vehicle, the priority is varied depending on the approach speed. This is because it is considered that the risk to the user differs depending on the relative speed with the own vehicle whether it is a vehicle traveling in the same direction on the same lane or a vehicle traveling in the opposite lane. . Therefore, in the priority table shown in FIG. 10, the priority is set higher for a vehicle having a lower relative speed.

  Note that it is also possible to set the priority in more detail using the supplementary information in the right end column of the priority table shown in FIG. For example, when a lane sign indicating a “right turn lane” is detected as an obstacle, the importance of the lane sign for the user differs depending on whether the vehicle turns right at an intersection ahead. Therefore, when a right turn is detected when a lane sign in a right turn lane is detected, a priority value that is one higher than the value described in the priority table may be written in the object table.

  FIG. 11A shows the object table after the priority is written. When the writing of the priority to the object table is completed, the arithmetic processing unit 50 next determines whether there is an obstacle having the same priority as the guidance information among the obstacles described in the object table. Judgment is made (step S32 in FIG. 9). If there is an obstacle with the same priority as the guidance information (YES in step S32), the arithmetic processing unit 50 sets the priority so that the priority of the corresponding obstacle is one higher than the current priority. The value is rewritten (step S34). For example, since the priority of the vehicle 1 shown in FIG. 11A is “3”, which is the same as the guidance information, the priority of the vehicle 1 in the object table is “2” as shown in FIG. 11B. To be rewritten.

  After all the obstacles having the same priority as the guidance information have been changed (step S33), or when no obstacle having the same priority as the guidance information has been present from the beginning (NO in step S32) ), The priority value described in the object table is set as the final value (step S34). In the object table shown in FIG. 11B in which the priorities after processing described above are described, the only obstacle with a priority lower than the priority of the guidance information is the town name signboard.

  As described above, after the priority determination process is performed, the display position selection process is performed. The display position selection process will be described with reference to the flowcharts of FIGS. 12 and 13 and FIG.

  First, the arithmetic processing unit 50 identifies an area where an important obstacle exists in an image captured by the camera for the obstacle detection process (hereinafter, referred to as an important obstacle existence area 150) (step S41 in FIG. 12). . Here, the important obstacle existence area 150 is a rectangular area surrounded by a broken line shown in FIG. 14, and an obstacle (important obstacle) determined to have a higher priority than the guidance information to be presented is completely displayed. It is an area included in A region where an obstacle having a lower priority than the guidance information to be presented is not included in the important obstacle existence region 150 as in the town name signboard 140 shown in FIG.

  Next, the arithmetic processing unit 50 reads out information on the guidance information to be displayed from the HDD 20 and specifies the size of the information (step S42). Here, the size of the guidance information is the length of the guidance information in the vertical and horizontal directions when normally displayed.

  Next, the arithmetic processing unit 50 searches for an area where the guide information can be displayed in a normal size (hereinafter referred to as a normal displayable area) (step S43). Specifically, for example, as shown in FIG. 14, the search window 160 of the size specified in step S42 is slid in order from the upper left of the screen, and the overlapping area of the search window 160 and the important obstacle region 150 is increased. It is conceivable to search for the smallest area and set the area where the overlapping area is 0 as the normal displayable area. Even when there is no region where the overlapping area is 0, the CPU 51 stores the position information of the region where the overlapping area is minimum in the RAM 53.

  If there is a normal displayable area in which the overlapping area is 0 (step S44), it is determined that the position is the guidance information display position (step S45). If there is no normal displayable area (NO in step S44), the priority of the guidance information is read from the object table, and it is determined whether the value is lower than a predetermined value (FIG. 13). Step S51).

  If it is determined that the priority of the guidance information is less than the predetermined value (YES in step S51), it is determined not to display the guidance information (step S52). For example, when the predetermined value is 2, guidance information presented at 300 m and 700 m before the intersections with priorities of 3 and 4 is not displayed. The predetermined value used for the determination may be changeable by the user. When it is determined not to present the guidance information, only voice guidance may be performed.

  If it is determined that the priority of the guide information is not less than the predetermined value (NO in step S51), the guide information is displayed in the region that is specified in step S43 and has the smallest overlap area with the search window 160. Processing for display is performed. For this purpose, first, it is determined whether or not the guide information can be transformed to the size of the area specified in step S43 (step S53).

  One method for transforming the normal size guide information shown in FIG. 15A is to simply reduce the vertical and horizontal directions of the image as shown in FIG. 15B. As another method, as shown in FIG. 15C, there is a method of changing the reduction ratio between the upper part and the lower part of the guidance information. This method is effective when only the upper part of the guidance information enters the obstacle area when displayed in a normal size.

