JP2007041101A - Time series management of map data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To expand a range capable of applying a new object in map data capable of updating data on an object by each object. <P>SOLUTION: An effective period indicating a period in which the actual geography is expressed by the object is given to each object composing the map data. The object is updated by adding a new object OD2 while an old object OD1 remains. In this case, the effective periods added to the new and old objects respectively are allowed to be overlapped. When the objects overlapping the effective periods exists, in displaying a map, the object OD2 issued or investigated most recently is used. In addition, map display using the old object OD1 is enabled in response to designation or the like of a user. Thus, when an error of the object is found, the new object can be applied back to issuance while the old object remains. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for managing and utilizing a map database in a case where the map database includes time information indicating when the geography fits in the geography.

  Map data is used for various purposes such as displaying maps and managing statistical information related to geography. Since the topography and feature conditions change from year to year, it is desirable to update the map data sequentially. Map data can be updated by replacing the entire old data with the newly issued new data every time the latest version is issued at a certain time, such as every fiscal year, or by acquiring only changes from the old data via the network, etc. However, it is performed by a method of incorporating in old data.

  In order to display a map reflecting the current geographical state, it is necessary to update the map data, but depending on the application, it may be necessary to refer to a map at a certain point in the past. As such a situation, for example, when examining statistical data, it is necessary to grasp the transition of the development status of a region such as the construction status of roads and features. In order to respond to such demands, a technique has been proposed in which time information indicating when the geography fits in a map database is added (see Patent Documents 1 and 2).

  For example, Patent Document 1 discloses a technique that enables a map corresponding to a time designated by a user to be displayed by attaching data such as generation time and disappearance time to each object representing a feature. Yes. Patent Document 2 further allows various events related to geography, such as the occurrence of traffic accidents, to be included in attribute data in map data, and by adding time information to this, statistical information at a specific time can be recorded. Techniques that enable analysis and analysis of changes in statistical information over time are disclosed.

Japanese Patent Laid-Open No. 11-312233 JP 2003-330360 A

  The change included when the map data is updated is not only the change in the terrain and the construction status of the features. For example, as a result of redoing the survey, there may be a case where the data of the topography and the feature shape can be acquired with higher accuracy than the conventional map data, and the map data needs to be corrected. This is not a reflection of actual changes in the terrain or the like, but a correction accompanying an improvement in the accuracy of the map data. From the viewpoint of providing a highly accurate map, it is preferable to reflect such correction retroactively not only after the update but also to a past time.

  On the other hand, as explained earlier, since maps are also used for analysis of various statistical information, etc., if the map data at the past time point is modified indefinitely, the results of previous analysis There is also a risk that consistency may be lost. For example, based on previous map data, when it was analyzed that narrow road width was one factor in the occurrence of traffic accidents, past map data If the width of the road is widened indefinitely, a situation may arise in which it is completely unknown how the above-described analysis was performed.

  Conventionally, a method for reflecting a new change in terrain or the like on map data has been studied, but the above-described correction handling has not been sufficiently studied. In view of these problems, an object of the present invention is to provide a technique that enables map data to be managed in a time series including the above-described corrections and effectively used.

  The present invention is directed to a map database that stores map data composed of a plurality of objects. In particular, it is preferable that data can be updated for each object. The map database of the present invention has object management information for specifying each object. In addition, objects associated with object management information and stored at a plurality of periods with different issuance periods or survey periods are stored. Each of these objects is associated with time information that individually indicates when the object fits the geography of the time. Further, this time information is allowed to be duplicated among objects of a plurality of times.

  The time information is information representing a time span including a point in time when a field survey for creating map data is performed. Time information can include points in the past rather than field surveys. When data having a content different from that of a conventional map database has time information including a past time point, this data often corresponds to correction of topographical or feature data from the past.

  By allowing duplication of time information, it is possible to appropriately reflect such corrections in the map database without deleting previous objects. Temporarily, in a map database in which duplication of time information is not allowed, a new object (hereinafter referred to as “new data”) for correcting a previous object (hereinafter referred to as “old data”) is the map database. Consider the case of applying retroactively to the first period. In such a case, if the generation time of the map database is specified as the time information of the new data, in the database that does not allow duplication of the time information, the old data cannot be set with the time information and will be substantially deleted. Become. In this state, the old data cannot be used as necessary. On the other hand, in the present invention, duplication of time information is allowed, so that this adverse effect can be avoided. That is, it is possible to provide a map database in which both new data and old data can be used according to applications.

