JPH11161157A - Map data processing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To delete and acquire map data in an apparatus for acquiring necessary map data from an external information center in order to efficiently utilize the memory capacity for storing the map data. SOLUTION: Map data acquired from an information center via a communication device 14 is stored in a data storage device 18. The map data in the data storage device 18 is divided into types such as route calculation data, terrain data, highway data, and local road data, and the necessity of each data is evaluated based on the distance from the current position. If there is no free space in the data storage device 18, the data types are deleted sequentially from the type having the least necessity, and new map data is acquired from the information center and stored. Instead of deleting and acquiring map data for each area,
Since the data is deleted and acquired for each type, it is possible to leave only the terrain data even in the area where the vehicle has traveled.
Capacity can be used effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a map data processing device, and more particularly to a device for acquiring necessary map data from an information center.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a system in which necessary map data is obtained from an external information center when necessary in consideration of the capacity of a storage device mounted on a moving body such as a vehicle.

For example, Japanese Patent Application Laid-Open No. Hei 7-262493 discloses that a mobile station and a center station communicate map information of the mobile station by mobile communication, and map information corresponding to the level of detail required by the mobile station. A system for distributing the data is disclosed, and it is disclosed that when the acquired map data becomes unnecessary, the map data is appropriately deleted for each area to secure the free space of the storage device.

[0004]

However, if the map data is deleted collectively for each area, all the data in the area will be lost. For example, it is desired to know only the outline of the area again. In this case, there is a problem that the map data of the area must be requested and obtained again from the external information center.

[0005] Even when necessary map data is obtained from an information center, if map data is obtained collectively for each area, if an error occurs during communication, data for that area can be obtained. However, there was a problem that required information could not be obtained quickly.

That is, in general, the operator often wants to know only the outline of the area quickly. However, when a communication error occurs, the operator cannot know even the outline, resulting in a decrease in system utilization efficiency. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and its purpose is to delete only data that is deemed unnecessary and to quickly obtain only truly necessary data. It is an object of the present invention to provide a map data processing device that enables efficient use of a storage device and quick presentation of map data.

[0008]

In order to achieve the above object, a first invention is a storage means for storing map data,
Determining means for determining the necessity of map data stored in the storage means or map data to be stored in the storage means for each type; and map data stored in the storage means based on the need And processing means for deleting map data for each type or storing map data for each type in the storage means. By performing processing (deletion or storage (storage)) for each type of map data, instead of performing collective processing for each area, it is possible to improve the use efficiency of the storage means. The “type” does not mean the scale of the map, but means the attribute of data such as road data, terrain data, and place name data included in the map data.

According to a second aspect of the present invention, in the first aspect, a pattern of a type to be deleted from the storage means or a type to be stored in the storage means is multistage. By setting the pattern in multiple stages, processing according to the capacity of the storage unit can be performed.

In a third aspect based on the second aspect, the processing means selects one of the multi-stage type patterns in accordance with the free space of the storage means.

In a fourth aspect based on the first to third aspects, the type includes at least a route calculation type and a drawing type.

In a fifth aspect based on the first to fourth aspects, the determining means determines the necessity based on a distance between a current position and the map data. It is generally considered that the longer the distance from the current position is, the lower the necessity of the map data is. Therefore, the type of high necessity can be preferentially left or stored in the storage means.

According to a sixth aspect of the present invention, in the first to fourth aspects, the determining means determines the necessity based on an elapsed time since a previous use of the map data. I do. The longer the elapsed time since last use,
In general, it is considered that the necessity of the map data is reduced, so that the type of high necessity can be preferentially left or stored in the storage means.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 is a block diagram showing the configuration of the first embodiment. In the present embodiment, a case where the map data processing device is mounted on a vehicle will be described. GPS (Global Positioning
The system 10 receives a position signal from a GPS satellite (not shown) and detects the position of the vehicle, and outputs the detected position signal to the control device 16.

