JPH10333559A - On-vehicle navigation device and map data storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle navigation device capable of easily and precisely recognizing a prefecture where a vehicle exists at present with the navigation device itself and a map data storage medium used in the navigation device. SOLUTION: Roads are recorded in a CD-ROM 1 as connected ones of plural nodes that their longitude and latitude are known, and the additional data showing the prefectures that the nodes exist are added to respective nodes. The control part 15 of the navigation device 10 main body detects the present position of the vehicle from signals inputted form a GPS receiver 3 and a self- contained navigation sensor 4, and corrects a detected position by map matching. At this time, the control part 15 recognize the prefecture that the vehicle exist by the additional data referring to the nodes answering to the road where the vehicle is traveling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle navigation device for detecting a position of a vehicle, displaying a map image around the vehicle on a display device, and guiding the vehicle to a destination, and used in the in-vehicle navigation device. A map data storage medium to be stored.

[0002]

2. Description of the Related Art An on-vehicle navigation device is a map data storage device such as a CD-ROM or an IC card storing map data, a display device such as a liquid crystal display, a gyro, a GPS (Global Positioning System).
And a vehicle movement detection device that detects the current position and current direction of the vehicle such as a mileage sensor, reads map data including the current position of the vehicle from a map data storage device, and detects a vehicle position based on the map data. The surrounding map image is drawn on the display screen, the vehicle position mark (location) is displayed on the map image, and the map image is scroll-displayed according to the movement of the vehicle, or the map image is fixed on the screen and the vehicle is By moving the position mark, the user can see at a glance where the vehicle is currently traveling.

[0003] In addition, usually, a car navigation system is equipped with a route guidance function that allows a user to easily travel to a desired destination without making a mistake on a road. According to this route guidance function, the lowest cost route from the starting point to the destination using the map data is automatically searched by performing a simulation calculation such as the horizontal search method or the Dijkstra method, and the searched route is guided. The route is stored as a route, and during driving, the guidance route is drawn on the map image in a different color from the other roads and displayed thicker, or displayed on the screen, or a certain distance to the intersection where the vehicle should change the route on the guidance route When the vehicle approaches, the user is guided to the destination by displaying an arrow indicating the course at an intersection where the course on the map image should be changed.

The cost is a value obtained by multiplying a constant according to a road width, a road type (such as a general road or an expressway), a right turn, a left turn, and the like based on the distance, a predicted traveling time of the vehicle, and the like. , The degree of appropriateness as a guidance route is quantified. Even if there are two routes having the same distance, the cost differs depending on whether the user specifies, for example, whether to use a toll road, or gives priority to distance or time.

A map stored in a map data storage device such as a CD-ROM has a longitude width of an appropriate size according to a scale level such as 1/12500, 1/25000, 1/50000, and 1/100000. Roads and the like are stored as a coordinate set of vertices (nodes) represented by longitude and latitude. A road is formed by connecting two or more nodes, and a portion connecting the two nodes is called a road link. The map data includes (1) a road layer including a road list, a node table, an intersection configuration node list, and the like; (2) a background layer for displaying roads, buildings, facilities, parks, rivers, and the like on a map screen; (3) Administrative division names such as municipalities,
It is composed of a character / symbol layer for displaying characters such as road names, intersection names and building names, and map symbols.

[0006]

However, in the conventional on-vehicle navigation device, as described above, the map is divided into rectangular regions of an appropriate size and stored in the map data storage device. No boundaries are shown. For this reason, the navigation device itself cannot accurately know in which prefecture the vehicle is traveling.

If the navigation device itself can know the prefecture where the vehicle is currently located, the user can be automatically provided with sightseeing spots and various events in the prefecture where the vehicle is traveling, Various services can be provided, such as automatically switching to a radio station of the prefecture that broadcasts the same radio program as the radio program that was being heard when entering another prefecture.

