Patent Publication Number: US-2017350710-A1

Title: Computer-readable recording medium, method, and apparatus for storing traveling data

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. continuation application filed under 35 USC 111(a) claiming benefit under 35 USC 120 and 365(c) of PCT application PCT/JP2016/050708, filed on Jan. 12, 2016, which claims priority to Japanese Patent Application Ser. No. 2015-036901, filed in Japan on Feb. 26, 2015. The foregoing applications are hereby incorporated herein by reference. 
    
    
     FIELD 
     The embodiment discussed herein is related to a computer-readable recording medium, method, and apparatus for storing traveling data. 
     BACKGROUND 
     Conventionally, as part of maintenance and repair of roads, a technology has been known to travel on the road with a mobile device mounted on a survey vehicle that investigates a state of a road surface and the like, and to render a route traveled on a map according to position information collected by the mobile device at predetermined time intervals. 
     [Patent Document 1] 
     Japanese Laid-open Patent Publication No. 2011-53226 
     SUMMARY 
     According to one aspect of the embodiment, there is provided a non-transitory computer-readable recording medium that stores a traveling data storing program that causes a computer to execute a process including: receiving first traveling data, in which data of latitude and longitude of a vehicle acquired at predetermined time intervals from a departure point to an arrival point correspond to time when the data of the latitude and the longitude are acquired; reading out three or more consecutive sets of data of the latitude and the longitude in time from the first traveling data; generating second traveling data by control through deleting data existing within a predetermined range from a straight line connecting two points at both ends of the three or more consecutive sets of data of the latitude and the longitude in time; and storing the generated second traveling data in a storage device. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a traveling data storing system; 
         FIG. 2  is a first diagram for briefly explaining a process for thinning point data of points other than a start point and an end point on a straight line portion; 
         FIG. 3  is a second diagram for briefly explaining the process of thinning the point data of the points other than the start point and the end point on a straight line portion; 
         FIG. 4  is a diagram illustrating an example of a hardware configuration of a traveling data storing server; 
         FIG. 5  is a diagram illustrating an example of a traveling data database; 
         FIG. 6  is a diagram for explaining functions of the traveling data storing server; 
         FIG. 7A  and  FIG. 7B  are diagrams for explaining a relationship between a distance from the straight line connecting the start point and the end point to a middle point among three points and an absolute value of a calculation result of a straight line formula; 
         FIG. 8  is a flowchart for explaining operations of the traveling data storing server; 
         FIG. 9  is a diagram for explaining the operation of the traveling data storing server; 
         FIG. 10  is a diagram illustrating an example of a rendering traveling database for rendering; and 
         FIG. 11  is a flowchart for explaining a process conducted by the rendering process part. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In a related art, when rendering a traveling route, since all sets of position information acquired by a mobile device are used, a load of a rendering process is high. 
     Therefore, in one aspect, it is an object to provide a computer-readable recording medium, method, and apparatus for reducing a processing load when rendering a route. 
     In the following, embodiments of the present invention will be described with reference to the accompanying drawings.  FIG. 1  is a diagram illustrating an example of a traveling data storing system. 
     A traveling data storing system  100  in the present embodiment includes a traveling data storing server  200 , and a mobile device  300 . The traveling data storing server  200  is connected to the mobile device  300  through a network or the like. 
     The traveling data storing server  200  in the present embodiment includes a traveling database  210 , a rendering traveling database  220 , a traveling data storing process part  230 , and a rendering process part  240 . 
     For instance, the mobile device  300  in the present embodiment is mounted in a vehicle  10  or the like for surveying a road state while traveling on a road, and acquires location information of the vehicle  10  at predetermined time intervals. Next, the mobile device  300  sends a set of point data in which the location information corresponds to time when the location information is acquired, to the traveling data storing server  200 . The location information in the present embodiment is indicated by latitude and longitude, and is acquired by a Global Positioning System (GPS) including the mobile device  300 . 
     The traveling data storing server  200  in the present embodiment stores the traveling data when receiving the traveling data from the mobile device  300 . 
     Also, the traveling data storing server  200  in the present embodiment thins out the point data of points other than a start point and an end point on a straight line portion on the traveling route from the traveling data stored in the traveling database  210 . Then, the traveling data storing server  200  stores a set of remaining point data, which have not been excluded (deleted) in this process, as rendering traveling data in the rendering traveling database  220 . 