  The time information may be attached in units of objects having different issuance times or survey times, or may be attached to each item representing a shape or an attribute in the object. According to the former aspect, the amount of data can be suppressed. According to the latter aspect, the time information can be set finely for each item such as shape or attribute, and the shape and attribute at each time point can be expressed more appropriately.

  In order to make use of the above features, the object of the present invention may be capable of storing a plurality of coordinate data representing a position or shape. This object may or may not have the time information described above. In addition, when time information is included, the time information may or may not be allowed to overlap between objects of a plurality of times.

  Conventionally, a map database is usually created on the premise that the shape and position of an object are unchanged, and when the shape and position are changed, they are often handled as different objects. In contrast, by making it possible to store multiple types of coordinate data as described above, even when the shape or position of the object has changed, or even when the error included in the previous shape or position has been corrected The identity as an object can be maintained. Such a data structure is useful, for example, in avoiding erroneous processing or simplifying processing in surveys and statistical processing using a map across multiple ages.

  In the case of a data structure capable of storing a plurality of coordinate data, it is preferable to further include use control information used for properly using the plurality of coordinate data. For example, the time information shown above can be used as this usage control information. By doing so, it is possible to display a map using coordinate data with the latest time information, or to display a map with original data using the oldest coordinate data. Such a display can be effectively used in the following situations. For example, when a map database is used for various statistical processes, if the feature coordinate data is updated after the statistical process, the result of the statistical process may not match the map display. As described above, if the coordinate data can be used properly, in such a case, the cause can be found by displaying the map with the original data. The usage control information is not limited to information set in relation to the issue time and the like, and may be information related to the display purpose of the map, for example. As an example of this, as a plurality of shape data, normal map display shape data and deformed simplified map display shape data are prepared, and an index for properly using both of them according to the display purpose of the map is prepared. A mode attached as usage control information is conceivable. In addition to the examples illustrated here, various information that enables the use of a plurality of coordinate data can be used as the usage control information.

  In the present invention, it is preferable that the map database can be updated for each object. By doing so, the amount of data required for updating the map database can be reduced. For example, for a new event such as construction of a new building, a new object is simply added. On the other hand, if the accuracy of the old data has been improved or the old data has been corrected in the past when investigating the new data, this correction data is generated and the object management information attached to the object to be corrected In addition, time information including past time points to which the correction should be reflected may be added and added to the old data.

  The present invention is configured to be capable of storing a plurality of different types of data for at least some items of position, shape, and attributes, and has an object storing use control information used for properly using the plurality of types of data. It can also be configured as a map display device that displays a map using a map database. This map display device can perform map display using any of a plurality of types of data according to a predetermined condition using the use control information. For example, you may make it display a map using the data provided with the use control information corresponding to the conditions specified by the user, the time when displaying the map, the location of the terminal, the contents of the statistical processing specified from the terminal, etc. Depending on the conditions and purpose for displaying the map, the map may be displayed using different data.

  At this time, the map display device may accept designation of the reference time of map display, and display a map corresponding to the reference time with reference to the map database.

  As described above, old and new data may coexist as objects corresponding to the reference time. In such a case, the map display device of the present invention may use data of an object having the latest issue time or survey time among a plurality of objects having time information including the reference time. By doing so, even when old and new data coexist, an appropriate map using the latest data can be displayed.

  The map display device may enable display using an object other than the latest object described above under a predetermined condition. In this way, the old data can be used. As the predetermined condition, for example, a mode specified by the user, a mode in which display is performed according to a predetermined sequence, such as display using old data after display using new data, and the like can be adopted.

  The present invention does not have to include all of the various features described above, and can be configured by omitting some or combining them as appropriate. The present invention may be configured in a mode such as a map display method in which a map is displayed by a computer in addition to the above-described mode as a map display device. Moreover, it can also be comprised as a computer program for making a computer implement | achieve these methods, or it can comprise as a recording medium which recorded this computer program. Here, as a recording medium, a flexible disk, a CD-ROM, a magneto-optical disk, an IC card, a ROM cartridge, a punch card, a printed matter on which a code such as a barcode is printed, an internal storage device of a computer (RAM, ROM, etc. Various types of computer-readable media such as a memory) and an external storage device can be used.

