JP2023064957A - Superimposed image display device - Google Patents

Abstract

To provide a superimposed image display device which, when performing the guidance to encourage the lane change to the recommended lane using a guidance object superimposed on the scenery around the vehicle and displayed, suppresses the guidance with a sense of compulsion to encourage the lane change to the recommended lane and performs the guidance without urging the lane change to the recommended lane.SOLUTION: A superimposed image display device acquires the recommended lane which is recommended for driving on the road on which a vehicle is currently traveling and displays a guidance object to encourage the lane change to the recommended lane. On the other hand, when displaying the guidance object, if the travel lane of the vehicle which is currently traveling is different from the recommended lane, an area spanning from the travel lane to the recommended lane is displayed with the guidance object. A position of the end on the travel lane side of the area where the guidance object is displayed maintains a state where a relative position with respect to the vehicle is fixed.SELECTED DRAWING: Figure 3

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, for example, Japanese Patent Laid-Open No. 2014-48146 discloses a technique for performing guidance to prompt a lane change to a recommended lane in which the vehicle should travel by displaying an image superimposed on the surrounding environment. The captured image is displayed on the display unit, and if the remaining distance to the intersection is greater than the reference value and the vehicle is not traveling in the recommended lane for passing through the intersection, the vehicle included in the forward scenery is currently displayed. A technique is disclosed for displaying an image of an arrow leading to the recommended lane superimposed on the area from the lane in which the vehicle is traveling to the recommended lane.

JP 2014-48146 A (Fig. 5)

However, if guidance is provided in which an arrow image is superimposed on the road surface as disclosed in the above-mentioned Patent Document 1 as guidance for prompting a lane change to the recommended lane, the driver can immediately follow the arrow superimposed on the road surface. The user may feel as if he or she must change lanes to the recommended lane, and as a result, there is a risk that the user will be rushed to change lanes even when there is still time to complete the lane change.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. To provide a superimposed image display device that suppresses guidance with a sense of compulsion to urge a driver to change lanes and provides guidance without rushing to change lanes.

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. a recommended lane acquiring means for acquiring a recommended lane on which the vehicle is currently traveling, and an object display means for displaying the guide object for prompting a lane change to the recommended lane. and the object display means displays the guide object in an area extending from the travel lane to the recommended lane when the current lane in which the vehicle is currently traveling is different from the recommended lane. When displaying, the position of the edge of the area on the side of the driving lane remains fixed relative to the vehicle.
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 according to the present invention having the above-described configuration, when providing guidance for prompting a lane change to the recommended lane using the guidance object displayed superimposed on the scenery around the vehicle, the shape of the guidance object is the same as that of the vehicle. By starting from a position where the relative position to the vehicle is fixed, it is possible to suppress guidance with a sense of compulsion to change lanes to the recommended lane. becomes. As a result, it is possible to change lanes at the driver's timing without rushing to change lanes.

1 is a block diagram showing a navigation device according to a first embodiment; FIG. 4 is a flowchart of a driving support processing program according to the first embodiment; FIG. 4 is a diagram showing an example of a first guidance object displayed on the liquid crystal display; FIG. 10 is a diagram showing an example of a second guide object displayed on the liquid crystal display; 10 is a flowchart of a sub-processing program of a first guide object display position determination process; FIG. 2 is a diagram showing an example of recommended lanes when passing through guidance junctions on an expressway; FIG. 4 is a diagram showing an example of recommended lanes when passing through a guidance junction on a general road; It is a figure showing an example of the 1st guidance object. It is a figure showing an example of the 1st guidance object. It is a figure showing an example of the 1st guidance object. FIG. 10 is a diagram showing a change in the shape of the first guide object that accompanies a change in the position of the vehicle; FIG. 10 is a diagram showing transition of the display mode of the first guide object; FIG. 4 is a diagram showing an example of a first guidance object displayed on the liquid crystal display; FIG. 4 is a diagram showing an example of a first guidance object displayed on the liquid crystal display; FIG. 4 is a diagram showing an example of a first guidance object displayed on the liquid crystal display; FIG. 10 is a diagram showing an example of a mode of switching the display mode of the first guide object from the first display mode to the second display mode. FIG. 10 is a diagram showing an example of a mode of switching the display mode of the first guide object from the first display mode to the second display mode. FIG. 10 is a diagram showing an example of a mode of switching the display mode of the first guide object from the first display mode to the second display mode. FIG. 11 is a flowchart of a sub-processing program of second guide object display position determination processing; FIG. FIG. 11 is a diagram showing an example of arrangement of second guide objects; FIG. 10 is a diagram showing an example of a second guide object; FIG. 11 is a diagram showing an example of arrangement of second guide objects; FIG. 10 is a diagram showing the transition of the second guide object displayed on the 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;

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, road surface condition, number of lanes of the road, traffic classification of each lane in the direction of travel, Data representing places where the number of lanes decreases, places where the width becomes narrow, railroad crossings, etc. are related to corners. Data representing uphill roads, etc., and data representing expressways and general roads (national roads, prefectural roads, narrow streets, etc.) are recorded with respect to road types.

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.

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. 2) etc. described later, etc. in addition to the control program 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, the recommended lane acquisition means acquires a recommended lane on which the vehicle is currently traveling. The object display means displays a guide object for prompting a lane change to the recommended lane.

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 dot, distance to a guidance junction, position of the recommended lane in which the vehicle should travel, guidance prompting a lane change to the recommended lane, etc.), warnings displayed on the road surface (beware of rear-end collisions, speed limits, etc.), Lane marking, current vehicle speed, shift position, remaining energy level, advertisement image, facility information, guidance sign, map image, traffic information, news, weather forecast, time, connected smartphone screen, 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 along the guidance route, and the position of the recommended lane on the road on which the vehicle is currently traveling in order to pass the guidance junction along the guidance route. The guide image may be a guide image that shows the driver, a guide image that prompts the user to move to the recommended lane, 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. The captured image captured by the front camera 19 is also used to identify the lane on which the vehicle is currently running.