The sensor 12 includes a vehicle speed sensor, a direction sensor, and the like, and outputs a detection signal to the control device 16. The control device 16 detects the position of the own vehicle with high accuracy based on the position signal from the GPS 10 and the vehicle speed signal and the azimuth signal from the sensor 12.

The communication device 14 includes a communication device for transmitting and receiving data to and from an optical beacon or a radio wave beacon, a car telephone, and the like. The transmitted map data is received and output to the control device 16. Further, it receives an optical beacon, a radio beacon, or traffic information provided by FM multiplex broadcasting, and outputs it to the control device 16.

The control device 16 is constituted by a microcomputer, and stores the map data supplied from the communication device 14 in the data storage device 18 via the data bus. In addition, in order to execute a well-known navigation function, map data is read out from the data storage device 18 as appropriate, and is superimposed and displayed on the output device 20 together with the detected vehicle position. The route is searched, and the obtained guide route is displayed on the map data of the output device 20. Of course, a speaker may be provided as the output device 20 and route guidance may be performed by voice using a voice synthesis circuit.

The data storage device 18 is composed of a rewritable recording medium such as a hard disk, a semiconductor memory, and a DVD-RAM, and stores map data obtained from an information center.

In the above configuration, if the data storage device 18 has a sufficiently large capacity, it is possible to acquire necessary map data from an external information center and sequentially store the map data. In some cases, it is not possible to secure a sufficient capacity from below or from the viewpoint of cost. In such a case, it is necessary to sequentially delete unnecessary map data to secure a free space for storing the next necessary map data.

Therefore, in the present embodiment, the map data that is no longer required is not deleted from the data storage device 18 for each region at once, but the map data stored in the data storage device 18 is used. Is determined for each type, and the map data is deleted for each type based on the determined necessity.

Hereinafter, the map data deleting process performed by the control device 16 will be described in detail.

As described above, in this embodiment,
Map data is processed for each type. This type is specifically as follows.

A: Route calculation data B: Terrain data C: Arterial road data D: Local road data E: Narrow street data F: Place name data G: Facility data H: Others (railroad, administrative boundaries, etc.) : The route calculation data is data for searching for a guide route from the current location to the destination, and is composed of links and nodes weighted by a predetermined weight.
B: Terrain data is data relating to terrain such as the sea, rivers and mountains other than roads. C: Arterial road data is, for example, arterial road data such as National Highway No. 1 or an expressway. D: local road data and E: narrow street data are finer road data than a main road, F: place name data is data indicating place names, and G: facility data is restaurants, shopping centers, gas stations, etc. This is data on various facilities. B to H can be called drawing data with respect to the route calculation data of A.

As described above, the map data is not divided for each area as in the related art, but is divided for each type of A to H and stored in an external information center in advance. The map data in the data storage device 18 is also divided into map data for each type. When deleting map data from the data storage device 18,
This type is deleted as a unit.

When the control device 16 deletes map data for each type, the necessity is first determined for each type of map data. As a criterion for determining the necessity, for example, a distance x from the detected own vehicle position (current position) to the position indicated by the data can be used.

FIG. 2 shows an example of a selection criterion determined based on the distance x from the detected own vehicle position (current position). This selection criterion is a parameter for evaluating necessity. The reference I is 0 ≦ x ≦ x1, and x1 may be, for example, 20 km.
The reference II is in the range of x1 <x ≦ x2, and x2 can be, for example, 40 km. Criterion III is x
The range is 2 <x ≦ x3, where x3 is, for example, 60 km. The reference IV is in a range of x3 <x ≦ x4, and x4 is, for example, 80 km. The reference V is x4 <x. Therefore,
For example, if certain map data is data located 40 km from the current position, the selection criterion for the data is II, and the selection criterion is V for data located 100 km from the current position. The further from the current position, the greater the value of the selection criterion and the lower the need.

FIG. 3 schematically shows a process for determining the deletion level using the selection criteria (necessity level) determined as described above. The deletion level determines which type of the above-described map data is to be deleted. In the present embodiment, five levels of-are prepared, and nine levels 1 to 9 are used as patterns for determining the deletion level. The reason why the deletion level determination pattern is multi-stage is to select an optimum deletion level according to the free space of the data storage device 18, and details thereof will be described later.

