JP2023038558A - Superimposed image display device - Google Patents

Abstract

To provide a superimposed image display device enabling an occupant to clearly recognize a road to exit from among a plurality of roads.SOLUTION: When there is a guide object spot to be a guide object ahead in a traveling direction of a vehicle, a guidance object for guiding a route of the vehicle at the guide object spot is displayed. While displaying the guidance object, the guidance object is displayed in a size in accordance with an angle made by an entrance direction in which the vehicle enters a guidance junction along the route of the vehicle and an exit direction in which the vehicle exits from the guidance junction along the route of the vehicle, and the smaller the angle is, the smaller the guidance object is displayed.SELECTED DRAWING: Figure 11

Description

The present invention relates to a superimposed image display device that assists driving of a vehicle.

2. Description of the Related Art Conventionally, various means have been used as information providing means for providing various types of information for assisting vehicle travel, such as route guidance and warnings of obstacles, to occupants of the vehicle. For example, it is the display by the liquid crystal display installed in the vehicle, the sound output from the speaker, or the like. In recent years, as one of such information providing means, there is a device that provides information by displaying an image superimposed on the surrounding environment (landscape, real scene) of the passenger. For example, a head-up display, a window shield display, or a method of displaying an image superimposed on a picked-up image of the surroundings of the vehicle displayed on a liquid crystal display.

Here, when the vehicle occupant is guided to the guidance target point by displaying the image superimposed on the surrounding environment, it is effective to superimpose the superimposed image on the vicinity of the guidance target point. be. The guidance target points include, for example, guidance junctions where vehicles turn left or right, features (facilities, signboards, etc.) that serve as landmarks of guidance junctions, and obstacles that require attention. For example, in Japanese Patent Application Laid-Open No. 2021-39085, when a vehicle approaches within a guidance start distance (300 m for general roads) with respect to a guidance junction, a captured image captured in front of the vehicle is displayed on the display, and the captured image A technique is disclosed for displaying images of multiple arrows indicating exit directions for guidance junctions along the path of the vehicle contained therein.

Japanese Patent Application Laid-Open No. 2021-39085 (Fig. 3)

In the technique described in Patent Document 1, the direction indicated by the arrow image indicates the exit direction of the vehicle at the guidance junction. For example, if an image of a leftward arrow is displayed, it indicates that the exit direction of the vehicle at the guidance junction is to the left. However, there are branch points where a plurality of roads are connected at close angles. , or the road 203 to exit.

The present invention has been made to solve the above-mentioned conventional problems. To provide a superimposed image display device which enables an occupant to clearly recognize a road to exit from among a plurality of roads.

In order to achieve the object, the superimposed image display device according to the present invention is a superimposed image display device that is mounted on a vehicle and allows a guide object that guides information to the occupants of the vehicle to be superimposed on the scenery around the vehicle and visually recognized. an object display means for displaying, along the route of the vehicle, the guide object for guiding the route of the vehicle at the guidance junction when there is a guidance junction ahead of the vehicle in the direction in which the vehicle travels; The display means displays the guide object in a size corresponding to an angle formed by an approach direction in which the vehicle enters the guidance junction on the route of the vehicle and an exit direction in which the vehicle exits the guidance junction on the route of the vehicle, The smaller the angle, the smaller the guidance object is displayed.
Note that the “landscape” includes not only a landscape (actual landscape) that is actually visually recognized from a vehicle, but also an image of the landscape, an image of the landscape, and the like.

According to the superimposed image display device of the present invention having the above-described configuration, in the case of displaying a guide object for guiding the route of the vehicle at the guidance junction along the route of the vehicle, the approach direction and the guidance for entering the guidance junction are displayed. The smaller the difference between the direction of exit from the branch point and the exit direction, the smaller the guidance object will be displayed. It is possible to make the occupant clearly recognize the road to be driven.

1 is a block diagram showing a navigation device according to a first embodiment; FIG. It is the figure which showed the junction|node data contained in map information. 4 is a flowchart of a driving support processing program according to the first embodiment; It is the figure which showed an example of the driving guidance screen displayed on a liquid crystal display. 10 is a flowchart of a sub-processing program of guidance object display position determination processing; FIG. 10 is a diagram showing a first guidance object; FIG. FIG. 10 is a diagram showing an example of arrangement of first guide objects; It is a figure explaining the calculation method of a retreat angle. FIG. 11 illustrates a second guide object; FIG. 11 is a diagram showing an example of arrangement of a second guide object; FIG. 4 is a diagram showing an example of a travel guidance screen displayed on a liquid crystal display as the vehicle travels; FIG. 10 is a schematic configuration diagram of a superimposed image display device according to a second embodiment; FIG. 10 is a diagram showing a display example of a guide object in the superimposed image display device according to the second embodiment; It is a figure showing about the problem of a prior art.

DETAILED DESCRIPTION OF THE INVENTION A first embodiment and a second embodiment in which a superimposed image display device according to the present invention is embodied in a navigation device will be described in detail below with reference to the drawings.

[First embodiment]
First, a schematic configuration of a navigation device 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a navigation device 1 according to the first embodiment.