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. 2 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. 2, 5 and 19 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 description will be given of an example of processing in the case of displaying a guidance image prompting movement to a recommended lane as a guidance object. 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 arrows and the guide image. 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, if there is another branch point within 300 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 determines whether or not the distance to the next guidance branch point is less than a predetermined departure direction guidance start distance. The exit direction guidance start distance is a distance shorter than the guidance start distance which is the criterion for judgment in S2, and is determined according to the type of road on which the vehicle travels. 50m which is short.

If it is determined that the distance to the next guidance branch point is less than the exit direction guidance start distance (S3: YES), the process proceeds to S6. On the other hand, if it is determined that the distance to the next guidance branch point is not less than the exit direction guidance start distance (S3: NO), the process proceeds to S4.

Next, in S4, the CPU 41 performs first guide object display position determination processing (FIG. 5), which will be described later. In the first guidance object display position determination processing, a guidance image indicating the position of the recommended lane or a guidance image prompting movement to the recommended lane is targeted for display as a guidance object (hereinafter referred to as a first guidance object). This is processing for specifically determining the size and shape of the first guide object to be displayed and the position (range) for displaying the first guide object. The size and shape of the first guide object and the position to display the first guide object determined in S4 are determined by superimposing the guide object on the recommended lane in the scenery, the vehicle's driving lane, or the lanes between them. It is a condition for making the passenger visually recognize it.

Subsequently, in S5, the CPU 41 generates an image of the first guide object having the size and shape determined in S4, further transmits a control signal to the liquid crystal display 15, and sends the generated image to the liquid crystal display 15. The image of the first guide object obtained 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 first guide object superimposed on the scenery.

FIG. 3 is a diagram showing an example of the travel guidance screen 51 displayed on the liquid crystal display 15 in S5. As shown in FIG. 3, the liquid crystal display 15 displays a current scene 52 in front of the vehicle captured by the front camera 19 . Then, the image 53 of the first guide object is displayed superimposed on the scenery 52 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. The example shown in FIG. 3 is a driving guidance screen displayed when the current position of the vehicle is less than the guidance start distance and closer than the exit direction guidance start distance to the guidance junction (for example, 1 km to 300 m to the guidance junction). 51, a guidance image that guides the recommended lane 54 on which the vehicle is currently traveling in order to pass the guidance junction along the guidance route is displayed as the image 53 of the first guidance object. and a second display mode in which a guide image prompting movement to the recommended lane 54 is displayed as the image 53 of the first guide object.

As for the image 53 of the first guide object, as shown in FIG. 3, the recommended lane 54 in the scenery 52 is basically changed, or 54 are superimposed and displayed. Specifically, until the vehicle approaches the guidance branch point within a threshold value (for example, within 700 m on a highway), it is superimposed only on the recommended lane 54 regardless of whether the vehicle is traveling in the recommended lane 54 or not. and display (first display mode). The purpose of this stage is to make the occupant aware of the existence of the recommended lane 54 rather than prompting the vehicle to move to the recommended lane 54 .

After that, when the image 53 of the first guidance object is displayed and the vehicle approaches the guidance junction within a threshold value (for example, within 700 m on a highway) without moving to the recommended lane 54, the vehicle travels. A new image 53 of the first guide object superimposed on the area extending from the lane 55 to the recommended lane 54 is displayed (second display mode). This makes it possible to encourage the occupant who does not move to the recommended lane 54 to move to the recommended lane. In the first embodiment, when providing guidance to prompt movement to the recommended lane, the image 53 of the first guidance object is displayed in a wide area including the vehicle's driving lane 55 to the recommended lane 54. Compared to the case where an image such as an arrow is displayed, it is possible to suppress guidance with a sense of compulsion to urge the driver to change lanes to the recommended lane.

However, even if the vehicle approaches the guidance branch point within the threshold value (for example, within 700 m on a highway), it is not necessary to prompt the vehicle to move to the recommended lane when the vehicle is traveling in the recommended lane 54. Therefore, the first guidance object The image 53 is superimposed only on the recommended lane 54 (which also corresponds to the own vehicle driving lane 55) and displayed (first display mode).

Note that the distance to the guidance junction may be displayed on the image 53 of the first guidance object. After that, the process returns to S3, and the image 53 of the first guidance object is continuously displayed until the distance to the guidance junction becomes less than the exit direction guidance start distance. The first guide object will be described in more detail later.

On the other hand, in S6, the CPU 41 performs second guide object display position determination processing (FIG. 19), which will be described later. In the second guidance object display position determination processing, the arrow indicating the exit direction of the guidance junction is displayed as a guidance object (hereinafter referred to as a second guidance object), and the size of the second guidance object displayed on the liquid crystal display 15 is determined. This is the process of specifically determining the shape and the position (range) where the second guide object is to be displayed. Note that the size and shape of the second guide object determined in S6 and the position where the second guide object is displayed are, for example, a guide object located above the road at a predetermined distance from the vehicle in the scenery or above the road at a guidance junction. is superimposed and visually recognized by the occupant.

Subsequently, in S7, the CPU 41 generates an image of the second guide object having the size and shape determined in S6, further transmits a control signal to the liquid crystal display 15, and sends the generated image to the liquid crystal display 15. The image of the second guide object obtained is drawn at the position (range) determined in S6. 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 second guide object superimposed on the scenery.

FIG. 4 is a diagram showing an example of the travel guidance screen 51 displayed on the liquid crystal display 15 in S7. As shown in FIG. 4 , the liquid crystal display 15 displays a current scene 52 in front of the vehicle captured by the front camera 19 . Then, the image 57 of the second guide object is displayed superimposed on the scenery 52 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. The example shown in FIG. 4 is an example of the travel guidance screen 51 displayed when the current position of the vehicle approaches the guidance junction within less than the departure direction guidance start distance (for example, within 300 m to the guidance junction). Above the road on which the vehicle is currently traveling and along the future course of the vehicle, a plurality of arrows indicating the exit direction of the guidance junction are displayed as the image 57 of the second guidance object.