     In other words, the traveling data storing server  200  in the present embodiment generates second traveling data by deleting the point data of points other than the start point and the end point on a straight line on the traveling route from first traveling data being received, and stores the second traveling data in the rendering traveling database  220 . 
     Accordingly, in the present embodiment, the rendering traveling data are reduced in data amount relative to the traveling data. 
     Also, the traveling data storing server  200  in the present embodiment receives a display request of the traveling route of the vehicle  10  from a terminal device  400 , and has a rendering process part  240  refer to the rendering traveling database  220 . The rendering process part  240  generates screen data for a screen on which the traveling route is rendered on a map, based on the rendering traveling database  220 , and sends the generated screen data to the terminal device  400 . 
     That is, in the present embodiment, when rendering the traveling route, a rendering process is conducted based on the rendering traveling data in which the data amount of the traveling data is reduced. Hence, according to the present embodiment, it is possible to reduce the data amount to be read for the rendering process. Furthermore, in order to conduct the rendering process by reduced data, it is possible to reduce the load of the rendering process. 
     In the example depicted in  FIG. 1 , the terminal device  400  is not included in the traveling data storing system  100 ; however, the terminal device  400  may be included in the traveling data storing system  100 . 
     Moreover, in the example depicted in  FIG. 1 , a destination to send the screen data in which the traveling route is rendered is, but is not limited to, the terminal device  400 . For instance, in a case of receiving the display request of the traveling route of the vehicle  10  from the mobile device  300 , the traveling data storing server  200  may send the screen data to the mobile device  300  or may display a screen rendering the traveling route on a display device of the traveling data storing server  200 . 
     Also, in the example depicted in  FIG. 1 , the traveling data storing server  200  receives the traveling data from the mobile device  300 ; however, the present embodiment is not limited thereto. Alternatively, for instance, the traveling data storing server  200  in the present embodiment may read out the traveling data from a recording medium or the like storing the traveling data acquired by the mobile device  300 . 
     Also, in the example depicted in  FIG. 1 , the rendering process part  240  is provided in the traveling data storing server  200 ; however, the present embodiment is not limited thereto. Alternatively, for instance, the mobile device  300  or the terminal device  400  may include the rendering process part  240 . In such a case, for instance, the traveling data storing server  200  may instruct the rendering process part  400  to refer to the rendering traveling database  220  upon receiving the display request of the traveling route of the vehicle  10 . 
     In the following, with reference to  FIG. 2  and  FIG. 3 , a process for thinning the point data of the points other than the start point and the end point on the straight line portion will be described. 
       FIG. 2  is a first diagram for briefly explaining the process for thinning the point data of the points other than the start point and the end point on the straight line portion. 
     In the present embodiment, the traveling route is rendered by using only the point data of the start point and the point data of the end point on a straight line, and the point data of points representing a curve, in the traveling data stored in the traveling database  210 . 
     In the example depicted in  FIG. 2 , a traveling route R 1  includes a straight line L 1 , a curve C 1 , and a straight line L 2 . In this case, in the present embodiment, the point data of points between a start point P 1  and an end point P 2  on the straight line are excluded. Also, in the present embodiment, the point data of a point P 3  between a start point P 2  of the curve C 1  and an end point P 4  of the curve C 1  are not excluded. In the present embodiment, the same manner is applied to a straight line L 2 , and the point data of points between the start point P 4  and the end point P 5  of the straight line L 2 . 
     Accordingly, the point data of points P 1 , P 2 , P 3 , P 4 , and P 5  are regarded as the rendering traveling data for the traveling route R 1  illustrated in  FIG. 2 . Regarding the point data of points P 1  to P 5 , the point data of points between the point P 1  and the point P 2  and the point data of points between the point P 4  and the point P 5  are excluded. 
       FIG. 3  is a second diagram for briefly explaining the process of thinning the point data of the points other than the start point and the end point on a straight line portion. 
     The traveling data storing server  200  in the present embodiment selects three sets of the point data from the traveling database  210  (step S 1 ). The three sets of the point data selected in step S 1  are the point data of a point  31  indicated by n-th location information, the point data of a point  32  indicated by n+1-th location information, and the point data of a point  33  indicated by n+2-th location information, which are acquired by the mobile device  300 . 
