JPH11351896A - Route guiding device and method and map database storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire path information used for guidance without referring to a map in a route guiding device utilizing a map database. SOLUTION: A route calculating means 101 calculates a route using a map storage means 106 and expresses it in a row of identifiers of a road link for constituting the route. A current position detection means 102 detects the current position of a traveling body that mounts the device and expresses it with the identifier of the road link. A guidance-controlling means 104 selects the identifier of the road ink used for creating guidance information from the above path and passes it to a road name acquisition means 103. The road name acquisition means 103 acquires a road name corresponding to the identifier of the above road link and returns it to the guidance control means 104. The guidance control means 104 creates guidance information for driving along the above route from the above current position using the above road name, passes it to a display means 105, and displays the guidance information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for a route guidance device and its method in a map database utilization system such as a car navigation system, and a database related thereto.

[0002]

2. Description of the Related Art In general, a car navigation device that is widely used as a device for performing route guidance searches a route based on a map database in accordance with designation of a destination, a waypoint, and the like by a user, and can run according to the searched route. To
Guide information according to the driving of the car is created based on a map database, and is displayed on a screen or output as sound. Reading of data from the map database is performed once for the entire route when searching for a route, but when displaying guidance information, it is performed again each time the guidance information changes due to changes in the position of the car etc. It is.

[0003] For example, FIG.
FIG. 9 is a block diagram in Japanese Patent Application Publication No. 9 "Map information display device and traveling body display device for moving object and audio output device for route guidance device". This device is a car navigation device that outputs character information relating to the current position of a moving object on a screen and as audio guidance information while traveling. At this time, the character string extraction circuit 7 reads character string information from the map database stored in the CD-ROM mounted on the disk drive 5 through the CD-ROM reading unit 6. That is, every time a new character string is to be displayed, data for creating the content to be displayed is read from the medium storing the map database.

[0004]

Many car navigation systems use a CD-ROM or DVD-ROM as a medium for storing a map database. These media take time to read data. Therefore, an increase in the number of accesses to the map database causes a delay in operation.

The present invention uses an identifier of a road link constituting a route when expressing a route used for guidance, and uses an identifier of a corresponding road link when expressing a current position; By making it possible to obtain the road name used for route guidance from the identifier of the road link, the route is configured without actually reading the data of the road link indicated by the identifier from the map database stored in the medium. It is possible to display guidance information by road name,
An object of the present invention is to reduce a delay in operation in displaying guidance information.

[0006]

In order to solve the above problems, the present invention firstly provides a route calculating means for acquiring a route to be guided and outputting a sequence of identifiers of road links constituting the route; A current position detecting means for detecting a position where a moving object equipped with a route guidance device is present and outputting an identifier of a road link corresponding to the position, and acquiring a road name of a road to which the road link belongs from the identifier of the road link. The road name acquisition means to be output and output, the current position obtained by the current position detection means, and the route obtained by the route calculation means are input, and the road links constituting the route are used to generate guidance information. The one that acquires the road name is selected based on the current position, the road name acquisition means is given an identifier of the road link to acquire the road name, and the current position, the route, and the road name are acquired. A guidance control means for generating guidance information to guide a movable body for mounting Luo the navigation system,
Display means for displaying guidance information created by the guidance control means, wherein a road name obtained from each identifier of a road link constituting a route can be displayed as information for guidance. .

[0007] This makes it possible to generate guidance information based on the road name acquired from the identifier of the road link, and it is possible to display the guidance information without newly reading from the map database. Things.

Second, in the route guidance device, when the road name obtaining means obtains the road name from the road link identifier, the road link identifier is converted to generate the road name. A road name of a road to which a road link belongs can be obtained without referring to a database describing a relationship between a road identifier and a road name.

Thus, when the road name obtaining means obtains the road name from the identifier of the road link, there is an effect that reading of another database becomes unnecessary.

Thirdly, the route guidance device includes a road correspondence table storing means for storing a correspondence between the road identifier and the road attribute, and the road name acquiring means obtains the road identifier from the road link identifier. By referring to the road correspondence table stored in the road correspondence table storage means on the basis thereof, a road attribute can be obtained from the identifier of the road link and a road name can be created based on the attribute. is there.

Thus, when the road name obtaining means obtains the road name from the road link identifier, it is difficult to directly describe the road link identifier, such as the road common name, which is a character string unique to the road. This also has the effect that it can be used.

Fourth, in the route guidance device, the road name acquiring means determines whether to refer to the road correspondence table when acquiring the road name from the identifier, based on a part of the identifier of the road link, A road name can be generated based on the information.

Thus, when the road name obtaining means obtains the road name from the road link identifier, it is possible to use only the information obtained from the road link identifier, and when it is necessary to refer to the database. This has the effect of being able to deal with

Fifth, in the route guidance device, the road name acquiring means can use a part of the identifier of the road link used in determining whether to refer to the road correspondence table as an attribute. is there.

Thus, the value for determining the method of obtaining the road name from the identifier of the road link by the road name obtaining means can be used for obtaining the road name, and the data indicating the attribute and the storage method of the attribute are shown. This has the effect of sharing data and saving data size.

Sixth, in the route guidance device, the field of the identifier of the road link read when the road name acquisition means determines whether or not to refer to the road correspondence table expresses two or more types of attributes, and The method for distinguishing those attributes is to be a field with the minimum number of bits to express at the same time.

Thus, when the road name obtaining means determines the road from the identifier of the road link, the attribute can be extracted from the data read at the time of determining the road name obtaining method, and the efficiency of using the data read from the map database is improved. This is an effect that can be performed.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. The present invention is not limited to these embodiments at all, and can be implemented in various modes without departing from the gist thereof.

(Embodiment 1) FIG. 1 is a block diagram showing an embodiment of the route guidance apparatus according to the present invention. 10
Reference numeral 1 denotes a route calculation unit that obtains a route used for guidance. This can be a search from a map database,
The route may be manually designated by the user, existing route data may be used, or a route may be obtained by another device and the result may be received by communication. The route calculating means (101) passes the acquired route to the guidance control means (104) in the form of a column of identifiers of road links constituting the route. In the present embodiment, it is assumed that a departure point and a destination of a route are input, and a route search is performed using a map database stored in a map storage means (106).

Reference numeral 102 denotes a current position detecting means for checking a position on a map of a moving body on which the apparatus is mounted. this is,
Artificial satellites and various communication facilities (transmission facilities for wireless telephones, facilities for transmitting location information for car navigation systems, etc.)
The search may be performed by a signal transmitted from a vehicle, a self-contained position search using a travel record measured by a self-contained navigation sensor such as a gyro or a speed sensor and a map, or may be manually specified by a user. The current position detecting means (102) passes the detected current position to the guidance control means (104) using the identifier of the corresponding road link.

In the present embodiment, it is assumed that the current position of the moving object is detected by position measurement by GPS and map matching on a map database stored in the map storage means (106). Also, the moving body on which the device is mounted moves on the route calculated by the route calculation means (101), and the identifier of the road link output by the current position detection means (102) is the route output by the route calculation means (101). Is included in the column of road link identifiers indicating

Reference numeral 103 denotes a road name obtaining means for obtaining a road name from the identifier of the road link to which the road link belongs by performing a predetermined process on the input identifier of the road link. In that case, the road identifier may be taken out from the road link identifier and converted to be used as the road name, or the database identifier in which the road identifier and the road name are associated with each other may be used. Thus, a road name may be obtained. The acquired road name is output in the form of a character string and passed to the guidance control means (104). In the present embodiment, it is assumed that the road number is represented by a numeral, and the one obtained by connecting the "line" is used as the road name.

Reference numeral 104 denotes guidance control means for creating guidance information for proceeding from the current position obtained by the current position detection means (102) in accordance with the route obtained by the route calculation means (101). At this time, first, the order of the current position obtained by the current position detection means (102) on the route obtained by the route calculation means (101) is obtained. Then, a road link for obtaining a road name is selected from the routes obtained by the route calculating means (101) based on the route link. The identifiers of the road links for which the road names are to be obtained are passed one by one to the road name obtaining means (103) to obtain the road names and create the guidance information. The guidance information may be a content that displays only the road name of the road to which the road link to which the moving body equipped with the device goes next belongs,
The content of displaying the road names of all road links that pass in the future may be displayed, or the content of displaying the road names including the roads that have already been passed may be displayed.

In the present embodiment, one road name is output for each section having the same road name from all the road links constituting the route, and the road name including the current position is indicated by the road name. A method of attaching a mark shall be adopted.

Reference numeral 105 denotes display means for displaying the guidance information created by the guidance control means (104). FIG. 2 is an example of a display. The display may be performed by displaying a map as shown in FIG. 2-1 on a screen and displaying a road name on the map.
-2 It is also possible to display the road names of the roads that pass separately from or without a map like a table,
Alternatively, a method of expressing the names of the roads that pass through by voice may be used. When a table of road names is used, the vertical dimension of the table may be changed according to the number and length of road links belonging to each road as shown in FIG. And additional information indicating the length may be added and output. In the present embodiment, as shown in FIG. 2-2, a method of displaying a table of road names of roads that pass through is adopted.

Reference numeral 106 denotes a map storage unit for storing a map database. Although not present in the claims, in the present embodiment, the route calculation means (101) and the current position detection means (102) are provided to use the map database.

A road database is stored in the map database stored in the map storage means (106). The road network is composed of road links and road nodes. A road is created by collecting multiple road links. Road links constituting one road are road links called by the same name. Road links called by the same name may be classified into a plurality of roads.
At that time, the same road link cannot belong to the plurality of roads.