Embodiments of the present invention will be described in the following order.
A. First embodiment:
A1. Device configuration:
A2. data structure:
A3. Map data update processing:
A4. Map display processing:
A5. Analysis processing:
B. Second embodiment:
B1. data structure:
B2. Map display processing:
C. Third embodiment:
C1. Device configuration:
C2. Map display processing:

A. First embodiment:
A1. Device configuration:
FIG. 1 is an explanatory diagram showing a schematic configuration of a map display device 100 as a first embodiment. In the first embodiment, the map display device 100 is configured by installing a computer program for realizing a map display function in a general-purpose personal computer. In the figure, each functional block configured by this computer program is illustrated. At least a part of these functional blocks may be configured in hardware. In the first embodiment, a stand-alone device will be described as an example. However, at least a part of the illustrated functional blocks may be provided from another computer or server via a network.

  In the first embodiment, map data used for map display is stored in the map DB 150. The map data is updated regularly or irregularly, and these updated versions are sequentially registered in the map DB 150. Here, for convenience of explanation, it is assumed that map data is issued / updated every year. In this embodiment, the map DB 150 is stored in a hard disk built in the personal computer. However, the map DB 150 may be stored in an external hard disk, a server connected via a network, a DVD, or other recording medium. In the present embodiment, the map DB 150 stores data relating to various events such as traffic accidents (hereinafter referred to as “event data”) in addition to map display data.

  The map DB management unit 130 updates map data stored in the map DB 150. That is, when the updated map data is provided on the recording medium 101 such as a DVD, the map DB management unit 130 reads the map data and stores it in the map DB 150. The updated map data may be provided via a network in addition to the recording medium 101. The map DB management unit 130 performs management such as reading of map data with respect to the map DB 150 and writing of the event data described above, including the above-described update.

  The analysis unit 120 performs statistical analysis using event data stored in the map DB 150. For example, analysis of changes in the occurrence of traffic accidents and regional statistics. The display control unit 140 performs map display using the map data of the map DB 150. An analysis result obtained by the analysis unit 120 can also be displayed.

  Commands necessary for the operations of the map DB management unit 130, the analysis unit 120, and the display control unit 140 can be input by the user through operations such as a keyboard and a mouse. The command input unit 110 inputs a command designated by the user through these operations, and delivers the command to the map DB management unit 130, the analysis unit 120, and the display control unit 140, respectively.

A2. data structure:
FIG. 2 is an explanatory diagram showing the structure of map data. An example of a map corresponding to map data is illustrated on the left side of the figure. Here, the data structure will be described by taking two types of 2004 version and 2005 version as an example. The map data of the present embodiment is stored as objects corresponding to various features such as roads and buildings. As shown on the right side of the figure, it is assumed that the data for the building BLDA is objects OBJ [1] and OBJ [2].

  Each object is given a unique object ID. In the example of the figure, the object ID is “BLDa”. Objects OBJ [1] and OBJ [2] having different issue times are associated with each other by this object ID.

  Each object includes shape data serving as map display data. The shape data in OBJ [1] is the point sequence data of the vertices A1 to A4 when the building BLDA is displayed as a polygon, and the coordinate values of the vertices A1 to A4 are stored. In addition to this, it is possible to include designation of a display color and a paint pattern for displaying an object in a polygon.

  In the object, attribute data and event data are also stored. Event data is data that records various social phenomena related to the object, such as the occurrence of a traffic accident, expansion / reconstruction, and the occurrence of an incident, together with the time of occurrence. As shown in the figure, the attribute data includes the type of object, the display name when displaying the object, the presence / absence of change, and the application time.

  The presence / absence of change represents the presence / absence of change from previous data. In the example of the figure, the 2005 version of the object OBJ [1] indicates that the object OBJ [2] before the 2004 version has changed. In the example of the figure, the case where there is a change in the shape data of the building BLDa is illustrated. In this example, in the 2004 version, the shape data is set to vertices a1 to a4, whereas in the 2005 version, the shape data is changed to vertices A1 to A4. Such a change may occur when an error is found in the measurement of the building shape, or when the building shape measurement accuracy is improved and more appropriate data is obtained in addition to when the building itself is renovated or renovated. . In this embodiment, including all these cases, the attribute data “changed” is set when there is any change in the object. In the figure, an example of whether or not there is a change is shown for the entire object OBJ [1], but the presence or absence of a change may be expressed for each item of shape data and attribute data.