     In the following, the point data, in which an order of acquiring the location information is continuous, are called “consecutive point data”. In the present embodiment, among three consecutive sets of the point data, the point data of the point  31  that is the start point are set as point data for a not-excluded subject. The point data of a not-excluded subject correspond to point data that are confirmed as being stored in the rendering traveling database  220 . 
     Successively, the traveling data storing server  200  determines whether three selected points are on the same straight line (step S 2 ). 
     In step S 2 , in a case in which the three points are on the same straight line, the traveling data storing server  200  determines the point data of the point  32  located in the middle among the three points  31 ,  32 , and  33 , as an excluded subject. Next, the traveling data storing server  200  selects a point  34  continuous from the point  33 , and goes back to step S 2  (step S 3 ). In the present embodiment, the point data determined as an excluded subject are not stored in the rendering traveling database  220 . 
     In step S 2 , in a case in which the three points are not on the same straight line, the traveling data storing server  200  determines the point data of the point  32  as point data for a not-excluded subject. Then, the traveling data storing server  200  selects three consecutive points  32 ,  33 , and  34  with the point  32  as the start point, and goes back to step S 2  (step S 4 ). 
     By repeating this process, the traveling data storing server  200  in the present embodiment creates the rendering traveling database  220 , which excludes the point data other than the start point and the end point on the straight line from the traveling data. 
     Next, referring to  FIG. 4 , a hardware configuration of the traveling data storing server  200  in the present embodiment will be described.  FIG. 4  is a diagram illustrating an example of a hardware configuration of the traveling data storing server. 
     The traveling data storing server  200  in the present embodiment includes an input device  21 , an output device  22 , a drive device  23 , an auxiliary storage device  24 , a memory device  25 , a processor as an arithmetic processing unit  26 , and an interface device  27 , which are mutually connected via a bus B. 
     The input device  21  includes a keyboard, a mouse, and the like, and is used to input various signals. The output device  22  includes a display device, or the like, and is used to display various windows, data, and the like. The interface device  27  includes a modem, a Local Area Network (LAN), or the like, and is used to connect to the network. 
     A traveling data storing program is at least a part of various programs controlling the traveling data storing server  200 . For instance, the traveling data storing program may be provided by distributing a recording medium  28  or by being downloaded through the network. As the recording medium  28  recording the traveling data storing program, various types of recording media may be used: a recording medium optically, electrically, or magnetically recording information such as a Compact Disc Read only memory (CD-ROM), a flexible disc, an magnetic optical disk, or the like, a semiconductor memory such as a Read-Only Memory (ROM), a flash memory, or the like. That is, the recording medium  28  may be any type of a recording medium, which is a non-transitory tangible computer-readable medium including a data structure. 
     Also, when the recording medium  28  recording the traveling data storing program is set to the drive device  23 , the traveling data storing program is installed to the auxiliary storage device  24  through the drive device  23  from the recording medium  28 . The traveling data storing program downloaded through the network is installed to the auxiliary storage device  24  via the interface device  27 . 
     The auxiliary storage device  24  stores files, data, and the like as well as the installed traveling data storing program. The memory device  25  reads out and stores the traveling data storing program from the auxiliary storage device  24  when the computer that is the traveling data storing server  200  is activated. Then, the arithmetic processing unit  26  realizes various processes described later, in accordance with the traveling data storing program stored in the memory device  25 . 
     Also, for instance, the mobile device  300  and the terminal device  400  in the present embodiment may be general computers, tablets, or the like; hardware configurations thereof may be the same as that of the traveling data storing server  200 . In a case in which the mobile device  300  is a tablet, a smart phone, or the like, the mobile device  300  may include a display operation device including a display function, instead of the input device  21  and the output device  22 . 
       FIG. 5  is a diagram illustrating an example of the traveling data database. The traveling database  210  is provided to correspond to the vehicle  10 , and identification information or the like is used to specify the vehicle  10 . Accordingly, when receiving the traveling data for multiple vehicles, the traveling data storing server  200  includes a number of sets of the traveling database  210  matching a number of the multiple vehicles. 
     For instance, the traveling database  210  may be provided in the auxiliary storage device  24  or the like of the traveling data storing server  200 . 