FIG. 3 shows an example of a road network included in a map database, road links constituting the road network, and roads formed by the road links. It is assumed that a road network as shown in FIG. 3-1 is stored in the map database. The links constituting this road network are road links. FIG. 3B is an example of a road in which road links are collected. In each of FIGS. (1) to (3), a portion represented by a solid line is a road.

Each road link is given an identifier that is unique in the map database. FIG. 4 shows this state. Reference numeral 401 denotes a map database stored in the map storage means (106). The map database (401) stores road links (402). The road nodes used to construct the road network may be stored in the map database (401) separately from the road links (402), or may be described in the road links (402). Further, other data such as facilities, water systems, railways, etc. may be stored.

Reference numeral 402 denotes a road link constituting a road network stored in the map database (401). Each road link (402) stores an identifier (403) of the road link. In one map database (401), there are no more than two road links (402) having the same road link identifier (403).

Reference numeral 403 denotes a road link identifier. Stored one by one for road links. This is the road link (4
02) can be taken out by the method determined from the above.
The road link identifier (403) is the road identifier (40).
3a) and a unique number within the same road (403b)
It is composed of

The road identifier (403a) is an identifier indicating the road to which the road link belongs. For example, a combination of a road type, a line number, a prefecture code, and the like may be used as the identifier. A code that is mechanically uniquely assigned to each road may be given in advance, and the code may be used as a road identifier. Detailed data such as a road name may be used as a road identifier as it is. For road links that do not belong to a road,
An identifier indicating this is stored as a road identifier.

A unique number (403) within the same road
b) is set to a value that can uniquely specify an identifier (402) of a road link belonging to the same road in the map database (401).

Even when the route calculating means (101) and the current position detecting means (102) operate without the need for the map database (106), the above-mentioned configuration of the map database is used as a common background for each means. And

FIG. 5 is a flowchart showing the operation of the route guidance apparatus according to the first embodiment. The operation is described below. The route calculation means (101) receives the input of the departure place and the destination of the route search, reads the road network stored in the map database from the map storage means (106), and determines the route from the departure place to the destination. The search is performed, and the search result is passed to the guidance control unit (104) as a column of the identifiers of the road links included in the route (501).

The current position detecting means (102) detects the current position of the moving object equipped with this device by using GPS, and the detected position is mapped to a map database stored in the map storage means (106). The link is converted into a corresponding road link by matching, and the identifier of the road link is passed to the guidance control means (104) as a detection result (502).

The guidance control means (104) selects road links to be used for creating guidance information from the column of road link identifiers output from the route calculation means (101), and sequentially identifies each road link identifier in the road. Name acquisition means (103)
Pass to. The road name acquisition means (103) receives the link identifier from the guidance control means (104), acquires the road name corresponding to the identifier, and provides the guidance control means (104).
(503).

The guidance control means (104) creates guidance information for traveling along the route calculated by the route calculation means (101) from the current position detected by the current position detection means (102). At that time, the generated guidance information is passed to the display means (105) using the road name output by the road name acquisition means (103). In the present embodiment,
A flag indicating the current position is provided for each road name, and the flag is set for the corresponding road name obtained from the identifier of the road link of the current position detected by the current position detecting means (102). Represents the current position (504). The display means (105) outputs the guidance information output by the guidance control means (104) (505).

As described above, in the present embodiment, when the guidance control means (104) creates guidance information from the route and the current position represented by the column of the road link identifier (403), the road link The road name obtaining means (10) is obtained from the road identifier (403a) stored in the identifier (403).
By acquiring the road name, the name of the road to which the road link representing the route belongs is assigned to the map database (4).
No. 01) can be obtained and guidance information can be created without referring to it, and its practical effect is great.

(Embodiment 2) A flowchart, an example, and an operation of the route guidance method according to the second embodiment are the same as those of the first embodiment. (Embodiment 3) A flowchart, an example, and an operation of a route guidance method stored in a recording medium according to claim 3 are as follows.
According to Embodiment 1. (Embodiment 4) The configuration diagram and the flow chart of the route guidance device according to the fourth embodiment conform to the first embodiment.

FIG. 6 is a diagram of road link identifiers according to the fourth embodiment. Reference numeral 601 denotes a road link identifier that uniquely defines a road link in the map database. The road link identifier (601) is the road identifier (601).
a) and a unique number (601b) within the same road.

Reference numeral 601a denotes a road identifier indicating the road to which the road link belongs. Road identifier (601a)
Is not only uniquely assigned to each road, but also a road name used for guidance information can be created based on the value. For example, there is a case where a number is assigned to each road and the number is generally known, or a case where the road name is directly stored in the identifier of the road.

The road identifier (601a) can be used in a plurality of fields when a road can be specified by combining a plurality of attributes. For example,
For example, a combination of a road type, a line number, a prefecture code, or the like is used as an identifier.

In this embodiment, the identifier of the road (601
a) is the road type (601c) and the road number (601d)
It is composed of For example, this corresponds to a case where a route number is set for each road type in the road network. When the road identifier (601a) is divided into a plurality of fields and used as described above, the dividing method is applied to all the road links stored in the map database in a unified manner. It is also assumed that the method of division is known in advance.

It is also assumed that 0 is not used as a road identifier. For a road link that does not belong to any road, 0 is stored as a road identifier to indicate that it does not belong to any road.

601b is the identifier of the same road (601a)
Is a unique number within the same road that is uniquely given to a road link in the same map database. The identifier (6) of the road link having a different road identifier (601a)
01) may have the same number.

The road name obtaining means (103) converts the input road link identifier (601) from the road identifier (6).
01a), and a road name is created and output from the road identifier (601a).

In the present embodiment, the road link identifier (601) is treated as a bit string, a certain number of high-order bits are extracted, and the extracted bits are used as the road identifier (601).
a). A fixed value is predetermined for the number of bits of the road identifier. From the road identifier, the road type (601
c) and the road number (601d) are obtained in the same manner. The road type name corresponding to each road type is stored in the road name obtaining means (103).

When the road name obtaining means (103) receives the road identifier (601), the road name obtaining means obtains the road identifier (601a), and further obtains the road type (60).
1c) and the road number (601d). First, a road type name corresponding to the road type (601c) is obtained. Next, a character string that becomes "X-line" when the road number is X is created. This is connected to the character string of the road type name to form a road name. For example, in the case of the highway No. 1, a character string of "highway" is acquired from the road type of the expressway, a character string of "highway 1" is created from the road number 1 indicating the highway 1, and the two are connected. This is output as a character string of "Highway No. 1" as a road name.

When the value of the road identifier is 0, the character string "general road" is output as the road name. The place where the road identifier (601a) is located in the road link identifier (601) may be higher, lower, middle, or plural. In addition to the division by bits, the road number and the unique number within the road may be distinguished by an arbitrary decimal system, such as by the digit when the identifier of the road link is interpreted in decimal. The same applies to the road type (601c) and the road number (601d) in the road identifier (601a).

The guidance control means (104) uses the road name acquired from the identifier of each road link of the route by the road name acquisition means (103) to create the guidance information as described in the first embodiment. .

As described above, in the present embodiment, when the guidance control means (104) creates guidance information from the route or the current position represented by the column of the road link identifier (601), the road link information is generated. The road identifier (601a) stored in the identifier (601) is stored in the road name obtaining means (103).
Is converted to obtain road names, so that guidance information is created by obtaining the name of the road to which the road link representing the route belongs without referring to the map database and without referring to other correspondence tables. The practical effect is great.

(Embodiment 5) The flowchart, examples, and operations of the route guidance method according to the fifth embodiment are the same as those of the fourth embodiment.

(Embodiment 6) A flowchart, an example, and an operation of a route guidance method stored in a recording medium according to a sixth embodiment are the same as those of the fourth embodiment.

(Embodiment 7) FIG. 7 is a block diagram of a route guidance apparatus according to a seventh aspect. 101-106
Is based on FIG. However, the road name acquisition means (10
3) refers to the road correspondence table storage means (701) when determining the identifier of the road link.

Reference numeral 701 denotes a road correspondence table storing a road correspondence table for recording the correspondence between the road identifier stored in the road link identifier and the road name used for display by the display means (105). Means.

FIG. 8 shows an example of a road link identifier and a road correspondence table stored in the road correspondence table storage means in the seventh embodiment. A road number is assigned as a road identifier to a road to which a road link constituting the road network of the map database stored in the map storage means (106) belongs. This road number does not need to be convertible to a road name that can be used for guidance information. It is assumed that 0 is not used for the road number. For a road link that does not belong to any road, 0 is stored as a road number, indicating that it does not belong to any road.

Reference numeral 801 denotes a road correspondence table stored in the road correspondence table storage means (701). Road correspondence table (80
In 1), a set of the road numbers of all the roads to which the road links constituting the road network of the map database stored in the map storage means (106) belong with the attribute of the road indicated by the road number is set. Is stored.

801a is a road number stored in the road correspondence table (801). A road number 0 indicating a road link that does not belong to a road is a road correspondence table (80
It may or may not be stored in 1). In this embodiment, it is assumed that the road number 0 is not stored. A road number other than the road number of the road to which the road link stored in the map database belongs may be stored.
A plurality of one road number (801a) must not be stored.

Reference numerals 801b and 801c denote road names and road types, which are attributes of the road. In the present embodiment, the road common name (801b) and the road type (801c) are stored.
3) is determined according to the method of obtaining the road name. All road attributes necessary for the road name obtaining means (103) to obtain the road name are as shown in the road correspondence table (8).
01) must be stored. One of the attributes stored in the road correspondence table (801) does not need to be the road name as it is. Road name acquisition means (103)
Attributes not used by may be included. Further, with respect to a plurality of road numbers (801a), the values of the corresponding attributes may match. When storing the road number 0 indicating that the road link does not belong to the road in the road correspondence table (801), the road name obtaining means (103) uses the road attribute based on the road attribute corresponding to the road number. The attribute is set so that a road name for creating guidance information indicating that the link does not belong to the road can be obtained.

