JPH10227649A - Navigator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigator for performing path search and path guidance considering a U turn. SOLUTION: A navigation controller 1 includes a map buffer 16 for storing various kinds of data for map display and path search, a path search processing part 36 for performing path search processing, and a guidance path memory 38. The map buffer 16 has map data that associate the U-turn path of a road to an individual link and the path search processing path 36 performs path search by including also a link corresponding to the U-turn path in a search target. When a link corresponding to the U-turn path is included in the searched path, a path for U turn is set on the road.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device for displaying a searched guidance route on a map.

[0002]

2. Description of the Related Art Generally, an on-vehicle navigation device detects a current position of a vehicle, reads map data near the current position from a CD-ROM, and displays the map data on a screen. Also,
In the center of the screen, a vehicle position mark indicating the vehicle position is displayed, and the map data in the vicinity is scrolled according to the progress of the vehicle around the vehicle position mark so that the map information around the vehicle position can be always understood. Has become.

[0003] Usually, a navigation device mounted on a vehicle is equipped with a route guidance function that enables a driver to travel to a desired destination without making a mistake on a road. According to this route guidance function, the lowest cost route from the departure point to the destination is automatically searched for by using simulation data such as the horizontal search (BFS) method or the Dijkstra method using the map data, and the search is performed. The route should be stored as a guidance route, and while driving, the guidance route should be drawn thicker with a different color from other roads on the map image and displayed on the screen, or the vehicle should change the course on the guidance route When approaching the intersection within a certain distance, the intersection is enlarged and displayed to display an arrow indicating the traveling direction, thereby guiding the driver to the destination.

The cost is a value obtained by multiplying a road width, a road type (such as a general road or an expressway), a right turn, a left turn, and other predetermined constants based on the distance. The degree of appropriateness is quantified. Even if there are two routes having the same distance, the cost differs depending on whether the driver specifies whether to use the expressway, whether to give priority to time or distance, and the like.

[0005]

When a conventional navigation device searches for a guidance route, the vehicle actually travels on a road having a median strip where a U-turn road is set, and turns the U-turn road back. Even if the person arrives at the destination with the minimum cost, the route search processing involves the road (link) branching off from the currently running road (link). Is set. The same applies to a case where a route search is performed again, for example, when passing through a destination.
If you can make a U-turn at any point on the running road, even if you can return to the destination at the shortest cost,
A route that reaches the destination by repeatedly turning right or left at an appropriate branch is searched. In addition, when a route search is performed so that the destination is always on the left side of the road, and when a U-turn can be made after passing the destination on the right side, a guidance route can be set at the shortest cost, The established guidance route is set.

[0006] Further, it is not limited to the case where the guidance route is set by the route search as described above or the vehicle deviates from the preset guidance route, and it is desired to enter the cul-de-sac and return the currently traveling road. Even in such cases, the driver must search for a U-turnable point at his own discretion, and the navigation device cannot be used.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide a navigation device capable of performing a route search and a route guidance in consideration of a U-turn. .

It is another object of the present invention to provide a navigation device capable of displaying a U-turn point on a map.

[0009]

In order to solve the above-mentioned problems, a navigation device according to the present invention includes information on whether or not a turn on a road is possible in map data stored in a map data storage means. By performing the search processing by the route search means using the map data, it is possible to set a traveling route that allows turning on the road and to perform route guidance using this route. Such a route search can be performed by treating the U-turn road as an independent link and creating map data, or creating map data in which whether or not a U-turn is allowed is provided as attribute information of the node.

In the navigation apparatus according to the present invention, the map data stored in the map data storage means includes information on whether or not a turn on a road is possible, and a map is displayed based on the map data. It is possible to display a predetermined mark (U-turn mark) at a turnable position on the road, superimposed on a map display of a predetermined range.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A navigation apparatus to which the present invention is applied adds information on whether or not a U-turn is possible on a road to map data recorded on a CD-ROM, and makes it necessary when searching for a route. It is characterized by setting a guidance route that turns back on the road. Alternatively, it is characterized in that a U-turnable point on a road is simply displayed on a display screen. Hereinafter, a navigation device according to an embodiment will be described with reference to the drawings.