The image 57 of the second guide object includes images of a plurality of arrow-shaped objects. to be positioned at . The direction of each arrow indicates the exit direction of the guidance junction of the vehicle. Further, as will be described later, the image 57 of the second guidance object is displayed in a state in which the relative position with respect to the vehicle is fixed (hereinafter referred to as a first state) when the vehicle is away from the guidance junction. When the guidance junction is approached to a certain extent, the display is switched to a mode in which the relative position with respect to the guidance junction in the scenery 52 is fixed (hereinafter referred to as a second mode). In particular, in the second mode, a part of the image 57 of the second guidance object is fixed while being superimposed on the guidance junction. Therefore, when a vehicle occupant visually recognizes the travel guidance screen 51, it is possible to accurately grasp the route of the vehicle, the positions of the guidance branch points to be turned left or right, and the exit direction at the guidance intersection. After that, the image 57 of the second guidance object is continuously displayed until the vehicle passes the guidance junction. The second guide object will be described in more detail later.

After that, in S8, 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 (S8: YES), a control signal is transmitted to the liquid crystal display 15 to hide the guidance object displayed on the liquid crystal display 15. (S9). When the guidance object is hidden, the transmittance of the image of the displayed guidance object is increased step by step according to the distance to the guidance junction, and finally the vehicle reaches the guidance junction. It is desirable to set the transmittance to 100% at the timing of In addition, the captured image captured by the front camera 19, that is, the current scenery (actual scene image) around the vehicle (particularly in front of the vehicle) continues to be displayed for a certain period of time even after the guide object is hidden, and then displayed on the map image. Switch to display.

On the other hand, if it is determined that the vehicle has not passed through the guidance branch point (S8: NO), the process returns to S6 to continue displaying the guidance object.

Next, sub-processing of the first guide 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 the first guide object display position determination process.

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 identified.

Next, in S12, the CPU 41 specifies a "recommended lane", which is a recommended lane for driving on the road on which the vehicle is currently traveling, and a "vehicle driving lane", which is a driving lane where the vehicle is currently driving. Specifically, the recommended lane and the own vehicle driving lane are specified by the following processing. In S12, the positions of the "recommended lane" and the "vehicle driving lane" in the three-dimensional space generated in S11 are also identified.
[Recommended lane]
Based on the map information and the guidance route, the CPU 41 identifies, as a recommended lane, the lane through which the vehicle must travel in order to pass the guidance junction in front of the vehicle in the exit direction (guidance direction) along the guidance route. . More specifically, the lane corresponding to the exit direction of the vehicle at the guidance junction is acquired as the recommended lane. Note that the link data 32 included in the map information stores traffic classifications in the direction of travel for each lane, and the branch point data 34 stores the shapes of branch points. do. For example, as shown in FIG. 6, when the exit direction (guidance direction) at a guidance branch point 60 located in front of the vehicle traveling on the expressway is diagonally to the left of the access road, Of the 3 lanes on the road, the leftmost lane is the recommended lane. On the other hand, as shown in FIG. 7, when the exit direction (guidance direction) at the guidance branch point 60 located in front of the vehicle traveling on the general road is the right direction, the four lanes of the road on which the vehicle is traveling. Among them, the rightmost lane corresponding to the right-turn traffic division is the recommended lane. Note that the recommended lane is not limited to only one lane, and may be two or more lanes.
[Vehicle driving lane]
The CPU 41 performs image recognition processing on the captured image captured by the front camera 19, recognizes the lane markings drawn around the own vehicle, the edge of the road, and the surrounding vehicles. Information is also taken into consideration to identify the own vehicle driving lane. The link data 32 included in the map information stores the number of lanes and lane width for each road. For example, when driving on a three-lane highway shown in FIG. 6, the edge of the road on the left side of the vehicle can be detected, and it can be detected that there is one lane between the edge of the road and the lane in which the vehicle is traveling. If so, it can be determined that the vehicle is traveling in the second lane from the left, that is, the center lane. Similarly, the road edge on the left side of the vehicle can be detected, and if it is detected that there are two lanes between the road edge and the lane in which the vehicle is traveling, the vehicle will move to the third lane from the left, that is, the right lane. can be identified as running. Using the road edge on the right side of the vehicle also enables the lane in which the vehicle is traveling to be specified. The number of lanes existing between the road edge and the lane in which the vehicle is traveling is specified based on, for example, the detection result of lane markings and the detection result of other vehicles.

Subsequently, in S13, the CPU 41 determines whether or not the distance to the next guidance junction is less than a threshold. The threshold value is determined according to the road type of the road on which the vehicle travels.

Then, when it is determined that the distance to the next guidance junction is less than the threshold (S13: YES), the process proceeds to S17. On the other hand, when it is determined that the distance to the next guidance branch point is equal to or greater than the threshold (S13: NO), the process proceeds to S14.

In S14, the CPU 41 generates the first guide object 65 to be displayed. The first guide object 65 generated in S14 has a rectangular shape as shown in FIG. 8, the horizontal length is set to the lane width of the recommended lane, and the vertical length is set to 90 m, for example. Also, the distance to the guidance junction may be drawn inside. Also, the first guide object 65 is assumed to be 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 S14 can be changed as appropriate, and may be any shape other than a rectangle as long as it can indicate the recommended lane.

Further, at S14, 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 on the road surface of the recommended lane as shown in FIG. In addition, the height of installation shall be the same height as the road surface. After that, the process proceeds to S15.

Next, in S15, the CPU 41 can visually recognize the three-dimensional space in which the first guide object 65 is arranged in S14 when viewed from the current position of the vehicle and the height of the front camera 19 in the traveling direction of the vehicle. The size and shape of the first guide object 65 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 object stored in S15 are the same when the first guide object 65 arranged in the three-dimensional space is viewed from the viewpoint of the current vehicle (more precisely, the front camera 19). It is the size and shape of the visible first guide object 65 .

