JP2004125500A - Navigation system for motor vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation system for a motor vehicle, capable of efficiently storing data by selectively compressing data stored in a storage device, according to the use frequency and degree of requests of a user and increasing the space area in the storage device. <P>SOLUTION: A data sequencing part 8, a compression processing part 9, and a data storage part 10 are incorporated in the navigation system 1. The data sequencing part 8 is a means of sequencing data according to both a past access frequency in the data storable in a hard disk 7 and the compared distance between the location of one's own vehicle and a predetermined coordinate location. The compression processing part 9 processes the compression of selected data and processes the compression of both low-frequency data, to which few accesses have been made and long-distance data having a long distance between the location of one's own vehicle and the coordinate location. The data storage part 10 is a means for storing the data compressed by the compression processing part 9 in the hard disk 7. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicular navigation device for reading map data stored in a large-capacity storage means such as a hard disk, displaying an image, and guiding a route to a destination, and in particular, improving data compression and storage technology. The present invention relates to a vehicular navigation device provided.
[0002]
[Prior art]
2. Description of the Related Art In recent years, vehicular navigation devices have been in high demand, and various research and development have been made. Recently, a rewritable large-capacity external storage device such as a hard disk has become inexpensive, and is used for a navigation device to increase a data storage area. According to such a navigation device, it is possible to store a large amount of various user data such as registration points, voices (MP3, WMA), and images (JPEG).
[0003]
At present, progress in vehicle navigation systems is remarkable, and there is a constant demand for larger storage devices. In order to cope with the increase in the capacity of the storage device, it is necessary to replace the storage device with a large capacity storage device or to add a storage device. However, when replacing the storage device, the stored data must be transferred from the storage device in use to the new storage device, which is troublesome. Moreover, when transferring data, there is a possibility that the data will be lost due to the occurrence of an error. In addition, in the case of a device for a vehicle, since there is a large restriction on the installation space, it is often difficult to increase the number of storage devices in terms of space. Further, whether the device is replaced or added, the purchase cost of the storage device remains unchanged, which imposes an economic burden.
[0004]
Therefore, conventionally, a vehicular navigation device that stores a part of the digitized data in a compressed state in a storage device has been proposed. For example, both compressed data and uncompressed data are stored in a storage device, and it is determined whether the data read from the storage device is compressed data or uncompressed data. It is known that the data is input to the apparatus main body after performing (expansion) processing, and is directly input to the apparatus main body if it is uncompressed data (see Patent Document 1). Also, in this navigation device, data is divided into a plurality of blocks and then compressed, upper data is compressed as lower data index only lower data, or data is compressed based on a possible data range. Various data compression techniques are employed. As another conventional example, a navigation device that partially decompresses compressed data and reads out the decompressed data when a read error of uncompressed data occurs has been proposed (see Patent Document 2). ). According to this device, an unreadable state can be avoided, so that an image can be displayed reliably.
[0005]
[Patent Document 1]
JP-A-8-320648 [Patent Document 2]
JP 10-301488 A
[Problems to be solved by the invention]
The amount of data stored in the storage device is steadily increasing, and there is a limit to increasing the capacity of the storage device. Therefore, there is a need for a vehicular navigation device in which the free space is increased without changing the current storage device.
[0007]
The present invention has been proposed in order to solve such a problem, and its purpose is to selectively compress data stored in a storage device according to a user's use frequency and request level, An object of the present invention is to provide a vehicular navigation device capable of efficiently storing data by increasing a free area of a storage device.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a rewritable large-capacity storage unit that stores digitized data such as map data and route calculation data, and reads data stored in the large-capacity storage unit and reads the data based on the data. The following technical features are provided in a vehicular navigation apparatus including: a position / route detection unit that detects a position of a vehicle and a route to a destination; a display unit that displays a map and an operation menu; and an operation unit. have.
[0009]
The invention according to claim 1 is a data reordering means for arranging data according to a past access frequency in the data storable in the large-capacity storage means; A low-frequency data compression processing means for performing data compression processing in the order of least data, and a data storage means for storing compressed data in the large-capacity storage means.