In the figure, for example, when the deletion level determination pattern is pattern 1, all of the selection criteria I to V are set to the deletion level. This means that all data is at the deletion level regardless of the distance from the current position.

When the deletion level determination pattern is pattern 2, the selection criteria I to IV are set as the deletion level, and V is set as the deletion level. This means that the data whose distance from the current position is less than x4 (for example, 80 km) has the deletion level, and when the data from the current position is further than that, the deletion level is set.

Similarly, when the deletion level determination pattern is pattern 3, the selection criteria are I to III, the deletion level, IV is the deletion level, and V is the deletion level.

In the case of pattern 4, the selection criteria are I to II
Indicates a deletion level, III indicates a deletion level, IV indicates a deletion level, and V indicates a deletion level.

In the case of pattern 5, the selection criterion I is the deletion level, the selection criterion II is the deletion level, the selection criterion III is the deletion level, the selection criterion IV is the deletion level, and the selection criterion V
Is the deletion level.

In the case of pattern 6, the selection criterion I is a deletion level, the selection criterion II is a deletion level, the selection criterion III is a deletion level, and the selection criteria IV to V are deletion levels.

In the case of pattern 7, the selection criterion I is the deletion level, the selection criterion II is the deletion level, and the selection criteria III to
V is the deletion level.

In the case of pattern 8, the selection criterion I is the deletion level, and the selection criteria II to V are the deletion levels.

In the case of pattern 9, all the selection criteria I
To V are the deletion levels.

FIG. 4 shows the types to be deleted at each of the levels of deletion to. That is, in the case of the deletion level, there is no type to be deleted, and any of the types A to H described above is held in the data storage device 18 as it is.

The deletion levels are E: narrow street data and H:
Others (railroads, administrative boundaries, etc.) are types to be deleted, and other types, such as B: terrain data, are not deleted.

At the deletion level, the type to be deleted is E:
Narrow street data, F: Place name data, G: Facility data, H:
Others, for example, C: highway data are not deleted.

At the deletion level, types to be deleted are D: local road data, E: narrow street data, F: place name data, G: facility data, and H: other.

At the deletion level, the types to be deleted are A: all types except the route calculation data. In other words, all types are not deleted at the deletion level,
,..., The greater the level, the more types are deleted.

Therefore, for example, when the deletion level determination pattern is 5, the selection criterion I is the deletion level, the selection criterion II is the deletion level, the selection criterion III is the deletion level, and the selection criterion IV.
Is the deletion level and the selection criterion V is the deletion level, so that none of the data from the current position to x1 is deleted, and E: narrow street data and H for data far from x1 and within x2 from the current position. : Others are deleted,
For data farther than x2 and within x3 from the current position, E: narrow street data, F: place name data, G: facility data,
H: Others are deleted, x4 farther than x3 from current position
For data within, D: local road data, E: narrow street data, F: place name data, G: facility data, H: others are deleted, and for data beyond x4 from the current position, A: route calculation data All types are deleted except for the above.

As described above, the control device 16 determines the necessity of each data type using the distance from the current position as a determination criterion, and determines whether or not to delete each data type. Hereinafter, a specific deletion process of the control device 16 will be described.

FIG. 5 shows a processing flowchart of the control device 16 functioning as the judgment means and the processing means. First, the control device 16 selects the deletion level determination pattern P from the deletion level determination patterns 1 to 9 shown in FIG.
Is set to 1 (S101). The deletion level determination pattern 1 is a pattern in which there is no type to be deleted and all are left. After setting the deletion level determination pattern P to 1, it is determined whether or not there is free space in the data storage device 18 for newly storing map data (S102). If there is a free space that can be stored in the data storage device 18, the process is terminated as it is not necessary to delete the map data.
On the other hand, if there is no free space in the data storage device 18 for storing the new map data, a deletion level corresponding to the deletion level determination pattern is obtained and each type is deleted (S103). In the case of the pattern 1, there is no change in the capacity of the data storage device 18 because there is no type to be deleted.