After that, in S16, the CPU 41 displays the liquid crystal display based on the current position of the vehicle and the position of the guidance junction in the three-dimensional space generated in S11 and the positions of the recommended lane and the driving lane of the vehicle specified in S12. The position of the recommended lane in the scenery 52 displayed on the screen 15 is estimated, and the range up to 90 m ahead of the vehicle's current position on the road surface of the estimated recommended lane is displayed on the liquid crystal display 15 as the position where the first guidance object 65 is displayed. to decide.

After that, the process proceeds to S5 to generate an image of the first guide object 65 having the size and shape determined in S16, furthermore, to transmit a control signal to the liquid crystal display 15, and The image of the first guide object 65 thus obtained is drawn at the position (range) determined in S17.

In S17, the CPU 41 determines whether or not the lane in which the vehicle is traveling matches the recommended lane, that is, whether or not the vehicle is traveling in the recommended lane based on the recommended lane and the lane in which the vehicle is traveling specified in S12. do.

If it is determined that the lane in which the vehicle is traveling matches the recommended lane, that is, the vehicle is traveling in the recommended lane (S17: YES), the process proceeds to S15. After S15, as described above, the rectangular first guidance object 65 superimposed on the recommended lane (which also coincides with the vehicle's driving lane) is generated (see FIG. 8), and the first guidance object to be displayed on the liquid crystal display 15 is displayed. Determine the size, shape, and position (range) to display the first guide object. On the other hand, if it is determined that the lane in which the vehicle is traveling does not match the recommended lane, that is, the vehicle is not traveling in the recommended lane (S17: NO), the process proceeds to S18.

In S18, the CPU 41 generates the first guide object 65 to be displayed. As shown in FIGS. 9 and 10, the first guide object 65 generated in S18 is generated as the vehicle moves in the direction opposite to the direction in which the vehicle is currently traveling across the recommended lane from the own vehicle's traveling lane. It becomes a widening shape that gradually spreads to the side of the lane. FIG. 9 shows the case where the own vehicle traveling lane and the recommended lane are adjacent, and FIG. 10 shows the case where the lane exists between the own vehicle traveling lane and the recommended lane. More specifically, a first area (rectangle) that is the road surface of the recommended lane from the current position of the vehicle to, for example, 90 m ahead, and is between the recommended lane and the own vehicle traveling lane and is adjacent to the first area, It has a shape combined with a second region (a right-angled triangle) whose width gradually narrows as it moves in the traveling direction of the vehicle.

In addition, the position of the end of the second region on the vehicle lane side (the right end in the example shown in FIGS. 9 and 10) maintains a state in which the relative position with respect to the vehicle is fixed. More specifically, it is fixed at the right corner position in front of the vehicle. Therefore, as shown in FIG. 11, for example, if the vehicle moves left or right, the position of the end of the second area changes accordingly, and the shape of the first guide object 65 changes accordingly. It should be noted that the recommended lane, the own vehicle driving lane, and the position of the own vehicle are specified in the above S11 and S12 in the three-dimensional space.

The horizontal length of the first area is set to the lane width of the recommended lane, and the vertical length is set to 90 m, for example. The lateral length of the second area changes depending on the position of the vehicle, and is the distance from the recommended lane to the front right corner of the vehicle. The vertical length of the second area is set to, for example, 45 m, which is half the length of the first area. Also, the distance to the guidance junction may be drawn inside. Also, the first guide object 65 is assumed to be a two-dimensional polygon and basically has no thickness. However, a thick three-dimensional polygon may be used. Further, the shape of the first guide object 65 generated in S22 can be changed as appropriate. Also good.

Further, at S18, the CPU 41 arranges the generated first guide object 65 in the three-dimensional space generated at S11. 9 and 10, the position where the first guide object 65 is arranged in the three-dimensional space is on the road surface extending from the driving lane of the vehicle to the recommended lane, and is 90 m from the current position of the vehicle. It is arranged in the range to the end. Further, as described above, the end of the first guide object 65 on the side of the driving lane (the right end in the example shown in FIGS. 9 and 10) is positioned at the right corner in front of the vehicle. In addition, the height of installation shall be the same height as the road surface. After that, the process proceeds to S19.

Next, in S19, the CPU 41 can visually recognize the three-dimensional space in which the first guide object 65 is arranged in S18 when viewed from the current position of the vehicle and the height of the front camera 19 in the traveling direction of the vehicle. The size and shape of the first guide object 65 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 object stored in S19 are the same as when the first guide object 65 arranged in the three-dimensional space is viewed from the viewpoint of the current vehicle (more precisely, the front camera 19). It is the size and shape of the visible first guide object 65 .

After that, in S20, the CPU 41 displays the liquid crystal display based on the current position of the vehicle and the position of the guidance junction in the three-dimensional space generated in S11 and the positions of the recommended lane and the driving lane of the vehicle specified in S12. The positions of the recommended lane and the vehicle's driving lane in the scenery 52 displayed in 15 are estimated, and the road surface extending from the estimated vehicle's driving lane to the recommended lane and the range from the current position of the vehicle to 90 m ahead. A position to display the first guide object 65 on the liquid crystal display 15 is determined. As described above, the display position is determined so that the end of the first guide object 65 on the driving lane side (the right end in the examples shown in FIGS. 9 and 10) is positioned at the right corner in front of the vehicle. do.

After that, the process proceeds to S5, in which an image of the first guide object 65 having the size and shape determined in S19 is generated, a control signal is transmitted to the liquid crystal display 15, and the The image of the first guide object 65 thus obtained is drawn at the position (range) determined in S20.