Reference numeral 802 denotes a road link identifier. The road link identifier (802) includes a road number (802a), which is a road identifier, and a unique number (802b) for the same road. 802a is a road number which is an identifier of the road. It corresponds to the road number (801a) stored in the road correspondence table (801). 802b is a unique number on the same road. Same road number (8
02a) have different values between road links.

When the road link identifier (802) is input, the road name obtaining means (103) obtains the road number (802a) therefrom, and searches the road correspondence table (801) for the same road number (801a). , The road common name (801b) stored corresponding thereto is acquired, and this is output as the road name.

When the identifier of the road link is inputted, the road name obtaining means (103) judges whether the road link does not belong to the road or not. Returns the character string "road" as the road name. This may be a character string such as "none", or if the number of characters in the character string can be freely adjusted, the number of characters is set to 0.
Alternatively, if a method of passing a character string pointer is used, a null pointer may be passed. Display means (10
When 5) returns a character string other than a character string that can be used as it is for display, the guidance control means (104) replaces it with a character string such as "general road" or "unnamed". When the road correspondence table (801) corresponds to the road identifier 0,
Ordinarily, the road name corresponding to the road identifier 0 may be obtained. First, a line having a road number of 0 may be searched from the road correspondence table, and if it does not exist, the process for the road number 0 may be performed again.

As described above, in the present embodiment, when the guidance control means (104) creates guidance information from the route and the current position represented by the column of the road link identifier (802), the road link From the road number (802a) stored in the identifier (802), the road name obtaining means (103) uses the road correspondence table (801) to identify the road alias (801b).
By obtaining, the guidance information can be created even when the name of the road to which the road link representing the route belongs cannot be stored in the identifier of the road, and the practical effect is large.

(Embodiment 8) The flowchart, examples, and operations of the route guidance method according to the eighth embodiment conform to those of the seventh embodiment.

(Embodiment 9) A flowchart, an example, and an operation of a route guidance method stored in a recording medium according to a ninth embodiment are the same as those of the seventh embodiment.

(Embodiment 10) A block diagram of the route guidance apparatus according to the tenth embodiment is the same as that of FIG. 7 of the seventh embodiment. However, the road name obtaining means (103) determines whether to refer to the road correspondence table based on the value of the identifier of the road link, and then obtains the road name based on the determination.

FIG. 9 is a diagram showing an example of a road link identifier and a road correspondence table stored in the road correspondence table storage means in the tenth embodiment. The roads to which the road links constituting the road network of the map database stored in the map storage means (106) belong are classified into two types: those whose road names can be expressed by road numbers and those whose road names cannot be expressed. For these two types of roads, road numbers are set independently of each other. A road whose road name can be represented by a road number is a road maintained by a number, such as a national road or a prefectural road. At this time, those line numbers are used as the road numbers. The road name is also created from the line number.

The roads whose road names cannot be represented by road numbers are roads that use place names as road names, for example, Tokaido, Tomei Expressway, Tsunashima Kaido, Hongo-dori. For those roads, a road number is uniquely assigned to each road. The correspondence between the road number and the road name can be found in the road correspondence table (90
Performed in 1).

In this embodiment, first, it is assumed that a road whose road name can be represented by a road number can be specified only by the line number without adding an attribute such as a road type. In both cases, 0 is not used for the road number. 0
Is used as a road number in a road link that does not belong to a road. It is determined in advance whether a road link that does not belong to a road is treated as either of them. In the present embodiment, it is assumed that a road name is treated the same as a road that can be expressed by a road number.

Reference numeral 901 denotes a road correspondence table stored in the road correspondence table storage means (701). Road correspondence table (90
Among the roads to which the road links constituting the road network of the map database stored in the map storage means (106) belong, the road name acquisition means (10) includes:
In 3), when a road name is acquired from an identifier of a road link, a set of a road number of a road using a road correspondence table (901) and an attribute related to the road indicated by the road number is stored.

Reference numeral 901a denotes a road number stored in the road correspondence table (901). The road number (903b) of the road link that does not refer to the road correspondence table (901) is stored in the road correspondence table (9).
01) need not be stored. A road number other than the road number of the road to which the road link stored in the map database belongs may be stored. A plurality of one road number (901a) must not be stored.

Reference numerals 901b and 901c denote a road common name and a road type, which are attributes of the road. In the present embodiment, the road common name (901b) and the road type (901c) are stored.
3) is determined according to the method of obtaining the road name. All road attributes necessary for the road name obtaining means (103) to obtain a road name are as shown in FIG.
01) must be stored. One of the attributes stored in the road correspondence table (901) does not need to be the road name as it is. Road name acquisition means (103)
Attributes not used by may be included. Also, for a plurality of road numbers (901a), the values of the corresponding attributes may match.

The identifier of the road link refers to the identifier (90) referring to the road correspondence table (901) when acquiring the road name.
2) and those not referred to (903). To distinguish them, the identifier of the road link (902 or 903)
Use the value obtained by performing a specific process.
In order to obtain the value, one specific bit of the road link identifier (902 or 903) may be used, or a plurality of bits may be used and each bit pattern represented by the bit pattern may be used for either of them. You can sort them out,
A specific digit or a plurality of digits may be converted into a notation such as a decimal notation and used as a code therefor.

In this embodiment, it is assumed that the identification is made by the value of the first bit of the identifier of the road link. The first bit (902a) of those that refer to the road correspondence table is 1, and the first bit (903a) of those that do not refer to it is 0.

Reference numeral 902 denotes a road link identifier which refers to the road correspondence table (901) stored in the road correspondence table storage means (701) when the road name acquisition means (103) acquires the road name. This is composed of a bit (902a) designating a reading method, a road number (902b), and a unique number (902c) within the same road.

The road number (902b) is stored in the road correspondence table (9
01) corresponding to the same road number (901a).

Reference numeral 903 denotes a road link identifier that does not refer to the road correspondence table (901) stored in the road correspondence table storage means (701) when the road name acquisition means (103) acquires the road name. This is composed of a bit (903a) designating a reading method, a road number (903b), and a unique number (903c) within the same road.

By converting the road number (903b),
The road name is obtained. A road number (902b) when referring to the road correspondence table and a road number (90
3b), the same number may exist, or the storage method for storing the identifier in the road link identifier (902 or 903) may be different.

When the most significant bit (902a) of the input road link identifier is 1, the road name acquiring means (103) refers to the road link identifier (902) by referring to the road correspondence table. It is determined that the identifier is the identifier of the road link belonging to the road for which the road name is to be obtained. Then, the road number (902b) is obtained from the road link identifier (902).
Then, the road correspondence table (901) stored in the road correspondence table storage means (701) is checked, and the road correspondence table (901) is stored in the same road number (902b) as the road number (902b) stored in the road link identifier (902). The corresponding road common name (901b) is obtained and output as a road name.

When the most significant bit (903a) of the road link identifier is 0, the road link identifier (9
03) is determined to be the identifier of the road link belonging to the road for which the road name is acquired without referring to the road correspondence table (901). Then, a road number (903b) is obtained from the road link identifier (903) and converted to generate a road name, which is output as a road name. However, when the road number is 0, “general road” is output as a road name.

As described above, in the present embodiment, when the guidance control means (104) creates the guidance information from the route and the current position represented by the column of the identifier of the road link, the identifier (902) of the road link is used. , 903), the road name obtaining means (103) obtains the road name by performing a certain process. When the road name obtaining means (103) obtains the road name from the road link identifier (902, 903), first, the road link identifier (902, 903)
(902a, 903)
a) is obtained, and the road name obtaining means (1)
03) is a road correspondence table (90) based on the road number (902b).
Refer to 1) to get the road common name (901b) or
The road name obtaining means (103) converts the road number (903b) to obtain the road name, and determines and executes it.

Thus, the name of the road to which the road link representing the route belongs can be obtained without referring to the map database to create the guidance information. At this time, the road name is stored in the identifier of the road. For those that cannot, the road name can be obtained by using the road correspondence table, and the practical effect is great.

(Embodiment 11) The flowchart, examples, and operations of the route guidance method according to the eleventh embodiment are the same as those of the tenth embodiment.

(Embodiment 12) A flowchart of a route guidance method stored in a recording medium according to claim 12,
The working examples and operations are in accordance with the tenth embodiment.

(Thirteenth Embodiment) A block diagram of a route guidance apparatus according to a thirteenth embodiment is the same as that of the tenth embodiment shown in FIG.

FIG. 10 is a diagram showing an example of a road link identifier and a road correspondence table stored in the road correspondence table storage means according to the thirteenth embodiment.

In this embodiment, the map storage means (10
Roads to which the road links constituting the road network of the map database stored in 6) belong are classified into two types: prefectural roads (prefectural roads are hereinafter referred to as prefectural roads) and other roads.

A prefectural road is represented by a combination of a prefectural code and a line number. For the display on the display means (105), a combination of a prefecture name and a line number is used.

For other roads, a road number is uniquely assigned to each road. The association between the road number and the road name is performed in the road correspondence table (1001).

In this embodiment, a road link that does not belong to a road is treated as a road other than a prefectural road.
Is stored.

1001 is a road correspondence table storage means (701)
It is a road correspondence table stored in. Road correspondence table (10
01), the road number (1003a), the common name of the road (100
1b) and the road type (1001c) conform to the road correspondence table (901), the road number (901a), the road common name (901b), and the road type (901c) in the tenth embodiment, respectively.