According to the first aspect of the present invention, the data rearranging unit rearranges the data according to the past access frequency, and the low-frequency data compression processing unit performs the data compression process in the order of the low past access frequency. As a result, it is possible to always selectively compress only data that is infrequently used by the user. Therefore, it is possible to efficiently store data by increasing the free space of the storage device, which can contribute to increasing the capacity of the storage device. Also, since frequently used data is not compressed, decompression processing is not required, and quick and smooth display processing is possible. Therefore, a high-performance, high-quality vehicle navigation device can be provided.
[0010]
According to a second aspect of the present invention, there is provided a data rearranging means for comparing a current position of a vehicle with a predetermined coordinate position in data storable in the mass storage means and arranging data in accordance with a distance between the two. A long-distance data compression processing means for performing compression processing on data in order of increasing distance from the coordinate position to the current position of the vehicle in the data which can be stored in the large-capacity storage means; Compression data storage means for storing in the capacity storage means.
According to the second aspect of the present invention, the data rearranging unit compares the current position of the vehicle with a predetermined coordinate position and rearranges the data according to the distance between the two. Data compression processing is performed in order of increasing distance from the coordinate position to the current position of the vehicle. That is, data near the current position of the vehicle is uncompressed data. Therefore, decompression processing is not required for data expected to have a high user demand, and the data can be displayed quickly and smoothly.
[0011]
According to a third aspect of the present invention, in the vehicular navigation apparatus according to the first or second aspect, the compressed data obtained by performing a compression process on the data that can be stored in the large-capacity storage unit or the non-compressed data that is not subjected to the compression process. Data determining means for determining whether the data is data; low-frequency data having the access frequency lower than a predetermined value; and long-distance data having a distance from the coordinate position to the vehicle position equal to or more than a predetermined value. A compression message output unit that outputs a message indicating that the compression processing is completed when all of the data are determined to be compressed data.
According to the third aspect of the present invention, when the data determination unit determines that at least one of the low-frequency data and the long-distance data is all compressed data, the compressed message output unit determines that the compression processing is completed. Since the message is output, there is no need to worry about repeated compression processing. Further, when the free space of the storage means is insufficient, the compression processing can be further advanced by changing a predetermined value which is a reference when performing the compression processing, and an excellent usability can be obtained. Can be.
[0012]
According to a fourth aspect of the present invention, in the vehicle navigation device according to any one of the first to third aspects, the access frequency, the distance from the vehicle position to the coordinate position, and the determination result of the data determination unit are included. Is settable as a condition for performing data compression processing.
According to the fourth aspect of the present invention, at least one of the access frequency, the distance from the vehicle position to the coordinate position, and the determination result of the data determination unit can be set as conditions for performing data compression processing. Thus, the priority of the data to be compressed can be changed. Thereby, the data storage efficiency can be improved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
(1) Representative Embodiment [Configuration]
Hereinafter, a typical example of the embodiment of the present invention will be specifically described with reference to FIGS. FIG. 1 is a block diagram of the present embodiment, FIG. 2 is a data configuration example in a large-capacity storage unit in the present embodiment, and FIG. Is a conceptual diagram of a compression management file according to the present embodiment, FIG. 4 is a pie chart showing how data is compressed according to the present embodiment, and FIGS. 5 to 8 are flowcharts of operations according to the present embodiment. .
[0014]
As shown in FIG. 1, a hard disk 7 is incorporated in the navigation device 1 as a large-capacity storage means, and a GPS antenna 2, a vehicle speed pulse detection device 3, a display device 4, an audio output device 5, and an operation unit 6 are connected. ing. The hard disk 7 stores digitized data such as map data and route calculation data. The navigation device 1 calculates the position of the own vehicle from the GPS antenna 2 and the vehicle speed pulse detection device 3, reads map data in the vicinity thereof from the hard disk 7, and draws the map data on the display device 4. In addition, when the route is calculated and guided by voice, the voice output device 5 outputs the guidance voice. The operation unit 6 performs operations such as destination setting. The operation unit 6 may be composed of a switch group or a remote controller mounted on the front of the navigation device 1, a touch panel device including the display device 4, or a voice input device.