As shown in FIG. 1, the navigation device 1 according to the first embodiment includes a current position detection unit 11 for detecting the current position of a vehicle in which the navigation device 1 is mounted, and a data recording unit 12 in which various data are recorded. , a navigation ECU 13 that performs various kinds of arithmetic processing based on input information, an operation unit 14 that receives operations from the user, a liquid crystal display 15 that displays a real scene image taken in front of the traveling direction to the user, Communication is performed between a speaker 16 that outputs voice guidance related to route guidance, a DVD drive 17 that reads a DVD as a storage medium, and an information center such as a probe center or a VICS (registered trademark: Vehicle Information and Communication System) center. and a communication module 18 . In addition, the navigation device 1 is connected to a front camera 19 and various sensors installed in the vehicle on which the navigation device 1 is mounted via an in-vehicle network such as CAN.

Each component of the navigation device 1 will be described in order below.
The current position detection unit 11 includes a GPS 21, a vehicle speed sensor 22, a steering sensor 23, a gyro sensor 24, etc., and is capable of detecting the current vehicle position, direction, vehicle speed, current time, and the like. . In particular, the vehicle speed sensor 22 is a sensor for detecting the moving distance and speed of the vehicle, generates a pulse according to the rotation of the driving wheels of the vehicle, and outputs the pulse signal to the navigation ECU 13 . The navigation ECU 13 then counts the generated pulses to calculate the rotational speed of the drive wheels and the travel distance. It should be noted that the navigation device 1 does not need to include all of the above four types of sensors, and the navigation device 1 may be configured to include only one or more of these sensors.

The data recording unit 12 also includes a hard disk (not shown) as an external storage device and recording medium, and a driver for reading the map information DB 31 and predetermined programs recorded in the hard disk and writing predetermined data to the hard disk. and a recording head (not shown). Note that the data recording unit 12 may be configured by a flash memory, a memory card, or an optical disk such as a CD or DVD instead of the hard disk. Alternatively, the map information DB 31 may be stored in an external server, and the navigation device 1 may acquire the information through communication.

Here, the map information DB 31 includes, for example, link data 32 relating to roads (links), node data 33 relating to node points, branch point data 34 relating to branch points, point data relating to points such as facilities, and map display for displaying maps. Data, search data for searching for routes, search data for searching for points, etc. are stored.

The link data 32 includes the width, slope, cant, bank, condition of the road surface, number of lanes on the road, locations where the number of lanes decreases, and width of the road to which each link of the road belongs. For corners, data representing the radius of curvature, intersections, T-junctions, corner entrances and exits, etc. For road attributes, data representing downhill roads, uphill roads, etc. Regarding the type, data representing highways and general roads (national roads, prefectural roads, narrow streets, etc.) are recorded respectively.

The node data 33 includes coordinates (positions) of actual road branch points (including intersections, T-junctions, etc.) and node points set at predetermined distances according to the radius of curvature of each road, A node attribute that indicates whether a node corresponds to an intersection, etc., a connection link number list that is a list of link numbers of links that connect to a node, and an adjacency that is a list of node numbers of nodes that are adjacent to a node via links. A node number list, data about the height (altitude) of each node point, and the like are recorded.

The branch point data 34 includes the intersection name of the branch point, the corresponding node information specifying the node forming the branch point, the connection link information specifying the link connected to the branch point, and the link connected to the branch point. The name of the corresponding area, information specifying the shape of the branch point, and the like are stored. Also stored is a structure that can serve as a landmark when performing right/left turn guidance at a branch point.

In addition to the number of roads connected to the intersection, the information specifying the shape of the branch point included in the branch point data 34 includes the direction in which each road is connected to the intersection. contains information that identifies the For example, as shown in FIG. 2, for an intersection where five roads 51 to 55 are connected, the angle θ1 of road 51, the angle θ2 of road 52, and the angle θ2 of road 53 with respect to one direction (for example, north direction) .theta.3, the angle .theta.4 of the road 54, and the angle .theta.5 of the road 55 are stored respectively.

On the other hand, a navigation ECU (electronic control unit) 13 is an electronic control unit that controls the entire navigation device 1, and includes a CPU 41 as an arithmetic device and a control device, and a working memory when the CPU 41 performs various arithmetic processing. In addition to the RAM 42 that stores the route data etc. when the route is searched, the ROM 43 that stores the driving support processing program (FIG. 3) etc. described later in addition to the control program, and the ROM 43 It has an internal storage device such as a flash memory 44 for storing programs. The navigation ECU 13 has various means as processing algorithms. For example, when there is a guidance junction ahead in the traveling direction of the vehicle, the object display means displays a guidance object that guides the vehicle at the guidance junction along the course of the vehicle.

The operation unit 14 is operated when inputting a departure point as a travel start point and a destination as a travel end point, and has a plurality of operation switches (not shown) such as various keys and buttons. Then, the navigation ECU 13 performs control to execute various corresponding operations based on switch signals output by pressing of each switch or the like. The operation unit 14 may have a touch panel provided on the front surface of the liquid crystal display 15 . Moreover, it is good also as a structure which has a microphone and a voice-recognition device.

The liquid crystal display 15 also displays a map image including roads, traffic information, operation guidance, operation menu, key guidance, guidance route from the departure point to the destination, guidance information along the guidance route, news, weather forecast, Time, mail, TV program, etc. are displayed. Further, particularly in the first embodiment, when the vehicle approaches a guidance branch point, the liquid crystal display 15 displays an image captured by the front camera 19, that is, the current scenery (real scene image) around the vehicle (especially in front of the vehicle). Furthermore, if necessary, the guide object is superimposed on the scenery and displayed.