1002 is an identifier of a road link other than a prefectural road. The identifier (1002) of the road link includes a code (1002a) indicating a road other than the prefectural road, and a road number (1002).
b) and a unique number (1002c) within the road. The code (1002a) that indicates other than the prefectural road is
These are 2 bits corresponding to the upper 2 bits of the prefectural code (1003a) of the identifier (1003) of the prefectural road link.

The road number (1002b) is an identifier of a road that uniquely specifies a road in a set of roads other than the prefectural road. For road links that do not belong to a road, the road number is 0
To All road numbers other than 0 are in the road correspondence table (100
This corresponds to the road number (1001a) stored in 1).

Reference numeral 1003 denotes an identifier of a prefectural road link. The road link identifier (1003) is composed of a prefecture code (1003a), a line number (1003b), and a unique number (1003c) within the road. The prefecture code (1003a) is a code that associates a number from 1 to 47 with each of 47 prefectures.
Allocate a bit field for bits. Route number (1
003b) is a number assigned to a road of a prefectural road independently in each prefecture. This number is generally known, and is displayed as a road name to serve as guidance information. By combining the prefecture code (1003a) and the route number (1003b), it becomes a road identifier that uniquely identifies the road within the set of prefectural roads. Unique number (1001
c) uniquely defines each road link in a set of road links storing the same prefecture code (1003a) and line number (1003b) in the identifier (1003). Since the prefecture code is from 1 to 47,
Prefectural code which expressed it with 6 bits (1003a)
The upper two bits of “1” are “00”, “01”, and “10”. Therefore, in the identifier (1002) of the road link of the road other than the prefectural road, the value of the code (1002a) indicating the non-prefectural road, which is the two bits located at the same position as the upper two bits of the prefectural code (1003a), is set to “11”. .
Thus, the identifier of the prefectural road link (1003)
And the identifier (1002) of the road link other than the prefectural road does not overlap, and by looking at the two bits, the identifier of the road link (1003 or 1003)
2) can determine whether it is a prefectural road or not.

In the present embodiment, it is assumed that these two bits exist at the highest level of the road link identifier (1002 or 1003). This may be in the middle of the road link identifier. Further, in the present embodiment, only one value indicating that the road correspondence table is to be viewed is available among the two possible values of the two bits, but there may be a plurality of values. The length need not be 2 bits. When the road name acquiring means (103) receives the identifier (1002 or 1003) of the road link, it first reads the upper two bits.

The upper 2 bits are "00", "01", and "10".
In either case, it is determined that the link is a prefectural road link. Then, the road name obtaining means (103) reads the upper 6 bits (1003a) including the two bits from the road link identifier (1003) again, interprets it as a prefecture code, and converts this into a prefecture name. Further, the subsequent field is interpreted as a route number (1003b) and connected to the prefecture name, thereby outputting the road name in the form of “○ × prefecture X line”.

If the upper two bits are "11", it is determined that the link is a road link other than a prefectural road. Then, the road name obtaining means (103) determines the identifier (1002) of the road link.
The road number (1002b) is obtained from the
01), the same road number (1001a) is searched, the corresponding road common name (1001b) is acquired, and this is output as the road name.

As described above, in the present embodiment, when the guidance control means (104) creates guidance information from the route and the current position represented by the column of the road link identifier, the identifier (1002) of the road link is used. , 1003), the road name obtaining means (103) obtains the road name by performing a certain process. When the road name obtaining means (103) obtains a road name from the road link identifiers (1002, 1003), first, the road link identifier (100
2, 1003), and interprets it as a code for designating a reading method. According to the value, the road name acquiring means (1) is obtained from the road number (1002b).
03) obtains the road alias (1001b) by referring to the road correspondence table (1001) or the identifier (1) of the road link.
003) including the upper 2 bits of the prefecture code (100
3a) and the route number (1003b) are converted by the road name obtaining means (103) to determine and execute whether or not to obtain the road name.

As a result, the name of the road to which the road link representing the route belongs can be obtained without referring to the map database to create the guidance information. At this time, the road name is stored in the identifier of the road. For those that cannot be obtained, the road name can be acquired by using the road correspondence table, and the area that describes whether to refer to the road correspondence table when acquiring the road name is defined as the area of other attributes. It can be shared, and its practical effect is great.

(Embodiment 14) The flowchart, examples, and operations of the route guidance method according to the fourteenth embodiment are the same as those of the thirteenth embodiment.

(Embodiment 15) A flowchart of the route guidance method stored in a recording medium according to claim 15,
The working example and operation are the same as those in the thirteenth embodiment.

(Embodiment 16) A block diagram of a route guidance apparatus according to a sixteenth embodiment is the same as that of FIG. 7 of the tenth embodiment.

FIG. 11 is a diagram showing an example of a road link identifier and a road correspondence table stored in the road correspondence table storage means according to the sixteenth embodiment.

In this embodiment, the map storage means (10
The road to which the road link constituting the road network of the map database stored in 6) belongs is divided into two types of prefectural roads (prefectural roads are hereinafter referred to as prefectural roads) and other roads according to the road types. .

A prefectural road is represented by a combination of a prefectural code and a line number. For the display on the display means (105), a combination of a prefecture name and a line number is used. Other roads are classified by road type, and a road number is assigned to each road so that it is unique within the road type. The association between the road type and the road number and the road name is performed in the road correspondence table (1001).

In this embodiment, road links that do not belong to a road are treated as other than prefectural roads, and the road number is 0.
Is stored.

1101 is a road correspondence table storage means (701)
This is the road correspondence table stored in. Road correspondence table (1
101), among the roads to which the road links constituting the road network of the map database stored in the map storage means (106) belong, the road name acquisition means (1).
03) uses a road correspondence table (1101) when acquiring a road name from an identifier of a road link, and stores a set of a road type and a road number, and a set of attributes related to the road indicated by the set. . In the present embodiment, sets of road numbers and road types given to roads other than prefectural roads are stored.

1101a and 1101b are road correspondence tables (1
101) is a road type and a road number stored in 101). It is not necessary to store a set of road type and road number of a road link that does not refer to the road correspondence table (1101) in the road correspondence table (1101). That is, in the present embodiment, it is not necessary to store a set of a road type and a road number for a road whose road type is a prefectural road. A combination of a road type and a road number other than the road to which the road link stored in the map database belongs may be stored. Do not store more than one set of road type and road number.

Reference numeral 1101c denotes a road common name which is an attribute of the road. In the present embodiment, the road common name (1101c) is stored, but the type of the attribute is determined according to the method by which the road name obtaining means obtains the road name. All road attributes necessary for the road name obtaining means (103) to obtain the road name are as described above.
01) must be stored. One of the attributes stored in the road correspondence table (1101) does not need to be the road name as it is. Road name acquisition means (10
Attributes not used in 3) may be included. In addition, with respect to a plurality of sets of the road type and the road number, the values of the corresponding attributes may match. A set having a road number 0 indicating that the road link does not belong to the road is set in the road correspondence table (1
101), the road name obtaining means (103) generates a road name for generating guidance information indicating that the road link does not belong to the road based on the road attribute corresponding to the road name. Set attributes so that they can be acquired.

Reference numeral 1102 denotes an identifier of a road link other than a prefectural road. The identifier (1102) of the road link includes a code (1102a) indicating a road other than a prefectural road, and a road type (1102).
b), a road number (1102c), and a unique number within the road (1102d). The code (1102a) indicating other than the prefectural road is two bits corresponding to the upper two bits of the prefectural code (1103a) of the identifier (1103) of the road link in the prefectural road. The road type (1102b) is also the same as the prefecture code (1103).
These are 4 bits corresponding to the lower 4 bits of a).

The road type (1102b) is a code that classifies roads by the type. In the present embodiment, it is assumed that the information is classified into three types: “expressway”, “toll road”, and “general road”. The road number (1102c) is a number that uniquely identifies a road among roads of the same road type (1102b) in a set of roads other than prefectural roads. By combining the road type (1102b) and the road number (1102c), a road identifier is obtained. Road type (1102
If b) is different, the same road number (1102c) may exist. The road type (1102b) corresponds to the road correspondence table (1
103), the road type (1103c) stored in
The road number (1102c) corresponds to the road number (1103a) stored in the road correspondence table (1103).

Reference numeral 1103 denotes an identifier of a prefectural road link. The identifier (1103) of the road link includes a prefecture code (1103a), a line number (1103b), and a unique number (1103c) in the road.

The prefecture code (1103 a) is a code in which numbers from 1 to 47 are associated with each of 47 prefectures, and a 6-bit bit field is assigned.

The route number (1103b) is a number assigned to a prefectural road independently in each prefecture. This number is generally known, and is displayed as a road name to serve as guidance information.

By combining the prefecture code (1103a) and the line number (1103b), it becomes a road identifier for uniquely specifying a road in a set of prefectural roads. The unique number (1103c) is assigned to the same prefecture code (1103c).
3a) and the route number (1103b) are identified by identifiers (110
Each road link is uniquely determined from the set of road links stored in 3).

Since the prefectural code is from 1 to 47, the prefectural code (1103) expressed by 6 bits is used.
The upper two bits of a) are either “00”, “01”, or “10”. Therefore, in the identifier (1102) of the road link of the road other than the prefectural road, the prefecture code (1103) is used.
The value of the code (1102a) that indicates other than the prefectural road, which is the two bits located at the same position as the upper two bits of a), is set to “11”. As a result, the identifier (11
03) and identifiers of road links other than prefectural roads (1102)
And the two bits indicate that the identifier of the road link (1102 or 1
103) can determine whether the road is a prefectural road or not.