It is conceivable that a boundary of a prefecture is represented by a set of nodes whose longitude and latitude are known and stored in a map data storage device so that the boundary of the prefecture can be recognized by the navigation device itself. Can be However, in that case, the boundary line of the prefectures has a complicated shape, so that the amount of data becomes enormous, and it is necessary to calculate by calculation which prefecture the vehicle position is in, which requires a long time for the calculation. Problems arise.

Accordingly, an object of the present invention is to provide an in-vehicle navigation device capable of easily and accurately recognizing a prefecture where a vehicle is currently located, and a map data storage medium used in the navigation device. It is to be.

[0010]

The above-mentioned objects are achieved by a display means capable of displaying a map image, a map data storage means storing map data, a vehicle position detection means for detecting a current position of a vehicle, Control means for reading map data around the current position of the vehicle detected by the position detecting means from the map data storing means and drawing a map image on the display means, wherein the map data storing means A solution is provided by an in-vehicle navigation device, characterized in that the latitude is expressed as a connection of a plurality of nodes with known latitudes, and the data of the node is added with additional data indicating the prefecture where the node is located. .

An object of the present invention is to provide a map data storage medium for storing map data in which a road is represented as a connection of a plurality of nodes having known longitudes and latitudes, wherein the data of the node indicates the prefecture where the node is located. The problem is solved by a map data storage medium to which data is added. Hereinafter, the operation of the present invention will be described.

In the present invention, additional data indicating the prefecture in which the node is located is added to the data of the node constituting the road. Usually, navigation devices
The position of the vehicle is detected based on signals from a GPS receiver, a gyro, a traveling distance sensor, and the like, and the detected position is corrected (map matching) so that the vehicle is located on a road using map data. That is, usually, the on-vehicle navigation device always refers to the data of the node corresponding to the road on which the vehicle is traveling because it is necessary for map matching.

According to the present invention, since the additional data indicating the prefecture where the node is located is added to the data of the node, the navigation device can easily and accurately recognize the prefecture where the vehicle is located from the additional data. it can. The additional data may be added to all nodes included in the map data, or may be added only to nodes near the boundary of the prefecture in order to reduce the amount of data. Alternatively, it may be added only to main roads such as expressways and national roads.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a vehicle-mounted navigation device according to an embodiment of the present invention. Reference numeral 1 denotes a CD-ROM storing map data. The CD-ROM 1 stores a road layer, a background layer, and a character / symbol layer. Details of the road layer will be described later.

Reference numeral 2 denotes a navigation device body 10 to be described later.
Is an operation unit provided with various operation buttons and the like for operating. Reference numeral 3 denotes a GPS receiver that receives a GPS signal transmitted from a GPS satellite and detects the longitude and latitude of the current position. Reference numeral 4 denotes a self-contained navigation sensor. The self-contained navigation sensor 4 includes an angle sensor 4a such as a gyro that detects a vehicle rotation angle, and a traveling distance sensor 4b that generates a pulse for each predetermined traveling distance. Reference numeral 7 denotes a liquid crystal display device.
The display device 7 displays a map around the current position of the vehicle, a guidance route from the departure point to the destination, a vehicle position mark, and other guidance information.

The navigation apparatus main body 10 comprises the following. A map buffer 11 temporarily stores map data read from the CD-ROM 1. Reference numeral 12 denotes an interface connected to the operation unit 2;
Is an interface connected to the GPS receiver 3, and 14 is an interface connected to the self-contained navigation sensor 4.
Reference numeral 15 denotes a control unit. The control unit 15 detects the current position of the vehicle based on various types of information input from the interfaces 13 and 14, and reads map data of a predetermined area from the CD-ROM 1 to the map buffer 11. Or search for an optimal route from the departure place to the destination under the set search conditions.

Reference numeral 17 denotes a map drawing unit for generating a map image using map data stored in the map buffer 11, and reference numeral 18 denotes a VRA for storing the map image generated by the map drawing unit 17.
M. 19 is a VRAM according to an instruction from the control unit 15.
An image reading unit that reads a map image in a range to be displayed on the display device 7 from among the map images stored in the display device 18;
The control unit 15 can smoothly scroll the map image displayed on the display device 7 by controlling the image reading unit 19.