Here, the guide object superimposed on the scenery and displayed includes information about the vehicle and various kinds of information used for assisting the driver in driving. For example, warnings to objects (other vehicles, pedestrians, guide signs) to be warned to passengers, guidance routes set in the navigation device 1, and guidance information based on the guidance routes (arrows indicating right and left turn directions, guidance branching directions, etc.) icon indicating a point mark, distance to a guidance junction, etc.), warnings displayed on the road surface (caution for rear-end collision, speed limit, etc.), lane markings in which the vehicle is traveling, current vehicle speed, shift position, remaining energy level, advertisement Images, facility information, guide signs, map images, traffic information, news, weather forecasts, times, screens of connected smartphones, etc. In the first embodiment described below, the guide object is guide information for providing guidance at a guide branch point ahead in the traveling direction of the vehicle. More specifically, an arrow indicating the exit direction of the guidance junction, a plurality of arrows arranged along the future course of the vehicle at the guidance junction, or the like.

In addition, the speaker 16 outputs voice guidance that guides the vehicle along the guidance route based on instructions from the navigation ECU 13 and traffic information guidance.

Also, the DVD drive 17 is a drive capable of reading data recorded on recording media such as DVDs and CDs. Then, based on the read data, music and video are reproduced, the map information DB 31 is updated, and so on. A card slot for reading and writing a memory card may be provided instead of the DVD drive 17 .

In addition, the communication module 18 is a communication device for receiving traffic information consisting of information such as congestion information, traffic regulation information, and traffic accident information transmitted from a traffic information center, such as a VICS center or a probe center. For example, mobile phones and DCMs correspond.

Further, the front camera 19 is an imaging device having a camera using a solid-state imaging device such as a CCD, for example. be. The captured image captured by the front camera 19 is displayed on the liquid crystal display 15 as the scenery (real scene image) around the vehicle (especially in front of the vehicle) as described above.

Next, a driving support processing program executed by the navigation ECU 13 in the navigation device 1 having the above configuration will be described with reference to FIG. FIG. 3 is a flow chart of a driving support processing program according to the first embodiment. Here, the driving support processing program is executed after the ACC power supply (accessory power supply) of the vehicle is turned on, and by making the guidance object superimposed on the scenery around the vehicle displayed on the liquid crystal display 15 visible, the vehicle can be driven. It is a program that provides support. 3 and 5 below are stored in the RAM 42 and ROM 43 provided in the navigation device 1, and are executed by the CPU 41. FIG.

In the following description, an example of performing vehicle travel guidance along a guidance route set by the navigation device 1 as vehicle travel assistance using a guide object will be described. The guidance objects to be displayed are guidance information for providing guidance at guidance junctions ahead of the vehicle in the direction of travel. A process for displaying a plurality of arrows arranged along a line as a guide object will be described as an example. However, the navigation device 1 can also provide guidance and information other than the above-described driving assistance using the guidance object. Also, the guide object to be displayed can be information other than the arrow. For example, as a guide object, there are warnings for objects to be warned to passengers (other vehicles, pedestrians, guide signs), warnings displayed on the road surface (caution for rear-end collision, speed limit, etc.), distance to the next guidance junction , current vehicle speed, shift position, remaining energy, advertisement image, facility information, guide signs, map image, traffic information, news, weather forecast, time, screen of connected smartphone, etc. can also be displayed.

First, in the driving support processing program, in step (hereinafter abbreviated as S) 1, the CPU 41 identifies the current position of the vehicle based on the detection result of the current position detector 11 and map information. Note that when specifying the current position of the vehicle, a map matching process for matching the current position of the vehicle with the map information is also performed. After that, the guidance route set in the navigation device 1 is read, and the distance from the specified current position of the vehicle to the next guidance junction along the guidance route is calculated. The guidance branch point is a branch point (intersection) at which the navigation device 1 performs guidance such as a right or left turn instruction when the navigation device 1 provides travel guidance according to the guidance route set in the navigation device 1 . A branch point (difficult intersection) that does not turn right or left but has a special shape also corresponds to a guidance branch point.

Next, in S2, the CPU 41 determines whether or not the distance to the next guidance junction calculated in S1 is less than a predetermined guidance start distance. The guidance start distance is determined according to the road type of the road on which the vehicle travels. However, the guidance start distance may be a variable value instead of a fixed value. For example, when there is another branch point within 200 m on the near side of the guidance branch point on a general road, the distance from the guidance branch point to the other branch point may be used.

If it is determined that the distance to the next guidance branch point calculated in S1 is less than the guidance start distance (S2: YES), the process proceeds to S3. On the other hand, if it is determined that the distance to the next guidance branch point calculated in S1 is not less than the guidance start distance (S2: NO), the process returns to S1.

In S3, the CPU 41 acquires the coordinates of a point to be guided by the guide object, that is, a point on which the guide object should be superimposed (arranged) (hereinafter referred to as a guide point). In the first embodiment, the guide objects are used to provide right/left turn guidance at the guidance junction. It does, and therefore the coordinates of the guidance point correspond to the coordinates of the guidance junction. Although the coordinates of the guidance branch point are specified from the map information possessed by the navigation device 1, they may be specified by performing image recognition processing on the image captured by the front camera 19. FIG.