In the present embodiment, this prefecture code (1103a) is at the highest level of the road link identifier (1103), and is the identifier (1111) of the road link other than the prefectural road.
In 02), a code (1102a) indicating a road other than a prefectural road and a road type (1102b) are used as identifiers of road links (1102a).
Assume that it exists at the top of 2). This may be in the middle of the road link identifier.

When the road name acquiring means (103) receives the identifier (1102 or 1103) of the road link, it first reads the upper 6 bits.

When the upper 2 bits of the upper 6 bits are "0"
In the case of any one of "0", "01" and "10", it is determined that the road link is a prefectural road. Then, the road name acquiring means (103) interprets the 6 bits as a prefecture code and converts this into a prefecture name. Further, by interpreting the following field as a route number and connecting it to the prefecture name, "○ ×
It is output as a road name in the format of "prefecture X line".

The upper 2 bits of the upper 6 bits are "1".
In the case of "1", it is determined that the link is a road link other than the prefectural road. Then, the road name obtaining means (103) interprets the remaining 4 bits of the upper 6 bits as a road type, and further reads a road number from the road link identifier (1102).
The road correspondence table (1101) stored in the road correspondence table storage means (701) is searched, and the road common name (1101c) corresponding to the same road type (1101a) and road number (1101b) is obtained. Output as road name.

As described above, in the present embodiment, when the guidance control means (104) creates guidance information from the route or the current position represented by the column of the road link identifier, the identifier (1102) of the road link is used. , 1103), the road name obtaining means (103) obtains the road name by performing a certain process. When the road name obtaining means (103) obtains the road name from the road link identifiers (1102, 1103), the road link identifiers (1102, 1102, 1103) are used.
103), the upper 6 bits are obtained, interpreted as a code specifying the reading method, and the value is used to determine the road type (1102b) obtained from the upper 6 bits of the road link identifier (1102) and the newly obtained road. From the number (1102c), the road name obtaining means (103) refers to the road correspondence table (1101) to refer to the road common name (1101).
c) or obtains the prefectural code (1103a) consisting of the upper 6 bits of the road link identifier (1103) and the line number (1103b) from the road name obtaining means (10).
It is determined whether 3) is converted to obtain a road name.

As a result, the name of the road to which the road link representing the route belongs can be obtained without referring to the map database to create the guidance information. At this time, the road name is stored in the identifier of the road. For those that cannot be obtained, the road name can be acquired by using the road correspondence table, and the area that describes whether to refer to the road correspondence table when acquiring the road name is defined as the area of other attributes. The attribute can be shared, and the attribute described in the area read at the time of making the determination does not need to be read again when acquiring the value of the attribute, and the practical effect is large.

(Embodiment 17) The flowchart, examples, and operations of the route guidance method according to the seventeenth embodiment are the same as those of the sixteenth embodiment.

(Embodiment 18) A flowchart of the route guidance method stored in a recording medium according to claim 18,
The working example and the operation are in accordance with the sixteenth embodiment.

(Embodiment 19) FIG. 4 is used as an example relating to a map database stored in a recording medium according to claim 19.

Reference numeral 401 denotes a map database. Road links (402) are stored in the map database. Road nodes used to construct the road network may be stored in the map database (401) separately from the road links (402), or may be described in the road links (402). . Further, other data such as facilities, water systems, railways, etc. may be stored.

A road is created by collecting a plurality of road links. Road links constituting one road are road links called by the same name. Road links called by the same name may be classified into a plurality of roads.
At that time, the same road link cannot belong to the plurality of roads.

Reference numeral 402 denotes a road link constituting the road network stored in the map database (401). Each road link (402) stores an identifier (403) of the road link. In one map database (401), there are no more than two road links (402) having the same road link identifier (403).

Reference numeral 403 denotes a road link identifier. Stored one by one for road links. This is the road link (4
02) can be taken out by the method determined from the above.

The road link identifier (403) is composed of a road identifier (403a) and a unique number (403b) within the same road.

The road identifier (403a) is an identifier indicating the road to which the road link belongs. For example, a combination of a road type, a line number, a prefecture code, and the like may be used as the identifier. A code that is mechanically uniquely assigned to each road may be given in advance, and the code may be used as a road identifier. Detailed data such as a road name may be used as a road identifier as it is. For road links that do not belong to a road,
An identifier indicating this is stored as a road identifier. The number (403b) unique within the same road is set to a value that can uniquely specify the identifier (402) of a road link belonging to the same road in the map database (401).

As described above, in the present embodiment, the identifier (40) of the road link that specifies the road link (402) is used.
3), the road identifier (403a) is stored, and the name of the road can be obtained from the road identifier. Thus, when the road link (402) is represented by the road link identifier (1103), the original road link is obtained. The attribute can be obtained without referring to (402), and the practical effect is great.

(Embodiment 20) FIG.
This is an example of implementation of the database described in. Reference numeral 1201 denotes a database. 1202 is a database (12
01). Each element (120
2) is given an element identifier (1203).
Each element has an attribute used by an application using the database. This attribute may be explicitly described in the element, or may be stored only in the element identifier (1203) by the method described in the present embodiment.

Reference numeral 1203 denotes an element identifier for specifying the element (1202) in the database (1201). This element identifier (1203) may be an identifier used by the database for managing data, an identifier used when an application uses an element stored in the database, or stored as an attribute in the element. Identifier may be used. However, the application using this database must be able to use the element identifier (1203).

The element identifier (1203) is composed of an attribute identifier (1203a) and an element number within attribute (1203b). The attribute identifier (1203a) is an identifier for obtaining an attribute value of the element. Attribute identifier (1
In obtaining an attribute value from 203a), a method that does not refer to a database is used. Element number in attribute (1203
b) is a number for specifying an element (1202) having the same attribute identifier (1203a) in one database (1201).

As described above, in the present embodiment, the element identifier (1203a) is stored in the element identifier (1203) for specifying the element (1202), and the attribute (1203a) can be obtained from the attribute identifier. 1202) by the element identifier (1203), the original element (1202)
Attribute can be obtained without referring to the attribute, and its practical effect is great.

In the present embodiment, the database (1
201) is a map database, an element (1202) is a road link, an element identifier (1203) is an identifier of a road link, an attribute identifier (1203a) is an identifier of a road, and an element number within an attribute (1203b) is the same road. If it is a unique number within, it becomes the database used in the first embodiment.

(Embodiment 21) FIG.
7 is an element identifier of the example of the implementation of the database described in FIG. The relation between the database, the element, and the element identifier is the same as in the twentieth embodiment. Reference numeral 1301 denotes an element identifier for specifying an element in the database. Element identifier (130
1) is composed of an attribute identifier (1301a) and an element number within attribute (1301b).

Reference numeral 1301a denotes an attribute identifier by which the value of the attribute of the element can be obtained by conversion by calculation or the like. When it is desired to represent a plurality of attributes, the attribute identifier (1301a) may be a sequence of a plurality of attribute identifiers. In the present embodiment, the attribute identifier (1301a) is composed of an attribute 1 identifier (1301c) and an attribute 2 identifier (1301d). When the attribute identifier (1301) is used by being divided into a plurality of fields as described above, the method of dividing the attribute is applied to all elements stored in the database in a unified manner. It is assumed that the division method is known. 1301b is the same attribute identifier (1301b) in one database
This is the element number within the attribute that specifies the element having a).

As described above, in the present embodiment, the attribute identifier (1301) is added to the element identifier (1301) for specifying the element.
1a) is stored, and the attribute of the element can be obtained by converting the attribute identifier (1301a). When the element is represented by the element identifier (1301), the correspondence table to the original element or attribute is referred to Attributes can be acquired without doing so, and the practical effect is great.

In this embodiment, the database is a map database, elements are road links, element identifiers (1301) are identifiers of road links, attribute identifiers (1301a) are identifiers of roads, identifiers of attributes 1 and 2, (1301c, 1301d) are the road type and road number, which are the attributes of the road, and the element number within the attribute (1301b)
Is a unique number within the same road, the database used in the fourth embodiment is obtained.

(Embodiment 22) FIG.
5 is an attribute correspondence table and an element identifier of the embodiment of the database described in FIG. The relation between the database, the element, and the element identifier is the same as in the twentieth embodiment. The attribute of the element stored in the database, for each value,
An attribute identifier has been given.

Reference numeral 1401 denotes an attribute correspondence table. The attribute correspondence table (1401) stores a set of all the attribute identifiers of the elements stored in the database with the values of the attributes indicated by the attribute identifiers. 1401a is an attribute identifier stored in the attribute correspondence table (1401). A value other than the attribute identifier of the element stored in the database may be stored. One attribute identifier (1401
a) must not be stored more than once.

1401b and 1401c are the values of attributes 1 and 2 which are the attributes of the element. In the present embodiment, the values of the two types of attributes are stored, but the types of the attributes are determined according to the method by which the application acquires the attributes. All the attributes of the elements necessary for the application to acquire the attributes are as shown in the attribute correspondence table (1401).
Must contain a value. Attribute correspondence table (1
It is not necessary that any of the attributes stored in 401) be the same as those used by the application. Attributes not used by the application may be included. Regarding a plurality of attribute identifiers (1401a), the values of the corresponding attributes may match.

1402 is an element identifier. The element identifier (1402) includes an attribute identifier (1402a) and an element number within attribute (1402b). Reference numeral 1402a denotes an attribute identifier which is an identifier of an attribute value. The attribute identifier (1401) stored in the attribute correspondence table (1401)
Corresponds to a). Reference numeral 1402b denotes an element number within an attribute that specifies an element having the same attribute identifier (1402a) in one database.