(1) Overall Configuration of Navigation Apparatus FIG. 1 is a diagram showing the overall configuration of an on-vehicle navigation apparatus according to an embodiment of the present invention. The navigation apparatus shown in FIG. 1 includes a navigation controller 1 that controls the entire system, a CD-ROM 2 that stores various map data necessary for map display, route search, and the like.
A disk reader 3 for reading map data recorded in the ROM 2, a remote control (remote control) unit 4 as an operation unit for a driver or a passenger to input various instructions, and detection of the position and orientation of the vehicle Receiver 5 and autonomous navigation sensor 6 that perform navigation, a display device 9 that displays a map image and a guidance route superimposed on the map image, and an audio unit 10 that outputs a predetermined guidance voice when performing route guidance
And

The above-described disk reading device 3 can be loaded with one or a plurality of CD-ROMs 2 and any one of the CD-ROMs 2 is controlled by the navigation controller 1.
-Read map data from the ROM 2. The remote control unit 4 includes a search key for giving a route search instruction,
Route guidance mode key used for setting the route guidance mode, destination input key, left / right / up / down cursor keys, map reduction /
Various operation keys such as an enlargement key and a setting key for fixing an item at a cursor position on the display screen are provided, and an infrared signal corresponding to an operation state of the key is transmitted to the navigation controller 1. The remote control unit 4 has a U-turn key for displaying a turnable position on a road at the time of a route guidance operation or a simple map display operation.

The GPS receiver 5 receives radio waves transmitted from a plurality of GPS satellites, performs three-dimensional positioning processing or two-dimensional positioning processing, and calculates the absolute position and direction of the vehicle (the vehicle direction is the current Is calculated based on the own vehicle position and the own vehicle position one sampling time ΔT before), and these are output together with the positioning time. The autonomous navigation sensor 6 includes an angle sensor 12 such as a vibrating gyroscope that detects the vehicle rotation angle as a relative bearing, and a distance sensor 14 that outputs one pulse every predetermined traveling distance. Detect position and orientation.

The display device 9 displays map information around the own vehicle together with a vehicle position mark, a departure point mark, a destination mark, etc., based on the image data output from the navigation controller 1, or displays the map information on this map. For example, displaying a guidance route. In addition, this display device 9
Displays a U-turn mark at a turnable position on the guidance route when the U-turn key of the remote control unit 4 is pressed.

(2) Detailed Contents of Map Data Next, details of the map data recorded on the CD-ROM 2 will be described. The map data recorded on the CD-ROM 2 is in units of figures separated by a predetermined longitude and latitude, and the map data of each figure can be specified and read by specifying a figure number. Becomes The map data for each map includes a drawing unit composed of various data necessary for map display, a road unit composed of data necessary for various processes such as map matching, route search, and route guidance, and an intersection. An intersection unit consisting of detailed data of the intersection is included. The above-mentioned drawing unit includes VICS conversion layer data necessary for specifying a corresponding road from traffic congestion information sent from the VICS center, and a background layer necessary for displaying buildings or rivers. It includes data and character layer data necessary for displaying municipal names, road names, and the like.

In the above-described road unit, a line connecting an intersection on a road to another adjacent intersection is called a link, and an intersection connecting two or more links is called a node.
FIG. 2 is a diagram showing the overall configuration of the above-described road unit. As shown in the figure, the road unit has a unit header for identifying a road unit, a connection node table storing detailed data of all nodes, and a node table indicating a storage position of the connection node table. And a link table storing detailed data of a link specified by two adjacent nodes.

FIG. 3 is a diagram showing the detailed contents of various tables included in the road unit. As shown in FIG. 3A, the node table includes node records # 0, # 1,... Corresponding to all the nodes included in the target leaf.
Is stored. Each node record is #
Node numbers are given in order from 0, and indicate the storage position of the connection node table corresponding to each node.