  Deformation limit value information indicating the degree of deformation when deformed to a minimum size that can be identified is added to the image information of the guide information. In step S53, when the guidance information is reduced to the size of the area to be displayed, it is determined whether or not the deformation value exceeds the deformation limit value of the guidance information. If the deformation value does not exceed the deformation limit value, the arithmetic processing unit 50 determines that the deformation is possible (YES in Step S53), and determines the deformation of the guidance information (Step S54). On the other hand, when the deformation value exceeds the deformation limit value (NO in step S53), the arithmetic processing unit 50 determines to change the display method (step S56). If the guidance information to be displayed is a character, there is a high possibility that the guidance information will not be recognized due to the deformation. Therefore, the character information may be handled as information that cannot be deformed.

  The display method after the change may be a display method that improves the visibility as compared with the case of performing normal display. As a method of improving the visibility, for example, a method of shortening the display time than usual, blinking, or lightening the color of the guidance display can be considered.

  Next, an example of the image projection position calibration method in step S12 described above will be described with reference to FIGS. The image shown in FIG. 16A is an example of a test pattern used for calibration. In this test pattern 180, two corners located diagonally out of the four corners of the square are marked. Such a test pattern 180 is projected onto the windshield 102 from the projector 91 through the screen 92 as shown in FIG. The calibration is performed using an image projected by the projector 91 and an image obtained by photographing the projected image with the camera 40.

  The test pattern may be a test pattern 181 with four square corners as shown in FIG. 16B, or a grid-like test pattern 182 as shown in FIG. 16C. May be. When the test pattern 182 is used, if the colors of the grids are made different, it is possible to know the positions where the grids are projected without performing complicated calculations.

  18A and 18B show an image 183 projected by the projector 91 and an image 184 photographed by the camera 40 at that time. Data indicating the correspondence between the image position projected by the projector 91 and the captured image position is stored in the RAM 53 or the HDD 20. That is, the correspondence table is created so that the first pixel from the upper left shown in FIG. 18A corresponds to the first pixel from the upper left of the pixel portion of the camera 40 and the second pixel adjacent to the right. Remembered. The scale set by the calibration is used in obstacle detection processing (step 22 in FIG. 7), display position selection processing (step S24), and the like.

  If the installation position and orientation of the camera 40 and the projector 91 are not frequently changed, the calibration may be performed only once for a plurality of activations. When calibration accuracy is guaranteed, the amount of information processing and the amount of data to be stored may be reduced by handling a plurality of pixels as a unit.

  In the present embodiment, the case where the HUD is used for the video projection unit 90 has been described as an example. However, without using the HUD, an image obtained by superimposing the guidance information image on the front landscape image captured by the camera 40 is displayed on the display 35. May be displayed. If the navigation apparatus of the present invention is configured to be attached to a motorcycle and a helmet and the guidance information is displayed on the visor, the navigation apparatus can be used as a motorcycle navigation apparatus with a small amount of information provided.

  The navigation device according to the present embodiment is useful for obstacles that should not be overlooked by drivers such as pedestrians and traffic lights, and drivers such as lane signs and town name signs when displaying guidance information over a real landscape. Detect obstacles that give the correct information and determine their priority. And the display position and display method of guidance information are determined so that the visibility of the obstacle with a higher priority than guidance information does not fall remarkably by displaying guidance information. Therefore, the displayed guidance information does not hinder driving. Therefore, the driver using the navigation device according to the present embodiment can not only intuitively and accurately grasp the direction to travel, but can also drive in consideration of the safety of the surroundings.

(Second Embodiment)
FIG. 19 is a configuration diagram of a navigation device according to the second embodiment of the present invention. The navigation device according to the present embodiment is the same as the navigation device according to the first embodiment except for the vehicle exterior light amount acquisition unit 201, the saturation acquisition unit 202, and the luminance / saturation determination unit. 203 is added. Note that among the components of the navigation device described in this embodiment, the same components as those already described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The vehicle exterior light quantity acquisition unit 201 acquires brightness information of the scenery ahead of the host vehicle. The saturation acquisition unit 202
The saturation information in the vicinity of the area where the guide information determined by the display position determination unit 8 is displayed is acquired. The luminance / saturation determination unit 203 then displays the luminance and saturation of the guidance information to be displayed based on the luminance information acquired by the outside light amount acquisition unit 201 and the saturation information acquired by the saturation acquisition unit 202. And decide. The image output unit 9 displays the guidance information at the position determined by the display position determination unit 8 with the luminance and saturation determined by the luminance / saturation determination unit 203.