As described above, in the present embodiment, the attribute identifier (1402) is added to the element identifier (1402) for specifying the element.
2a) is stored, the value of the attribute identifier (1402a) is searched from the attribute correspondence table (1401), and the corresponding attribute (14
01b and 1401c), it is possible to acquire an attribute that is not stored in the element identifier (1402) without referring to the original element when the element is represented by the element identifier (1402). , Its practical effect is great.

In this embodiment, the database is a map database, the elements are road links, the attribute correspondence table (1401) is a road correspondence table, and the element identifier (140
2) is the identifier of the road link, and the attribute identifier (1401)
a, 1402a) as the road number, the identifiers (1401b, 1401c) of the attributes 1 and 2 as the road alias and road type, and the attribute number within the attribute (1402b) as a unique number within the same road. This is the database used in mode 7.

(Embodiment 23) FIG.
5 is an attribute correspondence table and an element identifier of the embodiment of the database described in FIG. The relation between the database, the element, and the element identifier is the same as in the twentieth embodiment.

The elements stored in the database are classified into two types: those that cannot express attribute values by element identifiers and those that can. The former is referred to as type 1 and the latter as type 2. In both the type 1 and type 2 element identifiers, an attribute identifier is stored in the element identifier to acquire an attribute. The attribute identifiers stored in the type 1 and type element identifiers are independent of each other, and duplicate identifiers may be used. For the element of type 1, the association between the attribute identifier and the attribute value is performed in the attribute correspondence table (1501). For the type 2 element, an attribute is obtained by converting the attribute identifier.

Reference numeral 1501 denotes an attribute correspondence table. The attribute correspondence table (1501) stores a set of an attribute identifier of a type 1 element among the elements stored in the database, with a value of an attribute corresponding to the attribute identifier.

An attribute identifier 1501a is stored in the attribute correspondence table (1501). The attribute identifier of the type 2 element does not need to be stored in the attribute correspondence table (1501). A value other than the attribute identifier of the element stored in the database may be stored. One attribute identifier (15
01a) must not be stored more than once. 1501b, 15
01c is the value of attributes 1 and 2, which are the attributes of the element. Each of the values of the attribute 1 (1401
b), according to the value of attribute 2 (1401c).

Element identifiers include those that refer to the attribute correspondence table (1501) (1502) and those that do not (1503) when acquiring attributes. Type 1 is the former,
Type 2 corresponds to the latter. To distinguish them, element identifiers (1502 for type 1 and 1502 for type 2)
The value obtained by performing a specific process in 3) is used. In order to obtain the value, a specific one bit of the element identifier (1502 or 1503) may be used, or a plurality of bits may be used and each bit pattern represented by the bit pattern may be assigned to either of them. Or
A specific digit or a plurality of digits may be converted into a notation such as a decimal notation and used as a code therefor.

In the present embodiment, the first one of the element identifiers
It shall be distinguished by the value of the bit. The first bit (1502a) of the type 1 element is 1 and the first bit (1503a) of the type 2 element is 0.

Reference numeral 1502 denotes an element identifier of a type 1 element. This is the reading method designation bit (1502a)
, The attribute identifier (1502b), and the element number within the attribute (1
502c).

The attribute identifier (1502b) corresponds to the attribute identifier (1501a) having the same value in the attribute correspondence table (1501). When acquiring attributes, the attribute correspondence table (15
01).

The attribute element number within attribute (1502c) is a number for specifying a type 1 element having the same attribute identifier (1502b) in one database.

Reference numeral 1503 denotes an element identifier of a type 2 element. This is the reading method designation bit (1503a)
, The attribute identifier (1503b), and the element number within the attribute (1
503c). Attribute identifier (1503b)
By converting, the attribute is obtained. When acquiring an attribute, the attribute correspondence table (1501) is not referred to. The attribute element number in attribute (1503c) is a number for specifying a type 2 element having the same attribute identifier (1503b) in one database.

As described above, in this embodiment, the reading method designation bits (1502a, 1503a) and the attribute identifiers (1502b, 1503b) are stored in the element identifiers (1502, 1503) for specifying the element, and the attribute identifier (1502b, 1503b) is stored. The reading method of 1502b, 1503b) is determined by the reading method designation bits (1502a, 1503a), and depending on the value, the attribute correspondence table is referred to based on the attribute identifier (1502b), or the attribute identifier (1503b) is converted. By making it possible to obtain the value of the attribute by
When an element is represented by an element identifier (1502, 1503), an attribute can be obtained without referring to the original element, and the practical effect is large.

In this embodiment, the database is a map database, the elements are road links, the attribute correspondence table (1501) is a road correspondence table, and the element identifier (150
2, 1503) as road link identifiers, reading method designation bits (1502a, 1503a) as bits specifying the reading method, and attribute identifiers (1501a,
502b and 1503b) as road numbers, identifiers of attributes 1 and 2 (1501b and 1501c) as road common names and road types, and element numbers within attributes (1502c and 1503c)
Is a unique number within the same road, the database used in the tenth embodiment is obtained.

(Twenty-fourth Embodiment) FIG.
5 is an attribute correspondence table and an element identifier of the embodiment of the database described in FIG. The relation between the database, the element, and the element identifier is the same as in the twentieth embodiment.

The elements stored in the database are classified into two types: those that cannot express attribute values by element identifiers and those that can. The former is referred to as type 1 and the latter as type 2. In the type 1 element, an attribute identifier is stored in the element identifier in order to acquire the attribute. As for the type 1 element, the association between the attribute identifier and the attribute value is performed in the attribute correspondence table (1601). In the type 2 element, the attribute value is stored in the element identifier in order to acquire the attribute.

Reference numeral 1601 denotes an attribute correspondence table. Attribute correspondence table (1601), attribute identifier (1601a), attribute 1 (1
601b) and Attribute 2 (1601c), respectively, in the attribute correspondence table (150
1), attribute identifier (1501a), attribute 1 (1501a)
b), according to attribute 2 (1501c).

Reference numeral 1602 denotes an element identifier of a type 1 element. The element identifier (1602) is the T1 code (160
2a), an attribute identifier (1602b), and an element number in attribute (1602c).

A T1 code 1602a indicates that the element having this identifier is a type 1 element. This is attribute 3 (1603) in the identifier of the type 2 element.
A field corresponding to a part of the field of a) is used. The value stored here is attribute 3 (1603).
From the domain of a), it is assumed that the value is previously determined not to be used in the attribute 3 (1603a).

Reference numeral 1602b denotes an attribute identifier indicating the value of the attribute of this element. Reference numeral 1602c denotes a number for specifying an element having the same attribute identifier (1602b) in one database.

Reference numeral 1603 denotes an element identifier of a type 2 element. This is attribute 3 (1603a), attribute 4 (1603a)
3b) and an element number within attribute (1603c).

Reference numeral 1603a denotes an attribute 3 indicating the attribute of this element.
It is. The attribute indicated by attribute 3 (1603a) is obtained by converting the value stored therein. It is assumed that the domain of the attribute 3 is predetermined. 160
3b is an attribute 4 indicating the attribute of this element. Attribute 4 (1
The attribute indicated by 603b) is obtained by converting a value stored therein. Reference numeral 1603c denotes a number for specifying an element having the same attribute 3 and 4 (1603a, b) in one database.

Attribute 3 (1603a) and attribute 4 (1603a)
The number of attributes as in 3b) may be one, or three or more. When an application acquires attributes, all or only some of those attributes may be used.

As described above, in this embodiment, the element identifiers (1602, 1603) for specifying an element are divided into two types according to the attribute to be stored therein, and these are stored in the element identifier of the attribute. The attribute identifiers (1602b, 1602b,
603a and 1603b), and by converting the value or referring to the attribute correspondence table (1601), the value of the attribute can be obtained, so that the element is identified by the element identifier (1602, 1603). When expressed, the value of the attribute can be obtained without referring to the original element, and the area for describing the method of storing the attribute identifier can be shared with the attribute identifier, which has a large practical effect.

In this embodiment, the database is a map database, the elements are road links, the attribute correspondence table (1601) is a road correspondence table, and the element identifier (160
2, 1603) as the identifier of the road link, the attribute identifiers (1601a, 1602b) as the road numbers, and the attribute 1
(1601b) is a road common name, and attribute 3 (1603b)
a) is a prefectural code, attribute 4 (1603b) is a route number, and element numbers in attributes (1602c, 1603)
If c) is a unique number within the same road, it becomes the database used in the thirteenth embodiment.

(Embodiment 25) FIG.
5 is an attribute correspondence table and an element identifier of the embodiment of the database described in FIG. The relation between the database, the element, and the element identifier is the same as in the twentieth embodiment.

The elements stored in the database are classified into two types: those that cannot express attribute values by element identifiers and those that can. The former is referred to as type 1 and the latter as type 2.

In the type 1 element, an attribute identifier is stored in the element identifier in order to obtain the attribute. For elements of type 1, association between attribute identifiers and attributes is performed in an attribute correspondence table (1701). Further, in the present embodiment, the attribute identifier is represented by a combination of a plurality of numbers, but it may be a single number.

In the type 2 element, the attribute value is stored in the element identifier in order to acquire the attribute.

Reference numeral 1701 denotes an attribute correspondence table. In the attribute correspondence table (1701), among the elements stored in the database, a set of an attribute identifier of a type 1 element and a value of an attribute corresponding to the set are stored.