As a result of the above processing, when the distance from the vehicle to the guidance branch point is less than the guidance start distance and is equal to or greater than the exit direction guidance start distance, the driving guidance screen is displayed on the liquid crystal display 15 as the vehicle runs. 51 changes as shown in FIG. 12, resulting in screens such as those shown in FIGS.
Taking the example of a vehicle traveling on an expressway, when the distance from the vehicle to the guidance branch point is less than the guidance start distance (1km on expressways) and is equal to or greater than the threshold (700m on expressways), the "recommended An image 53 (first display mode) of the first guide object that guides the position of the lane is displayed. The "image 53 of the first guidance object for guiding the position of the recommended lane" is displayed superimposed on the recommended lane 54 as shown in FIG. 13 (S14 to S16). As a result, it becomes possible for the occupant to clearly grasp the existence and position of the recommended lane 54 .

In addition, when the distance from the vehicle to the guidance junction is less than the threshold value (700m on expressways) and is equal to or greater than the departure direction guidance start distance (300m on expressways), the "image of the first guidance object prompting movement to the recommended lane 53 (second display mode)" is newly displayed in place of the above-mentioned "image 53 (first display mode) of the first guide object for guiding the position of the recommended lane". However, the "image 53 of the first guidance object prompting movement to the recommended lane" is not displayed when the vehicle's driving lane 55 coincides with the recommended lane 54. In that case, as shown in FIG. The image 53 of the first guide object is displayed superimposed on the recommended lane 54 (own vehicle driving lane 55) along which the vehicle travels (first display mode). As a result, it is possible for the occupant to clearly understand that the vehicle is already traveling in the recommended lane 54 . On the other hand, when the own vehicle driving lane 55 and the recommended lane 54 do not match, as shown in FIG. (second display mode). As a result, it is possible for the occupant to clearly understand that the lane in which the vehicle is traveling is not the recommended lane but that the vehicle needs to move to the recommended lane. In addition, in the first embodiment, the image 53 of the first guidance object is displayed in a wide area including the vehicle driving lane 55 to the recommended lane 54. Therefore, the recommended guidance object is displayed as compared with the case where an image such as an arrow is displayed. It is possible to suppress guidance with a sense of compulsion to urge the driver to change lanes.

14 or 15 is displayed when the distance from the vehicle to the guidance branch point is less than the threshold value (700 m on the highway) and is equal to or greater than the exit direction guidance start distance (300 m on the highway). The positional relationship between the vehicle driving lane 55 and the recommended lane 54 at that time determines whether the display mode is to be displayed (that is, whether to display in the first display mode or the second display mode). Therefore, if the vehicle moves to the left recommended lane 54 while the driving guidance screen 51 of FIG. 15 is being displayed on the liquid crystal display 15, the driving guidance screen 51 of FIG. Similarly, if the vehicle moves to a lane other than the recommended lane 54 while the driving guidance screen 51 of FIG. 14 is displayed on the liquid crystal display 15, the driving guidance screen 51 of FIG.

After that, when the distance from the vehicle to the guidance junction becomes less than the departure direction guidance start distance (300 m on the highway), instead of the image 53 of the first guidance object, the exit direction of the guidance junction is displayed as described later. The image 57 of the second guide object indicated by the pointing arrow is newly displayed (see FIG. 23).

Further, in the first embodiment, the first display mode, in which the first guidance object is displayed only in the area corresponding to the recommended lane, is changed to the second display mode, in which the first guidance object is displayed in the area spanning from the own vehicle driving lane to the recommended lane. When switching to the display mode, the display mode is switched stepwise from the first display mode to the second display mode. Here, the timing at which the display mode of the first guidance object switches from the first display mode to the second display mode is as follows: Timing when the distance to the point reaches a threshold value (700m on highways), (2) Timing when the distance from the vehicle to the guidance branch point is within the threshold value and the vehicle moves from the recommended lane to a lane different from the recommended lane, is mentioned.

Further, as a method of switching the display mode from the first display mode to the second display mode step by step, the guide object displayed in the first area is common to the first display mode and the second display mode. Therefore, a method of maintaining the guide object displayed in the first area as it is and gradually expanding the range of displaying the guide object in the second area can be used. For example, as shown in FIG. 16, it is possible to gradually widen the display range of the guide object image 53 within the second area from the position adjacent to the rectangular first area. Conversely, it is also possible to gradually widen the display range of the guide object image 53 within the second area from the position farthest from the first area. Furthermore, as shown in FIG. 17, it is also possible to gradually widen the display range of the guide object image 53 within the second area from the position closest to the vehicle toward the direction of travel. In addition, when gradually expanding the display range of the image 53 of the guide object, it is desirable to perform animation display. In addition to the above example, as a method of gradually switching the display mode from the first display mode to the second display mode, the guide object displayed in the first area is maintained, and the guide object is displayed in the second area. A method of gradually lowering the display transmittance may also be mentioned. For example, as shown in FIG. 18, there is a method of gradually decreasing the transmittance of the guide object image 53 displayed in the second area from 100% (that is, the invisible state) with the passage of time.

In the first embodiment, as described above, the purpose of the display mode of the first guide object 65 is to encourage movement to the recommended lane from the first display mode, which does not aim to encourage movement to the recommended lane. When switching to the second display mode, the display mode is switched step by step from the first display mode to the second display mode. Therefore, it is possible to suppress guidance with a sense of compulsion to urge a lane change to a recommended lane.

Next, sub-processing of the second guide object display position determination processing executed in S6 will be described with reference to FIG. FIG. 19 is a flow chart of a sub-processing program of the second guide object display position determination process.

First, in S31, the CPU 41 acquires the distance from the current position of the vehicle to the coordinate X of the next guidance junction along the guidance route. For example, on an expressway, as shown in FIG. 20, the front vertex of the zebra band at the branch is set as the coordinate X of the guidance branch point.

Next, in S32, the CPU 41 determines whether or not the distance to the coordinate X of the guidance junction acquired in S31 is less than a predetermined threshold. It should be noted that the timing at which the distance to the coordinate X of the guidance branch point becomes the threshold is the timing of the guidance object displayed on the liquid crystal display 15 (displayed in the first mode) with the relative position to the vehicle fixed as in S33 described later. This is the timing at which at least part of the image is superimposed on the coordinate X of the guidance junction, that is, the timing at which at least part of the guidance object is superimposed on the guidance junction and visually recognized by the occupants of the vehicle. Details will be described later.