  The application time indicates a time when each object data may be used, that is, a time when each object data is assumed to represent an actual geographical situation. In the example shown in the figure, it is assumed that the 2005 version of the object data OBJ [1] is obtained by the survey in September 2004. If the change in the shape data of the building BLDa is due to, for example, an improvement in measurement accuracy, the shape of the building BLDa has not actually changed. It is preferable to apply to previous map data. In such a case, as shown in the drawing, the application time is set to “before September 2004”. On the other hand, for example, if the survey result is September 2004, but the survey results are known to be usable after September 2000, "September 2000 and later" etc. As described above, the application time may be specified in a form starting from a time point earlier than the survey time. In addition, when the building BLDA is actually expanded or remodeled, the application period is set after the survey period, such as “September 2004 or later”, or after the completion of the expansion of the building BLDA. It will be.

  In this embodiment, as will be described later, if an object OBJ [1] “changed” is present in the updated map data, this change is reflected in the previous map data. In the example of the figure, the change in shape is reflected in the 2004 version of the object OBJ [2]. As a result of this reflection, correction data is added to the object OBJ [2] in addition to the original data, as shown in the figure. Instead of adding the correction data itself, link information such as an address where the object OBJ [1] is stored may be added. The contents of the correction data are the shape data indicating the new shape obtained in the 2005 version and the date and time when the correction was made. In this embodiment, the survey date and time of the 2005 version is recorded as the correction date and time, but the date when the correction data was actually added and the issue date of the map data of the 2005 version may be used.

  You may attach an application time to correction data itself. In this way, for example, the correction contents can be reflected from the middle of the time when the 2004 version should be used. Specifically, a case is considered where the 2004 version is the latest data from when the survey was conducted in September 2003 until the survey for the 2005 version was conducted in September 2004. For example, if it was found in the survey in September 2004 that the building was renovated in January 2004, the results of the expansion and renovation were added to the 2004 version as revised data, If "January and later" is set, the actual situation can be more appropriately reflected in the map data.

  In the example of the figure, an example in which new shape data is added to the object OBJ [2] while the original shape data remains is shown. On the other hand, a method of overwriting original shape data with new shape data may be adopted. However, the method of leaving the original shape data has an advantage that the map display using the original shape data can be performed as necessary.

  As described above, each time the map data is updated, when the past map data is reflected, the past map data may be corrected multiple times. In such a case, the correction data may be added sequentially at every update. Alternatively, the previous correction data may be deleted and overwritten with new correction data.

  In the present embodiment, an example is shown in which two types of information, that is, whether or not there is a change and the application time, are individually prepared. In addition, the presence / absence of a change may be expressed by an application time. For example, when the start time of the application time is earlier than the data issuance date or the survey date, it may be assumed that the change is “present” and the reflection processing to the past map data may be performed.

A3. Map data update processing:
FIG. 3 is a flowchart of the map data update process. This process is performed by the map DB management unit 130 (see FIG. 1), and is performed by the CPU of the personal computer in terms of hardware.

  When the process is started, the CPU reads the latest version of map data (step S10). Then, an object to be processed is selected from the objects included in the latest version of map data (step S11). A rule for selecting an object can be arbitrarily set.

  When the change “present” is set for the selected object (step S12), the CPU reflects the change in the past map data object according to the “application time”. This reflection is performed on an object having the same object ID as the selected object.

  An explanatory diagram of the reflection method is shown in the figure. For example, it is assumed that there is an object change in the 2005 version and the application time is set to “August 2003 or later”. In this case, since the application period is earlier than September 2003, which is the survey period of the 2004 version, the above changes are reflected in the 2004 version. As described above with reference to FIG. 2, if it is possible to set the application time “after August 2003” for the correction data, the change may be reflected in the 2003 version. When such setting is impossible, the reflection to the 2003 edition may be omitted.

  When the change “No” is set for the selected object (step S12), the CPU skips the above reflection. The CPU executes the above processing until it is finished for all objects included in the 2005 version (step S14). When the latest version of map data is issued by this process, not only the map data is added to the map DB 150 but also the changes made in the latest version can be reflected in the past map data. Therefore, for example, when an error in past map data or an improvement in accuracy is found, there is an advantage that past map data can be easily optimized simply by supplying the latest version of map data.