Next, in S4, the CPU 41 performs guide object display position determination processing (FIG. 5), which will be described later. The guide object display position determination process is based on the current position of the vehicle and the coordinates of the guide point acquired in S3, and determines the size and shape of the guide object to be displayed on the liquid crystal display 15 and the position ( range) is specifically determined. The size, shape, and display position of the guide object determined in S4 are conditions for superimposing the guide object on, for example, a guide point in the scenery or in the vicinity thereof so that the passenger can see the guide object. However, depending on the current position of the vehicle and the type of the guide object, the guide object may be visually superimposed on the guide point or its surroundings in the scenery.

Subsequently, in S5, the CPU 41 generates an image of the guidance object having the size and shape determined in S4, further transmits a control signal to the liquid crystal display 15, and displays the generated guidance to the liquid crystal display 15. An image of the object is drawn at the position (range) determined in S4. The liquid crystal display 15 displays an image captured by the front camera 19 in advance before the distance from the vehicle to the guidance branch point becomes less than the guidance start distance, that is, the scenery around the vehicle (especially in front of the vehicle) at the current time (actual image). is displayed. As a result, it is possible for the vehicle occupant to visually recognize the guide object superimposed on the scenery.

FIG. 4 is a diagram showing an example of the travel guidance screen 61 displayed on the liquid crystal display 15 in S5. As shown in FIG. 4, the liquid crystal display 15 displays a current scene 62 in front of the vehicle captured by the front camera 19 . Then, the image of the guide object is displayed superimposed on the scenery 62 in front of the vehicle.

Here, in the first embodiment, there are a plurality of types of guidance objects as guidance objects used for guidance, and one or a plurality of types of guidance objects selected according to the content of guidance and the current situation are displayed. In addition, there are cases where multiple types of guide objects are to be displayed at the same time. For example, the example shown in FIG. 4 is an example of the travel guidance screen 61 displayed when the current position of the vehicle is close to the guidance junction within a predetermined distance (for example, 40 m). A first guide object image 63 made up of an arrow indicating a name and a second guide object image 64 made up of a plurality of arrows arranged along the future course of the vehicle at the guidance junction are displayed at the same time. .

The image 63 of the first guide object is superimposed and displayed at a position (higher than the line of sight of the vehicle occupant) a predetermined distance (for example, 3 m) from the road surface of the guide junction in the landscape 62. be done.

On the other hand, the image 64 of the second guide object is superimposed and displayed at a position (the line of sight of the vehicle occupant) above the road surface of the guide junction in the landscape 62 by a predetermined distance (for example, 1 m). . The second guide object image 64 includes a plurality of arrow-shaped object images, and the plurality of object images are displayed so as to be positioned at predetermined intervals along the future course of the vehicle at the guidance junction. . The direction of each arrow indicates the traveling direction of the vehicle at the guidance junction. As will be described later, the image 64 of the second guide object has a size corresponding to the angle formed by the direction of entry into the guidance junction on the course of the vehicle and the exit direction of exiting the guidance junction on the course of the vehicle. is displayed. More specifically, the smaller the angle formed by the approach direction and the exit direction (that is, the closer the exit direction is to the approach direction), the smaller the image 64 of the second guide object located farther from the vehicle. indicate. Details will be described later.

In addition to the arrow indicating the exit direction of the vehicle at the guidance junction, the name of the intersection, and the arrow indicating the future course of the vehicle at the guidance junction, the guidance object may also include an image indicating the distance to the guidance junction. may be superimposed on and displayed. The position where the image indicating the distance to the guidance junction is superimposed is, for example, the road surface immediately in front of the vehicle, and the distance from the vehicle to the guidance junction is within a predetermined distance section (for example, 200 m to 60 m on a general road). indicate.

After that, in S6, the CPU 41 determines whether or not the vehicle has passed through the guidance junction. For example, determination is made based on the current position of the vehicle detected by the current position detection unit 11 and map information.

When it is determined that the vehicle has passed through the guidance junction (S6: YES), a control signal is transmitted to the liquid crystal display 15 to hide the guidance object displayed on the liquid crystal display 15. (S7). The captured image captured by the front camera 19, that is, the scenery around the vehicle (particularly in front of the vehicle) at the present time (actual scene image) is continuously displayed for a certain period of time after that, and then switched to the display of the map image.

On the other hand, if it is determined that the vehicle has not passed through the guidance junction (S6: NO), the process returns to S4 to continue displaying the guidance object.

Next, sub-processing of the guidance object display position determination processing executed in S4 will be described with reference to FIG. FIG. 5 is a flow chart of a sub-processing program of guidance object display position determination processing.

First, in S11, the CPU 41 generates a three-dimensional space corresponding to the vicinity of the current position of the vehicle (especially forward in the direction of travel of the vehicle). In addition to roads, buildings, road signs, and the like may also be modeled in the three-dimensional space, or only roads may be modeled. Alternatively, the road may be simply a blank three-dimensional space with only the ground without modeling. Alternatively, the three-dimensional space may be stored in advance in the map information DB 31 as three-dimensional map information, and the three-dimensional map information around the corresponding vehicle position may be read from the map information DB 31 in S11. Also, a three-dimensional space may be generated based on an image captured by the front camera 19 . For example, by performing point group matching on an image captured by the front camera 19, it is possible to detect roads and structures around the roads and generate a three-dimensional space.