FIG. 3B shows the connection node table.
For each of the existing nodes, a. Normalized longitude / latitude, b. "Node attribute flag" including an intersection node flag indicating whether or not this node is an intersection node, an adjacent node flag indicating whether or not this node is a node at a boundary with another figure, c. "The number of connected nodes" indicating the number of nodes forming the other end of each link when there is a link having this node as one end of the link; d. No right turn or U
"Number of traffic restrictions" that are present if there are traffic restrictions such as turn prohibition, e. Connection node records for the number of links indicating the link number of each link having this node at one end; f. A traffic regulation record indicating the specific content of the traffic regulation corresponding to the number of the traffic regulations, if any, g. If this node is a node at a boundary with another figure leaf, an “adjacent node record” indicating the position of the connection node table of the corresponding node of the neighboring figure leaf, h. If this node is an intersection node, the storage location and size of the corresponding intersection record in the intersection unit are included.

Further, as shown in FIG. 3C, the link table includes a plurality of link records in the order of link numbers corresponding to all the links included in the target figure. Each of these link records: a. A link ID, which is a code assigned to each link mainly for displaying a search route, b. Node number 1 and node number 2 identifying the two nodes located at both ends of the link; c. Link distance, d. The actual time required to travel this link is statistically calculated as a cost (for example, the actual time required to travel on an ordinary road or highway at an average speed is indicated by a multiplier. Value), e. Various road attribute flags including road attribute information associated with this link; f. A road type flag indicating whether the actual road corresponding to this link is an expressway or a general road; g. The route number assigned to the road corresponding to this link is included.

(3) Detailed Configuration and Operation of Navigation Controller Next, a detailed configuration of the navigation controller 1 shown in FIG. 1 will be described. The navigation controller 1 includes a map buffer 16 for displaying a predetermined map on the display device 9 based on the map data read from the CD-ROM 2, a map reading control unit 18, a map drawing unit 20, a VRAM 22, a reading control unit 24, Image synthesis unit 26
A data storage unit 30, a vehicle position / azimuth calculation unit 32 for performing calculation of the vehicle position, map matching processing, route search processing, and route guidance processing and displaying the results.
The map matching processing unit 34, the route search processing unit 36, the guidance route memory 38, the guidance route drawing unit 42, the mark image generation unit 44, the intersection guidance unit 46, and various operation screens for the user are displayed. A remote controller control unit 60 for transmitting the operation instruction to each unit, a cursor position calculation unit 62, and an operation screen generation unit 64 are provided.

The map buffer 16 includes the disk reader 3
Is for temporarily storing the map data read from the CD-ROM 2 by the above method. Map reading control unit 1
When the center position of the screen is calculated by the controller 8, an instruction to read map data in a predetermined range including the center position of the screen is sent from the map reading control unit 18 to the disk reader 3, and the map data necessary for map display is stored on the CD. Read out from the ROM 2 and stored in the map buffer 16; For example, map data corresponding to four sheets including the screen center position is read out and stored in the map buffer 16.

The map drawing section 20 creates a map image necessary for display based on the drawing units included in the map data of the four figures stored in the map buffer 16. The created map image data is stored in the VRAM 22, and the read control unit 24 reads one screen of map image data. The image synthesizing unit 26 performs image synthesis by superimposing each image data output from each of the mark image generating unit 44, the intersection guidance unit 46, and the operation screen generating unit 64 described later on the read map image data. The synthesized image is displayed on the screen of the display device 9.

FIG. 4 is a diagram showing the relationship between the map image data stored in the VRAM 22 and the display image read by the read control unit 24. In the figure, each of the areas A to D is a map image drawn based on the drawing unit included in the map data of the four figures read from the map buffer 16, and the map images of these four figures are shown. The data is stored in the VRAM 22. The area P is centered on the screen center position O by the read control unit 24 by the VRAM2.
2 shows the display image data read out from the display area 2, and when the vehicle travels and the screen center position O corresponding to the own vehicle position moves, the area P moves with the movement, and the screen is scrolled.