[0015]
The features of this embodiment are as follows. That is, the navigation device 1 incorporates a data rearrangement unit 8, a compression processing unit 9, a data storage unit 10, and a data determination unit 11. The data rearranging section 8 compares the data stored in the hard disk 7 in the order of access frequency in the past and the position of the vehicle with a predetermined coordinate position, and rearranges the data according to the distance between the two. is there. As a method of arranging, efficiency is improved if data with a high access frequency or data in an area close to the position of the vehicle is arranged on the inner periphery of the disk having a high access speed, and data other than that is arranged on the outer periphery of the disk. As for the coordinate position, for example, a place where the prefectural office exists is set as the coordinate position.
[0016]
The compression processing section 9 performs compression processing of the selected data. More specifically, compression processing is performed on low-frequency data with a low access frequency and long-distance data with a large distance between the vehicle position and the coordinate position. The data storage unit 10 is means for storing the data compressed by the compression processing unit 9 on the hard disk 7.
[0017]
The data determination unit 11 determines whether data that can be stored in the hard disk 7 is compressed data that has been subjected to compression processing or uncompressed data that has not been subjected to compression processing. In the present embodiment, at least one of the access frequency, the distance from the vehicle position to the coordinate position, and the determination result of the data determination unit 11 is set as a condition for performing data compression processing. It is possible. The priority of each setting condition can be changed as appropriate, but it is necessary to clarify it in the specification.
[0018]
FIG. 2 shows an example of a data configuration in the hard disk 7. For example, if the data is divided by prefecture, the map data and search data used for navigation are divided as shown in the figure. In the hard disk 7, a compression management file for managing the compression processing of the stored data is provided.
[0019]
FIG. 3 shows a conceptual diagram of the compression management file. The contents of the compression management file are composed of data divisions, a coordinate position serving as a key at the time of compression, the number of accesses, and a flag indicating whether or not compression has been performed. As described above, the coordinate position is based on the coordinates of the place where the prefectural government is located. When the user uses each data in the hard disk 7, that is, accesses each data, the access frequency is managed by incrementing the access number of the data. When the data is compressed in the flow described later, the compression flag is set to “1”.
[0020]
Here, FIG. 5 shows a flow when the user saves the data. First, the capacity of the data to be stored is acquired (flow 501), and if the free space of the hard disk 7 is larger than the capacity of the data to be stored (flow 502), the data is stored in the hard disk 7 (flow 503). If the free space of the hard disk 7 is smaller than the data capacity to be stored in the flow 502, the flow goes to the flow 504 to perform the compression processing.
[0021]
The compression process is performed as shown in FIG. First, the capacity of data to be saved and the free capacity of the hard disk 7 are checked in the flow 601. Then, the compression management file is searched. At this time, the data rearranging unit 8 rearranges the data that can be stored in the hard disk 7 as described above. Then, candidates are extracted under the following condition items (flow 602).
(1) The order in which the access frequency is low. (2) The position of the distant data by comparing the own vehicle position with the coordinate position of each data in the access management file. However, even if the compressed data is compressed again, there is not much free space. Since there is no increase, and the time required for decompression described later increases, compressed data is excluded from candidates.
[0022]
When searching for a candidate under the above conditions, it is determined whether there is data that can be compressed (flows 901 to 903). First, it is determined whether or not there is data equal to or less than a predetermined value regarding the access frequency (flow 901). If there is no data less than the predetermined value, an error message is returned (flow 606), and this processing ends. On the other hand, if there is data that can be compressed, that is, data that is equal to or less than the predetermined value, the flow proceeds to flow 902.
[0023]
In the flow 902, it is determined whether or not the current distance from the vehicle position to the coordinate position is larger than a predetermined value. If there is no data exceeding the predetermined value, the flow proceeds to the flow 606. If there is data exceeding the predetermined value, the flow proceeds to the flow 903. Move on. In the flow 903, the data determination unit 11 determines whether or not the data has been compressed. If the data has been compressed, the flow proceeds to the flow 606, and if not, the flow proceeds to the flow 604. In the flow 604, the data is compressed by the compression processing unit 9, and a flag in the management file is set.