A4. Map display processing:
FIG. 4 is a flowchart of the map display process. This is a process executed by the display control unit 140 and the map DB management unit 130 (see FIG. 1). In this embodiment, not only the function of displaying a map at the present time but also the past map data is used to represent the geographical situation at a specific point in the past (hereinafter referred to as “display reference time”). It is also possible to display a map.

  When the map display process is started, the CPU inputs the display reference time (step S20), and reads the map data of the year version corresponding to this (step S21). As shown in the figure, when the display of the map at the time of April 2004 is designated by the user, that is, when the display reference time is April 2004, the latest version of the map data including this point is the 2004 version. Will be selected. This selection can be performed by a method of selecting the latest one of the map data whose survey date is earlier than the display reference time. The issue date may be used instead of the survey date.

  When the map data is selected in this way, the CPU next inputs a display mode (step S22) and displays a map (step S23). As the display modes, there are “original mode” and “latest mode”. The “latest mode” is a map display using correction data reflecting the correction (see FIG. 3) applied to each object when the map data is updated. The “original mode” is a map display using original objects, not correction data. The data used in each display mode is shown in the figure. As shown in OBJ [2] in FIG. 2, when correction is performed, correction data is added to the object in addition to the original data. When the original mode is specified, the map display using the original data is performed regardless of the presence or absence of the correction data. When the latest mode is specified, the map display using the correction data is performed. is there.

  In this embodiment, the latest mode is set as a default setting. By doing so, it is possible to display the most appropriate map without having to specify it at each display reference time. Each time the map display process is executed, the user may select the display mode, or the original mode may be set as the default setting.

A5. Analysis processing:
FIG. 5 is a flowchart of the analysis process. This process is executed by the analysis unit 120 and the map DB management unit 130 (see FIG. 1). Here, as shown in the diagram on the right side, a description will be given by taking as an example a case where the occurrence state of a traffic accident is recorded as event data on the road Ra. According to the 2004 version, the road Ra is bent halfway as shown by a broken line, and the number of accidents is recorded as 10 times. The number of accidents is the number of cases that occurred by the time of the investigation of the 2004 version, that is, the number that occurred mainly in FY2003. In the 2005 version, the road Ra is straightened as shown in practice, and the number of accidents is recorded as eight.

  When analysis processing is started, the CPU inputs analysis conditions (step S30). For example, the analysis conditions include the year to be analyzed, items, the regional range to be analyzed, and the like. Here, an example is shown in which a single object called road Ra is specified as a range, but the range may be specified by an administrative boundary name or the like, such as “XX city”.

  When the analysis condition is input, the CPU reads map data corresponding to this condition (step S31). As shown in the upper right figure, the shape of the road Ra and the number of accidents are read from the 2004 version and the 2005 version. Next, the CPU performs analysis according to the analysis conditions and outputs the result (step S32). An example of the output of analysis results is shown in the lower right figure. For example, as shown in the figure, it is possible to adopt a method of showing the transition of the number of traffic accidents and the improvement rate in the form of a graph or the like. The analysis result may be displayed together with the map on the upper right.

  From these displays, it can be seen that the change in the shape of the road Ra contributes to a reduction in the number of traffic accidents. The analysis method and the display mode of the map can be arbitrarily set according to the analysis item.

  FIG. 6 is an explanatory diagram showing another analysis example. The example which analyzed the traffic accident in the intersection of road B1 and B2 shown to a center figure was shown. It is assumed that building B is built near this intersection. As shown in the figure above, the number of traffic accidents has been 1 in 2003, 5 in 2004, and 4 in 2005. The number of traffic accidents increased with the construction of Building B. It is assumed that the result is obtained.

  The lower figure shows the contents of the building B object. In the 2004 version, the shape data is represented by b1 to b4, and in the 2005 version, the shape data is represented by B1 to B4. As shown in the center figure, according to the data of the 2004 version, it is assumed that the building B is at the position of a broken line, and according to the data of the 2005 version, the building B is at the position of a solid line. This difference is due to an error in measurement or an improvement in accuracy, and the contents of the 2005 version are reflected as correction data in the 2004 version.

  According to the data of the 2004 version, as shown in the center figure, the building B blocks the prospect line VL from the car Car1 traveling on the road B1 to the car Car2 traveling on the road B2. However, according to the data of the 2005 version, the building B does not exist at a position that blocks the see-through line VL. In this way, by reflecting the latest version of the map data in the past map data, an error in the analysis result that the building B contributes to the increase in the number of traffic accidents is found, and a more appropriate cause should be examined. Is possible.