     The traveling database  210  in the present embodiment includes information items of “DATA NUMBER”, “DATE”, “TIME”, “LATITUDE”, “LONGITUDE”, and the like. In the present embodiment, a value of the item “DATA NUMBER” corresponds to a value of other items. In the following, information including the value of the item “DATA NUMBER” and values of the other items may be simply called “point data”. Moreover, in the following, a pair of the items “LATITUDE” and “LONGITUDE” may be called “location information”. That is, the point data include the location information. 
     The value of the item “DATA NUMBER” is regarded as an identification for specifying the point data. A value of the item “DATE” indicates a date when values of the items “LATITUDE” and “LONGITUDE” are acquired. A value of the item “TIME” indicates a time when the values of the items “LATITUDE” and “LONGITUDE” are acquired. The values of the items “LATITUDE” and “LONGITUDE” indicate the latitude and the longitude acquired by the mobile device  300  at predetermined time intervals. 
       FIG. 6  is a diagram for explaining functions of the traveling data storing server. The traveling data storing server  200  in the present embodiment includes the traveling data storing process part  230  and the rendering process part  240 . The traveling data storing process part  230  in the present embodiment is realized by the arithmetic processing unit  26  of the traveling data storing server  200  executing the traveling data storing program. For instance, the rendering process part  240  is realized by the arithmetic processing unit  26  of the traveling data storing server  200  executing a rendering program. 
     The traveling data storing process part  230  in the present embodiment includes a traveling data reception part  231 , a point selection part  232 , a straight line formula calculation part  233 , an exclusion determination part  234 , and a rendering point data storage part  235 . 
     The traveling data reception part  231  in the present invention receives an input of the traveling data and stores the traveling database  210 . 
     The point selection part  232  refers to the traveling database  210 , and selects three points to be subjects for a determination process conducted by the exclusion determination part  234  described later, sequentially from a point to be the start point (a departure point) of the traveling route indicating the traveling data. 
     The straight line formula calculation part  233  acquires the location information of three points selected by the point selection part  232 , and calculates values in order to determine whether the three points are on the same straight line. The exclusion determination part  234  determines whether the point data of the point in the middle of three points are to be the excluded subject or the not-excluded subject, based on the calculated values. 
     That is, the point selection part  232 , the straight line formula calculation part  233 , and exclusion determination part  234  in the present embodiment serve as a generation part  250 . The straight line formula calculation part  233  and the exclusion determination part  234  will be described later. 
     The rendering point data storage part  235  stores the point data of points, which are determined as not-excluded subjects by the exclusion determination part  234 . 
     The rendering process part  240  in the present embodiment includes a screen data generation part  241 , and a screen data output part  242 . When receiving the display request of the traveling route of the vehicle  10 , the screen data generation part  241  in the present embodiment refers to the rendering traveling database  220 , and generates the screen data for the screen in which the traveling route of the vehicle  10  is rendered on the map. 
     The screen data output part  242  sends the screen data generated by the screen data generation part  241  to a device sending the display request of the traveling route. 
     In the following, processes of the straight line formula calculation part  233  and the exclusion determination part  234  in the present embodiment will be described. 
     For a case with coordinates (Xa, Ya) of a point A, coordinates (Xb, Yb) of a point B, and coordinates (Xc, Yc) of a point C, if the following formula (1) is satisfied: 
         Ya ( Xb−Xc )+ Yb ( Xc−Xa )+ Yc ( Xa−Xb )=0   (1),
 
     the three points A, B, and C are mathematically determined as being on the same straight line. In order to determine that the three points A, B, and C are on the same straight line, the above formula (1) may be a necessary and sufficient condition. 
     In the present embodiment, the formula (1) is called “straight line formula”. For the formula (1), it is assumed that an X-axis and a Y-axis have scale units, grid lines are drawn according to scale units of the X-axis and the Y-axis, and lattices in a coordinate plane form squares. 
     However, in the present embodiment, the latitude and the longitude are used as coordinate axes. Hence, a length per latitude of 1 degree and a length per longitude of 1 degree may not be the same. That is, in a case of using the latitude and the longitude as coordinate axes, the lattices in the coordinate plane are often not squares; accordingly, generally, a calculation result of the straight line formula does not become 0. 