Reference numeral 20 denotes a guidance route storage unit for storing the guidance route searched by the control unit 15, and reference numeral 21 denotes a guidance route drawing unit for drawing the guidance route. The control unit 1 is stored in the guidance route storage unit 20.
5 are recorded from the starting point to the destination. When displaying the map, the guide route drawing unit 21 reads the guide route information (node sequence) from the guide route storage unit 20 and draws the guide route in a color and line width different from those of other roads.

Reference numeral 22 denotes an operation screen generating unit for generating various menu screens (operation screens) according to the operation status, and reference numeral 23 denotes a mark generating unit for generating various marks such as a vehicle position mark and a cursor. Reference numeral 24 denotes an image synthesizing unit, and an image reading unit 19
In the map image read out from the VRAM 18, various marks generated by the mark generation unit 23 and the operation screen generation unit 2
The operation screen generated in step 2, the guidance route drawn by the guidance route drawing unit 21, and the like are superimposed and displayed on the display device 7.

FIG. 2 is a diagram showing the configuration of a road layer in the map data recorded on the CD-ROM 1. The road list RDLT includes, for each road, a road type, the total number of nodes forming the road, and a node table NDT of nodes forming the road.
It consists of data such as the position on B and the width to the next node. Intersection configuration node list CRLT
Is a set of positions on the node table NDTB of the other end node of the link (referred to as an intersection configuration node) connected to the intersection for each intersection on the map. Node table N
The DTB is a list of all nodes on the map, and includes position information (longitude and latitude) for each node, an intersection identification flag indicating whether or not the node is an intersection, and a non-intersection (intersection identification flag is “0”). If it is, it is configured with a pointer or the like indicating the position of the road to which the node belongs on the road list, and additional data indicating the prefecture where the node is located is added to each node.

Hereinafter, the operation of the above-described on-vehicle navigation device will be described. The control unit 15 controls the GPS receiver 3
The current position of the vehicle is detected from the GPS signal received by the GPS and the signal input from the self-contained navigation sensor 4, and the CD-ROM 1
, The map data of the area including the current position of the vehicle is read out to the map buffer 11. Then, the control unit 15 stores the vehicle position detected by the signals input from the GPS receiver 3 and the self-contained navigation sensor 4 with the movement of the vehicle, and stores the vehicle position in the map buffer 1.
Correction (map matching) is performed using the map data read in step 1 so that the vehicle is located on the road.

Then, the control unit 15 controls the display device 7
The vehicle position mark is superimposed and displayed on the map image displayed in, and the vehicle position mark is moved or the map image is scrolled with the movement of the vehicle. In this case, as shown in FIG. 3, since the road R is expressed as a connection of a plurality of nodes N, the control unit 15 performs map matching and detects the vehicle so as to be located on a road link connecting the nodes N. Correct the position. Because it is necessary for this map matching,
The control unit 15 controls each node N of the road R on which the vehicle is traveling.
Is always referred to, and the prefecture where the vehicle is located is recognized from the additional data added to the data of the node N.

In the navigation apparatus according to the present embodiment, when a destination is set by the user at the time of searching for a guidance route, the current position of the vehicle is set as a departure point, and a route with the lowest cost to the destination is searched. To be a guidance route, and all nodes constituting the guidance route are stored in the guidance route storage unit 20. Then, the guidance route is superimposed on the map image drawn on the display device 7 and displayed, and guidance on the traveling direction and the like is provided to the user as the vehicle moves.

As described above, even when the vehicle is traveling along the guidance route, the control unit 15 detects the vehicle position based on signals input from the GPS receiver 3 and the self-contained navigation sensor 4,
The detected vehicle position is corrected by map matching.
At this time, the control unit 15 recognizes the prefecture where the vehicle is located from the additional information added to the node data of the road on which the vehicle is traveling.