Next, only one deletion level determination pattern P is incremented. If the deletion level determination pattern is 1 in the previous processing, the deletion level determination pattern is 2 (S104). Then, the deletion level determination pattern P
Are repeated until the value becomes 9. Specifically, first, the deletion level determination pattern P is set to 2, and it is determined again whether or not there is free space that can be stored in the data storage device 18 (S102). Since none of the types has been deleted in the previous processing, it is determined that there is no free space that can be stored in the data storage device 18 again, and the type is deleted by obtaining the deletion level (S
103). When the deletion level determination pattern P is 2,
The selection criteria I to IV have no deletion level and there is no type to be deleted. Is the type to be deleted. Therefore, in the process of S103, the narrow street data and other data that are at least x4 from the current position stored in the data storage device 18 are deleted. As a result, free space is secured in the data storage device 18.

Next, the deletion level determination pattern P is set to 2 again.
Is increased by 1 to 3, and it is determined again whether or not there is free space in the data storage device 18 to store new map data (S102). If sufficient free space is not yet secured even after deleting some types with the deletion level determination pattern P being 2, the deletion level determination pattern P
Is further increased to 3, the types to be further deleted are increased. That is, when the deletion level determination pattern P is 3, the selection criteria I to III have no type to be deleted, but the selection criterion IV, that is, the data which is far from x3 and within x4 from the current position, has the deletion level E: Street data and H:
Other data is to be deleted, and the selection criterion V, that is, data that is more than x4 from the current position is at the deletion level. E: narrow street data, F: place name data, G: facility data, and H: the type of other data to be deleted. Become. Thereby, since more types are deleted, more free space is secured in the data storage device 18.

The above processing is repeated, and if sufficient free space is secured in the data storage device 18 at any stage of the deletion level determination pattern, the deletion processing ends.
Even if the deletion level determination pattern P becomes 9, a sufficient free space is not secured in the data storage device 18 (S
(YES in 105), finally, A: Deletion of route calculation data is executed (S106).

As described above, the deletion level determination patterns prepared in multiple stages are sequentially selected in accordance with the free space of the data storage device 18, and data of a type that is far from the current position and is less necessary is sequentially deleted. By doing so, the necessary free space in the data storage device 18 is ensured, and the relatively high-necessity data such as the route calculation data of A, the terrain data of B, and the main road data of C have priority. Therefore, the route can be appropriately calculated using these data, and a schematic diagram of the area can be output to the output device 20 quickly. Therefore, even in an area where driving has already been performed and the map data of the area is originally unnecessary, the operator does not need to newly obtain the map data from the information center if the user wants the rough display. The data can be easily read out from the data storage device and displayed.

In the present embodiment, the types of map data are roughly classified into A: route calculation data and B-H drawing data, but the present invention is not limited to this. It is possible to divide the map data for each type.

In the present embodiment, the selection criterion is determined based on the detected distance from the own vehicle position (current position). However, the selection criterion may be determined based on the elapsed time since the last use. It is possible. Specifically, assuming that the elapsed time since the last use is y, 0 ≦ y ≦ y1 (y
1 is one week, for example), the selection criterion I, y1 <y ≦ y
In the case of 2 (y2 is, for example, 2 weeks), the selection criterion is II, and so on. As a result, the longer the elapsed time from the previous use, that is, the older the type of data, the higher the priority of deletion from the data storage device 18. Note that the time unit may be changed at an exponential function instead of at regular intervals.

It is also possible to determine the selection criterion by using, as an index, the number of uses within a certain time, instead of the distance from the current position or the elapsed time since the last use.

In this embodiment, the deletion level pattern is set to 1 first, and the pattern is sequentially changed to 2, 3,... While checking the free space of the data storage device 18. It is also possible to set the deletion level pattern to 5 from the beginning based on the 18 free capacities.