In S11, the CPU 41 also identifies the current position and orientation of the own vehicle in the generated three-dimensional space based on the parameters detected by the current position detection section 11. FIG. In particular, the position of the front camera 19 installed on the vehicle is the current position of the vehicle, and the direction of the optical axis of the front camera 19 is the azimuth of the vehicle. The position of the front camera 19 corresponds to the position of the vehicle occupant, and the optical axis direction of the front camera 19 corresponds to the line of sight of the vehicle occupant. Further, in S11, the position of the guidance branch point ahead of the vehicle in the traveling direction in the generated three-dimensional space is also specified.

Next, in S12, the CPU 41 generates the first guide object 65 as a guide object to be displayed. It should be noted that the first guide object 65 is, as shown in FIG. 6, an arrow indicating the exit direction of the guide junction. The size is set to 2m in length and 4m in width. Also, the intersection name is drawn inside the arrow. Also, assume that the guide object is a two-dimensional polygon and basically has no thickness. However, a thick three-dimensional polygon may be used. Also, the shape of the first guide object 65 generated in S12 can be changed as appropriate, and any shape other than the arrow may be used as long as it can indicate the exit direction at the guide junction.

Further, at S12, the CPU 41 arranges the generated first guide object 65 in the three-dimensional space generated at S11. The position where the first guide object 65 is arranged in the three-dimensional space is located near the center of the guidance junction 66 as shown in FIG. are arranged as follows. Therefore, when turning right at a guidance junction, the arrow points to the right when viewed from the vehicle, and when turning left at the guidance junction, the arrow points to the left when viewed from the vehicle. In addition, when turning right or left in a direction other than the right-angled direction, the arrow is slanted in an oblique direction. In addition, the height of placement is set to a position above the road surface by a predetermined distance (for example, 3 m) (a position higher than the line of sight of the vehicle occupant). After that, the process proceeds to S13.

In S13, the CPU 41 reads out the branch point data 34 stored in the map information and the guidance route set in the navigation device 1, and determines the approach road to enter the guidance branch point when the vehicle travels along the guidance route and the guidance route. Each exit road exiting from the junction is identified.

Next, in S14, the CPU 41 calculates an angle (hereinafter referred to as an exit angle) between the direction of entry into the guidance junction on the route of the vehicle and the direction of exit from the guidance junction on the route of the vehicle. The "entry direction" is the direction in which the vehicle travels on the approach road, and the "leaving direction" is the direction in which the vehicle travels on the exit road. That is, as shown in FIG. 8, when the vehicle enters the guidance branch point 66 from the approach road 71 and exits from the exit road 72 diagonally forward to the right, the exit angle extends the approach road 71. be the angle θ between the line and the exit road 72 . The branch point data 34 stores the connection angle of each road connected to the branch point as shown in FIG.

Subsequently, in S15, the CPU 41 calculates the minimum magnification of the second guide object 70 based on the exit angle calculated in S14. Specifically, it is calculated by the following formula (1).
Minimum magnification = 1 - (90 degrees - exit angle) x 0.0075 (1)

Therefore, when the exit angle is 90 degrees, that is, when the crossing intersection is the guide branch point, the minimum magnification is "1". The smaller the exit angle (that is, the closer the exit direction is to the approach direction), the smaller the minimum magnification. If the exit angle is greater than 90 degrees, the calculation is performed assuming that the exit angle is 90 degrees, and the minimum magnification is set to "1".

As will be described later, the second guide object 70 includes a plurality of substantially triangular objects arranged along the route of the vehicle, and when the exit angle is less than 90 degrees (that is, the minimum magnification is less than "1") For , the smaller the size of the object, the farther it is placed from the vehicle. Then, the minimum magnification calculated in S15 is the object placed closest to the vehicle (that is, the largest object) among the plurality of objects included in the second guide object 70, and the object located farthest from the vehicle. The size ratio of the placed object (ie the smallest object). When the minimum magnification is "1", all the objects included in the second guide object 70 have the same size, so the following processing of S16 is omitted.

In S16, the CPU 41 individually determines the magnification of each object included in the second guide object 70 based on the minimum magnification calculated in S15. The "magnification" is the size ratio of each object to the object located closest to the vehicle (that is, the largest object). Specifically, the magnification of each object is set so that the farther the object is placed from the vehicle at a certain ratio, the smaller the size of the object. so that For example, if the minimum magnification is 0.73 and there are 10 objects as shown in FIG. ", "0.91", "0.88", "0.85", "0.82", "0.79", "0.76", "0.73 (minimum magnification)".

Subsequently, in S17, the CPU 41 generates a second guide object 70 as a guide object to be displayed. The second guide objects 70 are, as shown in FIG. 9, a plurality of arrows having an isosceles triangle shape indicating the course of the vehicle at the guide junction. The standard size is set to 2m in length and 2m in width. When the exit angle is 90 degrees or more (i.e., the minimum magnification is "1"), all the arrows are set to the standard size, while the exit angle is less than 90 degrees (i.e., the minimum magnification is less than "1"). , the arrow located closest to the vehicle is of the standard size, and the other arrows are of the size obtained by multiplying the standard size by the magnification calculated in S16. Also, assume that the guide object is a two-dimensional polygon and basically has no thickness. However, a thick three-dimensional polygon may be used. Also, the shape of the second guide object 70 generated in S17 can be changed as appropriate, and may be any shape other than the arrow as long as it can indicate the course of the vehicle at the guide junction.