Then, if it is determined that the distance to the coordinate X of the guidance junction acquired in S31 is less than the threshold value (S32: YES), the process proceeds to S34. On the other hand, if it is determined that the distance to the coordinate X of the guidance junction acquired in S31 is equal to or greater than the threshold (S32: NO), the process proceeds to S33.

In S33, the CPU 41 sets the "position where the second guide object is superimposed on the scenery" to the position where the second guide object is superimposed and visually recognized with the relative position to the vehicle fixed by the occupant (the first position). position for displaying in the mode). Specifically, a position a predetermined distance ahead (for example, 10 m ahead) of the current position of the vehicle is set as the superimposed (arranged) position of the second guide object.

On the other hand, in S34, the CPU 41 sets "the position where the second guide object is superimposed on the scenery" to the position where the second guide object is superimposed and visually recognized while the relative position with respect to the guidance junction is fixed. (Position for displaying in the second mode). Specifically, it is a position where at least a part of the guide object is superimposed on the guide branch point (including its periphery) and visually recognized.

Next, in S35, the CPU 41 generates a three-dimensional space corresponding to the vicinity of the current position of the vehicle (especially the front in the direction of travel of the vehicle). In addition, the current position and direction of the own vehicle in the generated three-dimensional space and the position of the guidance branch point are also identified. The details are the same as those in S11, so they are omitted.

Subsequently, in S36, the CPU 41 generates the second guide objects 71 to 73 to be displayed on the liquid crystal display 15. FIG. In the first embodiment, the second guide objects 71 to 73 are arrows indicating the exit direction of the guide branch point ahead of the vehicle in the direction of travel. Generate arrows. If the guidance route is a route that turns right at a guidance intersection ahead in the traveling direction, the arrow indicates the right direction. If the guidance route is a route that turns left at a guidance intersection ahead in the direction of travel, the arrow indicates the left direction. Also, the second guide objects 71 to 73 are assumed to be two-dimensional polygons, and basically have no thickness. However, a thick three-dimensional polygon may be used. Further, the shape of the second guide objects 71 to 73 generated in S36 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. Moreover, it is not necessary to have three arrows, and only one arrow may be used.

Further, at S36, the CPU 41 arranges the generated second guide objects 71 to 73 in the three-dimensional space generated at S35. The positions at which the second guide objects 71 to 73 are arranged in the three-dimensional space are determined based on the "positions at which the second guide objects are superimposed on the scenery" set at S33 or S34.

For example, if the "position where the second guide object is superimposed on the landscape" is set to a position a predetermined distance forward (for example, 10 m forward) from the current position of the vehicle in S33, then as shown in FIG. Second guide objects 71 to 73 having three arrows are arranged at predetermined intervals above the road on which the vehicle 74 is currently traveling in the three-dimensional space and at positions ahead of the current position of the vehicle 74 by a predetermined distance. In addition, three second guide objects 71-73 are positioned at positions along the future path 75 of the vehicle. Here, FIG. 20 is a diagram showing an example of arrangement of the second guide objects 71 to 73 when a guide route is set to leave the guide branch point 60 of the highway to the left as an example. Specifically, as shown in FIG. 20, three second guide objects 71 to 73 are arranged at regular intervals along a route 75 of the vehicle. In particular, among the three second guide objects 71 to 73, the second guide object 71 closest to the vehicle from the current position of the vehicle is placed at a fixed predetermined distance (eg, 10 m). Here, the second guide objects 71 to 73 have the shape of an isosceles triangle and are arranged so as to be parallel to the direction intersecting the direction of travel (that is, to face the vehicle side). In addition, the second guide objects 71 to 73 indicate the exit direction by the direction of the apex angle with respect to the base. isosceles triangle shape. Also, although the arrangement intervals of the three second guide objects 71 to 73 can be changed as appropriate, they are set to 10 m intervals, for example. Further, the three second guide objects 71 to 73 are not arranged in parallel with the route 75 of the vehicle, but are guided with respect to the route 75 of the vehicle as the arrows visually recognized at positions closer to the guidance junction 60 are arranged. They are arranged so as to be located on the advancing direction side (left side in FIG. 17) of the branch point 60, gradually inclined. In particular, a condition that the plurality of second guide objects 71 to 73 do not overlap each other by a predetermined ratio (for example, 20%) when viewed from the vehicle 74 is also arranged as a condition. However, they may be arranged parallel to the traveling direction. On the other hand, in the vertical direction, as shown in FIG. 21, the lower ends of the second guide objects 71 to 73 are arranged at positions separated from the road surface by a predetermined distance (for example, 1 m).

On the other hand, if the "position where the second guide object is superimposed on the landscape" is set to a position where at least a part of the second guide object is superimposed on the guidance junction in S34, As shown in FIG. 19, second guide objects 71 to 73 having three arrows are arranged at predetermined intervals above the road on which the vehicle 74 is currently traveling in the three-dimensional space and at the position of the guide junction. In addition, three second guide objects 71-73 are positioned at positions along the future path 75 of the vehicle. Here, FIG. 22 is a diagram showing an example of arrangement of the second guidance object when a guidance route is set to leave the guidance junction 60 of the expressway to the left as an example. Specifically, as shown in FIG. 22, three second guide objects 71 to 73 are arranged at regular intervals along a route 75 of the vehicle. In particular, of the three second guide objects 71 to 73, the left end of the second guide object 73 closest to the traveling direction (the right end in the case of a rightward arrow) is the coordinate X of the guidance junction. and (horizontal direction). The coordinate X of the guidance branch point is specified from the map information possessed by the navigation device 1, but may be specified by performing image recognition processing on an image captured by the front camera 19. FIG. In that case, the vertex of the zebra band at the branch is taken as the coordinate X of the guidance branch point. Also, although the arrangement intervals of the three second guide objects 71 to 73 can be changed as appropriate, they are set to 10 m intervals, for example. Further, the three second guide objects 71 to 73 are not arranged in parallel with the route 75 of the vehicle, but are guided with respect to the route 75 of the vehicle as the arrows visually recognized at positions closer to the guidance junction 60 are arranged. They are arranged with a gradual incline so as to be located on the traveling direction side (left side in FIG. 19) of the branch point 60 . In particular, a condition that the plurality of second guide objects 71 to 73 do not overlap each other by a predetermined ratio (for example, 20%) when viewed from the vehicle 74 is also arranged as a condition. However, they may be arranged parallel to the traveling direction. On the other hand, in the vertical direction, as shown in FIG. 21, the lower ends of the second guide objects 71 to 73 are arranged at positions separated from the road surface by a predetermined distance (for example, 1 m).