     Moreover, in the present embodiment, it is assumed to determine whether the traveling route of the vehicle  10  is the straight line. For instance, in this determination, even in a case in which the traveling route of the vehicle  10  is meandering due to a lane change, it is preferable to regard the traveling route as the straight line as long as a meandering width is within a road width. 
     In the present embodiment, in consideration of these points, based on a relationship between a distance from a straight line connecting the start point and the end point to a middle point among the three points and an absolute value of the calculation result of the straight line formula, a threshold, which is used to determine whether the three points are on the same straight line, is defined. Accordingly, in the present embodiment, when the absolute value of the calculation result of the straight line formula is less than or equal to the threshold, the three points are regarded as being on the same straight line. 
       FIG. 7A  and  FIG. 7B  are diagrams for explaining the relationship between the distance from the straight line connecting the start point and the end point to the middle point among three points and the absolute value of the calculation result of the straight line formula. In the example depicted in  FIG. 7A  and  FIG. 7B , the lattices on the coordinate plane form the squares. 
       FIG. 7A  illustrates an example of a case in which the point A is located at coordinates (1, 1), the point B is located at coordinates (2, 3), and the point C is located at coordinates (3, 3). 
     In this case, with an absolute value of the calculation result of the straight line formula being defined as β, the absolute value β of the calculation result of the straight line formula indicates 2. Moreover, a distance d from a straight line  71  connecting the point A and the point C to the point B is √2/2. 
     Accordingly, the relationship between the absolute value β of the calculation result of the straight line and the distance d is expressed by a formula (2) below: 
       β=2√2d   (2).
 
       FIG. 7B  is a diagram illustrating an example of a case in which the point A is located at coordinates (1, 1), the point B is located at coordinate (3, 1), and the point C is located at coordinate (3, 3). In this case, the above formula (2) also indicates the relationship between the absolute value β of the calculation result of the straight line formula and the distance d. 
     That is, from these examples described above, the relationship between the absolute value β of the calculation result of the straight line formula and the distance d is represented by the above formula (2). 
     Accordingly, in the present embodiment, by setting the distance d, the threshold is determined with respect to the absolute value β of the calculation result of the straight line formula. 
     For instance, when the distance d=1[m], the absolute value β of the calculation result of the straight line formula=2.8 (rounded down to two decimal places). Accordingly, in the present embodiment, in a case in which the middle point of the three points is located within a width 2 [m] from the straight line connecting the start point and the end point of the three points defined as a center, in order to determine that the three points are on the same straight line, the threshold may be defined as 2.8 [m] with respect to the absolute value β of the calculation result of the straight line formula. 
     In this case, in the present embodiment, if the absolute value β of the calculation result of the straight line formula is less than or equal to 2.8 [m], the three points are determined as being on the same straight line. 
     Moreover, for instance, in a case of detecting the straight line portion from the traveling route without consideration of the lane change in a straight road including two lanes on each side, in which each of the lanes is 3.5 m in width, d=3.5 may be defined and the threshold may be defined as 9.9 with respect to the absolute value β of the calculation result of the straight line formula. 
     As described above, in the present embodiment, in a case of the middle point of the three points being within a predetermined range from the straight line connecting the start point and the end point, these three points are determined as being on the same line, and the point data of the middle point is regarded as the excluded subject. Moreover, in the present embodiment, in a case in which the middle point is out of the predetermined range from the straight line connecting the start point and the end point, it is determined that these three points are not on the same straight line and the point data of the middle point is set as the not-excluded subject. 
     In other words, when the absolute value β of the calculation result of the straight line formula calculated by the straight line formula calculation part  233  is less than or equal to the threshold, the exclusion determination part  234  in the present embodiment determines the three points as being on the same line, and sets the point data of the middle point as the excluded subject. Moreover, when the absolute value β of the calculation result of the straight line formula calculated by the straight line formula calculation part  233  is greater than or equal to the threshold, the exclusion determination part  234  in the present embodiment determines that these three points are not on the same straight line, and sets the point data of the middle point as the not-excluded subject. 
     In the following, operations of the traveling data storing server  200  in the present embodiment will be described with reference to  FIG. 8 . 