The data storage unit 30 sequentially stores positioning position (own vehicle position) data output from the GPS receiver 5. Further, the vehicle position / direction calculation unit 32 calculates the absolute position and direction of the vehicle from the relative position and direction of the vehicle output from the autonomous navigation sensor 6. The map matching processing unit 34 uses the GP stored in the data storage unit 30
It is determined whether or not the own vehicle position by the S receiver 5 or the own vehicle position calculated by the vehicle position / azimuth calculation unit 32 exists on the road in the map data. The process of correcting the own vehicle position is performed. As typical methods of map matching, pattern matching and projection are known.

When the destination input key is pressed after the cursor is moved to a specific location on the map by operating the cursor keys of the remote control unit 4, the route search processing unit 36
At this time, the cursor position calculated by the cursor position calculator 62 is set as the destination of the route search. The set destination data is stored in the guidance route memory 38.
When the search key of the remote control unit 4 is pressed, the route search processing unit 36 sets the own vehicle position corrected by the map matching processing unit 34 as a departure point, stores the vehicle position in the guidance route memory 38, and A search is made for a traveling route connecting the departure point and the destination stored in the guidance route memory 38 under predetermined conditions. For example, a guidance route that minimizes the cost under various conditions such as the shortest time, the shortest distance, and the priority on general roads is set. As typical methods of the route search, the Dijkstra method and the horizontal search method are known, and details thereof will be described later. The guidance route set by the route search processing unit 36 in this way is stored in the guidance route memory 38.

FIG. 5 is a diagram showing an example of data stored in the guidance route memory 38. As shown in the drawing, the data of the guide route set by the route search processing unit 36 is a set of nodes NS, N1, N from the starting point to the destination.
, ND, and are stored in the guidance route memory 38.

The guidance route drawing unit 42 stores the guidance route memory 3
8 from the guidance route data stored in
Those included in the map area drawn in the RAM 22 are selected, and a guidance route which is superimposed on a map image with a predetermined color and emphasized thickly is drawn. In addition, when the U-turn key of the remote control unit 4 is pressed, the guidance route drawing unit 42 draws a predetermined U-turn mark at a turnable position on the guidance route in parallel with the drawing operation of the guidance route. The mark image generating unit 44 generates a vehicle position mark at the position of the own vehicle after the map matching processing, or generates a cursor mark having a predetermined shape.

The intersection guidance section 46 provides guidance at the intersection where the vehicle is approaching by using a display image and voice. When the vehicle actually navigates the route, the own vehicle approaches within a predetermined distance from the intersection in front of the guidance route. At this time, the guide map (the enlarged view of the intersection, the destination, the traveling direction arrow) of the approaching intersection is displayed on the screen of the display device 9, and the traveling direction is guided by audio through the audio unit 10.

The above-described map buffer 16 serves as map data storage means, and the route search processing section 36 serves as route search means. The map drawing section 20, VRAM 22, readout control section 24, image synthesizing section 26, and U-turn mark drawing section 40 are provided. Each corresponds to a map display means.

(4) Operation of Navigation Apparatus The entire navigation apparatus and the navigation controller 1 have the above-described configurations. Next, a route search operation taking a U-turn into account will be described.

FIG. 6 is a diagram showing an example of nodes and links according to the present embodiment set corresponding to a road having a median strip. On a road with a median strip as shown in FIG. 6 (A), the U
Turns may be possible. FIG. 6 (B)
It is an example of a link and a node of this embodiment corresponding to the road of the same figure (A). A node is set in each of an up lane and a down lane corresponding to a break part of a median strip. A link for a U-turn road is set corresponding to the traversing route. Therefore, in the related art, as shown in FIG. 6 (C), the up lane and the down lane are simply represented by separate links, and the up lane to the down lane or the down lane in the middle of the link. Those that could not return to the ascending lane from above can be returned in the same manner as when branching off a normal link.