In the on-vehicle navigation device according to the present embodiment, the prefecture where the vehicle is located is always recognized by the additional data added to the node data.
Various databases can be created in the D-ROM 1 for each prefecture and various services can be realized. For example, by recording the frequency of a radio station that broadcasts the same program on a CD-ROM 1 for each prefecture, it is possible to connect to an audio system having a radio tuner controllable by a navigation device and to travel a long distance. It is possible to automatically switch to a broadcasting station broadcasting the same program. Also, if sightseeing spots and events for each prefecture are stored in the CD-ROM 1 as a database,
It is possible to automatically provide the user with the sightseeing spots and events of the prefecture where the vehicle has entered.

In the above example, the additional data indicating the prefecture is added to all the nodes. However, the additional data may be added only to main roads (expressways and national roads). Thereby, an increase in the number of data can be suppressed. Further, as shown in FIG. 4, the data indicating the prefecture may be added to only the nodes near the boundary. In the map data shown in FIG. 4, data indicating a boundary is added to a node Ni located at a boundary between prefectures, and nodes Ni-1 and Ni + 1 sandwiching this node Ni are respectively connected to a node Ni-1. , Ni + 1 are added with additional data indicating the prefecture, and the other nodes N0 are not added with additional data indicating the prefecture. When the control unit 15 detects the node Ni to which the additional data indicating the boundary is added while traveling on the road, the node N in front of the node Ni is detected.
Examine the additional information of i + 1 to detect the prefecture where the vehicle is located.

In the above embodiment, the case where the storage medium for storing the map data is a CD-ROM has been described. However, the map data storage medium is not limited to the CD-ROM, but may be an IC card, a DVD ( Digital Versatil
e Disk) -ROM or other storage media. Also, in the above-described embodiment, a case has been described in which data indicating a prefecture is added as additional data. You may make it recognizable.

[0028]

As described above, according to the on-vehicle navigation device of the present invention, the map data storage means expresses a road as a connection of a plurality of nodes whose longitude and latitude are known. Since the additional data indicating the prefecture where the node is located is added to the data of the node, the navigation device itself can easily and accurately recognize the prefecture where the vehicle is currently located. This enables new services such as automatically providing information on sightseeing spots and events in the prefecture where the vehicle is traveling.

According to the map data storage medium of the present invention, a road is represented as a connection of a plurality of nodes having known longitudes and latitudes, and the data of the node includes additional data indicating the prefecture where the node is located. With the addition, the navigation device having the map data storage medium of the present invention can easily and accurately recognize the prefecture of the current position by the navigation device itself.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a configuration of a road layer recorded on a CD-ROM.

FIG. 3 is a schematic diagram showing a road and a plurality of nodes indicating the road.

FIG. 4 is a schematic diagram illustrating an example in which additional data is added only to a node near a boundary between prefectures.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CD-ROM 2 Operation part 3 GPS receiver 4 Self-contained navigation sensor 7 Display device 11 Map buffer 12-14 Interface 15 Control part 17 Map drawing part 18 VRAM 19 Reading-out part 20 Guide route storage part 21 Guide route drawing part 22 Operation screen Generation unit 23 Various mark generation units 24 Image synthesis unit

Claims (4)

[Claims] 1. A display device capable of displaying a map image, a map data storage device storing map data, a vehicle position detection device detecting a current position of a vehicle, and a current vehicle position detected by the vehicle position detection device. Control means for reading map data around a position from the map data storage means and drawing a map image on the display means, wherein the map data storage means connects roads with a plurality of nodes of known longitude and latitude. Wherein the data of the node is added with additional data indicating the prefecture where the node is located. 2. A map data storage medium for storing map data representing a road as a connection of a plurality of nodes having known longitudes and latitudes, wherein additional data indicating the prefecture where the node is located is added to the data of the node. A map data storage medium characterized by being stored. 3. The map data storage medium according to claim 2, wherein the additional data is added only to a node near a boundary between prefectures. 4. The map data storage medium according to claim 2, wherein said additional data is added only to a node of a main road.