       FIG. 8  is a flowchart for explaining the operations of the traveling data storing server. The traveling data storing server  200  in the present invention refers to the traveling database  210  in which the traveling data received by the traveling data reception part  231  are stored (step S 801 ). Subsequently, the traveling data storing server  200  determines, by the exclusion determination part  234 , the point data of a beginning point in the traveling database  210  as the not-excluded subject (step S 802 ). The point data of the beginning point is the point data of the start point of the traveling route. 
     Next, the traveling data storing server  200  selects, by the point selection part  232 , three consecutive points from the beginning in the traveling database  210  (step S 803 ). Successively, the traveling data storing server  200  acquires, by the straight line formula calculation part  233 , the location information (the latitude and the longitude) of the three points based on the point data of the selected three points (step S 804 ). 
     Next, the traveling data storing server  200  substitutes the acquired location information of the three points to the straight line formula, and calculates the absolute value β of the calculation result of the straight line formula (step S 805 ). 
     Next, the traveling data storing server  200  determines, by the exclusion determination part  234 , whether the absolute value β of the calculation result of the straight line formula is less than or equal to the threshold defined beforehand (step S 806 ). In step S 806 , when the absolute value β is greater than the threshold, the traveling data storing server  200  advances to step S 810  described later. In step S 806 , when the absolute value β is less than or equal to the threshold, the exclusion determination part  234  determines the point data of a second point (the middle point) among the three points, as the point data of the excluded subject (step S 807 ). 
     Following step S 807 , the traveling data storing server  200  determines, by the point selection part  232 , whether next point data exist in the traveling database  210  (step S 808 ). In step S 808 , when the next point data do not exist, the traveling data storing server  200  advances to step S 813  described later. 
     In step S 808 , when the next point data exist, the traveling data storing server  200  selects, by the point selection part  232 , one point ahead of a third point among three points selected in step S 803 , sets a first point, the third point, and a fourth point as new three points (step S 809 ), and goes back to step S 804 . That is, the point selection part  232  reads out the point data of the fourth point at continuous time, and sets the first point, the third point, and the fourth point as new three points. 
     In step S 806 , when the absolute value β is greater than the threshold, the traveling data storing server  200  determines the point data of a second point (the middle point) among the three points as the point data of the not-excluded subject (step S 810 ). 
     Next, the traveling data storing server  200  determines, by the point selection part  232 , whether next point data exist in the traveling database  210  (step S 811 ). In step S 811 , when next point data do not exit, the traveling data storing server  200  advances to step S 813 . 
     In step S 811 , when next point data exist, the traveling data storing server  200  selects, by the point selection part  232 , one point ahead of a third point among the three points selected in step S 803 , sets a second point, the third point, and a fourth point as new three points (step S 812 ), and goes back to step S 804 . 
     In step S 808  and step S 811 , for cases in which next point data do not exist, the traveling data storing server  200  determines, by the exclusion determination part  234 , the point data of the third point as the point data of the not-excluded subject (step S 813 ). The point data of the third point in step S 813  correspond to the point data of an end of the traveling database  210 , that is, the point data of the end point (an arrival point) of the traveling route. 
     Next, the traveling data storing server  200  stores, by the rendering point data storage part  235 , the point data determined as the not-excluded subjects in the rendering traveling database  220  (step S 814 ), and terminates this process. 
     In the following, a process of the traveling data storing server  200  in the present embodiment will be described with reference to  FIG. 9  and  FIG. 10 . 
       FIG. 9  is a diagram for explaining the operation of the traveling data storing server. The traveling data storing server  200  in the present embodiment determines, by the point selection part  232 , the point data of the beginning of the traveling database  210  as the not-excluded subject. The point data of the beginning of the traveling database  210  in the present embodiment correspond to the point data of a data number “1” (refer to  FIG. 5 ). In this case, the point data of the data number “1” correspond to the point data of the start point of the traveling route. 
     Next, the point selection part  232  selects three sets of the point data from the data number “1” to a data number “3” in the traveling database  210 , and acquires a value of the latitude and a value of the longitude from each sets of the point data. Then, the straight line formula calculation part  233  acquires the absolute value β of the calculation result of the straight line formula, and the exclusion determination part  234  determines whether the point data of the data number “2” is to be the not-excluded subject. 
     In the example illustrated in  FIG. 9 , a point indicated by the point data of the data number “2” is determined as being on the same straight line as the points indicated by the point data of the data numbers “1” and “3”. Hence, the point indicated by the point data of the data number “2” is determined as the point data for the excluded subject. 