Further, at S17, the CPU 41 arranges the generated second guide object 70 in the three-dimensional space generated at S11. The positions where the second guide objects 70 are arranged in the three-dimensional space are arranged at predetermined intervals (for example, 1 m intervals) along the course of the vehicle at the guidance junction 66 as shown in FIG. More specifically, they are arranged in an arc shape at predetermined intervals from the entrance road of the vehicle when passing through the guidance junction to the exit road. The positions of the approach road and the exit road in the three-dimensional space are specified from the map information and the guidance route of the vehicle. Also, the direction of each arrow indicates the traveling direction of the vehicle at the guidance junction. The number and arrangement intervals of the second guide objects 70 can be set as appropriate. The second guide object 70 is desirably arranged not in the center of the vehicle's course but outside the center (for example, outside by 1/2 lane) in order to improve the visibility of the occupants. In addition, the height of the arrangement is set to a position above the road surface by a predetermined distance (for example, 1 m) (the position of the line of sight of the occupant of the vehicle). After that, the process proceeds to S18.

In S18, the CPU 41 determines the traveling direction of the vehicle from the current position of the vehicle and the height of the front camera 19 in the three-dimensional space where the first guide object 65 and the second guide object 70 are arranged in S12 and S17. The size and shape of the first guide object 65 and the second guide object 70 that can be visually recognized when visually recognized are stored as the size and shape of the guide object to be displayed on the liquid crystal display 15 . Here, the size and shape of the guide objects stored in S18 are used to set the first guide object 65 and the second guide object 70 arranged in the three-dimensional space to the current vehicle (more precisely, the front camera 19). ) are the size and shape of the first guide object 65 and the second guide object 70 that can be visually recognized when viewed from the viewpoint of ).

Thereafter, in S19, the CPU 41 estimates the position of the guidance junction in the landscape 62 displayed on the liquid crystal display 15 based on the current position of the vehicle and the position of the guidance junction in the three-dimensional space generated in S11. , the center of the position of the estimated guidance junction and a predetermined distance (for example, 3 m) above the road surface is determined as the position where the first guidance object 65 is to be displayed on the liquid crystal display 15 .

Furthermore, in S19, the CPU 41 estimates the position of the guidance junction in the scenery 62 displayed on the liquid crystal display 15 based on the current position of the vehicle and the position of the guidance junction in the three-dimensional space generated in S11, A second guidance object is displayed on the liquid crystal display 15 at a position along the route of the vehicle at the guidance junction shown in FIG. Determine the position where 70 is to be displayed.

After that, the process proceeds to S5, in which an image of the guide object having the size and shape determined in S18 is generated, a control signal is transmitted to the liquid crystal display 15, and the generated guide object image is drawn at the position (range) determined in S19.

As a result, the travel guidance screen 61 displayed on the liquid crystal display 15 as the vehicle travels becomes a screen as shown in FIG. Here, the image 64 of the second guide object is composed of a plurality of substantially triangular images, which are visually recognized in a state of being arranged along the course of the vehicle at the guide junction. This suggests to the occupant the future course of the vehicle at the guidance junction ahead in the direction of travel. As described above, the size of the image 64 of the second guide object is determined by the angle (exit angle ), and the size of the image 64 of the second guidance object makes the course of the vehicle at the guidance junction (more specifically, the exit road at the guidance junction) more clear. For example, as shown in FIG. 11, the image 64 of the second guide object is displayed by changing the size step by step so that the farther the object is from the vehicle, the smaller it becomes. When the exit angle is less than 90 degrees, an object located far from the vehicle is displayed smaller than when the exit angle is 90 degrees. When the exit angle is 90 degrees, the size of each object placed is the same regardless of the distance from the vehicle as described above, but the size of the displayed image of the object is the same as that of the vehicle. Since the size is set to be visible from the current position (S18), an object placed in the distance is displayed smaller than an object placed in front. When the exit angle is less than 90 degrees, as described above, the farther the object is from the vehicle, the smaller the size of the object itself. . As a result, when the size of an object located farther away than in front of the vehicle suddenly becomes smaller, the occupant can visually recognize that the road on which the object is placed and which should be exited is farther back. Therefore, even at a guidance branch point where a plurality of roads are connected at close angles, it is possible for the occupant to clearly recognize the road to exit from among the plurality of roads.

Thereafter, after the vehicle enters the guidance junction, the guidance object images 63 and 64 gradually become larger as the vehicle passes through the guidance junction. In addition, the images of the guide objects that are positioned behind the current position of the vehicle as the vehicle moves are hidden in order, and the images 63 and 64 of the guide objects are displayed at the timing when the vehicle completes passing through the guidance junction. disappears from the liquid crystal display 15 (S7).