  Next, taking a more specific device configuration of the navigation device as an example, details of processing performed by the navigation device according to the present embodiment will be described. A navigation device 200 shown in FIG. 20 has a configuration in which a luminance measurement unit 210 is added to the navigation device described with reference to FIG. 2 in the first embodiment.

  Here, the correspondence between each unit shown in FIG. 20 and each unit shown in FIG. 19 will be briefly described. The luminance measurement unit 210 illustrated in FIG. 20 corresponds to the outside light amount acquisition unit 201 illustrated in FIG. The luminance measurement unit 210 is provided to measure the luminance of light incident from the front direction of the host vehicle. The saturation acquisition unit 202 and the luminance / saturation determination unit 203 illustrated in FIG. 19 are realized by a combination of the camera 40 and the arithmetic processing unit 50.

  FIG. 21 is a flowchart showing a part of the processing performed in the navigation device 200. In the navigation device 200, the processes shown in FIGS. 6 and 21 are performed. The process shown in FIG. 21 is obtained by adding the process of step S28 to the process shown in FIG. Details of the processing in step S28 will be described with reference to the flowchart of FIG. Of the processes described in FIG. 21, the same processes as those described with reference to FIG. 7 in the first embodiment are denoted by the same step numbers and description thereof is omitted.

  As described in the first embodiment, the position for displaying the guidance information is determined by the display position determination process in step S24 of FIG. After determining that the guidance information is to be displayed in the region 230 surrounded by the thick broken line on the vehicle forward landscape image shown in FIG. 23 by this processing, the CPU 51 measures the luminance outside the vehicle measured by the luminance measuring unit 210. Is acquired (step S61 in FIG. 22). The acquired luminance is stored in the RAM 53.

  Next, the arithmetic processing unit 50 acquires the color information of the area 230 that displays the guidance information or the area 240 that is slightly larger than the area that displays the guidance information in the image shown in FIG. 23 (step S62). . Note that it is only necessary to determine in advance whether the area for acquiring color information is the area 230 or the area 240.

  As a method for detecting color information, a method of obtaining an average of the saturations acquired by the respective pixels included in the region 230 or 240 can be considered. Any method may be used.

  Next, the arithmetic processing unit 50 determines the color of the guidance information to be displayed based on the acquired color information (step S63 in FIG. 22). For example, in the image shown in FIG. 23, it is assumed that a tree with green leaves is shown in the area 230 for displaying the guidance information, and the color of the area 230 specified in step S62 is green. If guidance information is displayed in this area in green, which is the same color as the background color, the user may not be able to recognize the guidance information. Accordingly, the arithmetic processing unit 50 determines the color of the guidance information in order to display the color of the guidance information in a color different from the color of the area 230. As a method for determining a color, a method of selecting a color having a distance of chromaticity using the CIE color system shown in FIG.

  In step S62, if only the color information outside the guide information 135 within the area 230 or 240 is obtained without obtaining the color information of the entire area 230 or 240, the color of the guide information. Can be made more easily recognizable.

  When the color is determined, the arithmetic processing unit 50 determines the brightness of the guidance information to be presented (step S64). At this time, the luminance value of the guidance information may be set so that the contrast ratio between the guidance information and the guidance information is an appropriate contrast ratio for the user. When an image is projected on the windshield using the HUD, the lowest luminance is the luminance of light incident on the windshield from the front. The highest luminance is the luminance of the white image projected by the projector. The arithmetic processing unit 50 determines the brightness of the projected image so that the contrast ratio between the light incident from the front and the projected image is greater than or equal to a predetermined value, preferably about 1:20.

  When the guidance information is displayed with the same brightness as that of a bright place outside the tunnel when passing through a dark place such as a tunnel, the guidance information is too bright and may hinder the user's driving. Further, if the guidance information is always displayed in the same color, the guidance information may be buried in the background. Since the navigation apparatus according to the present embodiment determines the color and brightness of the guidance information based on the background color information and the brightness information, the presented guidance information is easily recognized by the user.

  When HUD is used as the video projection unit 90, if a relationship between the projection output of the projector and the brightness of the projected image is obtained in advance, an output necessary for displaying at a desired brightness value is obtained. I understand. The luminance of the image may be measured using the luminance measuring unit 210, or may be obtained by calculation based on the projection output, the distance to the image projection position, and the reflectance of the projection destination (front glass). If the luminance measurement unit 210 is not provided, the luminance outside the vehicle may be obtained from an image captured by the camera 40.