[0024]
For example, FIG. 4 shows an example in which, when the frequency of use of data in the Kyushu region is equal to or less than a predetermined value, the data in this portion is compressed. Here, since the data amount in the Kyushu region is reduced to about 1/6, the free area is increased by that amount. As for a specific data compression method, various compression algorithms are disclosed, and an appropriate method may be adopted. However, since it is possible to decompress and use the compressed data on another occasion, the compression algorithm must use a lossless compression method. Further, the compressed data requires a data capacity before compression, that is, a data capacity at the time of decompression, so that it is necessary to record it.
[0025]
If the data is compressed, the data at the compression source becomes unnecessary, and is deleted (flow 605). In this way, the process returns to the flow 601 to check the free space. This process is repeated until a sufficient free space is secured. When the free space is secured, the process is terminated and the process returns to the flow 503.
[0026]
When you need compressed data, decompress the data. FIG. 7 shows the flow at that time. Since the decompressed capacity is recorded in the compressed data, the capacity is obtained first (flow 701). If the free space of the hard disk 7 is larger than the capacity of the data to be decompressed (flow 702), the data is decompressed to the hard disk 7 and the compression flag is set to "0". Also, the data before decompression becomes unnecessary and is deleted (flow 703). If the free space of the hard disk 7 is not small in the flow 702, the flow goes to the flow 704 to perform the compression process, and repeats this process until a sufficient free space can be secured. , The compression flag is set to “0”.
[0027]
FIG. 8 shows details of the compression processing in this case. First, in a flow 801, the capacity of the data to be decompressed and the free capacity of the hard disk 7 are checked. Then, data candidates to be compressed are extracted by the method described above (flow 802). It is determined whether there is data that can be compressed (flow 803), and if there is no data that can be compressed, an error message is returned (flow 806), and this processing ends. If there is data that can be compressed, the data is compressed (flow 804), and the compression source data is deleted (flow 805). As in the flow of FIG. 6, free space of the hard disk 7 is secured, and the process returns to the flow 703. As described above, the user can repeatedly use the hard disk 7 by repeatedly compressing and decompressing data.
[0028]
[Effects]
According to the above-described embodiment, the data rearranging unit 8 rearranges data according to the access frequency and the distance from the vehicle position to the coordinate position, and the data compression processing unit determines the frequency of use and the degree of request of the user. Data can be selectively compressed accordingly. Therefore, data can be efficiently stored by increasing the free space of the hard disk 7. In addition, for data that is frequently used and data that is close to the current position, that is, data that is expected to be highly requested by the user, decompression processing is not performed because compression processing is not performed, and quick and smooth display is performed. Processing is possible. Further, at least one of the access frequency, the distance from the vehicle position to the coordinate position, and the determination result of the data determination unit 12 can be set as conditions for performing data compression processing, so that data to be compressed can be set. Priority can be changed. Thereby, the data storage efficiency can be improved.
[0029]
(2) Other Embodiments The present invention is not limited to the above-described embodiment. For example, an embodiment having a compressed message output unit 12 as an embodiment corresponding to claim 3 is described. Included (see FIG. 9). When the data determination unit 11 determines that at least one of the low-frequency data and the long-distance data is all compressed data, the compressed message output unit 12 outputs a message indicating that the compression processing is completed to the display device 4 and the voice. The output is output to the output device 5.
[0030]
In the above embodiment, if there is no data that can be compressed, an error message is returned (flow 606), but in the embodiment of FIG. 9, a message indicating that the compression processing is completed is output to the display device 4 and the audio output device 5. I do. Therefore, the compression processing is not repeated needlessly. If there is not enough free space on the hard disk, the compression processing can be further advanced by changing a predetermined value serving as a reference for the compression processing. Therefore, excellent usability can be obtained, and high quality can be realized.