As described in detail above, according to the navigation device 1 according to the first embodiment and the computer program executed by the navigation device 1, when there is a guidance target point to be guided in front of the vehicle in the direction of travel, A guidance object for guiding the route of the vehicle at the point is displayed (S5). The guide object is displayed in a size corresponding to the angle formed with the exit direction, and the smaller the angle, the smaller the guide object is displayed (S15 to S17). It is possible to make the occupant clearly recognize the road to exit from among a plurality of roads even at a branch point.
Also, since the guide object includes a plurality of objects arranged at predetermined intervals along the route of the vehicle, it is possible for the occupant to clearly recognize the road to exit from by arranging the plurality of objects.
In addition, among the plurality of objects, the size of the object farthest from the vehicle is determined according to the angle formed by the direction of entry and the direction of exit. Since the objects are displayed with their sizes changed step by step, it is possible for the occupant to visually grasp the road to exit from by the displacement of the sizes of the objects arranged along the route. For example, if the size of an object located in the distance suddenly becomes smaller than that in the foreground, it can be understood that the road on which the object is placed and which should be exited is further away on the far side.
Also, when there is a guidance junction within a predetermined distance ahead of the vehicle in the direction of travel, a guidance object that guides the vehicle at the guidance junction is displayed. can be clearly recognized by the occupant.
If the angle formed by the direction of entry and the direction of exit is less than 90 degrees, the guide object is displayed with a size corresponding to the angle. , displays the guide object in the size when the angle is 90 degrees, so the size of the object located near the vehicle and the object located far away are reversed, and the course of the vehicle becomes difficult to understand. can be prevented.

[Second embodiment]
Next, a superimposed image display device according to a second embodiment will be described with reference to FIGS. 12 and 13. FIG. In the following description, the same reference numerals as in the configuration of the superimposed image display device according to the first embodiment shown in FIGS. is shown.

The schematic configuration of the superimposed image display device according to the second embodiment is substantially the same as that of the superimposed image display device according to the first embodiment. Also, various control processes are substantially the same as those of the superimposed image display apparatus according to the first embodiment.
However, the superimposed image display device according to the first embodiment displays the captured image captured by the front camera 19 on the liquid crystal display 15 of the navigation device 1, and displays the guidance object on the liquid crystal display 15. In contrast to the superimposed image display apparatus according to the second embodiment, a head-up display system is used as means for displaying an image superimposed on the scenery around the vehicle. different in

A schematic configuration of the superimposed image display device according to the second embodiment will be described below with reference to FIG. 12 . FIG. 12 is a schematic configuration diagram of a superimposed image display device 101 according to the second embodiment.
As shown in FIG. 12 , the superimposed image display device 101 basically has a navigation device 103 mounted on a vehicle 102 and a front display 104 also mounted on the vehicle 102 and connected to the navigation device 103 . The front display 104 functions as a head-up display together with the windshield 105 of the vehicle 102 and serves as information providing means for providing various information to the occupant 106 of the vehicle 102 .

Here, the front display 104 is a liquid crystal display installed inside the dashboard 107 of the vehicle 102 and having a function of displaying an image on an image display surface provided on the front surface. CCFLs (cold cathode tubes) and white LEDs, for example, are used as backlights. As the front display 104, in addition to the liquid crystal display, an organic EL display or a combination of a liquid crystal projector and a screen may be used.

The front display 104 functions as a head-up display together with the windshield 105 of the vehicle 102, and the image output from the front display 104 is reflected on the windshield 105 in front of the driver's seat so that the occupant 106 of the vehicle 102 can see it. is configured as A guide object is displayed on the front display 104 as necessary. In the second embodiment described below, the guidance object is guidance information for guidance at a guidance branch point ahead of the vehicle in the direction of travel, as in the first embodiment. More specifically, an arrow indicating the exit direction of the guidance junction, a plurality of arrows arranged along the future course of the vehicle at the guidance junction, or the like.

In addition, when the occupant 106 visually recognizes the image displayed on the front display 104 by reflecting off the windshield 105 , the occupant 106 sees the front display at a distant position beyond the windshield 105 rather than at the position of the windshield 105 . The image displayed on 104 is configured to be viewed as a virtual image 110 . In addition, the virtual image 110 is superimposed and displayed on the surrounding environment (landscape, real scene) in front of the vehicle. It is also possible to display

Here, the position where the virtual image 110 is generated, more specifically, the distance L from the occupant 106 to the virtual image 110 (hereinafter referred to as imaging distance) is determined by the position of the front display 104 . For example, the imaging distance L is determined by the distance (optical path length) along the optical path from the position where the image is displayed on the front display 104 to the windshield 105 . For example, the optical path length is set so that the imaging distance L is 1.5 m.

A front camera 111 is installed above the front bumper of the vehicle, behind the rearview mirror, or the like. The front camera 111 is, for example, an imaging device having a camera using a solid-state imaging device such as a CCD, and is installed with the optical axis directed forward in the traveling direction of the vehicle. Then, by performing image processing on the captured image captured by the front camera 111, the situation of the forward environment (that is, the environment where the virtual image 110 is superimposed) viewed by the passenger 106 through the windshield is detected. be. A sensor such as a millimeter wave radar may be used instead of the front camera 111 .