  INDUSTRIAL APPLICABILITY The navigation device of the present invention is useful as a navigation device or the like mounted on a vehicle or the like that guides a user with guidance information displayed over a real landscape.

1 is a configuration diagram of a navigation device according to a first embodiment of the present invention. The figure which shows an example of the concrete apparatus structure of the navigation apparatus shown in FIG. Figure showing an example of guidance information The figure explaining the image projection method at the time of using HUD Landscape view in front of the vehicle when guidance information is displayed The flowchart which shows the process sequence performed with the navigation apparatus shown in FIG. Continuation of FIG. The figure which shows the object table where guidance information and the information of the obstacle are described Flow chart showing processing procedure of priority determination processing The figure which shows an example of a priority table The figure which shows the object table where priority is described Flow chart showing processing procedure of display position selection processing Continuation of FIG. The figure explaining the determination method of the display position of guidance information The figure which shows the modification of guidance information The figure which shows an example of the test pattern image for calibrating an image display position Diagram explaining how the test pattern is projected Diagram showing test pattern image to be projected and test pattern photographed by camera The conceptual diagram of the navigation apparatus which concerns on the 2nd Embodiment of this invention. The figure which showed an example of the concrete apparatus structure of the navigation apparatus shown in FIG. The flowchart which shows the process sequence performed with the navigation apparatus shown in FIG. Flowchart showing the procedure of guidance information display color / luminance determination processing The figure for demonstrating the method of determining the color of the guidance information to display CIE color system diagram

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Own vehicle position acquisition part 2 Map memory | storage part 3 Destination setting part 4 Route creation part 5 Guidance information specific part 6 Obstacle detection part 7 Priority determination part 8 Display position determination part 9 Image output part 201 Outside light quantity acquisition part 202 Aya Degree acquisition unit 203 Luminance / saturation determination unit

Claims (12)

A navigation device that guides a user with guidance information displayed over a real landscape,
A guide information specifying unit for specifying guide information to be presented from one or more guide information;
An obstacle detection unit for identifying the position of the obstacle on the plane when the scenery in front of the vehicle is captured in a plane,
A display position determination unit that identifies a position with a small overlapping area with the obstacle when the guidance information is displayed on the plane, and sets the position as a display position;
A navigation apparatus comprising: an image output unit that displays the guidance information at the display position. A map storage unit for storing a map;
A vehicle position acquisition unit for acquiring the vehicle position on the map;
A destination setting unit for setting a destination on the map;
The navigation apparatus according to claim 1, further comprising a route creation unit that creates a route based on the map, the vehicle position, and the destination. The obstacle detection unit is
A shooting unit for shooting landscape images in front of the vehicle;
The navigation apparatus according to claim 1, further comprising: an image analysis unit that analyzes an image captured by the imaging unit and identifies the obstacle. A priority determining unit that assigns a priority to be presented to the user to the guidance information identified by the guidance information identifying unit and each obstacle detected by the obstacle detection unit;
The navigation device according to claim 1, wherein the display position determination unit sets a position where an overlapping area with an obstacle having a higher priority than the guidance information is small as a display position.   The display position determination unit changes the display method of the guidance information to a display method that improves the visibility of the obstacle when the guidance information and the obstacle overlap at the display position. The navigation device according to claim 4.   The navigation device according to claim 5, wherein the display position determination unit determines to change the shape of the guide information so that an overlapping area between the guide information and the obstacle is reduced. .   The navigation device according to claim 5, wherein the display position determination unit determines to hide the guidance information. A color judgment unit for judging a color near the display position on the plane;
The navigation device according to claim 1, further comprising a color determination unit that determines that the color of the guidance information is a color different from the color determined by the color determination unit. A light amount acquisition unit for acquiring the amount of light incident from the front of the vehicle;
The navigation device according to claim 1, further comprising: a luminance determination unit that determines luminance of the guidance information based on the light amount acquired by the light amount acquisition unit.   The navigation apparatus according to claim 1, wherein the image output unit projects and displays the guidance information on a windshield of the vehicle.   The navigation apparatus according to claim 1, wherein the image output unit displays the guidance information in an overlapping manner on an actual scenery image displayed on a display. A navigation method that is executed by a navigation device that guides a user with guidance information that is displayed superimposed on a real landscape,
A guide information specifying step for specifying guide information to be presented from one or more guide information;
An obstacle detection step for identifying the position of the obstacle on the plane when the scenery ahead of the vehicle is captured in a plane;
A display position determining step of identifying a position with a small overlapping area with the obstacle when the guidance information is displayed on the plane, and setting the position as a display position;
An image output step of displaying the guidance information at the display position.

Images