Further, it is also possible to change the index of the selection criterion in accordance with the type of map data. For example, A: for route calculation data, the distance from the current position is used as an index; With regard to, the number of times of use can be used as an index of selection criteria. In this case, the route calculation data is sequentially deleted according to the distance from the current position, and the drawing data is sequentially deleted according to the number of uses. In general, route calculation data is necessary for a detailed search around the current position, and the closer the map data, the higher the need. Further, the drawing data is frequently used around the destination and the guidance route regardless of the distance from the current position. Therefore, by changing the index of the selection criterion according to the type of the map data, the efficiency of the data storage device 18 can be more efficiently increased.

<Second Embodiment> In the above-described first embodiment, the case where the map data stored in the data storage device 18 is deleted for each type has been described. The case where the map data obtained from the above is stored in the data storage device 18 for each type will be described. The basic configuration is the same as the configuration shown in FIG.

FIG. 6 shows the relationship between the selection criteria and the determination range in this embodiment. Similar to FIG. 2, the selection criterion is determined based on the distance x from the current position. Specifically, when 0 ≦ x ≦ x1 (x1 is 20 km, for example), the selection criterion is set to I, and x1 <x ≦ In the case of x2, the selection criterion is II.

FIG. 7 shows the relationship between the acquisition level and the acquisition level determination pattern, and corresponds to FIG. 3 in the first embodiment. The acquisition level determination patterns are prepared from pattern 1 to pattern 9, and the acquisition level is prepared. For example, in the acquisition level determination pattern 1, the selection criteria I to V are acquisition levels,
In the acquisition level determination pattern 2, the selection criteria I to IV are the acquisition level, and the selection reference V is the acquisition level.

FIG. 8 shows the acquisition levels shown in FIG.
At the acquisition level, B: terrain data, C: arterial road data, D: regional road data, E: narrow street, as the types to be acquired from the information center and stored in the data storage device 18 Data, F: place name data,
G: Facility data, H: Other (railroad, administrative world, etc.). That is, at this acquisition level, all types of map data except for A: route calculation data are stored in the data storage device 18. At the acquisition level, B: terrain data, C: arterial road data,
D: Local road data, F: Place name data, G: Facility data are set. At the acquisition level, only B: terrain data, C: arterial road data, and D: local road data are set as acquisition types. For example, place name data and the like are not acquired from the information center and are not stored in the data storage device 18. At the acquisition level, B: terrain data and C: arterial road data are types to be acquired, and these are stored in the data storage device 18. At the acquisition level, there is no acquisition type, and all types of map data are not acquired from the information center and are not stored in the data storage device 18.

Therefore, for example, when the acquisition level determination pattern is, the data within x1 from the current position is A
All types of data except the route calculation data are obtained and stored in the data storage device 18. For data farther than x1 and within x2 from the current position, B: terrain data, C:
Main road data, D: local road data, F: place name data, G: facility data are acquired and stored, and x from the current position
B: Topographic data, C: Highway data, and D: Local road data are acquired and stored for data farther than x2 and within x3, and B: topographic data and C for data farther than x3 and within x4 of the current position. : The main road data is acquired and stored, and data farther than x4 from the current position is not acquired without acquiring any type.

As described above, the control device 16 determines the necessity of each data type using the distance from the current position as a determination criterion, and determines whether to store the data in the data storage device 18 for each data type. decide. Hereinafter, a specific acquisition process of the control device 16 will be described.

FIG. 9 shows a flowchart of the acquisition process of the control device 16 functioning as the determining means and the processing means. First, the acquisition level determination pattern P is initialized to 9 (S201). Then, it is determined whether there is no free space that can be stored in the data storage device 18 (S202).
If there is no free space that can be stored in the data storage device, the acquisition process is not performed because it cannot be stored even if acquired.
First, the deletion processing shown in the first embodiment is executed. on the other hand,
If there is free space in the data storage device 18, an acquisition level corresponding to the acquisition level determination pattern 9 is obtained, and each type is stored (S203). Specifically, as described above, in the acquisition level determination pattern 9, all of the selection criteria I to V are set to the acquisition level, and there is no type to be acquired (see FIG. 8). Therefore, at this stage, necessary information cannot be obtained from the information center, and the data storage device 1
8 will not be stored.