Reference numerals 1701a and 1701b denote attribute identifiers 1 and 2, respectively, stored in the attribute correspondence table (1701). It is not necessary to store a set of attribute identifiers of type 2 elements that do not refer to the attribute correspondence table in the attribute correspondence table (1701). A set of values other than the set of attribute identifiers of the elements stored in the database may be stored.
Do not store more than one set of attribute identifiers. 1701
c is the value of attribute 1 which is the attribute of the element. This is in accordance with attribute 1 (1501b) or attribute 2 (1501c) in the twenty-third embodiment.

Reference numeral 1702 denotes an element identifier of a type 1 element. The element identifier (1702) includes a T1 code (1702a) indicating type 1 and an attribute identifier 1 (17
02b), attribute identifier 2 (1702c), and element number in attribute (1702d).

Reference numeral 1702a denotes a T1 code indicating that the element having this identifier is of type 1, that is, an element that uses the attribute correspondence table when acquiring an attribute from the identifier. Here, a field corresponding to a part of the attribute 2 field in the type 2 element identifier is used. Also, the value stored here is a value that is previously determined not to be used in attribute 2 from the domain of attribute 2 of type 2.

1702b is an attribute identifier 1 indicating the attribute of this element. Here, among the fields corresponding to the attribute 2 in the element identifier of type2, the remaining fields used for the code (1702a) indicating type 1 are used. The attribute indicated by the attribute identifier 1 (1702b) is May or may not be obtainable by converting the value stored therein.

Reference numeral 1702c denotes an attribute identifier 2 indicating the attribute of this element. The attribute indicated by the attribute identifier 2 (1702c) may or may not be obtainable by converting the value stored therein.

By combining attribute identifier 1 (1702b) and attribute identifier 2 (1702c), an attribute identifier is obtained. The same value is used for the attribute identifier 1 (1701a) and the attribute identifier 2 (1701b) in the attribute correspondence table (1701).
And the corresponding attribute 1 (1701c) is obtained to obtain the attribute of this element.

1702d is one database,
This is a number for specifying an element having the same attribute identifier (1702b and 1702c).

Reference numeral 1703 denotes an element identifier of a type 2 element. The element identifier (1703) is the attribute 2 (1703)
a), attribute 3 (1703b), and element number within attribute (1
703c).

An attribute 1703a indicates an attribute 2 indicating the attribute of this element.
It is. The attribute indicated by attribute 2 (1703a) is obtained by converting the value stored therein. It is assumed that the domain of the attribute 2 is predetermined.

Reference numeral 1703b denotes an attribute 3 indicating the attribute of this element.
It is. The attribute indicated by attribute 3 (1703b) is obtained by converting the value stored therein.

1703c is one database,
This is a number for specifying an element having the same attributes 3 and 4 (1703a, b).

Attribute 2 (1703a) and attribute 3 (170
The number of attributes as in 3b) may be one, or three or more. When an application acquires attributes, all or only some of those attributes may be used.

As described above, in the present embodiment, the element identifiers (1702, 1703) for specifying the element are divided into two types according to the attribute to be stored therein, and these are stored in the element identifier of the attribute. The element identifier can be identified by a part of the element identifier, and the area including the part used for the identification can be read as an attribute identifier for both types, and it is read at that time according to the result. The attribute identifiers (1702b, 1703a) are acquired using the location and the values are converted or the attribute correspondence table (170
By referring to 1) or not, the value of the attribute can be obtained, and the element is identified by the element identifier (1702,
When expressed in 1703), the value of the attribute can be obtained without referring to the original element, and the area describing the storage method of the attribute identifier can be shared with the attribute identifier. With respect to the attribute described in the local area, it is not necessary to re-read when acquiring the value of the attribute, and the practical effect is large.

In this embodiment, the database is a map database, the elements are road links, the attribute correspondence table (1701) is a road correspondence table, and the element identifier (170
2, 1703) as road link identifiers, attribute identifier 1 (1701a, 1702b) as road type, attribute identifier 2 (1701b, 1702c) as road number, attribute 1 (1701c) as road alias, attribute 2 (170
3a) is a prefecture code, attribute 3 (1703b) is a route number, and element numbers within attributes (1702d and 1702)
If 3c) is a unique number in the road, it becomes the database used in the sixteenth embodiment.

[0191]

As described above, in the first invention, a route calculating means for acquiring a route to be guided and outputting a sequence of identifiers of road links constituting the route, and a mobile body equipped with the route guiding device. Current position detecting means for detecting a position where the position exists, and outputting an identifier of a road link corresponding to the position;
A road name obtaining means for obtaining and outputting the road name of the road to which the road link belongs from the identifier of the road link, a current position obtained by the current position detecting means, and a route obtained by the route calculating means, Among the road links that constitute the route, those that obtain a road name for creating guidance information are selected based on the current position, and the road name is obtained by giving the road link identifier to the road name obtaining means. And
Guidance control means for creating guidance information for guiding a moving body equipped with the route guidance device from the current position, the route, and the road name, and display means for displaying the guidance information created by the guidance control means, The road names obtained from the identifiers of the road links constituting the route can be displayed as information for guidance.

As a result, guidance information can be generated by the road name obtained from the identifier of the road link, and the guidance information can be displayed without newly reading from the map database. Is obtained.

Second, in the route guidance device, when the road name obtaining means obtains the road name from the road link identifier, the road link identifier is converted to generate the road name. A road name of a road to which a road link belongs can be obtained without referring to a database describing a relationship between a road identifier and a road name.

As a result, when the road name acquiring means acquires the road name from the identifier of the road link, there is an advantageous effect that reading of another database becomes unnecessary.

Thirdly, the route guidance device includes a road correspondence table storing means for storing the correspondence between the road identifier and the road attribute, and the road name obtaining means obtains the road identifier from the road link identifier. By referring to the road correspondence table stored in the road correspondence table storage means on the basis thereof, a road attribute can be obtained from the identifier of the road link and a road name can be created based on the attribute. is there.

Thus, when the road name obtaining means obtains the road name from the road link identifier, it is difficult to directly describe the road link identifier, such as the road common name which is a character string unique to the road. Has an advantageous effect that it can also be used.

Fourthly, in the route guidance device, the road name acquiring means determines whether to refer to the road correspondence table when acquiring the road name from the identifier, based on a part of the identifier of the road link. A road name can be generated based on the information.

Thus, when the road name obtaining means obtains the road name from the road link identifier, it is possible to use only the information obtained from the road link identifier, and when it is necessary to refer to the database. The advantageous effect that it can deal with is obtained.

Fifth, in the route guidance device, a part of the identifier of the road link used when the road name acquiring means determines whether to refer to the road correspondence table can be used as an attribute. is there.

Thus, the value for determining the method of obtaining the road name from the identifier of the road link by the road name obtaining means can be used for obtaining the road name, and the data indicating the attribute and the storage method of the attribute are shown. An advantageous effect of sharing data and saving data size can be obtained.

Sixth, in the route guidance device, the road link identifier field read when the road name acquiring means determines whether or not to refer to the road correspondence table expresses two or more types of attributes, and The method for distinguishing those attributes is to be a field with the minimum number of bits to express at the same time.

Thus, when the road name obtaining means determines the road from the identifier of the road link, the attribute can be extracted from the data read at the time of determining the road name obtaining method, thereby increasing the efficiency of using the data read from the map database. This has the advantageous effect of being able to do so.

[Brief description of the drawings]

FIG. 1 is a block diagram according to Embodiments 1 to 6 of the present invention.

FIG. 2 is an example diagram of an output method of an output unit according to Embodiments 1 to 18 of the present invention.

FIG. 3 is a diagram illustrating the relationship between a road network, roads, and road links;

FIG. 4 is a diagram illustrating an example of a map database according to Embodiments 1 to 19 of the present invention;

FIG. 5 is a flowchart according to Embodiments 1 to 18 of the present invention.

FIG. 6 is a diagram illustrating an example of a road link identifier according to the fourth to sixth embodiments of the present invention.

FIG. 7 is a block diagram according to Embodiments 7 to 18 of the present invention.

FIG. 8 is a diagram illustrating an example of a road link identifier and a road correspondence table stored in a road correspondence table storage unit according to the seventh to ninth embodiments of the present invention;

FIG. 9 is a diagram illustrating an example of a road link identifier and a road correspondence table stored in a road correspondence table storage unit according to the tenth to twelfth embodiments of the present invention.

FIG. 10 is a diagram showing an example of road link identifiers and road correspondence tables stored in road correspondence table storage means according to the thirteenth to fifteenth embodiments of the present invention.

FIG. 11 is a diagram illustrating an example of a road link identifier and a road correspondence table stored in a road correspondence table storage unit according to the sixteenth to eighteenth embodiments of the present invention;

FIG. 12 is an example diagram of a database according to Embodiment 20 of the present invention.

FIG. 13 is an example diagram of element identifiers according to the twenty-first embodiment of the present invention;

FIG. 14 is an example of an attribute correspondence table and element identifiers according to the twenty-second embodiment of the present invention.

FIG. 15 is an example diagram of an attribute correspondence table and element identifiers according to Embodiment 23 of the present invention.

FIG. 16 is an example of an attribute correspondence table and element identifiers according to Embodiment 24 of the present invention.

FIG. 17 is an example diagram of an attribute correspondence table and element identifiers according to the twenty-fifth embodiment of the present invention.

FIG. 18 is a block diagram of a road guidance device according to the related art.