In addition, an in-vehicle camera 112 is installed on the upper surface of the instrument panel of the vehicle. The in-vehicle camera 112 is, for example, an imaging device having a camera using a solid-state imaging device such as a CCD, and is installed with its optical axis directed toward the driver's seat. A detection range (imaging range of the in-vehicle camera 112) in which the passenger's face is generally expected to be located in the vehicle is set, and the face of the passenger 106 sitting in the driver's seat is imaged. Then, by performing image processing on the captured image captured by the in-vehicle camera 112, the eye position (line-of-sight starting point) and line-of-sight direction of the occupant 106 are detected.

Then, the superimposed image display device according to the second embodiment displays the guide object image 120 on the front display 104 as shown in FIG. 13 in S5 of the above-described driving support processing program (FIG. 3). As a result, a virtual image 121 of the guide object image 120 is superimposed on the scenery through the windshield 105 by recognizing the guide object image 120 displayed on the front display 104 as shown in FIG. visible.

As a result, as in the superimposed image display device according to the first embodiment, it is possible to accurately ascertain the position of the guidance junction at which the vehicle is to turn left or right and the direction of exit at the guidance junction. In the superimposed image display apparatus according to the second embodiment, the size and shape of the guide object to be displayed on the front display 104 and the position (range) to display the guide object are determined in the guide object display position determination process of S4. to decide. Moreover, it is desirable that the current position and direction of the own vehicle specified in the three-dimensional space in S11 are the position of the vehicle occupant and the line-of-sight direction of the occupant detected using the in-vehicle camera 112 .

It should be noted that the present invention is not limited to the above-described embodiments, and of course various improvements and modifications are possible without departing from the gist of the present invention.
For example, as means for displaying an image superimposed on the scenery around the vehicle, the first embodiment uses the liquid crystal display 15 displaying the actual scene image, and the second embodiment uses a head-up display system. On the other hand, a window shield display (WSD) for displaying images may be used. In WSD, the front glass may be used as a screen to display an image from a projector, or the front glass may be used as a transmissive liquid crystal display. The image displayed on the windshield by WSD is an image superimposed on the scenery around the vehicle.

Further, in the first and second embodiments, the guide objects are the first guide object 65, which is an arrow indicating the exit direction of the vehicle at the guidance junction ahead of the vehicle in the direction of travel, and the route of the vehicle at the guidance junction. Although the second guide object 70 is an image of a plurality of arrows pointing, the second guide object 70 alone may be used. Also, the second guide object 70 does not necessarily have to be a plurality of arrows, and may be one long arrow or line segment as long as it is arranged along the course of the vehicle. When the second guide object 70 is a single arrow or line segment, the width of the arrow or line segment is gradually reduced as the distance from the vehicle increases in accordance with the scale factors calculated in S15 and S16. to generate

Further, in the first embodiment, the actual scene image captured by the front camera 19 and the guide object are displayed on the liquid crystal display 15 of the navigation device 1. However, as a display for displaying the actual scene image and the guide object, a display in the vehicle can be used. A display other than the liquid crystal display 15 may be used as long as the display is arranged.

In the second embodiment, the front display 104 is configured to generate a virtual image in front of the windshield 105 of the vehicle 102 . Further, the object on which the image is reflected by the front display 104 may be a visor (combiner) installed around the windshield 105 instead of the windshield 105 itself.

In the first and second embodiments, the processing of the driving support processing program (FIG. 3) is executed by the navigation ECU 13 of the navigation device 1, but the executing body can be changed as appropriate. For example, the configuration may be such that the controller of the liquid crystal display 15, the vehicle control ECU, or other on-vehicle equipment executes.

REFERENCE SIGNS LIST 1 Navigation device 15 Liquid crystal display 19 Front camera 41 CPU 42 RAM 43 ROM 61 Driving guidance screen 62 Scenery 63 First guide object image 64 Second 2 guide object images, 65...first guide object, 66...guidance junction, 70...second guide object

Claims (5)

A superimposed image display device that is mounted on a vehicle and that superimposes a guide object that guides information to an occupant of the vehicle on the scenery around the vehicle for visual recognition,
object display means for displaying, along the route of the vehicle, the guide object that guides the route of the vehicle at the guidance junction when there is a guidance junction ahead of the vehicle in the direction of travel;
The object display means is
displaying the guide object in a size corresponding to an angle formed by an approach direction of entering the guidance junction on the route of the vehicle and an exit direction of exiting the guidance junction on the route of the vehicle;
A superimposed image display device for displaying the guide object in a smaller size as the angle is smaller. 2. The superimposed image display device according to claim 1, wherein the guide object includes a plurality of objects arranged at predetermined intervals along the course of the vehicle. The object display means is
determining the size of an object farthest from the vehicle, among the plurality of objects, according to the angle;
3. The superimposed image display device according to claim 2, wherein the plurality of objects are displayed with their sizes changed stepwise so that the farther the object is from the vehicle, the smaller the object. 4. The object display means according to any one of claims 1 to 3, wherein, when there is a guidance junction within a predetermined distance ahead of the vehicle in the traveling direction, the guidance object for guiding the vehicle at the guidance junction is displayed. The superimposed image display device according to 1. The object display means is
when the angle is 90 degrees or less, displaying the guide object in a size corresponding to the angle;
5. The superimposed image display device according to any one of claims 1 to 4, wherein when the angle is greater than 90 degrees, the guide object is displayed in a size obtained when the angle is 90 degrees.

Images