Next, the acquisition level determination pattern P is decreased by one, and the acquisition level determination pattern P is set to 8 (S20).
4). Then, the processing of S202 to S204 described above is repeated until the acquisition level determination pattern P becomes 1 (S2
05). Specifically, after the acquisition level determination pattern P is set from 9 to 8, it is determined again whether there is free space that can be stored in the data storage device 18 (S202). In the previous process, no map data was acquired from the information center, and no map data was stored in the data storage device 18. Therefore, it was determined that there was still free space available in the data storage device 18, and the acquisition level determination pattern 8 Then, the type is obtained and stored in the data storage device 18 (S203). In the acquisition level determination pattern 8, the selection criterion I is the acquisition level, and the selection criteria II to V
Is an acquisition level. For data within x1 from the current position, B: terrain data and C: arterial road data are acquired from the information center and stored in the data storage device 18, and for data farther than x2 from the current position, Do not get.

Then, the acquisition level determination pattern is further reduced by one from 8 and set to 7 (S204), and if there is still free space to be stored in the data storage device 18, the acquisition level determination pattern 7 is used. An acquisition level is obtained and each type is stored (S203). In the acquisition level determination pattern 7, since the selection criterion I is the acquisition level, the selection criterion II is the acquisition level, and the selection criteria III to V are the acquisition levels, the data within x1 from the current position are B: terrain data, C: main road. Data: D: Local road data is obtained from the information center, and B: terrain data and C:
The main road data is acquired from the information center and stored in the data storage device 18.

As described above, the information is sequentially requested and obtained from the information center in descending order of necessity.
In the case where an error occurs during communication, for example, topographical data and highway data are obtained with priority, so that a schematic diagram or the like can be output to the output device 20 quickly.

In this embodiment, the acquisition level determination pattern can be set to 5 from the beginning without sequentially changing the acquisition level determination pattern from 9 in accordance with the free space of the data storage device 18.

[0066]

As described above, according to the present invention, since map data is deleted or acquired for each type having a high necessity, the required map capacity can be efficiently utilized by efficiently using the limited storage capacity of the storage device. Data can be provided quickly.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram for determining a selection criterion in the first embodiment.

FIG. 3 is an explanatory diagram showing a relationship between a deletion level and a deletion level determination pattern in the first embodiment.

FIG. 4 is an explanatory diagram of a deletion level in the first embodiment.

FIG. 5 is a flowchart of a deletion process of the control device according to the first embodiment.

FIG. 6 is an explanatory diagram for determining a selection criterion in a second embodiment.

FIG. 7 is an explanatory diagram showing a relationship between an acquisition level and an acquisition level determination pattern in the second embodiment.

FIG. 8 is an explanatory diagram of an acquisition level in the second embodiment.

FIG. 9 is a flowchart of an acquisition process of a control device according to the second embodiment.

[Explanation of symbols]

10 GPS, 12 sensors, 14 communication devices, 16
Control device, 18 data storage device, 20 output device, 2
2 Operating device.

Claims (6)

[Claims] A storage unit for storing map data; a determination unit for determining the necessity of map data stored in the storage unit or map data to be stored in the storage unit for each type; Processing means for deleting the map data stored in the storage means for each type based on characteristics, or for storing the map data in the storage means for each type. 2. The map data processing apparatus according to claim 1, wherein patterns of types to be deleted from said storage means or types to be stored in said storage means are multistage. 3. The map data processing apparatus according to claim 2, wherein the processing means selects one of the multi-stage type patterns according to a free space of the storage means. 4. The map data processing device according to claim 1, wherein the type includes at least a route calculation type and a drawing type. 5. The map data processing apparatus according to claim 1, wherein said determination means determines said necessity based on a distance between a current position and said map data. 6. The map data processing according to claim 1, wherein the determination unit determines the necessity based on an elapsed time since a previous use of the map data. apparatus.