Next, the outline of the route search processing performed by the route search processing unit 36 will be described using a horizontal search method as an example. FIG. 7 is a diagram for explaining the outline of the route search processing, in which a road is represented by a straight line and an intersection is represented by a graph as an intersection of straight lines. The cost between each intersection is the cost of the link existing between the intersections. (Accurately, a cost is set in consideration of the time when making a right or left turn at each intersection, and added to the cost calculated only by the link to obtain the total cost). For example, the starting point S is set to the node n9, the destination D is set to the node n21, and the search order is set to i.

In the horizontal search method, the node n9 is set as the departure point S when finding the route from the nodes n9 to n21 (the search order i =
0), nodes n4, n8, n14, and n10 are found as intersections adjacent to node n9 with search order i = 1, and nodes n3 and n5 (n9 is already on the route as intersections adjacent to node n4 with search order i = 2). Are excluded because of the existence of nodes n3 and n3 as intersections adjacent to node n8.
7, n13 is found. Here, since the node n3 is hit, the cost (L94 +
L43) is compared with the magnitude of the cost (L98 + L83), and the node having the smaller total cost is stored in the guidance route memory 38 as the intersection just before n3.

As described above, the search proceeds sequentially, and when the search node reaches the destination node n21 with the search order m, the search process is completed, and a series of node numbers are stored in the guide route memory 38 as shown in FIG. It should be noted that the cost is not always minimum even when reaching the destination node in this way,
An improved type that does not end the search even if it reaches the destination node via one route, and continues the search until the cost of another route being searched exceeds the cost of the route that has reached the destination so far. May be adopted.

By the way, in this embodiment, FIG.
As shown in (B), a node and a link for a U-turn road are set, and a branch always occurs at this node.
The node for the U-turn road is treated as an intersection node, and is included in each node shown in FIG. Therefore, just add nodes and links for U-turn roads,
The search processing exactly the same as the conventional one becomes possible.

Further, by increasing the cost of traveling on the link corresponding to the U-turn road in consideration of the time required for actually making the U-turn, a route setting close to the actual traveling state can be set. It can be carried out. As a method to increase the cost of the link corresponding to the U-turn road,
Information indicating that the road corresponding to this link is a U-turn road is stored in the road type flag in the link record shown in FIG. 3C, and the cost is set to a large value. A case may be considered where the multiplier stored in “cost” is set to a large value.

In this way, it is possible to search for a route while allowing a turn on the road in consideration of the U-turn, and as shown in FIG. Make a left turn and enter this road, or make a U-turn after passing a destination on the opposite side of the road as shown in FIG. And so on.

In the above description, as shown in FIG. 6B, a road having a median strip is represented by a link corresponding to each of an up lane and a down lane and a link corresponding to a U-turn road. However, when the upper and lower lanes are represented by one link, the link corresponding to the U-turn road may not be particularly provided, and the attribute information of the node may have information on the availability of the U-turn.

FIG. 9 is a diagram showing an example in which one link corresponds to the upper and lower lanes of a road having a median strip.
The road with the median strip shown in FIG. 9A is shown in FIG.
And the U-turn of the vehicle is enabled at the cut portion of the median strip. FIG.
(B) is an example of a link and a node according to another embodiment corresponding to this road. A node is set corresponding to a break of a median strip where a U-turn is possible, and the upper and lower sides of other roads are set. The lane is represented by one link.

FIG. 3B shows such a node.
Contains the U-turn flag indicating that this node is a U-turn node, and the traffic regulation record does not include information indicating that the U-turn is regulated. (That is, nodes other than the U-turn node include a traffic control record indicating that U-turn is prohibited, and only the U-turn node does not include such a traffic control record).

When a route search process is performed taking such a U-turn node into consideration, each node shown in FIG. 7 must include a U-turn node in addition to an intersection node. In addition, in the case of looping back at the U-turn node, it is necessary to perform a search without excluding a node that appeared before in searching for the next adjacent node.

In this way, it is possible to search for a route in which a U-turn is taken into consideration even for a road in which the upper and lower lanes are represented by a single link, and the traveling route as shown in FIGS. Can be set.