  However, after the analysis results shown in the figure above are obtained, when the map data for the 2004 version is updated and the shape of the building B is represented by B1 to B4, As shown in the figure, the basis on which the analysis result that the building B is the cause is completely unknown. In this regard, in the present embodiment, even when the map data is corrected, the original data is retained. Therefore, the user selects the “original mode” to select the map using the previous map data. Can be displayed. As a result, in this embodiment, it is possible to recognize the influence of the correction of the map data on the analysis result, and it is possible to perform the analysis again.

  According to the map display device of the first embodiment described above, whenever the latest version of map data is issued, the contents can be appropriately reflected in the past map data. Therefore, it is possible to optimize the map data by going back to the past even when not only actual changes such as new construction of features but also data errors are found. The map data thus optimized can be used for various statistical analyzes using event data.

B. Second embodiment:
Next, a map display device as a second embodiment will be described. In the first embodiment, a case where map data is issued every year is illustrated. The second embodiment exemplifies a case where map data can be updated in units of objects. The apparatus configuration is the same as that of the first embodiment (see FIG. 1). However, in the second embodiment, the structure of the map data stored in the map DB 150 is different from the first embodiment.

B1. data structure:
FIG. 7 is an explanatory diagram showing the data structure of the second embodiment. In the lower right, an example of the object structure of the building BLDA is shown. In the present embodiment, the method of storing the data of each item using tags in the XML (eXtensible Markup Language) format is exemplified, but the structure of the object is not limited to this format.

  In the example shown in the figure, two sets of data OD1 and OD2 are stored in the object of the building BLDA. Data OD1 is original data of the object, and data OD2 is update data added in January 2005. In the original data OD1, the shape of the building BLDa is defined by a1 to a4, and in the update data OD2, it is defined by A1 to A4. As shown in the upper left figure, the positions of both are shifted. It is assumed that this is a change accompanying correction of errors or improvement in measurement accuracy during previous data measurement. In such a case, it is preferable to use the contents of the latest version of the data OD1 from the beginning, so that the valid period is from September 2003 when the object of the building BLDA was first generated. As a result, the effective period of the latest data OD1 completely overlaps with the effective period of OD2.

  The lower left figure illustrates how data overlaps. The original data OD1 can be used effectively after being set in September 2003, as indicated by a broken line. The latest data OD2 was issued in January 2005, and can be effectively used after January 2005, as indicated by a solid blank. However, as described above, since the contents of the latest data OD2 are preferably applied retroactively, the valid period is set so as to include a point in time past the issue date. As a result, the application time of the latest data OBJ2 is extended in the past by the hatched portion in the figure, and the valid period overlaps with the original data OD1. In the object of the second embodiment, data that contradict each other is allowed to exist for the same object with overlapping valid periods.

B2. Map display processing:
FIG. 8 is a flowchart of the map display process in the second embodiment. When the process is started, the CPU inputs the display mode at the time of the display reference as in the first embodiment (see FIG. 4) (step S120). As for the display mode, the latest mode and the original mode are prepared as in the first embodiment. Any one of the display modes may be set as a default. In this case, it is preferable in terms of convenience to set the latest mode as a default.

  Next, the CPU reads map data (step S121) and displays a map (step S122). The relationship between map data reading and display mode is shown in the figure. On the left side, the contents of the object of the building BLDA are shown. As described with reference to FIG. 7, the data added by updating the map data is the upper broken line frame portion, and the original data is the lower broken line frame portion.

  When the latest mode is designated as the display mode, data in the upper broken line frame is read. That is, the data with the latest issuance date is read from the data including the display reference time in the valid period. Whether or not it is the latest may be determined by the survey date instead of the issue date.

  When the original mode is designated, in the second embodiment, the latest data issued at the time of display reference is read. In the original mode, data having the oldest issue date, that is, data existing from the beginning for the object may be used. However, as described above with reference to FIG. 6, when the original mode is prepared mainly for confirming the basis for the analysis result performed in the past, as described in the second embodiment, the display standard is used. It is preferable to use the latest data from the published data.

  According to the second embodiment, the map can be displayed at an arbitrary display reference time as in the first embodiment. Similarly to the first embodiment, by holding event data for each object, it can be used for analysis of various statistics.