Next, in S37, the CPU 41 determines, in the three-dimensional space in which the second guide objects 71 to 73 are arranged in S36, when viewed in the traveling direction of the vehicle from the current position of the vehicle and the height of the front camera 19. The sizes and shapes of the visible second guide objects 71 to 73 are stored as the sizes and shapes of the guide objects to be displayed on the liquid crystal display 15 . Here, the size and shape of the guide objects stored in S37 are obtained by visually recognizing the second guide objects 71 to 73 arranged in the three-dimensional space from the viewpoint of the current vehicle (more precisely, the front camera 19). It is the size and shape of the second guide objects 71 to 73 that can be visually recognized at the time.

Thereafter, at S38, the CPU 41 predicts the future course of the vehicle within the landscape 52 displayed on the liquid crystal display 15 based on the current position of the vehicle and the positions of the guidance junctions in the three-dimensional space generated at S31. Then, the range along the estimated route is determined as the position where the second guide objects 71 to 73 are to be displayed on the liquid crystal display 15 .

After that, the process proceeds to S7, the image of the second guide objects 71 to 73 having the size and shape determined in S37 is generated, and a control signal is transmitted to the liquid crystal display 15. The generated images of the second guide objects 71 to 73 are drawn in the positions (ranges) determined in S38.

As a result, the travel guidance screen 51 displayed on the liquid crystal display 15 as the vehicle travels becomes a screen as shown in FIG. First, when the distance from the vehicle to the guidance branch point becomes less than the departure direction guidance start distance (for example, 300 m), the image 53 of the first guidance object shown in FIGS. An image 57 of the guide object is superimposed and displayed on the scenery 52 in front of the vehicle in the traveling direction captured by the front camera 19 in the first mode. The position where the image 57 of the second guide object is first superimposed is a position relatively fixed with respect to the current position of the vehicle, for example, 10 m ahead of the vehicle. In the first mode, the occupant visually recognizes the image 57 of the second guide object superimposed while the position relative to the vehicle is fixed. For a while after that, the image 57 of the second guide object is superimposed and displayed in a state relatively fixed with respect to the current position of the vehicle. Since the relative position with respect to the vehicle is fixed, the display size of the displayed second guide object image 57 is also fixed.

After that, the vehicle approaches the guidance junction, and the image 57 of the second guidance object superimposed and displayed at a position fixed relative to the current position of the vehicle superimposes (reaches) the guidance junction (that is, YES is determined for the first time in S32), the first mode is switched to the second mode, and thereafter the image 57 of the second guide object is fixed in relative position to the guidance junction in the scenery 52. FIG. That is, the image 57 of the second guidance object is fixedly displayed at a position superimposed on the guidance junction. Switching from the first mode to the second mode does not change the guide object to be displayed, and the guide object to be displayed is the same before and after switching. That is, the guidance objects to be displayed are the same, and only the mode of display (the mode viewed by the passenger) is switched from the first mode to the second mode. In the second mode, the image 57 of the second guide object is superimposed and viewed by the occupant in a state where the relative position with respect to the guide branch point is fixed. After that, as the vehicle approaches the guidance junction, the image 57 of the second guidance object gradually becomes larger. Further, the transmittance of the image 57 of the second guidance object gradually increases, and the image 57 of the second guidance object disappears from the liquid crystal display 15 at the timing when the vehicle passes the guidance junction (S9).

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, the recommended lane on which the vehicle is currently traveling is acquired (S12). , a guidance object for prompting a lane change to the recommended lane is displayed (S5). The guidance object is displayed in the area extending from the driving lane to the recommended lane (S18 to S20), and the position of the edge of the area where the guidance object is displayed on the driving lane side remains fixed relative to the vehicle. In the case of providing guidance to prompt a lane change to the recommended lane by means of a guidance object superimposed on the scenery around the vehicle, the shape of the guidance object extends over a wide area from the driving lane of the vehicle to the recommended lane, By adopting a shape that starts from a position where the relative position with respect to is fixed, it is possible to suppress guidance with a sense of compulsion to urge a lane change to the recommended lane. As a result, it is possible to change lanes at the driver's timing without rushing to change lanes.
Further, in the case of displaying the guide object, when a predetermined condition is satisfied, the guide object is displayed in the area extending from the driving lane to the recommended lane from the first display mode in which the guide object is displayed only in the area corresponding to the recommended lane. When switching to the second display mode to be displayed and switching from the first display mode to the second display mode, the display mode is switched stepwise from the first display mode to the second display mode. Therefore, switching to the guidance prompting the lane change to the recommended lane is performed over time, so that it is possible to suppress guidance with a sense of compulsion to prompt the lane change to the recommended lane. As a result, it is possible to change lanes at the driver's timing without rushing to change lanes.
Further, the area where the guide object is displayed in the first display mode is the first area, which is the road surface of the recommended lane from the current position of the vehicle to the predetermined distance ahead, and the guide object is displayed in the second display mode. The area includes a first area and a second area, which is a road surface between the driving lane and the recommended lane and is adjacent to the first area, and a transition from the first display mode to the second display mode. In the case of switching, the guidance object displayed in the first area is maintained, and the range in which the guidance object is displayed in the second area is gradually expanded. By switching to guidance that prompts a change, it is possible to suppress guidance that has a sense of compulsion that prompts a lane change to the recommended lane. As a result, it is possible to change lanes at the driver's timing without rushing to change lanes.
Further, when there is a guidance junction within a predetermined guidance start distance ahead of the vehicle in the traveling direction, the lane corresponding to the exit direction of the vehicle at the guidance junction is obtained as a recommended lane (S12). It is possible to use the guide object to prompt the occupant to move to the recommended lane for driving when passing through.
In addition, since the area where the guide object is displayed has a shape that gradually widens toward the lane in which the vehicle is currently traveling as it moves in the direction opposite to the traveling direction of the vehicle, the shape of the guide object can be visually recognized to allow the vehicle to travel. It is possible to easily grasp the relative position of the recommended lane with respect to the lane to be used.