In the above description, a route search is performed by setting a link or a node for a U-turn road, or by setting a node that has a node attribute indicating that a U-turn is possible. Thus, the guidance route including the U-turn road is searched for, but the U-turn-possible position may be displayed so as to be superimposed on the map image when the map is simply displayed.

For example, when the U-turn key of the remote control unit 4 is pressed, the U-turn mark drawing section 4 shown in FIG.
0 refers to the connection node table included in the road unit of the map data stored in the map buffer 16, extracts the node where the U-turn flag is set in the attribute flag of the node, and displays the vicinity of the display position of this node in the VRAM 22. To U
Draw a turn mark. FIG. 10 is a view showing an example of the U-turn mark displayed on the screen of the display device 9 in this manner. The U-turn mark indicated by A travels from the own vehicle position mark B direction. In case,
This indicates that a U-turn is possible at this position.

In this case, a U-turn mark is displayed on the entire screen. If a guidance route is set, the U-turn mark existing on the guidance route is displayed. You may do so. In order to perform such display, the U-turn mark drawing unit 40 only needs to check whether or not each of the nodes stored in the guidance route memory 38 is a U-turn node. Simplification is possible.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. In the above-described embodiment, the case where the route search is performed in consideration of the U-turn has been described. As a modified example, for example, when the vehicle enters a road of a dead end or traveling on a road with a median strip, When the driver presses the U-turn search key of the remote control unit 4 while the vehicle is in the vehicle, a route including a U-turn that travels in the opposite direction from the front in the traveling direction may be searched.
In this case, the next node in the traveling direction of the vehicle may be set as the departure point, and the immediately preceding node may be set as the destination.

[0048]

As described above, according to the present invention, the map data stored in the map data storage means includes information on whether or not a turn on a road is possible, and the map data is used. By performing the search processing by the route search means, it becomes possible to set a traveling route that allows turning on the road and to perform route guidance using this route.

Further, the map data stored in the map data storage means includes information on the possibility of turning back on a road, and a map is displayed based on the map data, thereby providing a map within a predetermined range. A predetermined mark can be displayed at a turnable position on the road so as to overlap the display.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a vehicle-mounted navigation device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an entire configuration of a road unit.

FIG. 3 is a diagram showing detailed contents of various tables included in a road unit.

FIG. 4 is a diagram showing a relationship between a drawing area and a display area of a VRAM.

FIG. 5 is a diagram showing an example of data stored in a guidance route memory.

FIG. 6 is a diagram illustrating an example of nodes and links according to the present embodiment set corresponding to a road having a median strip;

FIG. 7 is a diagram illustrating an outline of a route search process.

FIG. 8 is a diagram showing a specific example of a traveling route in which a road is turned back.

FIG. 9 is a diagram illustrating another example of nodes and links according to the present embodiment that are set corresponding to a road having a median strip.

FIG. 10 is a diagram showing a map screen displaying a U-turn mark at a U-turn-enabled position on a road.

[Explanation of symbols]

 Reference Signs List 1 navigation controller 9 display device 16 map buffer 20 map drawing unit 22 VRAM 24 readout control unit 26 image synthesis unit 36 route search processing unit 38 guidance route memory 42 guidance route drawing unit

Claims (4)

[Claims] 1. A map data storage means for storing map data including information on whether or not a turn on a road is possible, and a destination and a departure place are determined based on the map data stored in the map data storage means. A navigation device, comprising: route search means for searching for a connecting route while allowing a turn on the road. 2. The map data according to claim 1, wherein the map data stored in the map data storage unit associates a U-turn road provided on the road with an independent link, and the link is determined by the route search unit. A navigation device, which is included in a route search target. 3. The map data according to claim 1, wherein the map data stored in the map data storage means includes information indicating whether or not a U-turn is possible on a road as attribute information of a node. A navigation device characterized in that a node having the propriety or not as attribute information is included in a route search target. 4. A map data storage means for storing map data including information on whether or not a turn on a road is possible, and a map display of a predetermined range is performed based on the map data stored in the map data storage means. And a map display means for displaying a predetermined mark at a turnable position on a road.