  In the second embodiment, when the map data is updated, the valid period is allowed to overlap between the previous data and the latest data. By doing this, map data can be updated by simply adding update data without making any changes to the previous data, and this has the advantage of reducing the processing load during the update. Of course, in the second embodiment, at the time of data update, the latest data issue date or survey date may be set as the end of the valid period of the previous data. However, according to the map display process of the second embodiment, the data most suitable for the display mode designated by the user can be selected and used from the data existing in the object during map display. Therefore, it can be said that the necessity of attaching the end of the effective period is low.

  In the second embodiment, the process shown in the map display (FIG. 8), that is, the process of selectively using the data according to the latest mode and the original mode based on the issue date and the valid period in the object is not limited to the map display. The present invention can be applied to various processes that use objects such as processing.

C. Third embodiment:
C1. Device configuration:
FIG. 9 is an explanatory diagram showing a device configuration of a map display device as a third embodiment. In the third embodiment, the data shown in the first embodiment, that is, the map data prepared separately for each fiscal year, and the data shown in the second embodiment, that is, the object is not divided for each issuing year. The case where the data managed together in FIG.

  Similar to the first embodiment, the map display device is configured by installing a computer program in a general-purpose personal computer. In the figure, functional blocks configured as software are illustrated, but at least a part of these may be configured as hardware.

  The functions of the command input unit 110A, the analysis unit 120A, and the display control unit 140A are the same as those in the first embodiment (FIG. 1). The present embodiment is different from the first embodiment in that the map DB 150A contains both map data stored in the year version and the object data. In the example in the figure, the 2002 version and the 2003 version are stored as map data generated separately for each year (hereinafter referred to as “year version DB”), and are later than the 2003 version. Map data is held as an objectized DB as shown in the second embodiment.

  The map data in the objectized DB can be updated in units of objects as shown in the second embodiment. It is possible to use a common object ID for the same feature in the objectized DB and the year version DB. However, in this embodiment, the data version is different between the year version DB and the object DB, and therefore different objects are used. Assume that an ID is attached. Further, it is assumed that the objectized DB is generated on the assumption that the year version DB exists, and holds only the update data from the year version DB. Of course, it is also possible to prepare as a data that can display a complete map only by the objectified DB.

  The map DB management unit 130A is the same as that of the first embodiment in that it includes addition of update data and reads / writes to / from the map DB 150A. However, in the third embodiment, it is necessary to access different types of map data, that is, the year version DB and the object DB. As described above, the year version DB and the objectized DB are associated with different object IDs even if they are the same feature. In the third embodiment, this association is defined by the ID conversion table 131A.

  The contents of the ID conversion table 131A are shown on the right side of the figure. In this example, it is assumed that for a certain feature, the ID in the objectified DB is “BLLa_obj” and the ID in the yearly version DB is “BLDA”. In the ID conversion table 131A, as shown in the figure, the ID “BLDa” in the year version DB and the ID “BLDa_obj” in the objectification DB are stored in association with each other. In the figure, only the correspondence relationship for one object is illustrated, but the same applies to other objects.

  The map DB management unit 130A can access both the year version DB and the object version DB as necessary by referring to the ID conversion table 131A. For example, when new update data is received, the update data is added to the objectification DB, and the corresponding object is detected in the year version DB by referring to the ID conversion table 131A, and the update data is reflected. It becomes possible.

C2. Map display processing:
FIG. 10 is a flowchart of the map display process in the third embodiment. When the process is started, the CPU inputs the display reference time and the display mode (step S220). If the display reference time is before the issuance of the objectized DB, that is, if there is a year version DB corresponding to the display reference time, the map display processing is the same as in the first embodiment (see FIG. 4). Accordingly, in the following, an example of processing when the point in time after issuance of the objectified DB is designated as the display reference time will be exemplified.

  When the original mode is designated (step S221), the CPU reads the latest data issued at the time of the map display reference (step S225) and displays the map (step S226), as in the second embodiment. .

  If the latest mode has been designated (step S221), the latest year version map data and object data are read (steps S222 and S223). In the example of FIG. 9, the 2003 map data and the object database are read. Then, the CPU refers to the ID conversion table 131A, replaces the object of the year version map data with the data of the objectized DB (step S224), and performs map display (step S226). By doing so, the map display reflecting the latest data in the object DB can be performed while the data lacking in the object DB is supplemented by the year DB.