[Explanation of symbols]

101 Route calculation means 102 Current position detection means 103 Road name acquisition means 104 Guidance control means 105 Display means 106 Map storage means 401 Map database 402 Road link data 402a Road link identifier 403 Road link identifier 403a Road identifier 403b Same as Unique number within the road 501 Calculate the route to be guided 502 Detect the current position of the moving object 503 Acquire the road name of the road to which it belongs from the identifier of the road link of the route 504 Create the guidance information 505 Display the guidance information 601 Identify the road link 601a Road identifier 601b Unique number within the same road 601c Road type 601d Road number 701 Road correspondence table storage means 801 Road correspondence table 801a Road number 801b Common name 801c Road type 802 Road Link identifier 802a Road number 802b Unique number within the same road 901 Road correspondence table 901a Road number 901b Road common name 901c Road type 902 Road link identifier (when road correspondence table is used) 902a Bit for specifying reading method 902b Road number 902c Unique number within the same road 903 Road link identifier (when not using road correspondence table) 903a Bit specifying reading method 903b Road number 903c Unique number within the same road 1001 Road correspondence table 1001a Road number 1001b Street common name 1001c Road type 1002 Road link identifier (other than prefectural road) 1002a Code indicating other than prefectural road 1002b Road number 1002c Unique number within the same road 1003 Road link identifier (Prefectural road) 1003a Prefectural code 1003b Line number 1003c Unique number within the same road 1101 Road correspondence table 1101a Road type 1101b Road number 1101c Road alias 1102 Road identifier (other than prefectural road) 1102a Code other than prefectural road 1102b Road type Road number 1102d Unique number within the same road 1103 Road link identifier (prefecture road) 1103a Prefectural code 1103b Route number 1103c Number unique within the same road 1201 Database 1202 Element data 1203 Element identifier 1203a Attribute identifier 1203b Element number in attribute 1301 Element identifier 1301a Attribute identifier 1301b Element number in attribute 1301c Attribute 1 1301d Attribute 2 1401 Attribute correspondence 1401a Attribute identifier 1401b Attribute 1 1401c Attribute 2 1402 Element identifier 1402a Attribute identifier 1402b Element number in attribute 1501 Attribute correspondence table 1501a Attribute identifier 1501b Attribute 1 1501c Attribute 2 1502 Element identifier (type 1) 1502a Reading method designation bit 1502b Attribute identifier 1502c Attribute Internal element number 1503 Element identifier (type 2) 1503a Reading method designation bit 1503b Attribute identifier 1503c Attribute element number 1601 Attribute correspondence table 1601a Attribute identifier 1601b Attribute 1 1601c Attribute 2 1602 Element identifier (Type 1) 1602a T1 code 1602b Attribute identifier 1602c Element number in attribute 1603 Element identifier (type 2) 1603a Attribute 3 1603b Attribute 4 16 03c Element number in attribute 1701 Attribute correspondence table 1701a Attribute identifier 1 1701b Attribute identifier 2 1701c Attribute 1 1702 Element identifier (Type 1) 1702a T1 code 1702b Attribute identifier 1 1702c Attribute identifier 2 1702d Element number in attribute 1703 Element identifier (Type 2) 1703a Attribute 2 1703b Attribute 3 1703c Element number in attribute

Claims (25)

[Claims] A route calculating means for acquiring a route to be guided and outputting a sequence of identifiers of road links constituting the route;
A current position detecting means for detecting a position where a moving object equipped with the route guidance device is present and outputting an identifier of a road link corresponding to the position; and a road name of a road to which the road link belongs from the road link identifier. The road name obtaining means for obtaining and outputting, the current position obtained by the current position detecting means, and the route obtained by the route calculating means are inputted, and for generating guidance information among the road links constituting the route. The road name is selected based on the current position, the road name obtaining means is given an identifier of the road link to obtain a road name, and the road name is obtained from the current position, the route, and the road name. It is provided with guidance control means for creating guidance information for guiding a moving object equipped with a route guidance device, and display means for displaying the guidance information created by the guidance control means. To, route guidance system. 2. A first step of acquiring a route to be guided and outputting a sequence of identifiers of road links constituting the route, and determining a position where a moving body equipped with a device implementing the route guidance method exists. The second step of detecting and outputting the identifier of the road link corresponding to the position, the road constituting the path based on a comparison between the path obtained in the first step and the current position obtained in the second step Of the link identifiers,
A third step of selecting a road name that needs to be acquired for creating guidance information, and acquiring and outputting the road name of the road to which the road link belongs from the identifier of the road link selected by the third step; The fourth step and the first
From the route obtained in the step, the current position obtained in the second step, and the road name obtained in the fourth step, to create guidance information for guiding a mobile body equipped with the device implementing the route guidance method. And a sixth step for displaying the guidance information created in the fourth step. 3. A first step of acquiring a route to be guided and outputting a sequence of identifiers of road links constituting the route, and determining a position where a moving body having a device equipped with the route guidance method exists. The second step of detecting and outputting the identifier of the road link corresponding to the position, the road constituting the path based on a comparison between the path obtained in the first step and the current position obtained in the second step Of the link identifiers,
A third step of selecting a road name that needs to be acquired for creating guidance information, and acquiring and outputting the road name of the road to which the road link belongs from the identifier of the road link selected by the third step; The fourth step and the first
From the route obtained in the step, the current position obtained in the second step, and the road name obtained in the fourth step, to create guidance information for guiding a mobile body equipped with the device implementing the route guidance method. Route guidance program storage medium that records a route guidance program realized by a fifth step of performing and a sixth step of displaying the guidance information created in the fourth step in a computer-readable format. . 4. The method according to claim 1, wherein the road name obtaining means converts the road link identifier to generate the road name when obtaining the road name from the road link identifier.
A route guidance device as described. 5. The route guidance according to claim 2, wherein in the fourth step, when the road name is obtained from the road link identifier, the road link identifier is converted to generate the road name. Method. 6. A route guidance program storage medium storing the route guidance program according to claim 5 in a format readable by an electronic computer. 7. A road correspondence table storing means for storing a correspondence between a road identifier and a road attribute, wherein a road name obtaining means obtains a road identifier from a road link identifier, and uses the road correspondence based on the road identifier. 2. The route guidance device according to claim 1, wherein a road name is created based on a road attribute obtained from a road link identifier by referring to a road correspondence table stored in a table storage unit. . 8. In a fourth step, a road identifier is obtained from a road link identifier and a road correspondence table is referred to to obtain a road attribute from the road link identifier. 3. The route guidance method according to claim 2, wherein a road name can be created. 9. A route guidance program storage medium in which the route guidance program according to claim 8 is recorded in a format readable by an electronic computer. 10. The road name obtaining means determines whether to refer to a road correspondence table based on a part of the identifier when obtaining the road name from the identifier of the road link, and generates the road name based on the determination. The route guidance device according to claim 7, wherein: 11. In a fourth step, when a road name is acquired from an identifier of a road link, whether to refer to a road correspondence table is determined by a part of the identifier, and a road name is generated based on the determination. 9. The route guidance method according to claim 8, wherein: 12. The route guidance program according to claim 11,
A route guidance program storage medium recorded in a format readable by an electronic computer. 13. The road name acquiring means uses a part of the identifier of the road link used in determining whether or not to refer to the road correspondence table, also in acquiring the road name. The route guidance device according to claim 10. 14. The method according to claim 4, wherein in the fourth step, a part of the identifier of the road link used in determining whether to refer to the road correspondence table is also used for obtaining the road name. 12. The route guidance method according to item 11. 15. The route guidance program according to claim 14,
A route guidance program storage medium recorded in a format readable by an electronic computer. 16. A method in which a road link identifier field which is read when the road name obtaining means determines whether or not to refer to the road correspondence table expresses two or more types of attributes and distinguishes those attributes. 14. The route guidance device according to claim 13, wherein a field having a minimum number of bits is also used to simultaneously represent the field. 17. A method in which in a fourth step, a road link identifier field to be read when determining whether to refer to a road correspondence table represents two or more types of attributes and distinguishes those attributes. Is also the field of the minimum number of bits to express simultaneously,
The route guidance method according to claim 14. 18. The route guidance program according to claim 17,
A route guidance program storage medium recorded in a format readable by an electronic computer. 19. A computer reads a map database provided with road links, each of which is assigned an identifier, and by performing a predetermined process on the identifier, the attribute of the road to which the road link belongs can be obtained. A map database storage medium recorded in a possible format. 20. A computer readable database, characterized in that an identifier is assigned to each of the elements to be stored, and an attribute relating to the element can be obtained by performing a certain process on the identifier. Database storage media recorded in various formats. 21. The database recording medium according to claim 20, wherein a predetermined process performed when acquiring an attribute related to the element from the identifier of the element is conversion of the identifier. 22. An attribute correspondence table, which is a correspondence table between attribute identifiers and attributes, wherein certain processing performed when acquiring an attribute related to the element from the element identifier is performed by converting the attribute identifier from the element identifier. 21. The database recording medium according to claim 20, wherein the attribute is acquired by acquiring the attribute and referring to the attribute correspondence table based on the acquired attribute. 23. A process for acquiring an attribute related to an element from an element identifier first obtains a value indicating whether or not to refer to an attribute correspondence table from the element identifier.
23. The database recording medium according to claim 22, wherein attributes are acquired based on the attribute. 24. In a certain process performed when acquiring an attribute related to an element from an element identifier, a field in the element identifier indicating whether to refer to the attribute correspondence table can be used for acquiring the attribute. 24. The database recording medium according to claim 23, wherein: 25. A fixed process performed when acquiring an attribute related to an element from an element identifier, when determining whether or not to refer to the attribute correspondence table, the field acquired from the element identifier includes two or more types of fields. 25. The database recording medium according to claim 24, wherein the attribute can be expressed and a method for distinguishing those attributes can be represented by a field having a minimum number of bits to simultaneously express.