     Next, the point selection part  232  selects the data number “1”, the data number “3”, and a data number “4” as the next point data after the point data of the data number “3”, conducts a similar process, and determines whether the data number “3” is the excluded subject. 
     In the example illustrated in  FIG. 9 , it is determined that the point indicated by the point data of the data number “3” does not exist on the same straight line on which the points indicated by the point data of the data numbers “1” and “4” are located. Hence, the point indicated by the point data of the data number “3” is determined as the point data for the not-excluded subject. 
     Next, the point selection part  232  selects three sets of the point data sequentially from the point data of the data number “3”, which is determined as the next point data of the not-excluded subject after the data number “1”. Hence, in this case, the point data of the data numbers “3” through “5”. 
     The traveling data storing server  200  conducts a similar process regarding these three sets of the point data, and determines whether the data number “4” is the excluded subject. 
     In the example illustrated in  FIG. 9 , it is determined that the point indicated by the point data of the data number “4” is located on the same straight line on which the points indicated by the point data of the data numbers “3” and “5” exist. Hence, the point data of the data number “4” is determined as the point data of the excluded subject. 
     In the present embodiment, as described above, it is determined whether each set of the point data stored in the traveling database  210  is the excluded subject. Accordingly, the traveling data storing server  200  in the present embodiment stores the point data determined as the not-excluded subjects in the rendering traveling database  220 . 
       FIG. 10  is a diagram illustrating an example of the rendering traveling database. The rendering traveling database  220  in the present embodiment is provided by corresponding to the traveling database  210 . Accordingly, it is preferable for the rendering traveling database  220  to store information indicating a correspondence to the traveling database  210 . Also, the rendering traveling database  220  may store identification information of the vehicle  10  included in the traveling database  210 , and thus may be associated with the traveling database  210  by the identification information of the vehicle  10 . 
     The rendering traveling database  220  in the present embodiment stores the point data determined as the not-excluded subjects from multiple sets of the point data being stored in the traveling database  210 . 
     In the example illustrated in  FIG. 10 , the point data of the data number “1” to be the start point of the traveling route, and, as illustrated in  FIG. 9  are stored, the data number “3” determined as the not-excluded subject and the point data of the data number “5”. 
     Also, referring to  FIG. 10 , the point data of the data number “2” and the data number “4” determined as the excluded subjects are not stored in the rendering traveling database  220 . Accordingly, the number of sets of the point data stored in the rendering traveling database  220  is decreased to be less than the number of sets of the point data stored in the traveling database  210 . Thus, the data amount is reduced. 
     The rendering process part  240  in the present embodiment renders the traveling route by referring to the rendering traveling database  220 . Compared with the rendering process referring to the traveling database  210 , it is possible to reduce load pertinent to the rendering process. 
     In the following, referring to  FIG. 11 , the process of the rendering process part  240  in the present embodiment will be described.  FIG. 11  is a flowchart for explaining a process conducted by the rendering process part. 
     The traveling data storing server  200  in the present embodiment determines, by the rendering process part  240 , whether the display request of the traveling route of the vehicle  10  is received (step S 111 ). In step S 111 , when the display request is not received, the traveling data storing server  200  waits until receiving the display request. 
     In step S 111 , when receiving the display request, the rendering process part  240  refers to, by the screen data generation part  241 , the rendering traveling database  220  corresponding to the vehicle  10  for which the display request of the traveling route is received (step S 112 ). 
     Next, the rendering process part  240  generates the screen data for the screen rendering the traveling route on a map by using the point data stored in the rendering traveling database  220  (step S 113 ). Map data for displaying the map may be stored in the traveling data storing server  200 , or may be acquired from an external server or the like. 
     Next, the rendering process part  240  outputs, by the screen data output part  242 , the generated screen data to a device that sent the display request (step S 114 ), and terminates this process. 
     As described above, the rendering process part  240  in the present embodiment refers to rendering traveling data, in which the point data of points other than the start point and the end point of a traveling route regarded as the straight line are excluded, based on all sets of the point data acquired by the mobile device  300 . Accordingly, it is possible to reduce the data amount to be used, and to reduce the load of the rendering process. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.