  As mentioned above, although the various Example of this invention was described, it cannot be overemphasized that this invention is not limited to these Examples, and can take a various structure in the range which does not deviate from the meaning.

It is explanatory drawing which shows schematic structure of the map display apparatus 100 as 1st Example. It is explanatory drawing which shows the structure of map data. It is a flowchart of a map data update process. It is a flowchart of a map display process. It is a flowchart of an analysis process. It is explanatory drawing which shows the other example of analysis. It is explanatory drawing which shows the data structure of 2nd Example. It is a flowchart of the map display process in 2nd Example. It is explanatory drawing which shows the apparatus structure of the map display apparatus as 3rd Example. It is a flowchart of the map display process in 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 100A ... Map display apparatus 101 ... Recording medium 110, 110A ... Command input part 120, 120A ... Analysis part 130, 130A ... Map DB management part 131A ... ID conversion table 140, 140A ... Display control part 150, 150A ... Map DB

Claims (10)

A data structure of a map database for storing map data composed of a plurality of objects,
Object management information for identifying each object;
Corresponding with the object management information, and objects of a plurality of periods with different issuance periods or survey periods,
Time information that individually represents the time geography of each object,
The time information is a data structure that is allowed to overlap between the objects of the plurality of times. A data structure according to claim 1, wherein
The time information is a data structure attached to each item representing the shape or attribute. A data structure according to claim 1 or 2, wherein
The object has a data structure capable of storing a plurality of coordinate data representing a position or a shape. A data structure of a map database for storing map data composed of a plurality of objects,
Object management information for identifying each object;
It is associated with the object management information, and has an object of a plurality of periods with different issuance periods or survey periods,
The object has a data structure capable of storing a plurality of coordinate data representing a position or a shape. A data structure according to claim 3 or 4,
The object has a data structure having use control information used for properly using the plurality of types of coordinate data. A map display device that displays a map using a map database,
The map database is
A data structure of a map database for storing map data composed of a plurality of objects,
Object management information for identifying each object;
A plurality of objects that are associated with the object management information and have different issuance periods or survey periods;
The object is configured to be capable of storing a plurality of different types of data for at least some items of position, shape, and attribute, and stores use control information used for properly using the plurality of types of data,
The map display device
A map database reference unit for referring to the map database;
A display control unit that performs map display based on the map database;
The said display control part is a map display apparatus which performs the said map display using either of the said several types of data by the predetermined conditions using the said usage control information. A map display device that displays a map using a map database,
The map database is
A data structure of a map database for storing map data composed of a plurality of objects,
Object management information for identifying each object;
A plurality of objects associated with the object management information and having different issuance periods or survey periods;
Time information that individually represents when the object fits the geography of the time,
The time information is a database that is allowed to overlap between the objects of the plurality of times,
The map display device
A reference time input section for accepting a map display reference time specification;
A map database reference unit for referring to the map database;
A display control unit that performs map display based on the map database;
The display control unit is a map display device that uses an object having the latest issue time or survey time among the objects having time information including the reference time. The map display device according to claim 7,
The said display control part is a map display apparatus in which the display using objects other than the said latest object is possible on predetermined conditions. A computer program for displaying a map using a map database,
The map database is
A data structure of a map database for storing map data composed of a plurality of objects,
Object management information for identifying each object;
A plurality of objects that are associated with the object management information and have different issuance periods or survey periods;
The object is configured to be capable of storing a plurality of different types of data for at least some items of position, shape, and attribute, and stores use control information used for properly using the plurality of types of data,
The computer program is
A function of referring to the map database;
A display function for displaying a map based on the map database can be realized by a computer,
The display control function is a computer program which is a function for performing the map display using any of the plurality of data according to a predetermined condition using the use control information. A computer program for displaying a map using a map database,
The map database is
A data structure of a map database for storing map data composed of a plurality of objects,
Object management information for identifying each object;
A plurality of objects associated with the object management information and having different issuance periods or survey periods;
Time information that individually represents when the object fits the geography of the time,
The time information is a database that is allowed to overlap between the objects of the plurality of times,
The computer program is
A function that accepts specification of the standard time of map display,
A function of referring to the map database;
A display control function for displaying a map based on the map database can be realized by a computer,
The display control function is a computer program for displaying a map using an object having the latest issue time or survey time among the objects having time information including the reference time.