[0031]
Here, as a unit of data to be compressed, “prefecture” is used as a key. However, if it is map data, a unit called “mesh” obtained by dividing latitude and longitude into a rectangular area based on a predetermined reference may be used, or search data may be used. In such a case, the "station number" of the telephone number of each facility data or the "initial" unit of the name can be considered. In any case, a unit that seems to be optimal may be adopted. Further, not only the data stored in the hard disk 7 but also the data stored by the user himself may be used as a compression candidate, or the user may set the priority of the data to be compressed in advance and compress the data. And may be compressed accordingly. Furthermore, as the compression and decompression are repeated, the data fragmentation progresses. Therefore, when the compression / decompression processing exceeds a predetermined number of times, the fragmentation is automatically eliminated (defragmented), and the data is fragmented. It is desirable to maintain continuity. Further, the condition for performing the data compression process may be any one of the above (1) and (2) or a combination of a plurality of them.
[0032]
【The invention's effect】
As described above, according to the present invention, by providing the data rearranging unit and the data compressing unit, the data stored in the storage device can be selectively compressed according to the frequency of use and the request level of the user. Therefore, it is possible to provide a vehicle navigation device capable of efficiently storing data by increasing the free space of the storage device.
[Brief description of the drawings]
FIG. 1 is a block diagram of a typical embodiment of the present invention.
FIG. 2 is a data configuration example in a large-capacity storage unit.
FIG. 3 is a conceptual diagram of a compression management file according to the embodiment.
FIG. 4 is a pie chart showing how data is compressed according to the embodiment.
FIG. 5 is a flowchart of an operation according to the embodiment.
FIG. 6 is a flowchart of an operation according to the embodiment.
FIG. 7 is a flowchart of an operation according to the embodiment.
FIG. 8 is a flowchart of an operation according to the embodiment.
FIG. 9 is a block diagram of another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Navigation device 2 ... GPS antenna 3 ... Vehicle speed pulse detection device 4 ... Display device 5 ... Sound output device 6 ... Operation unit 7 ... Hard disk 8 ... Data rearrangement unit 9 ... Compression processing unit 10 ... Data storage unit 11 ... Data judgment Part 12: Compressed message output part

Claims (4)

Rewritable large-capacity storage means for storing digitized data such as map data and route calculation data, and reading data stored in the large-capacity storage means to detect a position of a vehicle and a route to a destination based on the data. Position and route detection means, a display unit for displaying a map or an operation menu, and a navigation device for a vehicle including an operation unit.
Data rearranging means for arranging data according to past access frequency in data storable in the mass storage means;
Low-frequency data compression processing means for performing data compression processing in the order of the least frequent access in the data storable in the large-capacity storage means;
And a data storage means for storing the compressed data in the large-capacity storage means. Rewritable large-capacity storage means for storing digitized data such as map data and route calculation data, and reading data stored in the large-capacity storage means to detect a position of a vehicle and a route to a destination based on the data. Position and route detection means, a display unit for displaying a map or an operation menu, and a navigation device for a vehicle including an operation unit.
Among the data that can be stored in the large-capacity storage means, a data rearrangement means for comparing the current position of the vehicle with a predetermined coordinate position and arranging data according to a distance between the two.
A long-distance data compression processing unit that performs data compression processing in the order of the distance in the data that can be stored in the large-capacity storage unit;
A vehicular navigation device comprising: a compressed data storage unit that stores compressed data in the large-capacity storage unit. Data determining means for determining whether compressed data has been subjected to compression processing on data storable in the large-capacity storage means or uncompressed data not subjected to compression processing;
The compression processing is completed when at least one of the low-frequency data with a low access frequency and the long-distance data with a large distance from the coordinate position to the vehicle position is compressed data by the data determination unit. 3. The vehicular navigation device according to claim 1, further comprising a compressed message output unit that outputs a message to the effect. At least one of the access frequency, the distance from the vehicle position to the coordinate position, and the determination result of the data determination means can be set as conditions for performing data compression processing. Item 4. The vehicle navigation device according to any one of items 1 to 3.

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