[Second embodiment]
Next, a superimposed image display device according to the second embodiment will be described with reference to FIGS. 24 and 25. 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. 24 . FIG. 24 is a schematic configuration diagram of a superimposed image display device 101 according to the second embodiment.
As shown in FIG. 24 , 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 guidance object is displayed on the front display 104 as necessary. In the second embodiment described below, as in the first embodiment, the guidance object is an arrow indicating the exit direction of the guidance junction along the guidance route, and an arrow indicating the exit direction of the guidance junction along the guidance route. The guide image indicates the position of the recommended lane on which the vehicle is currently traveling, and the guide image prompts the user to move to the recommended lane.

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. . As a result, a virtual image 121 of the guide object image 120 is superimposed on the scenery through the windshield 105 by visually recognizing the guide object image 120 displayed on the front display 104 as shown in FIG. visible.

Accordingly, as in the superimposed image display device according to the first embodiment, it is possible to accurately grasp the position of the recommended lane and the exit direction at the proposed branch point. In addition, in the superimposed image display apparatus according to the second embodiment, in the guidance object display position determination processing of S4 and S6, the size and shape of the guidance object to be displayed on the front display 104 and the position ( range). Also, the current position and direction of the own vehicle specified in the three-dimensional space in S11 and S35 are preferably 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.

In addition, in the first and second embodiments, the position of the end of the first guide object on the traffic lane side (the right end in the examples shown in FIGS. 9 and 10) is fixed at the right corner in front of the vehicle. However, if the position relative to the vehicle is fixed, it does not necessarily have to be at the front right corner of the vehicle. For example, it may be fixed at a central position in front of the vehicle.

Further, in the first and second embodiments, instead of the first display mode in which the first guidance object is displayed only in the area corresponding to the recommended lane, the first guidance object is displayed in the area extending from the own vehicle driving lane to the recommended lane. When switching from the first display mode to the second display mode, the display mode is switched step by step from the first display mode to the second display mode. In the case of switching between , the display mode may be switched step by step.

In addition, in the first and second embodiments, the guidance objects are the first guidance object 65 that guides the vehicle to the recommended lane, and the second guidance object that is an arrow indicating the exit direction of the vehicle at the guidance junction ahead in the direction of travel. Although 71 to 73 are used, only the first guide object 65 may be used. Also, the first guide object 65 does not necessarily have to be a rectangular shape superimposed on the lane or a shape combining a rectangle and a triangle. Other shapes may be used.

In addition, in the first and second embodiments, the guidance object is used to guide the guidance branch point, but the point to be guided by the guidance object is not limited to the guidance branch point. A guide object may be used to prompt the vehicle to move to the recommended lane when passing through a point or a merging section.

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.

Further, in the first and second embodiments, the navigation ECU 13 of the navigation device 1 executes the processing of the driving support processing program (FIG. 2), 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 51 travel guidance screen 52 landscape 53 image of first guidance object 54 recommended lane , 55... Vehicle driving lane 57... Image of second guide object 60... Guidance branch point 65... First guide object 71 to 73... 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,
a recommended lane obtaining means for obtaining a recommended lane on which the vehicle is currently traveling;
an object display means for displaying the guide object for prompting a lane change to the recommended lane;
The object display means is
displaying the guidance object in an area extending from the driving lane to the recommended lane when the driving lane, which is the lane in which the vehicle is currently driving, is different from the recommended lane;
A superimposed image display device, wherein, when displaying the guide object, the position of the edge of the area on the side of the driving lane remains fixed relative to the vehicle. The object display means is
From a first display mode in which the guide object is displayed only in the area corresponding to the recommended lane when a predetermined condition is satisfied, to a second display mode in which the guide object is displayed in an area spanning from the driving lane to the recommended lane. switch to display mode,
The superimposition according to claim 1, wherein when switching from the first display mode to the second display mode, the display mode is switched stepwise from the first display mode to the second display mode. Image display device. The area where the guide object is displayed in the first display mode is a first area that is the road surface of the recommended lane from the current position of the vehicle to a predetermined distance ahead,
In the second display mode, the areas for displaying the guide object are the first area and a second area adjacent to the first area on the road between the driving lane and the recommended lane. , including
The object display means maintains the guide object displayed in the first area and displays the guide object in the second area when switching from the first display mode to the second display mode. 3. The superimposed image display device according to claim 2, wherein the display range is gradually expanded. wherein said recommended lane acquiring means acquires, as said recommended lane, the lane corresponding to the exit direction of the vehicle at said guidance junction when there is a guidance junction within a predetermined guidance start distance ahead of said vehicle in the direction of travel of said vehicle. The superimposed image display device according to any one of claims 1 to 3. When the guidance object is displayed in an area extending from the driving lane to the recommended lane, the area in which the guidance object is displayed has a shape that gradually widens toward the driving lane as the vehicle moves in a direction opposite to the direction in which the vehicle travels. 5. The superimposed image display device according to any one of claims 1 to 4.

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